Fulminant hepatic failure bridged to liver transplantation with a molecular adsorbent recirculating system: a single-center experience

Ex vivo resection of hepatic neoplasia and autotransplantation: a case report and review of the literature

INTRODUCTION

Ex situ liver resection is an uncommon procedure but offers an opportunity for R0 surgical resection of liver tumors that are otherwise unresectable. Liver insufficiency following extensive resections is a risk in this patient population; consequently, all measures should be taken to prevent this highly morbid complication.

METHOD

We report a case of a patient with an extensive cholangiocarcinoma involving all three hepatic veins that required ex vivo resection and liver autotransplantation to achieve an R0 resection. Postoperatively, the patient demonstrated signs of worsening liver function that, in addition to standard medical therapy, underwent a brief treatment with molecular adsorbent recirculating system (MARS) therapy.

RESULTS

Although the role of MARS remains unclear, the patient tolerated it well and her liver graft dysfunction and hepatic encephalopathy slowly resolved. The patient was discharged to a rehabilitation facility. She is currently alive and well with no evidence of recurrence 3 years later.

CONCLUSION

We present a review of the literature on ex situ resection and liver autotransplantation. In addition to numerous case reports, there are a few moderate series of ex situ resection and autotransplantation. We suggest that the use of artificial liver devices, if indicated, in the postoperative ex situ resection liver autotransplant patient may assist in the support of the patient while the transplanted liver remnant recovers.

Artificial and bioartificial liver support

The fact that liver failure constitutes a life-threatening condition and can, in most cases, only be overcome by orthotopic liver transplantation, lead to the development of various artificial and bioartificial liver support devices. While artificial systems are based on the principles of adsorption and filtration, the more complex concept of bioartificial devices includes the provision of liver cells. Instead of solely focussing on detoxification, these concepts also support the failing organ concerning synthetic and regulative functions.The systems were evaluated in a variety of clinical studies, demonstrating their safety and investigating the impact on the patient's clinical condition. This review gives an overview over the most common artificial and bioartificial liver support devices and summarizes the results of the clinical studies.

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.

Pre-operative risk factors predict post-operative respiratory failure after liver transplantation

Objective

Post-operative pulmonary complications significantly affect patient survival rates, but there is still no conclusive evidence regarding the effect of post-operative respiratory failure after liver transplantation on patient prognosis. This study aimed to predict the risk factors for post-operative respiratory failure (PRF) after liver transplantation and the impact on short-term survival rates.

Design

The retrospective observational cohort study was conducted in a twelve-bed adult surgical intensive care unit in northern Taiwan. The medical records of 147 liver transplant patients were reviewed from September 2002 to July 2007. Sixty-two experienced post-operative respiratory failure while the remaining 85 patients did not.

Measurements and Main Results

Gender, age, etiology, disease history, pre-operative ventilator use, molecular adsorbent re-circulating system (MARS) use, source of organ transplantation, model for end-stage liver disease score (MELD) and Child-Turcotte-Pugh score calculated immediately before surgery were assessed for the two groups. The length of the intensive care unit stay, admission duration, and mortality within 30 days, 3 months, and 1 year were also evaluated. Using a logistic regression model, post-operative respiratory failure correlated with diabetes mellitus prior to liver transplantation, pre-operative impaired renal function, pre-operative ventilator use, pre-operative MARS use and deceased donor source of organ transplantation (p<0.05). Once liver transplant patients developed PRF, their length of ICU stay and admission duration were prolonged, significantly increasing their mortality and morbidity (p<0.001).

Conclusions

The predictive pre-operative risk factors significantly influenced the occurrence of post-operative respiratory failure after liver transplantation.

Cost-utility of molecular adsorbent recirculating system treatment in acute liver failure

AIM: To determine the short-term cost-utility of molecular adsorbent recirculating system (MARS) treatment in acute liver failure (ALF).

METHODS: A controlled retrospective study was conducted with 90 ALF patients treated with MARS from 2001 to 2005. Comparisons were made with a historical control group of 17 ALF patients treated from 2000 to 2001 in the same intensive care unit (ICU) specializing in liver diseases. The 3-year outcomes and number of liver transplantations were recorded. All direct liver disease-related medical expenses from 6 mo before to 3 years after ICU treatment were determined for 31 MARS patients and 16 control patients. The health-related quality of life (HRQoL) before MARS treatment was estimated by a panel of ICU doctors and after MARS using a mailed 15D (15-dimensional generic health-related quality of life instrument) questionnaire. The HRQoL, cost, and survival data were combined and the incremental cost/quality-adjusted life years (QALYs) was calculated.

