Arterioportal fistula requiring liver transplantation

Abstract

Arterioportal fistula (APF) is an uncommon cause of portal hypertension. We report a case of APF that first came to clinical attention more than 40 years after the inciting event (a liver biopsy), when the patient developed refractory ascites. A 51-year-old man was diagnosed with Wilson's disease in 1963 (as a child) following a diagnostic liver biopsy. He was treated with penicillamine for the next 43 years without symptoms. He had a “clotted portal vein” in 1995, noted on a liver ultrasound, and his last liver biopsy in 1996 showed no evidence of chronic liver disease. In November 2005, the patient developed refractory ascites, weakness, and shortness of breath. An abdominal ultrasound and computed tomography scan showed a very large APF in the liver parenchyma. The patient underwent a liver biopsy demonstrating nonspecific portal inflammation and mild periportal fibrosis. In addition, a hepatic angiogram and a Doppler ultrasound showed a tortuous right hepatic artery that communicated directly with the portal vein through an APF (Figures 1 and 2). The patient was referred to our facility for further management, shortly after which time he developed a severe gastric variceal bleed. Hepatic arteriogram of an APF. The yellow arrow indicates the hepatic artery. The orange arrow indicates the AFP. The diameter at “1” is 2.4 cm, and the diameter at “2” is 2.7 cm. Doppler ultrasound of an APF. MPV, main portal vein; HA, hepatic artery. The patient underwent 2 percutaneous embolizations of the feeding right hepatic artery that were unsuccessful in occluding the fistula secondary to multiple collaterals. His symptoms of refractory ascites and cachexia remained. He was surgically evaluated and deemed to have a nonresectable APF due to extensive collateralization and was listed for liver transplant. The patient had a lab model for end-stage liver disease (MELD) score of 11. A MELD exception score was requested through the regional review board and the patient was given a MELD match or an exception score of 22. Three months later the patient received a liver transplant, during which he required approximately 100 units of blood. The explanted liver revealed parenchyma with mild chronic inflammation and arterialization of the portal vein with increased smooth muscle in the vessel wall. APF, arterioportal fistula; MELD, model for end-stage liver disease. APF is an uncommon complication after liver biopsy (5.4% 1 month after biopsy).1 When clinical symptoms develop, the most common presentations are gastrointestinal bleeding (27%) and ascites (26%).2 APFs likely develop during a liver biopsy, when a branch of the high-pressure hepatic artery and a branch of the low-pressure portal vein are transected by the biopsy needle. These APFs are small, peripheral, intrahepatic lesions that usually spontaneously thrombose within a month.3 Larger APFs may develop in the central region of the liver with sufficient flow from larger vessels to sustain development of the shunt. In very rare cases, such as with our patient, the fistula may grow in size and become clinically symptomatic with portal hypertension. Consequently, these APFs may require radiological and/or surgical intervention for closure. There are also rare congenital lesions that are usually intrahepatic and diffuse. Liver transplantation as a treatment for APF is very rare. Vauthey et al. reviewed 88 cases of APF in which a case of a cirrhotic patient with jaundice, ascites, encephalopathy, and an APF requiring transplantation was described.2 Another case, published in 1989 and not cited in Vauthey's review, involved a large APF, likely due to biopsy, in a patient without histologic features of cirrhosis requiring liver transplantation.4 In 1998, D'Agostino et al. published a case of a patient with congenital APF requiring transplantation at age 14 after several sessions of embolization and fistula occlusion.5 Most of the documented cases have been successfully treated with radiological procedures and only rarely require surgical intervention. The unusual characteristic of our case was the size of the fistula, severity of symptoms, and requirement of liver transplantation for treatment.