Pulmonary vein isolation using a compliant endoscopic laser balloon ablation system in a swine model.

INTRODUCTION: The incidence of pulmonary vein reconnection and recurrent atrial fibrillation after a single catheter ablation procedure is unacceptably high. We studied the ability of a novel endoscopic laser balloon ablation system (EAS) to achieve acute and chronic pulmonary vein (PV) isolation in a swine model.
METHODS: Eight swine underwent EAS ablation and two underwent standard radiofrequency ablation for comparison. In the EAS arm, laser energy was delivered under visual guidance around the PV antrum in overlapping 30-degree arcs. In the standard ablation arm, radiofrequency energy was delivered via a 4-mm-tip catheter. PV isolation was confirmed acutely after 30 min, and reassessed after 4-6 weeks. Animals were then sacrificed for histopathologic analysis of the PVs.
RESULTS: For the EAS animals, 44 ± 10 overlapping lesions were required to achieve acute RSPV isolation. Chronic PV isolation was documented with the circular mapping catheter a mean of 28 ± 9 days after ablation in 7/8 animals (83%). In the standard ablation arm, 30 ± 3 RF lesions were delivered to achieve acute PV isolation. There was evidence of PV reconnection in both animals during the chronic study. Histologically, completely transmural circumferential lesions were found in 7/8 EAS animals, with 99% circumferentiality in the remaining animal. Both control RF animals had evidence of gaps, with isolation of 90% and 75% of the targeted PV segments, respectively.
CONCLUSION: Visually guided laser ablation using light energy via a compliant balloon catheter is feasible and achieved chronic isolation in 83% of targeted PVs.