The Boston Center for Liver Transplantation (BCLT). Initial experience of a new surgical consortium

Liver transplantation: Issues for the next 20 years

The growing numbers of potential transplant recipients on waiting lists is increasingly disproportionate to the supply of cadaveric donor organs. The hope for the next 20 years is that supply will satisfy demand. This requires both a reduction in indications for the procedure and an increase in the transplants performed. A multi-pronged approach is needed to increase cadaveric organ donation, generating enthusiasm for donation among both the general public and hospital staff. Accurate assessment of marginal grafts with stringent criteria known to predict graft function will diminish wastage of organs. Methods of rehabilitating marginal grafts during extracorporeal perfusion will increase organ availability. Supply of non-heart beating donors can be greatly expanded and protocols developed with ethical consent to optimize their initial function despite warm ischemia. Splitting livers that fulfill selection criteria, thus providing for two recipients, should be universally applied with acceptable incentives to those units who do not directly benefit. A proportion of recipients, though not those transplanted for autoimmune disease, will be spared the side-effects of immunosuppression thanks to immune tolerance. Protocols for close monitoring of those patients for rejection during treatment withdrawal must be carefully observed. In addition to gene therapy, it is highly likely that hepatocyte transplantation will replace orthotopic grafting in patients without cirrhosis, especially for inherited metabolic diseases. It is much more difficult to envisage that heterologous stem cell transplantation or xenotransplantation will have clinical impact in the next 20 years, although research in those areas has obvious long-term potential.

A follow up of 53 adult patients alive beyond 2 years following liver transplantation

Although hepatic transplantation is now a well-accepted treatment modality for end-stage liver diseases there are little detailed data on the clinical profile of patients who survive beyond 1 year following transplantation. The aim of this study was to develop a cross-sectional profile on 53 adults who have survived beyond 2 years following liver transplantation. These patients have been followed for a mean of 43.5 months (range 24-84) since the time of transplant. Nineteen patients had persisting liver enzyme abnormalities, 11 due to chronic viral hepatitis (seven hepatitis C virus, three hepatitis B virus), four due to biliary disease. Two had post severe rejection, one steatosis secondary to obesity while in one the aetiology was unclear. Nineteen (36%) of patients required anti-hypertensive medications. The median doses of Prednisone, Cyclosporin and Imuran were 7.5, 300 and 50 mg daily, respectively. The mean serum creatinine was 117 +/- 27 mumol/L. However 22 (41%) had an elevated serum creatinine (> 120 mumol/L) but in only seven was the serum creatinine > 150 mumol/L. Fourteen (26%) of patients were obese (body mass index > 30) whilst 46% had a higher than recommended serum cholesterol (mean level 5.6 +/- 1.5 mumol/L). There has only been one case of internal malignancy (lymphoma) although 19 patients attend regular dermatological review for skin cancer surveillance. Forty-eight patients had a Karnofsky Score > 80. In conclusion, the vast majority of these patients have excellent clinical function but some caution is required with respect to renal function, hypertension, obesity and mild hypercholesterolaemia.(ABSTRACT TRUNCATED AT 250 WORDS)

Selection of patients for liver transplantation

Liver transplantation is now available world-wide. It plays an important role in the treatment of irreversible acute and chronic liver disease (CLD). Selection of patients for liver transplantation is subject to many factors including economic, cultural, availability of donor organs and degree of illness. This article looks at seven general considerations for recipients of liver transplantation. As well, disease-specific criteria are investigated and include such areas as cirrhosis due to chronic hepatitis B virus (HBV), hepatitis C virus (HCV) positive cirrhosis, fulminant hepatic failure (FHF), malignancy, alcoholic liver disease (ALD), metabolic conditions and Budd-Chiari syndrome. If hepatic transplantation survival rates were to approach 95%, the relative risk ratio between transplantation and conservative therapy would increase. At present an 80% 1-5 year survival rate following transplantation should be expected.

