MARS and Prometheus: Our Clinical Experience in Acute Chronic Liver Failure

HEP-Net opinion on the management of ascites and its complications in the setting of decompensated cirrhosis in the resource constrained environment of Pakistan

Approximately one half of patients develop ascites within 10 years of diagnosis of compensated cirrhosis. It is a poor prognostic indicator, with only 50% surviving beyond two years. Mortality worsens significantly to 20% to 50% at one year if the ascites becomes refractory to medical therapy. Pakistan has one of the highest prevalence of viral hepatitis in the world and patients with ascites secondary to liver cirrhosis make a major percentage of both inpatient and outpatient burden. Studies indicate that over 80% of patients admitted with ascites have liver cirrhosis as the cause. This expert opinion suggests proper assessment of patients with ascites in the presence of underlying cirrhosis. This expert opinion includes appropriate diagnosis and management of uncomplicated ascites, refractory ascites and complicated ascites (including spontaneous bacterial peritonitis (SBP) ascites, hepatorenal syndrome (HRS) and hyponatremia. The purpose behind this expert opinion is to help consultants, postgraduate trainees, medical officers and primary care physicians optimally manage their patients with cirrhosis and ascites in a resource constrained setting as is often encountered in a developing country like Pakistan.

Liver depurative techniques: a single liver transplantation center experience

BACKGROUND

In a liver transplant (LT) center, treatments with Prometheus were evaluated. The main outcome considered was 1 and 6 months survival.

METHODS

During the study period, 74 patients underwent treatment with Prometheus; 64 were enrolled, with a mean age of 51 ± 13 years; 47 men underwent 212 treatments (mean, 3.02 per patient). The parameters evaluated were age, sex, laboratorial (liver enzymes, ammonia) and clinical (model for end-stage liver disease and Child-Turcotte-Pugh score) data.

RESULTS

Death was verified in 23 patients (35.9%) during the hospitalization period, 20 patients (31.3%) were submitted to liver transplantation, and 21 were discharged. LT was performed in 4 patients with acute liver failure (ALF, 23.7%), in 7 patients with acute on chronic liver failure (AoCLF, 43.7%), and in 6 patients with liver disease after LT (30%). Seven patients who underwent LT died (35%). In the multivariate analysis, older age (P = .015), higher international normalized ratio (INR) (P = .019), and acute liver failure (P = .039) were independently associated with an adverse 1-month clinical outcome. On the other hand, older age (P = .011) and acute kidney injury (P = .031) at presentation were both related to worse 6-month outcome. For patients with ALF and AoCLF we did not observe the same differences.

CONCLUSIONS

In this cohort, older age was the most important parameter defining 1- and 6-month survival, although higher INR and presence of ALF were important for 1-month survival and AKI for 6-month survival. No difference was observed between patients who underwent LT or did not have LT.

Liver dialysis in acute-on-chronic liver failure: current and future perspectives

Patients with acute-on-chronic liver failure (ACLF) are known to have a very high mortality rate as the majority of these patients succumb to multiorgan failure. Liver transplant remains the only option for these patients; however, there are problems with its availability, cost and also the complications and side effects associated with immunosuppression. Unlike advanced decompensated liver disease, there is a potential for hepatic regeneration and recovery in patients with ACLF. A liver support system, cell or non-cell based, logically is likely to provide temporary functional support until the donor liver becomes available or the failing liver survives the onslaught of the acute insult and spontaneously regenerates. Understanding the pathogenesis of liver failure and regeneration is essential to define the needs for a support system. Removal of hepatotoxic metabolites and inhibitors of hepatic regeneration by liver dialysis, a non-cell-based hepatic support, could help to provide a suitable microenvironment and support the failing liver. The current systems, i.e., MARS and Prometheus, have failed to show survival benefits in patients with ACLF based on which newer devices with improved functionality are currently under development. However, larger randomized trials are needed to prove whether these devices can enable restoration of the complex dysregulated immune system and impact organ failure and mortality in these patients.

