Aortic Valve Surgery
The aortic valve is one of four heart valves that ensures forward flow of blood through the heart. The aortic valve lies between the main pumping chamber of the heart, the left ventricle, and the aorta. Normally, there should be no obstruction to flow and no valve leakage back into the heart once the valve shuts. However, when obstruction or leakage occurs and becomes severe, the patient may develop symptoms that not only can be troublesome, but can also significantly shorten the patient’s lifespan.
Aortic stenosis means narrowing of the aortic valve. Normally, this valve has three leaflets. In younger patients, aortic stenosis most often occurs on congenitally bicuspid (two leaflet) valves, which have degenerated and thickened over time. In older patients, degenerative changes affect trileaflet valves (three leaflet) leading to obstruction. As a result of the blockage, the heart has to work harder to eject blood out the diseased valve, leading to thickening or hypertrophy of the heart. Eventually, symptoms of chest pain, shortness of breath, or fainting may occur and the patient’s survival may be limited to only 2-3 years. At this point, surgery to replace the valve is indicated. If a heart murmur suggestive of aortic stenosis is heard, most physicians will recommend an echocardiogram to assess how severe the stenosis is. Based upon this study and an assessment of the patient’s symptoms, a decision can be made as to whether aortic valve replacement is indicated or not.
Aortic regurgitation means leakage of the aortic valve. Normally, after the heart has ejected blood, the pressure in the aorta closes the aortic valve. Either because of problems affecting the valve leaflets or changes in the size of the aorta that supports the valve, the valve may allow the blood to leak backwards into the heart. Although most patients do quite well with no symptoms despite significant valve leakage, eventually symptoms of shortness of breath and fatigue may develop. Other patients may develop significant enlargement of the heart with a decrease in its function even before symptoms develop. In either of these situations, aortic valve replacement is indicated to improve the long-term outlook.
Aortic valve replacement (AVR) requires use of a heart-lung machine that provides oxygen and blood flow to the body while the heart is stopped. An incision is made in the aorta (not actually in the heart) and the valve is removed and replaced with a new valve.
A variety of different valve types are available, but generally the patient needs to decide with his or her doctor whether a tissue valve or a mechanical valve is preferable. Tissue valves do quite well in older patients, but tend to wear out in younger patients who may require another operation in 10-15 years. One advantage of a tissue valve is that only aspirin is recommended to minimize the risk of blood clotting on the valve, whereas mechanical heart valve will require a daily dose of a blood thinner, Coumadin, indefinitely. However, it is possible that these patients may never need another operation to replace that valve.
Following an uneventful AVR, the patient remains in the hospital for about four to five days and then may be discharged home or to a rehabilitation hospital for a few days of additional care. Patients return for an x-ray, EKG and an office visit, usually two weeks after being discharged. Most patients feel quite well after one to two weeks, but need to limit some activities for about six weeks. It is important that patients become involved in supervised
cardiac rehabilitation. After 6 weeks, most patients are able to go back to work.
Robert M. Bojar, MD