THE HEPATIC artery contributes about 20% of hepatic blood flow, while the portal vein carries the remaining 80%. There is some collateral supply, but under normal conditions this is negligible. Reciprocal variations in the amount of blood carried by either the hepatic artery or the portal vein occur, and Soskin and co-workers1 have observed that this reciprocal variation could be as low as 10% or as high as 90% in either vessel.
Some interesting observations have been made when the liver is supplied by either one of these vessels, the other being tied. Ligation of the portal vein, as in Eck fistula, results in parenchymal fibrosis and considerable reduction in the size of the liver. The dogs, however, do not die, and there is little or no alteration in hepatic function.2 Ligation of all the branches of the hepatic artery is followed in about 100% of cases by