[Dystrophic aortic insufficiency: influence of dilatation of the ascending aorta on secondary outcome]. / Insuffisance aortique dystrophique: influence de la dilatation de l'aorte ascendante sur l'évolution secondaire.

This cooperative study recensed 89 cases of patients operated for aortic regurgitation in whom the dystrophic process was confirmed on anatomical (thin, translucent valves without symphysis, multilation or sclerosis) and histological criteria (mucinous infiltration). They included 81 men (91%) and the average age was 52 +/- 14 years. The valvular degeneration was part of a generalised dystrophy of elastic tissue in 8 patients (6 "formes frustes" of Marfan's syndrome, 2 Lobstein's syndrome). The patients were divided into 2 groups according to the diameter of the ascending aorta measured by echocardiography and/or aortography. In Group 1 (n = 40), the aorta was not dilated (diameter less than 40 mm) whereas in Group 2 (n = 49), the diameter of the ascending aorta was dilated (40-55 mm) but not aneurysmal (loss of parallelism of the aortic walls). The two groups were comparable before surgery with respect to age, sex, functional class, degree of left ventricular dilatation, left ventricular ejection fraction and presence of associated coronary disease). There were no differences in the operative parameters but aortic parietal biopsy (n = 35) revealed clear signs of cystic medianecrosis more often in Group 2 than in Group 1 (14/25 versus 1/10, p less than 0.05). No operative procedure was performed on the ascending aorta during aortic valve replacement. One operative death occurred in each group. After an average follow-up of 4 years, there was a higher mortality in Group 2: the actuarial 7 year survival rate being 74% in Group 1 and 54% in Group 2. This was explained by a higher incidence of ascending aortic complications. Only 1 patient in Group 1 developed an aneurysm of the ascending aorta requiring reoperation compared to 14 patients in Group 2, 8 of whom were reoperated (p less than 0.01). These results suggest that non-aneurysmal dilatation of the ascending aorta in patients with dystrophic aortic regurgitation is a poor prognostic factor because of the high incidence of secondary aortic parietal complications (aneurysm, dissection).