Abstract 2322: Limiting Esophageal Temperature in Pulmonary Vein Isolation Reduces Esophageal Damage
Introduction: Left atrial esophageal fistula due to thermal injury of the esophagus is a rare but devastating complication after pulmonary vein isolation (PVI). Common means of prevention are: Reduction of power at the posterior wall and visualization of the esophagus. Esophageal injury after radiofrequency ablation is believed to be a precursor of fistula formation and reported to occur in 2,9% to 47%.
Methods: PVI was performed in 106 consecutive patients with paroxysmal or persistent (27patients) atrial fibrillation. Extraostial ablation was accomplished using an open irrigated tip catheter and either the CARTO (Biosense Webster) or Ensite NavX (SJM) system.
Generator settings: 48°C, 40W (posterior wall 30W), flow 30ml/min. An MRI or CT image was integrated in the anatomical map prior to ablation. An esophageal temperature probe (Fiab, Esotherm) with 3 thermocouples (distance 10mm) was introduced into the esophagus. Special consideration was taken to assure a close distance between the thermocouples and the tip of the ablation catheter either by fluoroscopy (CARTO) or by using the NavX system. A cut-off intraluminal esophageal temperature of 40°C was defined for termination of energy delivery. After temperature normalization ablation was continued with less power (20W or 15W) and/or an alternative ablation course was chosen to prevent further temperature rise. All patients underwent endoscopy the next day.
Results: In 97 of 106 patients the cut-off temperature of 40°C was reached. A temperature overshoot was observed in 91 patients; mean Tmax 41.3±1.3 °C. The maximal registered temperature was 45°C. Only one of 106 patients (0.9%) experienced thermal injury of the esophagus (erosion). The Tmax in this patient was 41.1°C. No fistula formation occurred.
Conclusion: In contrast to previous reports of PVI without temperature monitoring, limiting esophageal temperature in radiofrequency PVI results in a very low incidence (0.9%) of asymptomatic esophageal damage as evidenced by endoscopy. Esophageal temperature rise and overshoot after cessation of energy delivery is a frequent phenomenon in PVI. Further studies are needed to evaluate the benefit of the defined temperature cut-off in preventing fistula formation.