Superficial ulnar artery pseudoaneurysm.

The ulnar artery is the larger terminal branch of the brachial artery. It originates in the cubital fossa and is covered by the flexor muscles of the forearm. We report an anatomic variant in which the ulnar artery was in a superficial position in the forearm. Since this variant was unknown, an attempted venous puncture injured the artery, causing formation of a pseudoaneurysm.