The two most common reasons why patients need to replace their aortic valve are (i) blood flow is constricted across a narrowed heart valve (aortic stenosis) or (ii) blood flow is leaking back into heart (aortic regurgitation).As a result of severe stenosis or regurgitation, the aortic valve must be replaced. Otherwise, future heart complications (enlarged heart muscle, congestive heart failure) can occur due to the strain on the cardiac muscle. Aortic valve replacement surgery may also be needed if the heart valve leaflets have become damaged due to aortic valve calcification, a congenital bicuspid aortic valve, or other forms of aortic valve disease