Introduction/objective: Piecemeal endoscopic mucosal resection is a safe and effective procedure for the management of large non-pedunculated colorectal polyps. Its major limitation is the possibility of residual or recurrent adenoma and the consequent need for scheduled surveillance colonoscopies, with the implied burden for the patient and health systems. We aimed to evaluate if the Size/Morphology/Site/Access (SMSA) and Sydney EMR Recurrence Tool (SERT) scores are effective in predicting residual/recurrent adenoma after piecemeal endoscopic resection of large non-pedunculated colorectal polyps.
Methods: Prospective observational cohort study of piecemeal endoscopic mucosal resection of large non-pedunculated colonic polyps performed in a tertiary center. SMSA and SERT scores were calculated in the index colonoscopy and evaluated regarding the ability to predict residual/recurrent adenoma.
Results: One hundred fifty-eight procedures were included. Lesions mean size was 31.6 ± 10.1 mm. 65.8% were flat and 61.4% were located in the right colon. Residual/recurrent adenoma was present in 17 (10.8%) cases. SMSA 2 and SERT 0 lesions had 0.0% and 5.7% of residual/recurrent adenoma rate at 6 months, respectively, while SMSA 3-4 and SERT 1-4 lesions had a 11.5% and 14.8% rate, respectively, at 6 months. SMSA grade 2 and SERT grade 0 had a negative predictive value of 100% and 94%, respectively, for residual/recurrent adenoma. SMSA score had an area under the receiver-operating characteristics curve of 0.732 (P = 0.003), while SERT score had a value of 0.730 (P = 0.002) for residual/recurrent adenoma.
Conclusion: SMSA and SERT scores are effective tools to identify lesions with a low risk of residual/recurrent adenoma.