Etiology and outcome for 295 patients with acute liver failure in the United States

Little information is available on acute liver failure (ALF) in the United States. We gathered demographic data retrospectively for a 2-year period from July 1994 to June 1996 on all cases of ALF from 13 hospitals (12 liver transplant centers). Data on the patients included age, hepatic coma grade on admission, presumed cause, transplantation, and outcome. Among 295 patients, 74 (25%) survived spontaneously, 121 (41%) underwent transplantation, and 99 (34%) died without undergoing transplantation. Ninety-two of 121 patients (76%) survived 1 year after transplantation. Acetaminophen overdose was the most frequent cause (60 patients; 20%), followed by cryptogenic/non A non B non C (NANBNC; 15%), idiosyncratic drug reactions (12%), hepatitis B (10%), and hepatitis A (7%). Spontaneous survival rates were highest for patients with acetaminophen overdose (57%) and hepatitis A (40%) and lowest for those with Wilson's disease (no survivors of 18 patients). The transplantation rate was highest for Wilson's disease (17 of 18 patients; 94%) and lowest for autoimmune hepatitis (29%) and acetaminophen overdose (12%). Age did not differ between survivors and nonsurvivors, perhaps reflecting a selection bias for patients transferred to liver transplant centers. Coma grade on admission was not a significant determinant of outcome, but showed a trend toward affecting both survival and transplantation rate. These findings on retrospectively studied patients from the United States differ from those previously gathered in the United Kingdom and France, highlighting the need for further study of trends in each country.

[Liver transplantation in acute liver failure]

Acute hepatic failure is characterized by jaundice and hepatic encephalopathy within eight weeks after the onset of disease. Although acute hepatic failure is a rare occurrence, its rapid progression and high mortality (50 to 90%, depending on the etiology of disease) necessitate immediate intervention. In the absence of causal therapy, orthotopic liver transplantation is currently the only definitive and effective means of treating acute hepatic failure in Europe, acute hepatic failure accounts for 11% of all liver transplantations. At the University department of transplantation surgery in Vienna a total of 27 patients with acute hepatic failure underwent 31 liver transplantations in the last 10 years (1.1.1987 to 31.12.1996). Twenty (74%) of the 27 patients survived the acute event and were discharged from hospital in good general condition after a median postoperative stay of 25 days (range 14-81 days). Seven patients (26%) died between the first and 34th postoperative day (median 26 days) in the intensive care unit, although all potential modern options of intensive care and surgery were used. The causes of death were irreversible cerebral edema (n = 3), multiple organ failure due to bacterial sepsis (n = 3) and uncontrollable haemolysis (n = 1). With a 3-year graft survival rate of 70% the 3-year patient survival rate was 74%. A retrospective analysis of our patients revealed that the postoperative graft function and the incidence of re-transplantation were significant prognostic factors (p < 0.05) for survival following orthotopic liver transplantation for acute hepatic failure. In the absence of further prognostically relevant preoperative indices and in consideration of the potentially fulminant progression of disease, we strongly recommend that any patient, in whom acute hepatic failure is suspected, is immediately transferred to a specialized center with experience both in the conservative treatment of acute hepatic failure and emergency liver transplantation.

[Prognostic factors in acute liver failure]

Acute liver failure is defined as acute severe, potentially reversible hepatic failure complicated by cerebral dysfunction. The high mortality rate of between 50% and 90% justifies early transfer to a specialised centre with the possibility of orthotopic liver transplantation to ensure adequate intensive care monitoring and treatment, 57 patients with acute liver failure (34 female, 23 male, aged 6 to 87 years, median 33 years) treated at our intensive care unit during the past 10 years were analysed retrospectively. Various factors and laboratory data were analysed in respect to their prognostic value. Depending on the aetiology, the survival rate in acute liver failure under conservative treatment ranges from 79% (amanita intoxication) to 10% (cryptogenic genesis). The most important predictive parameter is the extent of cerebral dysfunction. The extent of cerebral dysfunction is a determining factor of the survival rate under conservative treatment; it ranges from 94% (patients with hepatic encephalopathy grade I) to 11% (patients with hepatic encephalopathy grade IV). The occurrence of complications such as infections, cerebral oedema, respiratory failure or renal failure is also associated with an unfavourable outcome. Additionally, various laboratory parameters have a predictive ability. The mortality rate of our patients with acute liver failure has decreased from 56% to 32% since early intensive care monitoring and treatment and the possibility of acute orthotopic liver transplantation were established.

