A 22-year course of the Kay-Shiley disc valve with muscle guard at the mitral position.

Almost 33 years have elapsed since the introduction of the Kay-Shiley disc valve in Japan. Following the development of pyrolite carbon, the Kay-Shiley valve is no longer in clinical use. We report the case of a female patient who had had an isolated mitral valve replacement with the Kay-Shiley disc valve with single muscle guard 22 years previously. After numerous thromboembolic episodes with the Kay-Shiley disc valve, a successful reoperation was done with the CarboMedics valve. The explanted valve revealed that the grooved occluder disc had a loosely adherent clot. The thromboembolism is a notorious complication associated with this valve. We recommend re-replacement of the Kay-Shiley valve whenever possible.