Improvement of hepatorenal syndrome with extracorporeal albumin dialysis MARS: results of a prospective, randomized, controlled clinical trial

Extracorporeal albumin dialysis

Previous studies reported that dialysis with albumin dialysate (AD) was effective in removing albumin-binding toxins (ABT), and the Molecular Adsorption Recycling System (MARS) and Continuous Albumin Purification System (CAPS) have been developed. These blood purification therapies were categorized into the concept of extracorporeal albumin dialysis (ECAD). ECAD is defined as extracorporeal therapies using AD for the removal of not only water-soluble but also ABT. It was reported that symmetric as well as asymmetric membrane dialyzers had the effect of the removal of bilirubin by AD. The larger pore size membrane can remove more bilirubin. In the greater albumin concentration in AD, the removal capacity for bilirubin by AD increased. Bilirubin in AD could be removed by a charcoal and a bilirubin adsorption column, and its concentration in AD remained approximately constant. In clinical performance of CAPS, cellulose triacetate membrane, 5% AD, bilirubin adsorber columns, and charcoal adsorber columns were used. This system was applied continuously for 24 h for treatment. CAPS could control not only renal but also liver function during the 24 h, without any adverse effect. MARS removes many toxic substances including ABT, and has beneficial effect on brain, liver, renal, and cardiovascular functions, and improvement of 30-day survival were reported. ECAD may become a possible therapeutic tool in patients with the disease state of ABT accumulation as an artificial kidney and liver. However, several attempts such as the application of recombinant human albumin and acetate free dialysate, should be required.

Which patients benefit from hemodialysis therapy in hepatorenal syndrome?

BACKGROUND AND AIM

Hepatorenal syndrome (HRS) occurs in patients with advanced liver cirrhosis and has a poor outcome. The aim of the present study was to investigate which patients with HRS are likely to benefit from hemodialysis.

METHODS

Data were collected prospectively from 30 patients with Child-Pugh C liver cirrhosis and HRS. Patients were either treated with continuous veno-venous hemodialysis (CVVHD) if they were mechanically ventilated, or with intermittent hemodialysis (HD) if they were not mechanically ventilated. Prognosis was assessed by the Child-Pugh and by the Model for End-Stage Liver Disease (MELD) score. The primary aim of the study was the analysis of overall and 30-day patient survival during hemodialysis therapy. To identify predictive factors of survival, variables obtained before the initiation of dialysis therapy were evaluated.

RESULTS

Patients' 30-day survival was 8/30 (median survival time 21 days). Among patients treated with mechanical ventilation, 30-day survival time was 0/15 while 8/15 patients without mechanical ventilation survived more than 30 days (P < 0.001). Using a multivariate model, the relative hazards for serum albumin, international normalized ratio (INR) and catecholamine therapy were not different from one another (P > 0.05), indicating that these parameters were not independent predictors of survival. Mechanical ventilation was an independent risk factor for 30-day (relative hazard 6.6 [1.6-27.7], P < 0.001) and overall survival (relative hazard 6.3 [1.5-26.5], P = 0.01). Child-Pugh (P < 0.01) and the MELD (P < 0.01) score were predictive for overall survival independent of mechanical ventilation.

CONCLUSIONS

Patients with HRS without mechanical ventilation may benefit from hemodialysis, whereas hemodialysis seems to be futile in patients with mechanical ventilation.

Thromboelastography used to assess coagulation during treatment with molecular adsorbent recirculating system

Coagulopathy is a life-threatening complication of liver cirrhosis. We describe the effect of molecular adsorbent recirculating system (MARS), a cell-free dialysis technique, on the blood coagulation of cirrhotic patients. From February 2002 to July 2002, nine patients--five males (55.5%) and four females (44.4%), age 47-70 yr (median 56)--underwent 12 courses (4-7 sessions each) of MARS. Patients were treated for the following indications: six (66.6%) acute-on-chronic hepatic failure, three (33.3%) intractable pruritus. Platelet count, prothrombin time (PT), international standardized ratio and thromboelastography were measured before and after each MARS session. Coagulation factors II, V, VII, VIII, IX, X, XI, XII, XIII, von Willebrand, lupus anticoagulant, protein C, protein S, antithrombin III, plasminogen, alpha 2 antiplasmin, D-dimer, fibrin monomers, complement, and C(1) inactivator were measured before and at the end of each MARS treatment. We found a statistically significant difference (p < 0.05) in the platelet count, PT, all the thromboelastograph variables (reaction and constant time, alpha angle, and maximal amplitude), factor VIII, von Willebrand, and D-dimer, when measured before and after MARS. Previous reports have shown amelioration of blood coagulation following MARS treatments. However, we document that MARS induces coagulopathy through a platelet-mediated mechanism, whereby platelet may be mechanically destroyed during the passage of blood through the filters and lines. An alternative postulated mechanism is an immune-mediated platelet disruption - coagulopathy.

First use of the Molecular Adsorbent Recirculating System technique on patients with hypoxic liver failure after cardiogenic shock

The Molecular Adsorbent Recirculating System (MARS) has been proven to prolong survival in patients with hepatorenal syndrome. MARS is a modified dialysis that uses an albumin containing dialysate, which is recirculated and perfused online through charcoal and anion exchanger columns. It allows the selective removal of albumin bound substances. Despite advances in medical therapy and technology, the prognosis of patients with cardiogenic shock remains poor. Mortality rates are as high as 80%, often because of persistent multiple organ failure. To determine whether patients with hypoxic liver failure after cardiogenic shock after cardiac surgery might benefit from MARS, we performed a prospective, randomized, controlled, single center study. The primary objective was to prove that MARS improves survival. This article is a report on the interim analysis of the first 27 patients included between August 2000 and December 2001; 14 patients were in the MARS group, and 13 patients were in the non-MARS group. All had bilirubin levels greater than 8 mg/ml. Both groups had a similar risk profile. The MARS group received MARS for 3 consecutive days-if bilirubin was still greater than 6 mg/dl afterward, MARS was continued. The non-MARS group received conventional therapy. We had seven survivors in the MARS group (50%) compared with four (32%; p = ns) in the non-MARS group. We conclude that despite the limited number of patients included in this analysis, MARS can be recommended for patients with acute, hypoxic liver failure because it might prolong survival. Further studies in similar patient cohorts are needed to verify our results.

