[Extracorporeal liver support systems]

Acute liver failure is very life-threatening since the conventional medical treatments have little effects on the clinical outcome. Artificial liver support systems based on blood detoxification alone have proven ineffective because they cannot correct the severe biochemical disorders. An effective liver support system should be capable of carrying out essential functions such as phase I reaction in which lipid-soluble toxic substance are rendered water-soluble by the enzyme system of the cytochrome P450 and NADPH-cytochrome reductase, and are therefore conjugated by the phase II reaction, before excretion. Liver support systems should be capable of sustaining patients with fulminant liver failure until an organ is available for liver transplantation (bridging treatment), or improving the survival in patients for whom liver transplantation is not a therapeutic option. Recent advances in cell biology and tissue culture techniques have led the way for potential clinical use of isolated hepatocytes so that they are now an important element of bioartificial liver support devices. Some of these systems are currently under clinical investigation in the USA and Europe, and the results of the prospective controlled trials will be soon available.