True ulnar artery aneurysm of the hand in an 18-month-old boy: a case report.

True aneurysms of the hand arteries are rare and are exceedingly uncommon in children. Presented is a case of a true ulnar artery aneurysm in an 18-month-old boy in which there was no history of trauma. The aneurysm was resected without reconstruction because of the normal preoperative Allen test result, normal preoperative finger pressure measurement with ulnar artery occlusion, the angiographic evidence that the radial artery was the dominant artery of the hand, and intraoperative evidence of adequate hand perfusion after excluding the aneurysm from the hand circulation as documented by good Doppler signals in all digital arteries.