One hundred percent utilization of a modified CryoMaze III procedure for atrial fibrillation with mitral surgery.

Objectives: Concomitant atrial fibrillation often goes untreated because of surgeon concerns regarding lesion set complexity and pump times. We describe a new cryoablation procedure to address this.

Methods: From June 2013 to March 2021, a modified CryoMaze III procedure was used using 3 left atrial ± 3 right atrial cryo-applications creating the key lesions of the Cox Maze III procedure. Since 2018, 3-minute cryo-lesions were used for the left atrial box lesion for total cryoablation times of 8 minutes for the left atrium ± 6 minutes for the right atrium. By using propensity matching, patients undergoing mitral valve surgery with no atrial fibrillation history were compared with CryoMaze III-treated patients.

Results: A total of 100% of the 277 patients with atrial fibrillation requiring mitral valve surgery ± other procedures received the modified CryoMaze III procedure. After propensity score matching (n = 161 each group), the modified CryoMaze III group had mean crossclamp and bypass times 10.5 and 13.4 minutes longer than the control group, respectively. There were no significant differences in 30-day mortality, morbidity, pacemaker use, renal dysfunction, or late survival between groups, but there were less postoperative strokes in the CryoMaze III group. Freedom from atrial fibrillation off antiarrhythmics was 77% (mean follow-up of 3.0 ± 2.1 years). At 12 months, freedom from atrial fibrillation off antiarrhythmics was 90% for the 3-minute ablation group. Late survival was similar to age- and sex-matched Centers for Disease Control and Prevention controls.

Conclusions: The modified CryoMaze III technique is efficient, safe, and effective. Education of the surgical community regarding the late benefits of ablation and the simplicity of this new technique should improve adoption of the Class I Guidelines to treat concomitant atrial fibrillation.