Atrioesophageal fistula formation with cryoballoon ablation is most commonly related to the left inferior pulmonary vein

BACKGROUND Collateral damage has been reported with use of the cryoballoon for pulmonary vein isolation. OBJECTIVE The purpose of this study was to determine the incidence and characteristics associated with atrioesophageal fistula (AEF) after cryoballoon use. METHODS Cases of AEF reported with use of the cryoballoon since 2011 were collected from the Manufacturer and User Facility Device Experience (MAUDE) database, publications, and the manufacturer's database. Lowest balloon temperatures were compared with matched control patients undergoing cryoballoon ablation without AEF formation. Location of AEF was compared with AEF associated with radiofrequency ablation. RESULTS A total of 11 cases of AEF were identified from a worldwide experience that exceed 120,000 cases. Mean age was 60 (range 31-78 years), and 80% of patients were male. Although mean lowest balloon temperatures were no different between patients with AEF and those with no AEF (-58.5 degrees C +/- 7.2 degrees C vs - 56 degrees C +/- 2.6 degrees C, P = NS), balloon inflation times were longer in patients with AEF (238.8 +/- 54.8 seconds vs 178.1 +/- 37.5 seconds in the non-AEF group, P <=.001) All cases of AEF for which location was identified occurred in relation to the left pulmonary veins. The left inferior pulmonary vein (LIPV) was involved in 8 of 10 patients with cryoballoon compared to 0 of 11 patients in the radiofrequency group (P <.05). Mortality for cryoballoon-associated AEF was 64%. CONCLUSION AEF after cryoballoon use is rare ( <1 in 10,000) and most commonly was identified near the LIPV. Proximity of the esophagus to the LIPV and evidence of esophageal luminal cooling should be considered indications to limit cryoablation at this vein.