New endoscopic classification of esophageal mucosa in achalasia: A predictor for submucosal fibrosis.

Background/Aim: In this study, we aim to investigate the predicting ability of one new endoscopic classification of esophageal mucosa in achalasia (EMIA) for submucosal fibrosis (SMF) affecting the success of peroral endoscopic myotomy (POEM). Patients and Methods: The endoscopic and clinical data of achalasia patients undergoing POEM from 2012 to 2016 were investigated retrospectively. According to the endoscopic images or videos, EMIA and SMF grades were recorded. The relation between EMIA and SMF gradings was assessed by Spearman's rank correlation, and the predictive factors of SMF were identified by logistic regression analysis. Results: A total of 568 achalasia patients who underwent POEM were enrolled. For EMIA classification, there were 40 (7.0%), 373 (65.7%), 139 (24.5%), 14 (2.5%), 1 (0.2%), and 1 (0.2%) case (s) for grades a, b, c, d, e1, and f4, respectively. POEM procedures were aborted in 16 patients, and 93.8% (15/16) were due to severe SMF. Because grades e and f were rare and the related SMF was obvious, these two grading cases were excluded from the following analysis. Correlation between EMIA and SMF gradings was significant (Spearman r = 0.62, P < 0.01). Multivariate logistic analysis, including age, sex, disease duration, Ling classification, previous treatment, and EMIA classification, demonstrated that the EMIA classification (grades c to d) was an independent predictor for advanced SMF (odds ratio = 26.547, 95% confidence interval: 15.809-44.578, P < 0.01). Conclusions: The new endoscopic EMIA classification is an independent predictor of advanced SMF during POEM. The classification may be used for assessment of the difficulty and success of POEM.