Liver Assist Devices
for treatment of liver failure
Further Development
The development of bioartificial liver assist devices has offered promising clinical outcomes. However, the current devices have made little impact on improving patient survival. The function of the liver is very difficult to replace and current approaches are limited by factors such as the cell source, total liver cell mass, mass exchange efficiency, and the total flow rates of the entire system. A highly functional, and reliable cell source still must be found. Currently, human primary hepatocytes are in short supply and hepatoblastoma based cells such as the ones found in the ELAD device show limited metabolic function. Porcine hepatocytes carry the risk of infection from zoonoses. Stem cells may be able to offer a reliable, highly metabolically active cell source in the future. Total cell mass is another issue that must be addressed in future liver assist devices. Current cell masses used in bioartificial livers of 50–500g are not sufficient for proper liver function. Transplantation studies have shown that a minimum cell mass of about 40% of the patient’s ideal liver mass (approximately 1500 g) is necessary to assure proper function. Improvements to the current devices will need to address these issues in order to increase effectiveness.
References
Stadlbauer V. Jalan R. Acute liver failure: liver support therapies. Current Opinion in Critical Care, Vol 13 (2007)
Pless G. Sauer I.M. Bioartificial Liver: Current Status. Transplantation Proceedings, Vol 37 (2005)
Chamuleau R. et al. Which are the right cells to be used in a Bioartificial Liver?. Metabolic Brain Disease, Vol 20 (2005)
Demetriou AA. et al. Prospective, randomized, multicenter, controlled trial of a bioartificial liver in treating acute liver failure, Ann Surg 239 (2004)
Sauer I.M. et al. Extracorporeal liver support based on primary human liver cells and albumin dialysis, J Hepatol 39 (2003)
Sauer I. M. et al. Primary human liver cells as source for modular extracorporeal liver support, Int J Artif Org 25 (2002)
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