In order to achieve a higher degree of improvement in patients with postoperative hepatic failure, the effects of plasma adsorption (PA) using a serial connection of noncoated charcoal (N 350) and a new bilirubin adsorbent material, styrenedivinylbenzene (BR350), were investigated both experimentally and clinically. After in vitro perfusion of high bilirubin containing plasma through these columns for 3 hours, total bilirubin levels were drastically reduced to 21% of the preperfusion level in the serial connection of N 350 and BR 350, while it remained high at over 40% in the single use of each column. Total branched chain and aromatic amino acid levels were also drastically reduced in the serial connection of these columns to 50, 40, and 7%, respectively, while the total amino acid levels remained high at 87% in the single use of BR 350. The combination of these columns enhanced rather than interfered with one another. Patients who received this treatment achieved an initial reduction of plasma total bilirubin and aromatic amino acids of 57 +/- 6 and 84 +/- 7, respectively. Although the long-term prognosis for these patients was negative, improvement of clinical and laboratory findings were actually obtained by this treatment. This PA system could provide a possibility for an improved supportive therapy for hepatic failure, especially for patients with hepatic coma and hyperbilirubinemia.