[Prosthetic valve re-replacement one year after the surgery using a mosaic bioprosthesis].

A 69-year-old man underwent aortic valve replacement with a 21 mm-Mosaic bioprosthetic valve for the treatment of aortic valve stenosis and resulting syncope. One year after the 1st operation, syncope recurred. Echocardiography showed non-symmetrical enlargement( ASH) of the ventricular septum as well as turbulence and increase of the pressure gradient in the left ventricular outlet. Prosthetic valve dysfunction was diagnosed. At the 2nd operation, tears on 2 coronary cusps of the bioprosthetic valve and a subvalvular overgrown pannus were revealed. Aortic valve re-replacement with a 19 mm-SJM Regent valve and the Morrow operation were performed. On analysis of the explanted bioprothesis, distortion of the valvular stent was found. We speculated that distortion of the bioprosthetic stent due to ASH caused the contact of the stent-post and the valvular leaflets, and 2 tears of the leaflets occurred. Pannus formation was thought to have resulted from the fast turbulence caused by ASH and the distortion of the stent.