An interventional study of Hybrid Argon Plasma Coagulation (h-APC) and Snare tip soft coagulation (STSC) 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 2026-09-18.
Sponsored by Centre hospitalier de l'Université de Montréal (CHUM) · Not applicable, Interventional, and Prevention
Large (≥20mm) colorectal polyps often harbor areas of advanced neoplasia, making them immediate colorectal cancer (CRC) precursors. Such polyps have to be completely removed to prevent CRC and to avoid surgery and/or adjuvant therapy. The laterally spreading lesions (LSLs) are removed via endoscopic mucosal resection (EMR). However, recurrence is common. New techniques for LSL resection (hybrid argon plasma coagulation (h-APC) margin and base ablation) have shown a reduction in recurrence following the interventions.
We hypothesize that performing hybrid argon plasma coagulation (h-APC) margin and base ablation during EMR of large (≥20mm) colorectal LSLs will lead to lower rates of lesion recurrence compared to Snare tip soft coagulation (STSC) margin ablation.
This trial is an open-label, two-arm, parallel-group, multicenter, randomized controlled superiority trial. Patients undergoing EMR will be randomly assigned in a 1:1 ratio to undergo additional STSC margin ablation (control group and current standard of care) or h-APC ablation of the margins and base (experimental group).
Patients will be enrolled in the study before the endoscopy procedure, or in the outpatient clinic.
Eligible patients who have consented to participate in the study will be asked to take a standard colonoscopy preparation regimen before their scheduled procedure.
EMR intervention will be performed for all eligible patients with a large laterally spreading lesions (LSLs) by expert endoscopists. Only if a polyp meets inclusion criteria, the study subject will be enrolled and randomized into one of these 2 groups:
The standard EMR technique will be used for the primary removal of all polyps. Submucosal injection will be used to lift the polyp from the muscularis propria. Injection will be used as per the current standard of care using a contrast agent and a lifting agent (e.g., NaCl 0.9% or Voluven). Snare electrocautery resection will be facilitated until complete visible removal of the complete polyp. Electrocautery snare technique will be facilitated using standard microprocessor-controlled electrocautery. If residual polyp tissue cannot be removed by a snare, other means such as cold snare (i.e., for small residual polyp tissue that cannot be engaged into standard snares) or avulsive methods will be used. Randomization will be performed after resection is complete and before thermal ablation. After the complete removal of the polyp, depending on the randomization group, h-APC or STSC techniques will be used for margin and base or only margin ablation of the post-EMR defect.
If multiple large polyps are found and removed, the study polyp will be marked with two tattoos 3 cm distal and 3 cm proximal to the lesion, to clearly identify the study polyp associated scar in the follow-up colonoscopy. Polyps will be sent to the pathology lab and evaluated according to standard practice by institutional pathologists. To determine the homogeneity and depth of h-APC margin ablation in the pathology lab, some ablated margins might be resected using the standard cold snare technique.
Telephone calls after 14 days following the EMR will be conducted to assess possible adverse events that occurred within the first 14 days after EMR.
Follow-up 1: Surveillance colonoscopy occurring 6 months after the EMR intervention for the assessment of recurrence (biopsy from the post-EMR site to be confirmed by pathology) following the intervention (h-APC) and the control (STSC) techniques.
Follow-up 2: Surveillance colonoscopy at 18 months (± 6 months) after the EMR intervention for the assessment of recurrence (biopsy from the post-EMR site to be confirmed by pathology) at FU1.
Patients with visible recurrence at the EMR site will undergo additional resection for complete eradication of recurrence. Patients with no visible but pathology-confirmed recurrence will be rescheduled for another colonoscopy with subsequent treatment of the post-EMR site and another follow-up colonoscopy for biopsies and confirmation of complete/incomplete eradication within 18 months after the initial EMR.
6,541 studies on the registry are indexed under Colorectal Neoplasms; 1,667 are open to participants now.
This study's planned enrollment of 892 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.
Counted across the registry records on this site, refreshed daily.
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.
A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.
Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.
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.
Biopsy and archival tissue
A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.
Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Standard endoscopic mucosal resection (EMR) technique will be used for the primary removal of all polyps, utilizing submucosal injection. Electrocautery snare technique will be facilitated using standard microprocessor-controlled electrocautery (e.g., ERBE VIO Endocut 3-1-6). Ablation of the margin and base of the polypectomy site will be performed using Hybrid Argon Plasma Coagulation (h-APC, Erbe Hybrid APC).
Procedure: Hybrid Argon Plasma Coagulation (h-APC)
Standard endoscopic mucosal resection (EMR) technique will be used for the primary removal of all polyps, utilizing submucosal injection. Electrocautery snare technique will be facilitated using standard microprocessor-controlled electrocautery (e.g., ERBE VIO Endocut 3-1-6). Ablation of the margin of the polypectomy site will be performed using Snare tip soft coagulation (STSC).
Procedure: Snare tip soft coagulation (STSC)
The hybrid argon plasma coagulation (h-APC) combines an ablation technique (APC) with the option for submucosal saline injection using a high-pressure water jet. The technique allows for the lifting of dysplastic epithelium, creating a cushion under the mucosa to facilitate the ablation of larger areas more thoroughly and with higher energy settings, while posing a low risk for side effects or complications.
Also known as: h-APC
The Snare tip soft coagulation (STSC) involves using a snare to remove polyps, while simultaneously applying soft coagulation to the surrounding tissue using a specialized tip on the snare.
