Abstract
BACKGROUND Hybrid ablation (a combination of thoracoscopic epicardial ablation and catheter ablation) has become a new technique for atrial fibrillation treatment. OBJECTIVE The goal of this study was to evaluate the success and electrophysiological follow-up after using the COBRA Fusion device to deliver a circumferential lesion set anterior to the pulmonary veins in an attempt to isolate the posterior left atrium (box isolation).
METHODS Surgical ablation was carried out via a thoracoscopic approach using the COBRA Fusion radiofrequency catheter. An electrophysiology study was done 2-3 months later to verify box isolation (and to complete it, if needed) and to perform right-sided isthmus ablation.
Fat thickness along the presumed box lesion line was measured using preprocedural computed tomography. RESULTS Thirty patients (mean age 60.0 +/- 11.6 years; 22 men; 8 with long-standing persistent AF and 22 with persistent atrial fibrillation) were enrolled.
The duration of the EP study was 216.3 +/- 64.2 minutes. Box isolation, based on the EP study, was complete in 12 patients (40%) and incomplete in 18 patients (60%).
Successful box isolation was achieved with catheter ablation in 16 of 18 patients (89%). A total of 39 gaps in these 16 patients were identified.
Typical gap locations were the anterior superior part of the superior pulmonary veins and the roofline. Fat thickness along the roofline was substantially higher than that along the inferior line (4.58 +/- 1.61 mm vs 2.37 +/- 0.76 mm; P < .001).
CONCLUSION There is a relatively low rate of complete isolation using the COBRA catheter ablation system. The superior line and anterior parts of superior pulmonary veins have most conduction gaps.