Tip-in Endoscopic Mucosal Resection for 15- to 25-mm Colorectal Adenomas: A Single-Center, Randomized Controlled Trial (STAR Trial)

One-piece endoscopic mucosal resection (EMR) for lesions >15 mm is still unsatisfactory, and attempted 1-piece EMR for lesions >25 mm can increase perforation risk. Therefore, modifications to ensure 1-piece EMR of 15- to 25-mm lesions would be beneficial. The aim of this study was to investigate whether Tip-in EMR, which anchors the snare tip within the submucosal layer, increases en bloc resection for 15- to 25-mm colorectal lesions compared with EMR.In this prospective randomized controlled trial, patients with nonpolypoid colorectal neoplasms of 15-25 mm in size were recruited and randomly assigned in a 1:1 ratio to undergo Tip-in EMR or standard EMR, stratified by age, sex, tumor size category, and tumor location. The primary endpoint was the odds ratio of en bloc resection adjusted by location and size category. Adverse events and procedure time were also evaluated.We analyzed 41 lesions in the Tip-in EMR group and 41 lesions in the EMR group. En bloc resection was achieved in 37 (90.2%) patients undergoing Tip-in EMR and 30 (73.1%) who had EMR. The adjusted odds ratio of en bloc resection in Tip-in EMR vs EMR was 3.46 (95% confidence interval: 1.06-13.6, P = 0.040). The Tip-in EMR and EMR groups did not differ significantly in adverse event rates (0% vs 4.8%) or median procedure times (7 vs 5 minutes).In this single-center randomized controlled trial, we found that Tip-in EMR significantly improved the en bloc resection rate for nonpolypoid lesions 15-25 mm in size, with no increase in adverse events or procedure time.