The mechanism of postshunt liver failure.

To determine the influence on postoperative hepatic mass, body weight, ammonia clearance, hepatic urea cycle enzyme activity, and hepatic protein metabolism, 59 dogs were divided into six experimental groups: sham operation end-to-side portacaval shunt, mesocaval shunt with subsequent end-to-side portacaval shunt, distal splenorenal shunt, caval left portal shunt, and portal venous seqregation with juglar vein interposition. Compared to total shunt, selective diversion of portal blood from the liver produces less postshunt liver atrophy, less body weight loss, improved maintenance of urea cycle enzyme activity, improved ammonia tolerance, and less decrease in hepatic deoxyribonucleic acid (DNA), ribonucleic acid (RNA), and protein content. Segregation of left from right hepatic lobes, in relationship to portal or systemic venous hepatic perfusion or in relationship to gastroduodenopancreaticosplenic or intestinal portal venous drainage, caused little change in enzyme or protein metabolism in respective hepatic lobes.