Safety of Endoscopic Resection of Large Colorectal Polyps: A Randomized Trial.

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: A) Low power coagulation and B) Endocut.

Large colon polyps, Polyp resection, Colon cancer screening, Colonoscopy, Endoscopic mucosal resection

Clipping of the mucosal defect after resection of a ≥20mm non-pedunculated study polyp using clips. Resection is done using the EndoCut electrocautery mode.

Clipping of the mucosal defect after resection of a ≥20mm non-pedunculated study polyp using clips. Resection is done using the Coagulation electrocautery mode.

No clipping of the mucosal defect after resection of a ≥20mm non-pedunculated study polyp. Resection is done using the EndoCut electrocautery mode.

No clipping of the mucosal defect after resection of a ≥20mm non-pedunculated study polyp. Resection is done using the Coagulation electrocautery mode.

Patients will be randomized to either closing the mucosal defect after polyp removal or not closing the mucosal defect using clips (main intervention and comparison). The resection margins will be approximated using clips. Complete closure is defined as approximated margins with less than 1cm gap between clips. All patients will further be randomized to two different settings of electrocautery (EndoCut or Coagulation) to standardize otherwise variable electrocautery practice, and for explorative analysis.

A bleeding event that occurred within 30 days after completion of the colonoscopy with a study polyp resection and is associated with a decrease in hemoglobin by at least 2gm, hemodynamic instability, presentation to the ED, need for hospitalization, repeat colonoscopy, or other interventions.

Overall complications are defined as an aggregate of all complications that occur at the time of the procedure (immediate complications) or during 30 days of follow-up. They include delayed bleeding complications, perforation, postpolypectomy syndrome, and clinical events that require an ED visit, admission to the hospital, additional testing or an intervention.

Factors that may be associated with complications, including electrocautery setting, polyp size, location of the polyp in the colon (right, left, rectum), histology, polyp morphology, time required for resection.

Factors that may be associated with incomplete resection may include prior attempts of removal, use of adjunctive argon plasma coagulation for residual polyp removal, polyp size, location, histology.

Inclusion Criteria: 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

Crockett SD, Khashab M, Rex DK, Grimm IS, Moyer MT, Rastogi A, Mackenzie TA, Pohl H; Large Polyp Study Group Consortium. Clip Closure Does Not Reduce Risk of Bleeding After Resection of Large Serrated Polyps: Results From a Randomized Trial. Clin Gastroenterol Hepatol. 2022 Aug;20(8):1757-1765.e4. doi: 10.1016/j.cgh.2021.12.036. Epub 2021 Dec 28.

Pohl H, Grimm IS, Moyer MT, Hasan MK, Pleskow D, Elmunzer BJ, Khashab MA, Sanaei O, Al-Kawas FH, Gordon SR, Mathew A, Levenick JM, Aslanian HR, Antaki F, von Renteln D, Crockett SD, Rastogi A, Gill JA, Law RJ, Elias PA, Pellise M, Mackenzie TA, Rex DK. Effects of Blended (Yellow) vs Forced Coagulation (Blue) Currents on Adverse Events, Complete Resection, or Polyp Recurrence After Polypectomy in a Large Randomized Trial. Gastroenterology. 2020 Jul;159(1):119-128.e2. doi: 10.1053/j.gastro.2020.03.014. Epub 2020 Mar 12.

Pohl H, Grimm IS, Moyer MT, Hasan MK, Pleskow D, Elmunzer BJ, Khashab MA, Sanaei O, Al-Kawas FH, Gordon SR, Mathew A, Levenick JM, Aslanian HR, Antaki F, von Renteln D, Crockett SD, Rastogi A, Gill JA, Law RJ, Elias PA, Pellise M, Wallace MB, Mackenzie TA, Rex DK. Clip Closure Prevents Bleeding After Endoscopic Resection of Large Colon Polyps in a Randomized Trial. Gastroenterology. 2019 Oct;157(4):977-984.e3. doi: 10.1053/j.gastro.2019.03.019. Epub 2019 Mar 15.