Liver Transplantation

Liver transplants are the second most common solid organ transplants.

(See also Overview transplant.) Liver transplants are the second most common transplants of solid organs are. The indications for liver transplantation include cirrhosis (70% of the transplants in the United States, 60 to 70% of these cases are attributed to hepatitis C) Fulminant hepatic necrosis (about 8 %) hepatocellular carcinoma (about 7%) Biliary atresia and metabolic disorders (primarily in children is approximately 3%) Other cholestatic (eg., primary sclerosing cholangitis) and non-cholestatic (e.g., autoimmune hepatitis) disorders (about 8%) A transplantation indication exists in patients with hepatocellular carcinoma and a tumor size of <5 cm or up to 3 tumors of <3 cm (Milan criterion), and in some fibrolamellar types. In patients with liver metastases transplantation is indicated only if there is a neuroendocrine tumor that develops no extrahepatic growth after removal of the primary tumor. To severe contraindications to liver biopsy Increased intracranial pressure (> 40 mm Hg) or lower cerebral perfusion pressure (<60 mm Hg) in patients with fulminant hepatic necrosis Severe pulmonary hypertension include (mean pulmonary arterial pressure> 50 mm Hg) sepsis Advanced or metastatic hepatocellular carcinoma All these conditions lead to poor results during or after transplantation. Liver donor Nearly all donated organs come from AB0 compatible brain dead (deceased) donor with a compatible size, still working heart. Prospective typing and HLA matching is not always necessary. AB0-incompatible liver transplants have been successfully transplanted in children <2 years; in older children and adults, these transplants are not made, because they carry a high risk of rejection and of bile duct damage (Ductopenia) with cholestasis, which would require a re-transplantation. Every year about 250 transplants from living donors are provided that can live without her right lobe of the liver (transplantation between adults) or the lateral segment of the left lobe. The advantages of such a donation for the receiver are in shorter waiting times, shorter retention periods of explanted organs in cold solutions, resulting in fewer cold-related Leberischämien, but especially in the better planning of transplantation and in the optimization of patient condition. The disadvantages for the donor is a mortality risk of 1/600 to 1/700 (by comparison, is the risk of mortality in renal transplantation from living donors at 1/3300) and complications (esp. Bile loss) for up to a quarter. Doctors must make every effort to make a psychological coercion of donors is prevented. Few livers from deceased heart-dead donors (called donation-after-cardiac-death [DCD]) removed. In such cases, however, develop in up to one third of recipients biliary complications, because the liver had been damaged by the ischemia prior to donation. To the donor (dead or alive) - Risk factors for graft failure in recipients include age> 50 steatosis increased liver enzymes, bilirubin, or both prolonged stay in the ICU hypotension makes vasopressors required hypernatremia may transplants from female donors to male recipients But since the imbalance between supply and greatest need for liver transplants (and growing because the prevalence hepatitis-induced cirrhosis increases) are increasingly accepted organs from donors who are> 50 years old on the one hand and on the other those with cold-related Leberischämien resulting from shorter retention periods. Furthermore, organs from donors with and fatty infiltration with viral hepatitis may be used (for transplantation in recipient with an induced by viral hepatitis cirrhosis). Other techniques for increasing the provision of care split liver transplantation: livers from deceased donors are divided into right and left lobe or in the right lobe and left lateral segments (in or ex situ) and divided into 2 recipients. Domino Transplantation: (. E.g., amyloidosis) Occasionally a donor liver of a deceased to a recipient with an infiltrative disease is added and the explanted diseased liver is implanted an older receiver which can benefit from the diseased liver, but the effects of the dysfunction of the graft will probably not live to see. Despite these new techniques, many patients die while waiting for a transplant. In some clinics liver supportive measures (extracorporeal perfusion with suspensions of cultured hepatocytes or potentially immortalized hepatoma) are used to obtain patient alive until a liver is available or subsides acute malfunction. Organ Distribution Before allocation available to such organs are patients on the national waiting list, evaluated according to a prognostic scoring system in adults is creatinine, bilirubin and INR values ??(after the Model for End-Stage Liver Disease [MELD ] based in adults), and (according to the model for Pediatric End-Stage Liver Disease [PELD] in children age, serum albumin and bilirubin and INR and measurements of growth impairment oriented for children). MELD and PELD formulas are used to calculate the probability that a patient will die from liver disease while waiting for a liver transplant. Patients to die more likely to receive a higher priority in the selection of a suitable donor. the mortality risk is assigned a score for patients with hepatocellular carcinoma, based on tumor size and wait time. Clinical Calculator: MELD score for end stage liver disease (NOT appropriate for patients aged under 12 years) Clinical Calculator: MELDNa score for end stage liver disease (not suitable for patients under 12 years) Clinical Calculator: PELD score for end stage liver disease (for patients under 12 years) procedure organs from deceased donors are removed after an exploratory laparotomy confirmed that no intra-abdominal diseases exist that speak against a transplant. Living organ donors undergo lobar or segmental resection. The organs are perfused after explantation and before transplantation up to 18 h in a cold solution stored; with extended storage time, however, the incidence of graft failure and ischemia-like biliary damage increases. The hepatectomy the recipient is the biggest challenge, as there are in the patients frequently portal hypertension and Koagulationsdefekte. Intraoperative blood loss can be> 100 units in rare cases, but can be collected through the use of cell saver devices, the intraoperatively obtained blood processed