Temporal Stability of the Esophageal Location by Computed Tomography Imaging in Patients Undergoing Repeat Catheter Ablation of Atrial Fibrillation Karuna Chilukuri, MD, Brian S. Caffo, PhD, Charles A. Henrikson, MD, Alan Cheng, MD, Fawaz Alhumaid, MD, Sunil Sinha, MD, David Spragg, MD, Ronald Berger, MD, PhD, Joseph E. Marine, MD, Hugh Calkins, MD and Saman Nazarian, MD Johns Hopkins Hospital, Baltimore, MD, Advocate Lutheran General Hospital, Park Ridge,IL INTRODUCTION: -Accurate identification of the course of the esophagus may reduce the risk of atrio-esophageal fistula in patients undergoing catheter ablation of atrial fibrillation (AF). -Reliance upon a pre-acquired image of the esophagus may lead to detrimental results if the esophageal / pulmonary vein (PV) relationship is not temporally stable. -This study evaluated the temporal stability of the location of the esophagus in patients undergoing repeat catheter ablation of AF. METHODS: -Thirty consecutive patients (age 58±8 years, 73% male, 63% paroxysmal) underwent repeat catheter ablation for AF with a mean of 11 ± 5 months after an initial AF ablation. -Cardiac computed tomography (CT) was performed in a 24 hour window prior to each ablation procedure. -A single investigator masked to patient identities performed CT image analysis. -Esophageal distance from each PVs (Figure 1), left atrium and spine was compared on consecutive CT images using the paired Student’s t-test. RESULTS: -As shown in Table 1,there was no statistically significant change in the esophageal distance to the PVs, posterior left atrium, and spine between the initial and repeat ablation procedures (p=NS). -The average mobility of the left superior pulmonary vein was 0.4 mm, left inferior pulmonary vein was 1.3 mm, right superior pulmonary vein was 1.7 mm and right inferior pulmonary vein was 1.8mm between the initial and repeat ablation procedures. Initial Ablation Repeat Ablation P Value Esophagus to LSPV (mm) 28±1428±130.8 Esophagus to LIPV (mm) 11±810±80.3 Esophagus to RSPV (mm) 24±1225±120.1 Esophagus to RIPV (mm) 9±1011±110.1 LA Volume (mm 3 )203±96211±680.7 Esophageal – LA contact (mm) 19±918±100.4 Esophagus – Spine (mm) 5±55±60.9 Table 1. Computed tomography evaluation of esophageal location at initial and repeat ablation procedure. LSPV = Left superior pulmonary vein, LIPV= Left inferior pulmonary vein, RSPV = Right superior pulmonary vein, RIPV = Right inferior pulmonary vein, LA = Left atrium Disclosures : None Figure 1. Distance between the esophagus and the ostia of left superior PV (1a), left inferior PV (1b), right superior PV(1c) and right inferior PV (1d) on standard axial images 1a 1b 1c 1d CONCLUSION: -The long-term location of the esophagus is stable relative to the pulmonary veins, posterior left atrium, and the spine. -Pre-acquired images of the esophagus can be used to guide ablation away from the esophagus. -Additionally, when an initial ablation attempt is limited by the position of the esophagus, the problem will likely recur at repeat procedures and an alternative treatment strategy may be needed a