Evaluation of the Hepa Wash® treatment in pigs with acute liver failure

Background: Mortality of patients with acute liver failure (ALF) is still unacceptably high. Available liver support systems are still of limited success at improving survival. A new type of albumin dialysis, the Hepa Wash (R) system, was newly introduced. We evaluated the new liver support system as well as the Molecular Adsorbent Recycling System (MARS) in an ischemic porcine model of ALF. Methods: In the first study animals were randomly allocated to control (n=5) and Hepa Wash (n=6) groups. In a further pilot study, two animals were treated with the MARS-system. All animals received the same medical and surgical procedures. An intraparenchymal intracranial pressure was inserted. Hemodynamic monitoring and goal-directed fluid therapy using the PiCCO system was done. Animals underwent functional end-to-side portacaval shunt and ligation of hepatic arteries. Treatment with albumin dialysis was started after fall of cerebral perfusion pressure to 45 mmHg and continued for 8 h. Results: All animals in the Hepa Wash group survived the 13-hour observation period, except for one that died after stopping treatment. Four of the control animals died within this period (p=0.03). Hepa Wash significantly reduced impairment of cerebral perfusion pressure (23 +/- 2 vs. 10 +/- 3 mmHg, p=0.006) and mean arterial pressure (37 +/- 1 vs. 24 +/- 2 mmHg, p=0.006) but had no effect on intracranial pressure (14 +/- 1 vs. 15 +/- 1 mmHg, p=0.72). Hepa Wash also enhanced cardiac index (4.94 +/- 0.32 vs. 3.36 +/- 0.25 l/min/m2, p=0.006) and renal function (urine production, 1850 +/- 570 vs. 420 +/- 180 ml, p=0.045) and eliminated water soluble (creatinine, 1.3 +/- 0.2 vs. 3.2 +/- 0.3 mg/dl, p=0.01; ammonia 562 +/- 124 vs. 1382 +/- 92 mu g/dl, p=0.006) and protein-bound toxins (nitrate/nitrite 5.54 +/- 1.57 vs. 49.82 +/- 13.27 mu mol/l, p=0.01). No adverse events that could be attributed to the Hepa Wash treatment were observed. Conclusions: Hepa Wash was a safe procedure and improved multiorgan system failure in pigs with ALF. The survival benefit could be the result of ameliorating different organ functions in association with the detoxification capacity of water soluble and protein-bound toxins.