Valve replacement surgery is performed when valve repair surgery is not a treatment option. valve replacement surgery is most often used to treat patients with aortic valve disease, particularly aortic stenosis.
Valve replacement surgery involves removing the faulty valve (native valve) and replacing it with a biological or mechanical valve that is sewn to the annulus of the native valve. All valve replacements are "biocompatible,"which means your new valve will not be rejected by your immune system.
Biological Valves
Biological valves (also called tissue or bioprosthetic valves) are made of cow tissue (bovine), pig tissue (porcine) or human tissue (allografts or homografts). Biological valves may have some artificial parts to give the valve support and to make placement easier.
A homograft (also called allograft) is a human heart valve that comes from a donor after death. It is frozen and preserved under sterile conditions. A homograft is most often used to replace a diseased aortic valve in children or young adults, especially when the aortic root is diseased or there is infection (endocarditis).
There are advantages and drawbacks to biologic valves.
Advantages: Most patients do not need to be on lifelong blood-thinner medication, unless they have other conditions (such as atrial fibrillation) which warrant it.
Drawbacks: Traditionally, biological valves were not considered as durable as mechanical valves, especially in younger people. Previously available biologic valves usually needed to be re-replaced after about 10 years However, recent studies show these valves often last 15 - 20+ years without a decline in function.
Mechanical valves are made of metal or carbon and are designed to work just like a patient's native valve. Mechanical valves, are well-tolerated by the body, very durable and designed to last a lifetime.
The bileaflet valve is the most common type of mechanical valve. It is made up of two carbon leaflets mounted in a ring covered with polyester knit fabric.
There are advantages and drawbacks to mechanical valves.
Advantages: Mechanical valves are very durable. They are designed to last a lifetime.
Disadvantages: Due to the artificial material involved, patients who receive these valves need to take a blood-thinning (anticoagulant) medication lifelong. Blood-thinners are medications (such as warfarin or Coumadin) delay the clotting action of the blood. They help prevent clots from forming on the replaced valve, which can cause a heart attack or stroke. If you take Coumadin, you will need to have regular blood tests to see how well you are responding to the medication and if you need a change in dose.
Some patients who have a mechanical valve replacement hear the valve make a clicking noise at times. This is the sound of the valve leaflets opening and closing.
The decision whether to choose a bioprosthetic or a mechanical valve is based on a number of choices - including patient choice. In younger patients, the patient may weigh issues such as the inconvenience and risk of bleeding related to taking a blood thinner (coumadin) with the risk of work or lifestyle related injury, or the possibility of reoperation during their lifetime. In patients more than 60 years of age, the bovine pericardial valve will probably last for the duration of the patient's life.
