Usefulness of artificial liver support for pretransplant patients with fulminant hepatic failure

Current state of knowledge of hepatic encephalopathy (part IV): Management of Hepatic Encephalopathy by liver support systems

Hepatic Encephalopathy is a devastating complication of End-Stage Liver Disease. In its severe grades it requires extra intervention beyond the standard medical approaches. In this article were view the role of liver support systems in managing hepatic encephalopthy.

Inhibition of 5-lipoxygenase pathway attenuates acute liver failure by inhibiting macrophage activation

This study aimed to investigate the role of 5-lipoxygenase (5-LO) in acute liver failure (ALF) and changes in macrophage activation by blocking it. ALF was induced in rats by administration of D-galactosamine (D-GalN)/lipopolysaccharide (LPS). Rats were injected intraperitoneally with AA-861 (a specific 5-LO inhibitor), 24 hr before D-GalN/LPS administration. After D-GalN/LPS injection, the liver tissue was collected for assessment of histology, macrophage microstructure, macrophage counts, 5-LO mRNA formation, protein expression, and concentration of leukotrienes. Serum was collected for detecting alanine aminotransferase (ALT), aspartate transaminase (AST), total bilirubin (Tbil), and tumor necrosis factor- (TNF-) α . Twenty-four hours after injection, compared with controls, ALF rats were characterized by widespread hepatocyte necrosis and elevated ALT, AST, and Tbil, and 5-LO protein expression reached a peak. Liver leukotriene B4 was also significantly elevated. However, 5-LO mRNA reached a peak 8 hr after D-GalN/LPS injection. Simultaneously, the microstructure of macrophages was changed most significantly and macrophages counts were increased significantly. Moreover, serum TNF- α was also elevated. By contrast, AA-861 pretreatment significantly decreased liver necrosis as well as all of the parameters compared with the rats without pretreatment. Macrophages, via the 5-LO pathway, play a critical role in ALF, and 5-LO inhibitor significantly alleviates ALF, possibly related to macrophage inhibition.

Acute liver failure and liver transplantation

Acute liver failure (ALF) is defined by the presence of coagulopathy (International Normalized Ratio ≥ 1.5) and hepatic encephalopathy due to severe liver damage in patients without pre-existing liver disease. Although the mortality due to ALF without liver transplantation is over 80%, the survival rates of patients have considerably improved with the advent of liver transplantation, up to 60% to 90% in the last two decades. Recent large studies in Western countries reported 1, 5, and 10-year patient survival rates after liver transplantation for ALF of approximately 80%, 70%, and 65%, respectively. Living donor liver transplantation (LDLT), which has mainly evolved in Asian countries where organ availability from deceased donors is extremely scarce, has also improved the survival rate of ALF patients in these regions. According to recent reports, the overall survival rate of adult ALF patients who underwent LDLT ranges from 60% to 90%. Although there is still controversy regarding the graft type, optimal graft volume, and ethical issues, LDLT has become an established treatment option for ALF in areas where the use of deceased donor organs is severely restricted.

Efficacy of liver assisting in patients with hepatic encephalopathy with special focus on plasma exchange

Severe liver injury result in development of hepatic encephalopathy (HE) and often also in brain edema that is a potentially fatal complication. HE and brain edema are correlated to the level and persistence of hyperammonemia and the presence of systemic inflammation. Treatment of HE and brain edema is based on restoring and keeping normal physiological variables including tonicity, blood gasses, lactate, temperature and vascular resistance by a wide variety of interventions. In addition liver support devices improve the stage of HE, cerebral metabolic rate for oxygen and glucose, and are used either as a bridge to liver transplantation or liver recovery in patients with fulminant hepatic failure and in patients with acute-on-chronic liver failure. This short review will mainly focus on the management and efficacy of doing plasma exchange on HE in patients with acute HE.

Algorithm to determine the outcome of patients with acute liver failure: a data-mining analysis using decision trees

BACKGROUND

We established algorithms to predict the prognosis of acute liver failure (ALF) patients through a data-mining analysis, in order to improve the indication criteria for liver transplantation.

METHODS

The subjects were 1,022 ALF patients seen between 1998 and 2007 and enrolled in a nationwide survey. Patients older than 65 years, and those who had undergone liver transplantation and received blood products before the onset of hepatic encephalopathy were excluded. Two data sets were used: patients seen between 1998 and 2003 (n=698), whose data were used for the formation of the algorithm, and those seen between 2004 and 2007 (n=324), whose data were used for the validation of the algorithm. Data on a total of 73 items, at the onset of encephalopathy and 5 days later, were collected from 371 of the 698 patients seen between 1998 and 2003, and their outcome was analyzed to establish decision trees. The obtained algorithm was validated using the data of 160 of the 324 patients seen between 2004 and 2007.

