Table of contents :

• implantation of freshly isolated or cultured cells : individual cells or small cellular aggregates from the patient or a donor are either injected into the damaged tissue directly or are combined with a degradable scaffold in vitro and then implanted.
• in situ tissue regeneration : a scaffold implanted directly into the injured tissue stimulates the body's own cells to promote local tissue repair. The construction of stable blood vessels is a fundamental challenge for tissue engineering in regenerative medicine. Engineered blood vessels have often been found to be immature and unstable^ref
• genes that enhance the survival and/or proliferation of vascular cells - endothelial cells and mural cells - can be introduced to extend the lifespan of the engineered vessels^{ref1, ref2, ref3}, but these may prove to be oncogenic.
• a network of blood vessels stable and functional for one year in vivo can be formed in mice by co-implantation of human umbilical-vein endothelial cells (HUVECs) and 10T1/2 mesenchymal precursor cells in a 3D fibronectin-type I collagen gel^ref. The 10T1/2 cells differentiate into mural cells though heterotypic interaction with endothelial cells^{ref1, ref2, ref3}. To permit continuous observation of the engineered vascular networks in vivo, a 3D construct was implanted in mice bearing transparent "windows"^ref and the gene for EGFP was introduced in order to track the implanted HUVECs^ref. The likely existence of endothelial and of smooth-muscle progenitor cells in adults^{ref1, ref2} indicates that these cells might serve as a source of autologous cells for engineering blood vessels by using the approach described here.
• implantation of tissues assembled in vitro from cells and scaffolds (tissue engineering) : a complete 3D tissue is grown using patient or donor cells and a scaffold, and then is implanted once it has reached "maturity"

• implants : without restablishing vascular and nervous connections
• avascular graft / white graft : a graft of tissue in which not even transient vascularization is achieved
• corneal allograft
• full-thickness corneal allograft (lasting 30-40')
• penetrating graft
• lamellar allograft preserving Descement's membrane and corneal endothelium in recipient's cornea (lasting 2 hr)
As the cornea is not vascularized transplant rejection occurs in less than 5% of recipients and can be prevented with topical corticosteroids. Rejection is more frequent when cornea has become vascularized (eg. in herpetic keratitis). Quality directly relates with number of endothelial cells. Cornea can be included in a conservation medium (eg Optisal^®) for up to 1 week or in a culture medium for up to 1 month. A punch is used to cut a circular fragment from the donor cornea and a suction mechanical trapane is used to remove a same fragment from the recipient's cornea. The suture is left for 1 year^ref.
• dental implant : a prosthetic device of alloplastic material implanted into the oral tissues beneath the mucosal or periosteal layer or within the bone to provide support and retention to a partial or complete denture.
• endosseous implant / endosteal implant : a dental implant made of metal or sometimes ceramic or polymeric material, consisting of a blade, screw, pin, or vent, inserted into the jaw bone through the alveolar or basal bone, either directly or through the root canal and apex of a tooth, with a post protruding through the mucoperiosteum into the oral cavity to serve as an abutment for dentures or orthodontic appliances, or to serve in fracture fixation.
• endodontic implant : a metallic implant extending through the root canal of a tooth into the periapical bone structure, thereby lengthening the root of a pulpless tooth.
• intraperiosteal implant : a frame that conforms to the shape of the jawbone and is implanted beneath the outer or fibrous layer of the periosteum so that it rests firmly on the bone, with a post protruding into the oral cavity to serve as an abutment for dentures; used most commonly for upper fixed partial dentures and in the treatment of cleft palate.
• osseointegrated implant : an endosseous implant containing pores into which osteoblasts and supporting connective tissue can migrate. Metallic, ceramic, and polymeric materials have been used.
• Brânemark implant : a type of osseointegrated implant consisting of a two-stage system of titanium screws
• subperiosteal implant : a dental implant consisting of a metal frame implanted under the periosteum and firmly bound by the mucoperiosteum, resting on the jaw bone, with a post protruding into the oral cavity; used most commonly as an abutment for upper fixed partial dentures and in the treatment of cleft palate.
• transmandibular implant : a dental implant consisting of baseplate, cortical screws, threaded posts, and a superstructure that attaches to a denture, inserted via submandibular incision and fixed to the symphyseal border. The implant transverses the mandible, bears the denture directly, and is designed for patients with severe mandibular alveolar atrophy.
• Bosker implant : a common type of transmandibular implant.
• transosteal implant : a dental implant consisting of a bolt that crosses the mandible and is secured in place by a nut; a post protrudes into the oral cavity and serves as an abutment for dentures or orthodontic appliances.
• transplantations and transfusions : reestablished vascular and nervous connections

Donor and recipient : warm ischemia time (from arterial clamping to placement into cold organ perfusion solution) => cold ischemia time (CIT) (from placement into cold perfusion solution to beginning of vascular anastomoses in the recipient) => second warm ischemia (from beginning of vascular anastomoses to arterial declamping in the recipient)
• autotransplantation / autotransplant / autograft / autochthonous, autogenous or autologous graft (if the donor is the recipient itself : e.g. bone marrow, skin, ovary, spleen, parathyroid, fatty tissue, ...)
• syngeneic transplantation / syngraft / isograft and isogeneic, isologous, or syngeneic graft / isotransplantation : a graft between genetically identical individuals. Typically, syngrafts are grafts between monozygotic twins, between animals of a single highly inbred strain, or between F₁ hybrids produced by crossing inbred strains
• allogeneic transplantation / allotransplantation / allotransplant / allograft / homograft / homologous or homoplastic graft (if the donor belong to Homo sapiens species) : transplantation of an allograft; the 3 types are
• cadaveric donor transplantation : allogeneic transplantation of an organ or tissue from a cadaver
• grafts from heart-beating donors (HBDs) : heart => lungs => liver => pancreas => kidneys

Techniques :
• no touch fast technique (sequential surgical equipes) : median sternotomy => preparation of arteries; median xiphopubic laparotomy (also transverse incision in obese patients); preparation of inferior vena cava => exploration of abdominal cavity => cannulation of subrenal abdominal aorta and inferior vena cava in hemodynamically unstable patients; isolation of choledocus, hepatic artery, gastroduodenal, right gastric artery and subhepatic vein for liver explantation => ligation of inferior mesenteric artery => isolation and cannulation of inferior mesenteric vein for portal perfusion => cholecystotomy and lavage of bile from abdominal cavity with NS to prevent autolysis and liver damage => heparinization (3 mg/kg i.v.) (when the heart is explanted, phenothiazines cannot be administered) => placement of angiostat over supradiaphragmatic aorta and superior vena cava => discontinuation of systemic i.v. fluid infusion => cold perfusion with EW through subdiaphragmatic aorta (and, if portal vein is perfused, also through inferior mesenteric vein) => cardiectomy and pneumonectomy. Cooling of abdominal viscera can be enhanced by introduction of sterile ice into the abdominal cavity => ligation of right gastric and gastroduodenal artery and isolation of common hepatic artery until celiac trunk => pancreatectomy (the choledocus is sutured at the upper border of pancreas) and hepatectomy together with celiac trunk. Nephrectomy is performed at last. Incision of right parietocolic pouch => medial mobilization of ascending colon and terminal ilium => distal ligation of superior mesenteric artery => aortic clampage and cold perfusion => mobilization of asceding colon and sigma by incision of left parietocolic pouch along Toldt white line => ligation of inferior mesenteric vessels => kydneys are made free from retroperitoneum and psoas but still into Gerota's capsule (which is then removed at the bench). Ureters are sectioned just above the cupule of the urinary bladder to prevent excessive traction. Periureteral adipose tissue has to be preserved in the golden triangle (from distal ureter to lower renal pole) as the ureteral artery (emerging from the lower border of the renal artery) is the only one left for vascularization of ureter. For en-bloc explantation the left kidney and ureter are passed through an incision in the mesocolon. Aorta and inferior vena cava are sectioned distally to perfusion cannulas after looking for eventual lower polar arteries emerging from common iliac artery. The large vessels (still cannulated) and ureters are moved upward  => the posterior lumbar vessels are ligated and dissected => section of aorta and inferior vena cava just below diaphragm. At the bench the left renal vein (longer) is sectioned, while the right renal vein (shorter) is left attached to the inferior vena cava (sectioned just above the entry of the right renal vein and then used to enlenghten the right renal vein itself). The posterior face of the aorta is incised longitudinally between emergence of lumbar arteries beginnig from proximal aorta and respecting eventual anomal renal arteries. An aortic patch including the celiac trunk and the superior mesenteric artery is cut; a trasverse incision between the ostium of the superior mesenteric artery and the ostium of the renal arteries; a second transverse incision is practiced over aorta downstream of renal arteries to leave a wide patch around them. The 2 kidneys are then separated by a longitudinal incision in the anterior wall of the aorta between the ostium of the right and left renal arteries. The iliac arteries and veins are explanted en bloc leaving bifurcations intact : even the 2 larger saphena veins are explanted sectioning them 2 cm below the knee, as they could be useful for eventual successive vascular reconstructions at the bench in renal or other organ transplantation.

Complications :
• excessive resection of subhepatic vena cava and damage to right renal vein
• injury to eventual multiple renal vessels emerging from iliac arteries
• too wide resection of aortic patch by the liver surgeon damaging right renal artery
• total abdominal evisceration (TAE) (Nakazato : 2 surgeons required) : preliminary dissection performed by the surgeon and physician's assistant averaged 30 to 45 minutes before aortic cross-clamping. Removal of all abdominal organs (liver, kidneys, pancreas, bowel) en bloc averaged 16 to 24 minutes after aortic cross-clamping, depending on the speed of the thoracic procurement.^ref
• grafts from non-heart beating donors (NHBDs) preserving some brainstem functions

Techinique : a catheter is introduced in the femoral artery to make a fast cold perfusion contemporaneously administering heparin. After clamping of thoracic aorta, the kidneys are rapidly removed en bloc and separated at the bench
• [brephoplastic graft : the transplantation of tissue from an embryo or newborn to an adult animal]
In the early 1960s, cadaveric donations were thought to be impractical and impossible. Living donors were the only available source of organs for transplantation. At Massachusetts General Hospital, a liver was harvested from a police officer whose heart was beating but whose brain was deemed dead. This seminal event led to the development of the concept of brain death as death, rather than the cessation of circulation, which previously defined death. The concept of brain death greatly increased the number of organs available for donation and improved the preservation of harvested organs. Once the concept of brain death was established, a system for organ procurement was founded to ensure the quality and availability of organs as efficiently as possible.
Contraindications : well-differentiated thyroid papillary carcinomas > 1 cm in diameter, as well as follicular and medullary carcinomas (regardless their size and or clinical staging), present absolute contraindication to donation. Papillary microcarcinoma restricted to the thyroid gland (with no metastases in local lymph nodes) because of its specific behavior and almost always benign course, requires an individualized approach. It seemed that when a recipient is in a life-threatening condition, we should consider taking organs from a donor suffering of papillary microcarcinoma restricted to the thyroid gland.
• living donor transplantation : antiplatelet drugs should be discontinued 2 weeks before; oral contraceptives 6 weeks before; antihypertensive drugs should be reduced; the donor should by hydrated 2 hours before explantation to ensure a diuresis > 80-100 ml/hr; a broad-spectrum antibacterial (2nd or 3rd-generation cephalosporin) is administered and the lower limb are covered with elastic bandage to prevent PE from DVT.
• living related donor (LRD) transplantation / syngenesioplastic transplantation : allogeneic transplantation in which the donor and the recipient have a close biological relationship, such as that of a mother and her child or a brother and sister. With directed donation to loved ones or friends, worries arise about the intense pressure that can be put on people to donate, leading those who are reluctant to do so to feel coerced. In these cases, transplantation programs are typically willing to identify a plausible medical excuse, so that the person can bow out gracefully^ref. Equally important, however, are situations in which people feel compelled to donate regardless of the consequences to themselves. In one instance, both parents of a child who was dying of respiratory failure insisted on donating lobes of their lungs in a desperate but unsuccessful attempt to save her life (Kolata G. Lungs from parents fail to save girl, 9, and doctors assess ethics. New York Times May 20, 1991:A11). Such a sense of compulsion is not unusual. In cases like these, simply obtaining the informed consent of the relative is insufficient — physicians are obligated to prevent people from making potentially life-threatening sacrifices unless the chance of success is proportionately large.
• living nonrelated or unrelated donor (LNRD / LURD) transplantation : allogeneic transplantation in which the donors choose to give to a specific person with whom they have no prior emotional connection. This type of donation usually occurs when a patient advertises for an organ publicly, on television or billboards or over the Internet. Such advertising is not illegal, but it has been strongly discouraged by the transplantation community. 2 central objections are that the practice is unfair and that it threatens the view that an organ is a "gift of life," not a commodity to be bought and sold. Some argue that just as we have a right to donate to the political parties and charities of our choice, so should we be able to choose to whom to give our organs. In practice, however, this means that those who have the most compelling stories and the means to advertise their plight tend to be the ones who get the organs — rather than those most in need. This strikes some ethicists as unfair. Unlike monetary gifts, they argue, organ transplantation requires the involvement of social structures and institutions, such as transplantation teams and hospitals. Hence, the argument goes, these donations are legitimately subject to societal requirements of fairness, and transplantation centers should refuse to permit the allocation of organs on the basis of anything but morally relevant criteria^ref. The most ethically problematic cases are those in which the recipient is chosen on the basis of race, religion, or ethnic group. In one case, for example, the family of a brain-dead Florida man agreed to donate his organs — but insisted that because of the man's racist beliefs, the recipients must be white. Although the organs were allocated accordingly, Florida subsequently passed a law prohibiting patients or families from placing such restrictions on donation (Veatch RM. Transplantation ethics. Washington, D.C.: Georgetown University Press, 2000). Even when the motives for choosing a recipient may be unethical, however, there might be reasons for allowing the donation to proceed. Consider a case that was discussed at a recent public forum hosted by Harvard Medical School's Division of Medical Ethics: a Jewish man in New York learned of a Jewish child in Los Angeles who needed a kidney transplant. The man wanted to help someone of his own faith and decided he was willing to donate a kidney to help this particular child. Despite his discriminatory preference, one might view the donation as permissible, since at least some patients would benefit (the child would receive a kidney, and those below her on the waiting list would move up one notch) and no one would be harmed (those above the girl on the waiting list would not receive the kidney under any circumstances, because the man would not give it to them). Whether directed donation to strangers violates standards of fairness is thus controversial. But if it is permitted, it will be very difficult to prohibit discriminatory preferences, since donors can simply specify that the organ must go to a particular person, without saying why. The other substantial cause for concern about this type of donation is its potential for making possible the buying and selling of organs (see also organ trade). These practices are strictly prohibited by law, yet they seem to be an inherent risk in directed donations to strangers. Wealthy patients in need and healthy donors looking for a quick fix to their financial problems will always be able to find ways around even the most earnest attempts to prevent money from changing hands. Despite these concerns, efforts to direct organ donations to strangers are not new, dating back at least to the celebrated 1982 case of Jamie Fiske, whose father successfully mounted a nationwide appeal for someone to donate a liver to her. Today, many such solicitations are transmitted over the Internet, where, when the practice was relatively limited, organ solicitation was managed quietly, on a case-by-case basis, by individual transplantation centers. All this changed, however, with the emergence in 2004 of MatchingDonors.com (as discussed by Steinbrook in this issue of the Journal, pages 441–444). This Web site currently claims to have > 2100 registered potential donors and to have brokered 12 transplantations, with about 20 more recipient–donor pairs matched and awaiting surgery. Although the business conducted on this organization's Web site does not raise any fundamental ethical issues not already posed by other methods of solicitation, it does introduce a new degree of visibility that increases the magnitude of the issue. Will competing commercial Web sites begin to emerge? How will these sites be held accountable? Dr. Jeremiah Lowney, the medical director of MatchingDonors.com, recently argued that just as a dating service could not be held responsible for a bad date, his Web site has no responsibility for the outcomes of its matches. Furthermore, the Web site has no mechanism for ensuring the quality of the information it provides about transplantation and donation by living persons or for checking the accuracy of information submitted by potential donors and recipients. Given the life-or-death consequences of the procedure, organ donation should not be governed by the ethics of caveat emptor. Nevertheless, MatchingDonors.com has clearly identified a need, and if this need is not met by a service that can address the ethical challenges, the vacuum will be filled by other enterprises. Entrepreneurs commonly open up useful new markets and services that must eventually become subject to rigorous standards and regulations. The solicitation of organs over the Internet is probably here to stay, but it will require higher standards of responsibility and accountability than are currently in place. UNOS has > 20 years of experience in managing the cadaveric-donor pool and is in a good position to extend its jurisdiction to include donation by living donors. The organization recently considered the topic of solicitation and decided not to pursue building a Web site similar to that of MatchingDonors.com but, instead, to provide educational information for anyone who is willing to be a living donor of a kidney and to develop a nationwide mechanism for allocating organs for nondirected donation by living donors. This effort, however, does not go far enough. The proposal does not address directed donation and leaves many critical aspects of donation by living donors to the transplantation centers. Organ transplantation is big business, and each center is highly motivated to expand its share of the pie. They therefore have intolerable conflicts of interest when it comes to regulating themselves. Instead, UNOS should be charged with standardizing the process for evaluating potential donors, ensuring that independent advocates are assigned to help donors make an informed choice, developing mechanisms to deal with potential injury or death to the donor, setting standards for both directed and nondirected donation, and prohibiting transplantation when the chance of success is insufficient to justify the risks. Comprehensive oversight is necessary if the ethical pitfalls are to be adequately addressed^ref
• nondirected donation, in which the donor gives an organ to the general pool to be transplanted into the recipient at the top of the waiting list. The radical altruism that motivates a person to make a potentially life-threatening sacrifice for a stranger calls for careful scrutiny. One recent case involved a man who seemed pathologically obsessed with giving away everything, from his money to his organs, saying that doing so was "as much a necessity as food, water, and air." (Parker I. The gift: Zell Kravinsky gave away millions: but somehow it wasn't enough. The New Yorker. August 2, 2004:54-63). After donating one kidney to a stranger, he wondered how he might give away all his other organs in a dramatic suicide. Other psychologically suspect motivations need to be ruled out as well. Is the person trying to compensate for depression or low self-esteem, seeking media attention, or harboring hopes of becoming involved in the life of the recipient? Transplantation teams have an obligation to assess potential donors in all these dimensions and prohibit donations that arouse serious concern^ref.
Donable tissues : kidney, liver segment II, lung lobe, left pancreas, pancreatic islets
Epidemiology : today, according to the United Network for Organ Sharing (UNOS), almost half of all kidney donors in the USA are living. In 2004, living organ donors also provided a lobe of the liver in approximately 320 cases and a lobe of a lung in approximately 15 cases^ref.
Such grafts are invariably rejected unless the recipient is immunosuppressed, or the graft is to an immune-privileged site.
Click here for pathogenesis of transplant rejection.
Click here for danger theory.
Click here for Italian laws
Criteria for assignation :
• age
• compatibility
• human blood groups
• Rh group doesn't matter
• AB0 group : donor 0 to recipient 0 and B, donor A to recipient A and AB, donor AB to recipient AB, donor B to B and AB
• HLA types (HLA-A, HLA-B, HLA-DR), and MHC typization tools
• waiting time
Common contraindications for donors :
• cancers (breat cancer in females, prostate cancer in males), but nonmelanoma skin cancers is not a contraindication
• sepsis and infection from an antibiotic-resistant pathogen (body cooling impairs detection of many species), but localized infection at other body site is not a contraindication
• viral infections : HBV, HIV-1 patients may receive organs only in pilot programs, HCV patients may donate liver only for fulminating hepatitis, HHV-4 / EBV, HHV-5 / CMV, HHV-3 / VZV should be monitored
• some countries prevent inmates from donating organs
Overall donor risk :
• standard risk
• augmented risk : e.g. episodic finding of drug of abuse
• calculated risk : e.g. time elapsed since cancer remission
• unacceptable : e.g. HIV patients
• xenogeneic transplantation / xenotransplantation / xenotransplant / xenograft / heterograft / heterotransplantation / heterologous or heteroplastic graft (if the donor belongs to a species different from Homo sapiens)

