A Case of Superior Mesenteric Artery Aneurysm Mimicking an Abdominal Aortic Aneurysm and Presenting as a Pulsating Abdominal Mass.

A 62-year-old male with a smoking history of 30 pack-years presented with a 1-year history of a periumbilical pulsating mass. He had been treated for hypertension for 2 years. Physical examination revealed a huge pulsating mass in the periumbilical abdomen. Femoral and popliteal arterial pulses were palpable. Computed tomography showed arterial dissection in the proximal segment of the superior mesenteric artery, a huge aneurysm (52×50 mm) with mural thrombus and two smaller aneurysms (20×20 mm) in the right ileocolic and ileal branches, along with atherosclerotic changes. Interposition using the great saphenous vein was performed after aneurysmal isolation and ligation of jejunal branches in the sac. Distal flow was reestablished by end-to-end and end-to-side anastomoses of the right ileocolic and ileal branches, respectively. No complications were observed at 1-year follow-up.