Review article: the molecular adsorbents recirculating system (MARS) in liver failure

Kidney Outcomes Following Utilization of Molecular Adsorbent Recirculating System

Introduction

Molecular adsorbent recirculating system (MARS) is an extracorporeal system combining conventional veno-venous hemodiafiltration and adsorption to provide rescue support in fulminant hepatic failure. Acute kidney injury (AKI) is common in patients with hepatic failure warranting continuous kidney replacement therapy (CKRT). Our primary aim was to characterize a cohort of patients who received MARS therapy and examine kidney events given the current paucity of available data.

Methods

Patients initiating MARS in a tertiary care setting from January 2014 through December 2020 were assessed for treatment indications, transplantation, CKRT, kidney recovery, and death. Data was collected using the REDCAP software.

Results

A total of 49 patients (67% female; 75% White) received MARS therapy with 29 patients (59%) requiring concomitant CKRT. Hepatic encephalopathy (HE) was the most common indication for MARS initiation (55%). In-hospital mortality was 41% (12/29) among patients who received CKRT versus 10% (2/20) among those not requiring CKRT (relative risk [RR] 4.15, 95% confidence interval [CI] 1.04 to 16.52, P = 0.044); this persisted following adjustment for prespecified patient characteristics (all RR ≥ 3.76, all P ≤ 0.060). One-year mortality post-MARS initiation was high overall but highest among the CKRT group (59% [17/29] vs. 25% [5/20] unadjusted RR 2.92, 95% CI 1.08 to 7.94, P = 0.035). Liver transplant after MARS occurred in 41% of patients (20/49). After CKRT, 39% of patients (9/29) recovered kidney function prior to hospital discharge.

Conclusions

Patients requiring MARS frequently have AKI warranting the use of concomitant CKRT, which is associated with a high rate of in-hospital and 1-year mortality.

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.

Bilirubin Removal from Albumin - Containing Solution by Adsorption on Polymer Resin

Adsorption equilibrium of bilirubin onto polymeric resins is studied. Solutions containing albumin are used in order to simulate the behavior of systems for removal of albumin-bound substances from blood, serum or dialysis fluids. The effect of albumin pre-loading on the resin is also analysed. Results are explained by a chemically based model that accounts for binding reaction between albumin and bilirubin in the liquid phase.

Thermodynamic equilibria and physical models are essential tools for designing adsorption columns aimed at detoxification treatments.

The role of the Molecular Adsorbents Recirculating System (MARS) in the management of liver failure

Albumin-bound toxins accumulate in liver failure, and are believed to contribute to the development of the associated end-organ dysfunctions (kidney, circulation, brain). The scavenging functions of albumin are utilized in albumin dialysis for toxin removal. The Molecular Adsorbents Recirculating System (MARS) is an extracorporeal liver support device based on dialysis across an albumin-impregnated membrane, using 20% albumin as dialysate. Charcoal and anion exchange resin columns in the circuit help cleanse and regenerate the dialysate. Clinical studies over the last decade have demonstrated proven reduction in hyperbilirubinaemia, along with an improvement in hepatic encephalopathy, systemic haemodynamics and renal function in liver failure patients, as well as apparent improvement in survival. However, the specific mechanisms underlying these observed clinical changes are as yet unclear. The results of larger controlled clinical trials, as well as studies investigating the pathophysiological basis of its effect, are awaited.

Hepatorenal Syndrome: Diagnosis and Treatment - newsreel

Hepatorenal syndrome (HRS) is defined as renal failure that occurs in the presence of severe acute or chronic liver disease in the absence of underlying renal pathology. Due to the functional nature of the disease and the absence of specific diagnostic markers, HRS diagnosis is determined based on positive criteria associated with excluding other causes of renal failure in patients with liver cirrhosis and ascites. Differentiation from other types of acute or chronic renal disease is extremely difficult and therapeutic options are limited, prophylactic behavior is most appropriate in patients with severe hepatic disease and risk factors for the installation of hepatorenal syndrome. Highlighting all precipitating factors of acute renal insufficiency and therapeutic modalities in order to minimize adverse events is an important step in improving the follow-up of the patients with liver cirrhosis. The prognosis is reserved especially for type 1 HRS. Liver transplantation is the best option for patients without contraindications. The therapies introduced in recent years, such as vasoconstrictor drugs or transjugular intrahepatic portosystemic shunt are effective methods in the renal function improvement.

