Hi Dwilli,
There are many posts here regarding valve types. Do a "search" on valve selection, or valve types and see what you find.
Also, the choice of valve incoporates many variables. Your age is an important one, as well as your life style and medical reason for the surgery. All of these factors help in making your valve selection choice.
Here is some information from the Harvard Medical School Web site.
Mechanical heart valves that have been approved by the U.S. Food and Drug Administration rarely fail. However, even in patients who are taking adequate doses of anticoagulants, a small number develop blood clots on the valves. Each year, 1.3 percent to 2.7 percent of patients who have a mechanical heart valve experience an episode of severe anticoagulant-related bleeding.
Biological valves tend to fail over time ? requiring replacement in 30 percent of patients by ten years and 50 percent by fifteen years. However, the risk of blood clots is very low.
Biological Valves
Biological valves can be made of either human or animal tissue. Options include:
Autograft valves ? In this case, the replacement valve is made from another valve within the patient's own heart. For example, the patient's pulmonary valve may be removed and used as an autograft to fix the aortic valve. The missing pulmonary valve is then replaced by a donated human homograft or an animal heterograft (see below).
Homograft valves ? This replacement valve is taken from a deceased human donor.
Heterograft valves ? In this case, the replacement valve comes from an animal donor, either a pig (porcine heterograft) or a cow (bovine heterograft).
In general, biological valves are less durable than mechanical valves. They wear out faster and need to be replaced sooner.. Because of this need for earlier replacement, biological valves are more commonly used in people age 65 to 70 or older, where predicted lifespan is often a factor in valve choice. Since the long-term risk for thromboembolism is lower for biological valves than for mechanical valves, the patient doesn't normally need to take anticoagulants for more than three months after surgery.
Currently, 71,000 to 79,000 heart valve replacements are performed each year in the United States.
Hope this is helpful,
Rob