Surgical ablation procedure
The lesion sets for AF ablation consisted of left and right atrial ablation lesions. The left atrial lesion set was started with a conventional left atrial incision through the interatrial groove and extended to the inferior-posterior wall of the left atrium (LA). If the LA anteroposterior diameter was >50 mm, resection of the posterior wall of the LA was performed via LA reduction plasty. A box lesion was then made using an argon-based flexible cryoablation system, Cardioblate CryoFlex (Medtronic, Minneapolis, MN). A mitral isthmus endocardial lesion was made between the pulmonary box lesion and the mitral annulus. Additional coronary sinuses were ablated using the epicardial approach. Right-sided endocardial ablation was initiated through an oblique right atrial incision. Cavotricuspid isthmus ablation, right atrial anterior free wall ablation, and intercaval ablation were achieved using the cryoablation probe.
Concomitant bi-atrial ablation was performed in 184 patients (71 %), and others received left –sided ablation. The most common concomitant surgery was mitral valve surgery ± tricuspid annuloplasty (64.5%), followed by aortic valve surgery ± tricuspid annuloplasty (9.3%), mitral valve surgery + aortic valve surgery ± tricuspid annuloplasty (12.7%), and coronary artery bypass grafting surgery (1.2%); only 13 cases (5.0%) of isolated surgical ablation were conducted.