What is heart valve replacement surgery?
Heart valve replacement refers to procedures aimed at replacing your own heart valve, rather than repairing your own valve. If a surgeon cannot repair a heart valve, the valve is removed and replaced with an artificial (prosthetic) valve by sewing it into the remaining tissue from the natural valve. Throughout the world, 95% of all valve replacements are performed for mitral or
aortic valves. The mitral valve is positioned in the heart´s left side, between the left upper chamber (left atrium) and the left lower chamber (left ventricle). The aortic valve separates the left ventricle from the aorta (which carries blood to the body).
In a heart valve replacement, a malfunctioning natural heart valve is replaced surgically with a prosthetic valve. A prosthetic valve can replace any of the three heart valves — aortic, pulmonary or tricuspid. A prosthetic valve is a synthetic or tissue substitute for the natural valve. It is designed to mimic the natural valve's normal opening and closing motions. Prosthetic heart valves are divided into two basic categories: synthetic mechanical valves and biological valves made of human or animal tissue.
There are 2 kinds of valves used for valve replacement:
Mechanical valves, which are usually made from materials such as plastic, carbon, or metal. Mechanical valves are strong, and they last a long time. Because blood tends to stick to mechanical valves and create blood clots, patients with these valves will need to take blood-thinning medicines (called anticoagulants) for the rest of their lives.
Biological valves, which are made from animal tissue (called a xenograft) or taken from the human tissue of a donated heart (called an allograft or homograft). Sometimes, a patient's own tissue can be used for valve replacement (called an autograft). Patients with biological valves usually do not need to take blood-thinning medicines. These valves are not as strong as mechanical valves, though, and they may need to be replaced every 10 years or so. Biological valves break down even faster in children and young adults, so these valves are used most often in elderly patients.
A homograft or allograft is a human valve obtained from a donor. This type of valve is particularly beneficial for pregnant women and children, because it does not require long-term anticoagulation therapy. In addition, it can provide excellent hemodynamic performance, allowing for natural function of the surrounding structures. Because the availability of these valves depends on donors, supply is limited.