Experimental study of liver injury after partial hepatectomy with intermittent or continuous hepatic vascular occlusion. Differences in tolerance to ischemia between normal and cirrhotic livers.

The degree of residual liver injury in normal and cirrhotic rats undergoing 70% hepatectomy with hepatic inflow occlusion was examined. The total duration of clamping was 60 min and animals were divided into 3 groups according to the ischemic modality: a 15-min intermittent clamping group (group I); a 30-min intermittent clamping group (group II), and a 60-min continuous clamping group (group III). In normal liver rats, the survival rates after operation in groups I, II and III were 90, 90 and 30%, respectively, compared to 70, 50 and 38%, respectively, in cirrhotic rats. The serum aspartate aminotransferase (AST) level increased markedly with prolongation of each period of clamping in rats with normal liver, showing higher AST levels than those with cirrhotic liver. The liver tissue adenosine-5'-triphosphate (ATP) levels and energy charge (EC) values decreased with prolongation of each period of clamping. Cirrhotic livers showed lower ATP levels and EC values than normal livers. Although there was no significant difference in the mitochondrial function between normal and cirrhotic livers in the group of the same form of ischemia, phosphorylative efficiency of mitochondria was maintained satisfactorily in normal groups I and II and in the cirrhotic group I. Even though cirrhotic livers showed a smaller necrotic response to ischemia than normal livers, they were more vulnerable to ischemia because of an inability to maintain energy metabolism. Therefore, when performing resection of a cirrhotic liver, a 15-min intermittent clamping method should be adopted.