Molecular adsorbent recirculating system dialysis in patients with acute liver failure who are assessed for liver transplantation

Bacterial and fungal infections: a frequent and deadly complication among critically ill acute liver failure patients

BACKGROUND

Acute liver failure (ALF) is a rare but life-threatening condition mostly requiring intensive care unit (ICU) admission. ALF induces immune disorders and may promote infection acquisition. However, the clinical spectrum and impact on patients' prognosis remain poorly explored.

METHODS

We conducted a retrospective single-centre study on patients admitted for ALF to the ICU of a referral University Hospital from 2000 to 2021. Baseline characteristics and outcomes according to the presence of infection until day 28 were analysed. Risk factors for infection were determined using logistic regression. The impact of infection on 28-day survival was assessed using the proportional hazard Cox model.

RESULTS

Of the 194 patients enrolled, 79 (40.7%) underwent infection: community-acquired, hospital-acquired before ICU and ICU-acquired before/without and after transplant in 26, 23, 23 and 14 patients, respectively. Most infections were pneumonia (41.4%) and bloodstream infection (38.8%). Of a total of 130 microorganisms identified, 55 were Gram-negative bacilli (42.3%), 48 Gram-positive cocci (36.9%) and 21 were fungi (16.2%). Obesity (OR 3.77 [95% CI 1.18-14.40]; p = .03) and initial mechanical ventilation (OR 2.26 [95% CI 1.25-4.12]; p = .007) were independent factors associated with overall infection. SAPSII > 37 (OR 3.67 [95% CI 1.82-7.76], p < .001) and paracetamol aetiology (OR 2.10 [95% CI 1.06-4.22], p = .03) were independently associated with infection at admission to ICU. On the opposite, paracetamol aetiology was associated with lower risk of ICU-acquired infection (OR 0.37 [95% CI 0.16-0.81], p = .02). Patients with any type of infection had lower day 28 survival rates (57% versus 73%; HR 1.65 [1.01-2.68], p = .04). The presence of infection at ICU admission (p = .04), but not ICU-acquired infection, was associated with decreased survival.

CONCLUSIONS

The prevalence of infection is high in ALF patients which is associated with a higher risk of death. Further studies assessing the use of early antimicrobial therapy are needed.

Adverse events, short- and long-term outcomes of extra corporeal liver therapy in the intensive care unit: 16 years experience with MARS® in a single center

Background

Molecular Adsorbent Recirculating System (MARS®) is a non-biological artificial liver device. The benefit risk ratio between uncertain clinical effects and potential adverse events remains difficult to assess. We sought to describe adverse events related to MARS® therapy as well as biological and clinical effects.

Methods

All intensive care unit (ICU) admissions to whom MARS® therapy was prescribed from March 2005 to August 2021 were consecutively and prospectively included. The main endpoint was the incidence of adverse events related to MARS® therapy. Secondary endpoints were the biological and clinical effects of MARS® therapy.

Results

We reported 180 admissions treated with MARS® therapy. Among the 180 admissions, 56 (31.1%) were for acute-on-chronic liver failure, 32 (17.8%) for acute liver failure, 28 (15.5%) for post-surgery liver failure, 52 (28.9%) for pruritus and 12 (6.7%) for drug intoxication. At least one adverse event occurred in 95 (52.8%) admissions. Thrombocytopenia was the most frequent adverse event which was recorded in 55 admissions (30.6%). Overall, platelets count was 131 (± 95) × 10⁹/L before and 106 (± 72) × 10⁹/L after MARS® therapy (p < .001). After MARS® therapy, total bilirubin was significantly decreased in all groups (p < 0.05). Hepatic encephalopathy significantly improved in both the acute-on-chronic and in the acute liver failure group (p = 0.01). In the pruritus group, pruritus intensity score was significantly decreased after MARS® therapy (p < 0.01).

Conclusion

In this large cohort of patients treated with MARS® therapy we report frequent adverse events. Thrombocytopenia was the most frequent adverse event. In all applications significant clinical and biological improvements were shown with MARS® therapy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-022-04165-z.

Use of intravenous N-acetylcysteine in acute severe hepatitis due to severe dengue infection: a case series

Background

Dengue fever is a common mosquito borne viral infection. Severe dengue fever associated severe hepatitis carries high mortality. Based on the beneficial effect of N-acetylcysteine (NAC) in paracetamol poisoning and non-acetaminophen induced liver failure, it is used in dengue fever associated hepatitis in clinical practice. We aim to study the reversal of liver enzymes with NAC in the setting of severe hepatitis due to severe dengue infection.

