The operative treatment for symptomatic mitral stenosis is now generally accepted. It may be undertaken with low risk and excellent results. Acquired mitral insufficiency, aortic stenosis, and aortic insufficiency are frequently treated during open heart surgery by corrective procedures designed to improve valve function. These techniques, however, are carried out with a significant mortality risk and, although the improvement obtained may extend over a considerable period of time, the results are considered palliative. Retention of valve structures composed of living tissue is desirable when consistent with good function. When both the aortic and mitral valves are diseased and incompetent, the cardiac status is generally considered beyond the scope of present surgical methods1 In the treatment of defective valves, total mechanical correction is the ultimate aim of the surgeon. This will be achieved in the presence of severe defects when durable prosthetic valves can be firmly implanted with reasonable safety.