Endoscopic submucosal resection using a ligation device without injection for duodenal neuroendocrine tumors

Background: Duodenal neuroendocrine tumors (NETs) measuring ≤ 10 mm in diameter that are confined to the submucosal layer without metastasis are suitable for endoscopic treatment. We previously reported the efficacy and safety of endoscopic submucosal resection with a ligation device (ESMR-L) for duodenal NETs. In order to make the procedure simpler, we attempted ESMR-L without submucosal injection. The aim of this study was to evaluate the efficacy of ESMR-L without injection for duodenal NETs. Methods: A total of 12 patients with small (≤ 10 mm) sporadic duodenal NETs were treated via endoscopic resection at the National Cancer Center Hospital East between December 2010 and May 2018. All patients were evaluated via endoscopy and endoscopic ultrasound, and abdominal computed tomography was performed to rule out metastatic lesions. The patients’ characteristics, clinical courses, and complications, such as perforation and bleeding, were retrospectively assessed. We examined the correlation between ESMR-L with or without submucosal saline injection and clinicopathological parameters. Results: The median procedural time for ESMR-L was 13 min. All lesions invaded the submucosal layer, and the histological diagnoses were classified as NET G1 in 11 lesions and NET G2 in one lesion. En bloc resection and complete resection were achieved in 12 and 11 lesions, respectively. The postoperative duration of hospital stay was 4 days. At the median follow-up of 17 months, there was no incidence of local recurrence or distant metastasis. Perforation and intraoperative bleeding were not observed. However, delayed bleeding was found in one patient. ESMR-L without submucosal injection required a significantly shorter procedural time than ESMR-L with submucosal saline injection (10 min vs. 15 min, respectively; p = 0.007). Conclusions: ESMR-L is safe and effective. Particularly, ESMR-L without submucosal injection could be used to treat these NETs safely within a short period of time.