Impact of margin thermal treatment after EMR of giant (≥40 mm) colorectal lateral spreading lesions

Increasing lesion size is a risk factor for recurrence after piecemeal EMR (pEMR). Snare-tip soft coagulation (STSC) treatment of the normal-appearing margin after pEMR of lesions ≥ 20 mm has been shown to reduce recurrence rates by 75% to 80%. We sought to evaluate the impact of STSC on giant (≥ 40 mm) lateral spreading lesions treated by pEMR. We describe the relative risk and absolute risks of recurrence with and without STSC margin treatment after EMR of ≥ 40-mm lesions.We performed a retrospective evaluation of a prospectively collected database on large lesions describing lesion size, location, and methods of resection. We excluded lesions < 40 mm in maximum dimension, those that did not undergo follow-up care at our center, and those in which argon plasma coagulation was used for either ablative treatment of residual polyp or margin treatment. Propensity score analysis was used to account for potential differences between patients treated with and without STSC.There were 68 lesions ≥ 40 mm removed by pEMR without STSC treatment and 133 removed and treated with STSC. There were no differences between groups in demographics, polyp size, location, histologic features, and mean follow-up time. The recurrence rate in the no-treatment group was 35% versus 9% with STSC (P < .00001 by direct comparison and P = .008 by using the propensity score analysis).STSC treatment after pEMR of large lateral spreading lesions in the colorectum reduced recurrences by 75%. However, the absolute recurrence rate of 9% remained clinically significant in the STSC-treated group. Short-term follow-up care after STSC of lesions ≥ 40 mm is still warranted, and additional study of technical factors that eliminate recurrence after pEMR of giant lateral spreading lesions is warranted.