[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 effective treatment of ALF. Numerous attempts have been made to improve survival by using various extracorporeal support techniques, but none of these therapeutic approaches was able to increase the survival rate. Liver support systems based on detoxification procedures only could not influence the deleterious course of the disease. It is certain that an ideal liver support system should be capable to fulfil the liver's essential synthetic and metabolic 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 first clinical applications.