and thus reduces the required transfusion of foreign blood red blood cell concentrates to an average of 5-10 units. After hepatectomy anastomoses between the suprahepatic V. be prepared cava of the donor with the vena cava of the recipient in an end-to-side procedures (piggyback technique). The portal vein of the donor and recipient, the hepatic artery and bile ducts are then anastomosed. Thus, a bypass pump is not necessary to transport the portal vein into the general venous circulation. The heterotopic (not in its normal position) liver Implantationn that provides the patient with a liver auxiliaries, bypassing several technical difficulties. Because of the disappointing results, however, this technique is limited to the experimental setting. The immunosuppressive regimens vary (see table: immunosuppressants for the treatment of transplant rejection). In general, the transplantation monoclonal anti-IL-receptor antibodies are administered with a calcineurin inhibitor (cyclosporine or tacrolimus), mycophenolate mofetil and corticosteroids in the day. treatment with corticosteroids may be tapered over a few weeks and often discontinued after 3-4 months except in patients with chronic active hepatitis. Compared to other transplants of solid organs, the lowest doses of immunosuppressive agents are required in liver transplantation. Complications rejection from still unknown reasons Leberallotransplantate be less aggressive than others repelled Organallotransplantate. Contrary to expectations come hyperacute rejection in patients who are already sensitized to HLA and AB0 antigens, not so often, so immunosuppressants can be in this patient group often reduced relatively quickly and eventually discontinued. Most acute rejection crises are mild and self-limiting, occur during the first 3-6 months and do not affect the survival of the graft. Risk factors for the rejection Junior receiver age higher donor age include Larger HLA mismatch Longer periods of cold ischemia autoimmune diseases worse nutritional status (eg. As in alcoholism) appears protective. The symptoms of acute rejection depend on the type of rejection (see Table: manifestations of liver transplant rejection by category). They occur in about 50% of patients, while symptoms of chronic rejection in <2% occur. Manifestations of liver transplant rejection by category Ablehnunskategorie manifestations hyper acute fever, highly elevated liver enzymes (AST, bilirubin), coagulopathy Speeds fever, coagulopathy, highly elevated liver enzymes (AST, bilirubin), ascites acute therapy anorexia, pain, fever, jaundice, light (sound) -gefärbter chair, dark urine, increased liver enzymes (AST, bilirubin) Chronic jaundice, disappearing bile duct syndrome = (with elevated bilirubin, alkaline phosphatase and GGT), slightly elevated liver function tests (AST, bilirubin), ascites GGT Gamma-glutamyl transpeptidase. For the differential diagnosis of acute rejection reaction include viral hepatitis (eg., By infection with cytomegalovirus or Epstein-Barr virus, recurrent infections with hepatitis B, C or both), Calcineurininhibitortoxizität and cholestasis. If the clinical diagnosis is not clear, a percutaneous needle biopsy is performed. Suspicion of rejection is a treatment with iv performed corticosteroids; is the treatment ineffective (in 10-20% of cases), then offers itself as an alternative to anti-thymocyte globulin. If rejection does not respond to immunosuppressive therapy, the treatment of retransplantation. Hepatitis recurrence after transplantation in patients suffering prior to transplantation to an induced by hepatitis virus cirrhosis, contributes to immunosuppression recurrence of viral hepatitis. Hepatitis C occurs in almost all patients; usually viremia and infection are asymptomatic, but can cause an active hepatitis and cirrhosis. Risk factors for clinically significant re-infection may be associated with receiver: eg age, HLA type, and hepatocellular carcinoma donors: Eg age, obesity, prolonged ischemic time and living donor virus: high viral load, genotype 1B, does not respond to interferon Post procedural events: Immunosuppressive doses , acute rejection is treated with corticosteroids and cytomegalovirus the standard treatment for hepatitis is only marginally effective, although there is the hope of newer antiviral drugs (eg. as telaprevir) that improve the outcomes of patients with recurrent hepatitis C. Hepatitis B occurs in all patients, but is successfully treated with antiviral drugs; co-infected with hepatitis D appears to have a protective effect against recurrence. Other complications Early complications (within 2 months) in liver transplantation Primary nonfunction (z. B. ischemic anastomotic strictures, bile leakage, transition seal, open position on the T-tube-side) comprise from 1 to 5% biliary dysfunction in 15 to 20% portal vein thrombosis at <5% thrombosis of the hepatic artery at 3 to 5% (especially in young children or recipients of split grafts) Mycotic hepatic artery or pseudo aneurysm and rupture of the hepatic artery Typically, the symptoms and discomfort of early complications fever, hypotension and abnormal liver function. Diehäufigsten late complications intrahepatic or anastomotic biliary strictures with symptoms of cholestasis or cholangitis after liver transplantation with DCD transplants constrictions at about a quarter to a third of recipients are particularly common. Sometimes strictures can be extended endoscopic or percutaneous transhepatic cholangiography using a, a stent, or both. Often re-transplantation is eventually required. 90% (patients) and 82% (grafts) transplants from deceased donors:: Forecast At 1 year after liver transplantation, the survival rates living donor grafts are 86% (patients) and 82% (grafts) overall survival rate after 3 years: 79% (patients) and 72% (grafts) After 5 years: 73% (patients) and 65% (grafts) The survival rate is in chronic liver failure better than acute. It comes a year after the transplant to death, then the causes lie more in recurrent disease (eg. as cancer, hepatitis) than in post-transplant complications. Within 5 years after a transplant recurrent hepatitis C results in 15-30% of patients to cirrhosis. Liver disease with an autoimmune component (eg., Primary biliary cirrhosis, primary sclerosing cholangitis, autoimmune hepatitis) occur in 20-30% of cases within 5 years.

Health Life Media Team

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