Modifying three-dimensional scaffolds from novel nanocomposite materials using dissolvable porogen particles for use in liver tissue engineering

Background:

Although hepatocytes have a remarkable regenerative power, the rapidity of acute liver failure makes liver transplantation the only definitive treatment. Attempts to incorporate engineered three-dimensional liver tissue in bioartificial liver devices or in implantable tissue constructs, to treat or bridge patients to self-recovery, were met with many challenges, amongst which is to find suitable polymeric matrices. We studied the feasibility of utilising nanocomposite polymers in three-dimensional scaffolds for hepatocytes.

Materials and methods:

Hepatocytes (HepG2) were seeded on a flat sheet and in three-dimensional scaffolds made of a nanocomposite polymer (Polyhedral Oligomeric Silsesquioxane [POSS]-modified polycaprolactone urea urethane) alone as well as with porogen particles, i.e. glucose, sodium bicarbonate and sodium chloride. The scaffold architecture, cell attachment and morphology were studied with scanning electron microscopy, and we assessed cell viability and functionality.

Results:

Cell attachment to the scaffolds was demonstrated. The scaffold made with glucose particles as porogen showed a narrower range of pore size with higher porosity and better inter-pore communications and seemed to encourage near normal cell morphology. There was a steady increase of albumin secretion throughout the experiment while the control (monolayer cell culture) showed a steep decrease after day 7. At the end of the experiment, there was no significant difference in viability and functionality between the scaffolds and the control.

Conclusion:

In this initial study, porogen particles were used to modify the scaffolds produced from the novel polymer. Although there was no significance against the control in functionality and viability, the demonstrable attachment on scanning electron microscopy suggest potential roles for this polymer and in particular for scaffolds made with glucose particles in liver tissue engineering.

Acute-on-chronic liver failure: concept, natural history, and prognosis

PURPOSE OF REVIEW

A population of patients with previously compensated cirrhosis will develop acute deterioration resulting in multiorgan failure and high short-term mortality. Complications of cirrhosis frequently culminate in admissions to the ICU. This review advances the concept of acute-on-chronic liver failure as a distinct clinical entity.

RECENT FINDINGS

Recently, the American Association for the Study of Liver Disease and the European Association for the Study of the Liver created a research consortium to advance the state of the science of acute-on-chronic liver failure. The goal of this consortium is aimed at improving outcomes, identification of a subset of patients with cirrhosis at high risk for deterioration, and the inciting events that lead to this deterioration. Liver transplant remains the only curative option for advanced cirrhosis; however, the limited number of available organs necessitates innovations in the care of advanced liver disease. Liver replacement therapies have not as yet demonstrated reduction in mortality, but have demonstrated improvements in other measures. Large-scale prospective studies of cirrhosis are required.

SUMMARY

Acute-on-chronic liver failure may be a distinct clinical entity with a potential for reversibility when identified early and managed with aggressive critical care support.

Multicenter study of plasma diafiltration in patients with acute liver failure

Plasma diafiltration (PDF) is a blood purification therapy in which simple plasma exchange (PE) is performed using a selective membrane plasma separator while the dialysate flows outside the hollow fibers. A prospective, multicenter study was undertaken to evaluate the changes in bilirubin, IL-18, and cystatin C, as well as the 28-day and 90-day survival rates, with the use of PDF according to the level of severity as measured by the Model for End-Stage Liver Disease (MELD) score. Twenty-one patients with liver failure were studied: 10 patients had fulminant hepatitis and PDF therapies were performed 28 times; 11 had acute liver failure with the therapy performed 96 times. Levels of total bilirubin, IL-18, and cystatin C decreased significantly after treatment. The 28-day survival rate was 70.0% and that at 90 days was 16.7%. According to the severity of the MELD score, each of the results compared well with the use of Molecular Adsorbent Recirculating System or Prometheus therapy. In conclusion, PDF appears to be one of the most useful blood purification therapies for use in cases of acute liver failure in terms of medical economics and the removal of water-soluble and albumin-bound toxins.

The treatment of acute liver failure with fractionated plasma separation and adsorption system: Experience in 85 applications

INTRODUCTION

Artificial liver support systems represent a potential useful option for the treatment of liver failure. The outcomes of patients treated with the fractionated plasma separation and adsorption (FPSA) system are presented.

