Mitral valve replacement: a comparison of two prostheses

Between November, 1965 and June, 1970, 175 patients underwent mitral valve replacement with the Smeloff-Cutter prosthesis (109 patients) or the toroidal valve (66 patients). The early mortality for patients with a toroidal mitral prosthesis was 18.2 percent (12 patients) and the late mortality 34.8 percent (23 patients). Among patients in whom Smeloff-Cutter mitral valves were inserted, the early mortality was 15.6 percent (17 patients) and the late mortality 23.9 percent (26 patients). During a follow-up period extending at least five years, thromboembolic complications occurred in 25.9 percent (14) of patients with toroidal valves and 7.6 percent (7) of patients with Smeloff-Cutter valves. Reoperation was necessary because of thrombosis of the prosthesis in seven patients with toroidal valves and two patients with Smeloff-Cutter valves. The incidence of endocarditis was the same in both groups. In this study, the Smeloff-Cutter mitral prosthesis proved to be superior to the toroidal valve because of a lower incidence of thromboembolism.