Purpose: 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.
Methods: 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.
Results: 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).
Conclusion: 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.