RESULTS: In surviving ALF patients, the health-related quality of life after treatmeant was generally high and comparable to the age- and gender-matched general Finnish population. Compared to the controls, the average cost per QALY was considerably lower in the MARS group (64 732€vs 133 858€) within a timeframe of 3.5 years. The incremental cost of standard medical treatment alone compared to MARS was 10 928€, and the incremental number of QALYs gained by MARS was 0.66.

CONCLUSION: MARS treatment combined with standard medical treatment for ALF in an ICU setting is more cost-effective than standard medical treatment alone.

A new prognostic formula for adult acute liver failure using computer tomography-derived hepatic volumetric analysis

BACKGROUND/AIMS

King's College Hospital (KCH) criteria and the model for end-stage liver disease (MELD) score are useful and widely-employed prognostic markers for acute liver failure (ALF). We previously reported that liver atrophy is an important prognostic factor for ALF. The aim of the present study was to assess the value of liver volumetry and to generate a new prognostic formula.

METHODS

Computed tomography-derived liver volume (CTLV) and standardized liver volume (SLV) of 30 adult ALF patients were calculated at the time of diagnosis. Patients were assigned to one of two groups: group A consisted of 13 patients who recovered without surgical intervention, and group B consisted of 17 patients who died due to liver failure or who underwent living donor liver transplantation (LDLT).

RESULTS

The median CTLV/SLV ratios of groups A and B were 1.019 and 0.757, respectively (P = 0.0009). The difference was most significant (P = 0.0002) at the probability cutoff point of 0.80 for CTLV/SLV ratio; the sensitivity and specificity were 76.5% and 92.3%, respectively. Serum total bilirubin (TB) levels and CTLV/SLV ratio were selected as independent prognostic factors by multivariate analysis. A prognostic formula including volumetric analysis was established: Z = -2.3813 - [0.15234 x TB (mg/dl)] + [4.5734 x CTLV/SLV] (AUC = 0.87783, P = 0.0002).

CONCLUSIONS

The CTLV/SLV ratio is a very useful marker for predicting the prognosis of adult ALF. Our prognostic formula including only the CTLV/SLV ratio and TB is simple and useful and awaits validation in a future larger-scale prospective study.

Acetaminophen hepatotoxicity and acute liver failure

Acetaminophen-induced hepatotoxicity is a common consequence of acetaminophen overdose and may lead to acute liver failure (ALF). Currently acetaminophen is the most common cause of ALF in both United States and United Kingdom, with a trend to increasing incidence in the United States. N-acetylcysteine is the most effective drug to prevent progression to liver failure with acetaminophen hepatotoxicity. Liver transplantation is the only definitive therapy that will significantly increase the chances of survival for advanced ALF. This communication reviews current information regarding causes and management of acetaminophen-induced hepatotoxicity and ALF.

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

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

The therapeutical efficiency of the newest extracorporal elimination procedure (Prometheus® treatment) in acute liver failure caused by intoxication

Az akut májelégtelenség mortalitása az intenzív terápia ellenére májtranszplantáció nélkül 60–90%. Az átültethető szervek korlátozott száma miatt azonban a betegek jelentős része a várólistán exitál. A mortalitás csökkentése érdekében számos próbálkozás történt a májelégtelenségben felhalmozódó albuminhoz kötött és vízoldékony méreganyagok eltávolítására, elősegítve ezzel a máj spontán regenerációját, illetve a beteg életben tartását a májtranszplantációig. A Prometheus®-kezelés egy viszonylag új technika, a frakcionált plazmaszeparáció és -adszorpció (FPSA) és egy high-flux dialízis kombinációja. Az eljárás során a beteg saját, szeparált, albuminban gazdag plazmája speciális adszorbereken halad keresztül, lehetővé téve az albuminhoz kötött toxinok eliminációját, miközben a vízoldékony toxinok eltávolítása hemodialízissel történik. Célkitűzés: A szerzők szándéka az volt, hogy a Prometheus®-kezelés hatékonyságát igazolják mérgezés okozta akut májelégtelenségben. Betegek és módszer: A Prometheus®-kezelést három, konzervatív kezeléssel nem uralható akut májelégtelenségben szenvedő, súlyos, paracetamol-, káliumpermanganát- és Amanita phalloides-mérgezett beteg esetében alkalmazták. Eredmények: A három nőbetegnél 10 kezelés történt. Súlyos szövődményt nem észleltek. A kezelések során az albuminhoz kötött (indirekt bilirubin p = 0,048; epesav p = 0,001) és a vízoldékony (direkt bilirubin p = 0,002; kreatinin p = 0,007) toxinok szignifikáns csökkenését tapasztalták. Az ammónia, a karbamid, a fibrinogén és az antitrombin III szint szignifikánsan nem változott. Mindhárom beteg májtranszplantáció nélkül meggyógyult. Következtetés: A Prometheus®-kezelés hatékonyan távolítja el az akut májelégtelenségben akkumulálódó toxinokat. Biztonságos eljárás. Konzervatív terápiával nem uralható esetekben lehetővé teszi a beteg életben tartását a máj spontán regenerációjáig vagy a májtranszplantációig.

