Hybrid Epicardial and Endocardial Ablation of Atrial Fibrillation: Is Ablation on Two Sides of the Atrial Wall Better Than One?

Evolution of Surgical Ablation of Atrial Fibrillation T he success of catheter ablation of atrial fibrillation has continued to increase with the introduction of new technology, additional experience, and advances in our understanding of the targets of ablation. Nevertheless, patients with symptomatic drug refractory long-standing atrial fibrillation present a particular challenge for treatment with catheter ablation techniques. The so-called “cut-and-sew” surgical maze procedure was developed by the pioneering work of James Cox to treat this patient population. This procedure was subsequently modified to reduce the complexity and time required and is embodied in the Cox-Maze-IV surgery, which is performed on cardiopulmonary bypass and uses a combination of radiofrequency ablation, cryoablation, and surgical incisions. The next step in the evolution of the procedure was the replacement of the cryoablation lesions and the surgical incisions with radiofrequency ablation alone. This step obviates the need for cardiopulmonary bypass and created an epicardial-only technique. The evolution of epicardial ablation tools created the ability to access portions of the left atrium either through mini-thoracotomies or using thoracoscopic tools. These tools were designed to address several challenges including obtaining safe access around the pulmonary veins. Currently most procedures use a bipolar clamp-like device to ablate around the antral portion of the left atrium just proximal to the pulmonary veins on each side. Completion of the box lesion requires use of an epicardial-only tool to create the roof and floor lines. Results of a Thoracoscopic Based Surgical Ablation Procedure