Totally Endoscopic Surgical Ablation in Patients with Lone AF: Bilateral Complex versus Unilateral Approach

Objective: Comparison of two different types of totally endoscopic surgical epimyocardial ablation.

Methods: Since December 2010, 23 pts were referred for surgical ablation due to long-standing persistent atrial fibrillation (AF) combined with significant atrial dilation. Ablation was done in 11 patients via bilateral endoscopic approach using bipolar RF energy application (Group I) and in 12 patients via unilateral endoscopic approach using the Cobra Fusion System (Group II). Both groups presented with similar preoperative characteristics: mean age (60 ± 8 vs. 59 ± 9 years; p = 0.86), body mass index (32 vs. 30; p = 0.45), duration of AF (5.2 ± 2.6 vs. 7.5 ± 8 years; p = 0.38) and mean left atrial diameter (156 ± 82 vs. 108 ± 34 mL; p = 0.076) Rhythm monitoring was achieved by an implantable loop recorder or repeated 24h Holter ECG.

Results: All patients in group I successfully received bilateral pulmonary vein isolation + box lesion + trigonal lesion and left atrial appendage resection. Patients in group II were treated with a box lesion only. Mean duration of procedure was 235 ± 70 versus 175 ± 46 minutes (Gr. I vs. II; p = 0.02). There were no intraoperative complications besides one patient with persistent unilateral phrenic nerve palsy in each group. Mean follow-up time was 23 ± 9 vs. 23 ± 12 months (p = 0.88). Freedom from AF in group I compared with group II was: 73 vs. 67% at discharge (p = 1.0), 81 versus 58% (p = 0.37) at 3 and 81 versus 67% (p = 0.64) at 6 and 12 months follow-up. Success rate at latest follow-up, without additional catheter based ablation was 81 vs. 58% (p = 0.37) in group I and II, respectively. Including interventional therapies, freedom from AF at latest follow-up, was higher in group I compared with group II 91% versus 75% (p = 0.317) but without statistical significance. These included in Group I, 2 (18%) procedures with left- (n = 1) and biatrial (n = 1) defragmentation. 1 of those led to stable SR. In Group II, 4 (33%) procedures included isolation of pulmonary veins (n = 2), coronary sinus ostium and right isthmus (n = 1). Two of those patients attained SR.

Conclusion: Totally endoscopic stand-alone ablation allows very good success rates in this highly challenging population. Especially when using an isolated left-atrial box lesion, a staged approach with additional catheter-based ablation seems to be necessary to achieve higher success rates.