Comparison between ligation-assisted and precutting endoscopic mucosal resection for small rectal neuroendocrine tumors: a CHASID study

Background/Aims: Few studies have compared modified endoscopic mucosal resection (EMR) techniques for small rectal neuroendocrine tumors (NETs). This study evaluated the clinical outcomes of ligation-assisted EMR (EMR-L) and precutting EMR (EMR-P) for the treatment of small rectal NETs.Methods: We retrospectively reviewed patients who underwent EMR-L or EMR-P for rectal NETs ≤ 10 mm at four university hospitals between January 2018 and December 2022. Primary outcomes were en bloc resection and complete resection rates; secondary outcomes included procedural time and complications.Results: Among a total of 195 rectal NETs, 143 were resected using EMR-L and 52 using EMR-P. Although the histopathologically measured lesion size (4.0 ± 1.7 mm vs. 5.2 ± 2.4 mm, p = 0.002) was larger in the EMR-P group, the presence of ulcer or depression and lesion location did not significantly differ between the two groups. The en bloc resection rate (100.0% vs. 96.2%, p = 0.070) and complete resection rate (95.8% vs. 90.4%, p = 0.140) also were not significantly different. However, EMR-L had a significantly shorter procedure time (3.9 ± 2.3 min vs. 9.8 ± 5.6 min, p < 0.001). No significant differences were observed in procedure-related bleeding, perforation, recurrence, or hospital stay between the groups.Conclusions: Both EMR-L and EMR-P achieved high en bloc and complete resection rates with favorable safety profiles. However, EMR-L was significantly faster, suggesting that it is a more time-efficient approach for small rectal NET resection.