[Redo-operation for the cusp perforation 5 years after aortic valve replacement with stentless bioprosthesis; report of a case].

: A 31-year-old male presented with increase of aortic valve regurgitation 5 years after implantation of Prima Plus Stentless bioprosthesis in a bicuspid aortic valve. He underwent redo aortic valve replacement with a mechanical valve concomitant with replacement of the ascending aorta. Pathological examination of the explanted stentless valve presented no inflammatory cell infiltration. The prosthetic valve regurgitation was considered to be due to small injury at the 1st operation.