OBJECTIVE : Transmural thermal injury (TTI), such as esophageal erosion/ulcer and periesophageal nerve injury leading to gastric hypomotility, is not rare complications associated with pulmonary vein isolation (PVI). However, the mechanism and predicting factors of TTI have not yet been fully elucidated with second-generation cryoballoon (CB) PVI. METHODS : One hundred ten consecutive patients, who underwent CB PVI for atrial fibrillation and received esophagogastroduodenoscopy 2 days later, were investigated. The relationships between TTI and both clinical and anatomical parameters were examined. We measured the following parameters based on the computed tomography data: the angle of the left atrial (LA) posterior wall to the descending aorta (Ao) (LA-Ao angle); the branching angle of the left inferior pulmonary vein (LIPV) to the coronal plane (LIPV angle); and the minimum distance between the LA posterior wall and descending Ao enclosing the esophagus (LA-Ao distance). RESULTS : TTIs occurred in 19 patients (esophageal erosion in 2 and gastric hypomotility in 17). The patients with TTI were significantly older than those without TTI. In the anatomical parameters, the LIPV angle was larger and the LA-Ao distance was shorter in the TTI (+) group compared to the TTI (-) group. With the multivariate logistic regression analysis, the age (odds ratio [OR] 2.148, P = 0.022) and LA-Ao distance (OR 0.430, P = 0.013) were independent predictors of TTI. CONCLUSIONS : The occurrence of TTI in CB PVI was associated with aging, suggesting compromised periesophageal circulation, and the anatomical proximities between the LA and the descending Ao, which enclose the esophagus.