Methods

A retrospective analysis was conducted on hospitalized 30 adults with severe dengue fever with severe hepatitis. These 30 patients had aspartate transaminase (AST) and alanine transaminases (ALT) more than 500 U/L and/or PT INR (prothrombin time and international normalized ratio) more than 1.5. They were treated with NAC infusion of 100 mg/h for 3 to 5 days.

Results

The mean age of the group was 49.9 ± 11.46 years and 18 (60%) patients were males. Nineteen patients (63%) developed dengue shock. Of them 12 patients (40%) developed hepatic encephalopathy. Median AST on the day of administration of NAC was 1125 U/L interquartile range (IQR) 1653.25 while median ALT was 752 (IQR 459.25). There was a statistically significant reduction of both ALT (p = 0.034) and AST (p = 0.049) from day 1 to 4 after NAC infusion. Rise of platelet count between day 1 and day 4 also showed statistically significant difference (p = 0.011) but the reduction of prothrombin time and international normalized ratio (PT/INR) from 1 to day 4 did not show statistical significance difference. Mean duration of treatment with NAC was 3.61 ± 0.75 days while mean length of hospital stay was 6.2 ± 1.27 days. Only one patient died (3.3%). None of the patients reported adverse drug reaction due to NAC.

Conclusion

Majority of patients demonstrated marked clinical and biochemical improvements and they recovered fully. We observed faster and significant recovery of liver enzymes following administration of NAC. Based on the above findings, this study provides preliminary evidence for the beneficial effect of NAC in severe hepatitis in dengue infection with greater survival benefits.

Systematic review of MARS treatment in post-hepatectomy liver failure

BACKGROUND

Post-hepatectomy liver failure (PHLF) remains a serious complication after major liver resection with severe 90-day mortality. Molecular adsorbent recirculating system (MARS) is a potential treatment option in PHLF. This systematic review sought to analyze the experiences and results of MARS in PHLF.

METHODS

Following the PRISMA guidelines, a systematic literature review using PubMed and Embase was performed. Non-randomized trials were assessed by the MINORS criteria.

RESULTS

2884 records were screened and 22 studies were extracted (no RCT). They contained 809 patients including 82 patients with PHLF. Five studies (n = 34) specifically investigated the role of MARS in patients with PHLF. In these patients, overall 90-day survival was 47%. Patients with primary PHLF had significantly better 90-day survival compared to patients with secondary PHLF (60% vs 14%, p = 0.03) and treatment was started earlier (median POD 6 (range 2-21) vs median POD 30 (range 15-39); p < 0.001). Number of treatments differed non-significantly in these groups. Safety and feasibility of early MARS treatment following hepatectomy was demonstrated in one prospective study. No major adverse events have been reported.

CONCLUSION

Early MARS treatment is safe and feasible in patients with PHLF. Currently, MARS cannot be recommended as standard of care in these patients. Further prospective studies are warranted.

An evaluation of the usefulness of extracorporeal liver support techniques in patients with severe liver dysfunction

INTRODUCTION

The mortality rate in patients with severe liver dysfunction with no option of transplantation is unacceptably high. The main aim of this study was to evaluate the usefulness of applying extracorporeal liver support (ECLS) techniques in this group of patients.

MATERIAL AND METHODS

Data from hospital admissions of 101 patients with severe liver dysfunction who were admitted to the department of Anaesthesiology and intensive therapy between 2006 and 2015 were retrospectively analysed. The study group was divided into two subgroups. Standard Medical therapy (SMT) was a subgroup of patients receiving standard Medical therapy, and SMT + ECLS was a subgroup containing patients receiving standard medical therapy complemented by at least one extracorporeal liver support procedure.

RESULTS

Significantly lower intensive care unit (ICU) mortality and 30-day mortality rates were found in the SMT + ECLS subgroup (p = 0.0138 and p = 0.0238 respectively). No difference in 3-month mortality was identified between the two groups. In a multivariate model, independent risk factors for ICU mortality proved to be the SOFA score and prothrombin time. The highest discriminatory power for ICU mortality was demonstrated for the SOFA score, followed by APACHE II, SAPS II, MELD UNOS and GCS scores. For 30-day mortality, however, the best discriminatory power was shown for the SAPS II score, followed by SOFA, APACHE II, MELD UNOS and GCS scores.