PATIENTS AND METHODS

FPSA was performed 85 times for 27 patients (median 3 treatments/patient) with liver failure [85.2% acute liver failure (ALF) and 14.8% acute-on-chronic liver failure] using the Prometheus 4008H (Fresenius Medical Care) unit. Citrate was used for anticoagulation. A variety of clinical and biochemical parameters were assessed. Comparisons between pretreatment and post-treatment data were performed using paired t-test.

RESULTS

The 85 sessions had a mean duration of 6 h. There were significant decreases in total bilirubin (13.18 +/- 9.46 mg/dL vs. 9.76 +/- 7.05 mg/dL; P < 0.0001), ammonia (167.6 +/- 75 mg/dL vs. 120 +/- 43.8 mg/dL; P < 0.0001), blood urea nitrogen (BUN; 12.55 +/- 13.03 mg/dL vs. 8.18 +/- 8.15 mg/dL; P < 0.0001), creatinine (0.54 +/- 0.47 mg/dL vs. 0.46 +/- 0.37 mg/dL; P = 0.0022) levels, and in pH (7.48 +/- 0.05 vs. 7.44 +/- 0.08; P = 0.0045). Four patients (14.8%) received liver transplantation after the treatments; in nine patients, transplantation was not necessary anymore (33%); the remaining 14 patients did not receive a transplantation because they were either not appropriate candidates or no organ was available. Overall survival was 48.1% (4 transplanted and 9 treated patients). No hematological complications related to FPSA were observed.

CONCLUSIONS

FPSA system is a safe and effective detoxification method for patients with liver dysfunction, including ALF. The system is useful as a symptomatic treatment before liver transplantation; in up to 1/3 of the cases, it can even be used as a sole method of treatment.

An Official ATS/ERS/ESICM/SCCM/SRLF Statement: Prevention and Management of Acute Renal Failure in the ICU Patient: an international consensus conference in intensive care medicine

OBJECTIVES

To address the issues of Prevention and Management of Acute Renal Failure in the ICU Patient, using the format of an International Consensus Conference.

METHODS AND QUESTIONS

Five main questions formulated by scientific advisors were addressed by experts during a 2-day symposium and a Jury summarized the available evidence: (1) Identification and definition of acute kidney insufficiency (AKI), this terminology being selected by the Jury; (2) Prevention of AKI during routine ICU Care; (3) Prevention in specific diseases, including liver failure, lung Injury, cardiac surgery, tumor lysis syndrome, rhabdomyolysis and elevated intraabdominal pressure; (4) Management of AKI, including nutrition, anticoagulation, and dialysate composition; (5) Impact of renal replacement therapy on mortality and recovery.

RESULTS AND CONCLUSIONS

The Jury recommended the use of newly described definitions. AKI significantly contributes to the morbidity and mortality of critically ill patients, and adequate volume repletion is of major importance for its prevention, though correction of fluid deficit will not always prevent renal failure. Fluid resuscitation with crystalloids is effective and safe, and hyperoncotic solutions are not recommended because of their renal risk. Renal replacement therapy is a life-sustaining intervention that can provide a bridge to renal recovery; no method has proven to be superior, but careful management is essential for improving outcome.

[Evaluation of extracorporeal liver support systems in the treatment of liver failure. A systematic review]

OBJECTIVE

To evaluate the safety and efficacy of the MARS and Prometheus extracorporeal liver support systems in the treatment of liver failure.

DESIGN

We performed a systematic review of the literature from January 1999 to June 2009 in the Medline, Embase, HTA, DARE, NHSEED, Cochrane Library Plus, Clinical Trials Registry and HSRPROJ databases. Study selection was based on a series of previously established inclusion criteria related to the study design, population, type of intervention, language, and outcome measures.

PATIENTS AND INTERVENTIONS

Patients with acute liver failure or acute exacerbations of chronic liver failure treated with the MARS or Prometheus systems.

OUTCOME MEASURES

Data on safety, long-term survival, clinical effects and biochemical and hemodynamic variables.

