Fascia lata valves: a clinicopathological study.

Sixteen frame-mounted fascia lata valves removed from the mitral, aortic or--in one patient--pulmonary position have been detailed histologically. These valves had remained in 15 patients (11 men and four women) for periods varying between 10 and 44 months. The reason for the original transplantation was either chronic rheumatic endocarditis or calcific aortic disease. In the mitral position, the leaflet in position nearest the site of the original anterior mitral valve cusp showed the least changes. The remaining two leaflets of the fascia lata valve in the mitral position, as well as those removed from the aortic or pulmonary position, showed more severe changes; these consisted of degeneration of collagen tissue and often a severe decrease of nuclei belonging to the fibroblastic series. These changes, as well as superimposition of fibrin or fibrous tissue, tended to become more pronounced the longer the valve had remained in the patient. Viability studies in valves removed from two patients have also been undertaken showing very greatly reduced activity. The possible causes for valve dysfunction have been reviewed, and the findings in this study suggest that contraction of fibrous tissue, which sandwiches the fascia lata valve cusps, may contribute to failure of satisfactory valve function. It is concluded that fascia lata forms a poor substitute for replacement of diseased cardiac valves.