Several different kinds of artificial valves are used for replacement surgery, including:
- Mechanical valves
- Tissue valves, which are discussed below
- Homograft valves, which are also discussed below
- Ross procedure
Several tissue valves are currently used at Cedars-Sinai. The Carpentier-Edwards pericardial valve and the St. Jude Toronto Stentless Porcine valve are the most common.
These valves offer less resistance to the blood flowing through it and patient do not need to take blood thinners. The disadvantage is that these valves usually only last about 15 years.
Tissue valves are recommended for patients who:
- Cannot or will not take blood thinners
- Are younger than 65 years old and need aortic valve replacement but do not have risk factors for blocked valves or who are younger than 70 years old and need mitral valve replacement
- Need to have a blocked mechanical valve replaced
- Are in kidney failure, on hemodialysis or have hypercalcemia (high blood calcium)
- Who are in adolescence and still growing
Homograft valves are donated human aortic valves that are used in select cases. These valves may result in less risk of infection, but the operation is more complex than standard valve replacement.
Homografts are the most resistant to infection, making this the preferred technique for treating aortic root infection and endocarditis at Cedars-Sinai.
The major disadvantages of a homograft include issues with the longevity, the size and the length. Since homografts depend on human donor availability, there is no assurance that there will be enough valves of the right size and length when needed.
Because our bodies try to reject foreign objects - even when they are present to help, such as replacement valves - severe calcification of the aortic wall may occur, stiffening the leaflets, making the valve less effective. The leaflets of the aortic valve also may degenerate.
Homografts may be considered for elderly patient with a life expectancy less than 15 years who are being treated for a heavily calcified (porcelain or egg shell) aorta. In such cases, a homograft would be done in lieu of other types of aortic valve replacement and endarterectomy of the aorta.