Computed tomographic analysis of the esophagus, left atrium, and pulmonary veins: implications for catheter ablation of atrial fibrillation

The aim of this study was to investigate the anatomic relationship around the left atrium (LA) and to provide clinical information to help avoid the risk of an atrio-esophageal fistula during atrial fibrillation (AF) ablation. The multidetector spiral computed tomography images of 77 male patients (mean age, 54 +/- 9 years) with drug-refractory AF and 37 male control subjects (mean age, 50 +/- 11 years) were analyzed. We measured the following variables: (1) distance between the ostia of the pulmonary veins (PVs) and the ipsilateral esophageal border, (2) presence of a pericardial fat pad around each PV, and (3) contact width/length and presence of a fat pad between the LA and the esophagus. The distance between the esophagus and the ostia of right superior PV, right inferior PV (RIPV), left superior PV, and left inferior PV (LIPV) was 27.2 +/- 9.4 mm, 22.9 +/- 10.3 mm, 2.7 +/- 9.4 mm, and 7.1 +/- 8.8 mm, respectively. A fat pad between the esophagus and the superior PV was present in more than 90% of the subjects in both groups. However, the fat pad around inferior PV was present less frequently in the patients than in the control group (p = 0.011, RIPV; p < 0.001, LIPV). The average length of the LA-esophagus contact in the patients and the control group subjects was 26.2 +/- 10.4 and 18.5 +/- 5.1 mm, respectively (p < 0.001). Caution should be exercised when ablating the LIPV because the esophagus is located in close proximity to the left-sided PV and most of the inferior PVs in patients with AF are not covered with fat pads.