COLD SNARE PIECEMEAL ENDOSCOPIC MUCOSAL RESECTION (CSP-EMR) OF LARGE SESSILE COLONIC POLYPS ≥20 MM IS FEASIBLE, SAFE AND EFFECTIVE

Aims:

EMR is the standard therapy for resection of large (≥20 mm) non-malignant sessile colonic polyps. Serious adverse events are mostly due to electrocautery. This could be avoided by cold-snare-EMR. We hypothesized that aggressive wide field cold snare piecemeal EMR (CSP-EMR) could be as effective as conventional EMR, but with fewer adverse events. The study evaluated safety and efficacy of CSP-EMR for ≥20 mm sessile colonic polyps.

Methods:

All CSP-EMR cases performed by a single endoscopist (A.M.) at two academic hospitals for sessile polyps ≥20 mm, from Jan 2016-Dec 2017, were identified retrospectively. During this period, all lesions that were not suspicious for submucosal invasion, and were not very large Paris 0-Is lesions where cold snare resection would be technically very difficult, were performed by CSP-EMR. Efficacy was defined as the absence of residual or recurrent polyp during the first surveillance colonoscopy, which was assessed by rigorous endoscopic EMR scar examination and biopsies for histology. Clinically significant intra-procedural or delayed adverse events, histological outcomes and surveillance colonoscopy findings were assessed by reviewing medical records.

Results:

Tab. 1:

Results

Patients demographics:	Total no (n): 133	Male, n (%): 46 (31.1)	Female, n (%): 87 (68.9)	Median age (range): 67 years (21 – 88)
Polyp details:	Total no (n): 148	Size (mm) mean: 25.27	Size (mm) median: 20 mm	Range (mm): 20 – 60
Histology:	SSA/P without dysplasia n (%): 84 (56.8)	SSA/P with dysplasia n (%): 6 (4.1)	Adenomas with LGD, n (%): 50 (33.8%)	Adenomas with HGD, n (%): 2 (1.4%)
Surveillance:	Patients with follow up, n (%): 110 (82.7)	Polyps with follow up, n (%): 124 (83.8)	Recurrence, n (%): 4 (3.2)
Adverse events:	Intra-procedural bleeding treated with clips n (%): 2 (1.5)	Post-procedural bleeding settled spontaneously, n (%): 4 (3.0)	Abdominal pain settled spontaneously, n (%): 1 (0.8)	Perforation = 0 Post-polyectomy syndrome = 0

Conclusions:

CSP-EMR of sessile colonic polyps ≥20 mm is feasible and was at least as effective as conventional EMR, but with improved safety profile. We hypothesise that the enhanced safety of cold snaring allowed for an aggressive wide field resection that reduced recurrence rates. A randomised controlled trial or large prospective observational studies are required to more rigorously demonstrate non-inferiority and improved safety profile of CSP-EMR compared to conventional EMR, and to further determine which polyp morphologies are best suited to CSP-EMR.