Minimally invasive surgical ablation of atrial fibrillation: The thoracoscopic box lesion approach

Atrial fibrillation is the most common cardiac rhythm disturbance and is associated with increased morbidity and mortality. It is often found in association with structural heart disease; however, lone atrial fibrillation is not uncommon. Potentially, these patients are ideal candidates for a minimally invasive thoracoscopic approach for the surgical treatment of atrial fibrillation.

From August 2003 through February 2006, 100 drug-resistant symptomatic patients with lone atrial fibrillation underwent thoracoscopic off-pump closed-chest epicardial ablation using the FLEX 10 AFx Microwave Ablation System (Guidant, Indianapolis, IN, USA). There were 66 men (66.0%) and 34 women (34.0%), with a mean age of 60.9 ± 9.8 (range 37–81) years. Mean duration of atrial fibrillation was 72.4 ± 79.5 (range 6–480) months. Sixty-four patients (64.0% had paroxysmal, 11 (11.0%) had persistent and 25 (25.0%) had permanent atrial fibrillation.

There were no hospital deaths. Postoperative in-hospital complications were minimal. Mean postoperative length of stay was 3.4 ± 1.7 days. Cumulative follow-up was 2,106.3 (mean 23.1) patient months, with a maximum follow-up of 39.8 months. There were three late deaths (3.0%). In nine patients (9.0%), the thoracoscopic box lesion pulmonary vein isolation operation and subsequent electrophysiological intervention failed, and a Cox-Maze operation was performed. Follow-up was 100% complete, with 42.0% (37 of 88) patients in normal sinus rhythm. Two patients (2.3%) experienced a transient ischemic attack and two (2.3%) a cerebral vascular accident. Twenty-seven patients (30.7%) required electrophysiological intervention post procedure. Ten patients (11.4%) were on amiodarone and 48 (54.5%) were on coumadin at follow-up.

Totally thoracoscopic surgical ablation for the treatment of atrial fibrillation is technically feasible and presents minimal risk to the patient. Clinical results with the application of microwave energy have been less than satisfactory, with no demonstrated electrical isolation of the pulmonary veins. Moreover, long-term relief from atrial fibrillation has not been achieved.