Valve Replacement Surgery

When a valve is badly deformed, valve repair is not an option. In these cases, the patient's damaged valve is removed and replaced with a prosthetic valve. Although mechanical and tissue valves each have advantages, the search for the perfect prosthetic valve for replacement continues.

Prosthetic Valves

Bioprosthesis

This tissue valve is taken from animal (figures 1A & 1B), chemically treated and prepared for human use. Once the tissue valve is prepared, it may be sewn into a frame to support the valves and leaflets. Some of the tissue is prepared without a frame and is commonly referred to as a stentless valve (figure 2). Surgeons may choose a stentless valve when a larger valve size is needed. Larger valves generally provide more surface area for blood flow to meet the body’s needs. Tissue valves have the advantage of not requiring blood anticoagulation medication but are not as durable as mechanical valves. Depending on the age of the person, a bioprosthesis may need to be re-replaced in 10 to 18 years.

Mechanical Valve

A mechanical valve (figure 3) is designed out of metal and other materials to mimic the native valve. To prevent blood clots from forming on the valve, anticoagulation medicine (blood thinners) are required. This medication is taken daily and requires close supervision and regular blood tests. Chronic blood thinning medication may not be a desirable option for individuals who engage in vigorous physical activity or contact sports or for women who wish to have children.

Homograft

A homograft (figure 4) is a human valve obtained from a donor. It is also treated and prepared for use. Like bioprostheses, homografts do not require long-term anticoagulation medicines. Because they are a human valve, they also can promote a more natural function of the surrounding structures in the heart. They are comparable in durability to a bioprosthesis but the 20-year durability results (which would compare with the durability of the mechanical valve) are not yet available. While homografts are in short supply, they are another alternative for some patient populations.

At Hoag Heart Valve Center, all three valve types are available. Each prosthetic valve has advantages and disadvantages. Prior to valve replacement surgery, the patient, cardiologist and cardiac surgeon discuss the options and make the decision based on lifestyle, age, medical history and other factors. Heart surgery is considered a major surgical operation. It is associated with the following risks: stroke, intraoperative heart attack, bleeding, infection, arrhythmias and death. Fortunately, these risks are usually low in an otherwise healthy patient. At Hoag, we are proud that the risks from surgery occur only 1% - 2% of the time, compared to the national average of 4-5%.

The Ross Procedure for Aortic Valve Disease

The Ross Procedure (figure 5) is a procedure designed for younger patients (usually 11 to 55 years of age) with a damaged or diseased aortic valve. During this procedure, the patient's own normal pulmonary valve is used to replace the damaged aortic valve, and a pulmonary homograft is used to replace the pulmonary valve. The pulmonary valve is identical in form, size and function to the aortic valve making it an excellent substitute for a diseased or damaged aortic valve. Since the valve is the patient's own living tissue, there is no risk of rejection. The threat of blood clot formation is less than with prosthetic valves and there is no need for blood thinning medication. These advantages and the excellent blood flow characteristics make this an attractive option for children, women of child-bearing age and athletes. The Ross Procedure has been successfully performed at Hoag Hospital since 1996.