Albumin dialysis in artificial liver support systems: open-loop or closed-loop dialysis mode?

In artificial liver support systems, the open-loop albumin dialysis mode (OLM) is usually used to remove protein-bound toxins from the blood of patients with liver failure. However, there is still interest in the closed-loop albumin dialysis mode (CLM) because this mode may enable not only the regeneration and reuse of albumin but also the miniaturization of artificial liver systems. In this article, we compared the two modes under a fixed amount of albumin in dialysate experimentally and theoretically. The results show that according to the detoxification efficiency in the 3 hour dialysis for removing albumin-bound bilirubin, CLM is better than OLM. The usage efficiency of albumin in CLM is also higher. Moreover, the advantage of CLM is more significant when the concentration of bilirubin in blood is lower. Under a given amount of albumin in dialysate, if the concentration of bilirubin in blood is high, one may further increase the performance of CLM by means of increasing the flow rate of the albumin dialysate or using the highly concentrated albumin dialysate.

Development of a multifunctional detoxifying unit for liver failure patients

BACKGROUND/AIMS

Extracorporeal blood detoxification strategies aimed at supporting impaired liver function have been explored because of the imbalance between donor organs and waiting patients. A limited number of artificial devices are now available clinically, and these are characterized by the use of multistage adsorption procedures in conjunction with hemodialysis, but these features simultaneously increase system complexity and treatment costs.

METHODS

The authors developed a simpler strategy for liver dialysis based on the use of a multifunctional filter, which enables plasma separation and perfusion in a single unit.

RESULTS

Liver dialysis treatments were successfully performed using the devised unit when bovine blood containing uremic and hepatic toxins was circulated. Removal of the solutes under investigation was significant, and reduction ratios of 78% for urea, 98% for creatinine and 91% for bilirubin were achieved. Plasma free hemoglobin levels were reasonably maintained despite prolonged blood recirculation for 5 h, and platelet, hematocrit and hemoglobin levels remained uniform throughout liver dialysis sessions.

CONCLUSION

The devised liver support unit may offer a straightforward and efficient means of cleansing blood for patients with hepatic failure.

Liver transplantation for Wilson disease

The aim of this paper is to review the current status of liver transplantation (LT) for Wilson disease (WD), focusing on indications and controversies, especially in patients with neuropsychiatric disease, and on identification of acute liver failure (ALF) cases related to WD. LT remains the treatment of choice for patients with ALF, as initial presentation of WD or when anti-copper agents are stopped, and for patients with chronic liver disease progressed to cirrhosis, unresponsive to chelating medications or not timely treated with copper chelating agents. The indication for LT in WD remains highly debated in patients with progressive neurological deterioration and failure to improve with appropriate medical treatment. In case of Wilsonian ALF, early identification is key as mortality is 100% without emergency LT. As many of the copper metabolism parameters are believed to be less reliable in ALF, simple biochemical tests have been proposed for diagnosis of acute WD with good sensitivity and specificity. LT corrects copper metabolism and complications resulting from WD with excellent 1 and 5 year survival. Living related liver transplantation represents an alternative to deceased donor LT with excellent long-term survival, without disease recurrence. Future options may include hepatocyte transplantation and gene therapy. Although both of these have shown promising results in animal models of WD, prospective human studies are much needed to demonstrate their long-term beneficial effects and their potential to replace the need for medical therapy and LT in patients with WD.

Influence of albumin dialysis on pharmacokinetics of amphotericin B colloidal dispersion and amphotericin B lipid complex

Albumin dialysis (AD) is a therapeutic option in severe cholestatic liver failure. However, it can significantly enhance drug elimination. Pharmacokinetic data on antimicrobial agents--in particular on antimycotics--administered under this clinical condition are very sparse. Therefore, amphotericin B (AMB) plasma concentrations were measured in two critically ill patients who were treated with AD because of severe cholestatic liver failure and were prescribed lipid formulated AMB--either AMB colloidal dispersion (ABCD) or AMB lipid complex (ABLC)--for suspected invasive fungal infection. AD was performed with the molecular adsorbent recirculating system (MARS). Lipid-associated and liberated AMB were separately quantified on and off AD. The clearance of the liberated AMB fraction was not essentially affected (ABLC) or moderately enhanced during AD by a factor of 2.5 (ABCD). The clearance of the lipid-formulated fraction was increased by a factor of 4 during AD (ABCD) or was similar (ABLC) on and off AD. Despite the fact that there was a four-fold higher clearance of the lipid-formulated fraction of ABCD, the clinically relevant area under the concentration time curve of the liberated AMB fraction was only moderately changed (by 37% in ABCD, 70% in ABLC) during AD. Thus, the effect of AD on lipid formulated AMB appears to be moderate. A daily dose of 5 mg/kg will probably lead to adequate plasma levels in patients on AD.