Review article: pharmacological treatment of hepatorenal syndrome

Hepatorenal syndrome (HRS) is a common complication of advanced cirrhosis characterized not only by renal failure but also by marked alterations in systemic haemodynamics and activity of endogenous vasoactive systems. Renal failure is due to a severe vasoconstriction of the renal circulation. The pathogenesis of HRS is not completely understood but it is probably the result of extreme underfilling of the arterial circulation secondary to arterial vasodilation located in the splanchnic circulation. As well as the renal circulation, all other extrasplanchnic vascular beds appear to be vasoconstricted. The diagnosis of HRS is currently based on the exclusion of nonfunctional causes of renal failure; prognosis of patients with HRS is very poor. Liver transplantation is the best option in selected patients, but it is not always applicable as survival expectancy is short. Vasoconstrictor drugs with preferential effect on the splanchnic circulation (vasopressin analogues with a predominant V1 receptor effect, such as terlipressin--Glypressin) are very effective in improving renal function, with reversal of HRS being achieved in approximately two-thirds of patients. There is no agreement as to the terlipressin treatment regimen that is associated with a greater efficacy and lower incidence of side-effects. It appears that the administration of albumin together with terlipressin improves the therapeutic response rate. The impact of treatment on the natural course of HRS remains to be assessed in prospective investigations, but it seems that the reversal of HRS is associated with improved survival. Finally, treatment of patients with HRS with terlipressin before transplantation seems to improve post-transplantation outcome.

Review article: prognosis of hepatorenal syndrome--has it changed with current practice?

The Consensus Conference on Hepatorenal Syndrome (HRS) organized by the International Ascites Club in 1994 redefined HRS, introduced new diagnostic criteria that are now widely accepted, and proposed the distinction between two types of HRS: type 1 and type 2. Before the introduction of the new therapeutic options, the median survival of patients with type 1 HRS was only 1.7 weeks, and 6-12 months in patients with type 2 HRS. Liver transplantation (LT) was the first therapeutic option to change the prognosis of cirrhotic patients with HRS and 5-year survival after LT in patients with HRS is only slightly less than that of transplanted patients without HRS and markedly increased when compared to survival in nontransplanted patients with HRS. Nevertheless, a large proportion of patients die before LT is possible because of the poor prognosis of HRS and the prolonged waiting times in most transplant centres. Other therapeutic approaches were therefore developed to increase survival in patients with HRS. Vasoconstrictors and transjugular intrahepatic portosystemic shunt (TIPS) are the most promising. The administration of vasoconstrictors together with albumin has been shown to reverse type 1 HRS and even to completely normalize renal function in 60-70% of treated patients. To date, four studies assessing TIPS in the management of type 1 HRS have been reported and TIPS insertion was technically successful in all of them. Given the shortage of donors for LT, vasoconstrictor therapy and TIPS strategies may be considered as a bridge to LT in patients with type 1 HRS.

Complicaciones postoperatorias en el trasplante hepático. Relación con la mortalidad

BACKGROUND AND OBJECTIVE

Liver transplant is an effective procedure for fulminant hepatitis or chronic liver disease and offers an adequate quality of life. However, even though it is a consolidated treatment, patients can develop serious complications in the immediate postoperative course.

PATIENTS AND METHOD

Prospective observational study of 131 patients admitted in our intensive care unit after liver transplant surgery. We studied variables related with the development of complications and their relation to outcome.

RESULTS

Intensive care unit mortality was 11.5%. Median stay was 4 days. 90% of patients presented 2 or more complications. Hyperglycemia, thrombocytopenia and hypothermia were the most frequent complications but they were not related with mortality. Less frequent but related to outcome complications were acute renal failure (23.6% mortality vs. 1.3%; p < 0.01), ADRS (63.6% vs 6.7%; p < 0,01), low cardiac output (71.4% vs 4.3%; p < 0.01), > or = 2 vasoactive drugs (61.9% vs 1.8%; p < 0.01), encephalopathy (37.5% vs 9.8%; p < 0.05), pneumonia (80% vs 8%; p < 0.01) and hemorrhage (29.4% vs 8.8%; p < 0.05). Graph ischemia, coagulopathy, reperfusion syndrome and use of blood derivatives during surgery were factors related with the development of complications and mortality. Multivariate analysis showed a relationship with mortality and low cardiac output, number of vasoactive drugs and total time of graft ischemia.

CONCLUSIONS

Complications during the postoperative course of liver transplant are frequent but most of them have no effect on prognosis. The negative effect of severe complications should be limited by optimizing the hemodynamic support in these patients and minimizing ischemia of transplanted organs.

Molecular adsorbent recirculating system for acute and acute-on-chronic liver failure: a meta-analysis

Molecular adsorbent recirculating system (MARS) is an important option for patients with liver failure to give them additional time for recovery or to serve as a "bridge" to transplantation. However, its effect on survival for such patients is not well known. Our aim was to assess the treatment effects of MARS on patients with acute and acute-on-chronic liver failure. The outcomes measure evaluated was survival. We searched Medline (1966-2002) and EMBASE (1974-2002) using the terms liver failure, liver support systems, and MARS. Our search was extended to the Cochrane Controlled Trials Registry Database, published abstracts from 5 international conferences, Teraklin (the manufacturer of MARS), known contacts, and bibliographies from each full-published report. We included trials published in English and non-English languages. Eligible studies were randomized and nonrandomized controlled trials, which compared the treatment effects of MARS with standard medical treatment. Of the 206 articles screened, 4 randomized controlled trials including 67 patients were analyzed. Two nonrandomized trials with 61 patients were used for explorative analysis. The methodology, population, intervention, and outcomes of each selected trial were evaluated by duplicate independent review. Disagreements were resolved by consensus. In the primary meta-analysis, MARS treatment did not appear to reduce mortality significantly compared with standard medical treatment [relative risk (RR), 0.56; 95% confidence interval (CI), 0.28-1.14; P = .11]. Only 1 of the 4 randomized trials analyzed showed significant reduction in mortality. Sensitivity analysis of 3 peer-reviewed trials did not reduce mortality significantly with MARS treatment (RR, 0.72; 95% CI, 0.37-1.40; P = .33). Subgroup analysis of 2 trials for acute liver failure and another 2 trails for acute-on-chronic liver failure also did not reveal any benefit to survival with MARS treatment. In contrast, explorative analysis of 2 nonrandomized trials showed a significant survival benefit with MARS treatment (RR, 0.36; 95% CI, 0.17-0.76; P = .007). This was possibly related to bias in the selection of patients in the nonrandomized trials. In conclusion, MARS treatment had no significant survival benefit on patients with liver failure when compared with standard medical therapy. However, we found only a few trials with a small number of patients for the analysis, allowing for the possibility of false negative and erroneous conclusions. Well-conducted randomized trials are strongly recommended to define the role of MARS in the treatment of patients with liver failure.