Ammonia elimination as a rapid index of viability in liver grafts in dogs

We examined intraoperative changes in blood ammonia levels and the correlation with graft viability in orthotopic liver transplantation (OLTx) in 29 dogs. Blood ammonia levels following total hepatectomy were examined using five dogs. These levels immediately following hepatectomy (15 min) were significantly higher (212 +/- 29 micrograms/dl) over values noted before hepatectomy (93 +/- 11 micrograms/dl, P less than 0.05). OLTx was performed using the cuff technique. The animals were divided into two groups: Group A (n = 6 pairs), OLTx with a nonpreserved fresh graft; Group B (n = 6 pairs), OLTx with an 8-hr preserved graft with lactated Ringer (4 degrees C). In both groups, the blood ammonia levels before the surgery and at the anhepatic phase data did not differ; however, following reperfusion, the levels in Group B were significantly higher (211 +/- 26 at 15 min, 200 +/- 50 micrograms/dl at 30 min) than those in Group A (121 +/- 10 at 15 min; P less than 0.01, 109 +/- 9 micrograms/dl at 30 min; P less than 0.05). The blood ammonia level highly correlated with adenosine triphosphate contents in the liver tissue, blood level of lactic acid, and amount of bile output, all pertinent indicators of the graft viability. Thus, the potential to eliminate ammonia immediately after reperfusion can serve as an indicator of graft viability. The intraoperative monitoring of blood ammonia levels can be included in management guidelines in cases of liver transplantation.

Liver transplantation for variceal hemorrhage

At the present time, liver transplantation must be considered among the treatment options for patients with variceal hemorrhage. For a significant percentage of variceal bleeders throughout the world, however, transplantation is not a viable option either because the patient is not an appropriate transplant candidate or because of the etiology of the patient's portal hypertension. Sclerotherapy and portosystemic shunts remain the mainstay of therapy for these patients. The survival rates with liver transplantation are superior to those reported for other therapies for variceal hemorrhage in patients who have moderate or severe liver disease in addition to variceal hemorrhage. Child's C patients whose variceal hemorrhage is controlled medically should be evaluated for transplantation and receive chronic sclerotherapy while they wait on the transplant list. If the variceal hemorrhage cannot be controlled medically in a transplant candidate, then the patient should undergo an emergency shunt procedure. The shunt of choice is a large-bore H-graft mesocaval or mesorenal shunt. This shunt effectively controls the acute hemorrhage, is relatively simple to perform, does not adversely impact on the subsequent liver transplant, and can simply be ligated after the transplant is completed. Patients who experience variceal hemorrhage as the only manifestation of their liver disease should be treated initially with endoscopic sclerotherapy. For that small group of patients who are either not candidates for sclerotherapy or who rebleed despite sclerotherapy, the choice of shunt or transplantation is presently a difficult one, because both therapies provide excellent results in this group of patients. The choice of therapy should be made on an individual basis and only after consultation with both transplant and shunt surgeons. If a shunt is chosen, we prefer the DSRS because it maintains hepatic portal perfusion in many patients and does not require dissection of the porta hepatis. The management of patients with a prior portosystemic shunt at the time of transplantation depends on the type of shunt and the duration of time between the shunt and the transplant. Shunts not involving the hepatic hilum have little adverse impact on the performance of the transplant. There are insufficient data to assess accurately the effect of a prior portacaval shunt on the transplant. However, our clinical experience and that of other transplant groups indicate that the transplantation of these patients is technically more difficult than that of patients with shunts not involving the hilum. With the availability of other shunting procedures that do not involve extensive dissection of the hepatic hilum, there is little role for either end-to-side or side-to-side portacaval shunts in patients who are potential liver transplant candidates.(ABSTRACT TRUNCATED AT 400 WORDS)

Size reduction of the donor liver is a safe way to alleviate the shortage of size-matched organs in pediatric liver transplantation

The development of pediatric liver transplantation is considerably hampered by the dire shortage of small donor organs. This is a very sad situation because in most experienced centers, liver replacement can offer a long-term hope of survival of more than 70% in a growing variety of pediatric liver disorders. The reported experience with 54 reduced-size grafts on a total of 141 transplants performed in 117 children between 1984 and 1988 demonstrates that the technique of reduced-size liver transplantation not only allows long-term survival but, in fact, offers the same survival hope with the same quality of liver function, regardless of the child's age and clinical condition. The prominent feature of our experience with the reduced liver concerns its deliberate use for elective cases. Seventy-seven per cent of the 30 children who electively received a reduced liver were alive 1 year after transplantation, as were 85% of the 62 children who received a full-size graft. There is no difference in the long-term survival rate of patients who received elective grafts, which is in the range of 75% with both techniques.

