Rapid resolution of brain edema and improved cerebral perfusion pressure following the molecular adsorbent recycling system in acute liver failure patients

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.

Acute liver failure

Untreated acute liver failure (ALF) has a poor outcome and so rapid diagnosis and management is vital if the patient is to survive. ALF has such profound and widespread physiological consequences that whenever possible, patients with ALF should be managed in an intensive care unit. Management is to support the physiology and treat the underlying cause. Advice should be sought from a centre capable of performing liver transplantation. Should recovery seem unlikely, liver transplantation is a viable treatment option in some cases.

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.

Review article: the current management of acute liver failure

BACKGROUND

Acute liver failure is a devastating clinical syndrome with a persistently high mortality rate despite critical care advances. Orthotopic liver transplantation (OLT) is a life-saving treatment in selected cases, but effective use of this limited resource requires accurate prognostication because of surgical risks and the requirement for subsequent life-long immunosuppression.

AIM

To review the aetiology of acute liver failure, discuss the evidence behind critical care management strategies and examine potential treatment alternatives to OLT.

METHODS

Literature review using Ovid, PubMed and recent conference abstracts.

RESULTS

Paracetamol remains the most common aetiology of acute liver failure in developed countries, whereas acute viral aetiologies predominate elsewhere. Cerebral oedema is a major cause of death, and its prevention and prompt recognition are vital components of critical care support, which strives to provide multiorgan support and 'buy time' to permit either organ regeneration or psychological and physical assessment prior to acquisition of a donor organ. Artificial liver support systems do not improve mortality in acute liver failure, whilst most other interventions have limited evidence bases to support their use.

CONCLUSION

Acute liver failure remains a truly challenging condition to manage, and requires early recognition and transfer of patients to specialist centres providing intensive, multidisciplinary input and, in some cases, OLT.

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.

Albumin dialysis has a favorable effect on amino acid profile in hepatic encephalopathy

According to one popular theory, hepatic encephalopathy (HE) is partly caused by an imbalance in plasma amino acid levels. The Fischer's ratio between branched chain amino acids (BCAAs) and aromatic amino acids (AAAs) correlates with the degree of HE; the lower Fischer's ratio, the higher the grade of HE. Extra-corporeal liver support systems, like MARS(R)-albumin dialysis (Molecular Adsorbents Recirculating System), can improve HE. The MARS(R) system uses a hyperosmolar albumin circuit to remove both water-soluble and albumin-bound substances. Plasma levels of neuroactive amino acids were analyzed in 82 consecutive patients with life-threatening liver failure admitted to our ICU. All patients fulfilled our indications for MARS treatment and most also fulfilled the criteria for liver transplantation (LTx). In patients with acute liver failure (ALF), as compared to those with acute decompensation of chronic liver failure (AcOChr), levels of leucine and isoleucine were significantly higher before MARS(R) treatment. In all patients, before MARS(R) treatment the higher the grade of HE grade the lower was the Fischer's ratio and higher were the levels of inhibitory neuroactive amino acids. During MARS(R) treatments the Fischer's ratio increased, and the grade of HE decreased. The increase in Fischer's ratio was mainly due to the decrease in AAAs. The plasma levels of neuroactive amino acids, methionine, glutamine, glutamate, histidine and taurine decreased during MARS(R)-treatment. In this study MARS(R)-albumin dialysis had a favorable effect on the plasma amino acid profile of patients with HE.

Sorbent-based artificial liver devices: principles of operation, chemical effects and clinical results

Devices for support of patients with liver failure are of two types: bioartificial livers and artificial livers. Bioartificial livers include hepatocytes in bioreactors to provide both excretory and synthetic liver functions. Artificial livers use nonliving components to remove toxins of liver failure, supply nutrients and macromolecules. Current artificial liver devices use columns or suspensions of sorbents (including adsorbents and absorbents) to selectively remove toxins and regenerate dialysate, albumin-containing dialysate, plasma filtrate or plasma. This article reviews three artificial liver devices. Liver Dialysis uses a suspension of charcoal and cation exchangers to regenerate dialysate. MARS uses charcoal and an anion exchanger to regenerate dialysate with albumin. Prometheus uses neutral and anion exchange resins to regenerate a plasma filtrate containing albumin and small globulins. We review the operating principles, chemical effects, clinical effects and complications of use of each type of artificial liver. These devices clearly improve the clinical condition of patients with acute or acute-on-chronic liver failure. Further randomized outcome studies are necessary to prove clinical outcome benefit of the artificial liver support devices, and define what types of patients appear most amenable to therapy.