"The dream of the ancients from time immemorial has been the junction of portions of different individuals, not only to counteract disease, but also to combine the potentials of different species. This desire inspired the birth of many mythical creatures which were purported to have capabilities normally beyond the power of a single species. The modern world has inherited these dreams in the form of the sphinx, the mermaid and the chimerical forms of many heraldic beasts." (Christiaan Barnard, 1967)^ref
History : because of the lack of donor organs, the use of biomechanical and nonhuman organs is being explored as a potential solution to this shortage. Xenotransplantation was actually performed long before clinical allotransplantation. In 1905, French surgeon Princeteau transplanted a slice of rabbit kidney into a uremic child. Despite noted improvement of renal function, the child died of pneumonia. Although many other examples of xenografts of different organs have been reported from this early period, human xenografts were quickly abandoned because they uniformly failed. More recently, in 1960, Reemtsma performed a kidney transplantation from a chimpanzee donor into a human recipient; aggressive immunosuppression led to a 9-month survival. In 1984, Bailey performed an orthotopic transplantation of a baboon heart into a human neonate with a hypoplastic left ventricle; the graft functioned for 20 days. Despite aggressive immunosuppression, graft failure occurred secondary to vascular rejection. A baboon-to-human liver transplantation was performed by Starzl in 1993. This graft functioned well for a time, although the patient died several months later from severe sepsis and organ rejection. Other xenotransplant efforts include transplantation of dopaminergic porcine fetal neural cells to the basal ganglia in order to treat Parkinson disease. Deacon et al performed one such transplantation in 1997. Cellular xenografts, such as pancreatic islet cell transplantation and neural cell transplantation, may be protected from rejection because of the absence of vascular tissues. In contrast, xenotransplantation may, in the future, be used as a lifesaving procedure for critically ill patients who are waiting for allografts but are dying because of the shortage of organs. This technique may be particularly helpful for patients with acute liver failure or cardiac failure^{ref1, ref2}
Hurdles to clinical xenotransplantation :
• size and function. Studies in which pig organs have been transplanted into nonhuman primates indicate that the kidneys,hearts, and lungs of pigs would function sufficiently well in a human to sustain life. By contrast, presumed incompatibilities between the complex metabolic systems of the pig and human liver would seem to preclude ready application of hepatic xenotransplantation. However porcine liver xenografts can function adequately in baboons, and pig hepatocytes have been observed to sustain the life of rats with cirrhosis. Even if physiological hurdles were found to be a barrier to xenotransplantation, genetic engineering could be applied to the roblem.
• immunotolerance can be established because the amount of nonspecific immunosuppression required to protect the organs from rejection would be clinically intolerable. The immune responses to xenotransplantation are much more severe than the immune responses to allotransplantation for at least 3 reasons :
• all individuals have innate immunity agains xenogeneic cells, and this innate immune response recruits adaptive immune responses against the graft mediating hyperacute rejection.
• xenogeneic transplants carry a diverse set of foreign antigens against which cellular and humoral immune responses can be elicited (in allotransplants, by contrast, the main foreign antigens are MHC antigens)
• immune regulation, which might partially control responses to allograft, might fail to do so in responses to xenografts
As the biological barriers to xenotransplantation depend, to a significant extent, on the way in which the graft is connected to the recipient, it is importtant to distinguish between
• isolated cell xenotransplants are nourished and maintained by the microenvironment, growth factors and ingrowth of capillaries of the recipient. On the other hand tissue xenotransplants are maintained by both donor and recipient growth factors, and have a mixed vascular supply, consisting of in-grown blood vessels of recipient origin and blood vessels formed by the spontaneous anastomosis of donor and recipient capillaries. In both cases xenotransplant failure may be due to
• primary non-function :
• inability of growth factors of the recipient to support newly implanted cells and/or failure of graft factors to support angiogenesis by host vessels.
• action of NK cells or recently activated T lymphocytes on the newly implanted graft
• action of complement on xenogeneic cells and tissue introduced into the blood (for example, pancreatic islets injected into the portal vein)
• cellular rejection
• whole-organ xenograft are connected to the recipient by anastomosis of large blood vessels of the donor and recipient. As aside from this connetion, the graft remains entirely of donor origin, organ xenografts are not generally compromised by incompatibility of the local environment in which they are placed and xenotransplant failure may be due to
• hyperacute rejection : the a-gal epitope (Gala1-3Galb1-(3)4GlcNAc-R) is abundantly synthesized on glycolipids and glycoproteins of non-primate mammals and New World monkeys by the glycosylation enzyme a1,3galactosyltransferase (a1,3GT). In humans, apes and Old World monkeys, this epitope is absent because the a1,3GT gene was inactivated in ancestral Old World primates. Instead, humans, apes and Old World monkeys produce the anti-Gal natural antibodies (nAb), which specifically interacts with a-gal epitopes and which constitutes approximately 1% of circulating immunoglobulins. Anti-Gal has functioned as an immunological barrier, preventing the transplantation of pig organs into humans, because anti-Gal binds to the a-gal epitopes expressed on pig cells. Binding of xenoreactive nAb to Gala1-3Gal activates complement and rapid insertion of terminal complement complexes in the cell membranes of the endothelial lining of blood vessels in the donor organ, which in turn causes graft destruction^ref. Approaches to prevention of hyperacute rejection include :
• xenoreactive antibodies (XA) can be depleted by column absorption
• complement can be inhibited by Cobra venom factor or soluble CR1 (sCR1), or genetic engineering of donor organs for the expression of the species-specific human complement-regulatory proteins DAF, CD59 / MIRL, and MCP.
• NK cells
• genetic engineering of a-1,3-galactosyltransferase 1 (GGAT1)^-/- pigs to eliminate Gal-a-1,3-Gal epitopes has become possible with cloning technologies. Anyway eliminating an antigen by gene targeting might uncover new epitopes!
• kidneys from GGAT1^-/- pigs enabled 8 baboons to survive for up to 81 days, compared with around 30 days for non-transgenic kidney (the longest that researchers have extended a baboon's life with a pig organ — although baboon-to-baboon transplants are still more successful). Along with the kidney, the researchers also transplanted pieces of pig thymus, which pump out immune cells that do not attack pig tissues.
• acute vascular rejection is caused by xenoreactive antibodies which bind to the xenograft causing activation of endothelium in the graft and possibly apoptosis. Approaches to prevention of acute vascular rejection include :
• pre-transplant infusion with donor haemotopoietic cells induces tolerance to Gal-a-1,3-Gal and other xenospecific antigens
• grafting donor bone marrow or stem cells, but the biological hurdles to engraftement of xenogeneic bone marrow cells, which include the action of antibodies and complement on the cells and the incompatibility of host growth factors, might make induction of tolerance to organ xenografts difficult to achieve.
• grafting donor thymus into initially immunocompetent recipients that are thymectomized and treated with T cell-depleting Abs allows reconstitution of the CD4 compartment, and these donor CD4 cells are rendered tolerant to donor-specific tissue. These hosts appear to have normal immunocompentece, in that they are capable of clearing opportunistic infections and responding to protein Ags presented by recipient class II MHC molecules. The donor thymus is not required to produce more T cells than normal syngeneic thymus to maintain a constant peripheral CD4 cell pool.
• knock-out of a-1,3-galactosyltransferase 1 (GGAT1) and possibly other pig genes to decrease antigen expression has become possible with cloning technologies. Anyway eliminating an antigen by gene targeting might uncover new epitopes !
• suppression of pro-coagulant or pro-inflammatory genes inhibits endothelial cell activation
• accommodation, an acquired resistance to humoral immune-mediated injury, has been induced by transient depletion of xenoreactive antibodies followed by the return of those antibodies without causing humoral rejection. In this setting, accommodation might be brought about by
• a change in xenoreactive antibodies
• a change in the antigens in the graft
• binding of xenoreactive antibodies or the action of inflammatory agonists, in subtoxic amounts induces changes in the graft, which make the graft inured to humoral injury.
• desensitization or loss of receptors for inflammatory agonists
• interruption of cell activation or effector pathways - for example, by IkB or BCL2
• production of proteins, such as CD59 / MIRL or haem oxygenase 1 (HO-1) that repair or block the detrimental effects of the agonists that would otherwise induce tissue injury
• cellular rejection
• chronic rejection : if it is caused by an immune response to the graft, as some experimental evidence indicates, then it should be common and severe in xenotransplants. If it is caused by qualities of the graft, such as preservation time, ischaemia and donor age, then it should not be much of a problem. In any case, because xenotransplantation offers an unlimited supply of organs, the impact of chronic rejection might be less serious as the chronically rejected organ can be replaced
• donor infectious organisms :
• chimpanzees (Pan troglodytes) : theoretically transmittable viruses
• simian immunodeficiency virus (SIV)
• cercopithecine herpes virus 1 / herpes virus B
• simian cytomegalovirus (SCMV)
• simian fomay virus
• monkeypox virus
• pigs (Sus scrofa) : the risk of the spread of pathogens should be less in xenotransplantation than in allotransplantation, because most pathogens of pigs do not infect humans, and because pigs can be raised to be free of known human pathogens. All pigs carry porcine endogenous retrovirus (PERV), but its potential effects on people are unknown and to date it has not been found to be transmitted to humans (strain A uses as receptors HuPAR-1 and HuPAR-2). In a model of human-pig chimerism, some human HSCs engrafted in pigs contain both human and porcine chromosomal DNA. These hybrid cells divide, express human and porcine proteins, and contribute to porcine nonhematopoietic tissues. In addition, the hybrid cells contain porcine endogenous retroviral DNA sequences and are able to transmit this virus to uninfected human cells in vitro. Thus, spontaneous fusion can occur in vivo between the cells of disparate species and in the absence of disease. The ability of these cell hybrids to acquire and transmit retroviral elements together with their ability to integrate into tissues could explain genetic recombination and generation of novel pathogens^ref.
• cows (Bos taurus)
Strategies :
• nuclei from a human patient might be transferred to enucleated stem cells of an animal, and the cells might then be grown in vitro or in an animal to generate differentiated human tissue that is autologous with the patient.
• pig embryonic tissues represent an attractive option for organ transplantation. However, the achievement of optimal organogenesis after transplantation, namely, maximal organ growth and function without teratoma development, represents a major challenge. Distinct gestational time windows were determinated for the growth of pig embryonic liver, pancreas, and lung precursors. Transplantation of embryonic-tissue precursors at various gestational ages [from E (embryonic day) 21 to E100] revealed a unique pattern of growth and differentiation for each embryonic organ. Maximal liver growth and function were achieved at the earliest teratoma-free gestational age (E28), whereas the growth and functional potential of the pancreas gradually increased toward E42 and E56 followed by a marked decline in insulin-secreting capacity at E80 and E100. Development of mature lung tissue containing essential respiratory system elements was observed at a relatively late gestational age (E56). These findings, showing distinct, optimal gestational time windows for transplantation of embryonic pig liver, pancreas, and lung, might explain, in part, the disappointing results in previous transplantation trials and could help enhance the chances for successful implementation of embryonic pig tissue in the treatment of a wide spectrum of human diseases^ref.
Web resources :
• Swine Leukocyte Antigen Database (SLAD)
• Bovine Leukocyte Antigens
Click here for ischemia reperfusion injury (IRI)
Placements :
• homotopic or orthotopic transplantation : transplantation of tissue from a donor into its normal anatomical position in the recipient.
• heterotopic transplantation :
• kidney transplantation
• experimental transplantation of tissue typical of one area to a different recipient site, usually a non-immune-privileged site
• subcutaneous tissue
• subcapsular space of the kidney
• mice given transplanted testicle tissue on to the backs are capable of growing mature goat, pig and monkey sperm 7 months later : this may one day help to preserve endangered species.
Good tissue practices (GTP) rule.
Transplanted material :
• cell transplantations (cell therapy)
• infusion graft : transplantation by injection of a suspension of cells
• adoptive transfer or adoptive immunization => adoptive immunity
• differentiated cells
• CNS neurons
• focal or regionally restricted neurologic diseases
• Parkinson's disease (PD) : the goal has been the engraftment and enhanced survival of dopamine-producing cells within the striatum, or by forestalling degeneration of dopaminergic neurons within the substantia nigra (SN). Anyway differentiated dopaminergic neurons don't survive after transplantation and some are rejected by the immune system. All strategies here reported didn't result in life quality improvement in double blind placebo-controlled trials even if neurons are alive and dopamine producing.
• xenogeneic pig neurons
• dopamine-producing cells from patient's own adrenal glands
• neurons from aborted fetuses (15-50% developed dyskinesias caused by overactive or poorly functioning neurons)
• dopaminergic neurons derived from cloned ES cells by
• transfection with a CMV plasmid driving expression of Nurr1 (a transcriptional factor involved in the differentiation of midbrain precursors into dopamine neurons)
• cell culture system that allows rapid and efficient derivation of most nervous system neural subtypes
• widely disseminated (in the brain and/or spinal cord) neurologic diseases (lysosomal storage diseases (LSD), leukodystrophies, inborn errors of metabolism, hypoxic-ischemic encephalopathy, Alzheimer's disease (AD), Huntington's disease (HD), multi-infarct dementia (MID), multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS), glioblastomas) : they have not typically been regarded as within the purview of neural transplantation
• transplantation of somatic cells derived from the hematopoietic system administered via bone marrow transplantation (BMT), with unsatisfactory results
• autologous skin cells genetically modified to express NGF when injected stereotaxically in up to 10 million numbers into 10 different brain sites they halve Alzheimer's disease (AD) patients' rate of mental decline 1 year on (by comparison, the best drug therapies offer only around a 5% decrease in the rate of decline) : brain scans also showed that the patients had more blood pumping around their brains than before their surgery, indicating that the injected cells were still alive and having an effect one year later. Skin cells are easy to obtain, culture and alter genetically and replicate when given space to grow in culture but stop dividing when they are implanted in the dense tissue of the brain, meaning that they are unlikely to form tumours : over time the transplanted cells may slow their production of NGF and be less effective
• neonatal pig choroid plexus cells encapsulated in alginate expressing neurotrophins has shown beneficial effects in rat^ref and primate models (225 nmol quinolinic acid injection in the ipsilateral striatum) for Huntington's disease (HD). Living Cell Technologies (LCT)'s (Auckland, New Zealand) BioPharma subsidiary in Providence, Rhode Island, which plans to carry out the human trials.
Glial scarring prevents implantation of transplanted neurons in both brain and retina.
• blood cells : the National and regional register of blood and plasma, established in 1991, makes it possible to know the production and distribution of blood and blood components in Italy. It represents an important instrument to programme the blood needs. The Register is filled out by every Transfusion Service (302 in 2004), according to the standard questionnaire established in the Minister Decree of 1996, it is sent to the relative Regional Health Board and, by this, to the Istituto Superiore di Sanità (the Italian National Institute of Health). The Register is essentially divided into two sections: the first one collects data concerning donors, donations, and plasma; the second one checks other important activities for the transfusion service (laboratory diagnostics, computerisation, quality controls, and committees for the good use of blood). In 2004 total donors were 1,451,641, blood donations were 2,274,513, and donations by aphaeretic procedures about 400,000. The amount of plasma produced was 725,112 litres, 531,395 of them were sent to industry for plasmaderivatives production. About 80,000 units of red cells were exchanged between regions to satisfy the national need^ref.
• RBCs
• transfusion : the introduction of whole blood or blood components directly into the bloodstream
• exchange, exsanguination, replacement or substitution transfusion / exsanguinotransfusion : repetitive withdrawal of small amounts of blood and replacement with donor blood, until a large proportion of the blood volume has been exchanged; used primarily in newborn infants with erythroblastosis fetalis and sometimes in patients with various other blood conditions
• fetomaternal transfusion : transplacental passage of fetal blood into the circulation of the mother; in small amounts it may go unnoticed, but in larger amounts it can cause anemia or edema in the fetus.
• direct or immediate transfusion : the transfer of blood from one person to another without use of an intermediate container or anticoagulant
• mediate or indirect transfusion : transfer of blood from a donor to a flask or other container, and then to the recipient
• intraperitoneal transfusion : infusion of blood into the peritoneal cavity
• intrauterine transfusion : transfusion performed on an unborn infant in utero, often referring to transfusion of Rh-negative blood into the infant's peritoneal cavity in the treatment of erythroblastosis fetalis in utero
• autotransfusion / autologous transfusion : reinfusion of blood or blood products derived from the patient's own circulation; contraindicated in neoplastic patients due to risk of spreading neoplastic emboli.
• intraoperative autotransfusion : the collection, processing, and reinfusion of a patient's blood shed from a wound or body cavity during surgery.
• postoperative autotransfusion : the collection, processing, and reinfusion of the patient's blood shed from the mediastinum following open heart or chest surgery or from the chest following traumatic hemothorax
Donors : every people aged 18-60 and weighing > 50 kg, with SBP = 110-180 and DBP = 50-100, can donate blood. Exclusions may be :
• temporary :
• pregnancy (1 year)
• abortion (1 year)
• menstruating women
• gastric ulcer or duodenal ulcer
• hypersensitivities
• vaccination and/or prophylaxis :
• anti-malaria vaccination (3 years)
• anti-polio vaccination (14 days)
• yellow fever vaccination (14 days)
• drugs :
• NSAIDs (5 days)
• tetracyclines (30 days)
• aspecific immunoglobulins (1 year)
• infectious diseases
• HHV-4 / EBV (1 year)
• rubella virus (3 months)
• HHV-3 / VZV (3 months)
• influenzavirus (7 days)
• Toxoplasma gondii (1 year)
• Brucella melitensis (2 years)
• Rickettsia spp. (1 year)
• major surgery (1 year)
• minor surgery (3 months)
• tattoos (6 months)
• earlobe hole (6 months)
• occasional sexual intercourse (1 year)
• acupuncture (6 months)
• transfusion (5 years)
• permanent exclusion
• drug or alcohol addiction
• epilepsy
• severe diabetes mellitus
• severe systemic arterial hypertension or treatment with b-blockers
• autoimmune diseases
• diffuse dermatoses
• severe rheumatic diseases
• acting or previous hepatitis B or hepatitis C
• neoplasms
• cardiovascular diseases
• severe hematological diseases
• chronic nephropathies
• mental instability
• severe dysendocriniae
Donation of 1 unit (350 ml) of whole blood causes a reduction of 1 g/dl of hemoglobin in the donor after 24 hrs.
• platelets :
• neutrophils : use of recombinant G-CSF to stimulate donors, have made it possible to collect extraordinarily large numbers of normal neutrophils for transfusion into neutropenic patients with life-threatening infections. Because larger doses of neutrophils can be transfused, renewed interest has arisen in the use of neutrophil (granulocyte) transfusions to treat adult oncology patients and progenitor cell transplant recipients, in whom neutropenia complicated by severe infections persists as a significant problem, despite combination antibiotic therapy, recombinant cytokines, myeloid growth factors, and use of mobilized peripheral blood progenitor cells.
• natural killer (NK) cells : purification of human NK cells from leukopheresis products using a clinical-scale 2-step immunomagnetic method :
• CD3⁺ cells are first depleted and then CD56⁺ cells are enriched from the CD3⁺ cell-depleted products. The median percentage of CD3^-CD56⁺ NK cells in the final products is 91.0%, and the median recovery was 48.7%. The median depletion for CD3⁺CD56^- T cells was 5.3 log. Natural cytotoxicity of the purified cells us approximately 5-fold higher than that of unpurified mononuclear cells, and it could be further increased by stimulation of the purified cell with IL-2^ref
Complications :
• immediate reactions
• febrile nonhemolytic transfusion reaction (FNHTR) (1–4:100)
• allergic (1–4:100)
• delayed hemolytic (1:1,000)
• transfusion-related acute lung injury (TRALI) (1:5,000)
• acute hemolytic (1:12,000)
• fatal hemolytic (1:100,000)
• anaphylactic (1:150,000)
• post-transfusion purpura
• acute pulmonary edema, acute renal failure
• transfusion-associated transmission (TAT) of hematogenous infections
• HBV (1:63,000)
• HCV (1:1,600,000)
• HIV-1 (1:1,960,000)
• HIV-2 (none reported)
• HTLV-I and -II (1:641,000)
• malaria (1:4,000,000)
• infectious agents rarely associated with transfusion, theoretically possible or of unknown risk include: HAV, parvovirus B-19, Babesia microti (babesiosis), Borrelia burgdorferi (Lyme disease), Trypanosoma cruzi (Chagas disease), and Treponema pallidum subsp.pallidum, HHV-8 and HGV.
• other complications
• RBC allosensitization (1:100)
• HLA allosensitization (1:10)
• post transfusion graft-versus-host disease (PT-GVHD) / transfusion associated graft versus host disease (TA-GVHD) (rare) : a serious complication of blood transfusion with a high mortality rate. It occurs when immunologically competent lymphocytes from the donor are introduced into an immunoincompetent host who is unable to destroy the donor lymphocytes. The donor lymphocytes engraft, recognize the host as foreign and then attack host tissues. GVHD occurs most commonly after allogenic HSCT and less often after transfusion of non-irradiated cellular blood components especially when the blood donor and recipient share similar HLA antigens^ref. In this case, the recipient does not recognize the transfused donor cells as foreign and cannot reject them. The transfused viable T-cells react against the second haplotype on HLA that are not shared, with the resulting clinical picture of TA-GVHD^ref. Involvement is multi-systemic and patients usually present with high grade fever, a maculopapular erythematous scaly rash, hepatocellular damage with elevated hepatic enzymes, profuse and acute onset diarrhea and hematological manifestation in the form of pancytopenia and its resulting complications^ref. Histological changes are non-specific and primarily affect the skin, liver and the gastro-intestinal tract^ref. Characteristic changes in the skin include epidermal basal cell vacuolation; mononuclear cell infiltration in the epidermis and degeneration of the epidermal basal layer. Bulla formation and ulceration of the skin may also be seen. The liver may show degeneration of the small bile ducts and periportal mononuclear infiltrates associated with hepatocellular and cholangiolar cholestasis. The bone marrow may be hypocellular or aplastic with a lymphocytic or histiocytic infiltration along with haemophagocytosis^ref. Other predisposing factors of GVHD are congenital or acquired immunodeficiency, young age and transfusion with fresh whole blood^{ref1, ref2}. Multi-systemic involvement (bicytopenia, maculopapular erythematous rash, fever, watery diarrhea and jaundice following the blood transfusions with related donor) and the high mortality rate associated with this condition necessitates that pediatricians should be aware of this largely preventable condition^{ref1, ref2}. Clinical signs and symptoms in the initial phase can be confused with a variety of other conditions like Stevens Johnson syndrome, viral infections, drug reactions & reactive and familial erythrophagocytic syndromes. Hence a high index of clinical suspicion and relevant pathological support is required for its diagnosis. TA-GVHD has been reported from India in 3 full term neonates, all of whom died^{ref1, ref2}. Corticosteroids, antithymocyte globulin, cyclosporine and/or growth factors have been recommended for treatment either singly or in various combinations. However, attempts at treatment of TA-GVHD are largely ineffective. Newer modalities that have been tried include nafmostat mesilate, chloroquin and daclizumab. Irradiation of blood products prior to transfusion has reduced if not eradicated transfusion- related GVHD^{ref1, ref2}. Other methods under investigation include photoinactivation with the use of psoralen S59 with UV-A light, or the use of photoactive phenothiazine dyes^ref. The rapid downhill course, poor response to therapy and high mortality associated with transfusion associated graft versus host disease make its prevention a priority. Therefore optimizing blood/component use, reducing inappropriate transfusions and more importantly avoiding the use of related donors for transfusions is a more realistic option of preventing transfusion associated graft-versus-host disease in clinical practice.
Risk prevention : some 60% of global blood supplies go to 18% of the world's people, leaving 82% of the global population inadequately covered. So far, only 40 countries have established a 100% voluntary blood donation system, and < 30% of countries have a nationally coordinated blood transfusion service in place. HIV-contaminated blood still accounts for approximately 5% of HIV infections in Africa. While in many countries more and more testing is being done to make blood safe, the WHO said most developing nations do not test for diseases such as HIV-1 or HBV and HCV. Annually, some 6 million tests that should be done for infections are not done
• presumptive viremic blood donors (PVDs)
• testing of blood donors for HIV-1 and HCV RNA by means of nucleic acid amplification was introduced in the United States as an investigational screening test in mid-1999 to identify donations made during the window period before seroconversion : minipool nucleic acid–amplification testing has helped prevent the transmission of approximately 5 HIV-1 infections and 56 HCV infections annually and has reduced the residual risk of transfusion-transmitted HIV-1 and HCV to approximately 1 in 2 million blood units^ref. The prevalence rates of HBV, HCV, HIV-1, and HTLV infections are lower among tissue donors than in the general population. The prevalence of confirmed positive tests among tissue donors was 0.093% for anti-HIV, 0.229% for HBsAg, 1.091% for anti-HCV, and 0.068% for anti-HTLV. The incidence rates were estimated to be 30.118, 18.325, 12.380, and 5.586 per 100,000 person-years, respectively. The estimated probability of viremia at the time of donation was 1 in 55,000, 1 in 34,000, 1 in 42,000, and 1 in 128,000, respectively. However, the estimated probability of undetected viremia at the time of tissue donation is higher among tissue donors than among first-time blood donors. The addition of nucleic acid–amplification testing to the screening of tissue donors should reduce the risk of these infections among recipients of donated tissues^ref.
• precautionary measure to safeguard the blood supply have been taken in the light of the 1st possible transmission of new variant Creutzfeldt-Jakob disease (vCJD) by blood transfusion, which was reported in December 2003. The transfusion occurred in 1996; the blood donor was well at the time but developed symptoms of vCJD in 1999 and died the following year. The recipient was diagnosed with vCJD in 2003. Since 1997, in view of the uncertainty as to whether vCJD could be transmitted by blood or blood products, the UKBS have put in place a number of other measures to reduce the risk of a potential onward cycle of transmission :
• withdrawal and recall of any blood components, plasma derivatives, or tissues obtained from any individual who later develops vCJD (December 1997);
• importation of plasma from the US for fractionation to manufacture plasma derivatives (announced May 1998, implemented October 1999);
• leucodepletion (removal of white blood cells) of all blood components (announced July 1998, implemented Autumn 1999);
• pmportation of fresh frozen plasma from the United States for patients born on or after 1 Jan 1996 (announced August 2002, to be implemented spring 2004);
• promotion of appropriate use of blood and tissues and alternatives throughout the National Health Service (NHS).
Starting on 5 April 2004, the UK government is to ban people who have received blood transfusions since 1980 from donating blood, based on the premise that BSE did not emerge in Britain until after this date^{ref1, ref2}. The new move will exclude some 52,000 donors, prompting concern that vital bloodstocks will fall : only 6% of the eligible population give blood, so there's a real need to recruit new donors. This is a highly precautionary approach, and the benefit of receiving a blood transfusion when needed far outweighs any possible risk of contracting vCJD. To date there has been only one possible case of vCJD being transmitted by blood, yet the UKBS issue over 2.5 million units of blood every year.
• in the USA between 1986 and 1991 there were 29 deaths related to the bacterial contamination of blood or blood products. This represented about 16% of the transfusion-related fatalities during that time period. 8 of the 29 deaths (1-2 fatalities per year) were related to contaminated red cell products, a risk of 1 death per 9 million red cell transfusions. 7 of the 8 episodes were due to Yersinia enterocolitica. Other Gram-negative bacilli that have been implicated are Serratia spp., Enterobacterspp., and Pseudomonas spp. The source of the organism is thought to be asymptomatic transient bacteremia in the donor. Of note, most of the episodes occurred in blood older than 25 days. It has been demonstrated that at 4°C storage, Yersinia can multiply to high concentrations. Typically, fever and rigors occur within 30' of the transfusion and may rapidly progress to systemic arterial hypotension, disseminated intravascular coagulation, acute renal failure, and death : the organism was isolated from the patient's blood and the red cell transfusion. In a report from New Zealand, the fatality rate was 1 per 104,000 per red cell transfusion, a rate 80 times higher than in the USA. The other 21 deaths were related to platelet transfusions, translating into a fatality rate of 1 per 1 million platelet transfusions. The microbiology of these episodes was more variable, including a variety of Gram-negative bacilli (but not Y. enterocolitica), Staphylococcus spp., and Streptococcus spp.
Click here for Italian laws
Web resources :
• American Association of Blood Banks (AABB)
• American Red Cross
• UK National Blood Service
• UK Dept of Health : Protecting Blood Supplies
• Journals :
• Transfusion Medicine
• Transfusion Science
• bone marrow stromal cells (BMSCs) undergo best engraftment through subcutaneous implantation in a 3D matrix scaffold (collagen sponge, hydroxyapatite particles, hyaluronic acid sponge, ...) rather than intravenous infusion. It is conceivable that the former way not only avoids the loss due to the fact that BMSCs are not normally circulating cells unable to cross the endothelial wall, but also lets the cell create a local microenvironment that enhances cell survival. BMSCs are known to inhibit allogeneic T-cell responses and are therefore being investigated to promote haematopoietic engraftment when co-transplanted with HSCs in BMTs. Previous controversial reports have indicated that TGF-b₁ and HGF might be responsible for this effect. Expression and activity of indoleamine 2,3-dioxygenase (IDO) is upregulated in BMSCs after exposure to low levels of IFN-g, which can be generated by allogeneic T cells. IDO is responsible for the catabolism of tryptophan, which has previously been identified as a T-cell inhibitory effector mechanism. The fact that IDO is not constitutively expressed by BMSCs should enable this inhibitory mechanism to be modulated depending on the therapeutic application^ref.
• muscle-derived stem cells (MDCs) : one of the major obstacles in engineering thick, complex tissues such as muscle is the need to vascularize the tissue in vitro. Vascularization in vitro could maintain cell viability during tissue growth, induce structural organization and promote vascularization upon implantation. The induction of endothelial vessel networks has been reported in engineered skeletal muscle tissue constructs using a 3D multiculture system consisting of myoblasts, embryonic fibroblasts and endothelial cells coseeded on highly porous, biodegradable polymer scaffolds. Analysis of the conditions for induction and stabilization of the vessels in vitro showed that addition of embryonic fibroblasts increased the levels of VEGF expression in the construct and promoted formation and stabilization of the endothelial vessels. Prevascularization improved the vascularization, blood perfusion and survival of the muscle tissue constructs after transplantation of the engineered muscle implants in vivo in 3 different models^ref.
• autologous muscle-derived cells for stress urinary incontinence^{ref1, ref2, ref3, ref4, ref5, ref6, ref7, ref8, ref9, ref10}
• allogeneic myocytes in Duchenne's muscular distrophy (DMD)
• donor-matched arteries grown in vitro from human muscle cells transfected with hTERT and seed on a hose-shaped scaffold of biodegradable polymer. After 2 months, the support dissolves leaving a dense, muscular, tubular structure. Lining cells are then dropped inside to complete the artificial artery^ref
• allogeneic hepatocytes in the treatment of cirrhosis caused by hepatitis viruses. In such cases, xenogeneic hepatocytes might be preferred over human hepatocytes to avoid reinfection by human viruses.
• dura mater allograft :
• Lyodura^® (B. Braun Melsungen AG, Melsungen, Germany)
• autologous periosteum
• Neuropatch^® (B. Braun Melsungen AG)
• Dacron^® (E.I. du Pont de Nemours and Co., Wilmington, DE)
• Ethisorb^® (Ethicon, Inc., Somerville, NJ).
• Tutoplast^® fascia lata (Tutogen Medical, Inc.)
• Tutoplast^® dura (Tutogen Medical, Inc., Parsippany, NJ). The Tutoplast^® process :
• stage 1 (delipidization) : grafts are bathed in acetone and agitated with ultrasound.
• removes fat, which interferes with healing
• inactivates viruses
• prepares tissue so that subsequent steps penetrate the graft more effectively
• stage 2 (osmotic contrast treatment) : this step is unique to the Tutoplast process, enabling us to remove more antigenicity than any other allograft provider. Grafts receive alternating baths of distilled water and saline. This disrupts the bioburden cell wall integrity and exposes intracellular material for removal or destruction in this step and subsequent steps
• kills bacteria
• destroys and removes unwanted cells
• removes most antigenicity
• further reduces the viral load
• stage 3 (oxidation treatment) : in this step, grafts are bathed in a hydrogen peroxide (H₂O₂) wash.
• destroys remaining proteins
• removes residual antigenicity
• inactivates any remaining viruses exposed during the osmotic bath
• minimizes the potential for graft rejection
• stage 4 (solvent dehydration) : grafts receive a series of 7 acetone baths.
• removes all water from tissue, making graft storable at room temperature for 5 years
• ensures inactivation of any remaining prions or viral agents exposed during the osmotic bath
• preserves the dense collagenous fiber structure of the graft, retaining the original tissue strength
• stage 5 (limited-dose gamma irradiation) : grafts receive low-dose g irradiation (17.8 kGy) in a narrow, rotating sterilization system.
• minimizes irradiation to ensure biomechanical integrity of the allograft1
• eliminates reliance on aseptic process and collection methods
• guarantees sterility following cutting and packaging
• inactivates all remaining viruses
• stem cells

