Previously Attempted Large Nonpedunculated Colorectal Polyps Are Effectively Managed by Endoscopic Mucosal Resection

Area of Science:

• Gastroenterology
• Endoscopic Surgery
• Colorectal Cancer Prevention

Background:

• Endoscopic mucosal resection (EMR) is a standard treatment for large nonpedunculated colorectal polyps (LNPCPs).
• Optimal EMR strategies for previously attempted LNPCPs (PA-LNPCPs) remain unclear compared to naive LNPCPs (N-LNPCPs).

Purpose of the Study:

• To evaluate the efficacy and safety of EMR for PA-LNPCPs.
• To compare EMR outcomes between PA-LNPCPs and N-LNPCPs.

Main Methods:

• A prospective observational cohort study included LNPCPs ≥20 mm treated with EMR.
• Efficacy assessed by technical success and recurrence at first surveillance colonoscopy (SC1).
• Safety evaluated by intraprocedural and post-EMR bleeding, and perforation.

Main Results:

• EMR achieved 93.0% technical success for PA-LNPCPs, increasing to 95.6% with 2-stage resections.
• Recurrence occurred in 7.8% of PA-LNPCPs; margin thermal ablation at SC1 reduced recurrence (0% vs 18.0%).
• No significant differences in technical success or recurrence were found between PA-LNPCPs and N-LNPCPs after adjusting for 2-stage EMR.

Conclusions:

• EMR, with auxiliary techniques, demonstrates high technical success and low recurrence for PA-LNPCPs.
• Adjunctive thermal ablation at surveillance colonoscopy may further reduce recurrence in PA-LNPCPs.