Injury to the Muscle Layer and Risk of Non-cardiac Chest Pain after Endoscopic Submucosal Dissection for Esophageal Cancer

Background and aims: Non-cardiac chest pain (NCCP) is a frequent complication of endoscopic submucosal dissection (ESD) for early-stage esophageal cancer. However, little is known about relationships between ESD findings and NCCP. This study aims to evaluate the risk factors for NCCP, including ESD findings related to injury to the muscle layer. Methods: We enrolled a total of 296 lesions from 270 patients with esophageal squamous cell carcinoma (ESCC), who underwent ESD in our center. The grade of injury to the muscle layer caused by ESD was categorized as follows: grade 0: no exposure of muscularis propria; grade 1: muscularis propria exposure and/or whitish color change by the electrocoagulation; grade 2: torn muscularis propria with whitish color change by the electrocoagulation; and grade 3, esophageal perforation. The risk factors for NCCP, including ESD findings, were analyzed by univariate and multivariate analyses. Results: NCCP occurred in 89 patients (33.0%) after esophageal ESD. Multivariate analysis demonstrated that younger age [odds ratio (OR) 0.95, 95% confidence interval (95%CI) 0.92-0.98, p=0.003), postoperative fever (>= 38 degrees C) (OR=25.9, 95%CI: 2.89-232.10, p=0.004), ESD findings (grade 1: OR=3.99, 95%CI: 1.63-9.75, p=0.003 and grade 2: OR=3.18, 95%CI: 1.54-6.57, p=0.002) were independently associated with the incidence of post ESD NCCP. Conclusions: ESD findings relate to slight Injury to the muscle layer, such as muscularis propria exposure and whitish color change by the electrocoagulation were identified as risk factor for post ESD NCCP. We should therefore perform esophageal ESD carefully to avoid injuring the muscle layers.