[Albumin dialysis in patients with acute exacerbation of chronic liver failure in an intensive care unit]

BACKGROUND AND OBJECTIVE

To describe our experience with albumin dialysis (Molecular Adsorbent Recirculating System [MARS]) in patients who are in an intensive care unit due to an acute exacerbation of chronic liver failure.

PATIENTS AND METHOD

From January 2004 to October 2005 10 patients, aged 40 to 65 years (mean age 58.8), were admitted due to acute exacerbation of chronic liver failure. All of them suffered from an encephalopathy and were candidates for a liver transplantation. One to six MARS sessions were applied. Clinical parameters were registered before and after each session.

RESULTS

Of the 10 patients treated, 9 survived and 1 died. Five out of the 9 survivors were successfully transplanted. In 2 patients (one of them was the deceased one) the grade of encephalopathy was > I (II and III respectively), and in both improved to grade I. In the other ones, the encephalopathy did not worsen. The serum bilirubin diminished from 39.2 to 28.2 mg/dl (p < 0.01). In the 3 patients with serum creatinin > 1.5 mg/dl, this parameter diminished from 2.6 to 1.5 mg/dl (p < 0.01). Two patients had thrombocytopaenia and haemorrhage, and in one of them the MARS treatment had to be interrupted. No hypotension was observed.

CONCLUSIONS

The reduction in the serum bilirrubin and creatinin, as well as the clinical improvement of the two patients with encephalopathy grade > I, make us to think that the MARS can be useful to patients with acute exacerbation of a chronic liver failure as a bridge to a liver transplantation.

The Molecular Adsorbent Recirculating System (MARS) in the intensive care unit: a rescue therapy for patients with hepatic failure

Treatment in the intensive care unit of patients with end-stage liver disease has been limited. Liver transplantation has been a major improvement in this and has become standard in the management of these patients. However, many patients die awaiting liver transplantation, mainly due to the scarcity of organ donors. Conventional hemodialysis techniques have little or no effect on liver detoxification and do not improve the prognosis of these patients. In patients with acute hepatic failure, the majority of endogenous toxins leading to organ failure and accumulating in the blood are bound to albumin; therefore, the concept of albumin dialysis is of major interest. To date, the most widely developed system has been the Molecular Adsorbent Recirculating System (MARS), which is based on the selective removal of albumin-bound toxins from the blood. MARS enables simultaneous liver and kidney detoxification, improving the patient's clinical condition. It is a major improvement in the management of patients with hepatic failure that could permit, when appropriately indicated, recovery from an acute episode and enhance the chances of survival while waiting for an available organ donor.

Review article: non-biological liver support in liver failure

Liver failure, whether acute or acute-on-chronic, remains an important cause of morbidity and mortality. The lack of liver detoxification, metabolic and regulatory functions of the liver leads to life-threatening complications, such as renal failure, altered immune response, hepatic coma and systemic haemodynamic dysfunction, eventually culminating in multiorgan failure. Current medical therapy involves the management of the precipitating event and treatment of complications until the liver eventually recovers, leaving us with no other treatment options than transplantation if these attempts fail. However, the shortage in cadaveric organs and other transplant-related problems, have prompted the need for alternative methods to provide liver support. As liver failure is often potentially reversible, considerable effort has been invested in the development of liver support systems. Currently, most of the experience is available for non-biological support systems. They represent the focus of this review, which aims to define the goals of liver support, to describe the design of the different existing devices and to analyse the available data to determine their current status in the management of patients with liver failure.

[Artificial liver support systems: update on albumin dialysis (MARS)]

Mortality among patients with liver insufficiency continues to be unacceptably high. The prognosis of patients with acute episodes of chronic liver insufficiency is almost as poor as that of patients with acute liver failure. Therefore, systems that support liver function, either until liver transplantation can be performed or until resolution of the situation before acute injury occurs, are essential. Albumin dialysis is a system of artificial liver support that allows detoxification of albumin-related and hydrosoluble substances, thus maintaining the patient's homeostasis. Current clinical experience of this therapy is still limited, although beneficial effects on clinical, laboratory and hemodynamic parameters have been demonstrated. Multicenter, controlled trials to evaluate the effect of this therapy on survival in distinct diseases are needed.