RESULTS

The outcome of the patients at the onset of encephalopathy was predicted through 5 items, and the patients were classified into 6 categories with mortality rates between 23% and89%. When the prognosis of the patients in the categories with mortality rates greater than 50% was predicted as "death", the accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the algorithm were 79, 78, 81, 83, and 75%, respectively. Similar high values were obtained when the algorithm was employed in the patients for validation. The outcome of the patients 5 days after the onset of encephalopathy was predicted through 7 items, and a similar high accuracy was found for both sets of patients.

CONCLUSIONS

Novel algorithms for predicting the outcome of ALF patients may be useful to determine the indication for liver transplantation.

Emergency versus elective living-donor liver transplantation: a comparison of a single center analysis

Purpose

We studied the risk factors for postoperative mortality between patients who underwent emergency or elective living-donor liver transplantation (LDLT).

Methods

Forty-seven patients underwent LDLT in our institute, 16 for emergencies and 31 as elective procedures. The emergency LDLT status was applied to cases in which the time period between referral to our institution and transplantation did not exceed 10 days, and in which liver failure was accompanied by the presence of any degree of hepatic encephalopathy.

Results

With regard to preoperative factors, age (P = 0.03), the model for end-stage liver disease score (P = 0.001), preoperative tracheal intubation (P = 0.001), ratio between arterial oxygen tension and fractional inspired oxygen (PaO₂/FiO₂ ratio) (P = 0.03), steroid therapy use (P = 0.001), lymphocyte count (P = 0.02), and cases requiring hemodiafiltration (P = 0.001) differed significantly between the two groups. Postoperative pneumonia occurred more frequently in emergency LDLT patients than in elective LDLT patients (P = 0.006). Invasive pulmonary aspergillosis (IPA) was the main cause of postoperative death in emergency LDLT patients, and, in a univariate analysis, a preoperative status of high serum (1 → 3)-β-d-glucan (>20 pg/ml, P = 0.001), advanced age (>52 years, P = 0.02), and a low PaO₂/FiO₂ ratio (<320, P = 0.01) were identified as factors predictive of IPA.

Conclusion

Careful perioperative management, including preoperative investigation of aspergillosis and empiric antibiotic therapy, should be considered for emergency LDLT patients who fulfill IPA risk factors.

A new treatment strategy for acute liver failure

Acute liver failure (ALF) is a syndrome defined by coagulopathy and encephalopathy and no effective treatments have been established, except for liver transplantation. However, considering the limited supply of donors, we should endeavor to prevent the progression of this syndrome in its early stage to improve the prognosis of patients with ALF. Recently, several authors have reported that over-activation of intrahepatic macrophages plays an important role in the progression of ALF and we have developed a new treatment method, transcatheter arterial steroid injection therapy (TASIT), to suppress macrophage activation. We have now used TASIT for 5 years and have found that TASIT is effective for patients with over-activation of macrophages in the liver but not for those with lesser activation of macrophages. Therefore, to identify the most appropriate patients for TASIT, we tried to categorize patients with ALF or acute liver injury according to markers for the degree of intrahepatic macrophage activation. This approach was helpful to select the appropriate treatment including liver transplantation. We believe that it is essential to analyze disease progression in each patient before selecting the most appropriate treatment.

A new prognostic formula for adult acute liver failure using computer tomography-derived hepatic volumetric analysis

BACKGROUND/AIMS

King's College Hospital (KCH) criteria and the model for end-stage liver disease (MELD) score are useful and widely-employed prognostic markers for acute liver failure (ALF). We previously reported that liver atrophy is an important prognostic factor for ALF. The aim of the present study was to assess the value of liver volumetry and to generate a new prognostic formula.

METHODS

Computed tomography-derived liver volume (CTLV) and standardized liver volume (SLV) of 30 adult ALF patients were calculated at the time of diagnosis. Patients were assigned to one of two groups: group A consisted of 13 patients who recovered without surgical intervention, and group B consisted of 17 patients who died due to liver failure or who underwent living donor liver transplantation (LDLT).

