Pathology of chronic rheumatic mitral valvulitis in Iran and its surgical implications.

Sixty-two consecutive surgically removed chronic rheumatic mitral valves were classified and tabulated according to their pathological features in relation to age and sex of the patients. The pathological features of the valves are quite different from the cases seen in Western hemisphere. Three types of gross pathological features are described. First is fibrous stenotic type which has very thick cusps and extremely short chordae tendineae. It is the most frequent rheumatic vavle seen in children, and majority of the valves show pure stenosis, for which probably open commissurotomy is the procedure of choice. Those which have a combination of stenosis and insufficiency usually require valve replacement. The second is the elastic insufficient type, which has a unique gross pathological feature, consisting of a remarkable elasticity and moderately thickened cusps. A valve replacement or valve repair when feasible is the treatment of choice for this type. The third is the calcific stenotic type. In this type the cusps are moderately thickened with short chordae tendineae with various degrees of calcification. This type is seen usually in the 4th decades of life and is more frequent in males. This type of valve must be treated either by open commissurotomy in order to eliminate the risk of embolization of calcific material or with valve replacement.