Liver support for fulminant hepatic failure: is it time to use the molecular adsorbents recycling system in children?

OBJECTIVE

To describe the main liver support devices used for fulminant hepatic failure (FHF) and to review data on the Molecular Adsorbents Recycling System (MARS) and assess its efficiency in children.

DATA SOURCE

Studies were identified through selected readings and a MEDLINE search from 1975 and 2004 using fulminant hepatic failure, acute liver failure, primary graft dysfunction, liver support, MARS, and extracorporeal liver assist device as key words.

STUDY SELECTION

All original studies, including case reports, relating to the use of the MARS or albumin dialysis system were included. Additional attention was put on prognosis criteria of FHF severity in children.

DATA EXTRACTION

Study design, numbers and diagnoses of patients, definite or bridging treatment, outcome measures, and complications were extracted and compiled. Results of individual trials were combined on the risk ratio scale.

DATA SYNTHESIS

Nine randomized trials including 354 patients were identified. However, liver support failed to significantly affect mortality when compared with standard medical therapy. Albumin dialysis, and particularly MARS, emerges as an easily applicable technique for temporary liver support. Some well-designed studies have characterized its efficiency in a few indications, such as in intractable pruritus in chronic liver disease, in acute or chronic liver diseases, and in decompensated cirrhosis with hepatorenal syndrome. In adults and children with FHF, anecdotal reports suggest that MARS may stabilize the patient. However, no randomized controlled study has validated its use in this indication. A randomized controlled study is ongoing in adults with FHF. Such a trial seems to be unfeasible in children for several methodologic reasons.

CONCLUSIONS

Although promising preliminary results suggest that MARS may have a significant position in the therapeutic arsenal for FHF, no sufficient data exist to justify its use in children. For as long as the results of the ongoing adult trial are not available, the indications of this expensive technique in children with FHF are limited.

Emerging indications for albumin dialysis

The accumulation of albumin-bound toxins in liver failure is believed to be responsible for the development of associated end-organ dysfunctions (kidney, circulation, brain). Albumin dialysis utilizes the scavenging functions of albumin for the removal of toxins. The Molecular Adsorbents Recirculating System (MARS) is one such extracorporeal liver support device where blood is dialyzed across an albumin-impregnated membrane against 20% albumin. Charcoal and anion exchange resin columns in the circuit cleanse and regenerate the albumin dialysate. Clinical studies in the last decade have demonstrated proven reduction in hyperbilirubinemia, along with an improvement in encephalopathy in liver failure patients, as well as apparent improvement in survival. Some studies have also reported improvement of systemic hemodynamics and renal function in these patients. Amelioration of intractable pruritus and treatment of toxicities with albumin-bound substances are some of the newer indications emerging. However, the specific underlying pathophysiological mechanisms are still not clear. Two other systems based on the removal of albumin-bound toxins, the Prometheus (using the principle of fractionated plasma separation and adsorption [FPSA]), and the single pass albumin dialysis (SPAD) are also currently under development but available clinical data are limited.

Value of albumin dialysis therapy in severe liver insufficiency

A blood purification system, molecular adsorbents re-circulating system (MARS), is based on the removal of both protein-bound and water-soluble substances and toxins in the liver. We treated a total of 88 patients within 2 years. Of these patients, 45 had acute liver failure (ALF), 31 had acute decompensation of chronic liver disease, eight had graft failure and four had miscellaneous conditions. Of the patients with ALF, 80% survived; in 23 patients their own liver recovered and 13 patients underwent successful transplantation. Only 23% of patients with acute-on-chronic liver failure survived. Most of them were not considered for transplantation due to their having liver failure from alcoholism and from not abstaining from drinking. MARS is a promising therapy for ALF, allowing the patient's own liver to recover or allowing enough time to find a liver graft. Best results were achieved in patients who had been intoxicated with a lethal dose of toxin. On the other hand, we did not observe much benefit in patients with severe acute-on-chronic liver failure (AcoChr) who did not undergo liver transplantation.

