Evaluation of the circumferential location of mild reflux esophagitis (Grade A and B) in the lower esophagus.

Background and Aim: Discrepancies have been reported in the circumferential locations of mild mucosal breaks. We investigated their locations using a new method. Methods: This is a retrospective study. Eighty patients (Grade A/B: 53/27) with mild mucosal breaks in the lower esophagus were examined. Since the 3 o'clock position corresponded to the right wall of the lower esophagus using our method with sufficient accuracy, the circumferential locations of mucosal breaks were identified as times on a clock face, which were changed to circular data to calculate the mean direction. The circumferential distribution of mucosal breaks was evaluated in the single lesion group (single group) and multiple lesion group (multiple group). Results: Forty-eight of 80 patients had 1 mucosal break, while 32 had ≥2 mucosal breaks. Circumferential locations markedly differed between the single and multiple groups. In the single group, mucosal breaks were exclusively distributed between 2 and 7 o'clock, with 50% in the 3 o'clock direction (right wall). In the multiple group, 81 mucosal breaks were distributed circumferentially, not uniformly; however, at least 1 lesion was located between 2 and 7 o'clock in 91% of subjects. Therefore, a factor for the development of mucosal breaks from the right to posterior wall was present in both groups. Conclusion: In the single group, mucosal breaks were localized from the right to posterior wall, mainly in the right wall. In the multiple group, mucosal breaks were located circumferentially, but often between the right lateral and posterior wall. These two distributions significantly differed.Clinical trial registration: This is a retrospective study, so it was not registered.