Aortic Valve Replacement

ExitCare ImageAortic valve replacement is heart surgery done by a heart surgeon. This type of surgery is used to treat problems with the aortic valve. The aortic valve assists in directing the flow of blood out of the left side of the heart. The left bottom chamber of your heart (left ventricle) is the large muscular chamber of the heart that pumps blood to the rest of the body. The aortic valve separates the left ventricle from the aorta. When the heart squeezes (contracts), the aortic valve opens and allows the blood to flow out of the left ventricle and into the aorta.

Surgery may be necessary when the valve does not open or close completely. A narrowed (stenotic) valve does not let the blood leave the heart normally. This causes blood to back up in the left ventricle and makes it hard for the heart to pump the needed amount of blood through the body. The heart has to work harder. This may produce shortness of breath and fatigue. Problems are worse with activity.

If the valve leaflets do not meet correctly when closing, blood may leak backward into the ventricle each time the heart pumps. This is called aortic insufficiency. When some of the blood leaks backward, the heart has to work harder. The heart can compensate for this increased work for a long time if the leakage comes on gradually. Eventually, the heart fails.

Aortic valve problems may be caused by a birth defect. This is called a congenital condition. Wear and tear can also cause the valve to fail. This is called degenerative disease. Rheumatic fever or infection may damage the aortic valve and later cause the need for valve replacement.

DESCRIPTION OF SURGERY

Aortic valves can be repaired. When the valve is too damaged to repair, the valve must be replaced. An artificial (prosthetic) valve is used to do this. Valves damaged by rheumatic disease often must be replaced.

Three types of prosthetic valves are available:

  • Mechanical valves made entirely from man-made materials.

  • Donor valves made from human donors. These are only used in special situations.

  • Biological valves made from animal tissues.

Each type has advantages and disadvantages. The choice of which type to use should be made by you and your surgeon taking the following into consideration:

  • Your age.

  • Your lifestyle.

  • Other medical conditions.

  • Your preferences with regard to medications and the risk of another surgery.

There are a number of good mechanical valves available. All work well. The main advantage of mechanical valves is that they do not wear out. Their main disadvantage is that blood has a tendency to clot with mechanical valves. If this happens, the valve will not work normally. Because of this, people with mechanical valves must take blood thinners (anticoagulants) for life. There is also a small, but definite, risk of blood clots causing stroke, even when taking anticoagulants.

There are a number of biological valves for aortic valve replacement. Most are made from pig heart valves. The main advantage of a biological valve is that there is a reduced risk of blood clots forming on the valve. This lessens the chance of the valve not working or the valve causing a stroke. A key disadvantage of biological valves is that they wear out sooner than mechanical valves. The rate at which they wear out depends on the person's age. A young boy might wear out a biological valve in only a few years. The same valve might last 10 years in a middle-aged person, and even longer in a person over the age of 70. A biological valve used in a person over 70 years old may never need replacement.

RISKS AND COMPLICATIONS

Your cardiologist and cardiovascular surgeon can best determine your individual risk. It will depend on your age, your general condition, any medical conditions, and your heart function. In general, the risks include:

  • Blood clotting caused by the new valve. Replacement with a mechanical valve requires lifelong treatment with medication to prevent blood clots.

  • Infection in the new valve. Infection is more common with valve replacement than with valve repair.

  • Valve failure. Valve failure is more common with valve replacement than with valve repair. Pig heart valves tend to fail after about 8 to 10 years.

  • Effects from the surgery itself, such as bleeding, infection, and risks of anesthesia. These risks are rare.

PROCEDURE

There are two types of aortic valve replacement surgery:

  • Traditional aortic valve replacement surgery. Valve repair or replacement is open heart surgery. You are given medications to make you sleep (general anesthesic). You are then placed on a heart-lung bypass machine. This machine provides oxygen to your blood while the heart is undergoing surgery. The surgery generally lasts from 3 to 5 hours. During surgery, the surgeon makes a large cut (incision) in the chest. Sometimes the heart is cooled to slow or stop the heartbeat. The damaged aortic valve is removed and replaced with a prosthetic heart valve.

  • Minimally invasive aortic valve replacement surgery. This is done through a smaller incision. The chest is not opened as in traditional surgery. If your condition allows for this procedure, there is often less blood loss, less pain, a shorter hospital stay, and faster recovery compared to traditional surgery.

AFTER THE PROCEDURE

  • Recovery from heart valve surgery usually involves a few days in an intensive care unit (ICU) of a hospital. Full recovery from heart valve surgery can take several months.

  • An anticoagulant, such as warfarin, is often prescribed for 6 weeks to 3 months after surgery for those with biological valves. It is prescribed for life for those with mechanical valves.