Also known as: STSC
Recurrence after colorectal EMR between the h-APC and STSC methods
Lesion recurrence at first follow-up after EMR of large (≥20mm) colorectal LSLs when performing STSC margin ablation or h-APC margin and base ablation. Defined by visual recurrence or pathology-confirmed hyperplastic, serrated or adenomatous histology of the same histology of the index lesion at the tattooed resection site on at least one of four random biopsies of resection scars. These will be evaluated from an intention to treat and per protocol standpoint.
Time frame: 4 years
Adverse event rates after EMR with STSC or h-APC
Adverse event rates after EMR of large (≥20mm) colorectal LSLs when performing EMR with STSC margin ablation or h-APC margin and base ablation. Defined as either a) delayed bleeding (defined as blood per rectum resulting in emergency room visit, unplanned hospitalization; endoscopic, radiologic, or surgical intervention) or b) delayed perforation (defined as endoscopic or radiologic evidence of air or luminal contents outside the gastrointestinal tract). These will be evaluated from an intention to treat and per protocol standpoint.
Time frame: 4 years
Technical success of STSC or h-APC
Technical success of STSC or h-APC defined as achieving a complete uninterrupted ring ofcircumferential margin ablation for STSC and h-APC, without crossover to complete the margin ablation, and achieving 100% surface ablation of the resection base for h-APC.
Time frame: 4 years
Lesion recurrence at the 18-month follow-up after EMR with STSC or h-APC
Lesion recurrence at the 18-month follow-up after EMR with STSC or h-APC
Time frame: 4 years
High-grade dysplasia or colorectal cancer occurence after EMR during the 18-month follow-up period.
High-grade dysplasia or colorectal cancer occurence after EMR during the 18-month follow-up period at the resection site.
Time frame: 4 years
CRC occurrence during the 18-month follow-up period
CRC occurrence after EMR during the 18-month follow-up period
Time frame: 4 years
Colonoscopies required to achieve lesion clearance after EMR with STSC or h-APC
Colonoscopies required to achieve lesion clearance, defined as no histologic recurrence at the resection scar on follow-up.
Time frame: 4 years
EMR procedure time
EMR procedure time with STSC or h-APC
Time frame: 4 years
STSC or h-APC ablation time
Time frame: 4 years
Loss to follow-up
Time frame: 4 years
Intestinal preservation 18 months after ablation
Defined as no surgical resection performed.
Time frame: 4 years
Clinically significant delayed bleeding in the proximal colon after EMR with STSC or h-APC
Defined as blood per rectum resulting in emergency room visit, unplanned hospitalization; endoscopic, radiologic, or surgical intervention. Proximal defined as proximal to the splenic flexure.
Time frame: 14 days
Clinically significant delayed bleeding in the distal colon after EMR with STSC or h-APC
Defined as blood per rectum resulting in emergency room visit, unplanned hospitalization; endoscopic, radiologic, or surgical intervention. Distal defined as splenic flexure and distal.
Time frame: 14 days
Clinically significant delayed bleeding in the entire colon after EMR with STSC or h-APC
Defined as blood per rectum resulting in emergency room visit, unplanned hospitalization; endoscopic, radiologic, or surgical intervention.
Time frame: 14 days
Delayed perforation after EMR with STSC or h-APC
Delayed perforation defined as endoscopic or radiologic evidence of air or luminal contents outside the gastrointestinal tract
Time frame: 14 days
Any delayed bleeding after EMR
Any delayed bleeding after EMR, defined as blood per rectum after the procedure
Time frame: 14 days
Defect closure time
Time frame: 4 years
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: 4 years
Costs associated with procedures
Time frame: 4 years
Factors associated with recurrence after colorectal EMR between the h-APC and STSC methods
Lesion recurrence at first follow-up after EMR of large (≥20mm) colorectal LSLs when performing STSC margin ablation or h-APC margin and base ablation. Defined by pathology-confirmed hyperplastic, serrated or adenomatous histology of the same histology of the index lesion at the tattooed resection site on at least one of four random biopsies of resection scars. Factors such as age, sex, lesion size (20-29mm, ≥30mm; 20-39mm, ≥40mm), histology, location, difficulty (difficult defined as peri-appendiceal, on the ileocecal valve, resection previously attempted and failed by a referring endoscopist), use of epinephrine in submucosal injection, submucosal lifting solution, resection type (en bloc \[i.e. in one piece\] vs piecemeal), technical success, study site, endoscopist yearly EMR volume, presence of intraprocedural bleeding, utilization of adjunct resection methods, ileocecal or anus involvement, polyp histology/morphology will be evaluated.
Time frame: 4 years
Factors associated with adverse event rates after EMR with STSC or h-APC
Adverse event rates after EMR of large (≥20mm) colorectal LSLs when performing EMR with STSC margin ablation or h-APC margin and base ablation. Defined as either a) delayed bleeding (defined as blood per rectum resulting in emergency room visit, unplanned hospitalization; endoscopic, radiologic, or surgical intervention) or b) delayed perforation (defined as endoscopic or radiologic evidence of air or luminal contents outside the gastrointestinal tract). Factors such as age, sex, lesion size, morphology, histology, location, complete/incomplete/no defect closure, prophylactic vessel ablation, base ablation, anticoagulant use will be evaluated
Time frame: 30 days
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.
Started Jul 2024 (actual). Primary completion is estimated for Oct 2027, 38 months after the start.
Of 898 non-industry interventional studies with no phase under Colorectal Neoplasms, half reached primary completion within 32 months of starting (the median), counting those still running; a quarter within 15 and three quarters within 62. This study's planned 38 months is above that.
Counting every sponsor, half of 955 studies reached it within 32 months; a quarter within 14 and three quarters within 60.
How these figures are worked out, and which studies are left out of them.
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
No contact was published for this record. The registry link below has the sponsor’s details.
Get an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Centre hospitalier de l'Université de Montréal (CHUM) →