Temporary extracorporeal liver assist devices based on liver cell cult
ures represent a promising approach for the treatment of liver failure
as well as for perioperative care in liver surgery and transplantatio
n. Primary hepatocytes from donor animals as well as human cell lines
have been discussed as cell sources. A viable cell mass of 110-220g (
= 2,5-5 x 10(10) liver cells) has to be functionally active in bioreac
tors over a time period of several days. This cell number correlates t
o 10 -20% of liver cells in an adult human liver. Neither in animal ex
periments, nor in clinical trials a complete liver replacement could y
et be shown for cell-based bioreactors, however beneficial effects hav
e been demonstrated: partial detoxification and specific synthetic fun
ctions have been reported in animal experiments. Two authors have show
n first preliminary clinical data on different cell-based liver assist
devices with influences on blood parameters and the neurological stat
us of treated patients. Nevertheless, clinical improvements also have
been achieved by using non-biological support, like charcoal-hemoperfu
sion and modified hemodialysis. In order to assess the influence of li
ver support devices on better results in therapy of liver failure, ran
domized clinical trials have to be performed. Prior to this, artificia
l liver support systems have to demonstrate their biocompatibility and
biosafety for clinical use as well as their efficacy and availability
.