RESULTS

We selected 22 studies evaluating the safety and efficacy of the MARS and Prometheus systems. Adequate evaluation of these techniques was hampered by the heterogeneity of the studies and their methodological limitations.

CONCLUSIONS

Extracorporeal liver support systems are able to purify both hydrosoluble and protein-bound substances. However, current data show that only the MARS system reduces mortality in acute liver failure and in acute exacerbations of chronic liver failure, although this reduction is non-significant. These techniques can be considered safe, with adverse effects similar to those of the control group. Their main indication is severe liver failure, for short periods while the liver recovers or a liver transplant becomes available.

Results of treatment of acute liver failure patients with use of the prometheus FPSA system

OBJECTIVE

Herein we have presented the results of treatment of acute liver failure (ALF) patients with the use of the Prometheus FPSA dialysis system.

MATERIALS AND METHODS

To January 2009, we performed 278 FPSA procedures in 114 patients, including 52 experience and ALF. The patients who underwent the FPSA procedure consisted of 32 women and 20 men of overall mean age of 33 +/- 12 years. The causes of ALF were: Wilson's disease (n = 15), unknown origin ALF (n = 11), amanita phalloides intoxication (n = 7), paracetamol intoxication (n = 8), acute hepatitis B virus (HBV)/hepatitis C virus (HCV) infection (n = 7), liver insufficiency after parenchymal resection (n = 2) drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome (n = 1), rabdomyolysis (n = 1), or primary nonfunction (PNF) after orthotopic liver transplantation (OLT) (n = 1). All procedures were performed using the Prometheus 4008H Fresenius Medical Care liver support system. The average number of treatments per patient was 2.41 and the average time for each FPSA treatment was 6.3 hours. The average heparin dose used during the procedure was 750 IU/h.

RESULTS

After the whole treatment regimen, we observed significant improvements in the biochemical results. The average concentrations improved: serum ammonia (before 249.2 mug/dL versus after 109.7 mug/dL); serum bilirubin (before 21.53 mg/dL versus after 8.81 mg/dL), serum aspartate aminotransferase (AST; before 2456.4 U/L versus after 1068.8 U/L); serum alanine aminotransferase (ALT; before 2958.2 U/L versus after 1595.8 U/L); serum urea (before 58.5 mg/dL versus after 21.1 mg/dL); serum creatinine (before 2.9 mg/dL versus after 1.7 mg/dL); and pH value (before 7.11 versus after 7.32). After Prometheus treatment OLT was performed in 33 patients. Among the 28 who survived (53.8%), 22 underwent OLT and 6 did not have OLT. Among the 24 patients who died (46.2%), 13 were before OLT and 11 after OLT.

CONCLUSION

The Prometheus 4008H Fresenius Medical Care Liver support system was useful method of detoxification for patients with ALF, serving as an element of pretransplantation care.

[Acute on chronic liver failure]

Acute-on-Chronic Liver Failure (ACLF) is a recently introduced term defined as severe acute deterioration of an established liver disease. This entity usually develops after an acute insult. The main clinical manifestations are hepatorenal syndrome, hepatic encephalopathy and organ failure, with a high risk of death in the short term. The true incidence of ACLF remains difficult to determine due to confusions surrounding the definition of this entity, but seems to be 40% at 5 years in patients with advanced cirrhosis, which translates into 4,000 cases in Europe within this time span. The treatment of choice is liver transplantation. However, due to the shortage of suitable organs and morbidity and mortality in these patients, other options must be used.

