There are two types of replacement valves that can replace an unhealthy valve in the heart.
One type is a man-made mechanical valve, made of metal and plastic. The other type of valve is taken from an infection-free animal heart.
Mechanical and tissue valves each have specific advantages and disadvantages. If a mechanical valve is chosen to replace the original valve, you will need to take coumadin after the procedure for the rest of your life. Coumadin helps prevent blood clots from forming on the new valve. With coumadin, you will need to have blood tests on a regular basis. The advantage of a mechanical valve is that it may possibly last the rest of your life.
Tissue valves have the advantage of not usually needing a long-term medication like coumadin. The disadvantage of tissue valves is they don't often last as long as a mechanical valve. They will last an average of 10-15 years before they need to be replaced with another valve.Tissue valves also have a risk of stroke after they are implanted. Certainly their risk is much less then a mechanical valve but a few patients per one thousand can have a stroke with a tissue valve. For this reason, some surgeons will place patients with tissue valves on coumadin for 3 months after surgery. However the risk of stroke with a tissue valve in the long term is far less than a mechanical valve.