RESULTS

The median CTLV/SLV ratios of groups A and B were 1.019 and 0.757, respectively (P = 0.0009). The difference was most significant (P = 0.0002) at the probability cutoff point of 0.80 for CTLV/SLV ratio; the sensitivity and specificity were 76.5% and 92.3%, respectively. Serum total bilirubin (TB) levels and CTLV/SLV ratio were selected as independent prognostic factors by multivariate analysis. A prognostic formula including volumetric analysis was established: Z = -2.3813 - [0.15234 x TB (mg/dl)] + [4.5734 x CTLV/SLV] (AUC = 0.87783, P = 0.0002).

CONCLUSIONS

The CTLV/SLV ratio is a very useful marker for predicting the prognosis of adult ALF. Our prognostic formula including only the CTLV/SLV ratio and TB is simple and useful and awaits validation in a future larger-scale prospective study.

Acute liver failure and living donor liver transplantation

Acute liver failure (ALF) is defined by the presence of hepatic encephalopathy due to severe liver damage in patients without pre-existing liver disease. Although the mortality of ALF without liver transplantation is over 80%, the survival rates of ALF patients have improved considerably with the advent of liver transplantation, up to 60-80% in the last decade. Living donor liver transplantation (LDLT), which has mainly evolved in Asian countries where organ availability from deceased donors is extremely scarce, has also improved the survival rate of ALF patients. According to recent reports, the overall survival rate of adult ALF patients who underwent LDLT is 60% to 90%. Although there is still controversy regarding the graft type, the optimal graft volume, and ethical issues of defining the indications for LDLT in ALF patients with respect to donor risk, LDLT has become an established treatment option for ALF in areas where the use of deceased donors organs is severely restricted.

Living donor liver transplantation for fulminant hepatic failure

AIM

The aim of this study was to investigate the safety of living donor liver transplantation (LDLT) for fulminant hepatic failure (FHF) patients.

METHODS

We reviewed the clinical indications, operative procedures and prognosis of LDLT performed on patients with FHF at the University of Tokyo. From January 1996 to August 2007, 96 patients were referred to our department due to severe acute hepatitis or FHF. Of these, 36 underwent LDLT and were the subjects of this study. Of the 36 patients who underwent LDLT, 32 were over 18 years old. The etiologies of FHF included non-A, non-B hepatitis in 23, hepatitis B virus in 11, Wilson's disease in one, and auto-immune hepatitis in one. Graft type included right liver in 18, left liver in 16 and right paramedian sector in two.

RESULTS

Patient and graft survival rates at 5 years were 87% and 82%, respectively. Twenty-three patients had postoperative complications: acute cellular rejection in 12, biliary stricture in eight, bile leakage in six, peritoneal hemorrhage in six and hepatic arterial thrombosis in four.

CONCLUSION

The LDLT procedure provided satisfactory survival rates for FHF patients.

A new parameter using serum lactate dehydrogenase and alanine aminotransferase level is useful for predicting the prognosis of patients at an early stage of acute liver injury: a retrospective study

BACKGROUND

Although most patients with severe acute hepatitis are conservatively cured, some progress to acute liver failure (ALF) with a high rate of mortality. Based on the evidence that over-activation of macrophages, followed by disturbance of the hepatic microcirculation, plays a key role in ALF, we hypothesized that the production of serum lactate dehydrogenase (LDH) might increase in the liver under hypoxic conditions and could be an indicator to discriminate between conservative survivors and fatal patients at an early stage.

RESULTS

To confirm this hypothesis, we developed a new parameter with serum alanine aminotransferase (ALT) and LDH: the ALT-LDH index = serum ALT/(serum LDH - median of normal LDH range). We analyzed retrospectively 33 patients suffering acute liver injury (serum ALT more than 1000 U/L or prothrombin time expressed as international normalized ratio over 1.5 at admission) and evaluated the prognostic value of the ALT-LDH index, comparing data from the first 5 days of hospitalization with the Model for End-Stage Liver Disease (MELD) score. Patients whose symptoms had appeared more than 10 days before admission were excluded from this study. Among those included, 17 were conservative survivors, 9 underwent liver transplantation (LT) and 7 died waiting for LT. We found a rapid increase in the ALT-LDH index in conservative survivors but not in fatal patients. While the prognostic sensitivity and specificity of the ALT-LDH index was low on admission, at day 3 they were superior to the results of MELD.

CONCLUSION

ALT-LDH index was useful to predict the prognosis of the patients with acute liver injury and should be helpful to begin preparation for LT soon after admission.

