59 year old Caucasian male presents with 3–4 days of encephalopathy. He has a past medical history of celiac sprue, hypertension, asthma, and GERD with history of recurrent encephalopathy for the past 3 years with consistently elevated ammonia levels despite lactulose therapy. He was complaint with a gluten free diet. He has had a complete neurological workup including MRI/CT of brain that showed mild degenerative changes and an EEG that showed generalized slowing of waves not consistent with his symptoms. Hepatic workup for elevated serum ammonia included liver biopsy and an ERCP that was unremarkable. A mesenteric angiogram with transhepatic portagraphy displayed a portal vein to inferior vena caval shunt as a cause of his elevated ammonia levels. Hepatic Encephalopathy is neuro-psychiatric syndrome caused by liver disease. It occurs most often in patients with cirrhosis but is also seen in acute hepatic failure.[1] Liver failure and portasystemic shunting of blood are two important factors underlying hepatic encephalopathy.[1] Portasystemic shunts are of two major types spontaneous and surgical.[1] Surgical porto-caval shunts have been widely used in the treatment of Cirrhosis and recurrent variceal bleeding, however little is known about the congenital formation of these anomalies. Congenital intrahepatic portal-systemic venous shunt is defined as a communication between the portal and the systemic-venous circulation, measuring more than 1 mm in diameter and at least partially located inside the liver.[3] It is a very rare condition with uncertain etiopathogenesis.[3] There are 5 different types. Type I (intrahepatic type) designates cases in which shunts are located between the portal and systemic veins. Type II designates a type of intra/extrahepatic shunt that originates from the umbilical part of the portal vein and serpentines in the liver, then leaves the liver. Type III (extrahepatic type) occurs most frequently. Type IV (extrahepatic) is accompanied by shunts similar to those in type III, but hepatic pathology presents as idiopathic portal hypertension. Type V (extrahepatic) represents the congenital absence of the portal vein, where the superior mesenteric vein joins the intrahepatic inferior vena cava or the left renal vein.[2] Only 47 cases have been reported in the entire French and English literature.[3]