CONCLUSIONS

Further studies are needed to assess the contribution of non-biological extracorporeal liver support procedures to a decrease in mortality rates in the population of patients with severe liver dysfunction.

Fabrication and in vitro evaluation of a packed-bed bioreactor based on an optimum two-stage culture strategy

A packed-bed (PB) bioreactor for bioartificial liver (BAL) was fabricated based on an optimum two-stage culture strategy and evaluated in vitro in this research. Human induced hepatocytes (hiHeps) were first expanded using Cytodex 3 microcarriers and the choice of microcarrier concentration and fetal bovine serum (FBS) content was optimized. Then, the cells expanded under the optimum expansion condition were perfused into a perfusion system containing Fibra-Cel (FC) disks to fabricate a PB bioreactor. Operating parameters including flow rate and seeding density for perfusion culture were optimized, respectively. Results indicated that during suspension culture, rapid cell proliferation and favorable amino acid metabolism were achieved at 3 mg/mL microcarriers combined with 1% FBS. While for the perfusion culture, the most effective flow rate and seeding density were 2 mL/min and 1 × 10⁶ cells/mL, respectively. Under this optimum perfusion condition, hiHeps showed good proliferation ability, high viability, homogeneous distribution, high metabolism activities and efficient albumin secretion as well as high liver-specific genes expression. Therefore, the two-stage culture strategy based on operating parameters optimization provides a new method for the development of PB bioreactors.

Molecular adsorbent recirculating system (MARS) in acute liver injury and graft dysfunction: Results from a case-control study

Background

The primary therapeutic goals in the treatment of liver injury are to support liver regeneration or bridge the gap to liver transplantation (LT). Molecular adsorbent recirculating system (MARS) therapy has shown beneficial effects for specific symptoms of liver failure; however, general survival advantages have not yet been demonstrated.

Aim

We studied the effects of MARS therapy compared to standard medical treatment (SMT) in two patient cohorts: in patients with an acute liver injury and in those with graft dysfunction (GD).

Methods

We report on our experience over a 6.5-year period with 73 patients treated with SMT or with SMT and MARS (MARS group). In total, 53 patients suffered from acute liver injury in their native liver without a preexisting liver disease (SMT: n = 31, MARS: n = 22), and 20 patients showed a severe GD after LT (SMT: n = 10, MARS: n = 10).

Results

The entire cohort was predominantly characterized by hemodynamically and respiratorily stable patients with a low hepatic encephalopathy (HE) grade and a model of end-stage liver disease (MELD) score of 20.57 (MARS) or 22.51 (SMT, p = 0.555). Within the MARS group, the median number of extracorporeal therapy sessions was four (range = 3–5 sessions). Independent of the underlying etiology, MARS improved the patients’ bilirubin values in the short term compared to SMT alone. In patients with acute liver injury, this response was sustained even after the end of MARS therapy. By contrast, the majority of patients with GD and an initial response to MARS therapy experienced worsened hyperbilirubinemia. No differences in 28-day mortality were observed with respect to acute liver injury (MARS 5.3% (95% CI: 0–15.3); SMT 3.3% (95% CI: 0–9.8), p = 0.754) or GD (MARS 20.0% (95% CI: 0–44.7), SMT 11.1% (95% CI: 0–31.7), p = 0.478).

Conclusions

Although it did not improve 28-day mortality, MARS therapy improved the short-term response in patients with acute liver injury as well as in those with GD. In cases of acute hepatic injury, the use of MARS therapy resulted in the sustained stabilization of liver function and improved liver regeneration. A short-term response to MARS may predict the future course of the disease.

Use of the molecular adsorbent recirculating system (MARS™) for the management of acute poisoning with or without liver failure

INTRODUCTION

There is an increasing interest in recent developments in bioartificial and non-bioartificial devices, so called extracorporeal liver assist devices, which are now used widely not only to increase drug elimination, but also to enhance the removal of endogenous substances in acute liver failure. Most of the non-bioartificial techniques are based on the principle of albumin dialysis. The objective is to remove albumin-bound substances that could play a role in the pathophysiology of acute liver failure by dialysing blood against an albumin-containing solution across a high flux permeable membrane. The most widely used device is the Molecular Adsorbent Recirculating System (MARS™).

