Effect of Portacaval Shunt on Gastric Acid Secretion in Dogs with Liver Disease, Portal Hypertension and Massive Ascites

Abstract

To determine the effects on gastric acid secretion of portacaval shunts performed in dogs with liver disease, acid production from Heidenhain pouches was studied continuously during a control phase, a phase of congestive cirrhosis, portal hypertension and ascites produced by ligation of the hepatic veins, a portacaval shunt phase, and a shunt takedown phase. Nine dogs were studied until the time of shunt, 4 of the 9 had post-shunt studies in addition, and one was observed throughout all 4 phases, including the period after takedown of the shunt. Following hepatic vein ligation, all dogs developed morphologic and chemical evidence of severe hepatic damage, portal hypertension which averaged 237 mm. saline, and massive ascites which averaged 5.1 L. Side-to-side portacaval shunt reduced portal pressure to normal levels and relieved the ascites, but did not correct pathologic or functional hepatic abnormalities, which in some animals progressed. Liver disease, portal hypertension and ascites produced a significant depression of gastric acid secretion, similar to that which our previous studies demonstrated. Daily 24-hr, acid production decreased an average of 69%, mean daily 6-hr, post-cibal acid output declined 68%, acid secretory response to histamine tell an average ol 31%, and mean acid secretion following a test meal diminished 74%. Construction of a portacaval anastomosis resulted in an Immediate, marked and highly significant hypersecretion of acid in every dog. Mean daily 24-hr, acid output increased 1,619%, average daily 6-hr, postcibal acid production rose 1,714%, histamine stimulated acid secretion increased an average of 345% , and mean acid secretory response to a test meal was elevated 2,490%. Acid secretion following shunt increased significantly above levels observed in both the ascitic and control phases. Takedown of the portacaval shunt in 1 dog resulted in reappearance of massive ascites and return of gastric secretory depression. Performance of a portacaval shunt in dogs with liver disease, portal hypertension and ascites is followed by striking gastric acid hypersecretion similar to that observed in normal dogs subjected to shunts. Increased acid production is most marked following ingestion of food.