Treatment of fulminant hepatic failure with intravenous prostaglandin E1

Fulminant hepatic failure (FHF) is a severe, life-threatening disorder. Previous studies have suggested that intravenous prostaglandin treatment may improve survival in FHF. The present study was performed to further investigate the possible benefit of intravenous prostaglandin E1 (PGE1) for patients with FHF. A total of 18 patients, all excluded as candidates for hepatic transplantation, were studied. Thirteen of 18 participated in a randomized, double-blind, placebo-controlled trial. PGE1 was administered by continuous infusion at a dose of 10 to 40 microg/h as tolerated. After 48 hours of blinded treatment, 3 of 7 patients randomized to placebo were converted to open-label PGE1 for lack of biochemical and/or clinical improvement. Mean values for alanine transaminase, aspartate transaminase, total bilirubin, prothrombin time, factor V percent, factor VII percent, hepatic encephalopathy score, days from onset of symptoms to initiation of treatment, and cause of FHF were similar between treatment groups. Ten of 18 patients (55%) enrolled in this trial survived. However, survival was not different between PGE1-(60%) and placebo (50%) treated patients. The greatest predictor of survival was the number of days from onset of symptoms to hospitalization, which was significantly (P = .002) shorter for survivors (3.3 v 12.4 days), regardless of PGE1 treatment. Six of 8 patients (75%) who began PGE1 therapy and 4 of 5 placebo-treated patients (80%) hospitalized within 10 days of onset of symptoms survived. By contrast, all 5 patients who were hospitalized and subsequently began PGE1 treatment 10 days or longer after the onset of symptoms died. We conclude that early recognition and hospitalization is the most important factor in reduction of mortality from FHF. It is unclear whether PGE1 treatment is beneficial when administered during this period. However, it is apparent that PGE1 was not effective for treatment of FHF if treatment started more than 10 days after onset of this clinical syndrome.

Does hepatocyte transplantation in a chemically induced acute hepatic failure make sense?

PURPOSE

Acute hepatic insufficiency (AHF) is one of the major challenges of intensive care medicine. Liver transplantation is the current solution to unsuccessful medical management. Owing to the lack of organ donors, other methods such as hepatocyte transplantation (HcTX) and bioartificial livers need to be explored. The aim of our experimental study is to evaluate the effect of hepatocyte transplantation on the survival in AHF animals intoxicated with D-Galactosamine (D-Gal).

METHODS

The first step consists of the determination of the dose of D-Gal needed to induce at least 80% mortality between 48 and 72 hours. Two groups of a single strain of male Wistar rats are then compared, one being intoxicated with D-Gal (control group), the other receiving and HcTX in the splenic parenchyma 48 hours after intoxication.

RESULTS

The required dose to achieve AHF is 3 gr/kg body weight (Gr. 0). Survival rates are as follow: Gr. 1: D0: 93%; from D1 to D28: 13%. Gr. 2: D0: 80%; D1 and D2: 33%; D3: 20%; D4: 13%, from D5 to D28: 6%. (D0 = Day of transplantation). Liver enzymes show a peak of deterioration at 24 hours, then return to normal values in both groups. Histological examination of those animals still alive and sacrificed on day 28 demonstrates a restitutio ad integrum of hepatic structure. In Group 2, it is possible to observe remaining living hepatocytes in the splenic parenchyma.

CONCLUSIONS

When HcTX is performed 48 hours after D-Gal intoxication, i.e., when the animals begin to develop AHF symptoms, animal survival only significantly improves between days 0 and 3. Unlike other trials, we cannot demonstrate an improvement in long-term survival. Thus, according to this particular experimental model, HcTX is not an alternative for the treatment of AHF.

Transplantation for acute hepatic failure in children

BACKGROUND/PURPOSE

Acute liver failure in the pediatric population is a rare but highly lethal health problem. Sometimes it is difficult to predict who will benefit from liver transplantation. The authors report on their experience in the past 8 years at a pediatric transplant center.

