Importance of the extracorporeal circulation rate in a bioartificial liver

A bioartificial liver (BAL) is an extracorporeal medical device which incorporates living hepatocytes in a cartridge. Most efforts have been exerted to develop a BAL cartridge with high metabolic functions. However, little attention has been paid to a extracorporeal circulation rate. In this study, equations by which we can predict the operation conditions of the BAL system for the effective treatment of patients with severe liver failure were derived from pharmacokinetic considerations. Toxins of which intrinsic clearance in the healthy person is more than several hundred milliliters/minute cannot be effectively removed from the blood under the low extracorporeal circulation rate even though the BAL cartridge has high metabolic functions. We do not deny the importance of developing the BAL cartridge with high metabolic functions, but much attention should be also paid to the extracorporeal circulation rate for the effective treatment of the patient with severe liver failure.