They can can be used to ...
• ... replace cells and cell circuits
• ... create host environments sufficiently rich in trophic and/or neuroprotective support to promote the recovery of damaged (though not died) endogenous cells
• ... practice gene therapy
• ... replace genes, including those coding for ECM molecules (secretion gene therapy for cross-correction of genetic metabolic defects)
• ... deliver antiviral genes (eg IFN-a)
Kinds of stem cells :
• fetal skin cells allotransplantation : the source of the healing cells may prove controversial in countries such as the USA, however, as they came from an aborted fetus. Doctors typically treat deep second- and third-degree burns with skin grafting. In this 2-step surgical procedure a patch of skin is removed from one area of the body and transplanted to cover the wound. This can be effective, but often leaves the patient with a scar and may take months to heal. Fetuses have long been known to have remarkable regenerative abilities, but the cells seemed to confer restorative powers to the burnt skin, allowing the damaged tissue to heal itself. The team doesn't know exactly how the skin cells had this effect. But the technique could work for adult burns, as well as other wounds. The team obtained the fetal cells from a woman whose pregnancy was terminated at 14 weeks. They allowed the cells to divide in the laboratory, and then seeded them onto a bed of collagen - an important protein for skin elasticity - and incubated them for 2 days. This procedure can source several million 100-cm² patches for transplant from a single fetal biopsy. 8 burn victims, ranging in age from 14 months to 9 years, underwent treatment. Tiny swatches of cells were placed onto the burn wounds and covered the area with gauze. The treated wounds took an average of 15 days to heal. Other forms of treating similar burns frequently take up to 6 times as long. The remarkable flexibility of the skin mended with the fetal cells meant that the patients recovered full movement of their hands and fingers. The result not only gave the patients nearly perfect skin, but also spared them the trauma of having a graft taken from elsewhere on their body^ref
• ESCs : there are some roadblocks that currently prevent researchers from putting the cells into patients' bodies :
• immune tolerance : human embryonic stem cells (hESCs) are envisioned to be a major source for cell-based therapies. Efforts to overcome rejection of hESCs include nuclear transfer and collection of hESC banks representing the broadest diversity of major histocompatability complex (MHC) polymorphorisms. Anyway injection of hESCs into immune-competent mice is unable to induce an immune response. Undifferentiated and differentiated hESCs fail to stimulate proliferation of alloreactive primary human T cells and inhibit third-party allogeneic dendritic cell-mediated T-cell proliferation (e.g. after LPS challenge) via cellular mechanisms independent of secreted factors. Upon secondary rechallenge, T cells cocultured with hESCs are still responsive to allogeneic stimulators but fail to proliferate upon re-exposure to hESCs^ref. Expression of CD178 / FasL by ES-like cells allows they to escape immune surveillance, allowing second-set allograft acceptance in experimental models. However, this may not be true of the differentiated tissue derived from the ESCs. The creation of a large pool of ESCs lines would increase the chances of matching MHC antigens. Otherwise immune tolerance can be obtained by :
• eliminating or introducing surface antigens through genetic engineering, but this might lead to genetic instability over time. Interestingly, although compared with somatic cells, ESCs develop a relatively small number of mutations (typically restricted to deletion of a chromosome that is replaced by a second copy of the remaining one) they increase with time in culture.
• cell nuclear replacement (CNR) / nuclear-transfer cloning (i.e. introduction of a nucleus from adult cell into an enucleated oocyte). Anyway some countries ban human cloning without drawing a distinction between cloning for reproductive or for therapeutic purposes, preventing it. It further implies ethical issues about practices to get oocytes (eventually from non-human females) and creation of human embryos for the sole purpose of destroying them to obtain replacement cells for the patient who provided the nuclear DNA.
• how to control the cells' transformations into other types : maintenance of pluripotency in human and mouse ES cells (HESCs and MESCs) can be achieved through functionally reversible activation of Wnt signalling (downregulated upon differentiation) by a pharmacological GSK-3 inhibitor. Although Stat-3 signaling is involved in MESC self-renewal, stimulation of this pathway does not support self-renewal of HESCs
• ES cells cannot be grown without help from mouse feeder cells, which means that they could be contaminated with mouse proteins.
Examples :
• generation of confluent cardiomyocyte monolayers derived from ESCs clone in suspension carrying a construct consisting of the a-cardiac myosin heavy chain (aMHC) promoter driving the neomycin resistance gene was used for antibiotic-driven cardiomyocyte enrichment => cardiac bodies (CB) => seeding of cardiomyocytes with 7 x 10⁴ cell/cm² resulted in a homogeneous monolayer of synchronously contracting cells^ref.
• Id knockout mouse embryos display multiple cardiac defects, but mid-gestation lethality is rescued by the injection of 15 wild-type embryonic stem (ES) cells into mutant blastocysts, allowing some of the offspring to survive for 2 days after birth. Myocardial markers altered in Id mutant cells are restored to normal throughout the chimeric myocardium. Intraperitoneal injection of ES cells into female mice before conception, which travelled across the placenta into the babies, also partially rescues the cardiac phenotype with no incorporation of ES cells. IGF-1, a long-range secreted factor, in combination with WNT5a, a locally secreted factor, likely account for complete reversion of the cardiac phenotype. Thus, ES cells have the potential to reverse congenital defects through Id-dependent local and long-range effects in a mammalian embryo^ref. This implies that doctors could simply inject these proteins, or otherwise mimic their effects with drugs, and would not need to inject stem cells at all, or mothers might boost their levels of IGF-1 by changing their diet or taking a drug. A reduction of just 15-20% of the Id protein impairs the stem cells’ ability to rescue these embryonic mouse heart cells. IGF-1 injected into the mother can cross the placenta and influence fetal cardiac development in the Id knock-out embryo.
• around 300,000 neural stem-cells from 16- to 20-week-old human fetuses cultured with growth-promoting chemicals were transplanted into rat brains 7 days after surgically inducing a stroke. 1 month later, an average of 100,000 of the grafted cells were still alive in the rats' brains and nearly half of them had turned into neurons. The remaining cells still looked like stem cells or had turned into astrocytes, a type of brain cell that supports neurons. Some grafted cells had migrated a millimetre or more away from the injection site towards the damaged part of the brain^ref. The next step is to prove that the cells can reverse paralysis in the rodents, before moving on to primate and human trials. Fetal stem cells have advantages over adult and embryonic alternatives. Adult stem cells do exist in the brain, but they are difficult to obtain, survive less well after transplantation and may be less versatile than their younger counterparts. Hundreds of millions of cells would need to be grown for human clinical trials and it is not clear whether these cells are capable of growth on that scale. Prolonged culture periods can slow cell growth and may give the cells a chance to pick up random genetic abnormalities : another approach would be to add a gene to the stem cells that boosts growth and prevents the formation of genetic defects
• human ESCs transfected with TRAIL gene and injected into mice with brain tumours, home in on the cancer and pump out enough TRAIL to cut the tumour size by an average of 50%, and up to 70% in some cases. The cells are thought to track the tumour by following chemical signals emitted by the immune system molecules that attack, but ultimately fail to destroy, the cancer. Stem cells could be modified to express other anticancer molecules, or a combination of cells, each equipped with different molecules, could be used in concert.
• ESCs are currently the most promising donor cell source for cell-replacement therapy in Parkinson's disease^{ref1, ref2}. A strong neuralizing activity present on the surface of stromal cells, named stromal cell-derived inducing activity (SDIA), has been described. Neurospheres composed of neural progenitors from monkey ES cells, which are capable of producing large numbers of DA neurons, have been generated. FGF20, preferentially expressed in the substantia nigra^ref, acts synergistically with FGF2 to increase the number of DA neurons in ES cell-derived neurospheres. We also analyzed the effect of transplantation of DA neurons generated from monkey ES cells into 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-treated (MPTP-treated) monkeys, a primate model for PD. Behavioral studies and functional imaging revealed that the transplanted cells functioned as DA neurons and attenuated MPTP-induced neurological symptoms^ref.
• ESCs from mice can help mend the broken hearts of sheep. This cross-species experiment is one more step in finding out whether hESCs can mend the damage done by heart attacks. A heart attack damages the muscle and blood vessels that allow a heart to pump blood around the body. Doctors have long sought a way to repair this damage, and some experts say that ESCs hold the answer. Studies have already shown that ESCs can improve blood flow after an attack in small animals, such as rodents^ref. But in people, ethical controversies have slowed research into the benefits of ESCs for ailing hearts. In human trials scientists have used stem cells from a patient's bone marrow to help the healing. These cells are not as flexible as embryonic ones, but can sometimes be persuaded to turn into the desired cell types. Patients treated this way are able to pump more blood after a heart attack than those who don't get the treatment. But researchers hope that ESCs might have a greater effect. ESCs were tested in sheep to see how well they work in large mammals. Because there is not much call for sheep ESCs, they are hard to source, so the team used mouse cells instead. The researchers injected about 30 million cells into the hearts of 9 sheep that had suffered heart attacks. They found that the sheep pumped blood through their hearts 15% more efficiently than the untreated sheep a month after the injections. Distinctive markers from the stem cells were found inside the sheep hearts, proving that the stem cells had gone to work and replaced some of the damaged tissue^ref. For the moment, the improvement is of the same order of magnitude as that achieved in humans with HSCTs. But the healing should increase over time: other studies have shown the biggest benefit from stem cells 2 months after injections. This form of cardiac therapy holds much future promise. He and his colleagues are currently conducting tests to assess the healing power of hESCs in baboons.
Web resources : World Stem Cell Hub
• olfactory ensheathing glial cells (OECs) : neurosurgeon Huang Hongyun at Chaoyang Hospital Beijing, China, have used fetal tissue transplants to treat more than 450 patients from 2002 to 2004. About 1 to 1.5 million cells are injected per injection site. There is no evidence that injecting more cells would attain better results : an Australian group had done a similar procedure on 3 patients, giving 10 injections and injecting 10 to 15 million cells, but that's a large volume and not good for the spinal cord. No controlled clinical trials have been carried out, although Huang is talking with the Miami Project to Cure Paralysis about designing such studies. In the Chinese Medical Journal in 2003, Huang published a report showing results in 171 spinal cord inury (SCI) patients, 2 to 8 weeks after transplantation. The study used the International Standards for Neurological and Functional Classification of Spinal Cord Injury scale, which gives a best total score of 100 for motor function and 112 for pin-prick (light-touch) sensation. Huang did not report baseline scores, but after OEC transplantation, motor scores increased by 8.3 in patients aged 21 to 30 years and 5.7 in those aged 31 to 40 years. Light-touch scores increased by 15.5 and 12.0 in the same groups^ref. His results represent a credible phase 1 trial that establishes the safety and feasibility of such transplants. Preliminary analyses of the results suggest that the procedure may produce rapid but modest sensory and motor improvements in people from 2 to 40 years after injury
• for amyotrophic lateral sclerosis (ALS), patients, 3 incisions are made, 2 in the frontal lobe (where atrophy is greatest) and the third at the spinal cord around mid-neck, for a total of up to 4.5 million cells
• spinal cord inury (SCI) patients get injection in the spinal cord close to the site of injury, for a total of a total of 1-1.5 million cells
• stroke
• multiple sclerosis (MS)
• cerebral palsy
• brain injuries
• ASCs : since many stem cells are capable of travelling widely within the body and perhaps transdifferentiating into diverse cell types within several organs, there is therefore a need for some mechanism to prevent inappropriate gene expression within these organs (obviously without altering the trafficking and transdifferentiating properties of BMSCs) :
• partial differentiation of BMSCs ex vivo before reintroduction
• identification of a specific BMSC population with a propensity to differentiate into the cell type of choice
• to use tissue-specific promoters
• hematopoietic stem cell (HSC) transplantation (HSCT / HCT)
• mesenchymal stem cells (MSC) are not immunogenic, they do not stimulate alloreactivity, and they escape lysis by CTL and NK-cells. Thus, MSC may be transplantable between HLA-mismatched individuals without the need for host immunosuppression. MSC obtained from human bone marrow have been described as adult stem cells with the ability of extensive self-renewal and clonal expansion, as well as the capacity to differentiate into various tissue types and to modulate the immune system. Some data indicate that leukapheresis products may also contain non-hematopoietic stem cells, as they occur in whole bone marrow transplantation (BMT). However, there is still controversy whether MSC expand in the host after transplantation like blood progenitor cells do. Every sample from total bone marrow transplants exhibited growth of MSC after in vitro culture, but not one of 9 leukapheresis products did. In addition, bone marrow aspirates of 9 patients receiving BMT and of 18 patients after PBSCT were examined for origin of MSC. Almost all MSC samples exhibited a complete host profile, whereas peripheral blood cells were of donor origin. Even if trace amounts of MSC are co-transplanted during PBSCT or BMT, they do not expand significantly in the host bone marrow^ref.
• adult MSC appear to be immunosuppressive as they reduce alloreactivity and the formation of CTLs in vitro. In vivo, adult MSC prolong the time to rejection of mis-matched skin grafts in baboons. The immunosuppressive properties of first trimester fetal MSC are less pronounced, but inducible with IFN-g^ref. They possess unique immunomodulatory properties, being capable of suppressing T cell responses and modifying dendritic cell differentiation, maturation, and function, while they are not inherently immunogenic, failing to induce alloreactivity to T and freshly isolated NK cells. To clarify the generation of host immune responses to implanted MSCs in tissue engineering and their potential use as immunosuppressive elements, the effect of MSCs on NK cells was investigated. At low NK-to-MSC ratios, MSCs alter the phenotype of NK cells, suppress proliferation, cytokine secretion and cytotoxicity against HLA-class I expressing targets. Some of these effects require cell-to-cell contact, while others are mediated by soluble factors, including TGF-b₁ and PGE₂, suggesting the existence of diverse mechanisms for MSC-mediated NK cell suppression. On the other hand, MSCs are susceptible to lysis by activated NK cells. Overall, these data improve our knowledge on interactions between MSCs and NK cells, and consequently on their effect on innate immune responses and their contribution to the regulation of adaptive immunity, graft rejection and cancer immunotherapy^ref.
• repair of damaged mesenchymal tissues
• (congestive) heart failure (CHF) patients underwent bypass surgery : injections into sites where there was obvious muscle damage leads to bettere recovery. Recipients also had higher levels of a protein called connexin 43. The All India Institute of Medical Science (AIIMS) in 205 for the first time used a robot to inject stem cells into human heart
• ischemia-reperfusion-induced acute renal failure (ARF) (40-min bilateral renal pedicle clamping) : administration of multipotent MSC to anesthetized rats could improve the outcome through amelioration of inflammatory, vascular, and apoptotic/necrotic manifestations of ischemic kidney injury. Accordingly, intracarotid administration of MSC (approximately 10⁶/animal) either immediately or 24 h after renal ischemia resulted in significantly improved renal function, higher proliferative and lower apoptotic indexes, as well as lower renal injury and unchanged leukocyte infiltration scores. Such renoprotection was not obtained with syngeneic fibroblasts. Using in vivo 2-photon laser confocal microscopy, fluorescence-labeled MSC were detected early after injection in glomeruli, and low numbers attached at microvasculature sites. However, within 3 days of administration, none of the administered MSC had differentiated into a tubular or endothelial cell phenotype. At 24 h after injury, expression of proinflammatory cytokines IL-1b, TNF-a, IFN-g, and inducible nitric oxide synthase was significantly reduced and that of anti-inflammatory IL-10 and bFGF, TGF-a, and Bcl-2 was highly upregulated in treated kidneys. The early, highly significant renoprotection obtained with MSC is of considerable therapeutic promise for the cell-based management of clinical ARF. The beneficial effects of MSC are primarily mediated via complex paracrine actions and not by their differentiation into target cells, which, as such, appears to be a more protracted response that may become important in late-stage organ repair^ref.
• autologous MSC transplantation in stroke patients^ref
• EPCs : injecting EPCs into the pulmonary circulation of rats results in microvasculature regeneration, a process that might translate into therapy for pulmonary arterial hypertension (PAH)
• NSCs :
• are easy to administer
• often by intracerebroventricular injections
• in faetal brain, they gain access to most of the subventricular germinal zone (SVZ), as well as to networks of cerebral vasculature, along the surface of which they would also migrate
• in adult brain, they integrate into the SVZ and migrate long distances, eg to the olfactory bulb, where they differentiate into interneurons, and occasionally
• circumvent the blood-brain barrier (BBB)
• are readily engraftable and no preconditioning regimen is required (e.g. no total body irradiation (TBI)) : human neural stem cells (HNSCs), injected into the lateral ventricle of 24-month-old rats after in vitro expansion, displayed extensive and positional incorporation into the aged host brain with improvement of cognitive score assessed by the Morris water maze after 4 weeks of the transplantation, suggesting that the aged brain is capable of providing the necessary environment for HNSCs to retain their pluripotent status^ref. One major hurdle would be to downregulate the production of amyloid precursor protein in the brain before transplanting stem cells as the protein has some physiological function in the normal brain^ref. Then researchers could work toward using stem cells to replace the basal forebrain cholinergic cells that are the first to die in Alzheimer's. It would be easy to replace the intramural cells in the cortex that degenerate in Alzheimer's with stem cells.
• develop into multiple cell types in the same region, but never  give rise to cell types inappropriate to the brain or yield neoplasm.
• develop into integral cytoarchitecture components
• are spontaneously attracted by apoptotic regions in the young as well as in the aged => the ideal solution for widely disseminated neurologic disorders.
• they are more resistant to toxic effect of metabolytes
• are immuno-privileged and hence are not rejected, on the contrary of differentiated neurons
• genes associated with neurodegenerative diseases are normally expressed throughout neural development and are essential for the elaboration and maintenance of neuronal subpopulations. The proteins they code for interact with numerous other cellular proteins that are components of signaling pathways involved in patterning of the neural tube and in regional specification of neuronal subtypes. Further, pathogenetic mutations of these genes can cause progressive, sublethal alterations in the cellular homeostasis of evolving regional neuronal subpopulations, culminating in late-onset cell death from normally non-lethal environmental stressors. Therefore, as a consequence of the disease mutations, targeted cell populations may retain molecular traces of abnormal interactions with disease-associated proteins by exhibiting changes in a spectrum of normal cellular functions and enhanced vulnerability to a host of environmental stressors. Neurodegenerative diseases may, therefore, represent an emerging class of developmental disorders characterized by novel biological responses to subthreshold neurodevelopmental abnormalities that impair targeted neuronal biosynthetic pathways without causing obvious developmental deficits. This developmental model of pathogenesis predicts that it will soon be possible to identify these dysfunctional pathways within vulnerable neuronal precursors present in pre-symptomatic individuals prior to the occurrence of irreversible cellular injury, and to successfully intervene using innovative pharmacologic, gene and stem cell neuroprotective and neural regenerative strategies^{ref1, ref2}.
• OPCs : both fetal and adult OPC phenotypes mediated the extensive and robust myelination of congenitally dysmyelinated (leukodystrophy) host brain, although their differences suggested their use for different disease targets.
• CSC in (congestive) heart failure (CHF)
• bulge cells in adult mice generate all epithelial cell types within the intact follicle and hair during normal hair follicle cycling. After isolation, adult Krt1-15-EGFP⁺ cells reconstituted all components of the cutaneous epithelium and had a higher proliferative potential than Krt1-15-EGFP^- cells^ref
• autologous myoblasts in (congestive) heart failure (CHF) : phenotypic switch towards slow-twitch fibres allows to sustain a cardiac workload over time.
• adipose tissue-derived regenerative cells infused 48 hours after myocardial infarction induced by balloon occlusion of the mid left anterior descending artery into coronary circulation without cell culture improved left ventricular ejection fraction (LVEF) at 6-months post-infarction in 13 swines (source : MacroPore Biosurgery, Inc.)
• type I diabetes mellitus (IDDM) : in NOD mice islet and ductal epithelial cells can regenerate from both splenocytes and endogenous stem cells, but regenerate faster from splenocytes
• autologous adipose stromal cells (ASCs) that secrete angiogenic and antiapoptotic factors to increase angiogenesis or achieve cardiovascular protection. Nude mice with ischemic hindlimbs demonstrated marked perfusion improvement when treated with human ASCs (P<0.05)^ref
Cellular transplantation does have limitations :
• it might not be possible to improve the function of structurally complex organs, such as the kidney or lung
• might prove ineffective in diffuse diseases, such as myocarditis, amyloidosis and portal hypertension
• differentiated cells and stem cells from mature individuals have a limited proliferative potential and might therefore not be capable of repairing large masses of defective tissue
For these purposes choices are :
• tissue or solid organ transplant (SOT)
• organogenesis : the growing of organs de novo from a primitive cells or tissue or stem cells. If feasible, organogenesis can produce physiologically competent organs is not yet clear.
• ex vivo organogenesis : fetal mouse metanephric kidney tissue can be grown from primitive mesenchyme in culture. However, the nephrons in these organs lack the blood vessels needed for function and can be frown to a size of only a few millimetersin vitro
• in vivo organogenesis : fetal kidneys transplanted in the renal capsule or omentum of rats can undergo vascularization and might even exhibit some function. If the technical capability to allow organogenesis in a human existed, the growth process would presumably require a period of months, if not years, and therefore a temporary measure, such as xenotransplantation, would be needed for vital organs. As an alternative, an animal could be used as a temporary host for the developing organ.
Web resources :
• International Society for Cellular Therapy (ISCT) : committees and sub-committees
• cord blood
• gene therapy
• graft evaluation
• tumor evaluation
• flow cytometry
• mesenchymal/nonhematopoietic
• HSC transplantation
• regulatory affairs
• immunotherapy/dendritic cells
• educational
• ex vivo expansion
• member services
• publication
• LAB practices
• hematopoietic stem cells committee
• facility sanitization
• biological licensure applications
• release testing
• tumor cell evaluation committee
• Foundation for the Accreditation of Cellular Therapy (FACT)
• tissue or solid organ transplantations (SOT)

History : Alexis Carrel is known as the founding father of experimental organ transplantation because of his pioneering work with vascular techniques. The work of Carrel and Charles Guthrie described in The Transplantation of Veins and Organs served as the foundation of vascular surgery and organ transplantation. An organ perfusion system created by Carrel and Charles Lindbergh led to the development of cardiopulmonary bypass by John Gibbon, thus making open heart surgery a reality. Frank Mann studied renal and heart transplantation at the Mayo Clinic in the 1930s. Early transplantation attempts in humans, which began with transplantation of renal allografts in 1936, generally did not succeed until the discovery of immunogenetics and the implementation of immunosuppressive drugs. In 1984, the US Congress passed the National Transplant Act, which prohibited the sale of organs for transplantation. The nationwide sharing system known as the Organ Procurement and Transplantation Network, which was subsequently contracted to the United Network for Organ Sharing, maintains a nationwide registry of potential recipients and provides organs and tissues to more than 15,000 recipients annually. All organs are available without charge and shared based on need and a first-come, first-served basis
Knowledge of immunology led to the first successful kidney transplantation between identical twins, in 1954. In 1952, David Hume made early attempts at allografting the kidney from an unrelated donor and found that the kidney graft functioned well for a short period. One of their grafts survived several months, and Hume reasoned that chronic uremia likely suppressed the immune function of the recipient. Joseph E. Murray performed the first successful identical twin renal transplantation at Peter Bent Brigham Hospital in Boston. In 1959, this team performed the first successful fraternal twin transplantation. Despite massive irradiation of the host prior to transplantation, these attempts were largely unsuccessful. Nonetheless, their efforts set the stage for the evaluation of rejection and mechanisms to avoid it. Over the next 25-year period, discoveries in immunosuppression paved the way for attempts at manipulating the recipient's immune system. These research efforts eventually led to the discovery of lymphocyte function, the role of the thymus in the ontogeny of the immune system (1961), the delineation of the human MHC (1963), the distinction of the T- and B-lymphocyte subsets (1968), and the demonstration of the MHC-restricted nature of the adaptive immune response (1974). Initial attempts at controlling rejection began with experiments involving total body irradiation. The initial evidence came in 1958 from Paris, France, where Mathe, a hematologist, treated 6 Yugoslavians who were accidentally irradiated on a previous occasion. The bone marrow homografts in these patients were successful, which led the way for irradiation to be used in other organ transplantation. Unfortunately, for renal transplantation, irradiation alone led to dismal outcomes, with only 2 reported successes: a single case by Merrill in 1960 and another by Hamburger in 1962. Further efforts to avoid and control rejection of transplanted organs led to the investigations of medications. Robert Schwartz and William Dameshek showed that the drug 6-mercaptopurine could prevent rabbits from producing antibodies to foreign proteins. In 1961, Joseph Murray prescribed 6-mercaptopurine for the first time to a human kidney transplant recipient. The patient unfortunately died from drug toxicity. Roy Calne at the Peter Bent Brigham Hospital experimented with 6-mercaptopurine and its close relative azathioprine, after he had disappointing experience with total body irradiation. Azathioprine used alone was not very effective in human transplantation. Careful studies undertaken by Thomas E. Starzl in the early 1960s, while he was in Denver, demonstrated that a combination of corticosteroids and azathioprine led to much better success. The work of Thomas Starzl transformed clinical transplantation into a clinical service and ushered in the proliferation of transplantation programs in kidney transplantation worldwide. Cortisone had been discovered in 1936, as an adrenal gland steroid with immunosuppressive properties. Prednisone, a cortisone derivative, was used subsequently in cadaveric kidney transplant recipients. In 1964, David Hume noted that prednisone not only was useful in preventing graft failure in regular doses, but it was useful for reversing renal allograft rejection in larger doses. However, continued use of corticosteroids permanently alters normal immune function and produces other very serious adverse effects. In 1972, Swiss biochemist Jean-François Borel discovered cyclosporine in natural fungal byproducts. Cyclosporine improved graft rejection in animals by inhibiting T-lymphocyte activity. Roy Calne investigated the effects of cyclosporin in dogs with renal allografts and pigs with orthotopic heart grafts. His work proved that cyclosporine was a much better immunosuppressive agent than corticosteroids, azathioprine, or a combination of both. Calne also found that cyclosporine was nephrotoxic; work by other investigators on devising safe protocols for cyclosporine led to marked improvement not only in kidney transplantation, but also in successful transplantation of the lungs, heart, heart and lungs, pancreas, and liver. In the late 1970s, cyclosporine increased the 1-year survival rate of liver allografts from 18% to 68%. Although cyclosporine is generally associated with significant adverse effects, administration of small doses in a controlled protocol results in minimal adverse events. The cocktail approach, which combines cyclosporine with steroids and azathioprine, was found to be the most effective approach to immunosuppression for organ transplantation patients over the next 10-15 years. More recently, this combination has been replaced by regimens that include newer immunosuppressive agents. Tacrolimus has almost completely replaced cyclosporine in liver and pancreas transplantation, and it is used in 50% or more of kidney recipients around the world. Mycophenolate mofetil has largely replaced azathioprine in most organ transplantation procedures. Additional new immunosuppressive agents that have been approved include immunosuppressive antisera and immunosuppressive monoclonal antibodies. Furthermore, a number of new regimens are being explored that attempt steroid withdrawal or avoidance, or calcineurin inhibitor withdrawal or avoidance.
Epidemiology : in 2004, there were about 27,000 solid-organ transplantations in the United States — nearly 1600 more than there had been in 2003. Yet the demand for organs remains far greater than the supply. As of July 2005, there were about 89,000 people on waiting lists, the largest group (62,500 patients) awaiting kidneys^ref.
• face transplantation : in October 2005, Maria Siemionow and her team at the Cleveland Clinic became the first to receive approval from the institutional review board (IRB) of a U.S. hospital to proceed with plans to perform the experimental surgery. In London, plastic surgeon Peter Butler has also obtained permission from the Royal Free Hospital's research ethics committee to begin evaluating patients for the procedure. In France, a 38-year-old woman who had sustained a horrific dog bite is recovering after the world's first partial facial transplantation, performed in November 2005 by surgeons from Amiens and Lyon. Other groups in the United States and elsewhere are also hoping to embark on facial transplantation, including a surgeon in China who is reportedly considering such an operation for an 11-year-old girl who was disfigured by acid burns. Fictional treatment of the topic in books and movies, including the 1997 film Face/Off, has fueled the public's fascination with facial transplantation, prompting intense media coverage of the French case in 2005. But Siemionow and other physicians engaged in research on facial transplantation emphasize that, in reality, the procedure is far more complicated — surgically, immunologically, and psychologically — and the results more uncertain than its fictional portrayals suggest. Technically, it is very difficult, much more difficult than the hand. In addition, because nerves grow and heal slowly, sensation and mobility of the transplant, and thus the operation's technical success, cannot be fully assessed until 9 months or longer after the procedure. Immunologically, transplanted skin triggers fiercer rejection than any other organ or tissue, so facial transplant recipients will have to take immunosuppressants for life and undergo frequent medical monitoring. We hope that, facing a mirror, the patient will be able to identify completely with her new face, the French woman's plastic surgeon, Bernard Devauchelle, told the audience of physicians at the Tucson symposium, 7 weeks after the operation. She now seems to be waiting, like the Penseur of Rodin, for the time when she will be able to smile. Siemionow, whose submission to the Cleveland Clinic IRB represented the culmination of 20 years of research, said that she is not intent on becoming the first physician to perform a full facial transplantation.

