Post-traumatic aneurysms of the thoracic aorta.

Traumatic rupture of the sub-advential tunics (intima, media) of the thoracic aorta is rarely observed in the chronic phase (5 % of survivors). Organisation of the lesion with thickening and ballooning of the adventitia results in post-traumatic aneurysmal formation of the thoracic aorta, situated at the aortic isthmus in the large majority of cases. The diagnosis is usually a chance finding on chest X-ray several years later. CT scan, but mostly MRI and angiography confirm the diagnosis. Their natural history is the same as that of dystrophic and atheromatous aneurysms and dominated by the risk of rupture. The surgical indication should therefore be considered systematically as the treatment is well established and the postoperative prognosis in excellent (mortality rate of 0 to 2 %. Treatment consists in implanting a Dacron tubular prosthesis and, when possible, resection and direct suture.