Endoscopic Submucosal Dissection vs Endoscopic Mucosal Resection for Colorectal Polyps. A Meta-Analysis 

Background: This extensive meta-analysis sought to compare the surgical, histological, and oncological outcomes between endoscopic submucosal dissection (ESD) and endoscopic mucosal resection (EMR) in the treatment of colorectal polyps, with subgroup analysis comparing the efficacy of ESD and EMR between Japan and the rest of the world. Methods: : Embase and Medline databases were searched from inception to October 2020 in accordance with PRISMA guidelines for studies comparing en bloc , complete resection, margin involvement, resection time, need for additional surgery, complications, and recurrence rate of ESD with EMR. Results: : 281,344 colorectal polyps from 21 studies were included. When compared to EMR, the pooled analysis revealed ESD was associated with higher en bloc and complete resection rate, and lower lateral margin involvement and recurrence. ESD led to increased procedural time, need for additional surgery, and perforation risk. No significant difference in bleeding risk was found between the two groups. Meta-regression analysis suggested only right colonic polyps correlated with an increased perforation risk in ESD. Confounders including polyp size and invasion depth did not significantly influence the en bloc and complete resection rate, bleeding risk and recurrence. In subgroup analysis, Japan performed better than the rest of the world in both ESD and EMR with perforation risk of 4% and 0.0002%, respectively, as compared to perforation risk of 8% and 1%, respectively, in reports coming from rest of the world. Conclusions: : This meta-analysis demonstrated increased safety and efficacy of ESD and EMR done in Japan as compared with the rest of the world.