Liver transplantation in acute liver failure:A challenging scenario

Acute liver failure is a critical medical condition defined as rapid development of hepatic dysfunction associated with encephalopathy. The prognosis in these patients is highly variable and depends on the etiology, intervalbetween jaundice and encephalopathy, age, and the degree of coagulopathy. Determining the prognosis for this population is vital. Unfortunately, prognostic models with both high sensitivity and specificity for prediction of death have not been developed. Liver transplantation has dramatically improved survival in patients with acute liver failure. Still, 25% to 45% of patients will survive with medical treatment. The identification of patients who will eventually require liver transplantation should be carefully addressed through the combination of current prognostic models and continuous medical assessment. The concerns of inaccurate selection for transplantation are significant, exposing the recipient to a complex surgery and lifelong immunosuppression. In this challenging scenario, where organ shortage remains one of the main problems, alternatives to conventional orthotopic liver transplantation, such as living-donor liver transplantation, auxiliary liver transplant, and ABO-incompatible grafts, should be explored. Although overall outcomes after liver transplantation for acute liver failure are improving, they are not yet comparable to elective transplantation.     

Bioartificial liver support

Orthotopic liver transplantation is the only definitive therapy for patients with fulminant hepatic failure (FHF). However, due to shortage of organs, a large number of patients die before a liver can be procured for transplantation. In FHF the need for a liver is particularly urgent because of rapid deterioration in the patients' condition with the onset of cerebral edema and intracranial hypertension leading to irreversible brain damage. It is thus necessary to develop an extracorporeal liver support system to help maintain patients alive and neurologically intact until an organ becomes available for transplantation. Multiple attempts have been made, ranging from the use of plasma exchange to utilization of charcoal columns and extracorporeal devices loaded with liver tissue to develop liver support systems for treating patients with acute severe liver failure. None of these systems has achieved wide clinical use, and FHF due to multiple causes continues to be associated with significant morbidity and mortality. In this paper, the authors review the history of extracorporeal liver support for acute liver failure and discuss their experience with a hollow fiber bioartificial liver support system utilizing porcine hepatocytes in the treatment of patients with acute liver failure.     

Aetiology and outcome of acute liver failure

Background:

Acute liver failure (ALF) is a clinical syndrome characterized by the sudden onset of coagulopathy and encephalopathy. The outcome is unpredictable and is associated with high morbidity and mortality. We reviewed our experience to identify the aetiology and study the outcome of acute liver failure.

Methods:

A total of 1237 patients who presented with acute liver failure between January 1992 and May 2008 were included in this retrospective study. Liver transplantation was undertaken based on the King''s College Hospital criteria. Data were obtained from the units prospectively collected database. The following parameters were analysed: patient demographics, aetiology, operative intervention, overall outcome, 30-day mortality and regrafts.

Results:

There were 558 men and 679 women with a mean age of 37 years (range: 8–78 years). The most common aetiology was drug-induced liver failure (68.1%), of which 90% was as a result of a paracetamol overdose. Other causes include seronegative hepatitis (15%), hepatitis B (2.6%), hepatitis A (1.1%), acute Budd–Chiari syndrome (1.5%), acute Wilson''s disease (0.6%), subacute necrosis(3.2%) and miscellaneous (7.8%). Three hundred and twenty-seven patients (26.4%) were listed for liver transplantation, of which 263 patients successfully had the procedure (80.4%). The current overall survival after transplantation was 70% with a median follow-up of 57 months. After transplantation for ALF, the 1-year, 5-year and 10-year survival were 76.7%, 66% and 47.6%, respectively. The 30-day mortality was 13.7%. Out of the 974 patients who were not transplanted, 693 patients are currently alive. Among the 281 patients who died without transplantation, 260 died within 30 days of admission (26.7%). Regrafting was performed in 31 patients (11.8%), the most common indication being hepatic artery thrombosis (11 patients).

Conclusion:

Paracetamol overdose was the most common cause of acute liver failure. Liver transplantation, when performed for acute liver failure, has good long-term survival.     

Etiology and outcome of acute liver failure: experience from a liver transplantation centre in Montreal.

