A patient with a 10-year-old Medtronic Hancock II porcine aortic bioprosthesis developed severe aortic insufficiency. A transesophageal echocardiogram showed a long and mobile mass attached to the bioprosthesis which was consistent with a torn cusp. The patient underwent replacement of the prosthesis with a mechanical valve. Pathological examination showed two subacute tears arising from the same suture buttressing site. These two tears allowed a portion of the valve apparatus to prolapse.