METHODS

A retrospective chart review was performed on all children referred to the liver transplant (TX) service with the diagnosis of acute hepatocellular dysfunction (AHD) from 1988 to 1996. Presentation, chemistries, and clinical course were evaluated. Statistical analysis was performed using analysis of variance.

RESULTS

Twenty-six children underwent evaluation. Seventeen patients fulfilled the criteria for fulminant hepatic failure (FHF). Eleven patients recovered without TX, 14 received a TX, and one died awaiting TX. Of those that received a TX, four died in the early postoperative period and 10 survived (mean follow-up of 4.2 years). There was a wide range in most laboratory values. Serum bilirubin levels, ammonia levels, and coagulation parameters, however, reached statistical significance in patients requiring transplant. The most consistent discriminators of need for transplantation and outcome were neurological findings and multisystem organ failure. Children who recovered without TX had no seizures and minimal encephalopathy. Of the 15 children who were recommended for TX, six had seizures and all had encephalopathy, 12 having grade III or IV. All five nonsurvivors had respiratory failure early in their clinical course, and four of five nonsurvivors also had renal failure.

CONCLUSIONS

There is significant overlap in the presentation and laboratory findings of children who present with AHD or FHF. Neurological status was an important discriminator of need for transplantation. Patients who presented with multisystem organ failure, including renal failure and respiratory failure, had 100% mortality rate despite liver transplantation.

[Progress of acute liver failure and indications for liver transplantation]

OBJECTIVE

To analyse the course of acute liver failure and the indications for liver transplantation.

PATIENTS AND METHODS

In 16 patients who developed acute liver failure between July 1992 and July 1997 the indications for liver transplantation and total survival time were analysed retrospectively.

RESULTS

Intensive medical care (ventilation, dialysis) was necessary in 60% of the patients to bridge organ failure until liver transplantation. In 14 patients liver transplantation was indicated. Eleven of the patients, with a minimal Quick value of less than 10%, presented with the prognostically poorest London criteria. In two patients the combination of three additional criteria of the London classification led to liver transplantation being indicated. In one patient with Wilson's disease the transplantation was undertaken despite good clotting factor synthesis, because an encephalopathy occurred. In two patients liver transplantation was not undertaken even though indicated, in one because liver functions improved, in the other because necrotizing pancreatitis had occurred. In another patient, who had been poisoned by eating the mushroom Amanita phalloides, the attempted transplantation was cut short, because intestinal necrosis had developed, and the patient died during the operation. Nine of the eleven patients who had a transplantation and three of the four treated conservatively survived.

CONCLUSION

The 60-day survival rate in this series, achieved in a recently established transplantation programme, is high (12 of 16; 75%), being comparable to those in larger transplantation centres.

Liver failure and death after exposure to microcystins at a hemodialysis center in Brazil

BACKGROUND

Hemodialysis is a common but potentially hazardous procedure. From February 17 to 20, 1996, 116 of 130 patients (89 percent) at a dialysis center (dialysis center A) in Caruaru, Brazil, had visual disturbances, nausea, and vomiting associated with hemodialysis. By March 24, 26 of the patients had died of acute liver failure.

METHODS

A case patient was defined as any patient undergoing dialysis at dialysis center A or Caruaru's other dialysis center (dialysis center B) during February 1996 who had acute liver failure. To determine the risk factors for and the source of the outbreak, we conducted a cohort study of the 130 patients at dialysis center A and the 47 patients at dialysis center B, reviewed the centers' water supplies, and collected water, patients' serum, and postmortem liver tissue for microcystin assays.

RESULTS

One hundred one patients (all at dialysis center A) met the case definition, and 50 died. Affected patients who died were older than those who survived (median age, 47 vs. 35 years, P<0.001). Furthermore, all 17 patients undergoing dialysis on the Tuesday-, Thursday-, and Saturday-night schedule became ill, and 13 of them (76 percent) died. Both centers received water from a nearby reservoir. However, the water supplied to dialysis center B was treated, filtered, and chlorinated, whereas the water supplied to dialysis center A was not. Microcystins produced by cyanobacteria were detected in water from the reservoir and from dialysis center A and in serum and liver tissue of case patients.

CONCLUSIONS

Water used for hemodialysis can contain toxic materials, and its quality should therefore be carefully monitored.

