Does auxiliary heterotopic liver transplantation reverse hypersplenism and portal hypertension?

Long term changes in thrombocytopenia and leucopenia after HCV eradication with direct-acting antivirals

BACKGROUND

Thrombocytopenia due to hypersplenism is a major complication of hepatitis C virus (HCV)-associated cirrhosis. HCV eradication improves these complications in some patients, but the long-term effects of HCV eradication on these complications remain unclear, especially in patients treated with direct acting antivirals (DAAs). The aim was to evaluate long term changes in thrombocytopenia and leucopenia after HCV eradication with DAAs.

METHODS

The present multicenter study retrospectively evaluated changes over 5 years in thrombocytopenia and leukocytopenia, as well as changes in liver fibrosis markers and spleen size, in 115 patients with HCV-cirrhosis treated with DAAs.

RESULTS

Thrombocytopenia and leukocytopenia were improved 4 weeks after DAA administration, with thrombocytopenia show further gradual improvement over the next year. Fib-4 index was markedly reduced 1 year after DAA, followed by subsequent gradual reduction over the next 4 years. Spleen size showed gradual annual reductions, with patients experiencing spleen size reduction characterized at baseline by bilirubinemia.

CONCLUSIONS

Rapid DAA-associated HCV eradication might lead to rapid disappearance of liver inflammation and bone marrow suppression due to HCV infection. HCV eradication may gradually improve portal hypertension, reducing spleen size.

Comprehensive Analysis of Long-term Splenic Volume Changes in Pediatric Liver Transplant Patients: Does It Correlate With Adverse Graft Outcomes?

OBJECTIVES

Splenomegaly and hypersplenism caused by liver failure increase the mortality and morbidity of patients even after liver transplantation if they do not regress. We evaluated the relation of splenic volume change and transplanted liver function.

MATERIAL AND METHODS

A total of 59 of 207 pediatric patients who had liver transplantation between 2013 and 2018 in our institute were evaluated. The relation of spleen volume changes (splenic volume to standard splenic volume ratio [SV/SSV]) were measured at 0, 1, 6, 12, 24, and 36 months of follow-up by constructing electronic three-dimensional structure of the spleen at dynamic computed tomography (CT), and the course of liver functions were evaluated.

RESULTS

The SV/SSV ratio decreases in the first postoperative 6 months. After 6 months, SV increases and SV/SSV increases gradually. In a normal functioning graft, SV/SSV significantly decreased in all time points (P < .001). In patients with adverse events, SV/SSV started to increase after 6 months. In patients with fulminant hepatic failure, SV/SSV started to increase after postoperative 6 months. Adverse events in patients with fulminant hepatic failure were more than the patients with chronic liver disease (58% vs 28%). There was an inverse correlation between SV/SSV and thrombocyte levels (P < .001).

CONCLUSIONS

SV/SSV seems to be correlated to the adverse events (ie, rejection). Together with thrombocyte levels, it can be used as a noninvasive test for follow-up of transplant patients in terms of adverse events in graft function.

Factors Affecting Persistent Splenomegaly After Adult-to-Adult Living Donor Liver Transplantation Using a Left Lobe

BACKGROUND

The aim of the present study was to evaluate spleen volume (SV) and the factors influencing it after adult-to-adult living donor liver transplantation (A2LDLT) using a left lobe.

METHODS

Pretransplant computed tomography (CT) and post-transplant CT 2 years after A2LDLT were examined by volumetric analysis in 24 patients. We divided the recipients into the following 2 groups according to the post-transplant SV: >500 mL (Group A) and ≤500 mL (Group B). The factors affecting the change in post-transplant SV were compared between the 2 groups.

RESULTS

The mean pretransplant SV decreased significantly after A2LDLT. Platelet counts after living donor liver transplantation increased significantly relative to the pretransplant values. Post-transplant SV was >500 mL in 9 patients (Group A) and ≤500 mL in 15 (Group B). Pretransplant SV, platelet count, anhepatic time, operative time, intraoperative blood loss, post-transplant portal vein pressure >20 mm Hg, and post-transplant portal vein flow >250 mL/min/100 g graft weight showed significant differences between the 2 groups. Actual graft volume (GV) and GV/standard liver volume ratio showed no intergroup differences. Multivariate analysis showed that the only significant factor related to a post-transplant SV of >500 mL was the pretransplant SV. Post-transplant platelet counts were significantly increased from the pretransplant values in both Group A and Group B.

