"Because of the devices, the procedure - called the Cox-Maze procedure - has gone from an operation that hardly anyone was doing to one that 80 to 90 percent of U.S. heart surgeons are now performing," says Ralph J. Damiano Jr., M.D., the John Shoenberg Professor of Surgery and chief of cardiac surgery at the School of Medicine and a cardiac surgeon at Barnes-Jewish Hospital.
Damiano and his colleagues found that surgeons needed to apply the devices for only a few seconds at a time to get effective ablation of the atrial wall, and the devices caused no injury to surrounding tissue. The time needed for the procedure went from more than 90 minutes to about 30 minutes. The procedure calls for ten precisely placed incisions in the upper chambers of the heart. The incisions are then sewn up and eventually form scars in the atrial tissue.
The scar tissue stops atrial fibrillation by interfering with chaotic electrical signals that cause the atria to contract irregularly. By placing roadblocks in the way of these misplaced electrical impulses, the Cox-Maze procedure redirects them down their normal route so that they stimulate regular heartbeats. The clamp-like jaws of the radiofrequency ablation devices latch onto a section of heart muscle and deliver a thin, focused line of energy that heats and ablates the tissue. Ablation with the devices can replace all but two small incisions that would typically be made during a traditional Cox-Maze procedure.
"We've not only reduced the time needed for the procedure, we've made the procedure easier to perform," Damiano says. "In addition to eliminating most of the incisions, the radiofrequency ablation clamp removes the potential for error by monitoring when the lesion goes all the way through the tissue and automatically shutting the power off at that point."
MEDICA.de; Source: Washington University