Indications :
• patients who have been severely disfigured by burns or trauma and who have some functional impairment, such as an inability to close their eyes or mouth. Such patients often have badly scarred faces that look like multicolored, immobile masks; features such as noses, eyelids, or lips may be missing or misshapen. Siemionow is also looking for people who have stable personalities and strong family support networks, yet are unhappy enough with their present faces to accept experimental surgery and a lifelong drug regimen that carries substantial risks of complications, such as cancer, infection, and diabetes. There are thousands of severely disfigured people in the USA, many of them so socially isolated that they are invisible to the general public. She doesn't want to perform the surgery on people who are able to live relatively comfortably with a traditionally reconstructed face. Not every burn patient needs a face transplant. Our protocol is looking for the patients who have already exhausted all reconstructive options. The goal of surgery is to provide them with a normal, human-looking skin and give them back their faces.
There are additional requirements. Because Siemionow intends to transplant skin and subcutaneous tissue but not the underlying muscles, potential candidates will have to undergo electrophysiological testing of facial muscles to assess the degree of atrophy and evaluate how well their muscles may be able to "reanimate" the transplant. She explained that burn victims who are treated with partial-thickness skin grafts typically have progressive facial scarring that encases the underlying muscles, impairing their mobility, but that physical therapy can help to restore function. Potential candidates for a facial transplant must also have sufficient areas of intact skin elsewhere on their bodies to provide autologous grafts for a rescue operation, should the transplantation fail or the transplant be rejected. The area needed to cover an entire face, scalp, front of the neck, and ears is about 1200 cm² of skin. Such a requirement eliminates many people with severe facial burns, who have often already undergone dozens of skin-graft operations, initially to replace the lost skin and later to deal with the scarring that inevitably occurs. Moreover, any candidate who is chosen must be able to accept not only medical risks, uncertainty of success, and the likelihood of relentless media attention, but also the possibility that the operation may never take place at all: they may understand that they have to wait a little bit, but they may not understand that it may be eternity — if there is no donor, for example. Potential candidates who are invited to the Cleveland Clinic will have psychiatric interviews and psychological testing, will meet with an ethicist, and will go through a detailed informed-consent process. Because adherence to the immunosuppressive regimen will be crucial to the survival of the transplanted tissue, the Royal Free Hospital's Butler and psychologist Alex Clarke have used evidence from the transplantation literature to develop a compliance-screening tool that helps them assess potential candidates' personalities and predict their behavior as patients on the basis of their history and, in particular, how they adapted to their initial injury and its subsequent treatment. After the French transplantation, questions surfaced about the recipient's mental health when her daughter told reporters that the dog bite had occurred after she had taken an overdose of sleeping pills in an apparent suicide attempt. They would not probably have selected a patient with a previous suicide attempt unless it happened to be during a reactive depression, a self-terminating event. Dubernard said in January 2006 that his patient had resumed smoking while still hospitalized and recovering from her surgery, a habit that could compromise blood flow to the graft — and a behavior that Butler and Clarke's compliance-screening tool might have predicted. On the other hand, the patient had begun to go out in public and was gratified to find that her new face did not attract attention — suggesting that she was making progress incorporating her transformed countenance into her identity. The surgical justification for trying a facial transplantation is that the texture and pliability of facial skin are unique. Grafts using skin from elsewhere on the body or prosthetic materials are an unsatisfactory substitute: although they cover the bones and muscle, they don't look, feel, or move like a real face. In addition, efforts to reconstruct features such as lips or ears usually yield poor results. To be considered a success, transplantation would need to restore at least some facial mobility, imparting a degree of expression and function. A key question is whether the French partial transplantation or the full-face transplantations being planned by Siemionow and Butler will achieve that goal. Siemionow's approach is to harvest and transplant the entire facial flap and underlying subcutaneous tissue, along with its blood supply. She estimated that harvesting the flap from the donor will take 4 to 5 hours and that transplanting it will take 10 to 15 hours. 10 or more surgeons may participate in the dual operations. She plans to use major vessels in the neck — the external carotid arteries and external jugular veins — to connect the recipient's circulation to the graft. Once perfusion is established, several pairs of the recipient's sensory nerves would be connected to those in the transplanted tissue and to attach the transplanted skin flap to the underlying structures at the sites of various facial ligaments. Depending on the specific needs of the recipient, the graft may include lips, nose, or ears. However, both hope to avoid transplanting facial muscles. Skin can survive ischemia for up to 13 hours, whereas muscle can survive for only about 6 hours. To include muscles would prolong the operation to harvest the tissue, potentially increasing the duration of ischemia, and would also complicate the transplantation surgery itself, since some of the recipient's own facial muscles would probably have to be removed. Removing them, in turn, would make a later rescue operation much more difficult in the event of rejection. Moreover, transplanted muscles might not recover normal function. Chicago's Walton questions whether the proposed operation will work. He believes that it will be difficult to ensure an adequate blood supply to the graft without transplanting both the superficial and deep vessels that supply it. Such an approach would require also harvesting the superficial myoaponeurotic system, a myofascial layer lying between the vessels that contains the muscles of facial animation. If a graft that includes this layer is laid over the recipient's own facial muscles, how would the muscles in the patient's face be hooked up to the transplanted face? At best, you're going to have something that looks a little bizarre. What you hope is you don't end up with a mask. In the French operation, surgeons transplanted a triangle of tissue that included the lower part of the nose, the lips, and the chin, replacing tissue that had been destroyed as a result of the dog bite. The transplant contained skin, fat, and mucosa, as well as muscle groups that control the puckering and elevation of the lips. Surgeons attached the distal portions of some transplanted muscles to the proximal portions of the recipient's muscles. Although the woman's face looked impressively normal immediately after surgery, photographs taken in the weeks since have shown marked drooping of the lower lip. Basically, her lips are paralyzed. Hopefully, with the residual muscle that's hooked up to the transplant, she'll have some movement of the corners of her mouth.  The question of how the transplanted face will look is critical not only to the recipient, but also to the relatives of potential donors. You would want to be sure that the family understands that the appearance of their loved one will not at all be replicated. A software program developed by forensic anthropologists has been used to demonstrate to British transplantation coordinators that the new face will combine aspects of the donor and the recipient, with the underlying skeleton and muscles largely determining its shape and final appearance. You don't get donor identity transplant, you don't get quite back to where you were. It's a hybrid

The approximate sites on each side of the neck are indicated, where the recipient's external carotid artery and external jugular vein would be anastomosed with the corresponding vessels in the graft. The supraorbital nerve, infraorbital nerve, and mental nerve on each side would be connected with the corresponding nerves in the transplanted tissue in order to provide sensation to the grafted skin.
Finding donors may be the rate-limiting step in facial transplantation. In Cleveland, Siemionow plans to identify a candidate first, then work with the local organ-procurement agency to try to find a donor with a compatible blood group who matches the recipient's sex, race, and approximate age. Matching of HLA antigens will probably not be possible, although the French donor was a partial HLA match for the recipient. In France, unlike in the USA, the law presumes consent for organ donation, but French surgeons nonetheless obtained the consent of the donor's family, and the donor's face was reconstructed afterward with the use of a silicone prosthesis. In Louisville, Kentucky, where the only 2 U.S. hand transplantations have been performed, difficulty in finding donors has been a principal reason why additional ones have not been done. Although 2 groups of surgeons in the city are eager to perform face transplantations, Paul O'Flynn, executive director of Kentucky Organ Donor Affiliates, anticipates that finding donors will be challenging. Of the 25,000 people who die in Kentucky hospitals each year, only about 200 are potential organ donors, because donors must be brain-dead and on a ventilator and must fulfill other criteria, such as not having cancer or various infections. Only about half of these potential donors' families consent to donation. The pool of potential tissue donors is smaller still, and obtaining consent for a facial transplantation is more problematic than for other tissues. I have not laid the groundwork for approaching families about a face transplant. For a transplant recipient, the primary long-term medical risks associated with the procedure are posed by the drugs needed to suppress the immune system and prevent rejection. Research in the field currently focuses on finding treatments that will induce specific tolerance to the transplanted tissue, with the goal of reducing or eliminating the need for such drugs. For example, Dubernard twice transfused his patient with hematopoietic stem cells from the facial-tissue donor 4 and 11 days after transplantation surgery, hoping to induce tolerance; still, she had a serious episode of acute rejection about 3 weeks after the operation, which was treated with high doses of corticosteroids. As short-term induction therapy after transplantation, Siemionow plans to use antithymocyte globulin or specific antibodies against the TcR complex — treatments that target T cells and help reduce the risk of acute rejection. The recipient will probably take tacrolimus, prednisone, and mycophenolate mofetil to maintain immunosuppression. Such a regimen costs between $12,000 and $24,000 per year and is associated with an increased incidence of infections, diabetes, cancer (especially squamous-cell carcinoma and lymphoma), renal and hepatic toxic effects, hypertension, disturbances in blood lipid levels, and other side effects^ref. A report published in 2004 by England's Royal College of Surgeons estimates that graft loss due to acute rejection might occur in approximately 10% of recipients within the first year and that substantial loss of graft function from chronic rejection might be expected in 30-50% of patients during the first 2-5 years^ref. The report concluded that current information on the risks of facial transplantation was inadequate with respect to informed consent and recommended that further research be done before full-face transplantation was attempted. The French National Ethics Committee and the American Society for Reconstructive Microsurgery (ASRM) have issued similar recommendations regarding full-face transplantation. However, in January, recognizing that some U.S. groups are moving forward, the ASRM and the American Society of Plastic Surgeons jointly issued a set of guiding principles, urging that facial transplantation be attempted only by multidisciplinary teams under IRB-approved research protocols and only in patients who cannot be helped by traditional reconstructive surgery^ref. Those in the best position to accurately balance the risks and benefits of facial transplantation are the severely disfigured patients who are appropriate candidates — and that they deserve the opportunity to do so
• lymphoid transplantation : stromal cells play an important role in the formation of the normal organized microarchitecture of secondary lymphoid organs. A tissue-engineered, lymphoid tissue–like organoid, which was constructed by transplantation of stromal cells embedded in biocompatible scaffolds into the renal subcapsular space in mice, had an organized tissue structure similar to secondary lymphoid organs. This organoid contained compartmentalized B-cell and T-cell clusters, high endothelial venule-like vessels, germinal centers and follicular dendritic cell networks. Furthermore, the organoid was transplantable to naive normal or severe combined immunodeficiency (SCID) mice, and antigen-specific, IgG-isotype antibody formation could be induced soon after intravenous administration of the antigen. This simplified system of lymphoid tissue–like organoid construction will facilitate analyses of cell-cell interactions required for development of secondary lymphoid organs and efficient induction of adaptive immune responses, and may have possible applications in the treatment of immune deficiency^ref.
• thymus transplantation : discarded thymus tissue from infants 2 to 35 days old who were undergoing corrective heart surgery after we received informed consent from the donors' parents. Down's syndrome was a criterion for exclusion of donors. Preparation of the thymus tissue for transplantation has been described elsewhere^ref. A Stadie–Riggs hand microtome (Thomas Scientific, Swedesboro, N.J.) was used to slice the thymus tissue^ref. The slices of thymus tissue were inserted into the quadriceps bilaterally in an open procedure in the operating room^{ref1, ref2}

Indications : DiGeorge syndrome (DGS) / velocardiofacial syndrome (VCFS)
• larynx transplantation : an early attempt to treat laryngeal cancer with a partial laryngeal transplant^ref was accompanied by rapid recurrence of the tumor, an outcome that quashed interest in the procedure for nearly 2 decades. Similarly, tracheal transplantation has had only limited success^{ref1, ref2}. In 1987, the Cleveland Clinic Foundation initiated a program to explore the potential of laryngeal transplantation. The program addressed four issues critical to successful transplantation: revascularization, reinnervation, rejection, and the ethics of transplanting an organ considered by some to be nonvital. In rats, the rate of success of laryngeal transplantation was nearly 100%^{ref1, ref2}. In these studies in animals, we classified the histologic features of laryngeal rejection^ref; determined the maximal tolerable period of ischemia; evaluated preservative solutions^ref; determined doses of cyclosporine^ref, prednisone, and adjunct in vitro radiation^ref; and studied the use of sirolimus and tacrolimus (Strome M, Wu J, Jalisi H, Strome S. Laryngeal transplantation: a systematic approach to establish efficacy. In: Fried MP, ed. The larynx: a multidisciplinary approach. 2nd ed. St. Louis: Mosby–Year Book, 1996:625-9). In 1998, we performed a total laryngeal transplantation in a man who had sustained a severe traumatic injury to the larynx and pharynx. a 40-year-old man who had been in a motorcycle accident 20 years earlier. His larynx and pharynx had been crushed, leaving him aphonic. He lost his sense of smell and taste a year after the injury. He used an external device (Cooper-Rand Electrolarynx) to speak. Despite attempts at another institution to reconstruct his larynx, it was totally stenotic and shortened, with immobile arytenoid cartilages and a fragmented cricoid cartilage^ref. The donor, a 40-year-old man who had died from a ruptured cerebral aneurysm, had had no coexisting illnesses and had not smoked. Serologic tests for CMV and EBV were negative. HLA matching between the donor and the recipient was complete. The donor had been intubated for less than 48 hours before his death. The tissues obtained from the donor, including 6 tracheal rings, the thyroid gland, the pharynx, the larynx, both superior laryngeal nerves, both superior thyroid arteries, both recurrent laryngeal nerves, a segment of the right jugular vein with contributions from the larynx and the pharynx, and the middle thyroid vein. The upper right panel shows the tissues removed from the patient (purple areas). The thyroid gland was split in the midline and retracted laterally. The lower left panel shows the pharynx and upper esophagus of the transplant split posteriorly in the midline, with the right superior thyroid artery anastomosed to that of the patient and the right jugular vein anastomosed to the patient's right common facial vein. The lower right panel shows the donor tissues after transplantation in the patient. The tracheal stoma is permanent and self-sustaining. Three circumferential sutures secure the thyroid cartilage to the hyoid bone, elevating the larynx. The midline suture also includes the epiglottis and pulls it anteriorly. Both superior thyroid arteries and superior laryngeal nerves are juxtaposed. The transplanted left middle thyroid is anastomosed in an end-to-side fashion to the patient's left jugular vein. The duration of cold ischemia was 10 hours, well within the acceptable 20-hour window^ref.5 On the third postoperative day, the patient uttered his first laryngeal speech in 20 years (the word "hello") and the transplant has remained viable for 40 months^ref.


Several details of this unique case deserve emphasis. The patient's larynx had been destroyed by trauma, not cancer. There was complete HLA matching between the donor and the recipient. Laryngeal transplantation is not a lifesaving procedure, so there was no urgency to perform it. This circumstance permitted the authors the luxury of waiting for an HLA-identical donor — a distinct advantage that minimized the chance of rejection and that obviated the requirement for excessive immunosuppression. The surgical procedure itself, though challenging, was surprisingly straightforward. Several technical points deserve mention: the ability to establish perfusion of the donor's organ before removal of the recipient's larynx, the ability to transplant a large portion of the pharynx, and the surprising completeness of the reinnervation of both vocal cords, even though continuity of the left recurrent laryngeal nerve could not be established surgically. Furthermore, the donor tissue was a composite allograft, composed of the larynx, a substantial portion of the pharynx, the thyroid gland, and the parathyroid glands. The episode of rejection after the procedure was also straightforward: the patient presented with a physiologic aberration (a change in his voice) and swelling of the graft (laryngeal edema), which was confirmed by biopsy of the tracheal mucosa. The ability to detect rejection early bodes well for the treatment of rejection in patients who receive this type of transplant. In this patient, the restoration of a normal voice and the rehabilitation to an occupation totally dependent on a speaking voice are remarkable^ref.
Indications :
• aphonic patients with laryngeal trauma
• patients with large benign chondromas requiring laryngectomy
• patients who have undergone laryngectomy for cancer and who remain disease-free after 5 years.
• tooth transplantation : transfer of a tooth from one socket to another, either in the same or a different person.
• tongue transplantation : it is used after glossectomy for oral cavity cancers. Patients won't regain their sense of taste, but with their new tongue they will regain some feeling and be able to eat and talk normally.
• heart transplantation

History : in 1905, Carrel and Guthrie performed the first cardiac transplantation in animals at the University of Chicago. This was a heterotopic experimental transplantation. Parts of a small dog were transplanted into the neck of a larger dog by anastomosing the cut ends of the jugular vein and carotid artery to the aorta, the pulmonary artery, one of the vena cavae, and the pulmonary vein. In 1933, Mann, Wu and Williamson transplanted a canine heart into the carotid-jugular circulation with establishment of coronary perfusion at Mayo Clinics. The longest survival was 8 days, and he observed evidence of allograft rejection as the heart was infiltrated with lymphocytes, mononuclear cells, and polymorphonuclear cells. The work of Marcus and colleagues at Chicago Medical School contributed to donor graft preservation and improved coronary perfusion techniques. Vladimir Demikhov's research greatly advanced the field of experimental cardiac transplantation. His published works documented many experiments, including transplantation of the head, transplantation of halves of the body, and surgical combination of 2 animals with the creation of single circulation. His initial work in cardiac transplantation involved canine heterotopic cardiac transplants to the inguinal region. His monograph reported a long series of 250 experimental efforts at transplanting a heterotopic intrathoracic cardiac graft. On June 30, 1946, Demikhov transplanted a heterotopic heart and lung; the animal survived for 9 hours and 26 minutes. A subsequent experiment on a dog resulted in 25 days of survival, and the cause of death was probably dehiscence of the tracheobronchial suture line. Experiments in orthotopic transplantation began with Demikhov, who attempted to maintain donor and recipient perfusion during anastomosis. Problems associated with maintaining the recipient during transfer and preserving the graft were addressed by Neptune and colleagues. Neptune's team transplanted the entire heart-lung block and maintained both the donor and recipient in a cooler to maintain hypothermia. Webb and Howard demonstrated that canine hearts that were heparinized and flushed in potassium citrate could survive prolonged periods at low temperature. When transplanted heterotopically, the function of these organs returned. Webb and Howard also performed successful orthotopic heart-lung transplantations in which the recipient was maintained with cardiopulmonary bypass during transfer. In 1958, Goldberg and colleagues at the University of Maryland performed orthotopic cardiac transplantations using an innovative technique in which the left auricle was anastomosed with the left atrium. This circumvented the problems associated with anastomoses of individual pulmonary veins. This technique was further refined by Cass and Brock, who used right and left atrial cuffs. In 1960, Richard Lower and Norman Shumway described the modern surgical technique of orthotopic cardiac transplantation. The recipient was kept alive on cardiopulmonary bypass; the donor heart was immersed in cold saline; and anastomoses were performed to the atria, pulmonary artery, and aorta. The dogs that underwent transplantation survived and resumed their regular activity; this generated an immense interest in cardiac transplantation and further experimental work by other investigators, including D.A. Blumenstock, who in 1963 reported that 50 of his dogs survived for periods ranging from 1-42 days. Deaths in these dogs occurred secondary to acute rejection. Subsequent investigators used immunosuppression and improved long-term survival; the immunosuppressive drugs used included steroids, cyclosporine, and azathioprine. By the mid 1960s, surgical techniques, methods of recipient support, and methods of myocardial protection had been described. In addition, transplant allograft rejection had been reported, and methods of diagnosing and treating rejection were available. Legal and logistic issues were the next hurdles that prevented heart transplantation in humans. On December 3, 1967, the first successful human cardiac transplantation was performed by Christiaan Barnard at Groote Schuur Hospital in Cape Town, South Africa. The transplant recipient was a 54-year-old man with end-stage ischemic heart disease; the donor was a young man with a severe brain injury. The recipient initially recovered but subsequently died of Pseudomonas pneumonia 18 days later. On December 6, 1967, Adrian Kantrowitz performed a transplantation from an anencephalic infant to an 18-month-old child using deep hypothermia and circulatory arrest. Although the surgery went well, postoperatively, the recipient developed metabolic and respiratory acidosis, leading to cardiac arrest, and survived only 6.5 hours. The autopsy showed diffuse atelectasis of both lungs. After multiple attempts at cardiac transplantation in the late 1960s, poor outcomes were achieved and interest in this procedure waned. However, during the 1970s, an organized approach to cardiac transplantation (mostly by the group at Stanford University) improved the 1-year survival rate from 22% in 1968 to 65% in 1978. This success occurred because of improved management of infectious complications, better donor and recipient selection, and improved capabilities of diagnosing and aggressively treating rejection. The widespread adoption of cyclosporine use in the 1980s resulted in increased worldwide enthusiasm for cardiac transplantation and much-improved long-term survival. Denton Cooley performed the first clinical heart-lung transplantation on September 15, 1968. The team replaced the heart and lungs of a 2-month-old infant who had an atrioventricular canal defect with the heart and lungs of an anencephalic infant donor; the recipient survived only 14 hours, succumbing to respiratory failure. In 1982, Bruce A. Reitz published the first successful clinical series of heart-lung transplantations; the use of cyclosporine and the Stanford University's group experience with experimental cardiopulmonary transplantation were important contributing factors^{ref1, ref2, ref3, ref4, ref5, ref6, ref7, ref8}.
If the donor dies with myocarditis or other kind of systemic infection, only valves can be used for transplantation.
Epidemiology :
• USA : every year about 2,200 patients with end-stage heart failure receive heart transplants. Yet 400,000 or more individuals develop heart failure annually, of whom 30,000 to 100,000 potentially could benefit from a transplant, but 700 dies while waiting the transplant. Many patients have to be rejected because of advanced age, other medical conditions that limit life expectancy or quality of life, poor medical compliance, or bad habits such as smoking or alcohol abuse
• Italy : about 200 transplants annually
Indications : dilated cardiomyopathy and ischemic cardiomyopathy
• CI < 2.0-2.5 l/min/m²
• LVEF < 20-25%
• V_{O2 max} < 14 ml/kg/min
Contraindications :
• hemodynamic : high pulmonary vascular resistances (transpulmonary gradient = MPAP - PCWP > 12 mmHg or transpulmonary gradient/CO > 2 Wood units (WU) : if 2-6 WU alternatives are transplant from a oversized donor or domino (crossover)-transplant; if > 6 WU combined heart-lung trasnplantation or LVAD)
• extracardiac :
• neoplasm not cured clinically
• systemic or regional infections
• systemic vasculopathies
• recent pulmonary infarctions
• ulcerative diseases of the digestive apparatus
• severe hepatopathy or nephropathy : eventually liver and kidney transplants can be combined
• uncompensated diabetes mellitus or TOD
• psychosocial conditions preventing adhesion to immunosuppressive therapy
• every life-threatening disease
Donors :
• allogeneic heart transplantation / cardiac allograft : the donor (usually aged < 35 years) should have good contractile function at echocardiogram, lack of major EKG alterations, an inotropic support < 10 mg/kg/min of dobutamine or equivalent, lack of sepsis, trauma or coronary lesions, lack of prolonged systemic arterial hypotension or cardiac arrest
• heart xenotransplant
Transplant : the recipient is usually aged < 55 years
• orthotopic heart transplantation (OHT) : the native heart is removed
• heterotopic heart transplantation : the native heart is maintained and the donor heart is placed in parallel in the right pleural cavity. Used when pulmonary vascular resistances are high or when the donor body is smaller than the recipient's one. Other models are used in animals. The atria are anastomised in parallel : the recipient left atrium is incised along Waterston's groove and sutured to the donor's one. The right atria are anastomised between them using the donor's vena cava. The donor aorta is anastomised end-to-side to the recipient one, while the connection of the 2 pulmonary arteries requires a prosthetic tube or homograft.