BACKGROUND: Acute liver failure is a rare condition in which massive liver injury is associated with the rapid development of hepatic encephalopathy. Although viral hepatitis and drug-induced liver injury are the most common causes, no specific etiology is found in a substantial proportion of cases reported from Europe and the United States. AIM: To determine the etiology and outcome of patients with acute liver failure in the authors' institution. PATIENTS AND METHODS: The charts of 81 consecutive patients admitted to Saint-Luc between 1991 and 1999 were reviewed. RESULTS: The etiology was viral in 27 cases (33.2%), toxic or drug-induced in 22 (27.2%), of unknown origin in 22 (27.2%) and due to various causes in 10 (12.3%) (autoimmune, vascular, cancer). Of the 81 patients, 16% survived without liver transplantation, and 84% died or underwent liver transplantation. Survival without liver transplantation differed according to the mode of presentation: the survival rate was 27% in patients with hyperacute liver failure, 7% in those with acute liver failure and 0% in those with subacute liver failure. Among the 38 patients who underwent liver transplantation, survival one year after transplantation was 71%. In the 30 patients who died without liver transplantation, the main causes of death were cerebral edema and sepsis. CONCLUSIONS: Acute liver failure is associated with a high mortality, and liver transplantation is the treatment of choice. In a significant proportion of cases, the etiology remains undetermined and is probably related to yet unidentified hepatotropic viruses.     

Urgent adult-to-adult right lobe living donor liver transplantation for acute liver failure; a single center experience from Turkey

BACKGROUND/AIMS: Acute liver failure is a fatal condition unless an urgent liver transplantation is performed. In countries like Turkey, because of limited availability of cadaveric allografts, living donors could be used as an organ source for acute liver failure. We report our single center experience. METHODOLOGY: Six adult-to-adult right lobe living donor liver transplantations have been performed for those patients admitted with fulminant liver failure between September 2000 and April 2004. RESULTS: The age of the patients ranged between 19 and 54 years. Etiology was fulminant hepatitis B in 4 patients, Wilson's disease in 1 patient, and unknown in 1 patient. Five of 6 patients survived and are currently alive and well with a mean 30 (2-46) months follow-up. None of the survivors had neurological sequela. One patient died because of sepsis 2 months after transplantation. There was no donor mortality. CONCLUSIONS: Adult-to-adult right lobe living donor liver transplantation seems to be an effective and safe option for patients with fulminant liver failure, especially in countries with a limited number of available cadaveric donors.     

Combined transplantation of the heart, lung, and liver

Combined transplantation of the heart, lung, and liver may be indicated in patients with either end-stage respiratory failure complicated by advanced liver disease or end-stage liver failure complicated by advanced lung disease. A retrospective review of nine patients who underwent combined heart-lung-liver transplantation in Cambridge (1986-99) was carried out. The 1-year and 5-year actuarial survival was 56% and 42%, respectively. Combined heart-lung-liver transplantation is a feasible option for a few patients and has a 5-year survival similar to heart-lung transplantation but with a lower incidence of acute and chronic rejection.     

Acute liver failure

Acute liver failure (ALF) is defined as hepatic encephalopathy complicating acute liver injury. The most common etiologies are acute viral hepatitis A and B, medication overdose (e.g., acetaminophen), idiosyncratic drug reactions, ingestion of other toxins (e.g., amanita mushroom poisoning), and metabolic disorders (e.g., Reye's syndrome). Despite advances in intensive care management, mortality continues to be high (40-80%) and is partly related to ALF's complications, such as cerebral edema, sepsis, hypoglycemia, gastrointestinal bleeding, and acute renal failure. Several prognostic models have been developed to determine which patients will spontaneously recover. Treatment is directed at early recognition of the complications and general supportive measures. The only proven therapy for those who are unlikely to recover is liver transplantation. Therefore, recognition of ALF is paramount, and urgent referral to a transplant center is critical to assess transplantation status.     

Therapeutic plasma exchange in liver failure

The multi-organ failure syndrome associated with acute and acute-on-chronic liver failure (ACLF) is thought to be mediated by overwhelming systemic inflammation triggered by both microbial and non-microbial factors. Therapeutic plasma exchange (TPE) has been proven to be an efficacious therapy in autoimmune conditions and altered immunity, with more recent data supporting its use in the management of liver failure. Few therapies have been shown to improve survival in critically ill patients with liver failure who are not expected to survive until liver transplantation (LT), who are ineligible for LT or who have no access to LT. TPE has been shown to reduce the levels of inflammatory cytokines, modulate adaptive immunity with the potential to lessen the susceptibility to infections, and reduce the levels of albumin-bound and water-bound toxins in liver failure. In patients with acute liver failure, high volume TPE has been shown to reduce the vasopressor requirement and improve survival, particularly in patients not eligible for LT. Standard volume TPE has also been shown to reduce mortality in certain sub-populations of patients with ACLF. TPE may be most favorably employed as a bridge to LT in patients with ACLF. In this review, we discuss the efficacy and technical considerations of TPE in both acute and acute-on-chronic liver failure.     

