Hepatic encephalopathy secondary to a large-caliber porto-hepatic venous shunt. A case report.

A case of hepatic encephalopathy secondary to a large-caliber porto-hepatic venous shunt in a 61-year-old woman with gastric cancer is reported. Mild confusion, flapping tremor and hyperammonemia were noted preoperatively. Abdominal ultrasonography showed a large-caliber porto-hepatic venous shunt in the left lateral segment of the liver. Percutaneous transhepatic portography and superior mesenteric angiography were confirmatory. Intraoperative portal scintigraphy was performed before and after temporary shunt occlusion to measure the intrahepatic shunt rate, which decreased markedly after occlusion. Portal pressure was also measured, and increased only slightly after occlusion. Left lateral hepatic segmentectomy, and subtotal gastrectomy with splenectomy were performed. Hepatic encephalopathy resolved postoperatively. The shunt was thought to be acquired. The relevant reports on large-caliber porto-hepatic venous shunts in the literature are reviewed.