Blood flow during obstruction to the venous effect of portacaval transposition on hepatic outflow from the canine liver.

When portacaval transposition (PCT) was performed in dogs in combination with a complete hepatic venous outflow block (COB) procedure, estimated hepatic blood flow (EHBF) declined steadily. Four weeks after this combined procedure mean flow was only 46% of the value obtained 3 days after operation, but this did not prevent the development of ascites which occurs in dogs with COB alone. Complete reversal of portal flow was demonstrated in the longest surviving dog. When PCT was performed in dogs with established partial outflow block EHBF remained at preoperative levels whether portal hypertension was present or not prior to the second operation. This maintenance of hepatic blood flow was due to continuing venous flow into the portal bed. It would appear that PCT is probably of little value as a treatment for portal hypertension and bleeding oesophageal varices in cases of advanced cirrhosis, but may be of some benefit in a few selected cases where the hepatic lesion is less severe.