Auxiliary versus orthotopic liver transplantation for acute liver failure. EURALT Study Group. European Auxiliary Liver Transplant Registry

BACKGROUND/AIMS/METHODS: We report 1-year results after auxiliary liver transplantation for acute liver failure in a cohort of 47 patients transplanted in 12 European centers as compared with those of 384 consecutive patients undergoing orthotopic liver transplantation for acute liver failure in the Eurotransplant area. RESULTS: One-year patient survival resp. retransplant-free patient survival did not differ between orthotopic (61%, 232/384 resp. 52%, 200/384) and auxiliary liver transplantation (62%, 29/47 resp. 53%, 25/47). One-year patient survival resp. retransplant-free patient survival after auxiliary partial orthotopic liver transplantation was 71% (25/35) resp. 60% (21/35), not significantly different from orthotopic liver transplantation (61%, 232/384 resp. 52%, 200/384), while both transplantation techniques had better 1-year patient survival resp. retransplant-free patient survival than after heterotopic auxiliary liver transplantation (33%, 4/12) (p < 0.05). Primary nonfunction was more frequent after heterotopic auxiliary liver transplantation (3/12, 25%) than after orthotopic liver transplantation (21/384, 5.5%), while the incidence did not differ between orthotopic liver transplantation and auxiliary partial orthotopic liver transplantation (3/35, 8.5%). Portal vein thrombosis was more frequent after both heterotopic auxiliary liver transplantation (5/12, 42%) and auxiliary partial orthotopic liver transplantation (5/35, 14%) than after orthotopic liver transplantation (2/384, 0.5%) (p < 0.001). Of the patients, 65% (17/26) surviving auxiliary liver transplantation for 1 year without retransplantation by orthotopic liver transplantation were free of immunosuppression within 1 year, compared with none of the patients transplanted by orthotopic liver transplantation (p < 0.01). CONCLUSIONS: Auxiliary liver transplantation, especially auxiliary partial orthotopic liver transplantation, offers an advantage over orthotopic liver transplantation in acute liver failure in terms of a chance of a life free of immunosuppression, apparently without jeopardizing chances of survival. Reduction of the incidence of primary nonfunction and vascular complications should be a focus of research in auxiliary liver transplantation. These findings need to be confirmed in a prospective study.     

Current indications and contraindications for liver transplantation

Survival rates after liver transplantation have improved steadily because of earlier referral and timely evaluation, judicious patient selection, improved surgical techniques, superior immunosuppressive regimens, and effective prevention of perioperative opportunistic infections. Indications and contraindications for liver transplantation are undergoing constant modifications with the goal of improving survival and functional status of patients who have end-stage liver disease or acute liver failure. Potential candidates for liver transplantation should meet minimal listing criteria and not have contraindications to liver transplantation. Currently, the Model for End-stage Liver Disease score is used for organ allocation, but it may have future application in patient-selection criteria.     

背驮式肝移植治疗急性肝衰竭15例

目的探讨肝移植治疗急性肝衰竭（ALF）的临床疗效，总结移植前处理、手术时机的选择以及术中关键技术应用的经验。方法回顾性分析了1999年9月2006年2月采用背驮式肝移植治疗15例ALF患者的临床资料。结果患者均获随访，术后1年生存率87％（13／15）。其中2例急性肝衰竭型威尔逊氏病患者术后角膜K—F环消失，血清铜蓝蛋白恢复正常。1例术后第11天死于多系统器官功能衰竭，1例患者术后第6天死于严重肺部感染，其余11例HBsAg转阴。结论肝移植是治疗ALF的有效方法，能提高ALF患者的生存率；年龄不应作为ALF患者肝移植的禁忌证；充分的术前准备和恰当的移植时机选择以及术中关键技术的使用是提高术后生存率的关键。     

