Current results of minimally invasive surgical ablation for isolated atrial fibrillation

The Cox maze surgical ablation operation is a highly effective treatment for patients with atrial fibrillation, but adoption has been limited by procedure complexity and invasiveness. Minimally invasive approaches using nonsternotomy limited access and eliminating cardiopulmonary bypass have been developed. All published series of minimally invasive surgical ablation for isolated, atrial fibrillation were reviewed. Series were analyzed for method of access, energy source, procedure success, and complications. Outcomes were compiled based on type of atrial fibrillation, method and length of follow-up, and freedom from atrial fibrillation with and without antiarrhythmic drugs. There are 14 published series with outcomes reported in 604 unique patients. Most procedures are performed through bilateral minithoracotomies with video assistance, although in later series a totally thoracoscopic approach is more commonly used. Bipolar radiofrequency is the predominant energy source used, and bilateral pulmonary vein isolation the most common lesion set, with some reports adding ganglionic plexi ablation and more extensive ablation lines. Approximately 53% of the procedures were performed for paroxysmal and 47% for persistent/long-standing persistent atrial fibrillation. Overall freedom from atrial fibrillation at 6-12 months is 84% (59%-91%), with 89% (79%-100%) in paroxysmal and 62% (25%-87%) in persistent/long-standing persistent patients. Overall freedom from atrial fibrillation off of antiarrhythmic drugs is 65% (57%-87%). Results approximating those of the Cox maze procedure are achieved with minimally invasive surgical ablation of atrial fibrillation in patients with paroxysmal atrial fibrillation. Further developments are necessary to further simplify and standardize the procedure, to replicate the results in larger series from more centers, to standardize the reporting of results, and to define a more effective procedure for persistent and long-standing persistent atrial fibrillation.