CONCLUSIONS

Pretransplant SV is the only significant factor predicting a SV of >500 mL after A2LDLT. However, even in patients with a SV of >500 mL, the platelet count increased significantly from the pretransplant value.

Thrombocytopenia in chronic liver disease

Thrombocytopenia is a common haematological disorder in patients with chronic liver disease. It is multifactorial and severity of liver disease is the most influential factor. As a result of the increased risk of bleeding, thrombocytopenia may impact upon medical procedures, such as surgery or liver biopsy. The pathophysiology of thrombocytopenia in chronic liver disease has long been associated with the hypothesis of hypersplenism, where portal hypertension causes pooling and sequestration of all corpuscular elements of the blood, predominantly thrombocytes, in the enlarged and congested spleen. Other mechanisms of importance include bone marrow suppression by toxic substances, such as alcohol or viral infection, and immunological removal of platelets from the circulation. However, insufficient platelet recovery after relief of portal hypertension by shunt procedures or minor and transient recovery after splenic artery embolization have caused many to question the importance and relative contribution of this mechanism to thrombocytopenia. The discovery of the cytokine thrombopoietin has led to the elucidation of a central mechanism. Thrombopoietin is predominantly produced by the liver and is reduced when liver cell mass is severely damaged. This leads to reduced thrombopoiesis in the bone marrow and consequently to thrombocytopenia in the peripheral blood of patients with advanced-stage liver disease. Restoration of adequate thrombopoietin production post-liver transplantation leads to prompt restoration of platelet production. A number of new treatments that substitute thrombopoietin activity are available or in development.

Long-term dynamics of hematological data and spleen volume in cirrhotic patients after liver transplantation-various dynamics depending on etiology

Background

Hypersplenism is a common complication in cirrhotic patients, and liver transplantation would be one of the effective treatments. However, detailed dynamics, especially over a long term, are not fully understood. We investigated the long-term dynamics of hematological data and spleen volumes, as well as their correlation in cirrhotic patients who underwent liver transplantation.

Patients and methods

We studied 53 cirrhotic patients who underwent liver transplantation at our institute and followed for more than 1 year. Hematological data were collected from medical records, while spleen volumes were determined by CT volumetry at 0, 1, 3, 6, 12, 24, 36, 48, 60 postoperative months (POM).

Results

(1) Platelet (Plt) and hemoglobin (Hb) levels were gradually increased up to 18 and 10 POM, respectively, in contrast with white blood cells (WBC), which remained mostly unchanged from pretransplantation levels. (2) Spleen volume was sharply decreased in the first POM, then showed a slower but steady decline up to 48 POM. (3) Spleen volume was significantly correlated with hematological data, though the levels were generally weak (Plt: r = 0.433, p < 0.001; Hb: r = 0.233, p < 0.001; WBC: r = 0.217, p = 0.001). (4) Spleen volume was strongly correlated with all hematological parameters in HBV patients (Plt: r = 0.617, p < 0.0001; Hb: r = 0.401, p < 0.001; WBC: r = 0.387, p < 0.001), in contrast with that in other etiologies, which had generally weak correlations though some were statistically significant.

Conclusions

We investigated the long-term dynamics of hematological data and spleen volume in cirrhotic patients after liver transplantation. Unique dynamics and correlations between them were found among the different etiologies investigated.

Change in platelet count in patients with hypersplenism subjected to liver transplantation

CONTEXT: Most patients subjected to liver transplantation presents hypersplenism, which is reversed after the operation. However, some patients remain with moderate to intense hypersplenism. OBJECTIVES: To study the effect of liver transplantation on platelet count in patients with hypersplenism. METHOD: Of a total of 233 patients who underwent liver transplantation, 162 were excluded from the present study because of occurrence of steroid-resistant rejection, absence of hypersplenism before the transplantation, absence of follow-up for at least 2 years or incomplete exams data. The electronic study protocols of the remaining 71 patients were reviewed to determine the demographics, etiology of cirrhosis, and results of pathologic examination of the explanted liver. Serial platelet count was obtained from the study protocol on the day before liver transplantation and 1, 2, 4, and 6 months and 1 year after liver transplantation. Statistical analysis was performed using the Student's t-test, chi-square test, and Spearman's correlation test. RESULTS: Posttransplant platelet count at all time intervals was significantly higher than the pretransplant value (P<0.001 for all time intervals). Thrombocytopenia was reversed (platelet count >100,000/mm³) in 58 patients (81.7%) 1 month after liver transplantation. Twelve patients (16.9%) remained with thrombocytopenia 1 year after liver transplantation. Three patients (4.2%) had recurrence of thrombocytopenia within 1 year after liver transplantation. There was no correlation between pretransplant platelet count and the Child-Pugh class or the MELD score. CONCLUSION: Liver transplantation reverses hypersplenism in most patients.

