Brachial Artery Pseudoaneurysm as a Complication of Osteochondral Exostosis of the Humerus in Computed Tomography Angiography Images.

We present computed tomography angiography images of a rare pseudoaneurysm of the left brachial artery, a complication of idiopathic injury to the artery caused by an osteochondral exostosis of the left humerus. A 22-year-old Caucasian man with no significant medical history was admitted to the emergency department due to sudden, intense pain in his left arm, numbness, and pallor of his left forearm and hand. The patient's consulting vascular surgeon referred him to the computed tomography (CT) laboratory for a computed tomography angiography (CTA) of the arteries of his left upper limb. In the CTA examination, at the level of the proximal segment of the left brachial artery, an excess of contrast was visualized, measuring up to approximately 1.5 × 1.2 cm in cross-sections and up to approximately 0.7 cm in the craniocaudal dimension. The CTA image was suggestive of a pseudoaneurysm of the left brachial artery. Laterally, the pseudoaneurysm was adjacent to the apex of the imaged osteochondral exostosis on the medial surface of the proximal shaft of the left humerus. A surgical procedure was performed to repair the pseudoaneurysm of the left brachial artery, including removal of the bony exostosis of the left humerus. In summary, relatively common, benign bone lesions can occasionally result in serious vascular complications. CTA is the gold standard for diagnosing these complications.