Depth of noninjecting resection using bipolar soft coagulation mode for 6 to 9 mm colorectal polyps: a retrospective study in Japan.

[BACKGROUND] Endoscopic resection of colorectal polyps reduces mortality from colorectal cancer. We report here a novel resection method, known as noninjecting resection using bipolar soft coagulation mode (NIRBS), and assess its feasibility. This study aimed to compare the resection depth achieved with NIRBS to those achieved with cold snare polypectomy (CSP) and conventional endoscopic mucosal resection (CEMR).

[METHODS] Patients with 6 to 9 mm colorectal polyps underwent endoscopic resection at Hoshigaoka Medical Center between October 2023 and January 2024. We analyzed the thickness of resected submucosal tissue following the use of NIRBS, CSP, and CEMR.

[RESULTS] We identified 95 polyps, including adenomas and serrated lesions. The proportions of specimens containing submucosal tissue were 21.4%, 100.0%, and 97.9% in CSP, CEMR, and NIRBS, respectively. The median submucosal tissue thickness for CEMR and NIRBS was 1,167 and 1,125 µm, respectively, which was significantly greater than 0 µm for CSP. For NIRBS, the median thickness was 1,140 and 1,017 µm for the expert and non-expert endoscopists, respectively.

[CONCLUSIONS] The depth of submucosal resection with NIRBS exceeded 1,000 μm regardless of endoscopist experience. NIRBS can be a useful resection method for patients with colorectal polyps, including those with non-submucosally invasive carcinomas.