Pathophysiological effects of albumin dialysis in acute-on-chronic liver failure: a randomized controlled study

The pathophysiological basis of acute-on-chronic liver failure (ACLF) is unclear but systemic inflammatory response is thought to be important. In patients with ACLF, the molecular adsorbents recirculating system (MARS) improves individual organ function, but the effect of MARS on the proposed mediators of systemic inflammatory response is unclear. The present study was designed to determine the effect of MARS on the cytokine profile, oxidative stress, nitric oxide, and ammonia. A total of 18 patients with alcohol-related ACLF due to inflammation-related precipitants were randomized to receive standard medical therapy (SMT) alone, or with MARS therapy over 7 days. Plasma cytokines, malondialdehyde (MDA), free radical production, nitrate / nitrite (NOx), and ammonia were measured. Encephalopathy improved significantly with MARS (P < .01), but not with SMT. Mean arterial pressure and renal function remained unchanged. No significant change of plasma cytokines and ammonia levels were observed in either group. Plasma MDA levels did not change either. There was a fall in NOx (P < .05) with MARS, but not with SMT. In conclusion, in inflammation-related ACLF patients, albumin dialysis using MARS results in improvement of encephalopathy, independent of changes of ammonia or cytokines, without improving blood pressure or renal function. These results should temper the liberal use of MARS until further data is available.

Review article: hepatorenal syndrome--how to assess response to treatment and nonpharmacological therapy

Hepatorenal syndrome (HRS) is a complex syndrome. In addition to severe reduction of renal function due to renal vasoconstriction, there is impairment in systemic haemodynamics, activation of the renin-angiotensin and sympathetic nervous systems and antidiuretic hormone, vasoconstriction of the brain, muscle and skin, and dilutional hyponatraemia. Treatment in patients with type 2 HRS, the most frequent form of HRS, is directed towards managing refractory ascites. Paracentesis is the treatment of choice. TIPS is also effective but is more expensive, is associated with higher incidence of hepatic encephalopathy, and does not increase survival. Although a rapidly progressive renal failure is the most characteristic manifestation of type 1 HRS, there is failure in other organs such as the liver and the brain. A decrease in cardiac output develops in these patients, associated with a decrease in cardiopulmonary pressures. Since type 1 HRS mainly occurs in patients with spontaneous bacterial peritonitis and massive release of cytokines within the peritoneal cavity, it may be considered as a special form of multiorgan failure of circulatory origin. Not surprisingly, the treatment of choice in type 1 HRS is the combination of vasoconstrictors to reduce arterial vasodilation and plasma volume expansion with albumin to increase cardiac preload. TIPS is also effective in these patients and the combination of pharmacological treatment followed by TIPS may be the most effective approach.

Clinical application of bioartificial liver support systems

OBJECTIVE

To review the present status of bioartificial liver (BAL) devices and their obtained clinical results.

BACKGROUND

Acute liver failure (ALF) is a disease with a high mortality. Standard therapy at present is liver transplantation. Liver transplantation is hampered by the increasing shortage of organ donors, resulting in high incidence of patients with ALF dying on the transplantation waiting list. Among a variety of liver assist therapies, BAL therapy is marked as the most promising solution to bridge ALF patients to liver transplantation or to liver regeneration, because several BAL systems showed significant survival improvement in animal ALF studies. Until today, clinical application of 11 different BAL systems has been reported.

METHODS

A literature review was performed using MEDLINE and additional library searches. Only BAL systems that have been used in a clinical trial were included in this review.

RESULTS

Eleven BAL systems found clinical application. Three systems were studied in a controlled trial, showing no significant survival benefits, in part due to the insufficient number of patients included. The other systems were studied in a phase I trial or during treatment of a single patient and all showed to be safe. Most BAL therapies resulted in improvement of clinical and biochemical parameters.

CONCLUSIONS

Bioartificial liver therapy for bridging patients with ALF to liver transplantation or liver regeneration is promising. Its clinical value awaits further improvement of BAL devices, replacement of hepatocytes of animal origin by human hepatocytes, and assessment in controlled clinical trials.

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.

Extracorporeal liver support: waiting for the deciding vote

Because acute liver cell failure is associated with an exceedingly high mortality, liver support has been proposed since the 1950s to improve patient outcome. Early devices, including hemodialysis, hemofiltration, exchange transfusion, plasmapheresis, hemoperfusion, plasma and cross-hemodialysis or cross-circulation, appeared inefficient. Meanwhile, documented results of extracorporeal liver perfusion (ECLP) suggested its superiority over conventional treatment. These devices were abandoned with the development of liver transplantation (LT), which allowed a better outcome and longer survival rate. In the present day, the fact that patients die while waiting for LT because of organ shortage led to a renewed interest in liver support as bridge to LT or regeneration. These devices can be classified according to the presence or lack of hepatocytes, whereas biologic devices refers to the presence of cells or other organic and biochemical component. The absence of individual success of early models led to the development of combined hepatocyte free devices, or artificial liver, which are based upon the hemodiabsorption principle (Biologic-DT) or on the "albumin bound toxin hypothesis" (Molecular Adsorbents Recirculating System) with encouraging results. Meanwhile, hepatocyte based bioartificial liver devices (BLD) were conceived for a global "metabolic support." BLD were developed with the use of human hepatoma cell line (C3A) or primary or cryopreserved porcine hepatocytes. Preliminary experience gave promising results bridging patients to LT. Based upon the same principle of global hepatocyte metabolic support, ECLP regained interest, particularly with the development of transgenic pigs. Several concerns were raised about these devices. Artificial livers lacked any metabolic synthetic activity, the use of human liver for ECLP seems hardly acceptable because of organ shortage, and the accepted use of borderline livers for transplantation is pending trials for the use of xenogenic livers. For BLD, the concerns were the low hepatocyte mass, the absence of accessory liver cells, and the potential risk of seeding tumor cells into patient with the use of human hepatoma cell line. The use of porcine hepatocytes (BLD or ECLP) raised physiologic and immunologic concerns and particularly the fear of a possible transfer of porcine viral material. Although recent studies clearly demonstrate clinical improvement of patients with the use of recently developed liver support devices, most of reported prospective, controlled, or randomized trials had a small number of patients. To give the deciding vote and avoid previous pitfalls, trials need to be developed with a larger number of patients based upon statistically significant models with the following characteristics: 1) comprehensive understanding of the acute liver cell failure mechanisms, 2) world wide classification of conditions that require liver support, and 3) a clear definition of treatment success pending patients to LT or recovery without transplantation. There has not yet been conclusive evidence to support the benefits of extracorporeal liver support. We are still waiting for the deciding vote.

