Spontaneous portosystemic shunt: relationship to spontaneous encephalopathy and gastrointestinal hemorrhage.

This study examined the effect of large spontaneous portosystemic shunts on the incidence of variceal hemorrhage and hepatic encephalopathy. Twenty cases of chronic liver disease with large spontaneous shunts were compared with a group of patients with liver disease and with Cruveilhier-Baumgarten (C-B) murmurs and with a control group having liver disease and absence of large shunts on angiography. Gastrointestinal hemorrhage was present in similar proportions of patients in the three groups. Hepatic encephalopathy occurred more frequently in the spontaneous shunt group and C-B murmur group. The encephalopathy was spontaneous in 12 of 14 patients with large natural shunts whereas it was precipitated by events such as gastrointestinal bleeding, diuretics, or infection in 14 of 15 of the patients with C-B murmur and five of the seven controls. Therefore, spontaneous portosystemic shunts do not protect against gastrointestinal hemorrhage and are associated with an increased risk of spontaneous hepatic encephalopathy.