The requirement for ABO compatibility in heart transplantation is not applicable to infants. ABO-incompatible heart transplantation during infancy results in development of B-cell tolerance to donor blood group A and B antigens. This mimics animal models of neonatal tolerance and indicates that the human infant is susceptible to intentional tolerance induction. Tolerance in this setting occurs by elimination of donor-reactive B lymphocytes and may be dependent upon persistence of some degree of antigen expression. Intentional exposure to nonself A and B antigens may prolong the window of opportunity for ABO-incompatible transplantation, and have profound implications for clinical research on tolerance induction to T-independent antigens relevant to xenotransplantation^ref.
While awaiting for LTx, patients can be treated with VAD or TAH.
Technique :
• explant : the ascending aorta is clamped transversally and cardioplegic solution is infused in the aortic bulb => rapid resection of superior and inferior cava veins, pulmonary veins (at emergence from pericardial cavity), pulmonary arteries and ascending aorta at the level of aortic arch. For heterotopic transplant a longer tract of superior vena cava and ascending aorta is explanted. If lungs are explanted separately, the trunk of pulmonary artery is resected and the pulmonary veins are left intact by sectioning the left atrium. The explantation of the heart-lung block is performed by sectioning aorta, cava veins and trachea.
• native cardiectomy : cannulation of ascending aorta, superior and inferior cava veins as distally as possible from right atrium. Snaring around cannulas occludes cava veins, while ascending aorta is clamped. Cardioplegic solution is administed only for domino transplantation. The right atrium is incised along the atrioventricular junction and continued posteriorly along the coronary sinus. The ascending aorta and the trunk of pulmonary artery are sectioned transversally. The removal of ventricular block is completed by sectioning the interatrial septum and the left atrium along the atrioventricular junction. The atrial cuffs are left in situ to perform the so-called classic technique.
• transplant :



• Lower-Shumway classic technique (4 sutures) : the donor's heart is prepared by ligating the superior vena cava and incising the right and left atria to adapt them to the atrial cuffs of the recipient. The left atria are then sutured beginning from the angle correspoding to the left superior pulmonary vein and the same thread is used to suture the right atria. Then the 2 ends of the pulmonary artery and aortas are sutured
• bicaval technique : almost full removal of the recipient right atrium, leaving only 2 ribs around the orifices of the cava veins to which the donor right atrium is sutured. Advantages : better containment of tricuspid valve, sinusal rhytm restart and atrial systole effectiveness


The lymphatic circulation is closed and the innervation is removed =>
• loss of ortho- and parasympathetic stimuli, so heart is responsive only to circulating catecholamines, so compensations are slower than usual
• loss of sensitive innervation => lack of angina pectoris => IHD is monitored by coronarography
Perioperatory therapy : high-dose corticosteroids and antibodies for 1-2 weeks
Maintenance therapy (lifetime) : cyclosporine (275-375 ng/ml in induction => 150-250 ng/ml) + azathioprine + prednisone
Complications : 30-day mortality = 8%; 1-yr OS = 85%; 5-yr OS = 70-80%; 10-yr OS = 50-60%
• immediate complications : graft failure due to poor preservation or high pulmonary vascular resistances
• short-term complications :
• infections (40% has a major infection and 80% a minor infection within 1 year)
• Toxoplasma gondii retinochoroiditis in mismatched transplants (positive donor and negative recipient)
• acute rejection : Working Formulation staging after endomyocardial biopsy (routinely performed every week during the first month, then biweekly and finally monthly for the first year)
• 0 : no rejection; neither cellular infiltrate nor myocyte damage
• 1 : perivascular and/or interstitial lympho-monocyte infiltration without myocyte damage
• 1a : focal perivascular and/or interstitial lympho-monocyte infiltration without myocyte damage
• 1b : diffuse perivascular and/or interstitial lympho-monocyte infiltration without myocyte damage
• 2 : lympho-monocyte infiltration with focal myocyte damage
• 3a : lympho-monocyte infiltration with multifocal myocyte damage
• 3b : lympho-monocyte infiltration with diffuse myocyte damage
• 4 : diffuse polymorphic infiltration with myocyte damage, edema, hemorrhage and vasculitis
Therapy : high-dose corticosteroids and antibodies; tacrolimus can be scaled up, plasmapheresis (irradiation is no longer used)
• long-term complications :
• cardiac allograft vasculopathy is the most common cause of death and retransplantation following heart transplantation, and about 10% of patients per year have evidence of accelerated vascular disease; 20-50% at 5 years, usually asymptomatic due to cardiac denervation. It is differentiated from atherosclerosis by concentric thickening without lipid core and for involvement of the whole coronary tree. Intracoronary echography is more diagnostic than coronarography.
• adenovirus
• enterovirus
• parvovirus
• HHV-1 / HSV-1
• HHV-5 / CMV
• myocardial fibrosis due to repeated acute rejections, chronic rejection, chronic allograft vasculopathy, may lead to congestive heart failure and require retransplantation
• tumors : 10% within 5 years (mostly skin cancer, and lymphomas (15%)). Multivariate analysis showed no significant increase in the incidence of cancer with recipient age, sex, number of rejection episodes, the type of immunosuppression or the use of RATG. Patients receiving RATG developed their malignancies significantly earlier after transplantation and succumbed faster after the diagnosis. Cancer is a limiting event for long-term survival after heart transplantation. No individual risk factors allow predicting its development. In the present cohort, RATG does not have carcinogenic effects following transplantation, but is associated with a more precocious development of malignancies^ref
• metabolic complications due to immunosuppressors : chronic renal failure (2% within 5 years), diabetes mellitus, systemic arterial hypertension, dyslipidemia, osteoporosis, hyperuricemia
90% has a good QOL; periodic coronarographies after 1 year. Life-long immunosuppressors are measured in plasma every 3-6 months
Web resources : International Society for Heart and Lung Transplantation (ISHLT)
• lung transplantation

History : experiments in lung transplantation were underway during the 1940s, long before human heart transplantation became a reality.
• In May of 1947, Demikhov performed the first canine transplantation of the lungs alone
• In November, 1947, Demikhov reported a successful transplantation of the lower lobe in a dog, which survived 7 days
• Juvenelle performed early experiments in autografting and reimplantation
• Neptune and colleagues began to use the atrial cuff method for anastomosis. With proper atrial cuff anastomosis, pulmonary hypertension, which was observed in earlier experimentation as part of the reimplantation response, could be avoided. Bronchial dehiscence plagued Demikhov's experiments in 1947. Haglin developed a method for reestablishing the bronchial circulation by vascular anastomosis. The Toronto Lung Transplant Group used a technique of omentopexy to reinforce the bronchial anastomosis. Subsequently, telescoping the bronchial anastomosis to a depth of one cartilaginous ring was shown to be equally effective, and thus omentopexy became unnecessary. Additional advances occurred in the area of lung preservation; these methods were crucial for successful transplantation. Initial techniques included hypothermia and flush perfusion of the pulmonary vasculature in the unventilated lung. The positive index inspiratory pressure during the procurement procedure increases interalveolar surfactant, which minimizes pulmonary complications in the graft. Insufflating the lung with 100% oxygen during procurement coupled with the administration of prostacyclin into the pulmonary circulation has resulted in acceptable graft function after 6-8 hours of ischemic time.
• 1950 : Metras performs lung allografts in mongrel dogs and inbred beagles in Marseilles, France
• 1954  : Hardin and Kittle performs single lung allotransplant with a technique similar to the current one
• Blumenstock in Cooperstown, NY performs lung allografts in mongrel dogs and inbred beagles. Thomas and Blumenstock experimented with immunosuppressive regimens to combat lung transplant rejection. A 300-day survival in a lung allograft recipient was achieved with the help of immunosuppressive agents. Another hurdle that needed to be overcome concerned the healing of tracheal and bronchial anastomoses. The Toronto Lung Transplant Group demonstrated that better immunosuppression with cyclosporine led to improved healing of the bronchial anastomosis.
• James D. Hardy and his team performed the first single-lung transplantation in a human at the University of Mississippi Medical Center on June 11, 1963. A 58-year-old captive man condemned to capital death with unresectable left lung cancer and obstructive pneumonitis (severe emphysema) was the recipient. The donor was a patient who died from a massive myocardial infarction. The lung transplant recipient received immunosuppression with azathioprine and irradiation. Unfortunately, the patient died on the 8th (18th?) postoperative day because of progressive renal failure despite peritoneal dialysis. However, at autopsy, the vascular and bronchial anastomoses were intact and evidence of rejection in the transplanted lung was absent.
• Fritz Derom of the University of Ghent in Belgium transplanted a lung in the 1960s into a recipient who had end-stage respiratory failure due to silicosis. The patient improved significantly and lived for 10.5 months after the operation. This group of investigators from Ghent was the first to successfully treat and reverse episodes of rejection and acquired infectious complications in the recipient. The growth of lung transplantation was slow due to unclear eligibility criteria for lung transplant recipients, and, despite clear improvement in function after transplantation, survival benefits were less clear. In fact, at least one study showed patients with end-stage lung disease survived longer than transplant recipients.
• By 1978, 38 human lung transplantations had been performed. Bronchial disruption and the inability to differentiate infection from rejection appeared to be the major problems. Improved healing of the bronchial anastomosis was found after the introduction of cyclosporine, and this may have been due in part to the lower routine doses of corticosteroids. Lessons were learned from en bloc heart-lung transplantation, in which single distal tracheal anastomosis and maintenance of collateral circulation to the airway achieved much better anastomotic healing. Limiting the length of the donor bronchus and extrinsic revascularization by wrapping the anastomosis with omentum led to advancements in anastomotic techniques.
• This culminated in a successful single-lung transplantation, a procedure pioneered by the Toronto Lung Transplant Group under the leadership of Joel Cooper and Griffith Pearson.
• Subsequently, lung transplantation was performed by G.J Magovern and A.J Yates at the University of Pittsburgh; this patient survived only a short time.
• 1983 : the Toronto Lung Transplant Group consisting of Joel Cooper, Griffith Pearson, and Patterson accomplished long-term survival following a successful single-lung transplantation : isolated single-lung transplantation was performed for patients with end-stage COPD and advanced pulmonary fibrosis, who died after 6.5 years from renal failure
• 1990 : Pasque and Joel Cooper perform bilateral sequential single-lung transplantation (ie, isolated double-lung transplantation) for patients with bronchiectasis and cystic fibrosis. Over time, bilateral sequential single-lung transplantation became the procedure of choice because en bloc double-lung (and heart) transplantation was a procedure of considerable technical complexity.
• More recently, use of living donors for lobar allografts has been demonstrated to be a useful alternative for selected patients who require isolated lung transplantation.
It has to be practiced within 12 hrs from explant : assisted ventilation and forced blood circulation damage 80% of donors' lungs. There's no time to practice compatibility tests (usually only blood groups are typized) => high probability of rejection.
Indications :
• chronic obstructive pulmonary diseases (30%) : emphysema +/- a₁-antitrypsin deficiency (15%) with FEV₁ < 30%, P_aO2 < 55-60 mmHg at rest => single lung tranplantation is contraindicated if donor's lung is too small (the hyperinflation of the remaining native recipient's lung could prevent its ventilation, reducing functional reserve in chronic rejection), while bilateral lung transplantation is technically more demanding, so single lung is indicated for elderly patients with higher risk, previous surgery to hemithorax or pleurodesis, or patients with significative asymmetry in bullae distribution or pulmonary function. Bilateral transplant is preferred in younger patients with diffuse bullae in both lungs and severe bronchitic components. Bilateral transplant allow use of undersized donor lungs. Effort tolerance is similar and even in single lung transplant many patients achieve FEV1 > 50%.
• restrictive diseases : idiopathic pulmonary fibrosis (15%) and all kinds of interstitial lung diseases with TLC < 60%, P_aO2 < 55-60 mmHg at rest and secondary pulmonary arterial hypertension. Single lung transplantation is recommended (neither adhesions nor septic complications), but perfusion and ventilation can shift to the transplanted lung causing a reperfusion  edema-like syndrome. Bilateral transplant is indicated only for secondary bronchiectasis to minimize infection risk.
• dysplastic diseases with chronic infections (15-20%) : cystic fibrosis and bronchiectasis with FEV₁ < 30%, P_aO2 < 55-60 mmHg at rest. Mortality in waiting list = 20%. Bilateral transplantation is mandatory and care should be used to prevent pleural infections. Lobar living-donor or cadaver lung transplant is used in pediatric recipients.
• diseases associated with pulmonary arterial hypertension : primary (10-15%) and secondary pulmonary arterial hypertension with mean RAP > 10 mmHg, mean PAP > 50 mmHg, CI < 2.5 l/min/m² and NYHA class III/IV, only when the cardiac defect can be corrected. Bilateral lung transplant from undersized donors is recommended due to cardiomegaly
Inclusion criteria :
• chronic irreversible pulmonary disease
• ineffective medical therapy
• oxygen-dependance and limitation of activity
• reduced life expectancy
• possibility of rehabilitation
• lack of significative coronary artery disease
• adequate psychosocial and nutritional status
Exclusion criteria :
• age > 65 years
• active pulmonary and extrapulmonary infections other than due to cystic fibrosis and bronchiectasis
• systemic diseases with lung involvement
• other associated diseases (hepatopathies, nephropathies, neoplasms)
• significative coronary artery disease
• high-dose steroid therapy
• disease not enough evolved
• continuation of tobacco smoking and/or alcohol or drug addiction
• poor social environment
• total ventilator-dependance
Laboratory examinations : EKG, Holter, echocardiogram, right cardiac catheterism (+ coronarography if aged > 50 years), spirometry, ABG, 6-minute walking test, CO diffusion test, CXR, chest CT, perfusion and ventilation lung scintigraphy, bronchoscopy, psychiatric, ENT, infectivologic, nutritional and anesthesiologic visits.
Donor :
• main criteria : age < 55 years, AB0 compatibility, negative CXR, size compatibility, smoke < 20 packs/year, lack of significative trauma, lack of aspiration pneumonia and sepsis, negative PSH for chest surgery, PaO₂ >= 300 mmHg with FiO2 100% and PEEP 5 cmH₂O.
• final evaluation : not worsening of radiological picture, not worsening of oxygenation, lack of purulent secretions or neoformations at bronchoscopy, after direct lung visualization : lack of important adhesions, masses or contusions; size compatibility is evaluated with theoretical TLC estimated according to sex, age, and height.
Technique :
• explant : median sternolaparotomy => pleurotomy => lung inspection and palpation => isolation of inferior and superior venae cavae, aorta, pulmonary artery, and trachea => preparation and cannulation for explant of abdominal organs => cannulation of aorta and pulmonary artery => unfusion of heparin and PGE₁ => clamping of aorta and venae cavae => infusion of cold perfusion solutions (cardioplegic and pneumoplegic), drained through incision of inferior vena cava and left auricle. The heart is explanted by severing the aorta, venae cavae, pulmonary artery just upstream bifurcation, and left atrium leaving an atrial cuff containig the 4 pulmonary veins. En bloc pulmonary explant include the distal and proximal esophageal section, severing of trachea with mechanical stapler and mildly expanded lungs. All mediastinic tissue is pulled manually and severed at both sides of column and the ascending aorta is severed. Bench preparation involves separation of the 2 lungs, asportation of mediastinic tissue, and preparation of vascular and bronchial anastomoses. UW or Euro-Collins cold intracellular perfusion solutions (containing high potassium and causing vasoconstriction, which leads to dyshomogenous perfusion) are integrated with pulmonary vasodilators such as PGE₁ or PGI₂, or replaced by extracellular perfusion solutions (eg. low-potassium dextran (LPD) or Celsior)
• transplant : preparation of recipient with peridural catheter, cannulation of an artery, CVC and Swan-Ganz catheter, left double-lumen endotracheal intubation under bronchoscopic guidance. Single lung transplantation requires posterolateral thoracotomy at 5th intercostal space, while bilateral lung transplantation requires anterior bithoracotomy or anterior sternobithoracotomy. The lung with worst perfusion scintigraphy is replaced, also the first to be transplanted in bilateral transplantation. Hemostasis should be accurate as heparin used in extracorporeal circulation can cause pleural hemorrhages. The pulmonary artery is isolated at the hilus and severed with a vascular stapler after ligation of the first mediastinic branch. Veins are divided after ligation of peripheral branches. Finally the main bronchus is isolated and severed. After pneumonectomy a wide pericardiotomy is performed and the donor's lung surrounded by ice bands is placed into the recipient's pleural cavity : there is risk to cause a frigore phrenic nerve paralysis. Bronchial anastomosis is began with PDS 4-0 continuous suture of part membranacea, while pars cartilaginea is sutured end-to-end with separated stitches. If the 2 bronchi have very different diameters a telescopic anastomosis can be performed by inserting the smaller bronchus into the larger one and protected with recipient's mediastinic tissue or donor's pericardium avoiding excessive bronchial devascularization. End-to-end arterial anastomosis with Prolene 5-0 preventing excessively short or long (=> kinking) ends => venous anastomosis between atrial cuffs : in recipient it is achieved by placing an angiostat below the end of the 2 ligated veins, and, once removed the stitches of the mechanical stapler, by severing the atrial tissue between them to form a single orifice. This cuff is anastomised with the donor's lung one in continuous suture with Prolene 4-0. The suture is not knotted to allow deareation. For reperfusion the lung is moderately ventilated and the angiostat is enlarged over the artery assuring blood exits from atrial suture. Arterial clamp is then removed while the atrium is declamped and the atrial suture is completed. A similar procedure is performed for the contralateral lung in bilateral transplantation. At the end a control of hemostasis is performed preventing excessive lung manipulation; pleural drainages are positioned and chest is closed as usual. Hyposystolia or severe hypoxemia may require extracorporeal circulation from femoral level when right atrium and ascending aorta are not easily accessed (expecially during single lung transplantation) or centrally (ie a venous cannula in right atrium for blood deflow and a cannula in ascending aorta for reinfusion in bilateral lung transplantation). At the end of transplantation the double-lumen tube is replaced by a single-lumen tube under bronchoscopic guidance allowing also control of bronchial anastomosis and bronchial toilette
Complications :
• hemorrhage
• dehiscence of bronchial anastomosis
• stenosis of arterial anastomosis due to poor performance or kinking due to excessive length
• stenosis of venous anastomosis due to poor pericardial opening
• reperfusion edema
• mediastinic shift with hyperinflation of native lung in single lung transplantation for emphysema
• transplant rejection
• acute monitored via transbronchial biopsy :
• A0 : normal
• A1 (minimal) : poor perivascular infiltrates
• A2 (mild) : frequent infiltrates around venulae and arterioles
• A3 (moderate) : dense perivascular infiltrates extended to alveolar septa
• A4 (severe) : diffuse perivascular, interstitial, and intraalveolar infiltrates< damage of pneumocytes, possible parenchymal necrosis, infarction or necrotizing vasculitis
• chronic rejection due to HHV-5 / CMV = bronchiolitis obliterans syndrome, monitored by drop in FEV₁. Enhanced induction and maintenance immunosuppression along with aggressive treatment of acute rejections may delay the incidence of bronchiolitis obliterans syndrome and improve graft survival^{ref1, ref2, ref3, ref4}.
• bacterial infection
Prognosis :
• early mortality (first 3 months) is caused by infection (35%) or acute rejection (5%). The most significant factors responsible for immediate mortality are related to either the patient's medical condition (patient in intensive care unit prior to transplantation and/or requires mechanical ventilation) or the underlying diagnosis The factors responsible for late mortality continue to be infection and the presence of chronic rejection manifested pathologically as bronchiolitis obliterans syndrome, occurring in > 40% of patients by 2 years and cause of death in 50% of those affected
• late mortality (after the first 3 months) is caused by bronchiolitis obliterans (29%) => bronchiectasis, infections (30%), and cancer (6%)
1-year survival rates for lung and heart-lung transplantations worldwide remain lower (70% and 62%, respectively) compared with heart transplantations (83%). The 5-year survival rates are 70% for heart and 45-50% for lung transplantations. Long-term patient survival rates are dismal for all thoracic grafts: 22.3% at 18 years for heart, 20% at 9 years for lung, and 25% at 12 years for heart-lung recipients
Web resources : International Society for Heart and Lung Transplantation (ISHLT)
• tendon transplantation : surgical replacement of a damaged segment of tendon by a free tendon graft
• hand transplantation : long-term survival of animal limb allografts with new immunosuppressant combinations and encouraging results of autologous limb replantations led some teams to believe that clinical application of hand transplantation in human beings was viable. On Sept 23, 1998, the right distal forearm and hand of a brain-dead man aged 41 years was transplanted on to a man aged 48 years who had had traumatic amputation of the distal third of his right forearm by Prof Jean-Michel Dubernard at the Service de Chirugie de la Transplantation et d'Urologie, Hopital Edouard Herriot, in Lyon, France. The donor's arm was irrigated with UW organ preservation solution at 4°C, amputated 5 cm above the elbow, and transported in a cool container. We dissected the donor limb and the recipient's arm simultaneously to identify anatomical structures. Appropriate lengths of viable structures were matched. Transplantation involved bone fixation, arterial and venous anastomoses (ischaemic time 12.5 h), nerve sutures, joining of muscles and tendons, and skin closure. Immunosuppression included antithymocyte globulins, tacrolimus, mycophenolic acid, and prednisone. Maintenance therapy included tacrolimus, mycophenolic acid, and prednisone. Follow-up included routine post-transplant laboratory tests, skin biopsies, intensive physiotherapy, and psychological support. The initial postoperative course was uneventful. No surgical complications were seen. Immunosuppression was well tolerated. Mild clinical and histological signs of cutaneous rejection were seen at weeks 8-9 after surgery. These signs disappeared after prednisone dose was increased (from 20 mg/day to 40 mg/day) and topical application of immunosuppressive creams (tacrolimus, clobetasol). Intensive physiotherapy led to satisfactory progress of motor function. Sensory progress (Tinel's sign) was excellent and reached the wrist crease (20 cm) on day 100 for the median and ulnar nerves, and at least 24 cm to the palm by 6 months when deep pressure, but not light touch sensation, could be felt at the mid palm. Hand allotransplantation is technically feasible. Currently available immunosuppression seems to prevent acute rejection. If no further episode of rejection occurs, the functional prognosis of this graft should be similar to if not better than that reported in large series of autoreconstruction^ref.

In 1996, the Louisville Hand Transplant Team was formed to examine the possibility of performing a human hand transplantation. One of our first goals was to develop procedures for the transplantation of allografts of extremities in large animals^{ref1, ref2}. In contrast to prior studies of hand transplantation in primates, in which very high doses of cyclosporine and prednisone did not prevent rejection episodes and had many adverse effects^{ref1, ref2} (Skanes SE, Samulack DD, Daniel RK. Tissue transplantation for reconstructive surgery. Transplant Proc 1986;18:898-900), in pigs that received extremity transplants, rejection could be delayed with a regimen of cyclosporine, mycophenolate mofetil, and prednisone or a regimen of tacrolimus, mycophenolate mofetil, and prednisone^{ref1, ref2}. These results strengthened our belief that hand transplantation was feasible in humans. In November 1997, we organized an international symposium to discuss the scientific, clinical, and ethical barriers to performing hand transplantation in humans. Although some participants expressed reservations about the high level of immunosuppression that might be required to prevent rejection, the majority felt that, on the basis of the data presented (Barker JH, Jones J, Breidenbach WC, eds. Proceedings of the international symposium on composite tissue allotransplantation. Transplant Proc 1998;30:2687-2787), limb transplantation in humans should be attempted, provided an appropriate experimental protocol was strictly adhered to. They therefore decided to proceed with clinical hand transplantation, but only after they had obtained the approval of the Human Studies Committee at the University of Louisville Medical School in Louisville, Kentucky, and of an ethics committee composed of people not related in any way to the institutions involved in the Louisville Hand Transplant Team. They also made public and professional disclosure of our intention to proceed, invited local as well as national commentary from the lay and medical communities before the procedure, and assessed the risk–benefit ratio for the procedure^ref. Finally, on January 24, 1999, 4 months after the performance of the first human hand transplantation in France, a hand transplantation was performed at the Jewish Hospital of Louisville. After a comprehensive pretransplantation evaluation and informed-consent process, the left hand of a 58-year-old cadaveric donor, matched for size, sex, and skin tone, was transplanted to a 37-year-old man who had lost his dominant left hand 13 years earlier. Immunosuppression consisted of basiliximab for induction therapy and tacrolimus, mycophenolate mofetil, and prednisone for maintenance therapy. Results The cold-ischemia time of the donor hand was 310 minutes. There were no intraoperative or early postoperative complications. Moderate acute cellular rejection of the skin of the graft developed 6, 20, and 27 weeks after transplantation. All three episodes resolved completely after treatment with intravenous methylprednisolone and topical tacrolimus and clobetasol. Temperature, pain, and pressure sensation had developed in the hand and fingers by one year. At one year, the patient could perform many functional activities with his left hand that he had not been able to perform with his prosthesis, such as throwing a baseball, turning the pages of a newspaper, writing, and tying his shoelaces^ref.