METHODS

The relevant English and French literature was identified through Medline using the terms, 'molecular adsorbent recirculating system', 'MARS', 'acute liver failure', 'acute poisoning', 'intoxication'. This search identified 139 papers of which 48 reported on a toxic cause for the use of MARS™. Of these 48 papers, 39 specified the substance (eighteen different substances were identified); two papers reported on the same group of patients. BIOARTIFICIAL AND NON-BIOARTIFICIAL SYSTEMS: Bioartificial systems based on porcine hepatocytes incorporated in the extracorporeal circuit are no longer in use due to the possibility of porcine retroviral transmission to humans. Historically, experience with such devices was limited to a few cases of paracetamol poisoning. In contrast, an abundant literature exists for the non-bioartificial systems based on albumin dialysis. The MARS™ has been used more widely than other techniques, such as the one using fractionated plasma separation and adsorption (Prometheus™). All the extracorporeal liver assist devices are able to some extent to remove biological substances (ammonia, urea, creatinine, bilirubin, bile acids, amino acids, cytokines, vasoactive agents) but the real impact on the patient's clinical course has still to be determined. Improvement in cardiovascular or neurological dysfunction has been shown both in acute liver failure and acute-on-chronic liver failure but no impact on mortality has been reported. ACUTE POISONING WITH LIVER FAILURE: Randomized controlled trials are very limited in number and patients poisoned by paracetamol or Amanita phalloides are usually included for outcome analysis in larger groups of acute liver failure patients. Initial results look promising but should be confirmed. Beyond its effect in liver failure, MARS™ could also enhance the elimination of the drug or toxin responsible for the failure, as is described with paracetamol. ACUTE POISONING WITHOUT LIVER FAILURE: Extracorporeal liver assist devices have also been used to promote elimination of drugs that are highly protein bound. Data in various case reports confirm a high elimination of phenytoin, theophylline and diltiazem. However, definite conclusions on the toxicokinetic or clinical efficacy cannot be drawn.

CONCLUSIONS

Despite the lack of large multicentre randomized trials on the use of MARS™ in patients with acute liver failure, the literature shows clinical and biological benefit from this technique. In drug or toxin-induced acute liver failure, such as paracetamol or mushroom poisoning, MARS™ has been used extensively, confirming in a non-randomized fashion, the positive effect observed in the larger population of acute liver failure patients. Furthermore, as MARS™ has been shown in experimental studies to remove protein-bound substances, it is potentially a promising treatment for patients with acute poisoning from drugs that have high protein-binding capacity and are metabolized by the liver, especially, if they develop liver failure concomitantly.

Acute-on-chronic liver failure: extracorporeal liver assist devices

PURPOSE OF REVIEW

Acute-on-chronic liver failure (ACLF), a syndrome precipitated by acute liver injury in patients with advanced cirrhosis, is associated with multiorgan dysfunction and high rates of mortality. Liver support systems have been developed in an attempt to improve survival of patients with ACLF by providing a bridge until recovery of the native liver function.

RECENT FINDINGS

Nonbiological devices such as molecular adsorbent recirculating system (MARS) and fractionated plasma separation and adsorption (Prometheus) are effective in improving severe hepatic encephalopathy and cholestasis, have good safety and tolerability profiles and are frequently employed in patients with ACLD; however, randomized controlled trials (RCTs) failed to show improvement in survival. Biologic devices that incorporate hepatic cells in bioreactors are also under development. Recent data from pilot studies suggested improvement in survival rates in some groups of patients with ACLF; however, their effect on patient survival in RCT is still unknown.

SUMMARY

Liver support systems are safe and well tolerated when used in management of patients with ACLF. Their use should continue in controlled clinical trials to explore their role in bridging patients to liver transplantation or recovery in well defined patient groups.

Bridging Therapies and Liver Transplantation in Acute Liver Failure; 10 Years of MARS Experience from Finland

Acute liver failure is a life-threatening condition in the absence of liver transplantation option. The aetiology of liver failure is the most important factor determining the probability of native liver recovery and prognosis of the patient. Extracorporeal liver assist devices like MARS (Molecular Adsorbent Recirculating System) may buy time for native liver recovery or serve as bridging therapy to liver transplantation, with reduced risk of cerebral complications. MARS treatment may alleviate hepatic encephalopathy even in patients with a completely necrotic liver. Taking this into account, better prognostic markers than hepatic encephalopathy should be used to assess the need for liver transplantation in acute liver failure.

