patients less than 60 to 65 years is a mechanical valve.10,26 For a 65-year-old patient, structural valve deterioration of a tissue valve will occur, on average, 10 to 15 years after implantation while the patient???s life expectancy is only 11.3 years.10,36 Thus, a patient choosing to undergo a prosthetic valve replacement at 65 years will have a 28% chance of needing a reoperation.10 As tissue v