Immunologically, transplanted skin triggers fiercer rejection than any other organ or tissue, so hand transplant recipients will have to take immunosuppressants for life and undergo frequent medical monitoring. The consequences of not doing so were grimly brought home by a presentation that Guoxian Pei, a professor of orthopedics at Southern Medical University in Guangzhou, China, made at the Sixth International Symposium on Composite Tissue Allotransplantation, held in Tucson, Arizona, on January 17 and 18: of about a dozen hands that have been transplanted (some single and some bilateral) in China, Pei said, most have undergone chronic rejection with progressive loss of function because the recipients could not afford to continue to take immunosuppressants or did not receive regular medical follow-up. At least 2 patients had their transplanted hand amputated. Psychologically, adjustment to a dramatically changed face will also be a gradual and potentially difficult process for recipients and their families
Rehabilitation program for a hand transplant recipient :
• week 1 : use of dynamic crane extension outrigger and brace; protected active range of motion
• week 2-3 : light electrical stimulation of wrist and finger flexor and extensor muscles; progressive tendon gliding and active-assisted exercise
• week 3-4 : anticlaw splint and spring-loaded metacarpophalangeal control glove
• week 5 : combination movement activities and exercise to increase strength and range of motion
• week 5-8 : light-resistance activities
• week 9 : muscle stretching and strenghtening with the use of dynamic splinting
• week 6-12 : exercise to improve forearm pronation, wrist and finger flexion, and pinch strength; increase in functional activities
• enteric flaps have demonstrated excellent reconstructive results for soft-tissue augmentation, defects of the oral cavity, oropharynx, hypopharynx, cervical esophagus, and contouring defects of the head and neck. Their main advantages include tissue pliability, tubed shape, ease of contouring, and the ability to secrete mucus. Recent studies report outcome measurements for flap loss, fistula rates, postoperative swallowing, speech, and cosmesis. Now that experience has been gained to the point of routine use of these flaps, randomized trials are needed to determine the functional advantages of the enteric flaps compared with other reconstructive options^ref. laparotomic => laparoscopic harvesting.
• gastro-omental flap
• free jejunal flap
• omental transplantation : modern surgical techniques of elongating of the omentum enable its use outside the abdominal cavity in management of complicated problems in thoracic cavity, upper and lower extremities and head and neck.
• intracranial omental transplantation is sometimes indicated for treatment of ischemia in the territory both of the anterior cerebral artery and of the posterior cerebral artery in certain cases with moyamoya disease. A gastroepiploic artery is anastomosed to a scalp artery in an end-to-side fashion, or in an end-to-end fashion. A gastroepiploic vein is anastomosed to a cortical vein in an end-to-side fashion^ref.
• overlay autogenous tissue (OAT) patch after iatrogenic surgical injury to large blood vessels in the abdomen or pelvis^ref.
• reconstructing defects of the lateral face after parotid tumor surgery and small defects after oropharyngeal tumor surgery^ref
• management of complex cardiothoracic surgical problems^ref
• liver transplantation (LT / LTX / LTx)
• orthotopic liver transplantation (OLT / OLTX)
History :
• in 1952 V. Staudacher performs the first orthotopic liver tranplants in 4 dogs at the Milan Polyclinic, with survival for only a few days
• in 1955 C. Stuart Welch in Albany, NY, described the experimental transplantation of an auxiliary liver to the right paravertebral gutter in mongrel dogs. Experiments at the University of Miami from 1956-1958 led the way to orthotopic liver transplantation. In 1958, orthotopic liver transplantations following hepatectomy were performed, although these attempts were marred by poor performance of the transplanted liver. The operative procedures were further refined by Jack Cannon at the University of California at Los Angeles in 1956 and by several investigators in Boston and Chicago from 1958-1960. These animals survived < 4 days due to a lack of effective immunosuppression; however, technical principles such as optimal portal revascularization, allograft preservation, and other techniques were perfected.
• Thomas E. Starzl attempted human liver transplantation on March 1 1963, at the University of Colorado in Denver on a 3-years boy affected by biliary atresia. Despite years of research into organ preservation, surgical technique, and understanding the physiological interrelationship of the liver with other intra-abdominal viscera, this did not prepare his team for the unexpected difficulties encountered in patients with end-stage liver disease and extensive portal hypertension. The first patient did not survive surgery, and 2 others died 7.5 and 22 days postoperatively. Subsequent similar failures in Boston and Paris led to a worldwide moratorium on liver transplantation. Initial attempts were unsuccessful because of a combination of technical difficulties and the unavailability of effective means to prevent rejection. As increased experience was achieved and with improvements in immunosuppression, prolonged liver recipient survivals were achieved. From 1963 to 1979, 170 patients underwent liver transplantation at the University of Colorado; 56 survived for 1 year, 25 for 13-22 years, and several remain alive with follow-ups of 17-31 years. In 1968, Roy Calne of Cambridge University founded the second liver transplantation program. As with renal grafts, the long-term survival rate after liver transplantation remained poor (18-30% 1-year patient survival) until the advent of cyclosporine^ref.
Epidemiology : 100,000 transplants performed up to 2001 (46,040 in 122 centers in USA since December 1988 to December 2000, ; 49,240 performed in 122 centers in Europe since May 1968 to June 2000; 2487 in South America at 1999; 1955 in Asia since 1995 to 1999); waiting list in USA at Sep 7 2001 = 18,367 (only 4954 performed in 2000); in Europe 40,000 transplants performed up to June 2000 (about 1,000 per year)
Donors :
• cadaver liver transplantation : ischemia time should be < 12 hrs, and donor body weight shouldn't exceed recipient's one by 10-20% (otherwise partial hepatectomy may reduce size); age should be < 60 years (22% are aged 50-60 years) due to higher prevalence of fatty liver disease after that age; exclude liver traumas, systemic infections or neoplasms, HBsAg, anti-HCV Ab, HIV; avoid : prolonged cardiac arrest or systemic arterial hypotension, dopamine infusion > 10 mg/kg/min, P_O2 < 60 mmHg, SGOT > 200 IU, SGPT > 100 IU, ICU staying > 6 days, edematous or steatotic macroscopic look. 1-yr OS = 70%, 5-yr OS = 61%, 10-yr OS = 54%
• partial bench hepatectomy of donor's liver may result in an organ including segments II-III with left suprahepatic vein for a pediatric patient or segments V-VI-VII-VIII with vena cava for an adult patient. It is no longer practiced.
• reduced-size liver transplants (RSLT / RLT) : the donor's vena cava is present
• partial liver transplant (Bismuth, 1981, on a 10-yo baby) : the donor's vena cava is not present
• split liver transplantation (SLT) : a single donor's liver is divided into 2 organs for 2 different recipients. According to the split plan (umbilical or main portal scissure) the hemilivers explanted usually consist on one side of
• the left lateral segment (segments II-III) and by the other side of the extended right graft (I, IV, VIII) (right trisegment)
• or of the left lobe (segments II-III-IV) and of the right lobe.
• ex situ (Pichlmayr, Hannover, 1988; Bismuth, Paris, 1989)
• in situ (Rogiers and Broelsch, 1994, Hamburg)
1-yr OS = 64%, 5-yr OS = 53%, 10-yr OS = 49%
• living related liver transplantations (LRLT) (Strong, 1987, Brisbane, Australia; Broelsch, Chicago, 1989); age should be 18-60 years. Donor mortality = 0.3-0.5%. The adequate ratio between the weight of the liver you need to donate and the recipient's weight is 1-2%. The recipients undegoes total hepatectomy with preservation of vena cava. For pediatric patients the left lateral segment (segments I and II) is used, while for adults the right lobe (segments V-VI-VII-VIII) is used. 2,500 LRLTs have been performed worldwide at half 2001, expecially in Kyoto, USA (992 at end 2000) and Europe (400). 1-yr OS = 79%, 5-yr OS = 73%, 8-yr OS = 72%
• domino (crossover) liver transplantation : a liver from a cadaver donor is transplanted into a recipient with a metabolic hepatopathy, whose liver is transplanted into a recipient with a more severe (neoplastic) hepatopathy
• auxiliary liver transplantation (Gubernatis, 1991, Hannover) : a partial liver implanted orthotopically near the native liver for a limited course of time. Once the patient has recovered, the auxiliary liver is removed and immunosuppressants discontinued.
Waiting lists are compiled according to Child-Turcotte-Pugh score or Malinchoc Model for End Stage Liver Disease (MELD) : for patients with primary biliary cirrhosis only the increase in bilirubinemia (> 10 mg/dl) is considered.
While awaiting for LTx, patients can be treated with bioartificial livers.
Preoperatory examinations on the recipient : PMH/PSH, CBC, electrolytes, BUN, creatininemia, glycemia, magnesemia, calcemia, phosphoremia, bilirubinemia, SGOT, SGPT, alkP, amylase, ammonium, PT, PTT, viral hepatitis and HIV markers, culture of urine, blood, sputum, pharynx and eventually ascitis fluid, dosage of ceruloplasmin and a₁-antitrypsin, AMA, ANA, anti-thyroid Ab, Ig, CXR, liver echography, abdomen CT, angiography of celiac trunk and superior mesenteric artery, ophthalmic, gastroenterological, pneumological, cardiologic, psychiatric, and social assistance examinations, abdomen MRI, brain CT an EEG
Indications :
• in babies :
• fulminant hepatitis
• viral (HBV and HCV)
• toxic (paracetamol, Amanita phalloides)
• drugs (valproate, disulfiram, halothane)
• other diseases (Wilson disease, type I tyrosinemia, Reye syndrome)
• chronic hepatopathies :
• hepatocellular : chronic active hepatitis B and C, cryptogenetic cirrhosis
• cholestatic : secondary biliary cirrhosis, sclerosing cholangitis, extrahepatic biliary atresia after Kasai operation (50%)
• intrahepatic familial cholestasis (Byler disease)
• Alagille syndrome
• Caroli disease
• inborn errors of metabolism : tyrosinemia, Wilson disease, erythropoietic protoporphyria, type III and IV GSD, enzyme deficiencies in urea cycle, primary hyperoxaluria, Crigler-Najjar syndrome, type II homozygous hyperlipidemia, lipid storage diseases (Gaucher disease, Niemann-Pick disease, Wolman disease, blue histiocytosis), a₁-antitrypsin deficiency, familial iron-storage diseases
• nonresectable malignant liver cancers : hepatoblastoma, hepatocellular carcinoma, cholangiocarcinoma
• others : Budd-Chiari syndrome, cystic fibrosis with liver failure, neonatal hepatitis
• in adults :
• fulminant hepatitis : viral, toxic, drugs, others (acute fatty liver of pregnancy, Wilson disease, Budd-Chiari syndrome),
• chronic hepatopathies : hepatocellular (posthepatitis B or C, cryptogenetic, alcoholic), primary cholestases (primary biliary cirrhosis or sclerosing cholangitis), inborn errors of metabolism (a₁-antitrypsin deficiency, Wilson disease, hemochromatosis, protoporphyria, familial amyloidotic neuropathy, familial hypercholesterolemia)
• malignant unresectable liver cancers (primary : stage I-II hepatocellular carcinoma, cholangiocarcinoma (accompanied by radio- and chemotherapy); secondary : neuroendocrine tumor)
• others : secondary biliary cirrhosis, secondary sclerosing cholangitis, polycystic liver, trauma, Caroli disease, echinococcosis, Budd-Chiari syndrome, benign tumors with severe symptoms (adenomas, mesenchymal hamartomas, lymphangiomatosis, fibrous hilar angiodysplasia, focal nodular hyperplasia, hemangioma)
Clinical and biochemical indications :
• for acute forms : bilirubin > 20 mg/dl, PT 30" higher than controls, coma grade >= 3
• for chronic forms :
• in cholestatic forms : untractable pruritus, untractable osteoporosis, relapsing cholangitis
• in hepatocellular forms : albumin < 2.5 mg/dl, PT 3" higher than in controls,
• in both : encephalopathy, hepatorenal syndrome, relapsing spontaneous bacterial peritonitis, untractable ascitis, relapsing cholangitis, hepatoma (hepatoblastoma without distant metastases, cholangiocarcinoma in association with radiotherapy and chemotherapy), portal hypertension with bleeding from esophageal varices, progressive nutritional deficiency
Contraindications :
• absolute : metastatic liver cancer, complex psychological and sociofamilial conditions (alcoholism, drug addiction), AIDS, uncontrolled systemic infections, diffuse spleno-mesentero-portal thrombosis, advanced cerebrovascular diseases (pulmonary hypertension), encephalopathy with irreversible damage
• relative : portal thrombosis (thrombendarterectomy or iliac/caval prostheses from the donor between mesenterosplenic confluence and portal vein), HBV DNA⁺ (lamivudine can prevent replication), HIV⁺ (HAART : 7 patients transplanted in Pittsburgh in 1998), nephropathy (cryoglobulinemia), cholangiocarcinoma, previous abdominal surgery, age > 65 years
Technique :
• explant : assess arterial anomalies, such as right hepatic artery from superior mesenteric artery or left hepatic artery arising from left gastric artery
• classic technique : isolation of elements of hepatic hilus => cold perfusion
• fast technique (Starzl, 1986) : proximal and subphrenic aortic clamping => retrograde perfusion => isolation of elements of hepatic hilus
• bench surgery to remove fragments of other tissues (diaphragm, right adrenal gland, lymph nodes) from liver and prepare vascular pedicles (portal, subhepatic and suprahepatic vena cava)
• removal of native liver in the recipient
• transplant : 4 end-to-end anastomoses (between suprahepatic cava veins, subhepatic cava veins, portal veins and hepatic arteries) under veno-venous extracorporeal circulation between left femural vein and vena porta, and left axillary vein. During this anhepatic phase the porta and inferior vena cava are clamped and the resulting venous hypertension might cause hemorrhage, systemic arterial hypotension and renal damage.


The 2 end-to-end caval anastomoses can be replaced by a single side-to-side anastomosis when the retrohepatic inferior vena cava has been preserved during hepatectomy : in this case the partial clamping of the recipient's inferior vena cava makes extracorporeal circulation not required. So extracorporeal circulation is limited to babies weighing > 15 kg and adults untolerant to the caval clampage test before undergoing the classic technique. The transplant is completed by a end-to-end choledo-choledochal biliary anastomosis over Kehr or hepatojejunal drainage, over excluded Roux loop => cholecystectomy

Complications :
• hepatobiliary complications :
• primary functional graft failure in the first 2-3 days after transplantation due to poor liver preservation, excessive ischemia time, hemodynamic instability of the donor before explantation, advanced age, fatty liver disease. Therapy : retransplantation
• hyperacute rejection is uncommon, although syndromes of fulminant graft failure due to immunological mechanisms have been described
• acute cellular rejection (70%) usually occurs at postoperatory day 8 and responds to high-dose steroids => OKT-3 => retransplantation. Laboratory examinations : liver biopsy, trans-Kehr cholangiography, ECD to exclude hepatic artery or portal vein thrombosis
• chronic rejection (5-17%), characterised by a progressive destruction of intrahepatic bile ducts which is irreversible, accomanied by obliterative arteriolopathy, foamy cells and vanishing bile duct syndrome. The principal targets of both acute and chronic liver allograft rejection are intrahepatic bile ducts and endothelium. The increased ability of these cell types to express MHC antigens and adhesion molecules may be responsible for their involvement and may be enhanced by the release of proinflammatory cytokines associated with viral infection, particularly HHV-5 / CMV and HHV-6. Although the importance of HLA matching remains unknown patients transplanted with ABO incompatible livers have a higher incidence of graft rejection. Lymphocytes probably instigate rejection but liver damage may result from the recruitment of several effector mechanisms involving the activation of neutrophils, macrophages and B cells as well as CTLs. Therapy : FK506 => retransplantation
• vascular thrombosis (2-7% in adults; 20% in children; higher with partial liver transplants) : hepatic artery (early, late or asymptomatic) > porta or cava veins
• hepatitis (CMV (50% without prophylaxis), EBV, VZV, HSV, adenovirus, HBV, HCV)
• dehiscence or stenosis of biliary anastomosis (10-50%)
• recurrence of original disease
• hepatitis B or C
• cancer : prognostic criteria include Marsh, Iwatsuki, Barcelona Clinic Liver Cancer Group, Mazzaferro, and Milan Criteria. Cancer diameter, number and vascular invasivity are the most important factors
• cholangiocarcinoma
• hepatocellular carcinoma (HCC) : HCC recurrence was associated with CsA exposure > 189.6 ng/mL (278.3 +/- 86.4 ng/mL in recurrent vs. 169.9 +/- 33.3 in tumor-free patients; P < 0.001). AFP (P = 0.032), microvascular tumor invasion (P = 0.044), and CsA exposure (P < 0.001) influenced recurrence-free survival at the univariate analysis; CsA exposure was the only independent prognostic determinant at multivariate analysis (P < 0.001). High CsA exposure favors tumor recurrence; CsA blood levels should be kept to the effective minimum in HCC patients. In the presence of pathologic and histologic risk factors, specific immunosuppressive protocols should be considered^ref
• extrahepatic complications
• infections (bacterial in 60-80%, viral in 20-40%, fungal in 5-15%, protozoal in 10%). 70% of severe infections and 93% of viral and fungal infections occur during the first 2 months
• PTLD (< 1.5% in adults; 5-4% with tacrolimus)
• various
• lung complications (78-86%; cause 5% of deaths) : pleural effusion, atelectasis, pneumonia
• renal complications (2% of deaths)
• neurological complications (23%), expecially grand mal (2% of deaths)
• postoperatory hemorrhagic complications, requiring surgery in 18%
• cardiocirculatory complications : systemic arterial hypertension => cerebral hemorrhages
• hemolytic complications due to AB0 mismatch
• gastrointestinal complications : hemorrhages, colic perforations, peptic ulcers, bleeding from anastomosis of Roux loop
Prognosis : 1-yr OS = 79% (82% in children aged 1-10 years; 80% in aged 15-45; 75% in aged > 60), 5-yr OS = 69% (76% in children aged 1-10 years; 70% in aged 15-45; 62% in aged > 60; 71% for cirrhosis, 58% for fulminant hepatopathies; 47% for cancers), 10-yr OS = 62% (73% in children aged 1-10 years; 64% in aged 15-45; 52% in those aged > 60 years)
Web resources :
• International Liver Transplantation Society (ILTS)
• European Liver Transplant Registry (ELTR)
• pancreas transplantation :
• Langerhans islets transplantation : only 14% of patients with IDDM can stop insulin replacement therapy after 1 year, as ASCs are often deficient.

Timeline^ref :
• 1893 : the first attempted islet xenograft using sheep pancreas fragments
• 1964-1965 : experiments in 1964 and 1965 proved that islet cells could be isolated by digestion of a whole pancreas and remain viable
• 1972 : Paule E.Lacy and E. Ballinger at Washington University successfully reverses chemically induced diabetes in rodents using  approximately 500 isolated pancreatic islets cells transplanted intraperitoneally. Following these findings, Kemp described a newer method of implantation, by intraportal injection and embolization of islet cells into the liver. This technique improved control of diabetes much more quickly than intraperitoneal transplantation. Islet cell transplantations in humans are usually allografts, which have higher rates of failure and require lifelong immunosuppression. C. Ricordi has performed much of the previous work on islet cell transplantation. The causes of islet cell graft failure include failure of the initial engraftment, insufficient islet cell mass, rejection, and islet injury caused by immunosuppressive agents. Islet cell autograft transplantation in patients with chronic painful pancreatitis does not require immunosuppression, and patients have better success rates. Because current immunosuppressive drugs affect islet function, the development of more effective and less toxic immunosuppressive drugs may improve the success rate of islet cell transplantation.
• 1986 : the development of the "automated method for islet isolation" enables sufficient numbers of human islets to be harvested for transplantation
• 1989 : diabetes temporarily reversed with short-lived insulin independence in a patient transplanted in St.Louis, USA
• 1990 : in Pittsburrgh, USA, prolonged insulin independence in islet-transplant recipients is achieved using the newly introduced immunosuppressive agent, FK506
• 1996 : in Giessen, Germany, improved peri-transplant management and immunosuppression results in 100% initial islet-graft function and 40% insulin independence after one year
• 1999 : James Shapiro and his team at the University of Alberta in Edmonton, Canada, began a series of islet transplantations in March, 1999, which has revolutionized the field and helped achieve remarkable success rates. The Edmonton protocol consists of percutaneous intraportal injection of blood type–matched islet cells under local anesthesia in the radiology department of a hospital. Once the islet cells embolize into the liver, they develop a blood supply and begin producing insulin. Most of the recipients of this therapy required 2 procedures performed over an average of 29 days in order to produce enough insulin to avoid exogenous insulin administration for maintenance of euglycemia. In the first published series of 7 consecutive patients with type 1 diabetes undergoing islet cell transplantation under this protocol, insulin independence was achieved in 80% of those monitored for 2 years. Much of the success of this protocol is attributed to the novel glucocorticoid- and cyclosporine-free (diabetogenic drugs !) sirolimus / rapamycin- and tacrolimus-based immunosuppression regimen (+ anti-IL-2 mAbs) used.
• 2001 : in Miami, USA, results similar to the Edmonton protocol were obtained using islets kept in culture before transplantation for up to 3 days, thereby eliminating the logistic impediments of immediate islet transplantation
• 2002 : in Houston, USA, the first successful series of transplants was carried out with islets prepared in Miami and shipped across state barriers, validating the islet-cell-resources (ICR) concept, recently introduced by the National Institutes of Health, National Center for Research Resources (NIH NCRR), with the establishment of regional islet-distribution centres.
• 2004 : > 100 successful islet transplants have been carried out in North America and Europe since the introduction of rapamycin-based immunosuppression by the Edmonton group, and the first multicentre trial of islet transplantation is completed by the NIH Immune Tolerance Network (ITN)
• 2005 : the first successful transplant of insulin-producing cells from a live donor — a mother to her daughter — is reported by Japanese scientists. Both the patient, a 27-year-old woman, and her mother, 56, are healthy and have normal blood sugar levels, and 22 days after the surgery, the young woman no longer needed insulin injections to regulate her blood sugar. The patient has more than double the blood insulin level compared with patients who received one cadaveric islet transplantation : people who receive cells from non-living donors tend to become insulin independent only after 2 or 3 such procedures. The patient is considered cured for now, but whether the disease will return is uncertain. The procedure was effective using less than half the mother's pancreas (about 10 mL of tissue) in a day-long operation. Transplantation of islet cells taken from cadavers may require up to 3 pancreases, though new techniques have been effective using just 1. The Japanese patient's diabetes was caused by chronic pancreatitis, so the risk of an autoimmune attack on the transplanted cells was reduced, and that might have improved her chances. The removal of half a pancreas could place the donor at risk of developing diabetes. Only those who have no evidence of prediabetes, obesity or other risk factors could be considered donors. Attempts in the late 1970s to transplant pancreatic cells from living donors failed, partly because the anti-rejection drugs available were primitive^{ref1, ref2}.
Epidemiology : 493 allotransplants performed since 1983 to December 2000 (insulin-dependance persisted in 66 patients after 1 month, 62 patients after 3 months, 54 patients after 6 months, 40 patients after 12 months, 22 patients after 36 months, 11 patients after 48 months, and 6 patients after 60 months)
Obstacles :
• isolation


(reproduced with permission from Nature Reviews Immunology (Vol 4, No. 4, pp 259-268 (2004)) copyright Macmillan Magazines Ltd)
The technologies currently used in human islet-cell processing are based on an automated method that was first introduced in 1986 and that rapidly replaced all previously tested procedures. The concept introduced by this method was to progressively disassemble the pancreas after injection of collagenase through the pancreatic duct. This process allowed gradual digestion of the organ into fragments of decreasing size, until cell clusters of the volume range of islets are released. A constant flow through the digestion chamber allows the released islets to pass through a screen and to be collected in separate compartments, in which further enzymatic action is blocked by cooling and dilution. A final purification step is carried out by density-gradient separation of the islets, now carried out using a COBE2991 cell processor, and usually 300,000-500,000 islets are isolated from each pancreas. Several qualitative and quantitative tests are used to verify the quality of the final human islet-cell product. Pre-transplant criteria that must be met include determination of the ..
• total islet-cell number (> 5,000 islet equivalents/kg recipient body weight)
• total pellet volume of the final solution (< 7 ml of tissue)
• islet-cell purity (> 30% of islets)
Product release criteria also include :
• negativity of a Gram stain (to detect the preence of contaminating bacteria)
• > 70% viability as assessed by fluorescent inclusion/exclusion yes.
However, the best predictive test of post-transplant functional competence is the reversal of diabetes after transplantationof an aliquot of islets into an immunodeficient (athymic) mouse. At present, research is underway to develop alternative technologies for the assessment of final islet-cell preparations, including assessment of ... :
• apoptosis
• ATP and oxygen consumption
• mitochondrial membrane potentials
..., towards definition of improved prospective product release test for the prediction of post-transplant islet-cell fuction
• availability of islets
• scarcity of organs
• infections from xenotransplantations
• reversal of diabetes for > 100 d in cynomolgus macaques after intraportal transplantation of cultured islets from genetically unmodified pigs without Gal-specific antibody manipulation. Immunotherapy with CD25-specific and CD154-specific monoclonal antibodies, FTY720 (or tacrolimus), everolimus and leflunomide suppressed indirect activation of T cells, elicitation of non-Gal pig-specific IgG antibody, intragraft expression of proinflammatory cytokines and invasion of infiltrating mononuclear cells into islets^ref.
• neonatal porcine islets to engraft and restore glucose control in pancreatectomized rhesus macaques. Although porcine islets transplanted into nonimmunosuppressed macaques were rapidly rejected by a process consistent with cellular rejection, recipients treated with a CD28-CD154 costimulation blockade regimen achieved sustained insulin independence (median survival, >140 days) without evidence of porcine endogenous retrovirus dissemination. Thus, neonatal porcine islets represent a promising solution to the crucial supply problem in clinical islet transplantation^ref.
• choice of heterotopic implantation site :
• liver : percutaneous intraportal infusion (commonly used Edmonton protocol)
• renal capsule : easily accessible during renal transplantation (rarely used)
• subcutaneous tissue : syngeneic islets transplanted into a SC, neovascularized device restored euglycemia and sustained function long-term. Removal of graft-bearing devices resulted in hyperglycemia. Explanted grafts showed preserved islets and intense vascular networks^ref.
• islet grafting : apoptosis is common, but the transplant can be repeated (usually 2 times)
• autoimmunity :
• isolated islets are more vulnerable than those located within exocrine pancreas
• autoantibodies
• rejection. Techniques : removal of passenger lymphocytes
• many immunosuppressive protocols have been  shown ineffective
• steroid-less protocols is associated with prolonged insulin-dependance, but not rapamycin-based Edmonton protocol
Early loss of transplanted islets : given the disparity between the availability of islets for transplantation and the number of potential recipients, it will be crucial maximize the number of healthy islets that can be engrafted from a single donor. Prevention of early islet loss, which is estimated to occur for up to 50% of the transplanted islet mass, would also contribute significantly towards the definition of tolerance protocols that can result in insulin dependence. Islets exposed to allogeneic blood are subject to an immediate blood-mediated inflammatory reaction that involves coagulation and complement activation^{ref1, ref2, ref3}. Interestingly, human islets express tissue factor, an integral component in the coagultion cascade; studies in an in vitro system have shown that heat-inactivated factor VIIa or antibody specific for tissue factor could inhibit this process^{ref1, ref2}. Moreover, increased levels of thrombin-thrombin-specific antibody complex are detected in islet-transplant recipients in the immediate post-transplant period^ref. In addition to complement activation and coagulation, a key role for macrophages and their pro-inflammatory products, such as IL-1 and TNF, in islet survival and function has been shown^{ref1, ref2, ref3, ref4, ref5}. Clearly, attempts to control intra-gradt inflammation, complement activation and coagulation in the early post-transplant period as a means to prevent unnecessary early graft loss will be important. Moreover, the link between intense inflammation and the stimulation of immune responses indicates that immunological, as well as non-immunological, graft loss might be reduced by these measures. The clinical application of islet transplantation is limited due to the limited source and the morbidity of systemic immunosuppression to prevent rejection. The 2 problems can be solved by using encapsulated islets : amniotic membranes are biocompatible natural immune barriers that allow moderate inflammation. Implanted amniotic sac capsules are vascularized with no thrombosis or rejection within the omental tissue from day 10 on with significant blood vessel formation starting on day 3 by IHC study^ref.
Web resources : International Islet Transplant Registry (ITR)
• whole pancreas transplantation

History : in 1891, pieces of dog pancreas autotransplanted beneath the skin by Hedon prevented diabetes after removal of the intra-abdominal pancreas. Subsequent experimentation with intrasplenic transplantation did not succeed because of graft necrosis. In 1894 the first subcutaneous xeno-transplantation of ovine pancreas was performed in a 15-year-old boy in London. In 1916, sliced human pancreas was transplanted into 2 patients, but the grafts were completely absorbed. In 1921 Banting and Best discovered insulin. Despite extensive animal experimentation, pancreatic transplantation did not become a reality until 1966 when W.D. Kelly performed the first human, whole-organ pancreatic transplantation for treatment of type 1 diabetes mellitus. Because of poor outcomes, few procedures were performed until 1978. Much of the early work was performed by Sutherland and colleagues at the University of Minnesota. With improved immunosuppressive regimens and newer surgical techniques, the 1980s ushered in a new era in pancreas transplantation. In 1973 the first ureteral diversion was performed, and in 1978 Dubernard at Lyon introduced the duct occlusion with synthetic polymers. In 1983 Corry and Sollinger proposed the vesical diversion. Enteric drainage was introduced by Groth in 1970 but was soon abandoned due to higher infection incidence
Epidemiology : nearly 14,000 pancreatic transplantations were recorded since December 1966 to 1998. Most of the pancreatic transplantations have been performed in patients with type 1 diabetes mellitus and a lack of insulin production. The most common indication is renal failure; therefore, pancreas transplantation is typically performed simultaneously with a kidney transplantation (95%; 1-yr OS > 90%). In some patients with hypoglycemic unawareness or other diabetic complications, isolated pancreas transplantation has been performed (5%; 1-yr OS = 70%). However, the results have been somewhat inferior to those of the combined procedure.
Indications :
• for isolated pancreas transplantation :
• preuremic nephropathy (proteinuria 0.15-3 g/day with creatinine clearance > 70 ml/min
• progressing retinopathy
• neuropathic pain or diabetic autonomic neuropathy
• severe difficulties in diabetes treatment (hyperlabile diabetes; resistance to subcutaneous insulin, loss of consciousness of hypoglycemic crises, staying at hospital > 90 days/year, >= 4 episodes of diabetic ketoacidosis in 1 year, >= 6 hypoglycemic crises a month)
• for combined pancreas-kidney transplantation : creatinine clearance < 45 ml/min
Contraindications for recipient : age > 55 years, severe cardiopathy or peripheral vasculopathy, cancer, psychiatric or infectious diseases
Donor : age < 40 years (while older donors are accepted for kidney transplantation). Contraindications : familiarity for diabetes mellitus, pancreas trauma, acute pancreatitis; hyperglycemia and hyperamylasemia are not contraindications
Technique :
• explant (2-3 hours) : Starzl procedure :
• segmental (corpocaudal) explant : left and right pancreasectomy
• whole pancreas and duodenal segment explant : accurate dissection of hepatic hilus extended to the celiac trunk and the origin of splenic artery => ligation and section of gastroduodenal artery => distal section of choledochus and wide mobilization of pancreatic head through Kocher maneuver => closure and section of duodenum just downstream the pylorus and at the level of Treitz ligament => transverse mesocolon is sectioned and mobilized at the base as the mesenter, ligating the superior mesenteric vessels at the level of the lower pancreatic border. Care is required to detect right hepatic artery arising from superior mesenteric artery (5-10%), essential for liver transplantation. In that case hepatic vascularization is adjusted at the bench on the celiac tripod or discarding the superior mesenteric artery which can be severed distally to the origin of the right hepatic artery maintaining anyway the origin of the inferior pancreatoduodenal artery, which guarantees vascularization of the head of the pancreas
Perfusion involves the infusion of 2 l of UW solution into aorta, which allows a cold ischemia time up to 15 hours : for a better pancreatic perfusion the porta vein can be sectioned 0.5-1 cm upstream the upper pancreatic border and insert a cannula for liver perfusion, while the proximal tract of the porta vein is left open. Alternatively the inferior mesenteric vein can be cannulated by clamping the cannula placed in the vena porta with a tourniquet at the level of hepatic hilus and sectioning the porta vein upstream to allow the venous discharge of the pancreas. Once perfusion is completed, organ preparation is performed by right-left pancreatectomy. Liver and pancreas can be explanted separately or en bloc together with a wide aortic patch including the origin of the celiac tripod and the superior mesenteric artery. Then the 2 vascular districts are separated at the bench by sectioning the splenic artery at the origin, leaving the celiac tripod for liver vascularization and the superior mesenteric artery for pancreas vascularization via the inferior pancreatoduodenal artery. The arterial pancreatic vascularization is then remade at the bench by performing an anastomosis between splenic and superior mesenteric artery or interponing an arterial prostheses from the iliac bifurcation of the donor.
• in segmental transplantation (30') : ligation and section of splenic artery and vein at splenic hilus => splenectomy => cannulation of Wirsung duct => injection of synthetic resin to block exocrine secretion => excannulation => accurate ligation of all small arterial and venous branches on the superior margin of the pancreatic capsule. Some centres use arterial prostheses (iliac arteries) to enlengthen the splenic artery when the celiac tripod is not available for anastomosis to iliac vessels of the recipient : the latter is difficult and risky if recipient's arteries are atherosclerotic or for organs with splenic artery < 3 mm in diameter.
• for whole pancreas and duodenal segment (3 hrs) : ligation with transfixed stitch and section of splenic artery and vein distally to splenic hilus => splenectomy => accurate ligation and section of all small arterial, venous and lymphatic vessels on the upper and lower borders of pancreatic capsule at the level of pancreas body. Preparation of duodenum at the upper and lower knees with ligation of duodenal arteries and section via GIA mechanical stapler to obtain a viscus 5-8 cm long => ligation of choledochus and superior pancreatoduodenal artery on the upper border of the head => preparation of mesenteric artery and vein from mesenteric adipose tissue with ligation and sectioning of vessels of accessory branches at 1-cm from the pancreatic surface on the lower border of the head => preparation of spenic and superior mesenteric arteries by performing end-to-end anastomoses using iliac bifurcation explanted from the donor. Particulary, anastomoses are performed between the splenic and hypogastric arteries of the innest and superior mesenteric artery and external iliac artery of the innest. The branch of the common iliac artery of the innest will be used for anastomosis in the recipient with a 6-0 polypropylene continuous suture after insertion of similar-diameter tutor. When the splenic artery is < 3 mm in diameter it is preferred to perform a separate stitch anastomosis. A more refined technical variant involves also conservation and restoration of gastroduodenal artery to reintegrate arterial vascularization of duodenum. In this case, still using the iliac vascular graft of the donor, the gastroduodenal and mesenteric arteries are implanted with 2 separate anastomoses (end-to-side anastomoses on the external iliac branch of the donor and end-to-end anastomosis between the splenic and internal iliac artery of the donor). Preparation of the porta vein (3-mm long after splenomesenteric confluence and end-to-end anastomosis with innest of donor's common iliac vein with 6-0 polypropylene double continuous suture after insertion of adequate tutor. In transplant with portal venous diversion, portal enlengthnment is contraindicated.
• transplant : wide laparotomy with xiphopubic incision (obliged in portal drainage) or alternatively bilateral J-shaped pararectal incision with extraperitoneal access for kidney transplant and intraperitoneal access for pancreas transplantation. Conventionally, the kidney is placed at left and the pancreas at right. Despite pancreas is more sensitive to ischemia than kidney, it is usually implanted after the kidney as 3 hours are required for bench preparation of the pancreas and the new kidney allows a better hemodynamic control. Preparation of common and internal iliac arteries choosing the one with less atherosclerosis and ligating periarterial structures to prevent postoperatory lymphorrhea => preparation of common iliac or superior mesenteric vein with sporadic ligations of collaterals to achieve a good mobilization => 2000 IU heparin in predialysis patients or s.c. LMWH in dialysis patients => common iliac vein (in systemic drainage) or superior mesenteric vein (in portal drainage) are clamped and venotomy is performed => first venous anastomoses with non-reabsorbed monofilament thread => arterial anastomosis (end-to-end if hypogastric artery is used or side-to-side if the external or common iliac artery is used), with pancreas still in hypothermia (warm ischemia time should be < 40') => simultaneous declamping => eventual hemorrhages due to poor bench preparation are treated with transfixed stitches as a new arterial clamping could cause thrombosis and graft loss. The pancreas is placed in iliac fossa, and, if possible, covered with omentum; an aspirating drainage is placed inferiorly at contact with the organ. See also kidney transplantation

Drainages :
• for exocrine secretions :
• segmental pancreatic transplantation with suppression of exocrine secretion by injecting synthetic resins (neoprene and prolamine flocculate at change in pH) in the ductal system. Side effect : atrophy and fibrosis of exocrine pancreas cause loss of endocrine function, too, and there is high incidence of graft loss due to early thrombosis.
• diversion of exocrine secretion in urinary apparatus. Advantages : inactivation of pancreatic enzymes, amylase monitoring in urine, conservative treatment of eventual dehiscence of duodenovesical anastomosis with Foley's catheter. Side effects : consistent loss of fluids and bicarbonates (=> dehydration and acidosis), peptic cystitis, urinary tract infections, hematuria, reflux pancreatitis, urethral rupture. Cystoenteric conversion (laparotomic demolition of duodenovesical anastomosis, vesicorrhaphy and cretion of side-to-side or Roux duodenoenteric anastomosis) is required in 10-20%


• diversion in digestive apparatus (first choice) obtained via pancreatojejunostomy in segmental transplantation or via end-to-side duodenojejunostomy or Y-exluded Roux loop in duodenal-pancreatic transplantation. OS is the same as for urinary diversion, but QOL is better.


