Esophageal Contour Changes during Cryoablation of Atrial Fibrillation

Abstract

BACKGROUND: We have observed contour changes of the barium-filled esophagus during atrial fibrillation (AF) ablation with cryo-energy delivered in direct proximity to the esophagus. OBJECTIVE: To evaluate the frequency, location, and severity of esophageal contour changes during cryo-energy application close to the esophagus. METHODS: We retrospectively analyzed cine-fluoroscopic images acquired during hybrid cryo-radiofrequency AF ablation in 100 consecutive patients with cryo-energy delivered only in direct proximity to the esophagus. RESULTS: Esophageal contour changes were observed in 28 (32%) of 89 patients (and 74 [6.2%] of 1,191 of all cryo applications). They were more frequent in the left common pulmonary vein (PV) (50%) and less so in the right common PV and the upper PVs (4-5%). The distance of the ablation catheter from the endoesophageal contour prior to cryo-energy applications associated with contour changes was 1.8 +/- 1.5 mm, which increased to 4.1 +/- 1.6 mm at the time of peak contour change (P < 0.001). The esophageal contour deformation was 2.3 +/- 0.9 mm. There were no apparent complications related to cryo-energy application for 3-4 minutes, even if associated with contour changes. CONCLUSION: Esophageal contour changes were observed in >6% of cryo applications in direct proximity to the esophagus (32% of patients) and were most frequent in the posterior aspect of the left common and right lower PV ostium when cryo-energy was delivered at a distance of <or=5 mm from the esophageal contrast silhouette. No overt esophageal injury occurred. However, the safety of cryo-energy application in direct proximity to the esophagus remains to be further confirmed.