Barbolini G. Calcification of the Aortic Valve: the Arrival Point of a Complex Degenerative Process. JCvD

The histology of the calcified aortic valve has been sequentially revisited in the light of modern concepts of cardiovascular pathology. Fifteen cases of calcified aortic valves, surgically removed for an acquired steno-insufficiency, have been investigated by histochemistry (Weigert’s stain, Van Gieson’s stain, Verhoeff’s stain, Alcian blue / PAS stain). Following the lipidic infiltration of the endothelium, a diffuse proteolytic phenomenon, mainly related to aging, gives rise to tissue degeneration. The subsequent remodelling attempt is ineffective to maintain the valve function, as demonstrated by the limited presence of newly formed muscle-like cells. The arrival point of this degenerative process is represented by a marked calcification, involving the aortic leaflets and the annulus. Proteolysis, absence of an effective remodelling mechanism and calcification are so the fundamental sequential steps of the acquired aortic steno-insufficiency. At the basis of this complex pathological cascade of events, genetic and metabolic disorders play an important role. The conventional histological techniques permit to easily distinguish calcification of the aortic valve from endocarditis and rheumatic lesions and they allow to demonstrate pathogenetic mechanisms in common with thoracic aortic