Chronic portal-systemic encephalopathy with normal portal vein pressure possibly due to noncirrhotic portal fibrosis.

This is the report of a 50-year-old man with a more than 20-year history of chronic progressive portal-systemic encephalopathy. Liver tests were normal except for increased serum ammonia and indocyanine green plasma retention. The liver pathology was compatible with idiopathic portal hypertension or noncirrhotic portal fibrosis, demonstrating localized surface nodularity and portal fibrosis. Percutaneous transhepatic catheterization of the portal vein revealed near top normal portal vein pressure and a large shunt connecting the left gastric or superior mesenteric vein and the left renal vein. Presumably, the patient had portal hypertension in the past and formation of a short, large-caliber shunt between the portal system and the renal vein effectively decompressed the portal circulation.