IL-1 or TNF receptor gene deletion delays onset of encephalopathy and attenuates brain edema in experimental acute liver failure

Previous reports suggested that brain-derived proinflammatory cytokines are involved in the pathogenesis of hepatic encephalopathy (HE) and brain edema in acute liver failure (ALF). To further address this issue, expression of interleukin-1beta (IL-1beta), tumor necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) mRNAs were measured in the brains of mice with acute liver failure resulting from exposure to azoxymethane. In addition, time to severe encephalopathy (coma) was assessed in mice lacking genes coding for interferon-gamma, the tumor necrosis factor receptor-1 or the interleukin-1 type 1 receptor. Interleukin-1beta, tumor necrosis factor-alpha and interferon-gamma expression were quantified using RT-PCR. Significant increases in interleukin-1beta and tumor necrosis factor-alpha mRNA were observed in the frontal cortex of azoxymethane-treated wild-type mice at coma stages of encephalopathy. Interferon-gamma, however, could not be detected in the brains of these animals. Onset of severe encephalopathy (coma) and brain edema in ALF mice were significantly delayed in interleukin-1 type 1 receptor or tumor necrosis factor receptor-1 knockout mice. Deletion of the interferon-gamma gene, on the other hand, had no significative effect on the neurological status or brain water content of acute liver failure mice. These results demonstrate that toxic liver injury resulting from exposure to azoxymethane is associated with selective induction of proinflammatory cytokines in the brain and that deletion of tumor necrosis factor receptor-1 or interlukin-1 type 1 receptor delays the onset of coma and brain edema in this model of acute liver failure. These findings further support a role for selective brain-derived cytokines in the pathogenesis of the cerebral complications in acute liver failure and suggest that anti-inflammatory strategies could be beneficial in their prevention.

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.

Single pass albumin dialysis (SPAD) in fulminant Wilsonian liver failure: a case report

Since fulminant Wilsonian liver failure has an extremely poor prognosis, the use of a liver support system that can bridge patients to liver transplant is life saving. We report here the case of a 17-year-old female who presented with fulminant Wilsonian liver failure and intravascular hemolysis. With the subsequent development of encephalopathy and oliguria, single pass albumin dialysis (SPAD) was initiated for 5 days to augment copper removal. Continuous venovenous hemodialysis (CVVHD) was performed using the PRISMA machine, with a blood flow of 100 ml/min and a dialysate flow of 2 L/h for 8 h, then 1 L/h. A 5% albumin dialysate was made by exchanging 1 L of 25% albumin for 1 L of Hemosol BO in a 5-L bag. Single pass albumin dialysis resulted in reductions in serum copper (154 to 59 microg/dL), conjugated bilirubin (37 to 23 mg/dL), lactate dehydrogenase (1305 to 729 units/L), and creatinine (1.1 to 0.9 mg/dL) as well as reduced blood transfusion requirements. Cessation of SPAD was followed by three plasmapheresis treatments for further copper removal. We conclude that SPAD is potentially an effective treatment in fulminant Wilson disease with hemolysis but that it should be used in combination with chelation to optimize the removal of copper.

New management options for end-stage chronic liver disease and acute liver failure: potential for pediatric patients

