Piecemeal endoscopic mucosal resection (p-EMR) remains widely used for large non-pedunculated colonic polyps when en‐bloc excision is not feasible. However, piecemeal resection is associated with a substantial risk of residual or recurrent adenoma due to fragmentation and incomplete resection. The 2024 ESGE guideline on colorectal polypectomy and EMR recommends that after hot-snare piecemeal EMR of large non-pedunculated colorectal polyps (LNPCPs), resection margins should undergo thermal ablation using snare-tip soft coagulation to decrease adenoma recurrence. In real-world practice, recurrence after EMR without margin ablation has been reported to reach 15–20%. Accordingly, reduction of recurrence - and the role of endoscopist expertise - remains critical for optimisation of patient outcomes. This study aimed to evaluate adenoma recurrence after piecemeal hot-snare resection in our center, and to assess the impact of prophylactic interventions (margin ablation and/or cold-snare margin resection) as well as endoscopist expertise.

We conducted a retrospective, single-center cohort study of all patients undergoing piecemeal hot-snare polypectomy or mucosectomy between January 2022 and December 2023 in a tertiary-care hospital. Lesions were classified based on the Paris Classification. We defined “experienced endoscopist” as one performing > 50 EMRs annually and/or having expertise in endoscopic submucosal dissection (ESD). We recorded whether prophylactic measures were applied after resection: margin thermal ablation and/or cold-snare margin resection. Descriptive statistics and appropriate comparative analyses were employed to explore associations between recurrence rates, the use of prophylactic measures, and endoscopist experience.

We resected 102 lesions in 102 patients. The median lesion size was 25 mm (range 10–50 mm); most lesions were located in the ascending colon (37.3%) or cecum (22.5%). The majority were Paris 0-IIa morphology (71.6%), including 45 granular and 8 non-granular LSTs. Prophylactic measures were applied in 66 cases (64.7%) - margin thermal ablation in 43, cold-snare margin resection in 9, and both in 14. Histopathology revealed 88 adenomas, 13 serrated lesions without dysplasia, and one with dysplasia. Of the 88 adenoma cases, 57 (64.8%) underwent surveillance colonoscopy at a mean of 8.7 months post-resection. Overall adenoma recurrence was observed in 19.3% of patients. With prophylactic measures, recurrence was 14%; notably, none of the patients in whom both techniques were used had recurrence, compared with 28% recurrence in the no-prophylaxis group — though this difference did not reach statistical significance. Recurrence was not associated with lesion size, location, or morphology. In contrast, procedures performed by an experienced endoscopist had a significantly lower recurrence rate (4% vs. 31.3%, p = 0.016). Within the prophylaxis subgroup, recurrence remained lower in the experienced endoscopist group, although the difference did not achieve statistical significance — likely due to limited sample size.

In our series, nearly one in five patients had adenoma recurrence after piecemeal resection, despite surveillance. Use of prophylactic measures (margin ablation and/or cold-snare margin resection) was associated with a lower recurrence rate, particularly when both techniques were applied. However, statistical significance was not reached, due to limited sample size and follow-up. Importantly, endoscopist expertise emerged as the most significant factor associated with decreased recurrence, underscoring the critical role of operator experience. These findings suggest that concentration of EMR in experienced hands may improve outcomes. Larger, adequately powered prospective studies are warranted to better define optimal prophylactic strategies, operator competency thresholds, and follow-up protocols.