Concomitant Cox-Maze IV techniques during mitral valve surgery.

Atrial fibrillation (AF) is present in approximately 30% of patients presenting for mitral valve (MV) surgery (1). The addition of a concomitant surgical ablation procedure is indicated in patients that are either (I) symptomatic from their AF or (II) asymptomatic when the addition of a surgical ablation procedure can be performed with minimal risk (2). Surgical ablation of AF in patients undergoing concomitant MV procedure is not only successful at restoring sinus rhythm, but has also has been shown to decrease late stroke rates (3,4). The Cox-Maze procedure is the gold-standard procedure used in the surgical treatment of AF. The latest iteration, the Cox-Maze IV (CMIV), makes use of a combination of bipolar radiofrequency (RF) ablation and cryoablation. The use of ablation devices to replace the surgical incisions has simplified the procedure, which is helpful in the setting of a concomitant MV procedure since it adds little to the cardiopulmonary bypass (CPB) and cross-clamp times. Furthermore, both CMIV and MV procedures can be performed through either a sternotomy or less invasive right mini-thoracotomy (RMT) approach. In our experience, the use of the minimally invasive approach has significantly decreased morbidity and length-of-stay with similar efficacy in restoring normal sinus rhythm (Figure 1) (4,5). Figure 1 Freedom from atrial fibrillation and antiarrhythmic medications is shown at the 1-year follow-up for patients undergoing a Cox-Maze IV (CMIV, gray bars) procedure or a combined CMIV and mitral valve (MV, black bars) procedure (4). The completion of a CMIV procedure should precede the MV procedure. CPB and an arrested heart provide the ideal milieu for ablation and allows for reliable creation of transmural lesions. This article will focus on several key points which should be addressed during the CMIV procedure in order to avoid complications.