The management of children with end-stage chronic liver disease and acute liver failure mandates a multidisciplinary approach and intense monitoring. In recent years, considerable progress has been made in developing specific and supportive medical measures, but studies and publications have mainly concerned adult patients. Therapeutic approaches to complications of end-stage chronic liver disease and acute liver failure (e.g. refractory ascites, hepatorenal syndrome, encephalopathy, and cerebral edema) that may be applied to children are reviewed in this article.Mild-to-moderate ascites should be managed by modest salt restriction and oral diuretic therapy in the first instance. Large volume paracentesis associated with colloid volume expansion and diuretic therapy may be effective for acute relief. Treatment of hepatorenal syndrome type 1 with vasopressin analogs (terlipressin) is recommended prior to liver transplantation in order to improve renal function. Prevention and treatment of chronic hepatic encephalopathy are directed primarily at controlling the events that may precipitate hepatic encephalopathy and at reducing ammonia generation and increasing its detoxification or removal. In addition to reduction of gut ammonia production using non-absorbable disaccharides such as lactulose and/or antibacterials such as neomycin, sodium benzoate may be used on a long-term basis to prevent, stabilize, or improve hepatic encephalopathy. The management of hepatic encephalopathy in acute liver failure is considerably more unsatisfactory; treatment is aimed at preventing brain edema and intracranial hypertension. Extracorporeal liver support devices are now used commonly in critically ill children with acute renal failure, advanced hepatic encephalopathy, cerebral edema, intracranial hypertension, and severe coagulopathy. Continuous renal replacement therapy could potentially help support patients until liver transplantation is performed or liver regeneration occurs. The Molecular Adsorbent Recirculating System (MARS or albumin dialysis) is the liver support system most frequently used worldwide in adults and appears to offer distinct advantages over hepatocyte-based systems. There are no specific medical therapies or devices that can correct all of the functions of the liver. Apart from a few metabolic diseases presenting with severe liver dysfunction for which specific medical therapies may preclude the need for liver transplantation, liver transplantation still remains the only definitive therapy in most instances of end-stage chronic liver disease and acute liver failure. Future research should focus on gaining a better understanding of the mechanisms responsible for liver cell death and liver regeneration, as well as developments in hepatocyte transplantation and liver-directed gene therapy.

Successful liver transplantation and delivery in a woman with fulminant hepatic failure occurring during the second trimester of pregnancy

BACKGROUND

Severe liver dysfunction occurring during pregnancy is an unusual but dramatic event that poses special technical and ethical issues because it involves two lives.

METHODS AND RESULTS

We report the case of a 35-year-old woman with cryptogenic fulminant hepatic failure who underwent successful orthotopic liver transplantation at 22 weeks of pregnancy. After a relatively uneventful post-operative course she delivered a normal offspring at the 27th week of gestation. There were no obstetrical complications and neonatal outcome was excellent. After a year of follow-up, the patient is doing well,and the newborn has exhibited normal psychomotor and weight/height development.

CONCLUSION

This case illustrates the challenge of treating fulminant hepatic failure during pregnancy and demonstrates that liver transplantation is a feasible therapeutic option for treatment of patients with this condition, allowing successful completion of pregnancy.

Effect of albumin dialysis on intracranial pressure increase in pigs with acute liver failure: a randomized study

BACKGROUND

Increased intracranial pressure (ICP) worsens the outcome of acute liver failure (ALF). This study investigates the underlying pathophysiological mechanisms and evaluates the therapeutic effect of albumin dialysis in ALF with use of the Molecular Adsorbents Recirculating System without hemofiltration/dialysis (modified, M-MARS).

METHODS

Pigs were randomized into three groups: sham, ALF, and ALF + M-MARS. ALF was induced by hepatic devascularization (time = 0). M-MARS began at time = 2 and ended with the experiment at time = 6. ICP, arterial ammonia, brain water, cerebral blood flow (CBF), and plasma inflammatory markers were measured.

RESULTS

ICP and arterial ammonia increased significantly over 6 hrs in the ALF group, in comparison with the sham group. M-MARS attenuated (did not normalize) the increased ICP in the ALF group, whereas arterial ammonia was unaltered by M-MARS. Brain water in the frontal cortex (grey matter) and in the subcortical white matter at 6 hrs was significantly higher in the ALF group than in the sham group. M-MARS prevented a rise in water content, but only in white matter. CBF and inflammatory mediators remained unchanged in all groups.

CONCLUSION

The initial development of cerebral edema and increased ICP occurs independently of CBF changes in this noninflammatory model of ALF. Factor(s) other than or in addition to hyperammonemia are important, however, and may be more amenable to alteration by albumin dialysis.

