Injury to the muscle layer, increasing the risk of post-colorectal endoscopic submucosal dissection electrocoagulation syndrome

Background and Aim: In colorectal endoscopic submucosal dissection (ESD), post-ESD electrocoagulation syndrome (PECS) has been recognized as one of the major complications. There are no reports on the relationships between ESD findings and PECS. This study aims to evaluate the risk factors for PECS, including ESD findings such as muscularis propria exposure. Methods: We performed a retrospective cohort study of patients who underwent colorectal ESD between January 2017 and December 2021 in Japan. 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; Grade 2, torn muscularis propria; and Grade 3, colon perforation. The risk factors for PECS, including injury to the muscle layer, were analyzed by univariate and multivariate analyses. Results: Out of 314 patients who underwent colorectal ESD, PECS occurred in 28 patients (8.9%). The multivariate analysis showed that female sex (odds ratio [OR] 3.233; 95% confidence interval [95% CI]: 1.264–8.265, P = 0.014), large specimen size (≥ 40 mm) (OR 6.138; 95% CI: 1.317–28.596, P = 0.021), long procedure time (≥ 90 min) (OR 2.664; 95% CI: 1.053–6.742, P = 0.039), and Grade 1 or 2 injury to the muscle layer (OR 3.850; 95% CI: 1.090–13.61, P = 0.036) were independent risk factors for PECS. Conclusions: Injury to the muscle layer, such as exposure or tear, was identified as a novel independent risk factor for PECS. We should perform colorectal ESD carefully to avoid injuring the muscle layers.