Liver support systems today

A májelégtelenség – akár korábbi májbetegség fennállása nélkül alakult ki (akut májelégtelenség), akár krónikus májbetegség akut dekompenzációja („akut a krónikuson” májelégtelenség) következménye – magas halálozással jár. A végállapotú májbetegségek következtében kialakult májelégtelenség egyetlen kuratív megoldása ma a májtranszplantáció. Ennek fő gátját a rendelkezésre álló donorszervek hiánya képezi, emiatt sok, várólistán szereplő beteg exitál. A transzplantáció korlátai tették szükségessé olyan májtámogató rendszerek kifejlesztését, amelyek alkalmasak a beteg életben tartására a szervátültetésig vagy a máj regenerációjáig. A korai próbálkozások (hemodialízis, hemoperfúzió, cseretranszfúzió, kereszthemodialízis, keresztkeringés, plazmaferézis stb.) elégtelennek bizonyultak. Napjainkban a májpótló kezelésnek két fő iránya alakult ki: a sejtalapú, úgynevezett bioarteficiális és a nem sejtalapú, úgynevezett arteficiális rendszerek. A bioarteficiális rendszerek élő állati májsejteket vagy emberi májtumorsejteket tartalmaznak. Jellegzetességük, hogy a beteg vérét vagy szeparált plazmáját a májsejteket tartalmazó bioreaktoron áramoltatják át. Elviekben a májműködést ezek a metodikák modellezik a legtökéletesebben, mert a máj szintetizáló- és detoxikálófunkcióját egyaránt pótolják. Jelenlegi formájukban azonban még távol állnak az ideális megoldástól, alkalmazásuk számos immunológiai, infektológiai, onkológiai és financiális problémát vet fel, ezért egyelőre csak kísérleti célra állnak rendelkezésre. Az arteficiális rendszerek a klinikum számára már elérhetőek, bár széles körben még nem terjedtek el. Csak a máj detoxikálófunkcióját pótolják, a szintetikus funkció részben a hiányzó anyagok (plazmaproteinek, alvadási faktorok) szubsztitúciójával pótolható. Idetartozik a hemodiabszorpció, amely az Amerikai Egyesült Államokban terjedt el (liver dialysis unit), valamint a főleg Európában használatos albumindialízis és a legújabban kifejlesztett frakcionált plazmaszeparáció és -adszorpció (FPSA). Az albumindialízis egyszerű módszere a „single pass albumin dialysis” (SPAD), ennek továbbfejlesztett változata a „molecular adsorbent recirculating system” (MARS). Az FPSA high-flux hemodialízissel kiegészített változata a Prometheus-rendszer. Bár a felsorolt módszerek hatásosságát számos kísérleti és klinikai tanulmány támasztja alá, a konzervatív kezeléssel szemben a túlélésre kifejtett előnyös hatásuk bizonyítására még nagy esetszámot felölelő, randomizált, kontrollált vizsgálatok elvégzésére van szükség.

The use of stem cells in liver disease

PURPOSE OF REVIEW

Cell transplantation to restore liver function as an alternative to whole liver transplantation has thus far not been successful in humans.

RECENT FINDINGS

Adult mature hepatocytes and various populations of liver progenitors and stem cells are being studied for their regenerative capabilities. Hepatocyte transplantation to treat metabolic deficiencies has shown promising early improvement in liver function; however, long-term success has not been achieved. Liver progenitor cells can now be identified and were shown to be capable to differentiate into a hepatocyte-like phenotype. Despite evidence of mesenchymal stem cell fusion in animal models of liver regeneration, encouraging results were seen in a small group of patients receiving autologous transplantation of CD133 mesenchymal stem cells to repopulate the liver after extensive hepatectomy for liver masses. Ethical issues, availability, potential rejection and limited understanding of the totipotent capabilities of embryonic stem cells are the limitations that prevent their use for restoration of liver function. The effectiveness of embryonic stem cells to support liver function has been proven with their application in the bioartificial liver model in rodents.

SUMMARY

There is ongoing research to restore liver function in cell biology, animal models and clinical trials using mature hepatocytes, liver progenitor cells, mesenchymal stem cells and embryonic stem cells.

7 Leverfalen

De lever vervult tal van essentiële functies in het menselijk lichaam, waaronder ontgifting van het bloed en aanmaak van diverse eiwitten en hormonen. Tevens speelt de lever een rol in het afweersysteem. Leverfalen kan omschreven worden als een situatie van onvoldoende werking van de lever bij deze processen. Dit beeld ontstaat wanneer door het verlies van functionele cellen het totale effectieve levervolume beneden een kritische grens komt. In dit hoofdstuk wordt ingegaan op diverse vormen van leverfalen en twee specifieke bij leverfalen voorkomende problemen, namelijk hepatische encefalopathie en verhoogde bloedingsneiging.