Modification of continuous venovenous hemodiafiltration with single-pass albumin dialysate allows for removal of serum bilirubin

A 53-year-old woman was admitted to the hospital with ischemic colitis and underwent a subtotal colectomy. She developed acute renal failure, severe hyperbilirubinemia, and intense pruritus resistant to medical treatment. Extracorporeal albumin dialysis using a Molecular Adsorbent Recirculating System (MARS; Gambro Co, Lund, Sweden) has been used to treat liver failure and reduce total serum bilirubin (SB) levels. A trial of extracorporeal albumin dialysis with continuous renal replacement therapy (RRT) was instituted to achieve net removal of SB. A 25% albumin solution was mixed with conventional dialysate to yield a dialysate concentration of 1.85% or 5.0% albumin. The patient underwent 2 continuous RRT sessions using extracorporeal albumin dialysis (1.85% and 5.0% albumin dialysate). Pretreatment and posttreatment SB levels were determined, and total bilirubin concentration (TB) also was measured in each of the collection bags during conventional and albumin dialysis. Pretreatment and posttreatment SB levels were 50.4 mg/dL (862 micromol/L) and 39.0 mg/dL (667 micromol/L) with 1.85% albumin dialysate and 47.1 mg/dL (805 micromol/L) and 39.7 mg/dL (679 micromol/L) with 5.0% albumin dialysate, respectively. The collected dialysate TB level was 0.3 mg/dL (5 micromol/L) during nonalbumin RRT and increased to 1.37 +/- 0.06 mg/dL (23 +/- 1 micromol/L) with 1.85% albumin dialysis. The collected dialysate fluid TB level was 0.3 mg/dL (5 micromol/L) during the nonalbumin RRT and increased to 1.38 +/- 0.15 mg/dL (24 +/- 3 micromol/L) during 5.0% albumin RRT. Single-pass albumin dialysis with continuous RRT cleared SB better than standard continuous RRT. Single-pass albumin dialysis with continuous RRT is feasible and may be a viable alternative in centers that do not have access to MARS therapy. This modality merits additional evaluation for its efficacy in clearing albumin-bound serum toxins.

Cellular therapies for liver replacement

Insufficient donor organs for orthotopic liver transplantation worldwide have urgently increased the requirement for new therapies for acute and chronic liver disease. Whilst none are yet clinically proven there are at least two different approaches for which there is extensive experimental data, some human anecdotal evidence and some data emerging from Phase 1 clinical trials. Both approaches involve bio-engineering. In vivo tissue engineering involves isolated liver cell transplantation into the liver and/or other ectopic sites and in vitro tissue engineering, using an extracorporeal hepatic support system or bioartificial liver. Some questions are common to both these approaches, such as the best cell source and the therapeutic mass required, and are discussed. Others are specific to each approach. For cell transplantation in vivo the initial engraftment and repopulation will make a critical difference to the outcome, and development of markers for transplanted cells has enabled significant advances in understanding, and therefore manipulating, the process. Moreover, the role of immunosuppression is also important and novel approaches to natural immunosuppression are discussed. For use in a bioartificial liver, the ability for hepatocytes to perform ex vivo at in vivo levels is critical. Three dimensional culture improves cell performance over monolayer cultures. Alginate encapsulated cells offer a suitable 3-D environment for a bioartificial liver since they are both easily manipulatable and cryopreservable. The use of cells derived from stem cells or foetal rather than adult liver cells is also emerging as a potential human cell source which may overcome problems associated with xenogeneic cells.

MARS--does it stand the test of time?

Artificial liver support systems have been tested for decades in the management of liver failure. Generally, after some promising results published as case series, the device either disappears or fails to show significant benefit in controlled trials. Recently, the molecular absorbent recycling systems (MARS) or extracorporeal albumin dialysis (ECAD) technique appears to have broken this trend. Responding to the title one could summarize by saying this technique so far has stood the test of time. Data in support of its use in acute liver failure (ALF) is still scant and difficult to assess. However, in a well known but not very well defined entity of acute on chronic liver failure (AOCLF) the ECAD technique has been shown to improve survival compared to a similar randomized control group receiving standard supportive therapy. This well tolerated liver support system has real potential for widespread application if further well designed multicenter clinical trials continue to support its effectiveness. Its future lies probably in the management of the moribund hospitalized patient on the transplant list awaiting a donor liver.

Molecular adsorbents recirculating system dialysis for liver insufficiency and sepsis following right ventricular assist device after cardiac surgery

We report a case of right heart failure (RHF) and sepsis with liver insufficiency in a 70-year-old patient after coronary artery bypass graft surgery. Three hours after surgery the patient suddenly developed therapy refractory cardiac arrest caused by RHF. He had to have emergency surgery, under which the graft to the right coronary artery was revised and a right ventricular assist device was implanted. Heart function recovered and the assist device was explanted on day 1 after surgery. Thoracic closure was performed on day 5 after surgery. The patient went into septic shock on day 11. Liver dysfunction developed postoperatively and worsened the course of sepsis. Therefore, MARS (molecular adsorbents recirculating system) dialysis was performed once on day 20 after surgery. Liver function improved after MARS therapy and the patient recovered from sepsis. On day 46 the patient was transferred from the ICU of another hospital to one of the peripheral wards, to be finally discharged on day 67.

