Underwater Endoscopic Mucosal Resection Versus Metal Clips With Hot Snare Polypectomy for Resection of Big Pedunculated Colorectal Polyps：a Randomized Controlled Trial

Endoscopic resection of pedicled polyps mainly focuses on how to prevent bleeding, and also needs to pay attention to the convenience of resection and the integrity of resection, which means that different endoscopic resection strategies should be adopted for pedicled polyps with different pedicle sizes. The head larger than 20mm or pedicle larger than 5mm are defined as large pedicle polyps, which are at greater risk of bleeding. Current guidelines recommend hot removal by snare following preoperative saline injection, ligation of the pedicle with a nylon ring or metal clip, depending on the size of the polyp head and pedicle. However, the use of snares and metal clamps does not appear to reduce delayed postoperative bleeding, and the technical requirements of nylon ligation are relatively high. Recent studies have found that Underwater endoscopic mucosal resection (UEMR) is also safe and effective for the treatment of large and medium colorectal stemless polyps. Therefore, it is still necessary to further explore new safe and effective endoscopic resection strategies and techniques.