僧帽弁位Björk-Shiley弁置換術後遠隔期の大動脈弁狭窄症に対する大動脈弁置換術の1例

Aortic Valve Replacement 36 Years after the First Mitral Valve Replacement with Björk-Shiley Prosthetic Valve；Report of a Case

はじめに　Björk-Shiley弁は機械弁であるものの経年変化に伴う劣化から弁破損の報告が散見されており，術中の取扱いに関しては注意を要する1～3）．われわれは僧帽弁位Björk-Shiley弁置換術後36年目に大動脈弁狭窄症に対して大動脈弁置換術を施行した症例を経験したので報告する．

A 67-year-old woman was admitted with exertional dyspnea. She had undergone mitral valve replacement with Björk-Shiley prosthetic valve （convexo-concave type） 36 years previously for stenosis and regurgitation in another institute. An echocardiography showed a severe degree of aortic stenosis, and the implanted mitral valve function is normal. We performed aortic valve replacement with a bioprosthetic valve and no prophylactic reoperation for the implanted mitral valve. The postoperative courses were uneventful. The patient was discharged from the hospital in good clinical condition. Postoperative echocardiography showed the prosthetic valves were normal. The close follow-up should be needed to prevent fatal valve dysfunction.