Liver transplantation

Liver transplantation has become an established form of therapy for patients with almost any type of irreversible and severe liver disease. The remarkable success of liver transplantation has resulted from recent advances in immunosuppressive therapy, surgical techniques, and patient selection. Additional progress has been made in the management of the complex postoperative medical complications that may occur. Indeed, liver transplantation has contributed significantly to an improved quantity and quality of life for many patients with liver disease.

Experience with transplantation in the treatment of liver cancer

Thirteen patients with hepatic tumors, from the Boston Center for Liver Transplantation, have been transplanted among a total of 169 recipients. Ten were transplanted primarily for tumor, while three other patients harbored incidental tumors. Two perioperative deaths occurred (15%). Eight patients had hepatocellular carcinoma, one hepatoblastoma and four bile duct (Klatskin) tumors. Two of the bile duct cancers recurred with patient deaths at 9 and 10 months. The remaining nine patients are alive from between 1 month and 36 months postoperatively. A selected review of the literature allowed analysis of follow-up on 185 patients transplanted for tumor. Overall, the proportion of patients transplanted for tumor was 16%. Fifty-two percent of patients had hepatocellular carcinomas (HCC), 24% cholangiocarcinomas, 10% other primary liver tumors, and 14% metastatic hepatic tumors. Median survival for HCC was 1 year; 90-day mortality was 30%. Actuarial survival for 1, 2 and 3 years was 49%, 37% and 30% respectively. Fibrolamellar HCC and incidental HCC had significantly better results than other HCC. Tumor recurrence was present in 72% of autopsies after 90 days. Transplantation for HCC has satisfactory results in selected patients and may be improved by adjuvant chemotherapy. The median survival with cholangiocarcinomas was 8 months; 90-day mortality was 40%. Actuarial survival for 1 year was 36%. Recurrence was present in 100% of autopsies after 90 days. Survival after transplantation for this tumor was similar to that observed in patients not undergoing surgical treatment. Median survival for 18 other primary hepatic tumors was 16 months. Transplantation in carefully selected patients with these other primary tumors appears warranted. Although experience overall with transplantation for metastatic disease has been relatively unfavorable, each histological type must be considered independently.

Complications requiring operative intervention after orthotopic liver transplantation

Survival rates after liver transplantation continue to improve, but the postoperative morbidity in these patients remains significant. The clinical courses of 96 consecutive patients who received transplants were reviewed retrospectively. Forty-two patients experienced complications requiring surgical intervention. These complications were primarily related to biliary tract reconstruction, bowel complications, and septic complications. None of the factors examined, except a second transplant procedure, proved helpful in identifying those patients most likely to experience surgical complications; however, a risk factor scoring system was found to accurately identify that group of patients at highest risk of dying in the postoperative period. Only 2 of 21 deaths could be attributed directly to the surgical complication. We believe that a policy of prompt, aggressive surgical intervention, coupled with careful tailoring of immunosuppression to both the patient and the clinical situation, can lead to a low mortality rate in patients who require reoperation.

Decreased loss of liver adenosine triphosphate during hypothermic preservation in rats pretreated with glucose: implications for organ donor management

Recent studies of human donor livers indicate an association between ex vivo hepatocellular adenosine triphosphate and posttransplant graft function. To test the hypothesis that prior glucose loading of donor liver would optimize its adenosine triphosphate production and adenylate energy charge during ex vivo organ preservation, adult male rats were randomized to receive either intravenous dextrose or saline for 44 h. After this infusion, a liver lobe was exposed and freeze-clamped (time 0). The remaining liver was quickly flushed, excised, and stored in Collins' II solution at 2 degrees C for 8 h. Additional lobes were freeze-clamped at 1, 4, and 8 h. Liver adenosine triphosphate, total nucleoside triphosphates, and energy charge losses were significantly reduced in the dextrose-treated rats in comparison with saline-treated rats during the first 4 h of preservation. Although the livers from rats receiving intravenous dextrose were able to generate lactate, their glycogen stores were not utilized appreciably, suggesting that exogenous glucose served as a substrate for anaerobic glycolysis. Unesterified choline levels of the fasted rat livers were significantly higher than those from the rats receiving intravenous dextrose by the first hour, indicative of increased membrane breakdown. These results indicate that prior infusion of glucose enhances the capacity of the ex vivo liver, presumably through the induction and stabilization of key glycolytic enzymes, to anaerobically generate adenosine triphosphate. Administration of glucose to liver donors before organ procurement may improve post-transplant graft function by reducing the loss of hepatocellular energy, retarding membrane damage, and fostering glycogen storage for use in the early postoperative period.

