Development of an isolated perfusion circuit with double bypass using automatic blood pumps

Isolated perfusion of the liver is a useful and promising therapeutic method for various hepatic diseases. However, conventional techniques using a roller pump require a large priming volume and cannot run at the low flow rate without complications. These disadvantages do not allow the use of conventional techniques in smaller pediatric patients. The authors solved these problems successfully for the first time by using unique sac-type air-driven automatic blood pumps with an oxygenator primed with a blood volume of 65 ml in the total circuit. The usefulness of these blood pumps for liver perfusion was evaluated in small animals weighing 3.5-6.0 kg. A hepatic perfusion circuit was established between the portal vein and the inferior vena cava. The blood pumps worked well without any trouble, and stable flow could be maintained. No hepatocellular damage or anaerobiosis of the liver was observed at a hepatic perfusion flow rate of 20 ml/min/kg. Isolated liver perfusion using these blood pumps can be applied in infants and young children.