Extracorporeal liver assist devices in acute liver failure

The acute liver failure (ALF) is a complex syndrome resulting from loss of synthetic and metabolic functions of the liver. Despite recent advances in intensive care medicine patients with severe ALF have a very high mortality and the orthotopic liver transplantation still remains the only proven eff ective treatment of ALF. Numerous attempts have been made to improve surviv al by using various extracorporeal support techniques,but none of these the rapeutic approaches was able to increase the survival rate. Liver support s ystems based on detoxification procedures only could not influence the dele terious course of the disease. It is certain that an ideal liver support sy stem should be capable to fulfil the liver's essential synthetic and metabo lic functions as well as detoxification and excretion. Over the last years the development of hybrid liver assist devices has aimed at replacing these liver functions and therefore might give an advantage over earlier systems based on detoxification techniques only. This article gives a short review of the various liver support systems and focuses then on the hybrid liver support systems, their construction and the remaining problems after the fi rst clinical applications.