Midodrine, octreotide, albumin, and TIPS in selected patients with cirrhosis and type 1 hepatorenal syndrome

Hepatorenal syndrome (HRS) is a functional renal disorder complicating decompensated cirrhosis. Treatments to date, except liver transplantation, have been able to improve but not normalize renal function. The aim of this study was to determine the efficacy of transjugular intrahepatic portosystemic stent shunt (TIPS) as a treatment for type 1 HRS in ascitic cirrhotic patients, following improvement in systemic hemodynamics with a combination of midodrine, octreotide, and albumin (medical treatment). Fourteen ascitic cirrhotic patients with type 1 HRS received medical therapy until their serum creatinine reached below 135 micromol/L for at least 3 days, followed by a TIPS if there were no contraindications. Patients were assessed before and after medical treatment, as well as at 1 week and 1, 3, 6, and 12 months post-TIPS with measurements of renal function, sodium handling, systemic hemodynamics, central blood volume, and hormonal markers. Medical therapy for 14 +/- 3 days improved renal function (serum creatinine: 233 +/- 29 micromol/L vs. 112 +/- 8 micromol/L, P =.001) and renal sodium excretion (5 +/- 2 mmol/d vs. 9 +/- 2 mmol/d, P =.002) in 10 of the 14 patients. TIPS insertion in five of the responders further improved renal function and sodium excretion, so that by 12 months post-TIPS, glomerular filtration rate (96 +/- 20 mL/min, P <.01 vs. pre-TIPS) and urinary sodium excretion (119 +/- 15 mmol/d, P <.01 vs. pre-TIPS) were normal, associated with normalization of plasma renin and aldosterone levels and elimination of ascites. In conclusion, TIPS is an effective treatment for type 1 HRS in suitable patients with cirrhosis and ascites, following the improvement of renal function with combination therapy of midodrine, octreotide, and albumin.

Extracorporeal albumin dialysis: a procedure for prolonged relief of intractable pruritus in patients with primary biliary cirrhosis

BACKGROUND AND AIMS

Pruritus is a distressing symptom in patients with primary biliary cirrhosis, and when uncontrollable it is an indication for liver transplantation. Since pruritus can result from unknown substances that accumulate systemically as a consequence of impaired biliary secretion, we have assessed whether a new extracorporeal albumin dialysis (ECAD) procedure, the molecular-adsorbing recirculating system-MARS, has any effect on pruritus of cholestasis.

METHODS

Four patients with primary biliary cirrhosis and resistant pruritus were treated with two 7-h ECAD sessions 1 day apart. Pruritus was recorded from 15 days before the first session, before and after each session, and during the follow-up using a visual analogue scale (VAS). Standard liver tests as well as serum bile acid levels were also measured.

RESULTS

There was a clear association between ECAD treatment and relief of itching, which promptly disappeared in two patients, or decreased markedly in the other two. One patient was free of pruritus for 18 months except for short periods with mild pruritus. The second patient experienced amelioration of itching, which almost disappeared completely and recurred mildly 4 months later. In the other two patients pruritus was alleviated markedly after ECAD but gradually recurred. These two patients were treated again 9 and 7 months later with favorable effects on pruritus. The scratching skin lesions improved or disappeared in parallel with the alleviation of itching. The albumin dialysis procedure did not result in liver test changes, except for circulating bile acids, which decreased in all the patients. No significant adverse effects were observed.

CONCLUSIONS

The ECAD procedure seems to be an effective alternative for the treatment of patients with pruritus of cholestasis who do not respond to other therapeutic methods.

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.

Economic evaluation and 1-year survival analysis of MARS in patients with alcoholic liver disease

Objective of this study was to determine 1-year survival, costs and cost-effectiveness of the artificial liver support system Molecular Adsorbent Recirculating System (MARS) in patients with acute-on-chronic liver failure (ACLF) and an underlying alcoholic liver disease. In a case-control study, 13 patients treated with MARS were compared to 23 controls of similar age, sex and severity of disease. Inpatient hospital costs data were extracted from patients' files and hospital's internal costing. Patients and treating GPs were contacted, thus determining resource use and survival 1-year after treatment. Mean 1-year survival time in MARS group was 261 days and 148 days in controls. Kaplan-Meier analysis shows advantages of MARS patients (Logrank: P=0.057). Direct medical costs per patient for initial hospital stay and 1-year follow-up from a payer's perspective were Euro 18,792 for MARS patients and Euro 9638 for controls. The costs per life-year gained are Euro 29,719 (time horizon 1 year). From a societal perspective, the numbers are higher (costs per life-year gained: Euro 79,075), mainly because of the fact that there is no regular reimbursement of MARS and therefore intervention costs were not calculated from payer's perspective. A trade-off between medical benefit and higher costs has to be made, but 1-year results suggest an acceptable cost-effectiveness of MARS. Prolonging the time horizon and including indirect costs, which will be done in future research, would probably improve cost-effectiveness.

MARS treatment in posthepatectomy liver failure

Posthepatectomy liver failure (PHLF) is a dramatic complication following extensive liver resection or liver resection in a compromised liver, leading to death in 80% of cases. Molecular Adsorbent Recirculating System (MARS) is able to extract water and protein bound toxins out of the blood in liver failure patients. This paper describes the initial experience in the Netherlands using the MARS liver assist device in five patients with PHLF. In all patients, improvement of biochemical parameters was observed during MARS treatment along with clinical improvement in three patients. One patient survived. No clear guidelines for MARS treatment and prognostic factors for outcome after MARS treatment with regard to this patient group are available. In this paper, a MARS treatment regimen for PHLF is suggested based on literature and our own experience.