Earlier identification of patients at risk from acetaminophen-induced acute liver failure

OBJECTIVE

To determine whether the Acute Physiology and Chronic Health Evaluation (APACHE) II system for the measurement of severity of illness is able to provide an accurate risk of hospital death in patients with acetaminophen-induced acute liver failure or identify those patients needing transfer for possible hepatic transplantation.

DESIGN

Data for admission (first 24 hrs) APACHE II scores and King's criteria for urgent transplantation were collected prospectively to compare the APACHE II system and the King's criteria for the prediction of death or need for transplantation.

SETTING

A nine-bed specialist liver failure unit (LFU).

PATIENTS

One hundred two consecutive patients admitted to the LFU with acetaminophen self-poisoning and a prolonged prothrombin time were studied.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

An APACHE II score of > 15 points was associated with a high mortality (13/20 patients, five of whom survived following hepatic transplantation). There was no relation between APACHE II risk and outcome (mean APACHE II risk of death 0.8%, actual hospital mortality 16%). An APACHE II score of > 15 had a similar power of prediction of death as the King's criteria (sensitivity 82% and 65%, respectively; specificity 98% and 99%, respectively), when considering those patients who were transplanted as "deaths." An APACHE II score of > 15 was able to identify four more patients than the King's criteria on the first day of admission to the LFU.

CONCLUSIONS

The crude admission APACHE II score correlated well with mortality in patients with acetaminophen-induced acute liver failure. However, the calculated APACHE II risk of death, using the original drug overdose coefficient, was poorly calibrated. Since specialist liver scores are unfamiliar in the general intensive care setting, the use of an APACHE II score might earlier identify more patients at risk of needing a liver transplant, and hence, expedite appropriate transfer to a specialist liver unit.

[Orthotopic liver transplantation in clinical materials]

The authors present their own experience in orthotopic liver transplantation as a treatment of acute and chronic liver failure. 18 transplantations were performed in 16 patients. The indications for transplantation: acute liver failure-3 cases, chronic advanced disease of the liver-13 cases, graft failure requiring retransplantation-2 cases. All 3 patients with acute failure died after transplantation. Out of 13 patients after elective transplantations 11 remain alive, (in this number both retransplanted). The longest follow-up period is 2.5 years.

Efficacy and limitation of apheresis therapy in critical care

Apheresis therapy such as plasma exchange and plasma adsorption has become therapeutic tools in critical care. The indications for apheresis therapy in ICU patients include fulminant hepatic failure, thrombotic thrombocytopenic purpura (TTP) and hemolytic uremic syndrome (HUS), autoimmune disease, and sepsis. During the past 11 years, 150 patients with various kinds of critical illnesses were treated with apheresis therapy in our ICU, and the overall survival rate was 50%. Apheresis therapy is especially useful in the treatment of a patient with fulminant hepatic failure because liver transplantation is seldom performed in Japan; therefore, the patient should be treated with artificial liver support. When plasma exchange is performed on the critically ill, continuous hemodiafiltration should be performed simultaneously to overcome the adverse effects of plasma exchange such as hypernatremia, metabolic alkalosis, and abrupt changes in colloid osmotic pressure and to enhance the removal rate of the causative middle molecular weight substances of hepatic failure or hepatic coma.

Clinical experience with a bioartificial liver in the treatment of severe liver failure. A phase I clinical trial

OBJECTIVE

The purpose of this study was to develop a bioartificial liver (BAL) to treat patients with severe liver failure until they can be either transplanted or recover spontaneously.

SUMMARY BACKGROUND DATA

Severe acute liver failure is associated with high mortality. Liver transplantation has emerged as an effective therapy for patients who did not respond to standard management. However, because of the donor organ shortage and urgent need for transplantation, many patients die before they can be transplanted and others do not survive after transplantation, primarily because of intracranial hypertension.

METHODS

Three groups of patients with severe acute liver failure were treated with the BAL. In group 1 (n = 18) were patients with fulminant hepatic failure (FHF), in group 2 (n = 3) were patients with primary nonfunction (PNF) of a transplanted liver, and in group 3 (n = 10) were patients with acute exacerbation of chronic liver disease. Patients in groups 1 and 2 were candidates for transplantation at the time they entered the study, whereas patients in group 3 were not.

