Advanced endoscopic resection methods are recommended for removing rectal neuroendocrine tumors (NETs) < 10 mm, but there is no consensus on optimal endoscopic technique. This study aimed to determine whether endoscopic mucosal resection with ligation (EMR-L) is superior to endoscopic submucosal dissection (ESD) in terms of efficacy and safety, focusing on achieving adequate vertical margin distance.

This dual-center cohort study included consecutive patients with rectal NETs ≤ 10 mm. Adequate vertical margins were exploratively defined as a margin distance exceeding 115 μm, the 25th percentile threshold. Propensity score matching (PSM) was applied to compare outcomes between EMR-L and ESD.

The study included 204 rectal NETs from 186 patients, with 61 lesions in each group after PSM. Compared with ESD, the EMR-L group demonstrated a higher R0 resection rate (98.4% vs. 83.6%, P = 0.021), a greater proportion of adequate vertical margins (80.3% vs. 62.3%, P = 0.030), and a lower rate of positive vertical margins (1.6% vs. 13.1%, P = 0.041). Subgroup analysis indicated that lesions ≤ 5 mm without prior biopsy or central depression derived greater benefit from EMR-L. Furthermore, EMR-L was associated with significantly shorter procedure times (median 5.0 vs. 19 minutes) and a markedly lower overall complication rate (8.2% vs. 29.5%, P = 0.005), particularly perforation (3.3% vs. 16.4%, P = 0.028).

EMR-L outperforms ESD for small rectal NETs by achieving higher R0 and better vertical margins in shorter times, while minimizing risk of perforation.

Received: 19 March 2025

Accepted after revision: 08 July 2025

Accepted Manuscript online:
14 July 2025

Article published online:
15 August 2025

© 2025. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial-License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes, or adapted, remixed, transformed or built upon. (https://creativecommons.org/licenses/by-nc-nd/4.0/).

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Bibliographical Record
Jianning Liu, Weihua Yu, Peng Liu, Hao Tian, Lihong Gan, Kaige Zhang, Hui Chen, Nian Fang. Optimal endoscopic resection method based on vertical margin distance for small rectal neuroendocrine tumors: Propensity score-matched study. Endosc Int Open 2025; 13: a26551320.
DOI: 10.1055/a-2655-1320