Circumferential submucosal incision prior to endoscopic mucosal resection versus conventional endoscopic mucosal resection for colorectal lesions with endoscopic features of sessile serrated lesions

Background and aims Sessile serrated lesions (SSLs) are more prone to incomplete resection than conventional adenomas. This study evaluated whether circumferential submucosal incision prior to endoscopic mucosal resection (CSI-EMR) can increase the rate of complete and en bloc resections of colorectal lesions with endoscopic features of SSL. Methods Retrospective analyses and propensity score matching were performed for the resection of colorectal lesions >= 10 mm with endoscopic features of SSL. Results After 1:1 ratio matching, 127 lesions in the CSI-EMR group and 127 in the EMR group were selected for analysis. The median size of the lesions was 15 mm (IQR 12-16) in both groups. There was no significant difference in either the complete resection rate or en bloc resection rate between CSI-EMR and EMR groups (96.9% vs. 92.9%, P = 0.155; 92.1% vs. 89.0%, P = 0.391). By contrast, the R0 resection rate was significantly higher in the CSI-EMR group than in the EMR group (89.8% vs. 59.8%, P < 0.001). The median procedure time was significantly longer in the CSI-EMR group than in the EMR group (6.28 min vs. 2.55 min, P < 0.001), whereas there was no significant difference between the two groups in the incidence of adverse events or recurrence rate. Multivariate analysis showed that CSI-EMR was the only factor significantly associated with R0 resection (P < 0.001). Conclusions For colorectal lesions with endoscopic features of SSL, CSI-EMR does not increase the complete or en bloc resection rate, but does increase the R0 resection rate. The procedure time is longer for CSI-EMR than EMR. The association of CSI-EMR with R0 resection and non-recurrence should be further evaluated.