An interventional study of Prophylactic defect closure and No prophylactic defect closure in Colorectal Cancer and Polyp of Colon, sponsored by Centre hospitalier de l'Université de Montréal (CHUM). Recruiting at 1 site in Canada. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-09-08.
Sponsored by Centre hospitalier de l'Université de Montréal (CHUM) · Not applicable, Interventional, and Prevention
The goal of this clinical trial is to compare adverse even rates after EMR for large (≥20mm) flat colorectal polyps (so-called laterally spreading lesions, LSLs) when performing complete or no defect closure. It will also evaluate lesion recurrence after EMR for large colorectal LSLs.
The hypothesis is that performing complete defect closure following EMR of large colorectal LSLs will result in lower rates of adverse events compared to cases where no defect closure is performed.
For participants with planned EMR, endoscopists will perform EMRs as per standard of care and:
This trial is an open-label, two-arm, parallel-group, multicenter, randomized controlled superiority trial. Patients undergoing EMR will be randomized in a 1:1 ratio and assigned to undergo no closure (control group) vs complete defect closure (experimental group).
Participants with planned EMR procedures will be approached by a research assistant before the EMR to request study participation. To mitigate loss to follow-up, patients will be questioned on their preferred contact method with multiple contact methods obtained to adequately reach patients. The importance of follow-up after EMR to detect and treat recurrence will also be highlighted both verbally and in the consent forms during initial patient contact.
Despite being experienced, all endoscopist participants will review dedicated teaching videos showing the standardized EMR approach. Videos demonstrating key technical details defect closure will also be circulated across sites to ensure a standardized approach for both procedures as described in the literature.
- Control group: EMR will be performed as per standard of care with submucosal injection and electrocautery resection of all visually visible polyp tissue using a snare. After performing EMR with thermal ablation, prophylactic defect closure will not be performed. Endoscopists can chose to close defects if there are significant concerns for risk of perforation or active perforation after EMR. When the endoscopist determines that the resection is complete, a tattoo will be placed 3 cm distal to the resected lesion to allow for better identification of the resection site in case of follow-up colonoscopy for delayed bleeding. If multiple large polyps are found and removed, the largest lesion (study polyp) will be marked with two tattoos 3 cm distal and 3 cm proximal to the lesion, to clearly identify the study polyp resection site.
- Experimental group: EMR will be performed as per standard of care with submucosal injection and electrocautery resection of all visually visible polyp tissue using a snare.
After performing EMR with thermal ablation, prophylactic defect closure will be performed. The choice of the number and types of closure devices used to achieve defect closure will be left to endoscopist discretion. If multiple large polyps are found and removed, the largest lesion (study polyp) will be marked with two tattoos 3 cm distal and 3 cm proximal to the lesion, to clearly identify the study polyp resection site. As per standard of care, endoscopists will take a photograph of the lesion before resection for documentation; a photograph of the EMR resection site will be taken before and after defect closure; a photograph of the defect will be taken if emergency colonoscopy is performed to treat delayed bleeding. When more than one lesion meeting inclusion criteria is present in a patient, all lesions 20mm or larger will be photographed next to an open snare to aid in size measurement.
- 6-month \& 18-month follow-up colonoscopies: To mitigate loss to follow-up, patients will be questioned on their preferred contact method with multiple contact methods obtained to adequately reach patients. The importance of follow-up after EMR to detect and treat recurrence will also be highlighted both verbally and in the consent forms during initial patient contact. Patients will be sent a reminder that they will soon receive an invitation to undergo follow-up through their preferred contact method. If patients do not undergo follow-up after invitation, a research assistant will contact patients by phone to answer any concerns they might have at that time.
At follow-up colonoscopies, endoscopists will identify the resection scar tangential to the tattoo placed at the initial EMR. The resection scars will be observed under white light and digital chromoendoscopy to assess for visual recurrence. For all patients, four random biopsies will be taken at the resection scar. If visual recurrence is present, the lesions will be resected using the method deemed most appropriate by the endoscopist at the time and pathologically evaluated for histologic recurrence.