• for endocrine incretions
• systemic diversion (80%) : anastomoses between donor porta vein (enlengthned with donor's iliac vein) and recipient's iliac vein => loss of hepatic first-pass effect => hyperinsulinemia => dyslipidemia and atherosclerosis
• portal diversion (20%) : Shokouh-Amiri end-to-side anastomosis between donor porta vein and a branch of superior mesenteric vein (when diameter is adequate to guarantee high flow). Flow of antigens to the liver seems to be beneficial and first pass effect on insulin is preserved. Arterial vascularization is guaranteed by an end-to-side anastomosis between the patch of common iliac artery passed through mesenteric operculum until it reaches the recipient's common iliac artery. The duodenum is anastomised to the ilium as for systemic drainage,
Metabolic control : normalization of FPG, delayed insulin incretion at OGTT (normalization of glycemia after 3 hrs => IGT) but normal at IGTT. Visual acuity improves in 56%, stable in 33%, and worsen in 11%. NCV improves in 75%.
Prognosis : 10% undergo transplant rejection (2% within 1 year). Survival rates : 95% after 1 year, 70-80% after 10 years (20% if patients undergoes hemodialysis), 50% after 36 years. In dyssynchronous transplantation 1-yr OS = 85% for 0-1 mismatches, 75% for 2-3 mismatches; in single transplantation 1-yr OS = 82% for 0-1 mismatches vs. 66% for 2-3 mismatches. 5-yr OS since beginning of hemodialysis = 94% in transplanted patients vs. 26% in untransplanted patients
Web resources : International Pancreas Transplant Registry (IPTR)
Web resources : International Pancreas and Islet Transplantation Association (IPITA)
• splenic autotransplantation after postinjury splenectomy is indicated in cases of injuries which result with conquassation or total devascularization of this organ. Splenic autotransplantation may have an effective role in management of thalassemia major in children^ref. This method is not recommended in the endangered patients, patients with previous disease of the spleen as well as in the patients with the perforation of the other abdominal organs at the same time. It has been advocated to augment the immune response to infection and prevent overwhelming postsplenectomy sepsis. The low quantity and poor quality of the regenerated splenic tissue contribute to the inferior immunoprotective ability of animals autotransplanted with one-third of the original spleen. This suggests that the regenerated spleen cannot compensate for the immunological function of the original one, especially host resistance to infection^ref. Immune responses such as production of antibody remain impaired in humans and animals even when such tissue is present, and clearance of particles from the blood is reported to be less efficient than by normal spleen tissue. Autotransplanted tissue contained fewer phagocytic cells than normal tissue, and these cells phagocytosed less per cell. Phagocytosis by spleen cells was dependent on heat-labile opsonic factors^ref.
• kidney transplantation (KT) : the native kidneys are removed only in patients with uncontrolled renal hypertension, relapsing renal infections, and bulky or symptomatic polycystic kidneys. The availability of EPO prevents renal anemia.
• renal xenotransplantation^ref
History : the first organ to be transplanted successfully
• 1906 : the first kidney transplantation in a human being was a pig xenotransplantation anastomised to brachial vessels by Jaboulay
• 1933-1939 : Voronay placed it over the thigh of a man poisoned by mercury bichlorhydrate which died after just 48 hours
• 1950 : Lawer places a kidney orthotopically in the retroperitoneum but fails due to technical problems
• 1951 : Kuss revisited the retroperitoneal technique
• December 25, 1952 : Hamburger performed the world's first renal transplantation from a living donor in a 15-year-old roofer who injured his solitary kidney. The donor of the graft was the patient's mother. The graft functioned immediately following surgery, but it unfortunately ceased to function on the 22nd postoperative day. The patient died 10 days later due to the unavailability of hemodialysis. However, this event had a considerable impact on the scientific community. Surgical inspection of the graft revealed that immunological rejection, rather than stenosis or thrombosis of the renal artery, led to graft failure.
• December 23, 1954 : Joseph Murray, winner of the Nobel prize in Medicine 1990, and Hartwell Harrison performed the first transplantation of a kidney graft between identical twins. This success was followed by subsequent attempts by Murray and Merrill that led to 7 successful transplantations between identical twins in Boston. Most of the recipients of identical twin kidney grafts performed by Joseph Murray did well; some still have functioning kidneys > 30 years after transplantation. However, the attempts at cadaveric renal transplantation universally resulted in graft failure due to rejection. The first attempts to control the immune system used total body irradiation. In 1958, a Boston-area woman who was accidentally irradiated with 6 Gy received a functional renal graft, although the patient died from bone marrow aplasia. In January and June 1959, first Joseph Murray and colleagues (Merrill) in Boston^{ref1, ref2} and then a Paris team led by Hamburger^ref irradiated 2 transplant recipients with a total dose of 4.5-4.8 Gy; the donors were nonidentical twins (haploidentical transplant). Both of these recipients had successful outcomes. The patients survived 20 and 26 years, respectively. The results were astonishing. Years of effort with animals had not yielded a single example of kidney recipient survival exceeding 73 days with any kind of treatment or >30 days with irradiation alone^{ref1, ref2, ref3}. In June 1960, Kuss and colleagues were faced with rejection in a kidney transplant recipient who received the graft from an unselected donor. The use of 6-mercaptopurine in this patient, an immunosuppressive agent previously studied in animals, reversed the rejection process and ushered in the era of medications for the prevention and treatment of rejection. In 1964, Crosnier performed another cadaveric transplantation with long-term successful function. In the early 1960s, the pioneering work of Thomas Starzl led to further advancements. His contributions were systematic studies using azathioprine and prednisone therapy to prolong graft survival. Following the demonstration of antilymphocyte serum efficacy by Waksman, Starzl conducted the first clinical trial of antilymphocyte globulin as an adjunct to azathioprine and prednisone in human kidney transplantation. At present, the 1-year patient survival rate for living donors is 98%, and the 1-year patient survival rate for cadaveric transplants is 95%. The graft half-life for living donors is approximately 20 years, and the graft half-life for cadaveric donors is 12 years. The outcome data from the UNOS annual report of 2002 shows that the 1-year survival rate for grafts from living donors ranges from 88.1-95% and the rate for cadaveric grafts increased from 79.7% to 87.1%. Furthermore, the half-life for grafts from living donors increased steadily from 12.7 to 21.6 years, and that for cadaveric grafts increased from 7.9 to 13.8 years. These short-term improvements are the possible result of cyclosporine; its effect on the long-term survival of kidney transplants is not known. Kidney graft failure occurs because of chronic rejection, graft dysfunction, and nephrotoxicity, causing the patient to need dialysis and often a new organ. The development of new therapeutic approaches to prevent chronic rejection is needed to prolong the long-term survival of kidney transplants^{ref1, ref2, ref3}.
• 2001 : in Italy > 1,400 KT have been performed (17.1 donors per million inhabitants (22.6 in the North, 16.3 in the Center, and 7.1 in the South); +12.3% respect to 2000)
Donors : cold ischemia time allowed up to 35 hours (usually 48 minutes)
• cadaver transplantation (warm ischemia = 0) : dialysis is required before undergoing cadaver transplantation
• living donor transplantation (usually aged < 65 years) (warm ischemia = 1-2 minutes)
• < 5' : normal
• 5-10' : borderline
• > 10' : ATN, postischemic polyuria
Preemptive KT is possible before the recipient undergoes dialysis.
Epidemiology : according to the Organ Procurement and Transplantation Network, 6647 people became living kidney donors in the United States in 2004^ref
Techniques :
• access :
• extraperitoneal lumbotomy from the side with eventual renal ptosis and normal vascular and/or ureteral anatomy. Common vascular variants include the early bifurcation of renal vein, the double arterial district (10%), and the retroaortic vena cava. If anatomy is normal, consider that the left renal vein is longer, but left renal artery is shorter, and the opposite happens on the right side. Anyway in patients with double arterial district the right kidney is preferred because often ptotic, easier accessible and at higher risk of complications in pregnant females. The patient is placed laterally to maximize the space between the last rib and the iliac crest. The incision starts from the lower border of the 12th rib and ends at the lateral border of the ipsilateral rectus abdominis muscle. The subperiosteal resection of the 12th and 11th rib may be required. The external oblique, internal oblique and transverse muscles, fascia trasversalis and Gerota's capsule are incised sparing peritoneum and pleura.
• median transperitoneal xiphoumbilical access if the donor has cholelithiasis or appendicitis (treated immediately after explantation and synthesis of paracolic pouch)
• subcostal transperitoneal access allows treatment of abdominal diseases eventually preexisting in the donor and causes less postoperatory pain
• thoracoabdominal incision is no longer used due to postoperatory pain
• videolaparoscopy : living kidney donation skyrocketed after the introduction of laparoscopic living-donor nephrectomy for left kidney, but when circumstances require removing the right kidney (which has a more complicated anatomy), the surgery often involves more conventional techniques, with longer recoveries and longer scars. A new surgical clamp allows hand-assisted laparoscopic surgery (HALS) for either operation. Few patients would not donate if told laparoscopy wasn't available, but all would prefer less-invasive surgery.
• isolation of ureter sparing the periureteral adipose tissue containg the vessels. The kidney is mobilized together with its adrenal gland. If the left kidney is explanted, the section is performed between the adrenal and gonadal veins : the second lumbar vein or azygo-lumbar arch (occurring in 30%) should be resected on both sides before explantation to prevent renal vein laceration. Renal vessels are isolated starting from cava and aorta towards renal hilus. If the 2 right veins are near they can be explanted together with a small cava vein patch. Medial kidney rotation is useful to isolate renal artery from the surrounding nerve and lymph vessels. 5 mg of i.v. furosemide are administered => renal clamping is performed when ureteral urine flow is good (usually after 10 minutes). The right renal vein is clamped with Satinski angiostat with partial inferior vena cava clamping. The renal artery is ligated with 3/0 polypropylene thread and a second transfixed stitch is applied : this is because metal clips could interfere with the mechanical stapler. The endovascular stapler creates 5% extra arteries for implantation when cannot pinch proximally to aorta : nonreabsorbable plastic Weck's closure system ("hem-o-lock"). The left renal vein is resected as for the left renal artery, while at right after heparin lavage a double suture over the inferior vena cava is clamped with Satinsky, with 2 double-needle polypropylene 6/0 to prevent caval stenosis.  The kidney is explanted and immersed in a cold perfusion solution. Careful rehydration of donor. In lumbotomic access, intercostal nerves should be blocked with long-acting anesthetic : fibrinolytic prophylaxis in elderly or obese donors. A soft Jackson-Pratt drainage is left and removed after 24-48 hours (as the urinary catheter). Mobilization within 24 hours is expecially recommended in elderly and obese donors to allow better intestinal canalization and respiratory function. A CXR is practiced to exclude PNX due to the lumbotomic access. In the first 24 hours, ABP, hematocrit and plasma electrolytes are monitored every 4 hrs : the elastic lower limb bandage is removed when deambulation restarts after 2 days. A low-salt, low-protein diet is recommended for the first 6 months in the donor. Biannual check-ups in the donor.
Complications : early major complications (pneumothorax, hemorrhages, pulmonary, urinary tract and wound infections, DVT and adrenal gland injuries) occur in 0.23-2.5%; risk of  mortality for the donor (due to pulmonary embolism and general anesthesia) = 0.03%. No late complications other than mild proteinuria and systemic arterial hypertension
Laboratory examinations :
• pathological anatomy investigations (ischemia time = 4 hrs) :
• PAS + Masson trichromic method
Morphological score :
• glomerular sclerosis
• tubular atrophy
• interstitial fibrosis
• arteries and arterioles
• 0 : normal
• 1 : wall thickness < lumen diameter
• 2 : wall thickness = lumen diameter
• 3 : wall thickness > lumen diameter
Global score :
• 0-3 => donor idoneous for single transplant
• 4-6 => donor idoneous for double transplant
• 7-12 => nonidoneous donor
Indications : end-stage renal disease (ESRD)
Contraindications : metastatic cancers, infectious diseases (TB, AIDS, active hepatitis B, chronic infections), evolutive cardiopathy, chronic respiratory failure, diffuse atherosclerosis, active peptic ulcers, untreatable coagulopathies, focal glomerulosclerosis on native kidney, lupus nephritis, HUS, oxalosis, and, in undeveloped countries, lack of economic resources to follow the immunosuppressive treatment, psychic lability
Transplant : heterotopic extraperitoneal transplantation in right or left iliac fossa (the left kidney goes in the right fossa and viceversa because the iliac vessels are reversed !) because of simpler and faster preparation; easily isolated and high-flow vessels; low-infection location; shorter distance to urinary bladder => only the proximal 2/3 of the ureter, vascularized by branches of renal artery, are used; easy location for palpation, biopsy, echography, and pyelostomy; wider space for polycystic kidneys); iliac incision => pararectal transit through muscular plans => detachment of parietal peritoneum => skeletization of iliac vessels and ligation of lymph collectors (eventually cranial widening of incision and homolateral nephrectomy) : the renal vein is anastomised end-to-side to the external iliac veins (rarely the common iliac vein or the vena cava), while the renal artery is anastomised end-to-end to the external iliac artery (rarely the common iliac artery). The ureter is anastomised to the urinary bladder with Grégoir-Lich technique

Kidneys with multiple vessels (occurring in 25-30% of cases) can be implanted with conventional revascularization or after bench reconstruction to reduce second warm ischemic time. Sometimes 2 kidneys are implanted when the donor is an elderly.
Prognosis : in syngrafts organ and patient survival are 100%; cadaver transplant has 1-yr OS = 94% (88% of organ survival) and 5-yr OS = 81%; in the short-term, cadaver transplants has a 28% higher failure rate than child-to-parent transplants. In the long-term, the risk of failure is 18% higher for cadaver transplant recipients and the death rate 12% higher than in child-to-parent transplant recipients. The average gain in kidney transplant survival is about 3.5 years for a child-to-parent compared with a cadaveric kidney transplant : this gain for the recipient far outweighs the 0.03% risk of death to the donor associated with donating a kidney. The average age of a child to parent donor is 30 years. 10% of recipients transplanted at age 20 can reach age 80 with a functioning kidney
Complications :
• acute rejection :
• acute cellular rejection (ACR) : Feucht et al.^{ref1, ref2} first proposed the use of C4d staining of peritubular capillaries (PTC) in the renal allograft biopsies to identify patients with severe cellular rejection and associated C4d with pretransplant panel reactive alloantibodies. C4d negative in peritubular capillaries (PTC) :
• type 1 (tubulointerstitial)
• type 2 (endarteritis)
• acute humoral rejection (AHR) : nearly 20 yr after the observation by Jeannet et al.^ref that posttransplant, de novo, donor-specific antibodies are associated with a poor outcome, this area is attracting renewed attention. Circulating cytotoxic antidonor HLA class I antibodies can be detected in about 23 to 38% of patients with ACR^{ref1, ref2}. These rejection episodes typically have an aggressive clinical course. A series of patients selected for circulating de novo donor-specific antibodies and biopsy features regarded as typical of AHR was reported, including peritubular capillary/glomerular neutrophils with or without fibrinoid necrosis^ref. Although morphologic features^{ref1, ref2, ref3, ref4} may sometimes distinguish AHR from ACR, the diagnosis might be missed if the typical features of AHR are focal or if cellular rejection is also present
• type 1 (capillary)
• type 2 (arterial fibrinoid  necrosis)
Measurement of higher mRNA for FOXP3 (a specification and functional factor for regulatory T lymphocytes; 90% sensitivity and 73% specificity with use of cutoff 3.46 log-transformed mean (+/- SE) ratio of FOXP3 mRNA copies to 18S ribosomal RNA copies) or lower mRNA for CTL proteins granzyme B and perforin^ref in urine may offer a noninvasive means of improving the prediction of negative outcome of acute rejection of renal transplants, which is difficult to predict even with an allograft biopsy^ref
• acute tubulointerstitial rejection (AIR)
• HHV-5 / CMV
• acute vascular rejection (AVR)
• anti-HLA antibodies
• IgG₁ and IgG₃ antibodies that bind to 2 different epitopes on the second extracellular loop of the AT₁ receptor : affected patients might benefit from removal of AT₁-receptor antibodies or from pharmacologic blockade of AT₁ receptors^ref
Grading : Cooperative Clinical Trials in Transplantation (CCTT) classification system and incorporated into the revised Banff criteria^{ref1, ref2}
• AIR is defined by lymphocytic infiltration in the interstitium (i score) with a lymphocytic tubulitis (t score)
• AVR is defined by intimal or transmural arteritis (v score)
Each of these criteria is graded variously 0-3 and in the original Banff schema (1993) acute rejection is then graded according to severity of both tubulitis and arteritis. Grade II acute rejection encompasses severe tubulitis without arteritis and mild/moderate arteritis. Glomerulitis (g score) and and the presence of other inflammatory cells, such as neutrophils and eosinophils, are also noted but their presence is of uncertain significance and is not used in the grading of rejection. While several studies have provided evidence that the presence of acute vascular rejection is an adverse prognostic factor, both in the short- and long-term, the importance of severity of tubulitis is less certain. In recognition of this uncertainty it was proposed to replace grades with types of rejection at the 1977 Banff conference or renal allograft pathology.
Therapy : 500 mg/day methylprednisolone for 3-5 boluses reverse 75% of first rejections => if resistant, OKT-3 reverses 94% of first rejections

	rejection rate
induction : RATG 2 mg/kg/day  for 7 days + basiliximab 20 mg 4 days apart (begin after first dialysis);  maintenance = CsA (C0 = 15-250 mg/ml), steroid, MFF (750 mg twice daily); daclizumab alone without CsA allows reduction but not delay in using CsAref; steroid and CsA increase CAN and other side effectsref	6%
induction : alemtuzumab 20 mg day 1, 0 maintenance : CsA (C0 = 75-125 mg/ml)ref	16%
alemtuzumabref	100% (monocyte rejection in absence of T lymphocytes)
alemtuzumab + low sirolimusref	30%
alemtuzumab + TAC + MFFref	9%
alemtuzumab 80 mg i.v. + sirolimus + MFF (Remuzzi, 2004)
alemtuzumab 80 mg i.v. + sirolimus + CsA

Alemtuzumab induces a relative and absolute increase in peripheral blood T_Reg concentrations (on renal histology ?), inducing specific tolerance, but it is not possible to suspend it.
Rituximab for AB0 incompatible renal transplantation^{ref1, ref2}
• chronic allograft nephropathy (CAN) is influenced by :
• alloantigen-dependent factors
• non-immunological determinants
• donor factors :
• age
• cause of death (atherosclerosis)
• recipient factors
• cardiovascular complications, as hypertension and hyperlipidemia
• infection
• HHV-5 / CMV
• HHV-6
• HHV-7
• BKV
• drug nephrotoxicity
• procurement factors : warm ischemia
• acute tubular necrosis (ATN)
• vascular complications
• hemorrhage
• hypocoagulability
• septic arteritis
• spontaneous renal rupture (3-6%) due to rejection, tubular necrosis and previous biopsies. Explant is indicated only for deep fractures or hematuria, and surgical repair can save kidneys
• stenosis of vascular anastomosis
• renal artery thrombosis
• pelvic lymphocele
• ureteral stenosis and fistulas
• infection
• cyclosporine toxicity :
• rapamycin inhibits the progression of dermal Kaposi's sarcoma in kidney-transplant recipients while providing effective immunosuppression^ref
• a study of > 700 renal-transplant recipients in the Netherlands disclosed that the overall incidence of squamous-cell carcinoma was 250 times that of untransplanted controls^ref
• neurological complications are frequent in renal transplant recipients and may largely contribute to morbidity and mortality. The postransplant neurological complications may be categorized into five areas: 1) Immunosuppressive medications, 2) stroke, 3) peripheral neuropathies, 4) infection, and 5) malignancies. A number of complications are directly caused by the neurotoxicity of immunosuppressive agents. Calcineurin-inhibitors may cause mild symptoms, such as tremors and paresthesia, or severe symptoms, such as disabling pain syndrome and leukoencephalopathy. Severe neurological syndromes may also be caused by the monoclonal antibody OKT3. Stroke may occur in about 8% of renal transplant patients. It may be favored by systemic arterial hypertension, diabetes mellitus, and accelerated atherosclerosis which may be acquired during dialysis or after transplantation. Peripheral mononeuritis and polyneuritis may also occur. An acute femoral neuropathy may occur in about 2% of patients as a result of nerve compression after operation. Guillain-Barre syndrome may also develop, triggered in some cases by HHV-5 / CMV or Campylobacter jejuniinfection. Lymphomas are the most frequent brain tumors. They are usually associated to a HHV-4 / EBV infection and are more frequent in patients who received an aggressive immunosuppressive therapy. Infection represents the most frequent neurological complication. Acute meningitis usually caused by Listeria monocytogenes, subacute and chronic meningitis caused by Cryptococcus neoformans, focal brain infection caused by Aspergillus fumigatus, Toxoplasma gondii or Nocardia asteroides, and progressive dementia caused by JC virus or other viruses are the most frequent types of neurological infection^ref
Expression of C3 alleles (F (fast) and S (slow)) by donor renal cells appears to have a differential effect on late graft outcome (loss and function). Among white C3S/S recipients, receipt of a C3F/F or C3F/S donor kidney, rather than a C3S/S donor kidney, is associated with a significantly better long-term outcome. These findings suggest that the two alleles have functional differences^ref.
• intestinal transplantation (IT) : an arterial anastomosis between superior mesenteric artery of the donor organ and the aorta of the recipient, and a venous anastomosis between the superior mesenteric vein of the graft and the porta vein (or the superior mesenteric vein, or, rarely, the cava vein) of the recipient. 200 transplants performed worldwide (3-yr OS = 70%)
• isolated small bowel transplantation (SbTx) : jejunum + ilium
• small bowel + large bowel transplantation

Indications :
• congenital or acquired intestinal agenesis
• isolated intestinal dysfunction
• short-bowel syndrome not treatable by home parenteral nutrition
Web resources : Intestinal Transplant Registry
• parathyroid autograft : usually implanted in forearm muscles after total or subtotal parathyroidectomy due to primary or secondary hyperparathyroidism
• fatty tissue autograft
• combined transplantation
• multivisceral transplantation
• simultaneous pancreas-kidney (SPK) transplantation

Indications :
• hepatorenal syndrome
• renal failure in patients with diabetes mellitus
The waiting time is obviously shorter when the cadaver pancreas transplantation is combined to a living-donor kidney transplantation.
• combined liver-intestine transplantation was first developed in the 1950s. The arterial anastomis is performed between the aortic wall of the donor (including the celiac trunk and the superior mesenteric artery) and the aorta of the recipient : an arterial prosthesis is often required between them. The cava vein anastomosis is as in liver transplantation. Finally an anastomosis between the porta vein of the recipient and that in the multivisceral block is required to ensure the portal venous flow to native organs (stomach, duodenum, pancreas, spleen)

Indications : liver failure due to prolonged TPN, secondary to short-bowel syndrome
• combined kidney-pancreatic islets transplantation
• total multivisceral transplantation = liver-pancreas-stomach-small bowel-large bowel (the whole gastroenteric apparatus from cardias to rectosigmoid junction) +/- kidney; first attempted by Starzl et al in 1962 on canine models of liver transplant rejection; first made by Starzl himself on a human being in 1983. The intrahepatic portion of inferior vena cava, the whole abdominal aorta and part of the thoracic aorta are transplanted, too, while the spleen is resected. Experienced only by 7 patients during the cyclosporine age, all died shortly (the best result achieved  a 320-days survival). From 1985 to 2001 : 656 patients (42% isolated bowel transplantation; combined liver-intestine transplantation in 35%; multivisceral transplantation in 23) transplanted, 317 still alive : in last years, around 100 patients per year are operated, with 1-yr OS = 65-80%. Just before clamping the arteries in the donor, a lavage with cold organ perfusion solution is practiced to improve organ preservation (up to 24 hours for liver, up to 36 hours for kidneys). Cathartics and antibacterials (amphotericin B, gentamycin and polymixin E) are administered to the donor via the NGT to sterilize the lumen. Apart from gastrointestinal and vascular anastomoses, a pyloroplasty is performed to allows better gastric emptying and a temporary ileo- or colostomy is left to monitor stool transit and make biopsies to assess transplant rejection and GvHD (no markers of rejection exist for intestine).

