Optimal Resection Technique for Medium-sized (10-20mm) Colorectal Polyps

This study will investigate which resection technique (Endoscopic Mucosal Resection (EMR), cold EMR, or underwater EMR) leads to lower recurrence rates and less adverse events in patients with colorectal polyps (10-20mm).

Endoscopic resection of colorectal polyps has previously been demonstrated to lower the incidence of colorectal cancer, a major cause of cancer-related mortality globally. By disrupting the progression of adenomas into carcinomas, polypectomy is essential in effectively lowering colorectal cancer mortality. There is currently a surplus of high-quality research on the best ways to remove large polyps (\>20mm). For colorectal polyps of 10 to 20 mm, however, the best endoscopic resection method is unknown. Due to the lack of a standard polypectomy technique for the complete removal of medium-sized colorectal polyps, clinicians use a variety of methods according to their preferences and local resources. The historic gold standard of treatment for resecting polyps greater than 10 mm is hot endoscopic mucosal resection (EMR). The term "hot" refers to the use of electrocautery to cut through dense mucosal tissue, ablate remaining marginal dysplastic tissue, and prevent rapid bleeding through thermal vascular coagulation. However, adverse events such as perforation, prolonged bleeding, and post-polypectomy syndrome are all linked to electrocautery-induced damage. In contrast, cold snare polypectomy (CSP) and cold electrocautery minimal resection with injection (C-EMR-I) are alternative well-established techniques for the removal of polyps smaller than 10 mm, demonstrated to be associated with less delayed adverse effects than EMR. Underwater EMR (U-EMR), a novel technique developed in the last decade wherein water is instilled into the colon, allowing for submucosal fat to rise, elevating the lesion, and allowing mucosal resection in the absence of submucosal injectate. U-EMR may achieving higher en bloc resection rates, R0 resection rates, and lower recurrence rates. There are no specific recommendations for EMR of medium-sized polyps from gastroenterological and endoscopic societies globally.

The aim of this randomized control study is to compare the polyp recurrence rates and adverse events between cold snare EMR (C-EMR), hot EMR (H-EMR) and underwater EMR (U-EMR) for colorectal polyps in the size of 10-20mm.

Eligibility Criteria:
Inclusion Criteria:

1. The patient (or a legally authorized representative) provides informed consent
2. 18 years of age or older
3. Completion of the endoscopist-recommended bowel preparation
4. Presence of one eligible medium-sized polyp:

   * 10-20 mm in size
   * Paris classification of 0-IIa (flat, elevated lesion) on standard white light colonoscopy
   * JNET Type 1 or 2A on magnifying Narrow Band Imaging (NBI) suspecting a sessile serrated lesion, adenoma, or adenoma with low-grade dysplasia.

Exclusion Criteria:

1. Patient \< 18 years old
2. Inability to provide informed consent
3. Inflammatory Bowel Disease,
4. Familial Polyposis
5. Pregnancy
6. Incomplete bowel preparation
7. Patients with ineligible lesion:

   * Paris classification of 0-Ip or 0-Is on standard white light colonoscopy,
   * JNET Type 1 suspecting a hyperplastic polyp, or Type 2B or 3 suspecting a high- grade dysplasia or adenocarcinoma.