RESULTS

In group 1, 16 patients were "bridged" successfully to transplantation, 1 patient was bridged to recovery without a transplant, and 1 patient died because of concomitant severe pancreatitis. In group 2, all patients were bridged successfully to retransplantation. In group 3, two patients were supported to recovery and successful transplants at later dates; the other eight patients, although supported temporarily with the BAL, later died because they were not candidates for transplantation.

CONCLUSIONS

The authors' clinical experience with the BAL has yielded encouraging results. A randomized, controlled, prospective trial (phase II-III) is being initiated to determine the efficacy of the system.

Delayed encephalopathy in fulminant hepatic failure in the pediatric population and the role of liver transplantation

BACKGROUND

Liver transplantation is the therapeutic choice for fulminant hepatic failure in children.

METHODS

All 66 cases of fulminant hepatic failure in the pediatric population seen at UCLA from May, 1985 to November, 1993 were reviewed to determine changes in survival rates since the advent of liver transplantation. We evaluated the clinical course and events leading to the exclusion of surgical management of nonsurvivors, who otherwise would have benefited from a liver transplant. We also compared the latter's clinical course with the nontransplant survivors to determine parameters for screening patients for liver transplantation.

RESULTS

Fifty-one patient (77%) were put on the transplant list initially but eventually, only 38 (58%) patients underwent orthotopic liver transplantation (OLT) and of these 30 (79%) patients survived. Of the remaining 29 (42%) patients who did not undergo liver transplantation, only 10 (36%) patients survived. Nine patients died while waiting for a donor liver secondary to complications of hepatic failure. The majority of nonsurvivors in the OLT and no-OLT groups succumbed because of irreversible neurologic deterioration. In the no-OLT group, comparisons between survivors and non-survivors were made. There were no significant demographic differences. It took a mean of 8 days (+/-8) versus 22 days (+/-15), (p = 0.009), from onset of illness to first hospital admission for survivors and nonsurvivors, respectively. Time to reach stage II encephalopathy was a mean of 5 days (+/-5) for survivors versus 18 days (+/-16), (p = 0.05) for nonsurvivors. Nonsurvivors were transferred to the transplant center at a mean of 12.2 days (+/-12) after being first admitted elsewhere as compared to a mean of 1.9 days (+/-18) for survivors, (p = 0.02). Mean prothrombin time decreased by a mean of 13.4 s/day (+/-16) for survivors as against 2.25 s/day (+/-6) for nonsurvivors, (p = 0.06). Mean peak total bilirubin for nonsurvivors was 460 mumol/L (27 mg/dl) versus 220 mumol/L (13 mg/dl) for survivors, (p = 0.06). Nonsurvivors died at a mean of 30 days (+/-19) from onset and survivors' liver tests started to improve at a mean of 11 days (+/-9) from onset.

CONCLUSIONS

From these studies, we conclude that liver transplantation remains the therapeutic choice for fulminant hepatic failure in children. Early referral and closer follow-up is necessary for timely admission to liver transplant centers to enable screening and proper preparation of these patients for liver transplantation.

Acute liver failure: spontaneous recovery or transplantation?

BACKGROUND

Decision-making in acute liver failure. Acute liver failure is a disease with multiple organ involvement and a high mortality rate. Conservative management alone will only partly influence the outcome. The option of emergency liver transplantation has greatly improved survival rates, but unables spontaneous recovery. A set of prognostic criteria enables selection of patients who will benefit the most from emergency liver transplantation.

METHODS

Retrospective review and survey of the Groningen results.

RESULTS

Of 52 patients (33 adults and 19 children) admitted for acute liver failure 2 were beyond recovery and died, 9 were treated conservatively and recovered and 41 were listed for emergency liver transplantation because of an estimated survival rate < 20%. Of these, 3 died and 1 recovered spontaneously while waiting and 37 were transplanted. Survival rate for 41 patients listed for transplantation was 23 (56%) and was similar for children and adults.

CONCLUSIONS

In patients with acute liver failure, management and decision-making in a specialized liver unit with the possibility of emergency liver transplantation is mandatory.

