[Aortic insufficiency and degenerative aortic disease. Anatomic study and etiology]

Degenerative (or dystrophic) artery disease is the most recently recognized etiology of aortic regurgitation (AR) and has been observed since the sixties. This condition concerns about one third of the pure AR cases, which now undergo surgery and involves two populations (with a marked predominance of men): subjects over 50 years of age, with no special history, and some post-adolescent patients suffering from Marfan's disease. The anatomical lesions are identical in three respects: the ascending aorta, with a spindle-like aneurysm, thin or slack, collapsed aortic sigmoids, dilated aortic ring. The histopathologic observations involve two features, the relative importance of which varies from one case to another: a loss of elastin and collagen fibers (the main cause of the disease) and an accumulation of acidic mucopolysaccharides (known as mucoid or myxoid degeneration) which involves some reaction to hemodynamic turbulence and is somewhat secondary to fragilization of the aorta or sigmoid wall. Rupture of the aorta wall, which is restricted to the inner two thirds of the media or complicated by a dissecting hematoma, may aggravate both the distention of the ascending aorta and the AR. One hundred of the 150 cases of pure AR which underwent surgery at Lyon (France) during 1986 and 1987 belonged to this dystrophic etiologic category and called for a special procedure (Bentall).