Background: Atrial fibrillation is the most common form of arrhythmia leading to hospital admission. Over 2.2 million Americans are affected by atrial fibrillation and approximately 160,000 new cases are identified annually. As the population continues to age, the number of patients will increase. AF is an incremental risk factor for death and stroke, and consumes billions of dollars in health care expenditures.
Methods: Between August 2003 and October 2004, 50 drug-resistant, symptomatic atrial fibrillation patients underwent thoracoscopic or robotic-assisted off-pump epicardial microwave ablation with the FLEX 10 device (Guidant, Indianapolis, IN). There were 35 men (70.0%) and 15 women (30.0%), mean age 59.1 years +/- 10.0 (range, 37-75 years). Mean duration of atrial fibrillation was 73.5 months +/- 82.3 (range, 5-480 months). Thirty-three patients (66.0%) had intermittent atrial fibrillation and 17 (34.0%) continuous. Intermittent patients had pulmonary vein isolation whereas continuous patients had additional right and left atrial lesions performed. Forty-six patients (92.0%) had endoscopic stapling of the left atrial appendage.
Results: There were no hospital deaths. Postoperative in-hospital complications were minimal with 2 patients (4.0%) experiencing diaphragmatic dysfunction. No patient required a permanent pacemaker implant. Mean postoperative length of stay was 3.7 +/- 2.2 days. Cumulative follow-up was 335.8 patient months, mean 7.6 months (range, 2.0-15.9 months). There was 1 late death (2.0%). In 5 patients (10.0%) the MicroMaze operation and subsequent electrophysiology intervention failed and a Cox-Maze III operation was performed. Follow-up was 100% complete with 79.5% (35 of 44) patients in normal sinus rhythm.
Conclusions: Totally endoscopic closed-chest microwave ablation for treatment of intermittent and continuous atrial fibrillation is technically feasible and presents minimal risk to the patient. Initial results are impressive and demonstrate an enhanced quality of life and freedom from atrial fibrillation in drug-resistant symptomatic patients.