A case report of valve dysfunction associated with abrasion of the Delrin disk used in early Björk-Shiley mitral valves requiring resurgery.

A 39-year-old woman had undergone mitral valve replacement (MVR) (29-mm Björk-Shiley Delrin disk) at 6 years of age. Severe mitral regurgitation, aortic regurgitation, and left ventricular dilatation were detected by echocardiography in October 2006, and MVR (ON-X 25 mm) and aortic valve replacements (St. Jude Medical Regent, 21 mm) were performed in December. The Delrin disk of the previous prosthetic valve, located at the position of the mitral valve, was markedly abraded, broadening the clearance from the valve seat. The postoperative course was smooth without complications, and the patient was discharged, walking by herself, on day 19 after surgery. A Delrin disk was used for the tilting valve in early Björk-Shiley valves, but has been replaced by pyrolytic carbon because of problems with durability of the Delrin material. Follow-ups of patients who have undergone procedures using Delrin disks ares necessary, with consideration of valve replacement.