Studies on the isolated perfused pig liver

Abstract

Abstract Eighty perfusions of the isolated pig liver were performed using diluted pig blood. Although a high proportion of these perfusions were successful, there was sporadic filure of perfusion, usually manifested by rising hepatic arterial blood-pressure and decreasing total hepatic blood-flow. The success rate of perfusion was improved by addition of low-molecular-weight dextran to the perfusate, the use of a less soluble siliconizing agent for the perfusion apparatus, and the use of new tubing for each perfusion. Preliminary flushing of the liver with Ringer-lactate reduced the success rate and, in unsuccessful perfusions, vaso-active drugs were ineffective in reducing raised vascular resistance. Changes in the perfusate electrolyte, glucose, and enzyme patterns were sometimes observed but could not be related to perfusion success. Perfused livers synthesized urea and bilirubin and incorporated 75Se-labelled methionine into protein. Perfused livers also conjugated bromsulphthalein (B.S.P.), but in unsuccessful perfusions the uptake of the dye from the perfusate was reduced and there was marked entry of conjugated B.S.P. into the perfusate. Careful attention to the details of perfusate composition and perfusion conditions does increase the number of successful perfusions. Suggestions for further improvements are discussed. The technical innovations suggested by these investigations are probably relevant to the preservation of the liver prior to clinical transplantation or to the preparation and perfusion of the porcine liver in the treatment of patients with acute liver failure.