A less invasive valve surgery
Date: April 1, 2012
The third time would not have been the charm for Michael Junker, 34, a former postal carrier from Pittsburgh. After undergoing two heart valve operations in 12 years, Junker faced a serious challenge with the return of valve stenosis, a condition in which the narrowing of the heart’s aortic valve blocks blood flow from the heart to the rest of the body.
“We knew that a third conventional valve replacement would have been too risky,” says Johns Hopkins cardiac surgeon John Conte. The only choice for Junker was a procedure called apical aortic conduit surgery, an operation in which surgeons use a synthetic tube-shaped graft with a mechanical valve to provide an alternative route for blood to leave the heart.
This type of surgery is considered only for patients in certain special circumstances. Junker, who had the procedure and is doing fine, says he is grateful that the apical conduit was a viable option for him.
Conte, however, believes that now there may be another possibility for patients like Junker: a less invasive way to replace a malfunctioning aortic valve that does not involve opening the chest. He and Johns Hopkins cardiologist Jon Resar are taking part in one of two major U.S. studies on the procedure—transcatheter aortic valve implantation (TAVI)—which has already shown considerable promise in Europe.
The minimally invasive procedure involves the use of a porcine (pig) valve encased in a stent, which is fed through the femoral artery, located in the thigh, to the heart. A balloon is opened inside the existing valve to push away the blockage and make room for the replacement valve. In its expansive new location in The Johns Hopkins Hospital’s new clinical building, the Heart and Vascular Institute provides the perfect clinical setting for performing TAVI. There, “hybrid” procedure rooms outfitted with sophisticated imaging and other technology allow medical and surgical specialists to work side by side to ensure that patients receive the most appropriate procedures in the safest possible environment.
Patients are eligible for the TAVI study if they are not good candidates for conventional surgery because advanced age, previous procedures or if multiple health conditions put them at high risk. They are randomized to receive either the transcatheter approach or surgical valve replacement. A second group of patients for whom surgery is totally ruled out will receive angioplasty.