Compensatory increase of hepatic artery blood flow follows protosystemic shunt surgery. Parathormone stimulates significantly blood circulation through the hepatic artery. This stimulating effect is used to test vasodilative capability of the hepatic artery prior to shunt surgery. We report our findings on a additional increase of the hepatic artery blood flow under Parathormone. A portal-caval end-to-lateral shunt surgery caused an increase in blood flow 71 percent on an average compared to the basic value. After administration of Parathormone we observed an additional increase of 13,5 percent. This result indicates, that the hepatic artery will be dilated by Parathormone after a portocaval shunt too.