The efficiency of the heart as a pump depends not only on the force of its contractions, but also on the correct functioning of its four valves. The valves are subject to a variety of disorders, most commonly the failure to open or close properly. A serious valve disorder can have a progressively debilitating effect that can ultimately be fatal unless the valve is repaired or replaced. According to the Mayo Clinic, valve replacement is the most radical form of treatment for heart valve disease, and even though it carries some risks, it can often bring a remarkable improvement to the patient’s condition. Replacing a valve requires the use of a heart-lung machine and may take several hours to complete.
Repair or Replace
The aortic valve, lying at the point of departure from the left ventricle of the heart into the aorta, is the heart valve that most often requires surgical repair or replacement, according to the U.S. National Library of Medicine. When the valve narrows because of disease, a balloon catheter can expand the valve opening. To replace the valve, the surgeon exposes the aorta, makes appropriate incisions to redirect the flow of blood to the heart-lung bypass machine, and then begins the process of removing and replacing the valve.
Removing
According to the Cleveland Clinic, to remove the valve, the surgeon separates the breastbone, and then cuts through the pericardium to gain access to the heart. In the mean time, the heart-lung machine has taken over the work of circulating highly oxygenated blood through the body while removing carbon dioxide. To gain access to the aortic valve, the surgeon makes an incision into the aorta, above and around the aortic valve.
Replacing
The valve is carefully exposed then removed, leaving a wide ring of tissue around it to allow secure attachment of the replacement valve. The ring of tissue and the sewing ring of the replacement valve are stitched securely together. Once the new valve is in place, the incision in the aorta is sewn closed, the clamp removed, the heart restarted, the heart-lung machine disconnected and the chest closed.
Types of Replacement Valves
Either a mechanical or a tissue valve can replace a human heart valve. According to the U.S. National Library of Medicine, mechanical valves are durable, but tend to encourage the formation of blood clots, so patients receiving them must remain on blood thinners or anticoagulant drugs, for the rest of their lives. Biological valves are less durable, usually only lasting 10 to 15 years. However, using a tissue heart valve will not require the patient to use anticoagulants. According to the Cleveland Clinic, the St. Jude Medical Regent valve and the St. Jude Medical valve are often used to replace aortic and mitral valves, and their use has spanned three decades with excellent results.
