[Pannus Formation Two Years after Bioprosthetic Aortic Valve Implantation;Report of a Case].

We report a case of early deterioration of the bioprosthetic aortic valve 23 months postoperatively. A 77-year-old man who had undergone aortic valve replacement with a 23-mm Epic valve( St. Jude Medical [SJM])presented to us after a syncopal episode. Echocardiography revealed severe aortic stenosis, and redo aortic valve replacement with a 21-mm SJM mechanical valve was performed. All 3 cusps of the tissue valve were thickened by fibrous pannus overgrowth. Neither calcification nor invasion of inflammatory cells was observed. The cause of pannus formation at such an early stage after implantation remains unknown.