Comparison between bioartificial and artificial liver for the treatment of acute liver failure in pigs

AIM： To characterize and evaluate the therapeutic efficacy of bioartificial liver （BAL） as compared to that of continuous hemodiafiltration （CHDF） with plasma exchange （PE）, which is the current standard therapy for fulminant hepatic failure （FHF） in Japan. METHODS： Pigs with hepatic devascularization were divided into three groups： （1） a non-treatment group （NT; n = 4）; （2） a BAL treatment group （BAL; n = 4）, （3） a PE ＋ CHDF treatment group using 1.5 L of normal porcine plasma with CHDF （PE ＋ CHDF, n -- 4）. Our BAL system consisted of a hollow fiber module with 0.2 i~m pores and 1 × 10^10 of microcarrier-attached hepatocytes inoculated into the extra-fiber space. Each treatment was initiated 4 h after hepatic devascularization. RESULTS： The pigs in the BAL and the PE ＋ CHDF groups survived longer than those in the NT group. The elimination capacity of blood ammonia by both BAL and PE ＋ CHDF was significantly higher than that in NT. Aromatic amino acids （AAA） were selectively eliminated by BAL, whereas both AAA and branched chain amino acids, which are beneficial for life, were eliminated by PE ＋ CHDF. Electrolytes maintenance and acid-base balance were better in the CPE ＋ CHDF group than that in the BAL group. CONCLUSION： Our results suggest that PE ＋ CHDF eliminate all factors regardless of benefits, whereas BAL selectively metabolizes toxic factors such as AAA. However since PE ＋ CHDF maintain electrolytes and acid-base balance, a combination therapy of BAL plus CPE ＋ CHDF might be more effective for FHF.