Reconstructing the Tricuspid Valve Using the Patient’s Own Tissue
In a healthy heart, the tricuspid valve acts as a one-way gate between the two right chambers, allowing blood to flow from the upper chamber (the right atrium) to the lower chamber (the right ventricle). Then the gate closes tightly so blood can’t flow backward.
In children born with Ebstein’s anomaly, the tricuspid valve is malformed and in the wrong place. As a result, blood leaks backward from the right ventricle to the right atrium. The right ventricle shrinks and the right atrium becomes abnormally large. Other heart defects often occur along with Ebstein’s anomaly. The condition is named for the German doctor who first identified it in 1866.
Many techniques used to correct Ebstein’s anomaly ultimately failed and the tricuspid valve had to be replaced with a mechanical valve or one made of animal tissue (a bioprosthetic valve). Such artificial valves, however, have limitations. The tissue valve has limited duration due to either calcification or tissue degeneration (failure). Also — important when the patient is a child — an artificial valve doesn’t grow with the child and eventually must be replaced. Therefore, after valve replacement, the patients will need reoperations over time.
As a trainee cardiovascular surgeon at the Cleveland Clinic Foundation, José Pedro da Silva, MD, observed these challenges. Back home in his native Brazil, he devised a new technique, using tissue from the patient’s own malfunctioning tricuspid valve to create a new, cone-shaped valve.
Unlike previous techniques to repair Ebstein’s anomaly, cone reconstruction — also known as the cone procedure — closely mimics the normal anatomy of the tricuspid valve. The reconstructed valve is made of the patient’s own tissue, so the body doesn’t reject it. In children, the reconstructed valve grows with the patient, so it doesn’t need to be replaced in a few years.
To date Dr. da Silva has performed more than 200 cone procedures. In the last 10 years, since the technique has been perfected and the best age determined, the results have improved substantially with very low mortality and nearly no need for valve replacement. The cone procedure has been performed around the world on patients ranging from newborns a few days old to adults aged 49 and is considered the “gold standard” for repairing Ebstein’s anomaly.