An Unusual Duodenal Mass with GI Bleeding: Gastroduodenal Artery Pseudoaneurysm

Abstract

Purpose: Pseudoaneurysm of the gastroduodenal artery is a rare and potentially lethal complication of chronic pancreatitis. A 44 yo man with a history of chronic alcoholic pancreatitis complicated by pseudocysts of the pancreatic head (4 × 5 cm and 2.5 × 2 cm) presented with a 2 week history of fatigue and black stools. Physical examination revealed pallor, normal vital signs and cardiopulmonary examination, and abdominal tenderness in the epigastrium. Laboratory tests showed Hg 4.1 g/dL, others were normal. EGD demonstrated mild esophagitis, 2 small antral ulcers without stigmata of hemorrhage, and an area of edematous and erythematous mucosa in the duodenal bulb. There were no varices and urease test was negative. Colonoscopy was normal. The patient was transfused, treated with PPI and discharged. Two weeks later he was re-admitted with the same symptoms. Laboratory evaluation showed Hg 6.9 g/dL, lipase 2,472 U/L. EGD revealed normal esophagus, mild antral erythema and a 2 cm friable mass in the duodenal bulb with mild oozing from its surface. Biopsy was obtained and oozing was successfully treated with injection of epinephrine. CT scan, ordered for further evaluation, demonstrated near complete resolution of the pancreatic pseudocysts but discovered a 1.7 × 1.9 × 1.2 cm gastroduodenal artery pseudoaneurysm (PA). Coil embolization of the PA was performed successfully. Splanchnic aneurysms and PAs are seen in 10% of autopsy studies; however, they remain asymptomatic in most individuals. In pancreatitis, splanchnic aneurysms form from enzymatic injury to the vascular wall, often within a pseudocyst. A PA develops when the wall of the aneurysm further enzymatically erodes and ruptures into the pseudocyst. Most cases involve the splenic (30-50%) or gastroduodenal (10-15%) artery. Occasionally a PA may erode into adjacent structures or other vessels. When a patient with PA presents with hemorrhage mortality reaches 50%. When suspected, the presence of PA is confirmed by IV contrast enhanced CT and/or angiogram. Therapy by percutaneous transcatheter arterial embolization or vascular stenting are treatments of choice. Surgery is reserved for complicated cases when endovascular intervention is unsuccessful. Splanchnic PAs are rare but important causes of GI bleeding in patients with acute and chronic pancreatitis. This potentially lethal complication should be considered in the differential diagnosis when treating a patient with GI bleeding and a history of chronic or acute pancreatitis. Caution should be taken during endoscopic evaluation in these cases, as the presence of a mass may be a manifestation of a PA and acute hemorrhage could be provoked by endoscopic manipulations.