Left atrial versus bi-atrial maze operation using intraoperatively cooled-tip radiofrequency ablation in patients undergoing open-heart surgery

OBJECTIVES We sought to determine whether limited left atrial Maze surgery encircling each of the pulmonary veins, using cooled-tip radiofrequency (RF) ablation, is as effective as the bi-atrial approach? BACKGROUND The original Cox/Maze operation effectively restores sinus rhythm (SR) in patients with atrial fibrillation (AF). Ablation procedures aimed at eliminating pulmonary vein foci have produced promising short-term success. METHODS This was a prospective analysis of patients with chronic AF undergoing open-heart surgery in addition to the Maze operation, using intraoperatively cooled-tip RF ablation either in the left atrium alone (group A) or in both atria (group B). RESULTS Patients in group A (n = 21) and group B (n = 49) did not differ in terms of their baseline characteristics. Concomitant open-heart surgical procedures included mitral valve replacement (3 vs. 25), mitral valve plasty (0 vs. 2), mitral and aortic valve replacement (1 vs. 1), aortic valve replacement (4 vs. 6) and coronary artery bypass grafting (13 vs. 15) in groups A and B, respectively. Follow-up ranged from 1 to 50 months. The overall cumulative rates of SR were 82% in group A and 75% in group B, without a statistically significant difference (p = 0.571). Bi-atrial contraction was revealed in 92.3% of patients in SR in group A and in 79.2% in group B. The cumulative survival rates were 90.5% in group A and 77.9% in group B (p = 0.880). CONCLUSIONS A left or bi-atrial Maze operation using intraoperatively cooled-tip RF ablation can safely be combined with open-heart surgery. A left atrial Maze procedure seems to be as effective as the bi-atrial procedure and restores SR in 82% of patients.