Evaluation of a novel epicardial atrial fibrillation treatment system.

Abstract

PURPOSE: Surgical and catheter treatments for atrial fibrillation remain invasive or ineffective for most patients. A novel system developed to create epicardial ablation lesions during beating-heart surgical procedures was evaluated in an in vivo ovine model. DESCRIPTION: This novel ablation device integrates radiofrequency, suction, and perfusion to create transmural lesions by remaining consistently in contact with the irregular and curved surface of the beating heart. EVALUATION: Two epicardial ablation patterns were generated in five adult sheep: left atrial appendage and left pulmonary vein isolation. The 2-cm and 5-cm coagulation devices generated linear and curved lesions and maintained intimate contact against the epicardium using suction. Significant increases in bipolar pacing thresholds demonstrated trans-lesion conduction block in all animals. Histopathologic examination verified transmurality and showed changes normally observed after coagulation procedures. All lesions demonstrated mural degeneration throughout the lesion. No charring, vaporization, thromboembolic events, nor other complications were observed. CONCLUSIONS: This novel epicardial coagulation system successfully created continuous and transmural atrial lesions in a beating-heart ovine model.