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.