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.

Study Overview

• Status: Completed
• Conditions: Colon Polyps
• Intervention / Treatment: Procedure: Clip closure

Detailed Description

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.

• Study Type: Interventional
• Enrollment (Actual): 928
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Vermont
    • White River Junction, Vermont, United States, 05009
      • White River Junction VAMC

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 14 years to 85 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Clip closure + EndoCut; Clipping of the mucosal defect after resection of a ≥20mm non-pedunculated study polyp using clips. Resection is done using the EndoCut electrocautery mode.	Procedure: Clip closure; 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.
Active Comparator: Clip closure + Coagulation; Clipping of the mucosal defect after resection of a ≥20mm non-pedunculated study polyp using clips. Resection is done using the Coagulation electrocautery mode.	Procedure: Clip closure; 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.
No Intervention: No clip closure + EndoCut; No clipping of the mucosal defect after resection of a ≥20mm non-pedunculated study polyp. Resection is done using the EndoCut electrocautery mode.
No Intervention: No clip closure + Coagulation; No clipping of the mucosal defect after resection of a ≥20mm non-pedunculated study polyp. Resection is done using the Coagulation electrocautery mode.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of Participants With Delayed Bleeding Complications	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.	30 days following a study polyp resection

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The Overall Number of Complications	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.	30 days
Complete Study Polyp Resection Rate	Rate of complete study polyp resection at the initial colonoscopy and at first follow-up endoscopy	6 months
Polyp Recurrence Rate	Rate of recurrent polyp at the resection site after complete polyp resection.	3 months to 5 years
The Number of Complications Associated With Clip Use	Incidence of complications associated with application of clips.	30 days

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Measured Factors Associated With Resection Complications	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.	30 days
Measured Factors Associated With Incomplete Resection or Recurrence of Polyps	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.	5 years

Collaborators and Investigators

• Sponsor: White River Junction Veterans Affairs Medical Center
• Collaborators: Dartmouth College; Boston Scientific Corporation
• Investigators: Study Chair: Heiko Pohl, White River Junction VAMC, Geisel School of Medicine at Dartmouth

Publications and helpful links

General Publications

• 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.

Study record dates

Study Major Dates

• Study Start (Actual): April 1, 2013
• Primary Completion (Actual): June 30, 2018
• Study Completion (Actual): October 1, 2022

Study Registration Dates

• First Submitted: September 3, 2013
• First Submitted That Met QC Criteria: September 5, 2013
• First Posted (Estimated): September 6, 2013

Study Record Updates

• Last Update Posted (Actual): July 12, 2024
• Last Update Submitted That Met QC Criteria: June 17, 2024
• Last Verified: June 1, 2024

More Information

Terms related to this study

• Keywords: Colonoscopy; Endoscopic mucosal resection; Colon cancer screening; Large colon polyps; Polyp resection
• Additional Relevant MeSH Terms: Pathological Conditions, Anatomical; Intestinal Polyps; Polyps; Colonic Polyps
• Other Study ID Numbers: CPHS-23578