THE ISOLATED-PERFUSED PORCINE LIVER - ASSESSMENT OF VIABILITY DURING AND AFTER 6 HOURS OF PERFUSION

Isolated liver perfusion was developed for the study of liver physiolo gy and preservation. The recent development of new perfusion devices a nd appropriate liver preservation solutions prompted us to reconsider liver perfusion for the specific purpose of evaluating viability in te rms of biochemical changes, paying special attention to modifications in the histological ultrastructure. Twenty-two isolated pig livers wer e perfused with autologous blood. Arterio-portal perfusions were carri ed out using an extracorporeal perfusion circuit with a hollow fibre m embrane oxygenator. Four groups of pig livers were studied using three different liver flushing solutions [Ringer's lactate, ELOHES, and Uni versity of Wisconsin (UW)] and two different oxygenation modalities. L iver function tests and histological studies were done. Our results re vealed that a high partial oxygen pressure (PO2) level was deleterious to the ultrastructural elements of hepatocytes, in particular to the mitochondria. It was also associated with deficient metabolic performa nce, i.e., poor bile production and lack of aerobic metabolism. Normal blood gas values could be obtained with the use of air for liver oxyg enation. Flushing of the liver with Ringer's lactate or a macromolecul ar solution such as ELOHES was associated with severe liver cell injur ies, as reflected by a marked rise in liver enzymes and histological l esions. Satisfactory results were obtained when UW solution was used f or liver harvesting. We conclude that an appropriate liver preservatio n solution, normal blood gas values, and normal physiological arterio- portal pressure and blood flow are essential for appropriate liver fun ction with preservation of liver architecture and of hepatocyte ultras tructures. Total bilirubin in bile and Factor V are sensitive indicato rs of good liver function.