Liver fibrosis is associated with decreased peripheral platelet count in patients with chronic hepatitis B and C

Thrombocytopenia is a common complication of chronic liver diseases, but its pathogenesis is not clear. Although generally attributed to hypersplenism, other factors should also be considered. We investigated the relationship between the peripheral platelet count and the degree of fibrosis in patients with chronic viral hepatitis. In an effort to avoid the effects of hypersplenism, we excluded patients with splenomegaly and/or bi- or pan-cytopenia. Seven hundred eighty-four patients (265 chronic viral hepatitis C and 519 chronic viral hepatitis B) were included in the study. Univariate analysis showed that the peripheral platelet count had a negative correlation with fibrosis score, necroinflammatory activity, and age in both groups. In multivariate analysis, the peripheral platelet count had a similar correlation with the fibrosis score and age, but not with necroinflammatory activity, in both groups. The peripheral platelet count decreased more significantly in females with chronic hepatitis C but not in the chronic hepatitis B group. In conclusion, a decrease in peripheral platelet count may be a sign of an increase in the degree of fibrosis during the course of chronic viral hepatitis B and C and factors other than hypersplenism may play a role in this decrease in the peripheral platelet count.

Effect of liver transplantation on tuftsin activity and phagocytic activity of neutrophil granulocytes in patients with liver cirrhosis

BACKGROUND

Tuftsin activity (TA) is reduced in cirrhosis. This contributes to the defective phagocytic activity (PA) of neutrophil granulocytes and is related to the impairment of splenic function. Orthotopic liver transplantation (OLT) cures cirrhosis and might restore TA. This study was aimed at determining if OLT restores TA and PA.

METHODS

We measured in 9 cirrhotic patients, before and after successful OLT, TA by a bioassay and PA by chemiluminescence in which neutrophils of the patient were tested with both autologous (PA1) and pooled sera from healthy subjects (PA2). Splenic function was assayed by the pitted red cell count.

RESULTS

Before OLT, TA was reduced in 7 patients, and PA1 in all the patients. Pitted cell count was elevated in all the patients. After OLT (median 39 months; range 21-49), TA improved in all cases [median: from 8% (5-16%) to 20% (9-22%), p < 0.008], normalizing in 5 out of the 7 patients with low values. PA1 improved in all the patients [from 102 cpm (65-128 cpm) to 235 cpm (78-280 cpm), p < 0.008], normalizing in 5. Pitted red count decreased in 7 patients and normalized in 3 [from 3.3% (2.1-6.0%) to 2.4% (1.4-2.8%), p < 0.021]. Platelet count [from 55 x 10(3) (30-100) to 185 x 10(3) (93-286), p < 0.008] and leucocyte count [from 3.60 x 10(3) (1.81-5.23) to 5.53 x 10(3) (3.31-6.71), p < 0.008] also improved.

CONCLUSIONS

OLT improves TA and PA of cirrhotic patients. This effect is associated with an improvement of both functional hyposplenism and haematological hypersplenism. The restoration of natural defences against infections may mitigate the adverse effect of immunosuppressive treatment.

Effect of pediatric living-donor liver transplantation on splenomegaly

BACKGROUND

The effect of pediatric partial liver transplantation on hypersplenism has not yet been clarified.

METHODS

Fifty-five consecutive pediatric patients who underwent living-donor liver transplantation were analyzed. The volume of the spleen was measured by computed tomography, and the spleen volume-to-standard spleen volume ratio (R) was calculated in each patient. The platelet counts were examined preoperatively and at 1, 6, 12, 18, 24, 36, and 48 months after the operation. The rate of the decline in this ratio during 1 year was calculated, and correlations with clinical factors were examined.

RESULTS

The ratio decreased gradually after the operation in all of the patients except for three with an eventful postoperative course. The rate of the reduction in R within 1 year after the operation was well correlated with preoperative R (R(O); P<0.0001), which led to an equation for R at n months after the operation: R(n) =(0.31-0.21R(O) )Ln(3.3n+1)+R(O). The platelet counts increased rapidly in the patients with the uneventful postoperative course.