Acute Liver Failure

Acute liver failure is a rare but often catastrophic illness affecting the liver and multiple organ systems. Patients with acute liver failure require a multidisciplinary approach for adequate management. With improved critical care and the availability of liver transplantation, survival has significantly improved. Hepatic encephalopathy, cerebral edema and infections are the most common complications of acute liver failure. The evaluation requires a diligent search for a specific etiology of the liver failure, since certain causes may respond well to specific pharmacological therapies. Acetaminophen and non-acetaminophen drug-induced hepatotoxicity account for more than 50% of cases of acute liver failure. Assessment of prognosis frequently (at least on a daily basis) by using various prognostic tools, allows the treating team to decide whether or not to proceed with urgent liver transplantation. Artificial liver support devices are still in evaluation and not ready for use in clinical practice. While it is determined whether or not there is sufficient hepatic regeneration, the care of the patient with acute liver failure revolves around managing the dysfunction of multiple extra hepatic systems.     

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 receipients 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 surivival 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.     

Acute liver failure in children

The management of children with acute liver failure mandates a multidisciplinary approach and intense monitoring. In recent years, considerable progress has been made in developing specific and supportive medical measures, but clinical studies have mainly concerned adult patients. There are no specific medical therapies, except for a few metabolic diseases presenting with acute liver failure. Liver transplantation still remains the only definitive therapy in most instances. Recent clinical studies suggest that hepatocyte transplantation may be useful for bridging patients to liver transplantation, for providing metabolic support during liver failure and for replacing liver transplantation in certain metabolic liver diseases.     

Artificial extracorporeal liver support therapy in patients with severe liver failure

Severe liver failure is common and carries a high mortality risk in patients with both acute and acute-on-chronic liver failure. The failing liver constitutes a medical emergency, and in many cases liver transplantation is the only definite treatment. Extracorporeal liver support can be employed as a strategy for bridging to transplantation or recovery. This article focuses on options for artificial (nonbiological) extracorporeal treatment: single-pass albumin dialysis, fractionated plasma separation and adsorption (Prometheus^®) and the molecular adsorbent recirculatory system. Their different principles, potential advantages and indications are discussed. Despite proven biochemical efficacy, there are little data regarding clinical end points. Thus far, molecular adsorbent recirculatory system therapy in acute and acute-on-chronic liver failure showed no survival benefit compared with standard medical therapy. Prometheus therapy showed reduced mortality in subgroups of higher severity of disease compared with standard medical therapy. Nevertheless, the value of extracorporeal liver support remains to be corroborated by further clinical studies that include the optimal timing, mode, intensity and duration of this treatment.     

Emergency liver transplantation for fulminant liver failure in infants and children.

We report our results with orthotopic liver transplantation in children with fulminant liver failure. Thirty-five children with fulminant liver failure were evaluated for liver transplantation. The main causes of liver failure were viral hepatitis (54.2%), drug-induced liver injury (14.2%) and Wilson's disease (11.4%). Children were considered as candidates for liver transplantation only if hepatic encephalopathy was associated with a decrease in the level of factor V to below 25%. Seven children (20%) did not meet this criterion and recovered spontaneously. Six children (17.1%) had contraindications for liver transplantation and died. In three of these six children, contraindications included irreversible brain damage at the time of admission. Twenty-two children (62.8%) met the criteria for liver transplantation and were placed on the emergency transplant list. Three of them died awaiting grafts. Nineteen children underwent liver transplantation; 13 of them (68.4%) are alive without sequelae, after 6 mo to 4 yr of follow-up, at this writing. Four of the children who died after surgery had severe encephalopathy on admission that did not improve after liver transplantation. In conclusion, emergency liver transplantation appears to be an effective treatment for children with fulminant liver failure. Nevertheless, irreversible brain damage developed in 10 patients, and they died before or after surgery. We postulate that many of these deaths could have been avoided if children had been transferred to a liver transplantation facility and had undergone transplantation earlier. We emphasize that children with acute liver failure should be transferred to a center that performs liver transplantation before the development of hepatic encephalopathy.     

