A single degree of oversize does not fit all valve types.

Moderate valve oversize increases the risk of aortic regurgitation with self-expandable valves, and larger oversizing may be preferable with this valve type. Large oversizing increases the risk of aortic annular rupture in patients treated with balloon-expandable valves and less oversizing appears safer. Anatomical factors may also may influence procedural success and should not be overlooked.