The Five-Box Thoracoscopic Maze Procedure

Purpose. Comprehensive treatment of atrial fibrillation requires both compartmentalization of the posterior left atrium and connecting ablations to the mitral annulus to interrupt perimitral macro reentry and to isolate the arrhythmogenic left atrial substrate. We present a new procedure that compartmentalizes virtually all arrhythmogenic anatomy etiologic in atrial fibrillation, enabling simple verification by demonstration of bidirectional block. Description. Through a totally thoracoscopic approach, complete dissection of the transverse sinus and exposure of the left atrial floor enables the creation of contiguous compartments connecting to the anterior mitral trigone and isolating the posterior left atrium. The result is a comprehensive electrophysiologic replication of the Cox Maze left atrial lesion pattern. Evaluation. Each compartment is verified in real time using bidirectional block with a probe placed on the untreated atrium inside the compartment. Conclusions. Interruption of perimitral macro reentry in two perpendicularly oriented planes in a totally thoracoscopic procedure results in an operation with efficacy approximating the Cox Maze benchmark. (Ann Thorac Surg 2010; 90: 986 -90) (C) 2010 by The Society of Thoracic Surgeons