OBJECTIVE:Although minimally invasive approaches for surgical treatment of stand-alone atrial fibrillation have gained popularity for the past decade, ablation technology and extensive lesion sets play a major role in the achievement of a successful procedure, especially in presence of persistent and long-standing persistent atrial fibrillation. We evaluated clinical outcomes after totally endoscopic biatrial epicardial ablation of persistent atrial fibrillation with a novel integrated uni-bipolar radiofrequency device.METHODS:Forty-nine (49) consecutive patients with stand-alone atrial fibrillation underwent right-sided monolateral thoracoscopic surgical ablation with a novel integrated uni-bipolar radiofrequency energy delivery and temperature-controlled technology. Atrial fibrillation was persistent in 13 (26.5%) of 49 and long-standing persistent in 36 (73.5%) of 49 patients. Mean ± SD age was 60.6 ± 10.3 years. Median duration of atrial fibrillation was 74 months. Mean ± SD left atrial diameter was 44.7 ± 4.0 mm.RESULTS:Epicardial en bloc isolation of all pulmonary veins (box lesion) and additional ablation of the right atrial free wall was successfully performed via minimally invasive approach without any intraoperative and postoperative major complications. Intraoperative entrance and exit block was achieved in 77.5% (38/49) and 91.8% (45/49) of patients, respectively. Mean ± SD ablation time was 16.3 ± 4.8 minutes. No intensive care unit stay was required. Postoperative sinus rhythm was achieved in 93.8% (30/32) patients, and no pacemaker implantation was required. At 13 months, 87.7% (43/49) of patients were in sinus rhythm; 71.4% (35/49) were free from antiarrhythmic drugs and 75.5% (37/49) from oral anticoagulation.CONCLUSIONS:Integrated uni-bipolar radiofrequency ablation technology showed to be effective for the surgical treatment of atrial fibrillation with a total endoscopic approach. A versapolar suction device with extensive right-left atrial lesion set may further improve outcomes in patients with nonparoxysmal atrial fibrillation.

The HISTORIC-AF trial is a prospective, multicentre, single-arm study designed to evaluate the outcomes of a staged endoscopic and transcatheter ablation in patients with stand-alone, persistent or long-standing persistent atrial fibrillation (AF). From 2012 to 2015, 100 consecutive patients were enrolled and underwent thoracoscopic left atrial epicardial isolation ('box lesion') followed by transcatheter ablation in case of AF recurrency. The safety end point was the composite outcome of freedom from major adverse events at 30-days, while efficacy end points were: (i) primary: freedom from AF and stable sinus rhythm following isolated thoracospic ablation > 60% and (ii) secondary: freedom from AF and stable sinus rhythm > 80% following hybrid ablation (as per HRS criteria). No death occurred and surgical thoracoscopic procedure was successfully completed in all patients. Survival free from major adverse events at 30 days was 94%: there were 3 permanent pacemaker implants, 2 episodes of stroke and 1 revision for bleeding. At discharge, 87% of patients were in sinus rhythm. A staged transcatheter ablation was carried out in all patients with AF recurrences at the end of 3 months blanking period (17% of patients). At 12-months follow-up, a stable restoration of sinus rhythm was achieved in 75% and 88% of patients following isolated thoracoscopic ablation and hybrid ablation, respectively. The HISTORIC-AF trial showed that thoracoscopic isolated surgical ablation reached both the safety and the efficacy end points. Hybrid ablation steadily improved rhythm outcomes and may be considered in the future as the treatment of choice for patients with persistent and long-standing persistent AF. NCT01622907.