Heart surgeons agree that whenever possible a heart valve should be repaired rather than replaced. Valve repair may be performed to separate fused valve leaflets, sew torn leaflets or reshape parts of the valve. Heart valve repair leaves patients with their own normally functioning tissue, which is resistant to infection and does not require blood-thinning medication.
In some cases, however, the valve is too damaged to repair and must be replaced with a prosthetic (artificial) valve. Valves damaged by rheumatic disease often must be replaced.
Read more about heart valve surgery at Mayo Clinic.