True Ulnar Artery Aneurysm in the Proximal Forearm: Case Report and Literature Review

Ulnar artery aneurysms are rare with less than 150 previously reported. Previously ulnar aneurysms have been most commonly noted as occurring in the distal ulnar artery close to the palmar arch.

We present the case of a 47-year-old male with a background history of human immunodeficiency virus (HIV) who attended our outpatient clinic with symptoms of distal embolization from a proximal ulnar artery aneurysm.

Preoperatively, the aneurysm was thought to arise from the distal brachial artery, and only intraoperatively was the diagnosis of ulnar aneurysm made. The aneurysm was excised, and a reverse vein bypass graft anastomosed end to side on the brachial artery, and end to end on the distal ulnar. True ulnar artery aneurysms also involving the more proximal ulnar artery have been previously reported associated with vasculitic disorders. HIV has been previously associated with aneurysm formation in a number of anatomical locations. This case is noteworthy as it reports on the presentation and successful operative management of a true ulnar artery aneurysm arising in the proximal forearm in the setting of HIV, which has not been previously reported in medical literature.

We present successful operative management of a true ulnar aneurysm in the proximal forearm using a reverse venous interposition bypass. Diagnosis of a proximal ulnar artery aneurysm may represent a diagnostic challenge given its rarity as it may mimic brachial artery aneurysm.