Effects of treatment of hepatorenal syndrome before transplantation on posttransplantation outcome. A case-control study

BACKGROUND

Pretransplant renal function is the major determinant of survival after liver transplantation (LTx). Patients with hepatorenal syndrome (HRS) have a poor outcome after LTx compared with patients transplanted without HRS.

AIM

To analyze the impact of treatment of HRS before LTx on outcome after transplantation.

METHODS

The outcome of patients with HRS (n=9) treated with vasopressin analogues before LTx was compared with that of a contemporary control group of patients without HRS (n=27) matched by age, severity of liver failure, and type of immunosuppression.

RESULTS

Cases and controls were similar with respect to pretransplantation characteristics. Three-year survival probability was similar between the two groups (HRS-treated: 100% vs control: 83%, P=0.15). No significant differences were found between the two groups with respect to the incidence of impairment of renal function after LTx (HRS-treated: 22% vs control: 30%), severe infections (22 vs 33%), acute rejection (33 vs 41%), days in Intensive Care Unit (6+/-1 vs 8+/-1), days in hospital (27+/-4 vs 31+/-4), and transfusion requirements (11+/-3 vs 10+/-2 units).

CONCLUSIONS

Patients with HRS treated with vasopressin analogues before LTx have a posttransplantation outcome similar to that of patients transplanted with normal renal function. These results suggest that HRS should be treated before LTx.

Artificial and bioartificial support systems for liver failure

BACKGROUND

Artificial and bioartificial liver support systems may 'bridge' patients with acute or acute-on-chronic liver failure to liver transplantation or recovery.

OBJECTIVES

To evaluate beneficial and harmful effects of artificial and bioartificial support systems for acute and acute-on-chronic liver failure.

SEARCH STRATEGY

Trials were identified through The Cochrane Hepato-Biliary Group Controlled Trials Register (September 2002), The Cochrane Central Register of Controlled Trials on The Cochrane Library (Issue 3, 2002), MEDLINE (1966 - September 2002), EMBASE (1985 - September 2002), and The Chinese Biomedical Database (September 2002), manual searches of bibliographies and journals, authors of trials, and pharmaceutical companies.

SELECTION CRITERIA

Randomised clinical trials on artificial or bioartificial support systems for acute or acute on-chronic liver failure were included irrespective of blinding, publication status, or language. Non-randomised studies were included in explorative analyses.

DATA COLLECTION AND ANALYSIS

Data were extracted independently by three reviewers. Results were presented as relative risks (RR) with 95% confidence intervals (CI). Sources of heterogeneity were explored through sensitivity analyses and meta-regression. The primary outcome was mortality.

MAIN RESULTS

Twelve trials on artificial or bioartificial support systems versus standard medical therapy (483 patients) and two trials comparing different artificial support systems (105 patients) were included. Most trials had unclear methodological quality. Compared to standard medical therapy, support systems had no significant effect on mortality (RR 0.86; 95% CI 0.65-1.12) or bridging to liver transplantation (RR 0.87; 95% CI 0.73-1.05), but a significant beneficial effect on hepatic encephalopathy (RR 0.67; 95% CI 0.52-0.86). Meta-regression indicated that the effect of support systems depended on the type of liver failure (P = 0.03). In subgroup analyses, artificial support systems appeared to reduce mortality by 33% in acute-on-chronic liver failure (RR 0.67; 95% CI 0.51-0.90), but not in acute liver failure (RR 0.95; 95% CI 0.71-1.29). Two trials comparing artificial support systems showed significant mortality reductions with intermittent versus continuous haemofiltration (RR 0.58; 95% CI 0.36-0.94) and no significant difference between five versus ten hours of charcoal haemoperfusion (RR 1.03; 95% CI 0.65-1.62). The incidence of adverse events was inconsistently reported.

REVIEWER'S CONCLUSIONS

This Review indicates that artificial support systems may reduce mortality in acute-on-chronic liver failure. Artificial and bioartificial support systems did not appear to affect mortality in acute liver failure. However, considering the strength of the evidence additional randomised clinical trials are needed before any support system can be recommended for routine use.

Prometheus--a new extracorporeal system for the treatment of liver failure

BACKGROUND/AIMS

Extracorporeal detoxification systems for supportive therapy of liver failure have recently gained much interest. We herein report results from the first clinical application of Prometheus, a new liver support system in which albumin-bound substances are directly removed from blood by special adsorber. In a simultaneous step, high-flux hemodialysis is performed. We assessed safety, adsorber efficiency and clinical efficacy of the Prometheus system.

METHODS

Eleven patients with acute-on-chronic liver failure and accompanying renal failure were treated with Prometheus on 2 consecutive days for >4 h.

RESULTS

Prometheus treatment significantly improved serum levels of conjugated bilirubin, bile acids, ammonia, cholinesterase, creatinine, urea and blood pH. There were no significant changes in hemoglobin and platelet levels, whereas leucocytes increased without signs of systemic infection. No treatment-related complications except a blood pressure drop in two patients with systemic infection were noted. In one patient (Child-Pugh score: 15) Prometheus treatment could not be completed due to onset of uncontrolled bleeding 16 h after dialysis.

CONCLUSIONS

Prometheus is a safe supportive therapy for patients with liver failure. A significant improvement of the biochemical milieu was observed already after two treatments. Prospective controlled studies with the Prometheus system are necessary to evaluate hard clinical end-points.

Hepatorenal syndrome

Hepatorenal syndrome (HRS) is a common complication of advanced cirrhosis, characterised by renal failure and major disturbances in circulatory function. Renal failure is caused by intense vasoconstriction of the renal circulation. The syndrome is probably the final consequence of extreme underfilling of the arterial circulation secondary to arterial vasodilatation in the splanchnic vascular bed. As well as the renal circulation, most extrasplanchnic vascular beds are vasoconstricted. The diagnosis of HRS is currently based on the exclusion of other causes of renal failure. The prognosis is very poor, particularly when there is rapidly progressive renal failure (type 1). Liver transplantation is the best option in patients without contraindications to the procedure, but it is not always possible owing to the short survival expectancy. Therapies introduced during the past few years, such as vasoconstrictor drugs (vasopressin analogues, alpha-adrenergic agonists) or the transjugular intrahepatic portosystemic shunt, are effective in improving renal function. Nevertheless, liver transplantation should still be done in suitable patients even after improvement of renal function because the outcome of HRS is poor. Finally, recent findings suggest that the risk of developing HRS in the setting of spontaneous bacterial peritonitis may be reduced by the administration of albumin together with antibiotic therapy, and that of HRS occurring in severe alcoholic hepatitis can be lowered by administration of pentoxifylline. Although these findings need to be confirmed, these two strategies represent innovative approaches to lower the frequency of HRS in clinical practice.