Equipment review: the molecular adsorbents recirculating system (MARS)

The molecular adsorbents recirculating system (MARS^®) is a form of artificial liver support that has the potential to remove substantial quantities of albumin-bound toxins that have been postulated to contribute to the pathogenesis of liver cell damage, haemodynamic instability and multi-organ failure in patients with acute liver failure (ALF) and acute-on-chronic liver failure (AoCLF). These toxins include fatty acids, bile acids, tryptophan, bilirubin, aromatic amino acids and nitric oxide. Data from controlled clinical trials are limited so far. One of two studies performed on small numbers of patients with AoCLF suggest a survival benefit, but no controlled data are available in the ALF setting. Our preliminary experience with MARS therapy, instituted late in the clinical course of five patients with severely impaired liver function, including three with AoCLF precipitated by sepsis and two with liver dysfunction due to sepsis in the absence of pre-existing chronic liver disease, indicates some clinical efficacy. However, the overall survival rate (1 of 5; 20%) remained poor. More data obtained from larger cohorts of patients enrolled in randomised controlled studies will be required in both the AoCLF and ALF settings to identify categories of liver failure patients who might benefit most from MARS treatment, to ascertain the most appropriate timing of intervention and to determine the overall impact on outcome, including cost-effectiveness.

In vitro comparison of the molecular adsorbent recirculation system (MARS) and single-pass albumin dialysis (SPAD)

The detoxification capacities of single-pass albumin dialysis (SPAD), the molecular adsorbents recirculation system, (MARS) and continuous veno-venous hemodiafiltration (CVVHDF) were compared in vitro. In each experiment 4,100 mL of toxin-loaded human plasma was processed for 6.5 hours. MARS treatment (n = 6) was undertaken in combination with CVVHDF. For SPAD (n = 6) and CVVHDF (n = 6) a high-flux hollow fiber hemodiafilter (identical to the MARS filter) was used. Levels of ammonia, urea, creatinine, bilirubin, and bile acids were determined. Concentrations before and after application of detoxification procedures were expressed as differences and were compared using the Kruskal-Wallis test. Post hoc comparisons for pairs of groups were adjusted according to Bonferroni-Holm. Time, group, and interaction effects were tested using the nonparametric ANOVA model for repeated measurements. SPAD and CVVHDF induced a significantly greater reduction of ammonia levels than MARS. No significant differences were found among SPAD, MARS, and CVVHDF with respect to other water-soluble substances. SPAD induced a significantly greater reduction in bilirubin levels than MARS. Reductions in bile acid levels were similar for SPAD and MARS. When operating MARS in continuous veno-venous hemodialysis mode, as recommended by the manufacturer, no significant differences in the removal of bilirubin, bile acids, urea, and creatinine were found. However, MARS in continuous veno-venous hemodialysis mode was significantly less efficient in removing ammonia than MARS in CVVHDF mode. In conclusion, the detoxification capacity of SPAD is similar to or even greater than that of MARS.

Albumin dialysis in cirrhosis with superimposed acute liver injury: possible impact of albumin dialysis on hospitalization costs

Albumin dialysis using the Molecular Adsorbents Recirculating System (MARS) has been found to be beneficial in the treatment of cirrhotic patients with acute decompensation to improve survival as well as reduce associated complications. The present study attempts to analyze the costs involved, and compare it to the benefit as a result of the MARS therapy, thus evaluating its cost-effectiveness. Using the results of a study by Kim et al. describing the effects of complications on the cost of hospitalization in alcoholic liver disease patients, the expenditure incurred in a group of 11 patients treated with standard medical therapy (five survivors) and a group of 12 patients treated with MARS in addition (11 survivors) (Heemann et al., Hepatology 2002) were analyzed. MARS resulted in a reduction of in-hospital deaths, as well as liver disease-related complications. Both these factors led to a substantial reduction of costs in the MARS group, which was enough to counterbalance the extra costs associated with extra-corporeal therapy. In the control group, the total hospitalization cost per survivor were calculated to be at $35,904. In the MARS group, the overall expenditure per survivor including standard medical therapy plus additional MARS liver support therapy were $32,036--a saving of nearly $4000 compared to the control group. Therefore, it appears that the benefits of MARS therapy are enough to justify the cost of treatment and safe hospital costs, at least in the described population. However, further studies are needed to confirm these results.