Acute hepatic failure following transcatheter arterial embolization for the treatment of hepatocellular carcinoma

We conducted a retrospective analysis to evaluate the risk factors associated with the occurrence of acute hepatic failure following transcatheter arterial embolization (TAE) for hepatocellular carcinoma. From 1984 to 1993 we performed a total of 623 embolization procedures in 369 patients with both hepatocellular carcinoma and chronic liver disease. Within 2 weeks after TAE, 13 patients (2.1%) experienced hepatic failure as characterized by a rapid increase in serum bilirubin levels and the development of hepatic encephalopathy of grade 2 or higher. These results indicated that the following are risk factors for acute hepatic failure after TAE: poor hepatic functional reserve; high-dose infusion of chemotherapeutic agents, and a history of multiple embolization procedures.

Liver transplantation in Europe for patients with acute liver failure

Approximately 11% of all liver transplants performed in Europe are for acute liver failure, with one-year patient survival rates ranging between 50% and 75%. This review summarizes the selection, perioperative management, and outcome of patients transplanted for acute liver failure, with particular reference to the experience at the Hôpital Paul Brousse in Paris and at King's College Hospital, London. In both centers, the decision to proceed to liver transplantation is based on criteria that predict a survival of less than 20% with medical management alone. Infectious complications and cerebral edema remain the most common causes of death, and highlight the importance of intensive monitoring and early treatment of perioperative complications. In selected patients, auxiliary partial orthotopic liver transplantation may be a therapeutic option, with the potential for native liver generation and eventual immunosuppression withdrawal in approximately two-thirds of patients.

Classification, etiology, and considerations of outcome in acute liver failure

Clinical descriptions of fulminant hepatic failure as originally reported, along with the subgroups of subfulminant and late onset hepatic failure identified later, are considered in relation to the proposed new classification of hyperacute, acute, and subacute liver failure. This reflects different clinical patterns of illness, etiology, and most importantly, prognosis. In addition to the defining state of encephalopathy and other manifestations directly related to the severe derangement in function and structure of the liver, the constellation of clinical symptoms and signs in acute liver failure (ALF) includes, to varying degrees, those of multiorgan failure. The latter develops because of tissue hypoxia from microcirculatory changes consequent on endotoxemia, and activation of macrophages and release of cytokines as a result of secondary bacteria infection due to an early failure of host defenses to infection in ALF. Paracetamol overdose-the commonest cause of acute liver failure in the United Kingdom-is increasing in frequency in other Western countries, but fulminant viral hepatitis is the most frequent etiology worldwide. Marked geographical variations are seen in the frequency with which the viral types A to E are implicated. Whereas hepatitis C is the major cause of ALF in Japan and the Far East, fulminant hepatitis C is seen rarely in America and European countries where most series show that in about one third of cases of presumed viral ALF, no specific agent can be identified. Over the past 10 years, the survival of those with grade 3 to 4 encephalopathy has shown a steady rise as a result of improvements in medical care, quite apart from the introduction and now widespread availability of transplantation for the treatment of this condition. As shown by a number of groups, a variety of different hematologic, biochemical, and clinical features can be used as predictive indices of the likely outcome and in determining the approach to treatment.

Use of bioartificial and artificial liver support devices

With all the new work and current interest in extracorporeal liver support systems incorporating hepatocytes, the findings with earlier artificial systems need to be reconsidered, particularly as they may constitute a component of some bioartificial devices. Furthermore, new and more effective artificial systems are currently under development. Essential hepatic functions need to be replaced, including excretory (the capability of adsorbents and dialysis) and synthetic and biotransformatory function, but the relative importance of these three functions in terms of promoting recovery of the native liver is as yet unclear. Two bioartificial devices have already been used clinically in the treatment of acute liver failure (ALF): the bioartificial liver (BAL) based on pig hepatocytes attached to microcarriers, and the extracorporeal liver assist device (ELAD) which contains a human liver-derived tumor cell line. As with earlier completely artificial systems, the results so far obtained in man are less impressive than in animal models of ALF. An important question not yet answered relates to quantity of cells and specific function in the new hybrid bioreactor devices required for clinical benefit, as well as the duration of support needed. A better understanding of the effects of these devices on the metabolic function of the damaged liver and the recovery process will be essential in the further development and design of effective systems. Controlled clinical trials on a multicenter basis will be needed for proper evaluation of these new approaches to treatment of ALF. From our own initial experience, the design of these protocols and the selection of biochemical tests will be difficult.

