Development of a new clamplike device that positions and holds the heart for correct placement of lines of ablation has simplified and shortened the Cox-maze procedure for treatment of atrial fibrillation, according to an article in the February issue of the Journal of Thoracic and Cardiovascular Surgery.

Heart surgeons at Washington University School of Medicine in St. Louis, the same institution at which the original procedure was developed, developed and tested the device that radically shortens and simplifies a complex surgical procedure that has had the best long-term cure rate for persistent atrial fibrillation. The simplified procedure is termed Cox-maze IV, and the surgeons believe it can replace the older "cut and sew" Cox-maze III in which ten precisely placed incisions in the heart muscle created a maze to redirect aberrant electrical impulses.

"This technology has made the Cox-maze procedure much easier and quicker to perform," said Ralph Damiano Jr., MD, the John Shoenberg Professor of Surgery and chief of cardiac surgery at the School of Medicine and a cardiac surgeon at Barnes-Jewish Hospital. "Instead of reserving the Cox-maze procedure for a select group of patients, we would urge use of this device for virtually all patients who have atrial fibrillation and are scheduled for other cardiac surgery."

The device heats heart tissue using radiofrequency energy. By holding areas of the heart within the jaws of the device, surgeons can create lines of ablation. In the older Cox-maze III procedure, the lines of ablation were made by cutting myocardium, sewing incisions back together and letting a scar form.

In the current study, University surgeons showed that Cox-maze IV is just as effective as Cox-maze III for curing atrial fibrillation, yet takes one third the time to perform.

"The older Cox-maze procedure was a very complicated operation, and very few surgeons were willing to do it," said Damiano. "So we started working on new technology and helped develop an effective ablation device that simplifies the procedure. Not only is Cox-maze IV shorter, but with the new device the procedure is also much safer because there's a much lower risk of bleeding."

Damiano said the most recent study of Cox-maze IV was unique because the surgeons carefully matched age, sex and cardiac conditions of a group of patients who underwent Cox-maze III in the past with patients undergoing Cox-maze IV.

"This is the first documentation of the effectiveness of the ablation device compared to the incisions of the Cox-maze III," said Damiano. "This operation is very effective, and we now use the Cox-maze IV technique exclusively."