Background:
The Molecular Adsorbent Recirculating System (MARS) represents an attractive artificial liver support system for the treatment acute liver insufficiency. However, neither clear indications for the initiation of MARS treatment (i.e. after major hepatic resections) nor criteria for discontinuation of therapy have so far been evaluated. We therefore prospectively analyzed clinical data of all our surgical patients with MARS treatment.

Patients and Methods:
All surgical patients receiving MARS treatment were included in the study. Indications for MARS therapy were liver insufficiency, asterixis, and hepatic encephalopathy in four patients after major hepatic resections (2 cholangio-carcinoma, 1 hepatocellular carcinoma (HCC), 1 gallbladder carcinoma), hepatic encephalopathy due to late onset hepatic failure, primary non-function (PNF) after OLT (n=1), and hepatic support after OLT (Steatotic graft, n=1). Blood and albumin flow in the MARS unit was adjusted between 150 and 250ml/min. Heparin was administered to maintain activated clotting time (ACT) > 100 sec.

Results:
Within 24 months seven surgical patients received a total of 23 MARS treatments. Two patients were successfully bridged to OLT or Re-OLT for PNF of the hepatic graft. From five patients supported during liver regeneration after major hepatic surgery, and after OLT of a steatotic graft, three survived and were dismissed 17, 31, and 47 days after MARS. In two patients (Resection for HCC in cirrhotic liver, extended resection of gallbladder carcinoma) MARS therapy was discontinued (after two, and five cycles) due to lack of overall improvement of the clinical situation. These patients died one and two days later. No severe adverse effects were encountered during a total of 166 hours of MARS treatment. Important prognostic factors for survival were a significant rise of factor V levels > 40%, and a total heparin dose > 3000 IE during an 8 hour MARS cycle.

Conclusions:
MARS therapy is safe and can be effective for the treatment of surgically induced liver insufficiency. Prognostic factors for survival identified in our patients were a rise of factor V levels and the need of increasing heparin administration during consecutive MARS cycles. MARS therapy is a valuable therapeutic tool in the surgical hepato-biliary unit.