How do heart valve replacements work?

Remove/Replace: The heart is stopped. The patient is placed on bypass which pumps blood and breathes for the patient while the heart and lungs are not being used. The old valve is removed and a new valve is stitched in place. This can be either a "tissue valve" from a pig or cow, or a mechanical valve which is completely artificial.

Valve replacement: The surgery replaces the valve with either a mechanical or animal tissue valve. This is done on a heart lung machine. The valve takes the place of the damaged valve and the patient lives their life with a new disease 'artificial valve' with its own set of problems. The obstruction or valve leak of the diseased valve is corrected by the artificial valve. Sometimes blood thinners are needed.