[Malfunction of the Björk-Shiley valve prosthesis due to disc defacement--report of two cases of successful reoperation].

Derlin-disc model Björk-Shiley valve prosthesis was reoperated due to the disc defacement. One had admitted cerebral embolism which was suggested due to the prosthetic valve malfunction of aortic position and the other had congestive heart failure due to the malfunction of mitral position. These patients had implanted Derlin-disc model Björk-Shiley valve prosthesis in the aortic and mitral position 10 and 11 years ago. One's cineangiocardiography showed mild aortic regurgitation and the other showed mitral regurgitation due to the malfunction of the prosthesis. The episode of cerebral embolism in one patient was suggested due to the malfunction of aortic prosthetic valve, and congestive heart failure in the other patient was due to the malfunction of mitral prosthetic valve. These prostheses which removed at the reoperation were observed with strat shape indentation and distinct of the disc which resulted the malfunction of the prostheses. In patient who replaced with Derlin-disc model Björk-Shiley valve prosthesis should be carefully followed up.