Etiology and outcome of acute liver failure: retrospective analysis of 50 patients treated at a single center

BACKGROUND AND AIM

Acute liver failure (ALF) remains a devastating disease carrying considerable mortality. Since deceased donor liver transplantation is rarely performed in Japan, the artificial liver support system (ALS) and living donor liver transplantation (LDLT) are the main modalities used for treatment of ALF. The aim of this study was to analyze the outcome of ALF patients and to evaluate therapies for ALF according to etiology.

METHODS

Fifty consecutive patients with ALF were treated between January 1990 and December 2006. Prior to 1997, patients received ALS only. After 1997, ALS and/or LDLT were applied. LDLT was performed in 10 patients.

RESULTS

Four of 15 (27%) pre-1997 ALF patients survived, and 16 of 35 (46%) post-1997 ALF patients survived, including eight who underwent LDLT. The causes of ALF were acute hepatitis B virus (HBV) infection in 18%, severe acute exacerbation (SAE) of chronic HBV infection in 18%, autoimmune hepatitis (AIH) in 8%, and cryptogenic hepatitis in 44%. In total, 67% of the patients with ALF caused by acute HBV infection and AIH were cured without LDLT; only 11% of patients with ALF caused by SAE of HBV and 24% of cryptogenic hepatitis were successfully treated without LDLT. Notably, 80% of patients with cryptogenic hepatitis who underwent LDLT survived.

CONCLUSION

Since 1997, the survival rate of ALF patients has increased, mainly due to the introduction of LDLT. Liver transplantation should be performed especially in patients with ALF caused by SAE of HBV and cryptogenic hepatitis.

Methylprednisolone injection via the portal vein suppresses inflammation in acute liver failure induced in rats by lipopolysaccharide and d-galactosamine

BACKGROUND

We have reported that hepatic arterial steroid injection is an effective therapy to rescue patients from fulminant or severe acute hepatic failure. We speculate that a high concentration of steroid suppresses inflammatory processes in the liver directly by restraining activated inflammatory cells, including macrophages. To analyse the detailed mechanism, steroid injection via the portal vein was performed in an experimental model of liver damage.

METHODS

Rats subjected to lipopolysaccharide and d-galactosamine injection were treated with a methylprednisolone injection via the tail vein or the portal vein. The survival rate, serum levels of inflammatory cytokines and apoptotic cell counts in the liver were analysed.

RESULTS

The survival rate was significantly improved by steroid injection, especially via the portal vein. Serum values of alanine aminotransferase, tumor necrosis factor-alpha and interferon-gamma were reduced in the treated groups, especially the group given portal venous injections. Apoptotic cell counts in the liver were significantly lower in the group injected with steroid via the portal vein.

CONCLUSION

In the model rats, high concentrations of steroid in the liver acted on inflammatory cells and suppressed inflammatory cytokines and liver cell death. The mechanism is suggested to be the same for arterial steroid injection therapy in patients with acute hepatic failure.

Arterial steroid injection therapy can inhibit the progression of severe acute hepatic failure toward fulminant liver failure

AIM: To utilize transcatheter arterial steroid injection therapy (TASIT) via the hepatic artery to reduce hepatic macrophage activity in patients with severe acute hepatic failure.

METHODS: Thirty-four patients with severe acute hepatic failure were admitted to our hospital between June 2002 to June 2006 providing for the possibility of liver transplantation (LT). Seventeen patients were treated using traditional liver supportive procedures, and the other 17 patients additionally underwent TASIT with 1000 mg methylprednisolone per day for 3 continuous days.

RESULTS: Of the 17 patients who received TASIT, 13 were cured without any complications, 2 died, and 2 underwent LT. Of the 17 patients who did not receive TASIT, 4 were self-limiting, 7 died, and 6 underwent LT. Univariate logistic analysis revealed that ascites, serum albumin, prothrombin time, platelet count, and TASIT were significant variables for predicating the prognosis. Multivariate logistic regression analysis using stepwise variable selection showed that prothrombin time, platelet count, and TASIT were independent predictive factors.

CONCLUSION: TASIT might effectively prevent the progression of severe acute hepatic failure to a fatal stage of fulminant liver failure.

Liver transplantation for acute hepatic failure

There are numerous causes of acute hepatic failure (AHF). Cerebral edema, coagulopathy, renal failure, metabolic disturbances and infection are the main clinical sequelae. Patients with AHF should be stabilized when first encountered and transferred to the nearest liver transplant center, as AHF progresses quickly and is often fatal. There are few adequate medical interventions and care of patients with AHF is supportive until spontaneous recovery ensues. If recovery does not appear to occur, most causes of AHF are well accepted indications for liver transplantation.