The pulmonary valve is attached to the right ventricle of the heart. It is the passageway through which blood flows to get to the lungs for oxygenation. Pulmonary stenosis, a congenital heart defect, is a narrowing of the leaflets of this valve, or of the valve itself. The leaflets open as the right ventricle contracts and pushes blood to the lungs, but when they are stenotic, the leaflets can stick or remain partially closed. Pulmonary stenosis is the most common of valve defects.
In many cases, pulmonary stenosis is mild and the narrowing does not significantly inhibit blood flow to the lungs. Peripheral pulmonary stenosis narrows the valve itself, but is generally mild. Such mild cases usually never require treatment, although physicians may hear a heart murmur when a stethoscope is applied to the chest of a newborn. The risk with more serious forms of pulmonary stenosis is back up of fluid into the heart and veins, and the need for the right ventricle to pump harder to move blood into the lungs. Over time, the extra work the heart is doing can result in heart failure.
The most common intervention for treating pulmonary stenosis is non-surgical. During a cardiac catheterization, a small balloon attached to the catheter is threaded through the heart to the pulmonary valve and then inflated to reduce narrowing. This treatment, balloon valvuloplasty, has a high degree of success. It also has the advantage of being an outpatient procedure when successful.
Sometimes balloon valvuloplasty is not enough. The procedure may be attempted to address the pulmonary stenosis, but may not be successful. If pulmonary stenosis still exists, several surgical options are available. The most common option is to excise the valve and replace it with either a pig valve, or a human valve from a cadaver. Unlike other transplants, rejection is not a factor in this surgery.
Children with this type of surgery generally do extremely well, but the valve does not grow with them, so at some point replacement of the valve is necessary. With most children, this may be done about ten years after the initial valve placement. Valve replacement, though it sounds serious, is considered a fairly routine procedure by most cardiothoracic surgeons.
Survival rates are excellent for valve replacements. Because of the artificial valve, cardiologists recommend antibiotics before dental procedures. Additionally, a child may be placed on long-term aspirin to prevent clots from forming in the new valve. The child will need to see a cardiologist yearly. This physician will assess the degree to which the new valve is working, and also determine when the valve might need replacement.
A child with pulmonary stenosis rarely needs immediate intervention right after birth. Pulmonary stenosis affects the heart over time, and the effect is varied by the degree of stenosis. Frequently, though, pulmonary stenosis is present with other defects, as in Tetralogy of Fallot, or hypoplastic right heart syndrome. In these cases, surgery may need to be performed shortly after birth to address these other defects.