Anatomic and radiologic bases of surgery of the thoracic aorta.

Lesions of the thoracic aorta create problems related to their site and relations with the main aortic branches. The aim of surgery must be to treat the lesion while ensuring perfusion of the tissues excluded by clamping during the operation. Anatomic study of the aortic lesions is based on imaging. Angiography is still often the basic examination though it shows only the lumen and course of the aorta. However, CT and MRI visualise the aortic wall and especially the relations of the aorta to the mediastinal structures. A comparison of anatomic and imaging studies was made on 10 fresh subjects coming from the anatomy department of the Saints-Pères and from the school of surgery of Fer à Moulin. Sections were made every 3 to 5 mm in 3 planes (sagittal, coronal and axial) after CT localisation of the plane of section. This anatomic study was correlated with CT and MR images made on healthy volunteers. The choice of surgical management of a lesion of the thoracic aorta is based on preoperative anatomic assessment by imaging applied not only to the aorta but also to its branches and the territory supplied.