Traction Devices May Not Affect the Vertical Margin Distance in the Endoscopic Submucosal Dissection of Rectal Neuroendocrine Tumors

Abstract

Introduction The usefulness of traction devices (TDs) in endoscopic submucosal dissection (ESD) for rectal neuroendocrine tumors (NETs) has not been reported. The aim of this study was to investigate the impact of using a TD on the vertical margin (VM) distance in the ESD of rectal NETs. Methods In this single-center, retrospective study, we included patients with rectal NETs who were treated with ESD during 2013-2023. They were divided into TD and non-TD groups. One pathologist remeasured the VM distance (primary outcome) and the depth of submucosal invasion (SM depth). Secondary outcomes were margins, resection time, delayed bleeding, and perforation. First, we performed propensity score matching (PSM) to assess the usefulness of TD for VM distance. Then, we used multiple regression analysis to identify factors affecting the VM distance. Results The TD and non-TD groups comprised 24 and 117 lesions, respectively. Patients in the TD group were significantly younger than those in the non-TD group (P = 0.003). In the TD and non-TD groups, the VM distance was 150 μm and 100 μm, respectively (P = 0.70). Only resection time significantly differed between groups, shorter in the TD group (P = 0.005). Twenty-two cases in each group were matched after PSM, yielding no significant differences in VM distance. The use of a TD was not an independent predictor of VM distance (P = 0.65), but age (P < 0.001) and SM depth (P = 0.003) were. Conclusion Using a TD does not seem to affect the VM distance in ESD for rectal NETs.

Keywords: endoscopic submucosal dissection; neuroendocrine tumor; rectum; traction device; vertical margin.

Figure 1. The vertical margin distance and submucosal invasion depth measurements displayed with hematoxylin-eosin staining.

The yellow dotted line indicates the lower edge of muscularis mucosa. The red dotted line indicates the invasion deepest point.

Figure 2. Endoscopic submucosal dissection with a multi-loop traction device.

(a) Neuroendocrine tumor in the rectum (9 mm in diameter) in the Rb location. (b) Marker dots placed around the lesion. (c) Full circumferential incision before dissection. (d) Traction using a multi-loop traction device. (e) Dissection with the multi-loop traction device. (f) Ulcer after endoscopic submucosal dissection.