Liver transplantation avoided in patients with fulminant hepatic failure who received albumin dialysis with the molecular adsorbent recirculating system while on the waiting list: impact of the duration of therapy

Eighteen patients with fulminant hepatic failure due to various medical causes were listed for emergency liver transplantation and treated with extracorporeal albumin dialysis sessions using the molecular adsorbent recirculating system (MARS) at our center over a 74-month period. Due to improvement of liver function, transplantation could be avoided in 9 patients (50%, 95% confidence interval 29% to 71%) who fully recovered afterwards. This improvement rate was higher than the rate of improvement in the French cohort of fulminant hepatic failure patients with similar etiologies (19.3%, 95% confidence interval 14.9% to 24.6%, P = 0.002). In our 18 patients, there were no statistically significant differences in any baseline characteristics or in the time with liver failure meeting transplant criteria between the patients who improved while waiting and those who did not. However, the patients who improved received a greater number of sessions and a longer total duration of MARS therapy (all P < 0.001). In the whole study population, a MARS therapy duration > or =15 h was significantly associated with improvement of liver function without transplantation (adjusted adds ratio [OR] 65.76, 2.48-1743.11, P = 0.01). Tolerance of therapy was acceptable. These results suggest that MARS therapy could contribute to native liver recovery and is safe in patients on the waiting list for fulminant hepatic failure. A minimum duration of therapy (> or =15 h) could be necessary to expect significant liver function improvement.

Albumin dialysis in liver failure: comparison of molecular adsorbent recirculating system and single pass albumin dialysis--a retrospective analysis

Despite improvement in critical care, liver failure is still associated with high mortality. Therapeutic concepts are aimed at restoring endogenous liver function or to bridge the time to liver transplantation. In addition to standard medical treatment, extracorporeal liver support with albumin dialysis is used for this purpose. The aim of this study was to analyze the efficacy of single pass albumin dialysis (SPAD) in comparison to the molecular adsorbent recirculating system (MARS) in patients treated at our university hospital intensive care unit between July 2004 and August 2008. In this retrospective analysis we studied patients presenting with liver failure who were treated with albumin dialysis. Laboratory parameters, daily health scoring, the number of transfusions, and mortality were recorded. The (paired) t-test, Mann-Whitney U-test, and Wilcoxon test were used for statistical analysis. In all, 163 albumin dialysis treatments, 126 with MARS and 37 with SPAD, in 57 patients were performed. MARS resulted in a significant decrease in bilirubin (-38 +/- 66.5 micromol/L from a baseline of 301 +/- 154.6 micromol/L), gamma-glutamyltransferase (gamma-GT), alanine aminotransferase, creatinine, and urea. SPAD resulted in a significant decrease in bilirubin (-41 +/- 111.2 micromol/L from a baseline of 354 +/- 189.4 micromol/L) and gamma-GT, while lactate levels increased. No differences in the need for blood transfusion, health scoring, or mortality between the two treatment modalities were detected. This retrospective analysis suggests equal efficacy of MARS and SPAD; however, prospective assessment to further define the role of SPAD in the treatment of acute or acute-on-chronic liver failure is needed.

Management of acute liver failure

Acute liver failure (ALF) is a syndrome of diverse etiology, in which patients without previously recognized liver disease sustain a liver injury that results in rapid loss of hepatic function. Depending on the etiology and severity of the insult, some patients undergo rapid hepatic regeneration and spontaneously recover. However, nearly 60% of patients with ALF in the US require and undergo orthotopic liver transplantation or die. Management decisions made by clinicians who initially assess individuals with ALF can drastically affect these patients' outcomes. Even with optimal early management, however, many patients with ALF develop a cascade of complications often presaged by the systemic inflammatory response syndrome, which involves failure of nearly every organ system. We highlight advances in the intensive care management of patients with ALF that have contributed to a marked improvement in their overall survival over the past 20 years. These advances include therapies that limit the extent of liver injury and maximize the likelihood of spontaneous recovery and approaches to enable prevention, recognition and early treatment of complications that lead to multi-organ-system failure, the most common cause of death. Finally, we summarize the role of orthotopic liver transplantation in salvage of the most severely affected patients.

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.

