Dystrophic aortic insufficiencies represent at present time an important etiology of operated on pure and voluminous aortic regurgitations (n = 95, i.e. 28.1% of cases followed by our working team). The valvular dysplasic lesions by which they are characterized were associated in 2 out of 3 cases with parietal lesions of the ascending aorta: annulo-ectasic disease (n = 42) or important non-aneurysmal dilatation of the ascending aorta (n = 20). However, these valvular dysplasias may also appear isolated in an aorta morphologically normal at peroperative examination (n = 33). Among the 42 patients suffering from, annulo-ectasic disease (group 1) the type of surgical correction varied with the period of operation. Valvular replacement isolated (n = 3, group 1 a) or associated with aortic supracoronary surgery (n = 17, group 1b) were the procedures before 1978. Since then, 22 patients (group 1c) had a total replacement of the ascending aorta were subjected to valvular interventions (19 replacements, 1 valvuloplasty). When performed, parietal biopsy of the aorta showed in 11 out of 15 cases signs of cystic medio-necrosis. After a delay of 53 +/- 40 months, 11 out of 20 patients of group 1a and 1b died, 5 of them from the evolution of lesions at the ascending aorta (3 ruptures and 2 dissections); one patient was reoperated 12 years after the placing of a supracoronary tube, because of the development of a voluminous aneurysm of the sinuses of Valvalva which initially were only simply dilated.(ABSTRACT TRUNCATED AT 250 WORDS)