[Pathology of degenerative aortic valve insufficiency]

The authors studies 154 cases of degenerative aortic regurgitation which presented macroscopically with atrophic changes of the valve and sometimes with hypertrophy and calcification. Histologically, the essential abnormality was the finding of mucopolysaccharide deposits dissociating the corpus spongiosa from the corpus fibrosa. Depending on the importance of these lesions, three degrees of severity can be defined, the most extensive (84% of our patient population) appearing to be typical of the disease. In addition, mild mitral valve prolapse (5%) and medial necrosis of the aortic wall (80% of patients undergoing aortic biopsy) were observed. These morphological features are on the whole quite different to those of other aortic valve pathologies (rheumatic, endocarditis). However, the border line with other pathologies with a similar anatomopathological substratum is less clearly defined: genetic abnormalities (Marfan's syndrome, Lobstein's disease, etc...) or age-related degenerative disease. The pathogenesis is not clearly understood but could be related to regional disturbances in collagen metabolism with collagenolysis predominating.