Artificial and bioartificial liver support: a review of perfusion treatment for hepatic failure patients

Abstract

Liver transplantation and blood purification therapy, including plasmapheresis, hemodiafiltration, and bioartificial liver support, are the available treatments for patients with severe hepatic failure. Bioartificial liver support, in which living liver tissue is used to support hepatic function, has been anticipated as an effective treatment for hepatic failure. The two mainstream systems developed for bioartificial liver support are extracorporeal whole liver perfusion (ECLP) and bioreactor systems. Comparing various types of bioartificial liver in view of function, safety, and operability, we concluded that the best efficacy can be provided by the ECLP system. Moreover, in our subsequent experiments comparing ECLP and apheresis therapy, ECLP offers more ammonia metabolism than HD and HF. In addition, ECLP can compensate amino acid imbalance and can secret bile. A controversial point with ECLP is the procedure is labor intensive, resulting in high costs. However, ECLP has the potential to reduce elevated serum ammonia levels of hepatic coma patients in a short duration. When these problems are solved, bioartificial liver support, especially ECLP, can be adopted as an option in ordinary clinical therapy to treat patients with hepatic failure.

Figure 1

Cross dialysis treatment using four living dogs (Hori et al 1958).

Figure 2

ECLP applied for acute phosphorus intoxication patient (Kawamura et al 1974).

Figure 3

ECLP using baboon or porcine livers (Ozawa et al 1982).

Figure 4

ECLP using porcine livers (Teraoka et al 1985).

Figure 5

Ex vivo direct hemoperfusion experiment of ECLP (Naruse et al).

Figure 6

Comparison of efficacy between ECLP and apheresis therapy. (A): Ammonia; (B) Fischer’s ratio. ○: Control group; ●: Hemofiltration (HF) group; □:hemodialysis (HD) group; ■: ECLP group.