Pretransplantation clinical status and outcome of emergency transplantation for acute liver failure

Emergency transplantation for acute liver failure has a significantly inferior outcome than transplantations performed for elective indications. The severity of the pretransplantation clinical illness in this group will contribute to the reduced patient survival. We have reviewed the outcome of our first 100 consecutive adult patients who received transplants for acute liver failure and have evaluated and determined which recipient clinical parameters present on admission and at transplantation act as risk factors in early posttransplantation outcome. In patients who received transplants for nonacetaminophen-induced liver failure (n = 79), no static variable determinable on admission (including age, sex, year of transplantation, hospital admission to transplantation period, and fulminant or late-onset presentation) other than cause was predictive of 2-month patient survival. Fulminant Wilson's disease and idiosyncratic drug reactions with 2-month survival rates of 100% and 12.5%, respectively, had significantly different outcomes from other causes. By the time of transplantation, of four dynamic variables significant in a univariate analysis (serum creatinine, encephalopathy grade, Apache 111 and organ system failure scores, and P values <.05), only the creatinine level was an independent variable in a stepwise logistic regression for 2-month survival (r = .33). In patients who received transplants for acetaminophen hepatotoxicity (n = 21), overdose to hepatectomy period was the only significant static variable, with no parameter predictive of outcome present on admission. Of two dynamic variables that were significant at transplantation (serum bilirubin and Apache 111 score, P < .05) only the latter parameter was an independent variable in the regression model (r = .51). Selection of candidates experiencing acute liver failure for transplantation depends on assessment of both the prognosis of the primary hepatic illiness on admission and, for a successful outcome, the clinical status at the time of proposed grafting.     

Determinants of early mortality in patients with decompensated chronic hepatitis B treated with antiviral therapy

BACKGROUND & AIMS: Chronic hepatitis B is a leading cause of death worldwide. To identify patients who might require urgent liver transplantation despite antiviral therapy, we investigated the determinants of early mortality in a large cohort of patients with decompensated chronic hepatitis B treated with lamivudine. METHODS: One hundred fifty-four North American patients with decompensated chronic hepatitis B received lamivudine for a median of 16 months. Univariate and multivariate Cox regression modeling was used to develop a model of 6-month mortality. RESULTS: A biphasic survival pattern was observed, with most deaths occurring within the first 6 months of treatment (25 of 32, 78%) because of complications of liver failure. The estimated actuarial 3-year survival of patients who survived at least 6 months was 88% on continued treatment. In multivariate modeling, elevated pretreatment serum bilirubin and creatinine levels as well as the presence of detectable hepatitis B virus (HBV) DNA (by the bDNA assay) pretreatment were significantly associated with 6-month mortality. An equation approximating the probability of early mortality was developed from these variables. CONCLUSIONS: Our data demonstrate a distinct alteration in the slope of the survival curve after 6 months of lamivudine treatment for decompensated chronic hepatitis B. An equation consisting of 3 widely available pretreatment laboratory parameters was developed that can be used to predict the likelihood of early death in patients receiving lamivudine for decompensated chronic hepatitis B. These observations may help identify patients who can be stabilized with suppressive antiviral therapy vs. those who require urgent liver transplantation.     

Parvovirus B19 induced hepatic failure in an adult requiring liver transplantation

Parvovirus B19 induced acute hepatitis and hepatic failure have been previously reported, mainly in children. Very few cases of parvovirus induced hepatic failure have been reported in adults and fewer still have required liver transplantation. We report the case of a 55-year-old immunocompetent woman who developed fulminant hepatic failure after acute infection with Parvovirus B19 who subsequently underwent orthotopic liver transplantation. This is believed to be the first reported case in the literature in which an adult patient with fulminant hepatic failure associated with acute parvovirus B19 infection and without hematologic abnormalities has been identified prior to undergoing liver transplantation. This case suggests that Parvovirus B19 induced liver disease can affect adults, can occur in the absence of hematologic abnormalities and can be severe enough to require liver transplantation.     

Clinical heterogeneity in autoimmune acute liver failure

AIM: To describe the outcome and prognosis in a cohort of patients with acute liver failure due to autoimmune hepatitis without liver transplantation. METHODS: A retrospective trial was conducted in 11 patients with acute liver failure due to autoimmune hepatitis who attended the Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubiran. Demographic, biochemical and severity indexes, and treatment and outcome were assessed. RESULTS: Among the 11 patients, with a median age of 31 years, 72% had inflammatory response syndrome, and six patients received corticosteroids. The mortality rate within four weeks was 56%, and the one-year survival was 27%. In the survivors, severity indexes were lower and 83% received corticosteroids. CONCLUSION: We observed a relatively high survival rate in patients with acute liver failure due to autoimmune hepatitis. This survival rate could be influenced by severity of the disease and/or use of corticosteroids.