6,541 studies on the registry are indexed under Colorectal Neoplasms; 1,667 are open to participants now.
This study's planned enrollment of 686 is above the median of 76 across 4,800 interventional studies indexed under Colorectal Neoplasms.
Browse Colorectal Neoplasms studies →Centre hospitalier de l'Université de Montréal (CHUM) is the lead sponsor of 376 studies on the registry; 110 are open to participants now.
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Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
The anaesthetists’ scale of health before surgery: I is healthy, II has a mild illness that is under control, III a severe one, IV a severe illness that is a constant threat to life. V and VI are used for the critically ill and for organ donors.
Blood tests of how long blood takes to clot. The INR is the prothrombin time (PT) put on a common scale; about 1 is usual for someone not taking a blood thinner.
Criteria often make an exception for people on a blood thinner such as warfarin, whose INR is raised on purpose.
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ASA physical status
The anaesthetists’ scale of health before surgery: I is healthy, II has a mild illness that is under control, III a severe one, IV a severe illness that is a constant threat to life. V and VI are used for the critically ill and for organ donors.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
INR, PT and aPTT (clotting tests)
Blood tests of how long blood takes to clot. The INR is the prothrombin time (PT) put on a common scale; about 1 is usual for someone not taking a blood thinner.
Criteria often make an exception for people on a blood thinner such as warfarin, whose INR is raised on purpose.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Platelets
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Prophylactic defect closure will be performed using at least one new generation closure device.
After performing EMR with thermal ablation, prophylactic defect closure will not be performed.
Procedure: No prophylactic defect closure
Endoscopists will use at least one new generation closure device to approximate the healthy mucosal surrounding the submucosal defect to ensure complete defect closure. Adequate apposition of the mucosal defect margins will be achieved when no visible submucosal areas \>3 mm along the closure line are present.
After performing EMR with thermal ablation, prophylactic defect closure will not be performed.
Delayed bleeding
Defined as blood per rectum resulting in emergency room visit, unplanned hospitalization; endoscopic, radiologic, or surgical intervention.
Time frame: 14 days
Delayed perforation
Defined as endoscopic or radiologic evidence of air or luminal contents outside the gastrointestinal tract
Time frame: 14 days
Any delayed bleeding
Defined as blood per rectum after the procedure
Time frame: 14 days
Clinically significant delayed bleeding in the proximal colon
Defined as proximal to the splenic flexure
Time frame: 14 days
Clinically significant delayed bleeding in the distal colon
The distal colon is defined as splenic flexure and distal
Time frame: 14 days
Lesion recurrence
Lesion recurrence at 6 months' follow-up defined by pathology-confirmed hyperplastic, serrated or adenomatous histology at the tattooed resection site
Time frame: 6 months
Defect closure time
Time for defect closure
Time frame: 14 days
Technical success for complete defect closure
Defined as adequate apposition of the mucosal defect margins without visible submucosal areas \>3 mm along the closure line
Time frame: 6 months
Procedure costs
Costs associated with procedures
Time frame: 18 months
Technical success of margin and/or base ablation
Defined as achieving a complete uninterrupted ring of circumferential margin ablation for margin ablation, and achieving 100% surface ablation of the resection base for base ablation
Time frame: 18 months
Colonoscopies required to achieve lesion clearance
Defined as no histologic recurrence at the resection scar on follow-up
Time frame: 18 months
EMR procedure time
Duration of the EMR procedure
Time frame: During procedure
Margin and/or base ablation time
Duration of the margin and/or base ablation
Time frame: During procedure
Loss to follow-up
Number of patients lost to follow-up
Time frame: 18 months
Plan to share: Yes — Individual participant data that underlie the results reported in this article, after deidentification (text, tables, figures and appendices).
Supporting information: Study protocol, Statistical analysis plan, Informed consent form, Clinical study report, Analytic code
Time frame: Beginning 12 months and ending 36 months following article publication.
Access criteria: Proposals should be directed to daniel.von.renteln.med@ssss.gouv.qc.ca . To gain access, data requestors will need to sign a data access agreement
No publications or documents are linked to this record.
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