Clamping versus nonclamping thoracoscopic box ablation in long-standing persistent atrial fibrillation.

Abstract

To compare clinical outcomes of clamping devices and linear nonclamping devices for isolation of the posterior left atrium (box) in thoracoscopic ablation of long-standing persistent atrial fibrillation. Eighty patients who underwent thoracoscopic pulmonary vein and box isolation using a bipolar clamping device (42 patients) or bipolar nonclamping device (38 patients) to create the roof/inferior lesions for box isolation were included from 2 centers. Follow-up consisted of 24-hour Holter at regular intervals. Freedom from AF during 1-year follow-up and catheter repeat interventions were compared between groups. Acute intraoperative electrical isolation of the box compartment was significantly higher in the clamping group than in the nonclamping group (100% and 79%, respectively, P < .01). At 1-year follow-up, 91% of the clamping group and 79% of the nonclamping group were in sinus rhythm. During 1-year follow-up, recurrence rates did not significantly differ between the 2 groups (P = .08). Repeat catheter interventions were required in 10% of the clamping group and 21% of the nonclamping group (P = .15). Conduction gaps in the roof or inferior lesions were found in 1 patient (2%) in the clamping group versus 4 patients (11%) in the nonclamping group (P = .13). Thoracoscopic pulmonary vein and box isolation are highly effective in restoring sinus rhythm in long-standing persistent atrial fibrillation on short-term follow-up. Comparison of clamping and nonclamping devices revealed lower rates of intraoperative exit block of the box in the nonclamping group. However, this did not translate into a significant difference in atrial fibrillation freedom at short-term (1-year) follow-up.