Artificial Liver Support

Acute liver failure (ALF) and acute-on-chronic liver failure (ACLF) both have high mortality rates without liver transplantation. Artificial liver support systems may benefit patients with liver failure, serving as a bridge to transplantation or as a destination therapy allowing recovery. There are currently two types of artificial liver support systems: non-biological and biological. Non-biological artificial liver (NBAL) support systems primarily focus on detoxification by removing toxins through selective membranes and adsorbent materials. Well-known NBAL systems are plasma exchange, Molecular Adsorbent Recirculating System (MARS), Single-Pass Albumin Dialysis (SPAD), and the Fractionated Plasma Separation and Adsorption System (Prometheus). NBAL therapies consistently reduce bilirubin and improve encephalopathy; however, pivotal randomized controlled trials such as RELIEF (MARS) and HELIOS (Prometheus) did not confirm a survival advantage, although plasma exchange improved transplant-free survival in acute liver failure. Biological artificial liver (BAL) support systems use human or animal-derived hepatocytes to temporarily replace liver function, including the Extracorporeal Liver Assist Device (ELAD), HepatAssist, and stem-cell-based systems. Early BAL studies showed biochemical and neurological improvements, but large trials such as VTL-308 failed to demonstrate a significant survival benefit over standard medical therapy. Overall, while NBAL and BAL therapies can improve encephalopathy, renal function, and cholestasis, current evidence does not show a clear mortality benefit, and artificial liver support systems remain supportive rather than curative.