Background: Maze with a "Box lesion" around pulmonary veins (PV) is the gold standard procedure. Recently, we changed our technique of surgical ablation of atrial fibrillation (AF) from standard bilateral epicardial PV isolation to "Box lesion"
Methods: Between March 2009 and October 2011 we performed AF ablation in 163 patients by the "Box" technique around the PV, using only a cryo device in 90 patients and bipolar RF device with cryo ablator in 73 patients. Patients were 63±11 years of age. 104 (64%) patients had persistent and 20 (12%) long-standing persistent AF; "Box" was made by connecting left atriotomy to the base of amputated left atrial appendage with two lines along transverse and oblique sinuses by epi- and endocardial application of a bipolar RF device or with cryo probe application. Left atrial isthmus was ablated by cryoprobe.
Results: No complications were related to the ablation. Follow up mortality was 3(2%) patients. Mean follow up was 19±16 months. The follow up was performed by electro-physiologists and surgeons. Sinus rhythm was found in 95%, 87%, and 91% of patients at 6 month, 1, and 2 years after the ablation correspondently. 80%, 85%, and 85% of patients was free from antiarrhythmic medications at 6 month, 1, and 2 years after the ablation correspondently.
Conclusions: "Box lesion" is easy to perform and provides excellent freedom from AF We can explain it by better transmurality achieved by applying bipolar RF ablator only on one layer of atrial wall in contrary to epicardial PV isolation.