CONCLUSIONS

The normalization of spleen size can be expected with an uneventful living-donor liver transplantation. The spleen volume decreased more rapidly in patients with a larger spleen.

Hypersplenism

Cytopenias in liver disease are a common finding. In the past they have mostly been attributed to pooling and/or destruction of blood cells in the enlarged spleen, leading to the term 'hypersplenism'. With recent advances in the understanding of the physiology of blood formation, in particular with the discovery of several haematopoietic growth factors, new insight into the pathophysiology of blood cell derangements in liver disease has been obtained. Recombinant haematopoietic growth factors present new opportunities for support of the haematopoietic system, which is required because of toxic antiviral therapies or surgical interventions in these patients.

Splenomegaly, hypersplenism and coagulation abnormalities in liver disease

Splenomegaly is a frequent finding in patients with liver disease. It is usually asymptomatic but may cause hypersplenism. Thrombocytopenia is the most frequent manifestation of hypersplenism and may contribute to portal hypertension related bleeding. A number of therapies are available for treating thrombocytopenia due to hypersplenism including splenectomy, partial splenectomy, partial splenic embolization, TIPS etc. None is entirely satisfactory. Hypersplenism usually improves following liver transplantation. Therapy with cytokines such as thrombopoietin may offer hope for the future. Patients with liver disease also have abnormalities in coagulation. This is not surprising as all coagulation proteins (except for von willebrand factor vWF) and most inhibitors of coagulation are synthesized in the liver. Genetic or acquired abnormalities of coagulation may predispose to thrombosis of the hepatic or portal veins with significant clinical sequelae. An understanding of the mechanisms involved in coagulation and thrombosis is valuable in choosing from the increasing treatment options available. These include clotting factors, haemeostatic drugs and newer therapies such as recombinant factor VIIa. Splenic artery aneurysms are the most common visceral artery aneurysms in man. Rupture is frequently catastrophic. These aneurysms are being increasingly recognized in liver transplant patients and require treatment before or during transplant surgery.

Functional, life-threatening disorders and splenectomy following liver transplantation

Splenectomy (SPL) in cirrhotic patients undergoing liver transplantation (LTx) may resolve specific problems related to the procedure itself, in case of functional and life-threatening clinical situations often occurring as a result of liver cirrhosis and portal hypertension.

METHOD

A single-center experience of ten splenectomies in a series of 180 consecutive adult liver transplant patients over a period of 6 yr is reported. The mean patient age was 46.8 +/- 9.5 yr (range 25 57 yr). Indications for SPL were post-operative massive ascitic fluid loss (n = 3), severe thrombocytopenia (n = 3), acute intra-abdominal hemorrhage (n = 2), infarction of the spleen (n = 1), and multiple splenic artery aneurysms (n = 1).

RESULTS

Extreme ascites production due to functional graft congestion disappeared post-SPL, with an improvement of the hepatic and renal functions. SPL was also effective in cases of thrombocytopenia persistence post-LTx, leading to an increase in the platelet count after about 1 wk. Bleeding episodes related to left-sided portal hypertension or trauma were also resolved. The rejection rate during hospitalization was 0%, and no other episodes were recorded in the course of the long-term follow-up. However, sepsis with a fatal outcome occurred in 4 patients, i.e. between 2 and 3 wk post-SPL in three cases and 1 yr after the procedure as a result of pneumococcal infection in the last case. Fatal traumatic cranial injury occurred 3 yr post-LTx in another case. Five patients (50%) are still alive and asymptomatic after a median follow-up period of 36 months.

CONCLUSION

The lowering of the portal flow appears to resolve unexplained post-operative ascitic fluid loss as a result of functional graft congestion following LTx. However, because of the enhanced risk of SPL-related sepsis, a partial splenic embolization (PSE) or a spleno-renal shunt could be used as an alternative procedure because it allows us to preserve the immunological function of the spleen. SPL is indicated in case of post-transplant bleeding due to left-sided portal hypertension and trauma, spleen infarction, and to enable prevention of hemorrhage in liver transplant patients with multiple splenic artery aneurysms. Severe and persistent thrombocytopenia could be treated with PSE. Because the occurrence of fatal sepsis post-SPL is a major complication in LTx, functional disorders, such as ascites and thrombocytopenia, should be treated with a more conservative approach.