[Fulminant and subfulminant hepatitis: causes and treatment]

Fulminant hepatitis is an emergency because within a few hours, the physician must find the cause of the hepatitis (not identified in 15 to 20% of cases), rule out any contraindication to liver transplantation, verify that it is indicated, and prevent and/or treat the complications associated with liver failure. Viruses (especially hepatitis viruses A and B), drugs, and toxic agents are the most common causes of fulminant hepatitis, with the proportions varying between countries. Hepatitis viruses, the leading cause through 1995-1996, have fallen behind drugs and in particular paracetamol, which is now the leading cause of this disease in Europe and in the United States. There are also other rarer causes: other viruses (e.g., herpes virus HSV1 or 2, hepatitis virus E, parvovirus B19, and chickenpox-herpes zoster), Wilson Disease, acute Budd-Chiari and Reyes syndromes, autoimmune hepatitis, neoplastic infiltration of the liver, hypoxic hepatitis, heatstroke, acute pregnancy-related steatosis, and the HELLP syndrome. Prognosis is essentially determined by neurological status, but is also affected very rapidly by damage to other organs. Liver transplantation has revolutionized the prognosis of fulminant hepatitis, causing survival to increase from 10-20% (all causes combined) to 75-80% at 1 year and 70% at 5 years. These patients can be treated only in specialized centers with access to liver transplantation and to different modern means of liver resuscitation (hypothermia, artificial liver support, albumin dialysis, monitoring intracranial pressure and cerebral perfusion, etc.) -all from the onset of the disease.

Survival predictors in patients treated with a molecular adsorbent recirculating system

AIM: To identify prognostic factors for survival in patients with liver failure treated with a molecular adsorbent recirculating system (MARS).

METHODS: MARS is a liver-assisting device that has been used in the treatment of liver failure to enable native liver recovery, and as a bridge to liver transplantation (LTX). We analyzed the 1-year outcomes of 188 patients treated with MARS, from 2001 to 2007, in an intensive care unit specializing in liver disease. Demographic, clinical and laboratory parameters were recorded before and after each treatment. One-year survival and the number of LTXs were recorded. Logistic regression analysis was performed to determine factors predicting survival.

RESULTS: The study included 113 patients with acute liver failure (ALF), 62 with acute-on-chronic liver failure (AOCLF), 11 with graft failure (GF), and six with miscellaneous liver failure. LTX was performed for 29% of patients with ALF, 18% with AOCLF and 55% with GF. The overall 1-year survival rate was 74% for ALF, 27% for AOCLF, and 73% for GF. The poorest survival rate, 6%, was noted in non-transplanted patients with alcohol-related AOCLF and cirrhosis, whereas, patients with enlarged and steatotic liver had 55% survival. The etiology of liver failure was the most important predictor of survival (P < 0.0001). Other prognostic factors were encephalopathy (P = 0.001) in paracetamol-related ALF, coagulation factors (P = 0.049) and encephalopathy (P = 0.064) in non-paracetamol-related toxic ALF, and alanine aminotransferase (P = 0.013) and factor V levels (P = 0.022) in ALF of unknown etiology.

CONCLUSION: The etiology of liver disease was the most important prognostic factor. MARS treatment appears to be ineffective in AOCLF with end-stage cirrhosis without an LTX option.

Molecular adsorbent recirculating system (Mars) in patients with primary nonfunction and other causes of graft dysfunction after liver transplantation in the era of extended criteria donor organs

Liver dysfunction is an important cause of morbidity and mortality after orthotopic liver transplantation (OLT). The Molecular Adsorbent Recirculating System (MARS) is an albumin-based dialysis system designed to enhance the excretory function of a failing liver. MARS has been successfully used in patients affected by advanced liver disease and presenting with severe cholestasis. The aim of this study was to evaluate the safety and clinical efficacy of MARS in patients with liver dysfunction after OLT. Seven patients (primary nonfunction, 2 patients; graft dysfunction, 5 patients) fulfilled the inclusion criteria of serum bilirubin level >15 mg/dL and least 1 of the following clinical signs: hepatic encephalopathy (HE) > or = grade II, hepatorenal syndrome (HRS), and intractable pruritus. Graft and patient survival rates at 6 months were 42.8% and 57.1%, respectively. All patients tolerated MARS treatment, with no adverse event. In all patients, a decrease in serum bilirubin (P < .05), bile acids (P < .05), serum creatinine, and ammonia levels was observed after treatment with MARS. A considerable improvement of HE, as well as renal and synthetic liver functions, was observed in 4 of 5 patients with graft dysfunction, but not among those with primary nonfunction. The patients with intractable pruritus showed significant improvement of this symptom after MARS therapy. Thus, MARS is a safe, therapeutic option for the treatment of liver dysfunction after OLT. Further studies are necessary to confirm whether this treatment is able to improve both graft and patient survival.

