The conventional way of mitral or left atrioventricular valve surgery was to replace the valve.

However, it is now generally agreed that where possible the valve should be repaired and not replaced.

In mitral valve replacement, an artificial mitral valve replaces the native valve.

Two kinds of prosthetic heart valves are available.

Mechanical valves are created from manmade materials.

Though these valves last long, patients are required to take anticoagulant medication to prevent blood clots on or around the valve.

Biological (tissue) valves are taken from cows or human donors.

Biological valves do not last if mechanical valves.

However, when biological valves are used, long-term therapy with anticoagulant medication often is not necessary.