Direct evidence for an increase in thrombopoiesis after liver transplantation

BACKGROUND

In advanced liver cirrhosis, thrombocytopenia results from 'hypersplenism' due to increased platelet sequestration and platelet 'pooling' in the enlarged spleen and/or from reduced platelet production in the bone marrow. We sought to differentiate between these two mechanisms by studying thrombopoiesis before and after orthotopic liver transplantation by the determination of reticulated platelets, direct indicators for the thrombopoietic activity in the bone marrow.

METHODS

Reticulated platelets, peripheral platelet counts, mean platelet volumes and platelet-reactive antibodies were determined in 15 patients suffering from advanced liver cirrhosis before and during an observation period of 14 days after orthotopic liver transplantation (OLT). Thrombopoietin levels of ten patients were determined before transplantation and consecutively for 14 days after surgery.

RESULTS

All patients except one were thrombocytopenic before transplantation (median count 94 x 10(9) L-1, range 69-114 x 10(9) L-1). Although levels of reticulated platelets rose 2 days after surgery from baseline values of 1.0% (range 0.2-1.6%) to peak values of 4.6% (range 1.7-17.9%, P < 0.05) on day 6, platelet counts declined during the first 5 days after transplantation. When peripheral platelet counts increased to the normal range (median day 11, range day 8-33), reticulated platelets were again at pretransplant levels. Thrombopoietin levels before OLT were within the normal range (< 85 pg mL-1). On day 5 post surgery, a maximum increase of 5.8-fold (range 2.2- to 28-fold) over baseline values was observed. Mean platelet volume did not show any significant deviation from the baseline values and platelet antibodies could not be detected during the observation period.

CONCLUSION

Our findings provide direct evidence for an increase in de novo platelet production after orthotopic liver transplantation. As the elevation of reticulated platelets precedes platelet recovery, it could serve as an early indicator to predict thrombopoiesis as a result of reconstituted liver function.

Splenic impedance indices: a useful method to monitor patients after liver transplantation?

Splenic Doppler impedance indices are influenced, in portal hypertensive patients, by the resistance of the portal system. The aim of the study was to verify the usefulness of these indices in evaluating the presence of a pathological increase in portal resistance in patients with complications after liver transplantation. Splenic impedance indices have been evaluated in 46 patients before orthotopic liver transplantation (OLT), and 2 days, 1, 4, 8, and 12 to 18 months after transplantation. The results showed that spleen size slowly decreased after liver transplantation. From a baseline longitudinal diameter value of 18.0+/-3.6 cm (M+/-SD), the decrease was by 0%+/-3%, 8%+/-8%, 13%+/-9%, 15%+/-11%, and 14%+/-11% at 2 days and 1, 4, 8, and 12 to 18 months after liver transplantation. Splenic impedance indices-resistance index = (peak systolic - end diastolic) / peak systolic velocity; pulsatility index = (peak systolic - end diastolic) / mean velocity-which were increased before liver transplantation, showed a rapid decrease to normal values: resistance index: from 0.62+/-0.08 to 0.55+/-0.08 after 2 days, and to 0.49+/-0.09, 0.51+/-0.10, 0.54+/-0.10, 0.55+/-0.11 after 1, 4, 8, 12-18 months; pulsatility index: from 0.96+/-0.21 to 0.82+/-0.17 after 2 days, and to 0.69+/-0.19,0.72+/-0.21, 0.81+/-0.26, 0.84+/-0.26 after 1, 4, 8, and 12 to 18 months. Patients who had a good outcome, without any major complications, showed a clear and steady decrease in splenic impedance indices. On the contrary, patients who had complications affecting portal resistance (e.g., acute rejection, relapse of chronic hepatitis C virus-related hepatitis or cirrhosis, stenosis of portal anasthomosis, portal thrombosis), showed a lack of decrease, or, after an initial decrease, a subsequent re-increase in splenic impedance indices to pathological values. Splenic impedance indices measured in patients with complications were higher than those of patients without complications (P < .0004). Specificity and sensitivity of splenic impedance indices in the evaluation of the presence of complications increasing portal resistance were good. In conclusion, after OLT, splenic impedance indices could be useful aspecific parameters for identifying patients with complications that are able to affect or increase portal resistance.

Regulation of hepatic thrombopoietin production by portal hemodynamics in liver cirrhosis

OBJECTIVE

This study was designed to clarify how thrombopoietin (TPO) functions in and, to some extent, causes thrombocytopenia complicating liver cirrhosis and portal hypertension.

