S4780 A Case of Fistula Formation Between Pseudoaneurysm of Hepatic Artery and Duodenum: A Rare Cause of Upper Gastrointestinal Bleeding (UGIB)

Introduction: Hepatic artery aneurysms (HAAs) represent approximately 20% of all visceral aneurysms. Common causes include trauma, atherosclerosis, and medial degeneration. The majority of patients are asymptomatic before rupture and rupture is the first clinical manifestation in most cases. Rarely, upper gastrointestinal bleeding (UGIB) results from fistula formation between the hepatic artery and duodenum. Case Description/Methods: A 20-year-old man with a history of blunt abdominal trauma 3 years ago was admitted to the medical ward with complaints of right upper quadrant abdominal pain, melena, and hematemesis. Physical exam was remarkable for pallor and tachycardia except for anemia (hemoglobin: 6.6 g/dl), laboratory findings were unremarkable, including liver function tests (LFTs). Hepatitis and human immunodeficiency virus (HIV) screening were negative. Abdominal ultrasound revealed a pulsatile mass of 58 mm in diameter in the porta hepatis, and colour doppler showed bidirectional flow. A contrast-enhanced computed tomogram of the abdomen showed a 90 mm × 50 mm mass in the porta hepatis signifying hepatic artery pseudoaneurysm (HAP), and tiny air density foci were noted in the pseudoaneurysm signifying aneurysm-duodenal fistula. A computed tomography Angiogram revealed an accessory hepatic artery arising from the proximal superior mesenteric artery as a feeding artery. An Upper GI endoscopy revealed a torrential amount of bile flowing from the ampulla of Vater, and an indentation was visualized on the medial wall of the second part of the duodenum. Patient underwent laparoscopic clipping of the feeding artery, and postoperative doppler studies confirmed the reduction in the size of the aneurysm as well as the absence of pulsatile flow through the aneurysm. The postoperative course was uneventful, and at 1-year follow-up, the patient was asymptomatic. Discussion: HAAs, though rare, are a recognized cause of UGIB, accounting for 0.4% of cases, 20% of which are pseudoaneurysms. With a rupture risk of 21%-80% and an associated mortality of 21%-43%, early intervention is critical. HAPs can form fistulas with the duodenum, leading to UGIB. Definitive treatment depends upon the surgical ligation and aneurysmectomy with bypass grafting or with end-to-end anastomosis. In our patient, given the pseudoaneurysm’s size, robust hepatic collateral supply, and the patient’s low surgical risk, surgical ligation was performed.