The effectiveness of colonoscopy in reducing colorectal cancer mortality relies on the detection and removal of neoplastic polyps. Because the risk of prevalent cancer and of transition to cancer increases with polyp size, effective and safe resection of large polyps is particularly important. Large polyps ≥20mm are removed by so-called endoscopic mucosal resection (EMR) using electrocautery snares. Resection of these large polyps is associated with a risk of severe complications that may require hospitalization and additional interventions. The most common risk is delayed bleeding which is observed in approximately 2-9% of patients. A recent retrospective study suggests that closure of the large mucosal defect after resection may decrease the risk of delayed bleeding. However, significant uncertainty remains about the polypectomy techniques to optimizing resection and minimizing risk. Important aspects that may affect risk include clipping of the mucosal defect and electrocautery setting.
Aim 1. The primary aim of the study is to compare the rate of delayed bleeding complications in patients undergoing endoscopic resection of large polyps between:
A) Closing the mucosal defect after resection (Clip group) and B) Not closing the mucosal defect after resection (No clip group).
Aim 2. The secondary aim of the study is to compare the rate of overall complications in patients undergoing endoscopic resection of large polyps between two cautery settings:
Any patient ≥18 and ≤89 who presents for a colonoscopy and who does not have criteria for exclusion Patients with a ≥20mm non-pedunculated colon polyp
Exclusion Criteria:
Patients with known (biopsy proven) invasive carcinoma in a potential study polyp Pedunculated polyps (as defined by Paris Classification type Ip or Isp) Patients with ulcerated depressed lesions (as defined by Paris Classification type III) Patients with inflammatory bowel disease Patients who are receiving an emergency colonoscopy Poor general health (ASA class>3) Patients with coagulopathy with an elevated INR ≥1.5, or platelets <50 Poor bowel preparation Pregnancy