Report of the Paris consensus meeting on expanded criteria donors in liver transplantation

Because of organ shortage and a constant imbalance between available organs and candidates for liver transplantation, expanded criteria donors are needed. Experience shows that there are wide variations in the definitions, selection criteria, and use of expanded criteria donors according to different geographic areas and different centers. Overall, selection criteria for donors have tended to be relaxed in recent years. Consensus recommendations are needed. This article reports the conclusions of a consensus meeting held in Paris in March 2007 with the contribution of experts from Europe, the United States, and Asia. Definitions of expanded criteria donors with respect to donor variables (including age, liver function tests, steatosis, infections, malignancies, and heart-beating versus non-heart-beating, among others) are proposed. It is emphasized that donor quality represents a continuum of risk rather than "good or bad." A distinction is made between donor factors that generate increased risk of graft failure and factors independent of graft function, such as transmissible infectious disease or donor-derived malignancy, that may preclude a good outcome. Updated data concerning the risks associated with different donor variables in different recipient populations are given. Recommendations on how to safely expand donor selection criteria are proposed.

Acetaminophen-induced acute liver failure treated with single-pass albumin dialysis: report of a case

BACKGROUND

Acetaminophen (paracetamol) overdose is a leading cause of acute liver failure (ALF). When patients fulfill the King's College criteria for acetaminophen-induced ALF (AALF), they have a poor prognosis for survival without liver transplantation. Recent advances in artificial liver support have used albumin as a binding and scavenging molecule in ALF. One method, single-pass albumin dialysis (SPAD), involves dialyzing blood against an albumin-containing solution across a high-flux membrane to remove albumin-bound toxins. Herein, we describe our protocol for SPAD and report its use in a case of AALF as a bridge to native liver recovery.

CASE

A 41-year-old female with no documented history of liver disease presented with acute acetaminophen toxicity and developed hepatic encephalopathy, coagulopathy and lactic acidosis. The patient met King's College criteria for liver transplantation, based on pH and INR, but was deemed not suitable as a candidate due to psychosocial comorbidities. On day 3 of her ICU admission, she received the first of five consecutive daily runs (total ~77 hours) of SPAD. The patient's course was complicated by cerebral edema requiring mannitol. She was extubated on day 11 and transferred to the ward by day 13. At ICU discharge, her liver function (INR 1.9, bilirubin 435 mmol/L) and kidney function were recovering. She did not have any long-term neurological sequelae. By hospital discharge (day 46) her native liver function had recovered with a bilirubin <100mmol/L.

CONCLUSION

We describe a case of a patient with acetaminophen-induced acute liver failure who was successfully bridged to spontaneous native liver recovery as a result of SPAD treatment. In patients with ALF, SPAD may be an additional intervention for temporary extracorporeal support. Further investigation in larger prospective studies is warranted.

The effect of molecular adsorbent recirculating system treatment on survival, native liver recovery, and need for liver transplantation in acute liver failure patients

Acute liver failure (ALF) is a medical emergency. Molecular adsorbent recirculating system (MARS), an artificial liver support system, can partly compensate for the detoxifying function of the liver by removing toxins from blood. To analyze the efficacy of MARS treatment, the outcomes of 113 ALF patients, treated with MARS between 2001 and 2007, were compared with a historical control group of 46 ALF patients treated without MARS between 1995 and 2001. Overall survival of transplanted patients was 94% in the MARS group and 77% in the control group (P=0.06). Without transplantation, survival was 66% and 40% (P=0.03), respectively. However, the etiological distribution of ALF differed significantly between the groups. In ALF patients with unknown etiology, groups were comparable at baseline; 91% and 69% of transplanted patients survived the MARS and control groups and the native liver recovered in 20% and 8% of the patients, respectively. Of the originally nonencephalopathic patients of unknown etiology, 36% underwent liver transplantation in the MARS group compared to 100% in the control group. Interpretation of the results was difficult in toxic etiology patients on account of differing baseline statuses. MARS treatment might partly explain the trend toward increased survival of ALF patients with unknown etiology.

Effect of Prometheus liver assist system on systemic hemodynamics in patients with cirrhosis: A randomized controlled study

AIM: To evaluate treatment safety and hemodynamic changes during a single 6-h treatment with the Prometheus™ liver assist system in a randomized, controlled study.