METHODS

Our study population consisted of 19 cirrhotic and six noncirrhotic patients who underwent percutaneous transhepatic portography (PTP) and hepatic venography.

RESULTS

The platelet counts of the cirrhotic patients were significantly lower than those of the noncirrhotic patients (8.7 +/- 4.1 vs 17.4 +/- 7 x 10(4)/microl; p < 0.01). The flow direction in the splenic vein was confirmed by PTP. Ten hepatofugal and nine hepatopetal flow directions in the splenic vein were noted among the cirrhotics. The hepatofugal group showed lower portal venous pressure (20 +/- 10 vs 32 +/- 4 cm H2O; p < 0.01) than the hepatopetal group and had a higher incidence of hepatic encephalopathy (six of 10 vs zero of nine; p < 0.01). The hepatic vein-portal difference in TPO did not differ substantially between the cirrhotics and noncirrhotics (0.12 +/- 0.04 vs 0.24 +/- 0.07 fmol/ml). Comparisons of this value among the three groups showed the TPO difference to be lowest in the hepatofugal group (hepatofugal: 0.04 +/- 0.03, hepatopetal: 0.21 +/- 0.07, noncirrhotic: 0.24 +/- 0.07; p < 0.05).

CONCLUSIONS

Our findings suggest that TPO production in the cirrhotic liver is regulated by the portal blood supply to the liver. Thus, portal hemodynamics may play a critical role in the development of thrombocytopenia.

Is inadequate thrombopoietin production a major cause of thrombocytopenia in cirrhosis of the liver?

BACKGROUND/AIMS

Thrombocytopenia secondary to cirrhosis of the liver and portal hypertension is a well-known complication of advanced stage liver disease, but theories about the underlying pathogenetic mechanisms, mostly centering on splenic sequestration and destruction of platelets, have failed to solve the problem so far.

METHODS

Peripheral platelet count and thrombopoietin levels in human plasma were measured in 28 patients with cirrhosis of the liver. Seven of those patients underwent orthotopic liver transplantation and five patients portal decompression by transjugular intrahepatic portosystemic shunt. Thrombopoietin plasma levels were followed for 14 days after the interventions.

RESULTS

No measurable thrombopoietin was detectable in the plasma of 28 thrombocytopenic patients with cirrhosis of the liver, in contrast to thrombocytopenic patients without liver disease. Seven of these patients with cirrhosis underwent orthotopic liver transplantation, resulting in a rise of thrombopoietin levels within 2 days after transplantation. The rise in platelet number followed with a mean lag of 6 days, and shortly thereafter, thrombopoietin levels returned to levels below the limit of detection. Five patients with thrombocytopenia, who underwent only decompression of portal hypertension, showed no rise in either thrombopoietin levels or platelet count.

CONCLUSIONS

Thrombocytopenia associated with liver disease may at least in part be attributable to inadequate thrombopoietin production in the failing liver.

New aspects of heterotopic liver transplantation

In this report the history and clinical results of heterotopic liver transplantation (HLT) are reviewed and some special aspects of current research on HLT are high-lighted. The first laboratory experiments on liver transplantation were performed with auxiliary heterotopic grafts. The initial clinical results of HLT, however, were disappointing and orthotopic liver transplantation (OLT) evolved to be the procedure of choice. Of all the patients who received a heterotopic graft before 1980, only two survived. Since 1980, 50 HLTs are known to have been performed on 48 patients. Results of HLTs after 1986 are clearly better than earlier ones, and survival rates come within the range of those reported for OLT. Intraoperative fibrinolysis is found in the anhepatic phase of OLT, something which is absent in HLT. Tissue-type plasminogen activator (t-PA) is said to be responsible for this phenomenon, as well as for the postreperfusion hyperfibrinolysis. Parallel to the hemostatic changes, the intraoperative hemodynamic stability may be impaired by deleterious substances that arise during liver transplantation. Furthermore, the interaction between the two livers, the effect of HLT on portal pressure and hypersplenism, and the possible role of HLT in inborn errors of hepatic metabolism are described. Special attention is given to the treatment of acute hepatic failure. OLT, in an early phase of the disease, negates the possibility of spontaneous recovery, while delay of the decision to transplant may lead to further deterioration of the patient's clinical condition. As the procedure of HLT is reversible, the decision to transplant can be made more quickly. The clinical experience with HLT for acute liver failure is reported in detail.