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.

Bioartificial liver support devices: historical perspectives

Fulminant hepatic failure (FHF) is an important cause of death worldwide. Despite significant improvements in critical care therapy there has been little impact on survival with mortality rates approaching 80%. In many patients the cause of the liver failure is reversible and if short-term hepatic support is provided, the liver may regenerate. Survivors recover full liver function and a normal life expectancy. For many years the only curative treatment for this condition has been liver transplantation, subjecting many patients to replacement of a potentially self-regenerating organ, with the lifetime danger of immunosuppression and its attendant complications, such as malignancy. Because of the shortage of livers available for transplantation, many patients die before a transplant can be performed, or are too ill for operation by the time a liver becomes available. Many patients with hepatic failure do not qualify for liver transplantation because of concomitant infection, metastatic cancer, active alcoholism or concurrent medical problems. The survival of patients excluded from liver transplantation or those with potentially reversible acute hepatitis might be improved with temporary artificial liver support. With a view to this, bioartificial liver support devices have been developed which replace the synthetic, metabolic and detoxification functions of the liver. Some such devices have been evaluated in clinical trials. During the last decade, improvements in bioengineering techniques have been used to refine the membranes and hepatocyte attachment systems used in these devices, in the hope of improving function. The present article reviews the history of liver support systems, the attendant problems encountered, and summarizes the main systems that are currently under evaluation.

Hypoglycemia in nondiabetic patients undergoing albumin dialysis by molecular adsorbent recirculating system

It was observed that patients developed episodes of hypoglycemia during molecular adsorbent recycling system (MARS) treatment. The aim of this study is to assess the effect of MARS treatment on blood glucose concentration to formulate appropriate dextrose replacement guidelines during MARS dialysis. Five patients with liver failure each underwent a 6- to 8-hour MARS treatment. No patient had a history of diabetes or was administered insulin or oral antihyperglycemic agents throughout the period of albumin dialysis. There was no active intervention or restriction on glucose intake. Rather, a dextrose drip and boluses were allowed based on each patient's condition and the clinical judgment of the attending physician. Blood glucose concentration was monitored hourly during the period of MARS treatment. Glucose loss in dialysate fluid was quantified hourly by measuring the total volume of dialysate fluid and assaying the glucose concentration in dialysate fluid. Mean glucose removal during a 6-hour MARS session was 37.19 +/- 5.58 g. Mean glucose removal rate was 6.20 +/- 0.93 g/h. In addition to a maintenance drip supporting the caloric requirement of patients, a dextrose replacement drip that paralleled the rate of glucose removal would prevent patients from experiencing episodes of hypoglycemia during MARS treatment. Dextrose replacement at a mean rate of 6 g/h (range, 5 to 7 g/h) in patients without diabetes undergoing albumin dialysis by MARS is recommended.

Intensive care support therapy

Patients with small-for-size syndrome (SFSS) and acute liver failure share some important clinical features that are paralleled by common approaches to their intensive care unit management. Both are characterized by a period of acute hepatic insufficiency, with clinical features reflecting the impairment of metabolic and immunologic function that results. The basic principles of management of the two conditions remain essentially the same: to support hepatic regeneration, to anticipate and prevent the development of complications, and to identify patients unlikely to survive early in their clinical course so that retransplantation may be considered. Many treatments are available in the intensive care unit to overcome biochemical and metabolic disturbances in acute liver failure. Optimal pharmacologic management of SFSS complicated by portal hypertension and variceal hemorrhage is currently uncertain. Extracorporeal liver support has several theoretical attractions in the critically ill patient with SFSS, through its ability by removal of hepatotoxins to provide an environment more conducive to hepatic regeneration and recovery, or to support and bridge the patient to transplantation. The molecular adsorbent recycling system has been proposed to remove both water-soluble and protein-bound toxins. This system is particularly attractive in the treatment of SFSS, however, despite its current clinical application, there are presently limited published data to support its use.

Liver failure: basis of benefit of therapy with the molecular adsorbents recirculating system

Accumulation of albumin-bound toxins is known to occur in liver failure, and to variable extents is responsible for the associated end-organ dysfunctions (kidney, circulation, brain). The toxin-binding and scavenging functions of albumin are exploited in albumin dialysis for removal of these toxins. The extracorporeal liver support device known as molecular adsorbents recirculating system (MARS) is 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 few years have demonstrated proven reduction in hyperbilirubinaemia, along with an improvement in encephalopathy, systemic haemodynamics and renal function in liver failure patients, as well as apparent improvement in survival. The results of larger controlled clinical trials, as well as studies investigating the pathophysiological basis of its effect, are awaited.

Advances in alcoholic liver disease

Alcoholic liver disease (ALD) remains a major cause of morbidity and mortality worldwide. For example, the Veterans Administration Cooperative Studies reported that patients with cirrhosis and superimposed alcoholic hepatitis had a 4-year mortality of >60%. Interactions between acetaldehyde, reactive oxygen and nitrogen species, inflammatory mediators and genetic factors appear to play prominent roles in the development of ALD. The cornerstone of therapy for ALD is lifestyle modification, including drinking and smoking cessation and losing weight, if appropriate. Nutrition intervention has been shown to play a positive role on both an inpatient and outpatient basis. Corticosteroids are effective in selected patients with alcoholic hepatitis and pentoxifylline appears to be a promising anti-inflammatory therapy. Some complementary and alternative medicine agents, such as milk thistle and S-adenosylmethionine, may be effective in alcoholic cirrhosis. Treatment of the complications of ALD can improve quality of life and, in some cases, decrease short-term mortality.

TNF-alpha elimination with high cut-off haemofilters: a feasible clinical modality for septic patients?

BACKGROUND

Renal replacement therapies with high cut-off haemofilters are new approaches in the adjuvant therapy of sepsis. We analysed the cytokine elimination capacity of a newly developed polyflux high cut-off haemofilter. Different renal replacement therapies are compared and tested for their clinical feasibility.