METHODS: Twenty-four patients were randomized to either the study group or to one of two control groups: Fractionated Plasma Separation Adsorption and Dialysis, Prometheus™ system (Study group; n = 8); Molecular Adsorbent Recirculation System (MARS)™ (Control group 1, n = 8); or hemodialysis (Control group 2; n = 8). All patients included in the study had decompensated cirrhosis at the time of the inclusion into the study. Circulatory changes were monitored with a Swan-Ganz catheter and bilirubin and creatinine were monitored as measures of protein-bound and water-soluble toxins.

RESULTS: Systemic hemodynamics did not differ between treatment and control groups apart from an increase in arterial pressure in the MARS group (P = 0.008). No adverse effects were observed in any of the groups. Creatinine levels significantly decreased in the MARS group (P = 0.03) and hemodialysis group (P = 0.04). Platelet count deceased in the Prometheus group (P = 0.04).

CONCLUSION: Extra-corporal liver support with Prometheus is proven to be safe in patients with end-stage liver disease but does not exert the beneficial effects on arterial pressure as seen in the MARS group.

Liver support devices

PURPOSE OF REVIEW

Liver support devices are used either as a bridge to liver transplantation or liver recovery in patients with acute or acute-on-chronic liver failure. The review analyzes the recent literature and asks if the current enthusiasm for these devices is justified.

RECENT FINDINGS

Many liver support devices exist and are discussed. Clinical data on artificial devices are rapidly emerging, especially on the molecular adsorbents recirculating system, and fractionated plasma separation and adsorption (Prometheus). While hepatic encephalopathy is improved by the molecular adsorbents recirculating system and probably Prometheus too, neither system has been shown to improve survival. Less clinical data exist for bioartificial support devices. These may use human hepatocytes, such as the extracorporeal liver assist device, although most devices use porcine hepatocytes, such as HepatAssist.

SUMMARY

Enthusiasm in liver support devices is justified as many nonrandomized studies have suggested some biochemical and clinical benefits. The results of several ongoing multicenter randomized controlled trials are anxiously awaited. Meanwhile, because mortality without liver transplantation remains high despite the use of liver support devices, these devices should only be used in the research setting or by experts proficient in their use and as a bridge to liver transplantation rather than liver recovery.

Bench-to-bedside review: current evidence for extracorporeal albumin dialysis systems in liver failure

Acute liver failure (ALF) and acute on chronic liver failure (AoCLF) carry a high mortality. The rationale for extracorporeal systems is to provide an environment facilitating recovery or a window of opportunity for liver transplantation. Recent technologies have used albumin as a scavenging molecule. Two different albumin dialysis systems have been developed using this principle: MARS (Molecular Adsorbent Recirculation System) and SPAD (Single-Pass Albumin Dialysis). A third system, Prometheus (Fractionated Plasma Separation and Adsorption), differs from the others in that the patient's albumin is separated across a membrane and then is run over adsorptive columns. Although several trials have been published (particularly with MARS), currently there is a lack of controlled studies with homogenous patient populations. Many studies have combined patients with ALF and AoCLF. Others have included patients with different etiologies. Although MARS and Prometheus have shown biochemical improvements in AoCLF and ALF, additional studies are required to show conclusive benefit in short- and long-term survival. The appropriate comparator is standard medical therapy rather than head-to-head comparisons of different forms of albumin dialysis.

Acute liver failure: liver support therapies

PURPOSE OF REVIEW

We summarize the therapeutic approach to patients with acute liver failure with the main focus on bioartificial and artificial liver support. We also describe specific and general therapeutic approaches based upon recent advances in the understanding of the pathophysiology of acute liver failure.

RECENT FINDINGS

Bioartificial liver support systems use hepatocytes in an extracorporeal device connected to the patient's circulation. Artificial liver support is intended to remove protein-bound toxins and water-soluble toxins without providing synthetic function. Both systems improve clinical and biochemical parameters and can be applied safely to patients. Although bioartificial liver-assist devices have not been shown to improve the survival of patients with acute liver failure, further development is underway. Artificial liver support systems have been shown to alter several pathophysiological mechanisms involved in the development of acute liver failure but survival data are still limited.

SUMMARY

Mortality in patients with acute liver failure is still unacceptably high. The most effective treatment, liver transplantation, is a limited resource and so other therapeutic options to bridge patients to recovery or stabilization have to be considered. Better understanding of the pathophysiology of acute liver failure and device development is necessary to achieve the elusive goal of effective extracorporeal liver assist.