PORTOSYSTEMIC ANASTOMOSES - METABOLISM AN D CLINICAL IMPLICATION

The effects of portosystemic shunts on both the metabolism and mental function differ from the respective events caused by parenchymal liver failure. Animal experiments as well as studies on patients with idiop athic portal hypertension have shown that portalsystemic collaterals i nduce marked hyperammonemia, hyperglucagonemia and a lowering of branc hed-chain amino acid plasma levels. They do not result in overt enceph alopathy, even though there are neurophysiological alterations. In str ingently selected cirrhotic patients undergoing a surgical portacaval anastomosis (n = 11), we obtained metabolic findings very similar to t he experimental observations; a deterioration in mental function did n ot occur. Placement of transjugular intrahepatic portosystemic shunt ( n = 19) gave rise to pronounced hyperammonemia but was, apart from thi s, characterized by specific metabolic deviations, e. g. a considerabl e reduction in glucose tolerance.