Extracorporeal albumin dialysis in patients with Amanita phalloides poisoning

BACKGROUND

Ingestion of Amanita phalloides is the most common cause of lethal mushroom poisoning. The relative late onset of symptoms is a distinct diagnostic feature of Amanita intoxication and also the main reason of failure for extracorporeal removal of Amanita-specific toxins from the gut and circulation.

PATIENTS AND METHODS

Extracorporeal albumin dialysis (ECAD) has been used on six consecutive patients admitted after A. phalloides poisoning with acute liver failure (ALF).

RESULTS

Six patients, with mean age of 46 years (range: 9-70 years), underwent one to three ECAD treatments. The mean time from mushroom ingestion until the first ECAD treatment was 76 h. Two patients regenerated spontaneously under ECAD treatment and orthotopic liver transplantation (OLT) could be avoided. Two patients were successfully bridged to OLT and one patient died because of cerebral herniation. One patient was treated with ECAD immediately after OLT because of the graft dysfunction and survived without re-transplantation.

CONCLUSION

ECAD appeared to be a successful treatment perspective in supporting liver regeneration or in sufficient bridging to OLT and also in treatment of graft dysfunction after OLT in patients with A. phalloides poisoning.

Liver support in fulminant liver failure after hemorrhagic shock

Acute liver failure (ALF) is a rare clinical syndrome associated with a mortality of up to 80% and its management remains an interdisciplinary challenge. Despite recent improvements in intensive care management, the mortality of patients with ALF remains high and is related to complications such as cerebral edema, sepsis and multiple organ failure. Emergency orthotopic liver transplantation (OLT) is currently the only effective treatment for those patients who are unlikely to recover spontaneously. Nevertheless, OLT is not always possible because of the shortage of the organs and/or complications related to ALF. Newly introduced liver-assist devices can temporarily support the patient's liver until native liver recovers or can serve as a bridging device until a liver graft is available. The support devices use both cell-based and non-cell-based techniques. One of the latest non-cell-based extracorporeal hepatic support devices, the molecular adsorbent recycling system (MARS), is based on the concept of albumin dialysis. MARS utilises selective hemodiafiltration with countercurrent albumin dialysis aiming to selectively remove both water-soluble and albumin-bound toxins of the low and middle molecular-weight range. We report on a young patient who presented with clinical symptoms of ischemic hepatitis and multi-organ failure (APACHE II score 38-->predicted postoperative mortality 87%) due to prolonged hemorrhagic shock. OLT was contraindicated because of history of pancreas cancer with metastases. It was necessary to use aggressive conservative therapy and an extracorporeal liver-assist device until liver regeneration began and hemodynamic conditions were stable. The patient underwent five treatments with MARS. During the treatment, there were improvements of hemodynamics, respiratory function, acid-base disturbances and laboratory parameters. The plasma disappearance rate of indocyanine green, a parameter of dynamic liver function, improved during MARS treatment. Although repeated neurological examination predicted diffuse brain damage (brain oedema, decreased cerebral blood flow), the patient recovered without any neurological deficits. The patient survived and was discharged from the hospital in good condition. In this case MARS treatment was successful in supporting the patient through the most critical period of ALF.

Review article: a medicine based on cell transplantation -- is there a future for treating liver diseases?

Cell-based therapies, comprising isolated hepatocyte transplantation, ex vivo gene therapy and bioartificial liver devices, may actually design a new scenario in the treatment of patients with liver failure. Recent advances in the liver repopulation field and the considerable excitement surrounding the use of haematopoietic stem cells for a 'regenerative medicine', allow us to see under a new light the alternative cell sources actually under investigation. In particular, the major drawbacks and the most important advantages of xenogenic primary cells, tumour-derived cell lines, immortalised hepatocytes and stem cells in the wide range of experimental and clinical applications are presented. Even if up to now none of them represent a 'gold standard' in the clinical practice, the intersecting advances in the development of mechanical components of artificial devices and in the liver biology and bioengineering will open tantalising possibilities to treat patients with liver failure, by tailoring the therapeutic choice on the basis of the aetiology and the stage of liver disease.