Catheter-Based Valve Implantation

Overview

A normal human heart has four valves that direct blood flow through the heart, ensuring blood travels in one direction. Many forms of congenital heart disease (CHD) involve the pulmonary valve, which connects the heart to the blood vessels on the lungs. Many patients with this form of CHD require some form of open-heart surgery where an artificial pulmonary valve is implanted between the right ventricle and pulmonary artery.

However, these valves can become dysfunctional over time. A variety of problems can occur:

• The patient may outgrow the artificial valve.
• The valve can become stiff or narrowed over time and, therefore, doesn't open properly.
• The valve can become leaky over time and, therefore, doesn't close properly.

Other forms of CHD affecting the pulmonary valve are treated with surgery or catheter-based techniques to repair a narrowed pulmonary valve, though this often results in leakiness of the valve over time. In many cases, this requires replacing the original pulmonary valve with an artificial pulmonary valve.

Pulmonary valves can be replaced with open-heart surgery, but with recent advances in technology, many patients can now get a new pulmonary valve using catheter-based techniques, thus avoiding open-heart surgery. A thin, flexible tube called a catheter is inserted into a blood vessel to deliver treatments. This form of treatment requires only a puncture site in the skin, in contrast to more invasive open-heart surgery.

Not all patients who have problems with the pulmonary valve are candidates for catheter-based pulmonary valve implantation. Speak with your cardiologist to see if you're a good candidate.

1. During a catheter-based valve implantation, a large catheter is placed in a central vein, usually in the leg, and advanced to the heart and the pulmonary valve.
2. Separate wire cages, or stents, are sometimes placed in the existing pulmonary valve area to strengthen it and prepare it for the new valve implantation.
3. The valve is placed the same way other stents are placed: The stent is threaded to the procedure site via a catheter. A balloon tip on the catheter is opened to expand the stent into place.
4. The balloon is then deflated and the catheter is removed, leaving only the valve in the body. The new valve opens completely to let blood flow out freely and closes to prevent blood from leaking back into the heart.
5. After the procedure, most patients are usually in the hospital only overnight. Children and adults undergoing this procedure can usually return to normal activity within a few days.

Currently, the pulmonary valve is the most common valve that’s placed by catheter techniques in both children and adults with CHD. In some cases, the tricuspid and mitral valves can also be replaced with catheter techniques, and in certain adults, an aortic valve may be replaced with a catheter.