Pica-associated cerebral edema in an adult

Acute cerebral edema due to lead intoxication is an unusual presentation in an adult. Here we describe an adult with pica presenting with severe encephalopathy due to extremely high lead levels (>200 microg/dl) with marked cerebral edema and mild hyperammonemia. Rapid initiation of chelation therapy led to a reduction in serum lead and ammonia levels and a resolution of the cerebral edema and encephalopathy, suggesting a close relationship between lead toxicity and hepatic dysfunction.

[Acute liver failure. Current aspects of diagnosis and therapy]

Disturbances of some partial liver functions, such as synthesis, excretion, or biotransformation of xenobiotics, are important for prognosis and ultimate survival in patients presenting with multiple organ dysfunction on the intesive care unit (ICU). The incidence of liver dysfunction is underestimated when traditional "static" measures such as serum-transaminases or bilirubin as opposed to "dynamic" tests, such as clearance tests, are used to diagnose liver dysfunction. Similar to the central role of the failing liver in MODS, extrahepatic complications, such as hepatorenal syndrome and brain edema develop in acute or fulminant hepatic failure and determine the prognosis of the patient. This is reflected in the required presence of hepatic encephalopathy in addition to hyperbilirubinemia and coagulopathy for the diagnosis of acute liver failure. In addition to these clinical signs, dynamic tests, such as indocyanine green clearance, which is available at the bed-side, are useful for the monitoring of perfusion and global liver function. In addition to specific and causal therapeutic interventions, e.g. N-acetylcysteine for paracetamol poisoning or termination of pregnancy for the HELLP-syndrome, new therapeutic measures, e.g. terlipressin/albumin or albumin dialysis are likely to improve the poor prognosis of acute-on-chronic liver failure. Nevertheless, liver transplantation remains the treatment of choice for fulminant hepatic failure when the expected survival is <20%.

Acute liver failure

Acute liver failure is a rare and life-threatening clinical syndrome following severe hepatic injury. Depending on the rapidity of its development, two distinct complications contribute to a high mortality: in hyperacute liver failure, rapid development of massive hepatic necrosis and apoptosis gives rise to severe hyperammonemia, hepatic encephalopathy and life-threatening cerebral edema. The high risk of cerebral herniation requires early listing for emergency liver transplantation. Patients with hyperacute liver failure surviving the initial episode of cerebral edema have a substantial potential for hepatic recovery. If progressive hepatic failure develops more slowly, astrocytic osmoregulation prevents cerebral herniation in most instances. Unfortunately, these patients have a small potential of hepatic regeneration and transplantation should be performed before renal failure, sepsis or multiorgan failure emerge. Experimental treatment methods including detoxification by artificial or bioartificial liver support or by stimulating hepatic regeneration are currently evaluated. Recognition of ammonia toxicity has stimulated the search for early ammonia-lowering strategies and strongly renewed the interest in dialytic therapies. Anti-apoptotic interventions are among the most promising pharmacological options for the near future.

A 3-year experience with Molecular Adsorbent Recirculating System (MARS): our results on 63 patients with hepatic failure and color Doppler US evaluation of cerebral perfusion

In our 3-year experience, we treated 63 patients with Molecular Adsorbent Recirculating System (MARS). The patients were divided as follows: 10 primary non-function (PNF) 16%, 10 delayed non-function (DNF) 16%, 16 Fulminant hepatitis (FH) 24%, 23 acute decompensation of chronic liver disease (ACLF) 38%, and 4 hepatic resection 6%. All patients who underwent MARS treatment had bilirubin >15 mg/dL, Glasgow Coma Score between 9 and 11, ammonium >160 microg/dL and non-coagulability. The determining factors taken into consideration for the continuation of MARS treatment were: an improvement in Glasgow Coma Score, and a decrease in ammonium and bilirubin. We also monitored hemodynamic parameters, acid-base equilibrium, and blood gas analysis before and after each treatment. In order to determine patients' neurological conditions, we not only took into account the Glasgow Coma Score, which does not give mathematically precise results but also took into account the fact that patients with hepatic coma had lower cerebral mean velocity in the cerebral arteries than patients without encephalopathy. For this reason, in the last 22 patients we monitored cerebral perfusion, determined by mean flow velocity (Vmean) in the middle cerebral artery. Our results were expressed as mean +/- SD and we analyzed the differences between mean values for each variable, before and after treatment by means of Student's t-test. At the end of treatment, we obtained significant P-values for bilirubin, ammonium, Glasgow Coma Score and creatinine. In 16/20 patients, we could demonstrate a clear correlation between the improvement in clinical conditions (especially neurological status) and improvement in cerebral perfusion, measured by color Doppler US.

