Atrial Fibrillation Ablation with Esophageal Cooling with a Cooled Water‐Irrigated Intraesophageal Balloon: A Pilot Study

Introduction: A left atrioesophageal fistula is an uncommon but devastating complication that may occur during atrial fibrillation (AF) ablation, and may be due to thermal injury occurring during the radiofrequency (RF) ablation. We examined the feasibility of an esophageal cooling (ECO) method using a cooled water‐irrigated intraesophageal balloon (IB). Methods and Results: Eight patients with drug‐refractory AF underwent RF catheter ablation to encircle the ipsilateral pulmonary veins. During the RF ablation at the posterior left atrium, the esophageal lumen was cooled using a 9‐Fr. IB catheter with a balloon length of 40 mm and diameter of 10 mm, in which cooled water, with a water temperature of 4.5 ± 3.1 °C, was irrigated while the luminal esophageal temperature (LET) was measured with an intraesophageal probe placed at a site close to the tip of the ablation catheter. In the control, the LET increased from 36.4 ± 0.8 °C to 40.5 ± 1.7 °C within 26.1 ± 8.2 seconds during 3.9 ± 1.2 RF energy applications, whereas with the ECO the LET decreased to 30.2 ± 2.9 °C at baseline (P<0.01 vs control), and increased only to 33.5 ± 2.9 °C (P<0.01 vs control) at most, within 30 seconds during 3.9 ± 1.2 RF energy applications. All pulmonary veins were successfully isolated in all patients without any complications. During a follow‐up period of 3.1 ± 1.2 months, no esophageal injuries were observed and all but one patient have been free from any symptoms. Conclusions: Use of an IB successfully lowers LET. This might have the potential of preventing esophageal injury, although further study is required.