Traumatic pseudoaneurysms of the thoracic aorta. Anatomic and radiologic correlations.

Long-term survivors with traumatic ruptures of the aorta that are not detected at the time of injury manifest pseudoaneurysms. We reviewed a ten-year experience with pseudoaneurysms of the thoracic aorta to correlate anatomic and roentgenographic findings in this unusual group of patients. Eleven patients, who were 28 to 65 years of age, had abnormal chest findings one to 36 years after their injuries. Nine patients had calcification that was visible on the plain chest film, and two patients had calcification that was visible on computed tomography. Nine of the 11 pseudoaneurysms, all of which were distal to the left subclavian artery, were saccular and involved only the medial aspect of the aortic wall. Anatomically, they appeared to have been confined in a space bordered by the mediastinal pleura, pulmonary artery, left mainstem bronchus, and normal aorta. Pseudoaneurysms that occur on the medial aortic wall at the level of the ligamentum arteriosum may be more stable because of anatomic confinement by stable adjacent structures.