Immediate results of underwater endoscopic mucosal resection (uEMR) of epithelial neoplasms of the colon in inpatient and outpatient settings

Background. Endoscopic removal of epithelial neoplasms of the colon remains the primary method for the prevention of colorectal cancer. The underwater endoscopic resection technique (underwater EMR, uEMR), introduced in 2012, demonstrates several advantages over conventional EMR, including technical simplicity, higher completeness of resection, lower complication rates, and the possibility of outpatient performance. However, the method remains insufficiently studied in Russia, necessitating an evaluation of its effectiveness in domestic clinical practice. Objective. To evaluate the clinical outcomes of underwater endoscopic resection (uEMR) of epithelial neoplasms of the colon up to 50 mm in size in inpatient and outpatient settings. Material and methods. The study included 122 cases of patients who underwent underwater endoscopic resection of epithelial neoplasms of the colon between August 2023 and June 2025. The procedures were performed at the Department of Therapeutic and Diagnostic Endoscopy of University Clinical Hospital No. 2, Sechenov University. The main inclusion criteria were the benign nature of the lesion, the absence of signs of deep invasion, and a lesion size of up to 50 mm. We assessed resection completeness, procedure duration, complication rates, and recurrence. Results. The mean size of resected neoplasms was 15.6 mm, and the mean procedure time was 5.3 minutes. Complete resection was achieved in 94.5% of cases. Intraoperative and delayed complications were rare and clinically insignificant. The method demonstrated high efficacy and safety, including in outpatient settings. Conclusion. Underwater endoscopic resection (uEMR) proved to be an effective and safe technique for removing epithelial neoplasms of the colon. The findings support its broader implementation in routine endoscopic practice in both outpatient and inpatient settings.