For people about to undergo a heart-valve replacement, the idea of having surgery on their most vital organ can be scary. But rest assured the procedure is very common. Here, we’ll explain why valve replacement may be necessary and take a look at the options.
The heart has four valves responsible for keeping blood moving in a circular pattern through the organ. The aortic and mitral valves are located on the left side, the pulmonary and tricuspid valves on the right. Each valve has “flaps” that work like a gate that closes before the blood can flow backward from where it came.
Over time or due to certain conditions, such as rheumatic fever, bacterial infection or a leak, a valve can weaken and harden, preventing blood from circulating properly. Most commonly affected is the aortic valve because of the high demands placed on it.
If the valve is only slightly damaged, the doctor may be able to repair it by removing the worn tissue and inserting a “ring” to keep the valve in shape. However, when the valve is beyond repair, it must be replaced.
Human, or homograft, valves are derived from organ donors. These valves are more easily accepted by the body than other types because they are natural. In addition, unlike other types of replacement valves, human valves do not increase the risk of blood clots, so patients receiving human valves do not need blood-thinning medication. However, there is a small risk of viral infection from the transfer. Human valves typically last 15 to 20 years.
Pulmonary autograft valves require the surgeon to remove the patient’s pulmonary valve and use it as a replacement for his or her aortic valve. The pulmonary valve is then replaced with a donor homograft valve. Since the pulmonary valve is under less strain than the aortic valve, less risk is involved in replacing it with a donor valve. This option is often used for children or young adults born with heart defects because it lasts about 20 years. After it has been repositioned, the pulmonary valve continues to grow.
Bioprosthetic valves are animal valves that have been sterilized and treated for human use. In most cases, blood thinners are not necessary. Complications, such as bleeding problems and stroke, are rare. Bioprosthetic valves last about 10 years.
Pericardial bioprosthesis valves are made from animal tissue and man-made materials. The “flaps” are made from cow tissue and the rest of the valve is constructed from materials like plastic and polyester. Most last at least 14 years.
Mechanical valves, made of plastic, cloth and metal, can last a lifetime. Even though the parts are specially coated to prevent blood clots, the risk is still present. These artificial valves also may increase the risk of a stroke or infection. Since patients who receive mechanical valves must take blood thinners for life, this option may be appropriate for patients already on such medication.