Heart valve replacement is an open-heart surgery in which a defective valve that cannot be repaired is replaced with one of two basic types of valves. This type of procedure is typically used on heart valves that leak or on those that have thickened, hardened or stretched. The two basic types of artificial valves used are:
- Biological valve. This type of valve may be an autograft (from the patient’s own body), a xenograft (from a pig or cow) or an allograft or homograft (from a cadaver). For example, one autograft technique is known as the Ross procedure, in which the damaged aortic valve is replaced with the patient’s own pulmonic valve. The patient’s pulmonic valve is then replaced with a valve from a cadaver. Heart-valve tissue can also be donated by a living, matching donor. Biological valves last about 10 or 15 years before they start to fail due to tissue disintegration. If a biological valve starts to fail, it can usually be replaced with another.
- Mechanical valve. This type of valve is made from metal or other man-made (synthetic) materials. Mechanical valves are designed to last about 30 years, so they are often used if all other factors are equal. However, they carry a higher risk of blood
clots , so patients with mechanical valves must take anticoagulants to help prevent the formation of blood clots.
The open-heart surgery necessary for a valve repair or replacement is described in more detail in the following sections.
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