Indications :
• diffuse arterial and/or venous splanchnic thrombosis associated to liver failure
• pseudo-obstruction syndrome with liver failure
• aganglia with liver failure
Complications : infections and hemorrhages facilitated by liver failure
• partial multivisceral transplantation :
• small bowel +/- large bowel
• liver-intestine +/- large bowel
• combined heart-liver transplantation
• combined heart-liver-kidney transplantation
• combined heart-lung transplantation
• combined heart-lung-kidney transplantation
If the viscera can be conceptualized as a cluster of grapes hanging from its arterial stems, the procedures are characterized by virtually identical vascular anastomoses, with exclusion or inclusion of as many viscera (grapes) as necessary; however, these procedures languished for nearly four decades because of the imperfect immunosuppressive regimens of the 1960s, 1970s, and 1980s. Finally, after the development of FK506, pediatric patients may undergo intestinal transplantation with the hope for long-term survival. These procedures are reserved for TPN-dependent children with permanent intestinal insufficiency. Candidacy for transplantation is also predicated on development of potentially fatal TPN complications such as cholestasis, recurrent sepsis, or thrombosis of access sites. Overall survival of 65%
• skin transplantation : rapid and effective coverage of burn wounds is an important determinant of survival after major thermal injury.
• autologous skin transplantation / dermatoautoplasty :
• many patients lack enough donor sites to completely cover the burn wound with autologous split-thickness skin grafts.
• tissue-engineered skin generated from single cell suspensions : this readily allows therapeutic of pharmacologic ex vivo manipulations for decreasing immunogenicity ad resistance to inflammatory attacks by the immune system. Furthermore they do not contain professional APCs that are the main stimulators of alloreactivity in the host. Unfortunately for emergency cases, autografts cannot be used because of the lengthy delay entailed in culturing autografts, generally a minimum of 10 days to generate confluent sheets and 3 to 4 weeks if large areas requiring secondary cultures are needed.
• allogeneic keratinocyte grafts (Apligraf^®, Appligraft^®, Dermograft^®) from unrelated donors have been used as a readily available alternative for immediate cover of severely burned patients. Keratinocyte allografts are devoid of passenger leukocytes and could potentially provide immediate, unlimited amounts of material for permanent wound coverage, if they were not susceptible to rejection (see gene therapy). However, although early reports of successful keratinocyte allograft transplantation were supported by the finding that recipient blood group antigen expression was absent on epidermal cells at the allografted site and by the lack of stimulation of the mixed epidermal cell lymphocyte reaction between donor keratinocytes and recipient lymphocytes, more recent investigations have failed to provide convincing evidence that the survived grafted keratinocytes are of donor origin even though frank allograft rejection is not observed. It is now well established that allografts may be rejected in the absence of direct allopresentation (lack of professional donor APCs) via the indirect allopresentation pathway mediated by host APCs that infiltrate the graft within 2 weeks following transplantation and pick up donor alloantigens (expecially MHC class I molecules) and present them to host T cells in the draining lymph nodes. These controversial results have highlighted the difficulties in establishing whether keratinocyte allografts can be used for more than a temporary skin covering.
• dermatoheteroplasty / heterodermic graft : the grafting of skin derived from a member of another species
• delayed graft : a skin graft which is sutured back into its bed and subsequently shifted to a new recipient bed
• Reverdin epidermic graft : a piece of epidermis implanted upon a raw surface
• dermal, dermic or cutis graft : skin from which epidermis and subcutaneous fat have been removed; used instead of fascia in various plastic procedures
• full-thickness graft : a skin graft consisting of the epidermis and the full depth of the dermis
• Krause-Wolfe graft : a graft of full thickness of the skin
• split-thickness graft : a skin graft consisting of the epidermis and a portion of dermis.
• split-skin graft : a skin graft consisting of the epidermis and about 1/3 of the dermis.
• thick-split graft : a skin graft consisting of the epidermis and about 2/3 of the dermis.
• pinch graft : a small split-thickness skin graft
• mesh graft : a thin split-thickness skin graft in which many tiny splits have been made to allow the graft to expand and be stretched to cover a large area.
• Blair-Brown graft : a split-thickness skin graft of intermediate depth
• Ollier-Thiersch thin-split graft : a very thin skin graft consisting of epidermis and a thin layer of dermis, often cut in long, broad strips
• Thiersch's operation : removal of thin split-thickness skin grafts by means of a razor, skin-graft cutting knife, or a dermatome.
• hyperplastic graft : a skin graft that is in a state of active repair
• Esser-Stent inlay graft : a skin or mucosal graft applied by spreading the graft over a stent and suturing the graft and mold into a prepared pocket
• outlay graft : a modification of an inlay graft, used in ectropion of the eyelid
• sieve graft : a skin graft from which very small circular islands of skin are removed so that a larger denuded area can be covered, the sievelike portion being placed over one area, and the individual islands over surrounding or other denuded areas.
• epidermatoplasty : skin grafting done by transplanting pieces of epidermis to denuded areas.
• ovarytransplantation
• autologous ovary transplantation : ovaries are very sensitive to cytotoxic treatment, especially to alkylating agents and ionising radiation, generally resulting in loss of both endocrine and reproductive function^ref. Moreover, uterine irradiation at a young age reduces adult uterine volume^ref. By 2010, about one in 250 people in the adult population will be childhood cancer survivors^ref. Several potential options are available to preserve fertility in patients facing premature ovarian failure, including immature and mature oocyte cryopreservation, and embryo cryopreservation^{ref1, ref2}. For patients who need immediate chemotherapy cryopreservation of ovarian tissue is a possible alternative^{ref1, ref2, ref3}. Currently, only a limited number of clinics will freeze eggs or ovarian tissue for cancer patients about to undergo chemotherapy : this is an important deficit of cancer care^ref. Some are concerned that the technique could be used by healthy menopausal women who choose to delay motherhood for reasons of convenience. If the success rate is > 30%, similar to that of in vitro fertilization, then it is a possibility. Fertility and ovarian endocrine function can be preserved in women by long-term ovarian tissue banking^ref. The aim of the strategy is to reimplant ovarian tissue into the pelvic cavity (orthotopic site) or a heterotopic site like the forearm once treatment is completed and the patient is disease-free^{ref1, ref2, ref3, ref4, ref5, ref6}. However, one major concern surrounding use of ovarian cortical strips for orthotopic autotransplantation is the potential risk that the frozen-thawed ovarian cortex might harbour malignant cells, which could induce a recurrence of disease after reimplantation. Shaw and colleagues^ref reported that ovarian grafts from AKR mice could transfer lymphoma to recipient animals. Nevertheless, findings of other studies have suggested that ovarian tissue transplantation in Hodgkin's disease is safe^{ref1, ref2, ref3}. Confirmation of the absence of malignant cells by light microscopy might not be sufficient, especially in some types of cancer (eg, haematogenous or systemic neoplasms)^ref. Screening methods to detect minimal residual disease must be developed to eliminate risk of cancer cell transmission with reimplantation^ref. To date, ovarian tissue has been successfully cryopreserved and transplanted in rodents, sheep, and marmoset monkeys^{ref1, ref2, ref3}. Experimental studies have indicated that the fall in number of primordial follicles in grafted tissue is due to hypoxia and the delay before reimplanted cortical tissue becomes revascularised. The loss of primordial follicles in cryopreserved ovarian tissue after transplantation is estimated to be 50–65% in some studies^{ref1, ref2, ref3}. In one trial, in which ovarian cortex was grafted onto the uterine horn and under the skin, the loss was > 90%^ref. Oktay and colleagues^ref suggested that oocyte quality might be compromised by transplantation to a heterotopic site. Indeed, they only obtained a 4-cell embryo from 20 oocytes retrieved from tissue transplanted under the skin of the abdomen. Temperature and pressure changes in the subcutaneous space could damage the oocytes. Peritoneal tissue is superior to subcutaneous tissue as a site of transplantation, with loss of fewer follicles in peritoneal tissue^ref. Follicles at an early growth stage need > 85 days to reach the antral stage^ref. Primordial follicles obviously need even more.
• cryopreservation of ovarian tissue in liquid nitrogen and DMSO at -196°C with subsequent autotransplantation has effectively preserved fertility in a sheep model^ref,
• Oktay and colleagues have reported laparoscopic transplantation of frozen-thawed ovarian tissue to the pelvic side wall^ref, forearm^ref, and beneath the skin of the abdomen. Eggs that were aspirated from cryopreserved ovarian tissue transplanted in heterotopic sites did not result in a pregnancy : a 30-year-old woman with breast cancer before chemotherapy-induced menopause, and this tissue was transplanted beneath the skin of her abdomen 6 years later. Ovarian function returned in the patient 3 months after transplantation, as shown by follicle development and oestrogen production. The patient underwent 8 oocyte retrievals percutaneously and 20 oocytes were retrieved. Of the 8 oocytes suitable for in-vitro fertilisation, 1 fertilised normally and developed into a 4-cell embryo, but no pregnancy happened after transfer^ref.
• Radford and colleagues^ref reported a patient with a history of Hodgkin's disease treated by chemotherapy, in whom ovarian tissue had been biopsied and cryopreserved 4 years after chemotherapy and later reimplanted. In this case, histological section of ovarian cortical tissue revealed only a few primordial follicles because of the previous chemotherapy. After reimplantation, the patient had only one menstrual period
• in 2004, a successful fertilisation and pregnancy after egg collection from fresh transplanted ovarian tissue in a primate has been described^ref: the grafted tissue functioned without any surgical connection to major blood vessels.
• a 32-year-old woman was diagnosed with stage IV Hodgkin's disease in 1997 and had 5 biopsy samples—about 12–15 mm long and 5 mm wide—from the left ovary : removal of the whole ovary was not an option because one can never completely exclude recovery of ovarian function after chemotherapy. Indeed, premature ovarian failure after chemotherapy is dependent on age, drug used, and dose given, and does not happen in all cases. Freezing of ovarian tissue was undertaken according to the protocol described by Gosden and colleagues^ref. After laparoscopy, the patient received MOPP/ABV hybrid chemotherapy from August, 1997, to February, 1998, followed by radiotherapy (38 Gy). The patient became amenorrhoeic shortly after initiation of chemotherapy. After chemotherapy and radiotherapy, concentrations of follicle-stimulating hormone (FSH) were 91.1 mIU/mL, luteinising hormone (LH) 85 mIU/mL, and oestradiol 17 pg/mL, confirming castration. This ovarian failure profile was confirmed 3 months later. Hormone replacement therapy (HRT) was started in June, 1998, and then stopped in January, 2001, because the patient wanted to become pregnant. A thorough evaluation by oncologists showed that she was disease-free. After cessation of HRT, concentrations of FSH, LH, and 17b-oestradiol returned to levels consistent with ovarian failure. From January, 2001, to December, 2002, the patient had only one ovulatory cycle shown by a progesterone concentration of 10 ng/mL, and presence of a corpus luteum on the left ovary, diagnosed by vaginal echography. The decision to reimplant the cryopreserved tissue was therefore taken. In 2003, after the disease had been treated to remission, after freeze-thawing, orthotopic autotransplantation of ovarian cortical tissue was done by laparoscopy. 5 months after reimplantation, basal body temperature, menstrual cycles, vaginal ultrasonography, and hormone concentrations indicated recovery of regular ovulatory cycles. Laparoscopy at 5 months confirmed the ultrasonographic data and showed the presence of a follicle at the site of reimplantation, clearly situated outside the ovaries, both of which appeared atrophic. From 5 to 9 months, the patient had menstrual bleeding and development of a follicle or corpus luteum with every cycle. The appearance of the first follicle in the grafted tissue 5 months after reimplantation is totally consistent with the expected time course. This time interval seen in our study between implantation of cortical tissue and the first oestradiol peak (5 months) is also consistent with data obtained from sheep and human beings^{ref1, ref2}. From 5 to 9 months after reimplantation, concentrations of FSH, 17b-oestradiol, and progesterone showed the occurrence of ovulatory cycles. At 9.5 months, the patient had a sudden and temporary surge in FSH (79 mIU/mL). 3 weeks later, the patient ovulated and, from this ovulation, became pregnant. We cannot explain this sudden and temporary surge in FSH. Possibly, it was associated with a decline in inhibin secretion, as suggested in the sheep model^{ref1, ref2}, or with slower follicular growth from a poor follicular reserve in the graft. Indeed, because of the loss of primordial follicles in the transplant, the follicular density was low but, in any case, the total amount of cortical tissue transplanted is fairly unimportant. After transplantation, the patient would have been regarded as a poor responder because, of the 500–1000 primordial follicles that would have been transplanted, > 50% would have been lost owing to hypoxia^ref. The FSH surge seen here probably served to favour follicle recruitment. In October 2003, 11 months after reimplantation, hCG concentrations and vaginal echography confirmed a viable intrauterine pregnancy, which resulted in the livebirth of a healthy girl, weighing 3.72 kg, with an Apgar score of 9 at 1 min, 9 at 5 min, and 9 at 10 min. She is the first to fall pregnant after such a procedure. However, since the woman had ovulated before transplantation, it is uncertain whether the egg came from the native ovary or the transplanted ovary. Several lines of evidence lend support to our assertion that the origin of the pregnancy was the autotransplanted cryopreserved tissue. First, the patient had, in total, 3 ovulatory cycles over a period of > 2 years. All originated from the left native ovary, which was proved by laparoscopy, echography, or both. Second, the native right ovary never showed any ovarian activity at all (no follicles, no corpus luteum). Third, even if we cannot absolutely exclude the presence of isolated follicles in the atrophic ovary, their density must be very low, since serial sections of four large biopsy samples of atrophic ovaries failed to detect any follicles. Fourth, laparoscopy showed, by direct visualisation, the development of a follicle from the grafted tissue 5 months after reimplantation. Fifth, on histological examination, the biopsy samples indicated not only survival of primordial follicles in the grafted tissue but also maturation of a follicle (granulosa cells marked by inhibin A). Sixth, after follicular development was shown by laparoscopy and histology, the patient had regular menstrual bleeding. The concentration of progesterone was systematically > 10 ng/mL in the mid-luteal phase, calculated on the basis of basal body temperature. During every ovulatory cycle (from 5 to 9 months), vaginal echography showed a corpus luteum on the grafted tissue outside the right atrophic ovary, which had shown no ovarian activity for almost 3 years. Finally, vaginal echography revealed the presence of a preovulatory follicle at the reimplantation site during the cycle leading to the pregnancy, but no follicles were seen on either of the native ovaries^ref.
• a 28-year-old woman after non-Hodgkin’s lymphoma was diagnosed, a firstline chemotherapy regimen (VACOP-B) was administered, but a relapse occurred 6 months later; during that period the patient had monthly menstrual cycles. A second-line regimen (MINE–ESHAP) was administered, followed by high-dose chemotherapy (BEAM) with autologous stem-cell support, a much more intensive form of chemotherapy than the 2004 patient. Ovarian tissue was harvested for cryopreservation before high-dose chemotherapy. She had definitely experienced complete ovarian failure following her cancer therapy, and had entered early menopause. During the ensuing 24 months, the amenorrhea persisted, and laboratory testing consistently revealed high levels of FSH and LH (40-104 IU/l) and undetectable levels of AMH and inhibin B — findings consistent with ovarian failure. At 24 months, the patient remained free of disease and requested autotransplantation of the ovarian tissue in an attempt to restore fertility. After approval from the institutional review board and the patient’s written informed consent had been obtained, a laparotomy was performed. 3 pairs of 5-mm transverse incisions were made in the left ovary through the tunica albuginea. With blunt dissection, cavities were formed beneath the cortex for each of the 3 strips. Each piece of thawed ovarian tissue (1.5 by 0.5 cm in area and 0.1 to 0.2 cm in thickness) was gently placed in a cavity, and the incisions were closed with 4/0 Vicryl sutures. Small ovarian fragments immersed in oocyte wash buffer were injected beneth the cortex of the smaller right ovary. Only the ovarian strips placed in the left ovary resumed function. 8 months after transplantation, the patient spontaneously menstruated. Basal levels of antimüllerian hormone (which previously was undetectable) were found to be high, a finding consistent with the presence of active, early-stage, growing follicles^ref. This change was followed by a rise in inhibin B levels to the levels reported in ovulatory women. Ultrasonography revealed a preovulatory follicle in the left ovary. The time from transplantation to recovery was compatible with the time needed for the growth and maturation of primordial follicles^ref. 9 months after transplantation, the patient had a second spontaneous menstrual period. The level of FSH was 7.9 IU/l, the level of LH 6.8 IU/l, the level of estradiol 118 pg/ml, and the level of progesterone 0.5 ng/ml. A decision was made to perform in vitro fertilization. After a modified natural cycle using GnRH antagonist^ref, a single mature egg with a large cumulus was retrieved. The egg was fertilized in vitro with sperm from the patient’s husband, and 2 days later, a 4-cell embryo was transferred to the uterus. Serum testing for hCG was positive 12 days after the embryo transfer. Repeated ultrasonography during the pregnancy showed normal fetal growth and development. At 38 weeks 5 days of gestation, a healthy-appearing female infant weighing 3000 g was delivered by cesarean section. The Apgar cores were 9 at 1 minute and 10 at 5 minutes. Tissue was harvested in this patient after therapy, with no evidence of disease, and conventional histologic analyses showed no cancer cells. Although the possibility that the egg was derived from the native ovary cannot be ruled out, this possibility is very unlikely, given the consistent evidence of ovarian failure after high-dose chemotherapy and the timing of restoration of ovarian function after transplantation. The hormone levels provided strong evidence of the success of transplantation, despite its being performed after initial chemotherapy, rather than of the activity of a few residual follicles. These results indicate that fertility preservation with cryopreservation and orthotopic transplantation of ovarian tissue can be successfully performed in humans^ref.
• heterologous ovary transplantation : this approach does not involve preservation of fertility and hence is not applicable to women facing sterilizing chemotherapy. After receiving an ovarian transplant from her monozygotic twin sister April 2004, Stephanie Yarber of Muscle Shoals, Alabama gave birth to a healthy baby girl on June 2005. The success story follows a number of recent achievements in the field. A whole-ovary transplant between sisters was reportedly performed in China in April 2002. The procedure is likely to work only with genetically identical twins for the moment, but the procedure will become viable for others when more easily tolerated immunosuppressant drugs are created, as these stop the body rejecting implants. In the meantime, in vitro fertilization remains the only option for most women. For people without identical twins, egg donation is the way to go. For unknown reasons, Yarber became prematurely menopausal at the age of 14. After 2 unsuccessful attempts at in vitro fertilization, Yarber's sister, who has had 3 children, agreed to donate an ovary to her identical twin. An ovary was removed from Yarber's twin and the 'skin' of the organ collected. A third of this tissue was frozen and the rest was grafted on to Yarber's ovaries. Nearly 3 months later, Yarber got the first period she'd had in 10 years and about 3 months after that she found she was pregnant. Conception was natural and pregnancy and delivery were completely normal^ref. It is sensible for some women concerned about their future fertility to have their ovaries preserved : this study is a proof of principle for work with cryopreservation of ovarian tissue. Frozen ovaries could be used to recover fertility in cancer patients, for example, whose chemotherapy may kill their eggs. The successful transplant of previously frozen ovaries into goats which then produced embryos, could revolutionise the cryopreservation of human organs. Scientists from the Centre of Agricultural Research in Bet Dagan removed and then froze the ovaries of 8 goats before successfully transplanting them back into 5 goats with 2 of these animals producing 6 embryos. This approach could revolutionise the field of cryopreservation for diverse human applications, such as organ transplants, as well as helping women who face the loss of their fertility (Amir Arav in the journal of human reproduction)
• uterus transplantation : transplantation of the uterus would relieve the anguish of women who greatly desire to conceive a child. Some women do not have a uterus. In some cases this is due to a congenital absence (Rokitansky's syndrome). In other cases, surgical removal of the uterus was required to repair an obstetrical rupture. Mice with transplanted wombs from genetically identical animals have given birth to healthy pups (75% of implanted embryos) but wombs grafted into mice of different strains failed after just a week. The donor source for a uterus may be an otherwise healthy living patient who requires uterus removal as a standard care procedure : a woman could receive a donor uterus from a relative (a mother or sister who has finished having children) to minimize the risk of rejection, but women would still need to take immunosuppressants. However long-term use of anti-rejection medication can make patients prone to viral infections, and raise the risk of blood cancer. Once a woman has finished having her family, she could stop immunosuppressive therapy and have the uterus removed. Womb transplants could help up to 4% of infertile women, including people who have had their uterus removed after an infection, cancer or during emergency operations. The technique could also provide an alternative to surrogacy.
• bone chips : small pieces of bone, usually cancellous, generally used to fill in bony defects to facilitate recalcification^ref
• brain transplantation^ref
Viral pathogens have emerged as the most important microbial agents having deleterious effects on SOT recipients. Antiviral chemoprophylaxis involves the administration of medications to abort transmission of, avoid reactivation of, or prevent progression to disease from, active viral infection.
• HHV-5 / CMV is the major microbial pathogen having a negative effect on SOT recipients. CMV causes infectious disease syndromes, augments iatrogenic immunosuppression and is commonly associated with opportunistic superinfection. CMV has also been implicated in the pathogenesis of rejection. Chemoprophylactic regimens for CMV have included oral aciclovir (acyclovir) at medium and high doses, intravenous and oral ganciclovir, and the prodrugs valaciclovir (valacyclovir) and valganciclovir. CMV prophylactic strategies should be stratified, with the highest-risk patients receiving the most 'potent' prophylactic regimens.
• HHV-1 / HSV-1 reactivation in SOT recipients is more frequent, may become more invasive, takes longer to heal, and has greater potential for dissemination to visceral organs than it does in the immunocompetent host. Prophylactic regimens for CMV are also effective chemoprophylaxis against HSV; in the absence of CMV prophylaxis, aciclovir, valaciclovir or famciclovir should be used as HSV prophylaxis in seropositive recipients.
• HHV-3 / VZV
• primary VZV after SOT is rare and most commonly seen in the paediatric transplant population because of VZV epidemiology
• zoster occurs in 5-15% of patients, usually after the sixth post-transplant month. Prophylactic regimens for zoster are neither practical nor cost effective after SOT because of the late onset of disease and low proportion of affected individuals. All SOT recipients should receive VZV immune globulin after contact with either varicella or zoster.
• HHV-4 / EBV has its most significant effect in SOT as the precipitating factor in the development of post-transplant lymphoproliferative disorders. Antiviral agents that could be effective are the same as those used for CMV, but indications for and effectiveness of prophylaxis are poorly established.
• HHV-8-associated lesions seem to be extremely rare in the Central European transplant population^ref
• HBV and HCVare important pathogens in the SOT population as indications for transplantation. So-called 'prophylaxis' for recurrent HBV and HCV after liver transplantation is controversial, suppressive rather than preventive, and potentially lifelong.
• HIV-1
• influenzavirus infection after SOT is acquired by person-to-person contact. During epidemic periods of influenza, transplant populations experience a relatively high frequency of infection, and influenza may affect immunosuppressed SOT recipients more adversely than immunocompetent individuals. Antiviral medications for prevention of influenza are administered as post-exposure prophylaxis to SOT recipients, in addition to yearly vaccine, in circumstances such as influenza epidemics and nosocomial outbreaks, and after exposure to a symptomatic individual during 'flu season'.^ref
Invasive fungal infections (IFI) in SOT recipients : expecially Candida albicans
• overall : 2.5%
• kidney transplant : 1.1%
• pancreas transplant : 3.4%
• liver transplant : 4%
• 3-mo OS after IFI : 72%
See also vaccinations for SOT recipients
Web resources :
• American Share Foundation
• American Society of Transplantation (AST)
• Australasian and South East Asian, Tissue Typing Association (ASEATTA), Inc.
• European Society for Organ Transplantation (ESOT)
• European Transplant Network (ETN)
• European Organ Exchange Organisation (EOEO)
• EUROpean DONor and Organ Registry (Eurodonor)
• Laboratory of Transplantation Immunology at the University of Nebraska Medical Center, Omaha, NE.
• NIAID Plan for Research on Immune Tolerance : Clinical Trials of Transplant Tolerance
• Organización Catalana de Trasplantes (OCATT)
• Organ Procurement and Transplantation Network (OPTN)
• Scandiatransplant is a Nordic organ exchange organisation and it covers a population of 24 million inhabitants in five countries, Denmark (5.3 million), Finland (5.2 million), Iceland (280,000), Norway (4.4 million), and Sweden (8.9 million)
• South-Eastern Organ Procurement Foundation (SEOPF)
• Transplant Center at University of Michigan
• TransplantHealth
• Transplant Pathology Internet Services (TPIS) at the University of Pittsburgh
• TransWeb
• United Network for Organ Sharing (UNOS)
• Journals
• Transplant Immunology

• 1597 : reconstruction of thenose by tissue grafting
• 1628 : early theory on the circulatory system developed
• 1666 : blood transfusion between 2 dogs
• 1667 : blood transfusion between sheep and human
• 1682 : repair of human skull with dog skull bone
• 1822 : first successful fresh skin autograft
• 1881 : first temporary skin graft
• 1883 : development of Ringer's solution for keeping tissues alive outside the body
• 1901 : identification of different blood groups
• 1905 & 1906 : first reports of corneal transplants
• 1905 : discovery of technique for growing tissue cells in vitro
• 1905 : successful direct blood transfusion between humans
• 1908 : early attempt at knee replacement surgery (using a cadaver for the replacement part)
• 1949 : role of immune system in tissue rejection identified
• 1953 : demonstration of acquired immune tolerance to foreign grafts
• 1954 : kidney transplant between identical twins
• 1956 : first successful bone marrow transplant
• 1958 : identification of the importance of the histocompatibility system for tissue matching
• early 1960s : Keith Reemtsma, a surgeon at Tulane University in New Orleans, transplantede chimpanzee kidneys into 6 patients and launched the modern era of xenotransplantation. One person survived for a startling 9 months.
• 1963 : first liver transplant
• 1966 : first successful pancreas transplant
• 1967 : first successful heart transplant by Christian Neethling Barnard, South Africa. Patient survived 18 days
• 1969 : first biocompatible ceramic that could bond to collagen and bone developed
• 1973 : successful unrelated bone marrow transplant
• 1978 : the immunosuppressant cyclosporine is introduced
• 1981 : a peripheral nerve bridge is implanted into the injured spinal cord of an adult rat
• 1983 : first successful single lung transplant
• 1984 : 12-day old Baby Fae receives heart from baboon and survives 20 days
• 1986 : first successful double lung transplant
• 1990 : FK506 immunosuppressant becomes available
• 1990 : first living donor lung transplant
• 1995 : Jeff Getty receives a baboon bone marrow transplant
• 1997 : transplant of pig neurons in patients with Parkinson's disease
• 1998 : human hand transplant
• 1998 : total larynx transplant

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