METHODS

Blood from healthy volunteers (n=15) was incubated for 4 h with 1 mg of endotoxin and then circulated through a closed extracorporeal circuit. A newly developed polyflux haemofilter (P2SX) was used. Haemofiltration, haemodialysis and albumin dialysis were tested. IL-1ra (17 kDa), interleukin-6 (IL-6) (28 kDa), tumour necrosis factor alpha (TNF-alpha) (51 kDa), albumin (64 kDa), creatinkinase (CK) (80 kDa) and IgG (140 kDa) were measured in blood and filtrates prior to the initiation and after 5 min, 1, 2 and 4 h.

RESULTS

Haemofiltration was superior to haemodialysis in the clearance capacity of all substances when applied in the 1 l/h ultrafiltration mode. Increasing the ultrafiltration rate/dialysate flow from 1 to 3 l/h led to a significant increase in cytokine clearances (P<0.001). At 3 l/h the differences between haemofiltration and haemodialysis vanished and both techniques achieved comparable cytokine clearances. Median clearance values ranged between 25 and 54 ml/min for interleukin-1 receptor antagonist (IL-1ra), 23 and 42 ml/min for IL-6 and 15 and 28 ml/min for TNF-alpha. Albumin loss was highest in the haemofiltration group with albumin clearances ranging between 7 and 13 ml/min. Using diffusion instead of convection significantly reduced the loss of albumin (P<0.01 for 1 l/h, P<0.05 for 3 l/h). Albumin dialysis was able to completely inhibit albumin loss but cytokine clearance capacity was limited.

CONCLUSIONS

High cut-off haemofilters achieve high clearances for inflammatory IL-6 and TNF-alpha. Due to the high protein loss in haemofiltration, dialysis in combination with balanced protein substitution seems to be a suitable approach for clinical trials.

Bound solute dialysis

We used the thermodynamic principles governing bound solute dialysis, commonly referred to as "albumin dialysis" or "sorbent dialysis" and practiced clinically with the Molecular Adsorbent Recirculating System (MARS) and Biologic-DT approaches, respectively, to develop a comprehensive understanding of the process. Dimensionless parameters emerging from the thermodynamic analysis that govern bound solute dialysis are as follows: (1) lambda, the binding power of the solute binding moiety; (2) kappa, the dialyzer mass transfer/blood flow rate ratio; (3) alpha, the dialysate/blood flow rate ratio; (4) beta, the dialysate/blood binding moiety concentration ratio, and (5) psi, the solute/binding moiety concentration ratio in the blood. Results from a mathematical model of countercurrent bound solute dialysis for phi = 0.9 indicate that for a given binding moiety (fixed lambda), the most important parameter for achieving high removal rates is the dialyzer mass transfer ratio for free (unbound) solute. The results also show solute removal approaching an asymptote with increasing beta that is dependent on kappa and independent of alpha. More importantly, results indicate that once a dialysis membrane is chosen, solute removal is virtually independent of blood flow rate, dialysate flow rate, and amount of binding moiety in the dialysate, provided the amount is greater than approximately 90% of that required to reach the asymptote. Experimental observations over a range of blood flow rates (100-400 ml/ minute), dialysate flow rates (50-400 ml/minute), and dialysate/blood albumin concentration ratios (beta = 0-0.3) corroborate the model predictions and indicate that < 4 g/L albumin in the dialysate solution is required for effective bound solute dialysis. The experimental results also show evidence of enhanced mass transfer once the dialysis membrane pore structure surface saturates with albumin.

Extracorporal albumin dialysis (MARS) improves cholestasis and normalizes low apo A-I levels in a patient with benign recurrent intrahepatic cholestasis (BRIC)

The familial cholestatic diseases Benign Recurrent Intrahepatic Cholestasis (BRIC) and Progessive Familial Intrahepatic Cholestasis type 1 (PFIC1) are characterized by intermittent or permanently elevated plasma bile salt levels, therapy-resistant extreme pruritus and peculiar biochemical abnormalities including low apolipoprotein apo A-I. Previously, symptomatic improvement has been demonstrated in BRIC patients after extracorporal albumin dialysis (MARS). We hypothesized that MARS improves cholestasis, induces changes in the bile salt profile and normalizes apo A-I serum levels in BRIC. A 17-year-old-female patient with BRIC experienced an episode of cholestasis lasting for more than 6 months with extreme pruritus and diarrhoea not responding to standard therapy. During a period of five days the patient was treated 3 x 8 h with MARS. The procedures were well tolerated and resulted in reduction of plasma bile salts by 58%. The plasma bile salt profile changed into a more hydrophilic composition after MARS. Diarrhoea discontinued and the pruritus improved significantly from 9 to 4 on a subjective scale. These effects lasted 4 months until a relapse occurred. Low plasma apo A-I levels (0.52 g/l) normalized after MARS (0.98 g/l). The procedures were well tolerated. Fatigue was noted as the only transient side-effect. In conclusion, MARS may induce a long-term symptomatic improvement and decrease of cholestatic markers in BRIC. Further studies evaluating efficacy and mechanism of MARS in patients with BRIC are needed.

Experiences with MARS liver support therapy in liver failure: analysis of 176 patients of the International MARS Registry

Extracorporeal liver support using the MARS recently has shown remarkable results in several trials. This study aims to extend the basis for analyses by making available the worldwide data with help of an international registry. One hundred and seventy six patients were analysed, main indications are acute-on-chronic liver failure (56%), acute liver failure (22%), primary graft dysfunction (15%), liver failure post liver surgery (4%) and miscellaneous (3%). The predicted survival within the first group based on a mean MELD score of 30.4 pts. and a mean Child score of 12.6 pts. was quite limited. The data suggest an improved survival accompanied by significant improvements of hepatic encephalopathy, mean arterial pressure, serum bilirubin level, creatinine, urea, albumin, INR, ammonia and MELD score. The results are confirming observations of other trials before which have shown MARS therapy to be an effective and safe extracorporeal liver support in liver failure.

