An Unusual Cause of Portal Hypertension

Abstract

52 year old male with a history of lymphoma and prior chemotherapy (4 yrs ago)presented with new onset ascites. He also had splenectomy as part of staging for lymphoma. Physical exam revealed moderate ascites, jugular venous distension, bilateral lower extremity edema and hemocult positive stool. Liver Function tests: serum albumin 4.2gm/dl ALT 34 I U/L, AST 36 IU/L, total bilirubin 1.1 mg/dl. Serum creatinine and electrolytes were normal. Bone marrow was normal with no recurrence of lymphoma. Ascitic fluid showed albumin of 2.3 mg/dl, with negative cytology. Ascitic fluid LDH, amylase and bilrubin were normal. Ascites with a serum albumin ascitic fluid gradient (SAAG) greater than 1.1, led to the following investigations for the etiology of portal hypertension (Portal HTN). Doppler ultrasound of the liver showed dilated main portal vein with forward flow in the right and left branches. Hepatic veins were patent with appropriate wave forms. A triple phase CT scan showed prominent portal vein. Echocardiogram showed normal left ventricular function and normal sized chambers. Estimated PA pressure was 25 mm Hg. Upper endoscopy was significant for portal gastropathy with no esophageal or gastric varices. A transjuguar liver biopsy showed normal hepatic histology. Trichrome and reticulin stains showed absence of fibrosis with normal architecture. Pressure measurements obtained at the time of liver biopsy were as follows: Suprahepatic inferior venacava 4 mmHg, free hepatic vein 6 mmHg and wedge pressure 14mmHg. Hence this patient had clinical manifestations of portal hypertension such as ascites, dilated portal vein and high SAAG, but lacked any specific explanation as he had normal liver biopsy and a normal gradient across the hepatic vein and the sinusoids. Because of the prior history of splenectomy and lack of any other specific etiology we performed a celiac axis angiogram. This showed a splenic artery and venous fistula, near the site of ligation of splenic artery. The fistula was succesfully embolized with resolution of patient's ascites. Splenic arterovenous fistulas (SAVF) are extremely uncommon causes of portal HTN. Most often patients present with gastrointestinal bleeding. History of splenectomy and normal gradient across the hepatic vein and the sinusoids prompted us to do an angiogram. It is important to diagnose this entity as prolonged exposure to high flow in portal vein can ultimately lead to portal fibrosis and cirrhosis.