2452 Intrahepatic Portosystemic Venous Shunt: A Clinically Significant Rare Anomaly

Abstract

INTRODUCTION: Intrahepatic Portosystemic Venous Shunts (IPSVS) are rare vascular malformations between the hepatic and portal veins. Most of the porto-venous shunts are asymptomatic and found incidentally on radiology imaging. These can be either congenital or acquired. Acquired shunts are typically less than 2 mm in size. Occasionally, complications such as encephalopathy, heart failure, pulmonary hypertension and elevated ammonia levels can occur. We report a case of incidental IPSVS in a patient who presented with complaints of fatigue and failure to thrive. CASE DESCRIPTION/METHODS: 82-year-old African American male with hypertension, diabetes mellitus and prostate cancer (treated) presented with complaints of fatigue and loss of appetite for one-month. Laboratory work up showed a hemoglobin of 11.6 g/dl, normal platelet count, and elevated aspartate aminotransferase of 45 U/L and decreased albumin of 2.0 g/dl. Serum ammonia level was normal. He was immune to hepatitis A, non immune to hepatitis B and hepatitis C antibody was negative. A computed tomography scan of the abdomen showed a contrast enhanced tubular shaped vascular connection between middle hepatic vein and the anterior branch of the right portal vein. The size of the shunt was approximately 10 mm (Figure 1). Liver appeared normal except for small calcifications within the parenchyma. Ultrasound Doppler of hepatic and portal veins were performed, and the porto-hepatic shunt was visualized (Figure 2). Patient had a complicated hospital course secondary to sepsis; however, he did not develop hyperammonemia or hepatic encephalopathy during the hospital stay. DISCUSSION: IPSVS in our patient was likely a congenital anomaly given the presentation, size and lack of related symptoms. IPSVS is divided into 4 types; Type 1- Shunt between portal vein and IVC; Type 2- connections between peripheral branches of portal and hepatic veins in one hepatic segment; Type 3- Aneurysmal connection between portal and hepatic vein; Type 4- multiple communications of portal and hepatic veins in both major lobes of the liver. Doppler sonogram with pulse doppler is highly sensitive and specific to evaluate for IPSVS. In symptomatic IPSVS, shunt closure has shown improvement in symptoms and correction of hyperammonemia. Clinicians should consider this rare vascular malformation in patients presenting with hepatic encephalopathy or hyperammonemia in the absence of cirrhosis where shunt closure can be curative.