Transection of the thoracic aorta following trauma usually:

A. Is located just distal to the left subclavian artery.

B. Produces a false aneurysm.

C. Is fatal in 80% of cases.

DISCUSSION: Transection of the thoracic aorta may occur at multiple sites from the isthmus down into the abdominal aorta. Transection of the ascending aorta occurs but is uncommon. Those who survive the initial injury and do not rupture into the pleural space do so because the false aneurysm is supported by the adventitia and pleura. The majority of transections occur just distal to the left subclavian and the immediate mortality is about 80%.