A 28 year-old male who had received Konno procedure twelve years ago with 23mmmechanical aortic valve and bovine pericardium with which his small aortic annulus, ventricular septum and right ventricular outflow tract had been enlarged was transferred due to sudden congestive heart failure. There were perforations on aortic and interventricular portion of bovine pericardial patch above and below the aortic valve, respectively, which was calcified and denaturated severely. The perforations seemed to be attributed to the cracks, resulting from mobility of mechanical aortic valvc itself and stiffness of calcified and denaturated bovine patch. We performed a redo Konno procedure applying PTFE patch.