Efficacy and safety of ligation-assisted endoscopic submucosal resection combined with endoscopic ultrasonography for treatment of rectal neuroendocrine tumors

Objective Rectal neuroendocrine tumors (R-NETs) usually invade the submucosa, and so complete resection is difficult. The treatment of choice for R-NETs <= 10 mm in size is endoscopic resection, but there is still controversy concerning the best endoscopic method. This study evaluated the efficacy and safety of ligation-assisted endoscopic submucosal resection combined with endoscopic ultrasonography (ESMR-LUS) for treatment of R-NETs. Methods We retrospectively analyzed the data of 101 patients with R-NETs <= 10 mm in size who underwent ESMR-LUS (n = 48) or conventional ligation-assisted endoscopic submucosal resection (ESMR-L; n = 53) between May 2019 and September 2021 at the 900th Hospital of Joint Logistics Support Force. Complete resection rate, pathological complete resection rate, procedure time, and adverse events were compared between the two groups of patients. Results The endoscopic complete resection rate was slightly higher in the ESMR-LUS group than in the ESMR-L group (100 vs. 96.2%, p = .496). The pathological complete resection rate was also slightly higher in the ESMR-LUS group (97.9 vs. 88.7%, p = .152), these findings, though statistically non-significant, have practical clinical significance. Margin involvement was less common in ESMR-LUS patients than in ESMR-L patients (1 vs. 6). Involvement of the lateral resection margin was found one patient in the ESMR-LUS group versus two patients in the ESMR-L group, and deep resection margin involvement in no patient in the ESMR-LUS group versus four patients in the ESMR-L group. Mean procedure time was longer in the ESMR-LUS group than in the ESMR-L group (11.08 +/- 1.89 min vs. 9.38 +/- 2.09 min, p = .061). Immediate bleeding occurred in two patients in the ESMR-LUS group vs. seven patients in the ESMR-L group. Two patients in the ESMR-L group also suffered perforation; both patients were successfully treated by endoscopy. Conclusions ESMR-LUS appears to be a safe and effective technique for removal of small rectal NETs confined to the submucosal layer without metastasis. Further studies are warranted to compare the efficacy and safety of different methods.