PROSPECTS FOR EXTRACORPOREAL LIVER SUPPORT

This present review is timely with the increasing use of the molecular adsorbents recirculating system (MARS) for the management of liver failure, with over 3000 patients having been treated with this device worldwide. In the UK, MARS is being used for the treatment of individual patients both in the National Health Service and also in the private sector. In order to investigate the latest position with respect to bioartificial liver devices, a meeting was held at University College London Hospital in September 2003 and this article is based on the most up to date data presented there. Liver failure, whether of the acute variety with no pre-existing liver disease (acute liver failure (ALF)) or an acute episode of decompensation superimposed on a chronic liver disorder (acute on chronic liver failure (ACLF)), carries a high mortality. In patients with ALF, lack of detoxification, metabolic, and regulatory functions of the liver leads to life threatening complications, including kidney failure, encephalopathy, cerebral oedema, severe hypotension, and susceptibility to infections culminating in multiorgan failure.1 The only established therapy for such patients is liver transplantation (LTx) but currently one third of these patients die while waiting for a transplant and the organ shortage is increasing (fig 1).2 However, liver failure, whether of the acute or acute on chronic variety, is potentially reversible, and considerable work has been carried out over many years to develop effective liver support devices. Figure 1 Annual death rates on the waiting list for liver transplantation between 1997 and 2001 in UNOS categories 1 (acute/fulminant liver failure), 2a (decompensated chronic liver disease urgently requiring transplant), and 2b (decompensated chronic liver disease requiring transplant less urgently). (Source: OPTN/SRTR data, as of 1 August 2002.) The development of these devices has been approached in two very different ways. The biological devices, which aim …