The acute vanishing bile duct syndrome (acute irreversible rejection) after orthotopic liver transplantation

The acute vanishing bile duct syndrome can be defined as an irreversible, rejection-related condition that affects hepatic allografts within 100 days after orthotopic liver transplantation and whose presence requires retransplantation. We have observed the acute vanishing bile duct syndrome in 5 of 48 consecutive patients (approximately 10%) who underwent orthotopic liver transplantation. In 4 cases, the condition progressed relentlessly within approximately 7 to 11 weeks after orthotopic liver transplantation from mild rejection to severe rejection to acute vanishing bile duct syndrome. A fifth patient had severe rejection in the first week and required retransplantation after 17 days because of thrombotic venoocclusive disease complicating the acute vanishing bile duct syndrome. Clinically, signs of impending acute vanishing bile duct syndrome included abrupt onset of fever and jaundice and marked elevation of serum bilirubin and alkaline phosphatase levels which persisted despite antirejection treatment. Biopsy specimens revealed destructive cholangitis (rejection cholangitis), ductopenia, and, if retransplantation was delayed, presence of noninflammatory, "burnt-out" portal tracts without bile ducts. We recommend to base the diagnosis of acute vanishing bile duct syndrome on documentation of severe ductopenia in at least 20 portal tracts which may require several consecutive needle biopsies. Rejection arteriopathy which was found in 3 of our 5 cases might have been another important diagnostic clue but could not be recognized prior to retransplantation. The pathogenesis of acute vanishing bile duct syndrome is not clear; until the condition had manifested itself, we found no qualitative differences between acute reversible and irreversible rejection.(ABSTRACT TRUNCATED AT 250 WORDS)

Survival from hepatic transplantation. Relationship of protein synthesis to histological abnormalities in patient selection and postoperative management

Forty-one patients, all in end stage hepatic failure, underwent 46 liver transplantations with a long-term survival rate of 63%. Six patients died of uncontrollable bleeding due to primary graft malfunction at or immediately after operation. Nine died early or late with overwhelming infection. In addition to clinical assessment, needle liver biopsy, central plasma clearance rate of amino acids (CPCR-AA), and routine "liver function tests" were employed to aid in selection of patients for transplantation and for guidance in postoperative management. Although liver biopsies usually afforded an exact diagnosis, neither they nor the routine liver function tests quantitated the extent to which hepatocyte function was impaired. CPCR-AA, which measures the rate of amino acid uptake by the liver and other central tissues for oxidation, gluconeogenesis, and protein synthesis was 91 +/- 9 ml/M2/min in the preoperative transplant group. This compares with a value of 97 +/- 16 in a previously studied series of cirrhotics who died following other forms of surgery and a CPCR-AA of 220 +/- 26 ml/m2/min in those who survived. In addition, the preoperative CPCR-AA was found to correlate with the in vitro hepatic protein synthetic rate of slices from the resected recipient liver (r = 0.72, p less than 0.02). After operation, serial hepatic needle biopsies were classified by histology into four grades of injury, ranging from normal liver transplant (Grade I) to mild hypoxic or rejection injury (Grade II), viral hepatitis (Grade III), and severe hypoxic or rejection injury (Grade IV). Significant relationships of the histological grades to ultimate mortality, CPCR-AA, and prothrombin times were found. CPCR-AA and prothrombin time correlate inversely (r = 0.57, p less than 0.001), further demonstrating the relationship of CPCR-AA to protein synthesis of clotting factors. These patterns of posttransplant response were delineated by serial CPCR-AA values. "Early" responders had values over 290 ml/M2/min and all survived. Twelve patients with delayed response were characterized by values of 150 +/- 12, rising to over 200 ml/M2/min after 2 weeks. Two who failed to increase CPCR-AA died. In six "poor" responders, CPCR-AA with Grade IV injury remained below 110 ml/M2/min. All died except for one whose CPCR-AA subsequently rose following retransplantation. It is concluded that percutaneous hepatic needle biopsies and CPCR-AA measurements in combination are of proven value, not only in understanding the nature of injury and functional impairment of the liver, but are also important as guides to selection of patients and for their posttransplant management.