The full bi-atrial lesion pattern in the Cox-maze procedure: a concept rather than a technique.

Abstract

I have carefully read the article by Sharples et al. [1], in which they compared in a randomized controlled trial atrial fibrillation (AF) surgery versus no AF surgery in a population undergoing planned cardiac surgery with or without concomitant AF surgery, respectively. In this trial, the authors reported that AF surgery significantly increased the possibility to remain in sinus rhythm (SR) at 5 years [odds ratio (OR) = 2.98; 95% confidence interval (CI) 1.23–7.17, P = 0.015]. Also, the composite of survival free of stroke and AF was better in the AF surgery group (OR = 2.34, 95% CI 1.03–5.31). However, the net rate of freedom from AF at 5-year follow-up must be painstakingly analysed in this study. At 5 years of follow-up, only 38.7% of the AF surgical group versus 22.4% of the alone group (P = 0.043) were in SR. Unfortunately, these figures are too low to be accepted in our daily practice. Therefore, the enthusiasm for the apparent good results of this trial must be tempered with caution, so that consequent confusions are avoided. Under these conditions, it makes more sense to examine the basic principles and rationale of the Cox-maze procedure in an effort to guide our decisions. Based on the fact that several macro-reentrant circuits have been identified in both atria as responsible for sustaining AF, Dr. James L. Cox set the basis for the development of the Cox-maze procedure consistent with a full bi-atrial lesion pattern [2]. Despite several iterations, the final aim with the Cox-maze procedure is to preserve as much as possible the original lesion pattern as originally described including appropriate lesions in both atria [2]. In fact, all the other lesser procedures have been shown to be less effective in eliminating AF in the long term.