MARS dialysis in decompensated alcoholic liver disease: a single-center experience

Acute decompensation of chronically stable alcoholic liver disease (ALD) is the most common cause of terminal liver failure in developed countries. Molecular adsorbent recirculation system (MARS) is increasingly used as artificial liver support to facilitate spontaneous organ recovery. However, the experience to date and the evidence to justify this therapeutic strategy in acutely decompensated ALD are still insufficient. We report our clinical experience with MARS in 14 patients with acutely decompensated ALD (6 male subjects; median age [interquartile range], 51 [47-56] years; Child-Pugh score, 12 [10-13]; Acute Physiology and Chronic Health Evaluation (APACHE) II score, 20 [18-24]) and severely impaired liver function whose disease was unresponsive to conventional supportive care. At least 3 sessions were applied in any patient (48 sessions in total). Under MARS treatment, the following levels decreased: bilirubin (544 [489-604] to 242 [178-348] micromol/L; P<0.001), creatinine (212 [112-385] to 91 [66-210] micromol/L; P=0.002), cholestatic parameter gamma-glutamyl transpeptidase (5.9 [1.8-13.1] to 4.6 [1.8-8.3] micromol/L) (P<0.001), blood urea nitrogen (56 [32-91] to 34 [21-68] mmol/L; P=0.044), and platelet count (176 [85-241] to 84 [31-145] Gpt/L; P=0.004). In contrast, MARS failed to improve daily urine output (P=0.846), ammonia levels (P=0.340), or thromboplastin time (P=0.775). Only 3 patients survived the hospital stay (mortality 78.6%). Although MARS improved laboratory parameters of hepatic detoxification and renal function in patients with acutely decompensated ALD, the patients' mortality remained unsatisfactorily high. Our experience does not support the indiscriminative use of MARS in acutely decompensated ALD without further controlled studies.

Anticoagulation Minimization Is Safe and Effective in Albumin Liver Dialysis Using the Molecular Adsorbent Recirculating System

The molecular adsorbent recirculating system (MARS) is a blood purification device with renal and hepatic dialytic effects. This study examined the use of low-dose unfractionated heparin in MARS. This was a prospective, observational study of 15 MARS treatment sessions (mean duration per treatment cycle = 12.2 +/- 4.5 h) in four patients with severe acute decompensation of chronic liver disease (n = 3) and fulminant hepatic failure (n = 1) treated with intermittent MARS. All patients were critically ill (APACHE II 24.8 +/- 3.3). Renal dialysis was with continuous hemofiltration and/or slow low-efficiency dialysis. One MARS session was terminated because of vascular access occlusion (1/15; 6.7%). Bleeding was noted in two sessions (2/15; 13%). Twelve MARS sessions were heparin-free and three treatments were with mean heparin dose of 833 +/- 382 IU. Serum biochemical parameters pre- and post-MARS were total bilirubin (micromol/L): 409.4 +/- 141.6 versus 282.9 +/- 90, P < 0.05; plasma ammonia (micromol/L): 44.3 +/- 21.2 versus 28.8 +/- 20.2, P = 0.002; urea (mmol/L): 15.9 +/- 11.8 versus 7.9 +/- 6.6, P = 0.002; creatinine (micromol/L): 252.4 +/- 151.9 versus 150.1 +/- 96.6, P = 0.003. Pre-MARS versus post-MARS systolic (SBPs) and diastolic (DBPs) blood pressures (mm Hg) were SBP = 129.2 +/- 27.7 versus 124 +/- 25, P = 0.838; and DBP = 60.7 +/- 15.3 versus 56 +/- 13, P = 0.595. Prothrombin time (PT), activated partial thromboplastin time (aPTT) and platelet count (Plt) pre- and post-MARS were PT(s): 22 +/- 7.9 versus 23.8 +/- 10.2, P = 0.116; aPTT (s): 64.5 +/- 40.9 versus 85.5 +/- 50.6, P = 0.092; and Plt (x10(3)/mm(3)): 87 +/- 67.6 versus 68.8 +/- 39, P = 0.098. MARS priming with heparin saline was safe. Heparin-minimized MARS did not compromise circuit function and longevity in extended intermittent MARS.

