Acute-on-chronic liver failure: extracorporeal liver assist devices.

PURPOSE OF REVIEW: Acute-on-chronic liver failure (ACLF), a syndrome precipitated by acute liver injury in patients with advanced cirrhosis, is associated with multiorgan dysfunction and high rates of mortality. Liver support systems have been developed in an attempt to improve survival of patients with ACLF by providing a bridge until recovery of the native liver function. RECENT FINDINGS: Nonbiological devices such as molecular adsorbent recirculating system (MARS) and fractionated plasma separation and adsorption (Prometheus) are effective in improving severe hepatic encephalopathy and cholestasis, have good safety and tolerability profiles and are frequently employed in patients with ACLD; however, randomized controlled trials (RCTs) failed to show improvement in survival. Biologic devices that incorporate hepatic cells in bioreactors are also under development. Recent data from pilot studies suggested improvement in survival rates in some groups of patients with ACLF; however, their effect on patient survival in RCT is still unknown. SUMMARY: Liver support systems are safe and well tolerated when used in management of patients with ACLF. Their use should continue in controlled clinical trials to explore their role in bridging patients to liver transplantation or recovery in well defined patient groups.