Improving complete EMR of colorectal neoplasia: A randomized trial comparing snares and injectate in the resection of large sessile colon polyps

Background: There are few randomized studies examining efficacy of snares and agents in EMR. Objective: To compare the use of a combined needle and snare unit with injectate versus a spiral wire and injectate (primary);saline solution versus hydroxypropyl methylcellulose (secondary). Design: Prospective, randomized, factorial, single center. Setting: Tertiary-care academic medical center. Patients: A total of 140 patients with large (>15 mm), sessile, colorectal polyps. Interventions: Polyps randomized to either 1 of 2 snare types and 1 of 2 injectates. Main Outcome Measurements: Primary - the Sydney resection quotient (SRQ), defined as the size of the polyp divided by the number of pieces resected and the amount of tissue per snare attempt. Secondary - procedure time, adverse events, residual neoplasia at follow-up. Results: The SRQ was higher with thecombined unit (median 13.8 mm vs 7.1 mm; P = .019); additionally, procedure time was less (median 6 vs 11 minutes; P < .001). Resection was considered complete after the EMR in 62% (42/68) with the combined needle and snare unit versus 51% (37/72; P = .22) with the spiral wire. Rates of adverse events were similar. Residual neoplasia was found at follow-up in 22% (10/46) with thecombined needle and snare unit versus 21% (10/48; P = .89) with the spiral wire. There was no evidence of differences in outcomes by lifting agent. Limitations: The SRQ is only a surrogate marker. Conclusion: This study provides evidence that the integrated needle-snare may be superior to the snare alone for the removal of large, flat polyps. Additionally, the type of injectate appears to have no impact on outcome.