Artificial liver support in acute and acute-on-chronic liver failure

Liver failure is a life-threatening condition, and an artificial liver is highly desirable to replace the failing liver-functions in the waiting time for liver regeneration to happen or until liver transplantation can be undertaken. This review focuses on the efficacy of using artificial extracorporeal liver support devices.Artificial liver support devices such as the molecular adsorbent recirculating system (MARS), fractionated plasma separation and adsorption, and therapeutic plasma exchange (TPE) are well tolerated. MARS and TPE improve systemic haemodynamics and the grade of hepatic encephalopathy. However, randomized, controlled trials of MARS and fractionated plasma separation and adsorption have failed to show improvement in survival in patients with acute liver failure (ALF) and patients with acute-on-chronic liver failure (ACLF). Only TPE improves survival in patients with ALF by ameliorate the release of ammonia, damage-associated molecular patterns and sB7 (CD80/86) from the necrotic liver. No randomized, controlled trials on survival in patients with ACLF using TPE have been done.Liver support systems such as MARS and TPE may temporarily improve systemic haemodynamics and the degree of encephalopathy. However, TPE is the only procedure that improves survival in patients with ALF. The role of TPE in ACLF remains unknown.