The maze operation - Surgical therapy for chronic atrial fibrillation: Modification to the mini-maze procedure

Summary Objective: Atrial fibrillation (AF) is the most common arrhythmia. However, its precise electrophysiologic mechanism is still not well understood. Chronic symptomatic atrial fibrillation resistant to medical therapy can successfully be treated by the Maze III procedure (M III). Several publications are dealing with alternative surgical techniques. This study describes technique and midterm results of a Mini-variant (Mini) of the Maze III procedure. Methods: During a 48-month period we performed either a M III (group I = 7 patients) or a Mini-Maze operation (group II = 65 patients) in 33 males and 39 females with chronic symptomatic atrial fibrillation and additional cardiac pathology. Patients were controlled 4.0 ± 1.8 months (group I) respectively 3.6 ± 0.8 months (group II) (NS) and 16.75 ± 2.5 months (group I) respectively 13.2 ± 1.9 months (group II) (NS) after operation by means of thorough electrophysiological assessment, right heart catheterization, MRI, echocardiography, stress-ECG and 24h-ECG. Results: There was no significant difference between the two groups with regard to sex, age and duration of AF. Echocardiographic left atrial diameter (LAD) was 75 ± 11 mm in group I and 65 ± 8 mm in group II (p = 0.002). Whereas right atrial diameter was 62 ± 8 mm in group I and 57 ± 7 mm in group II (NS). Perioperative data (n = 72): Aortic cross clamp time was 127 ± 40 min in group I and 87 ± 22 min in group II (p = 0.0002). Cardiopulmonary bypass time was 185 ± 71 min in group I and 137 ± 42 min in group II (p = 0.01). Postoperative data I (first follow-up: n = 66): sinus rhythm (yes): 4/7 vs. 47/59 (NS); pacemaker (PM) in AAI mode (yes): 1/7 vs. 3/59 (NS); inducible atrial fibrillation (yes): 2/7 vs. 5/59 (NS); Bradycardie Tachycardie Syndrome with the need of PM implantation 0/7 vs. 4/59 (NS). Postoperative data H (second followup: n = 55): sinus rhythm (yes): 5/7 vs. 34/48 (NS); PM in AAI mode (yes): 0/7 vs. 4/48 (NS); Inducible atrial fibrillation (yes): 2/7 vs. 5/48 (NS); Bradycardia Tachycardia Syndrome with the need of PM Implantation 0/7 vs. 5/48. Conclusion: Midterm results are identical after M III and Mini. The Mini-Maze procedure is less complex compared to the Maze III procedure and there is a significant reduction of crossclamp and ECC times. We recommend the Mini especially for polymorbid patients and for those with poor left ventricular function.