Liver transplantation for fulminant hepatic failure: experience with more than 200 patients over a 17-year period

Liver Transplantation for Fulminant Hepatic Failure Without Venovenous Bypass and Without Portacaval Shunting

Preservation of the caval vein during liver transplantation (OLT) has gained wide acceptance but portosystemic bypass or temporary portocaval shunt is still believed to be indicated in patients with fulminant hepatic failure. Herein we have described our initial experience with piggyback OLT without venovenous bypass and without portocaval shunting in five such patients. Division of the portal vein was always delayed until the native liver was completely dissected off the caval vein. The donor hepatic artery was anastomosed to the recipient aorta via an iliac interposition graft placed in the supraceliac position in two and at an infrarenal site in three patients. The ahepatic phase urinary output was low in the two patients in whom we applied supraceliac cross-clamping of the aorta. The mean ahepatic phase was 53 (45 to 67) minutes in four recipients who remained hemodynamically stable throughout surgery and prolonged to 5 hours in one patient due to a complicated supraceliac aortic anastomosis. Its repair resulted in hemodynamic instability, multiorgan failure, and death at 4 days following OLT. Four (80%) patients are alive in good condition with normal liver function after a mean of 12 (5 to 25) months of follow-up. In summary, liver transplantation for fulminant hepatic failure may be safely performed without venovenous bypass and without temporary portocaval shunting if the ahepatic phase is minimized and portal flow to the liver maintained up to the moment of hepatic excision. Arterial anastomosis with the supraceliac aorta prolongs the ahepatic phase and may impair kidney function: therefore, it should be avoided in these patients.

Bioartificial liver systems: current status and future perspective

Because the liver is a multifunctional and a vital organ for survival, the management of acute liver failure requires the support of a huge number of metabolic functions performed by the organ. Many early detoxification-based artificial liver techniques failed to treat the patients owing to the inadequate support of the many essential hepatic functions. For this reason, a bioartificial liver (BAL) comprising of viable hepatocytes on a mechanical support is believed to more likely provide these essential functions than a purely mechanical device. From 1990, nine clinical studies of various BAL systems have been reported, most of which utilize a hollow fiber technology, and a much larger number of various BAL systems have been suggested to show an enhanced performance. Safety issues such as immunological reactions, zoonosis and tumorgenicity have been successfully addressed for regulatory approval, but a recent report from a large-scale, randomized, and controlled phase III trial of a leading BAL system (HepatAssist) failed to meet our expectation of efficacy in terms of the overall survival rate. In this paper, we review the current BAL systems actively studied and discuss critical issues such as the hepatocyte bioreactor configuration and the hepatocyte source. On the basis of the insights gained from previously developed BAL systems and the rapid progress in stem cell technology, the short-term and long-term future perspectives of BAL systems are suggested.

Moderate hypothermia therapy for acute liver failure in rats before liver transplantation

AIM: To observe the effect of moderate hypothermia on the donated livers in rats with acute liver failure (ALF) before liver transplantation.

METHODS: ALF rats model were established by hepatectomy and hepatic devascularization. In situ liver transplantations were carried out for hypothermia treated group (35.0ºC) and the control group (37.5ºC) 12 h after the transplantation. Blood and tissue samples were collected just before and 6 or 24 h after transplantation. The concentrations of TNF-α were compared before and after the transplantation. The content of malondialdehyde (MDA) and the apoptotic rate of hepatic cells after the transplantation were observed. The apoptotic rate and MDA contents in donated liver were also assayed. The morphological changes of liver tissues were observed under microscope.

RESULTS: In the hypothermia treated group, the concentrations of TNF-α before and after the transplantation were significantly lower than those in the control group (19.3±5.9 vs 43.4±9.0 µg/L, t= 5.008, P = 0.007; 6 h, 97.7±18.3 vs 137.1±23.3 µg/L, t = 9.471, P = 0.001); the MDA contents and apoptotic rate after transplantation were also significantly lower than those in the control group (407.1±49.4 vs 598.2±61.8 nmol/L, t = 34.46, P = 0.001; 18.3±3.9% vs 23.6±4.3%, t = 29.63, P = 0.001).

CONCLUSION: Moderate hypothermia can decrease TNF-α level and relieve the damages of the donated liver in rats with ALF.

[Acute liver failure in a hospital with a liver transplantation program]

INTRODUCTION

Acute hepatic failure (AHF) is an uncommon entity but with high mortality. Liver transplantation has improved prognosis but is an aggressive treatment with high risk. Currently, there are no accurate criteria to differentiate between irreversible AHF and the possibility of hepatic regeneration. The aim of this study is to review the clinical characteristics indicating transplantation and the outcome of AHF in patients at our institution.

PATIENTS AND METHOD

Descriptive and retrospective study of cases of AHF at our institution in the last 3 years.

RESULTS

Eleven patients were studied. Mortality was lower in transplant recipients (23%; 2 out of 8) than in non-transplanted patients (67%; 2 out 3). Hepatic regeneration occurred in one patient. Overall mortality was 36% with a perioperative mortality of 13%.

CONCLUSION

The indication of hepatic transplantation in patients with a poor prognosis, early stage acute liver failure, and a low grade of encephalopathy, and prior to the development of multiorgan failure could improve the results of transplantation and reduce perioperative mortality.

Development of a scaled up liver device incorporating cryo-preserved pig liver micro-organs

BACKGROUND/AIMS

Currently there is no effective therapy for most patients with fulminant or end stage liver disease.