The American experience with transplantation for acute liver failure

Liver transplantation has become the major therapy for acute liver failure (ALF) in the United States. Survival rates range from 46% to 89%. Appropriate patient selection, timely referral, and management of common complications have improved survival. Donor organ shortage may prompt further use of extracorporeal support systems and auxillary transplantation in the future. This article reviews the American experience of liver transplantation in patients with ALF.

Clinical experience with a porcine hepatocyte-based liver support system

The only clinically proven effective treatment of fulminant hepatic failure (FHF) is orthotopic liver transplant (OLT). However, many patients die before an organ becomes available. Thus, there is a need for development of an extracorporeal liver support system to "bridge" these patients either to OLT or spontaneous recovery. We developed a bioartificial liver (BAL) based on plasma perfusion through a circuit of a hollow-fiber cartridge seeded with matrix-anchored porcine hepatocytes to treat patients with severe acute liver failure. Two groups of patients were studied. Group 1 (n = 12): patients with FHF. All patients were successfully "bridged" to OLT. "Bridge" time to OLT was 21-96 hr (mean: 39.3 hr). All patients were discharged neurologically intact. Reversal of decerebration was noted in all 11 deep stage 4 coma patients. There was reduction in intracranial pressure (ICP mmHg, 18.2 +/- 2.2 to 8.5 +/- 1.2; p < 0.004) and increase in cerebral perfusion pressure (CPP mmHg, 71.1 +/- 4.0 to 84.7 +/- 2.6; p < 0.006). Laboratory values pre- and post-BAL treatment: glucose (mg/dl) 122 +/- 11 to 183 +/- 21, p < 0.002; ammonia (mumol/l) 155.6 +/- 13.2 to 121.6 +/- 9.5, p < 0.02; total bilirubin (mg/dl) 21.6 +/- 2.8 to 18.2 +/- 2.2, p < 0.001; PT (sec) 23.2 +/- 1.7 to 21.9 +/- 1.0, p < 0.3. Group II (n = 8): patients with chronic liver failure experiencing acute exacerbation. Two patients survived and later underwent OLT. Six patients (not OLT candidates) died 1-14 days after last BAL treatment. Laboratory values pre- and post-treatment: ammonia (mumol/l) 201 +/- 47 to 143 +/- 25, p < 0.06; total bilirubin (mg/dl) 22.8 +/- 5.2 to 19.5 +/- 4.4, p < 0.01; PT (sec) 22.5 +/- 2.0 to 21.8 +/- 1.1, p < 0.6.

CONCLUSION

our clinical experience with the BAL suggests that it may serve as "bridge" to OLT in patients with FHF primarily by reversing intracranial hypertension, but it is not a substitute for OLT in patients with end-stage liver disease who are non-transplant candidates.

Xenogeneic (pig to rat) fetal liver fragment transplantation using macrocapsules for immunoisolation

Acute liver failure caused by viral infection, surgical resection of a large part of the liver or by drug use has a high mortality. For its treatment, hepatocyte or liver tissue transplantation is useful. We report here the beneficial effects of xenogeneic fetal liver fragment (FLF) transplantation with an immunoisolation macrocapsule. The macrocapsules were made of a microporous polypropylene membrane. Pig FLFs (1 mL) was inserted into each capsule to serve as a graft in LEW rats. Acute liver failure was induced by 90% liver resection on day 0. Group 1: transplantation of encapsulated FLF into the omentum 2 days before liver resection (n = 17). Group 2: FLF transplantation into the omentum on day -2 (n = 11). Group 3: liver resection (control) (n = 19). The survival rate, the histology of the grafts and the biochemical parameters [blood sugar (BS), GPT, and GOT] were evaluated. The survival rates of groups 1, 2, and 3 on day 7 were 70.6, 0, and 11.1%, respectively. There were significant differences in BS, GPT, and GOT levels between groups 1 and 3 on day 1 (p < 0.05). On day 28, the histological analyses of the grafts of encapsulated FLFs revealed that the hepatocytes appeared viable, but that the haematopoietic cells had degenerated. Xenogeneic FLFs with macrocapsules survived more than 1 mo, and supported the host's liver function.