Albumin dialysis: single pass vs. recirculation (MARS)

The single pass albumin dialysis (SPAD) was reported to be an alternative to the Molecular Adsorbent Recirculating System (MARS) for the effective removal of protein bound substances in liver failure. Three SPAD experiments using different albumin concentrations and dialysate flow rates were performed. In each experiment, 1000 ml human donor plasma, spiked with 250 mg unconjugated bilirubin, 200 mg sulfobromophthalein (BSP) and 115 mg glycocholic acid (N-[3alpha,7alpha,12alpha-trihydroxy-24-oxycholan-24-yl]glycine) - a conjugated bile acid (BA), circulated in a closed loop with 150 ml/min and was dialysed against albumin solution. These substances are bound to the different binding sites of albumin and have different association constants. For the comparison, the standard MARS experiment was performed using the same plasma flow rate of 150 ml/min. Moreover, the clearances of bilirubin for MARS and SPAD during clinical treatments were calculated using own data and those reported by Seige, Kreymann, Jeschke, et al. in Transplant Proc 1999; 31: 1371-5. The concentrations of bilirubin, BSP and BA were measured in plasma and dialysate and for these substances clearances (Cl) were calculated. It is known that the elimination rate of bilirubin is not very high during albumin dialysis in comparison to other substances, like bile acids, due to the high association constant. An increase of albumin concentration or the flow rate improved the efficacy but also raised the costs substantially. In this study, we have shown that MARS is the more effective kind of albumin dialysis for the important substances like bile acids. By SPAD an improvement of efficacy can be reached only by dramatic increase of the costs. Also, the earlier experiments showed that MARS is safer because of the removal of the stabilizers, which are normally included in the commercial albumin solutions.

MARS procedure as a bridge to combined liver-kidney transplantation in severe chromium-copper acute intoxication: a paediatric case report

We describe a case of multi-organ failure (liver-kidney insufficiency and brain oedema) caused by accidental, acute intoxication with a chromium and copper-containing substance, as an example of the introduction of the new extracorporeal procedure MARS (molecular adsorbents recirculating system) in a girl 3.5 years old.

Application of Molecular Adsorbent Recirculating System in patients with severe liver failure after hepatic resection or transplantation: initial single-centre experiences

Acute liver failure after hepatic surgery is still plaqued with high mortality rate. Recently, a liver dialysis system (MARS) that allows detoxification of albumin-bound substances and may hereby support liver regeneration and patient's recovery has been developed. In the present study, we report our experiences with MARS dialysis in patients with liver failure after hepatic resection or transplantation. Between September 1999 and January 2001, five patients were treated with MARS (2-5 courses). Though beneficial effects such as improvement of encephalopathy and renal function as well as reduced bilirubin levels were recorded during MARS therapy, only one patient survived. Neither significant technical problems nor adverse effects occurred by using MARS dialysis. We conclude that in surgical patients, acute liver failure is usually part of a complicated clinical course affecting multipleorgan systems. Thus, it is difficult to determine the specific influence of MARS on patient's outcome. However, beneficial effects observed in our patients justify its continuous use and may stimulate further evaluation in controlled studies with surgical patients.

Modular extracorporeal life support for multiorgan failure patients

Adults receiving respiratory Extracorporeal Membrane Oxygenation (ECMO) have 66% survival. Nonsurvivors develop multisystem organ failure (MSOF). Once hepatic failure develops, death usually follows shortly. Serum bilirubin > 300 micromol/l predicted death with 87.8% sensitivity and 90.3% specificity in 41 adults who received ECMO in our institution during 1998 and 1999. No patients survive with a peak bilirubin > 400 micromol/l. The Molecular Adsorbent Recirculating System (MARS) is a cell-free extracorporeal liver support device; we hypothesized that using MARS in adult respiratory ECMO patients with a bilirubin >300 micromol/l could improve survival in MSOF. The MARS was used in five such patients aged 19-56 who developed liver failure secondary to a respiratory illness. Mean peak bilirubin was 529 micromol/l and the lowest peak bilirubin was 436 micromol/l. Patients received between 1 and 8 MARS treatments, mean reduction in serum bilirubin for each patient ranging between 30 and 162 micromol/l. Two of five patients survived (40%), survivors showing the greatest reduction in serum bilirubin in response to MARS. All patients would have been expected to die according to our previous experience. We believe that MARS may prove a useful therapy for patients with MSOF.

The Molecular Adsorbent Recirculating System in patients with severe liver failure: clinical results at the K.U. Leuven

BACKGROUND

The Molecular Adsorbent Recirculating System (MARS) is a novel extracorporeal technique for liver support. We report the clinical results in the first 13 patients with severe liver failure treated at our institution.

METHODS

Patients with acute or acute on chronic liver failure of various aetiologies were treated with varying numbers of MARS sessions of six hours duration.

RESULTS

Mean APACHE II score was 18. In general, patients with multiple organ failure faired poorly even with MARS treatment. Five patients (38%) survived the hospitalisation. Eight patients (62%) fulfilled criteria for UNOS type I or 2 A status. Two of these patients survived. Five patients had a UNOS 2B status and three survived. In proportion, patients with severe itch, patients with primary non-function and those where MARS was used as a bridge to transplantation seemed to profit most from the treatment. The median reduction in bilirubin concentrations after the treatment period was -28.2%. In survivors, the median reduction was -37.7% and in patients who died was -15.9%. The median encephalopathy score improved from 1.7 to 0.5.

CONCLUSION

The molecular adsorbent recycling system (MARS) might be lifesaving in patients with severe liver failure of different aetiologies.

Economic evaluation of MARS--preliminary results on survival and quality of life

OBJECTIVES

The short-term medical benefit of the liver dialysis system MARS in patients with severe acute liver disease has clearly been demonstrated. An economic analysis of MARS has not been presented previously. Objective of the study is to calculate the costs per life saved and life year gained and to measure health related quality of life in patients who survived acute liver failure. First results on survival and HRQL are presented here.

STUDY DESIGN

Cost effectiveness and cost utility analysis of MARS are performed. All patients since 1993 with chronic liver failure (Bilirubin > 300 micro mol/l) of the university hospital Rostock are included in the original sample (n = 141). Survival data are calculated. Surviving patients were contacted personally, thus quality of life data (EQ 5D and SF12) determined. Patients were compared in case control study design. In a later stage inpatient hospital costs, direct and indirect outpatients costs are included in the analysis.

PRELIMINARY RESULTS

MARS-Patients show a higher survival: Kaplan-Meier cumulative survival after 100 days: 0.59 after MARS, 0.39 without (P <0.05). There was no significant difference in health related quality of life (SF12 and EQ-D). Calculations of quality adjusted life years (QALYs) result in 0.116 QALYs gained by treatment of one patient with MARS in one year.

DISCUSSION

First preliminary results suggest that 1 year after therapy MARS seems to have a positive effect concerning survival rate, survival time and QALYs gained. Final results of cost-effectiveness and cost-utility analysis will soon be presented.