METHODS

Pig liver micro-organs (LMOs), which preserve liver micro-architecture and ensure a maximal 150-200mum distance from a source of nutrients and gases have been prepared and a method to cryo-preserve them has been developed. A new scaled-up extra-corporeal liver device termed aLIVE-H in which LMOs are exposed to liver-like hemodynamic conditions has also been developed. The purpose of this work is to test the safety and function of cryo-preserved LMOs and how the hemodynamic properties of the scaled up aLIVE device affect their function.

RESULTS

Pig LMOs in aLIVE-H, transcribe albumin and Factor V at similar levels, irrespective of their position within the bioreactor, indicating that the hemodynamic features of the aLIVE-H device allow for homogeneous plasma distribution and proper function at different locations. Cryo-preserved LMOs transcribe albumin and Factor V at levels comparable to those transcribed by a normal pig liver. Connecting the aLIVE-H bioreactor to normal pigs did not affect key blood components and biochemical parameters.

CONCLUSIONS

An extra-corporeal liver device aLIVE-H which imitates the hemodynamic and functional properties of the normal liver and incorporates cryo-preserved LMOs has been developed and characterized. aLIVE-H was found to perform key synthetic liver functions.

Population-based epidemiology of intensive care: critical importance of ascertainment of residency status

INTRODUCTION

Few studies evaluating the epidemiology of critical illness have used strict population-based designs that exclude subjects external to the base population. The objective of this study was to evaluate the potential effects of inclusion of nonresidents in population-based studies in intensive care.

METHODS

A population-based cohort study including all adults admitted to Calgary Health Region (CHR) multidisciplinary and cardiovascular surgical intensive care units (ICUs) between 1 May 1999 and 30 April 2003 was conducted. A comparison of patients resident and nonresident in the base population was then performed.

RESULTS

A total of 12,193 adult patients had at least one admission to an ICU; 7767 (63.7%) were CHR residents, for an incidence of 263.7 per 100,000 per year. Male CHR residents were at significant increased risk for ICU admission as compared with females (330.5 per 100,000 versus 198.2 per 100,000; relative risk, 1.67; 95% confidence interval, 1.59-1.74; P < 0.0001), as were CHR residents aged 65 years and older as compared with younger patients (1719.9 per 100,000 versus 238.7 per 100,000; relative risk, 7.21; 95% confidence interval, 6.95-7.47; P < 0.0001). The mortality rate was significantly lower among non-CHR residents (12.7%) as compared with CHR residents (20.0%; P < 0.0001). Logistic regression modeling identified CHR residency as an independent risk factor for death (odds ratio, 1.4; 95% confidence interval, 1.2-1.5; P < 0.0001).

CONCLUSION

This study provides information on the incidence of and demographic risk factors for admission to ICUs in a defined population. Inclusion of patients that are nonresident in base study populations may lead to gross errors in determination of the occurrence and outcomes of critical illness.

Clinical application of bioartificial liver support systems

OBJECTIVE

To review the present status of bioartificial liver (BAL) devices and their obtained clinical results.

BACKGROUND

Acute liver failure (ALF) is a disease with a high mortality. Standard therapy at present is liver transplantation. Liver transplantation is hampered by the increasing shortage of organ donors, resulting in high incidence of patients with ALF dying on the transplantation waiting list. Among a variety of liver assist therapies, BAL therapy is marked as the most promising solution to bridge ALF patients to liver transplantation or to liver regeneration, because several BAL systems showed significant survival improvement in animal ALF studies. Until today, clinical application of 11 different BAL systems has been reported.

METHODS

A literature review was performed using MEDLINE and additional library searches. Only BAL systems that have been used in a clinical trial were included in this review.

RESULTS

Eleven BAL systems found clinical application. Three systems were studied in a controlled trial, showing no significant survival benefits, in part due to the insufficient number of patients included. The other systems were studied in a phase I trial or during treatment of a single patient and all showed to be safe. Most BAL therapies resulted in improvement of clinical and biochemical parameters.

CONCLUSIONS

Bioartificial liver therapy for bridging patients with ALF to liver transplantation or liver regeneration is promising. Its clinical value awaits further improvement of BAL devices, replacement of hepatocytes of animal origin by human hepatocytes, and assessment in controlled clinical trials.

[Acute liver failure. Current aspects of diagnosis and therapy]

Disturbances of some partial liver functions, such as synthesis, excretion, or biotransformation of xenobiotics, are important for prognosis and ultimate survival in patients presenting with multiple organ dysfunction on the intesive care unit (ICU). The incidence of liver dysfunction is underestimated when traditional "static" measures such as serum-transaminases or bilirubin as opposed to "dynamic" tests, such as clearance tests, are used to diagnose liver dysfunction. Similar to the central role of the failing liver in MODS, extrahepatic complications, such as hepatorenal syndrome and brain edema develop in acute or fulminant hepatic failure and determine the prognosis of the patient. This is reflected in the required presence of hepatic encephalopathy in addition to hyperbilirubinemia and coagulopathy for the diagnosis of acute liver failure. In addition to these clinical signs, dynamic tests, such as indocyanine green clearance, which is available at the bed-side, are useful for the monitoring of perfusion and global liver function. In addition to specific and causal therapeutic interventions, e.g. N-acetylcysteine for paracetamol poisoning or termination of pregnancy for the HELLP-syndrome, new therapeutic measures, e.g. terlipressin/albumin or albumin dialysis are likely to improve the poor prognosis of acute-on-chronic liver failure. Nevertheless, liver transplantation remains the treatment of choice for fulminant hepatic failure when the expected survival is <20%.