Predictors of success of the modified maze procedure using radiofrequency device.

The modified maze procedure using radiofrequency devices has become an increasingly common surgical option for patients with atrial fibrillation. Several lesion sets have been proposed and tested, but it remains unclear which yields the best results. We studied 61 patients who underwent the modified maze procedure using radiofrequency devices from March 2005. The pulmonary veins were isolated separately on both sides, and a connecting lesion was made inferiorly in the early series of 30 patients (group 1). In 31 patients (group 2) treated from May 2007, we added a superior connecting lesion between both pulmonary veins (completing a box lesion), and also performed coronary sinus ablation from the epicardial side, using a monopolar device. At 6 months postoperatively, maintenance of sinus rhythm with and without antiarrhythmic medications was 70% and 63%, respectively in group 1, and 94% and 90% in group 2 (both p<0.05). Multivariate analysis indicated that the box lesion with coronary sinus ablation was an independent predictor of the maintenance of sinus rhythm at 6 months. These 2 lesions should not be eliminated from the modified maze procedure.