Experience with albumin dialysis in five patients with severe overdoses of paracetamol

Five patients in whom the serum paracetamol levels or the amount of ingested paracetamol was high enough to cause severe liver injury were treated with N-acetyl-cysteine (NAC) and a molecular absorbant recirculating system (MARS). MARS treatment was started as early as possible in order to prevent or retard the development of hepatocyte necrosis. Four of our five patients survived without liver transplantation, and one died due to brain oedema. The early commencement with NAC and MARS treatments in paracetamol intoxication might give enough time for the liver to regenerate and thus avoid liver transplantation.

Extracorporeal liver support by recirculating albumin dialysis: analysing the effect of the first clinically used generation of the MARSystem

Albumin dialysis with the MARSystem is used in many hospitals to support excretory hepatic function in acute or acute on chronic liver failure. Potential pathogenic albumin bound substances accumulated in excretory liver insufficiency can be removed from patients blood by dialysis against albumin solution. A specific membrane enables the selective transport of albumin bound metabolites to the albumin containing dialysate compartment, where the loaded transport albumin is cleared and regenerated at the same time by adsorption columns and a second dialyser. Between 1993 and 1995 different membranes, set-ups and components in albumin dialysis were tested and led finally to the recirculating MARSystem with a modified polysulphone based membrane (P3/5S Gambro, Hechingen) and two adsorption columns (N350 and BR 350, ASAHI Medical Ltd.), which showed the best performance at this time. This first generation of MARSystems was used clinically between 1995 and 1998 with only minor changes in 15 patients with acute (n = 1) or acute deterioration of chronic liver disease in our department until the improved next generation of MARSystems has been available (MARS set and monitor, Teraklin AG, Rostock, Germany). Changes in blood tests pre/post during 95 single MARS treatments and in clinical status over treatment period were evaluated retrospectively.

RESULTS

A significant decrease of albumin bound substances (average reduction during single MARS treatments: bilirubin -18%, bile acids -43.7%) as well as of water soluble metabolites (creatinine -32%, urea -31%) was observed. During extracorporeal therapy also a significant drop in platelets (- 15.4%) and a prolongation of activated prothrombin time (- 21%) was documented, whereas haemoglobin, WBC, electrolytes as well as transaminases and albumin were not affected significantly.

CONCLUSION

Albumin dialysis with the first generation of MARS enables the removal of albumin bound and water soluble toxins. Unwanted side-effects and changes in laboratory tests are comparable to conventional haemodialysis (drop of platelets and prolongation of coagulation tests). The elimination of albumin bound and water soluble substances was accompanied by an improvement of clinical status.

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

In recent years different artificial liver support systems are being developed for use in patients with acute decompensation of chronic liver disease or acute liver failure. The molecular adsorbents recirculating system (MARS), a device in which patient's blood is dialysed across an albumin-impregnated membrane against a recirculated albumin-containing solution, seems to be effective in removing albumin-bound toxins, such as fatty acids, bile acids and bilirubin. Although the clinical experience with MARS is scarce, some pilot studies have reported its effectiveness at improving liver function and hepatic encephalopathy in patients with acute decompensation of chronic liver disease, and renal function in patients with hepatorenal syndrome type I. Data regarding MARS experience in acute liver failure and in primary graft dysfunction are encouraging but limited. Its real usefulness in these settings is, at present, under evaluation in randomized controlled clinical trials.

Extracorporeal treatment in fulminant hepatic failure: pathophysiologic considerations

Fulminant hepatic failure is a life-threatening clinical syndrome following severe hepatic injury leading to cerebral edema and brainstem herniation. Excessive mortality can be currently reduced only by timely orthotopic liver transplantation. Due to the shortage of donor organs, a considerable proportion of patients develop irreversible neurological damage, multiorgan failure or death while waiting for transplantation. Consequently, alternatives to orthotopic liver transplantation and methods of stabilizing patients on the waiting list including extracorporeal detoxification treatment are currently investigated. Recent advances in the pathophysiology of cerebral edema have challenged some of the traditional assumptions on which many blood detoxification systems are based. This article aims to integrate pathophysiology of hepatic encephalopathy and cerebral edema into a proposed future concept of liver support.