Artificial liver support: potential to retard regeneration?

HYPOTHESIS The concept of an "artificial liver" has been in development for over 40 years. Such devices aim to temporarily assume metabolic and excretory functions of the liver, with removal of potentially hepatotoxic substances, thereby clinically stabilizing patients and preventing deterioration while awaiting transplantation. If sufficient numbers of viable hepatocytes remain, regeneration and subsequent recovery of innate liver function may occur. However, these devices have not yet become part of routine clinical use. Much less is known regarding the effect such devices have, if any, on circulating cytokines and growth factors and the subsequent effects on the regenerating liver. If these devices remove or reduce factors known to promote regeneration, is the rate of regeneration retarded? Conversely, does the incorporation of hepatocytes into bioartificial support systems confer an advantage through the production of growth-promoting factors from these cultured hepatocytes?Data Sources, Extraction, and STUDY SELECTION Data were obtained using PubMed search for reports involving liver support, extracorporeal circuits, dialysis, growth factors, and cytokines. Those reports specifically looking at the effect of artificial liver support on cytokines and growth factors are discussed. CONCLUSIONS There is a paucity of information on the key events and substances involved in hepatic regeneration. In addition, there is a potential impact of liver support devices on the regeneration of substances associated with hepatic regeneration. Further study is needed.