Epidemiology of acute liver failure

Acute liver failure (ALF) is an uncommon disorder that leads to jaundice, coagulopathy, and multisystem organ failure. Its definition is based on the timing from onset of jaundice to encephalopathy. In 2005, ALF accounted for 6% of liver-related deaths and 7% of orthotopic liver transplants (OLT) in the United States. Several classification systems have been developed for ALF, with the King's College criteria most widely used for prediction of OLT. Specific diagnostic tests should be implemented to identify the cause of ALF, which will help to determine its treatment and prognosis. Viral hepatitis was previously reported to be the most common cause of ALF in the United States, but acetaminophen overdose and idiosyncratic drug reactions have emerged as the most frequent causes in recent studies. Malignancy is an uncommon cause of ALF, and thus imaging studies may not be useful in this setting, but liver biopsy may be beneficial in selected cases. An overall strategy for ALF should start with identifying the cause, assessing the prognosis, and early transfer to a transplantation center for suitable candidates. OLT has emerged as a life-saving procedure leading to marked improvement in survival rates. Improved surgical techniques, immunosuppression, and comprehensive care have led to an overall survival rate of approximately 65% with OLT. N-acetylcysteine is effective in ALF caused by acetaminophen overdose, with results strongly related to how soon it is given rather than the route of administration. Liver support systems show potential for the treatment of ALF, but their role needs validation in large multicenter randomized trials.

MARS: a futile tool in centres without active liver transplant support

BACKGROUND AND AIM

Studies on Molecular Adsorbent Recycling Systems (MARS) showed inconclusive survival benefits.

PATIENTS AND METHOD

We evaluated the efficacy of MARS for patients with either acute liver failure (ALF) or acute-on-chronic liver failure (AoCLF) at our centre, from February 2002 till April 2006 retrospectively.

RESULTS

Fifty ALF patients underwent median (range) three (1-10) sessions of MARS. Acute exacerbations of chronic hepatitis B (n=26) and drug-induced liver injury (n=12) were the commonest causes. Living donors were available in 6, 2 paediatric patients underwent left lobe and four adults underwent right lobe living donor liver transplant. Among the 44 ALF patients without a suitable living donor, one underwent deceased donor liver transplant and survived, another 19-year-old male with acute exacerbations of chronic hepatitis B recovered without transplant, and the rest died. Twenty-six had AoCLF and underwent four (1-10) MARS sessions. Sepsis (n=16) and upper gastrointestinal bleeding (n=4) were the commonest precipitating factors. None had a suitable living or deceased donor, suitable for transplantation during their hospitalization. Only one of 26 AoCLF patients survived the hospitalization, but the survivor died of sepsis 1 month later.

CONCLUSION

In this non-randomized study, survival after MARS was related to the availability of transplant, and in patients where living or deceased donor transplant was unavailable, MARS was of little benefit. Randomized-controlled trials on MARS((R)) are urgently needed to clarify its clinical utility.

Molecular Adsorbent Recirculating System in Liver Transplantation: Safety and Efficacy

We assessed the safety and clinical efficacy of the Molecular Adsorbent Recirculating System (MARS) in liver failure patients admitted to our intensive care unit (ICU) from May 2000 to February 2006. Of 28 adult patients with bilirubin >15 mg/dL and hepatic encephalopathy (HE) grade > or =2 or hepato-renal syndrome, 22 patients were included in the study, because 6 patients were older than 65 years of age or showed recent alcohol abuse or extrahepatic malignancy. Patients were assigned to 2 groups according to whether MARS therapy was associated with a transplantation procedure: 11 patients received MARS therapy and liver transplantation (OLT group) and 11 patients received MARS therapy alone (non-OLT group). Five of 11 patients in the OLT group were listed for transplantation and 6 patients with graft failure for retransplantation. The patients in the OLT and non-OLT groups were similar in MELD, SOFA, and SAPS scores. All patients were stable and free from complications. MARS significantly reduced bilirubin, bile acids, and blood urea nitrogen (BUN) levels in both groups (P < .05), whereas a significant decrease in ammonia level was observed in the OLT group. Patient survival rates at 3 and 6 months in the OLT group were 91% and 73%, respectively, and in the non-OLT group, 9% and 9%, respectively (P < .001). MARS was safe and well tolerated, improving biochemical parameters, neurological function, and pruritus. In terms of survival, the use of MARS alone was not effective due to the high rate of multiple organ failure. Nevertheless, the association of MARS with a transplant/retransplantation procedure was highly effective.