A Modified Maze Versus Cut-and-Sew Maze for Long-Standing Persistent Atrial Fibrillation Concomitant with Mitral Valve Surgery: A Propensity Score-Matched Cohort Study

The cut-and-sew maze (CSM) procedure has an excellent efficacy for the elimination of long-standing persistent atrial fibrillation (AF) concomitant with mitral valve surgery. Because of the complexity and prolongation of cardiopulmonary bypass, CSM has not been widely used. The aim of this study was to examine a modified maze procedure that preserves the "cut-and-sew" procedure in the left atrium and uses cryoablation in the right atrium along with cavotricuspid isthmus.From December 2013 to December 2018, 229 patients underwent CSM, and 43 underwent the modified maze procedure during mitral valve surgery. Propensity score matching analysis was used to perform selective 1:2 ratio matching of the 43 patients undergoing the modified maze procedure with 86 patients undergoing CSM. Early operative outcomes were analysed for differences. The absence of AF recurrence without the use of anti-arrhythmic drugs was calculated at 2 years by a generalised linear model analysis.One (1.1%) early death occurred in the CSM group, and no deaths occurred in the modified maze group (p=0.722). The aortic cross-clamp durations were 76.30±8.86 minutes for the modified maze and 92.38±10.88 for the CSM procedure (p<0.001). There were no late strokes or deaths during the 2-year follow-up. The modified maze group showed similar rates of absence of AF without the use of anti-arrhythmic drugs as the CSM group within the 2 years (p=0.332).This modified maze simplifies the "cut-and-sew" procedure and reduces operating time while retaining the efficacy of CSM.