P-042The clinical outcomes and feasibility of endoscopic full-thickness resection assisted laparoscopic surgery for duodenal neuroendocrine tumor

Introduction: Duodenal neuroendocrine tumors (dNETs) are arising from the cells of the mucosal layer and often small and confined to the superficial layer. Surgery and endoscopic resection are both considered appropriate; however, there are critical hurdles to both modalities in real practice. Laparoscopic surgery has difficulty in terms of determining precise tumor location and endoscopic resection has high risks for bleeding, perforation, and incompleteness. In our study, we compared the treatment outcomes of endoscopic full-thickness resection assisted laparoscopic surgery (EFTRLS). Methods: The electronic medical record database was reviewed at a university hospital (Yeouido St. Mary’s Hospital) in Seoul, Korea. A total of 33 patients were found to be diagnosed during the last 10 years, from June 2008 to December 2018. Results: Among the 33 patients with dNETs, 12 were excluded, due to follow-up loss (3), transfer-out (2), treatment refusal (2), invisibility after forceps biopsy (2), poorly differentiated histology (2), and the presence of a metastatic lesion (1). Twenty-one patients who showed well-differentiated histology, with less than 2 mitoses per 10 HPF and less than 3 Ki-67 index, underwent excision of tumors. Sixteen were treated with endoscopic resection, and 3 with surgery. Four were with EFTRLS. Resection margin involvement was none in the EFTRLS group compare to other single modality groups (0% [0/4 cases] vs 19% [3/16 endoscopic resection] vs 33% [1/3 surgery only]). One endoscopically-treated patient had a macroscopic residual tumor and needed additional surgery. Two patients of endoscopic resection group experienced perforation and underwent surgery. Tumor recurrence and metastasis were not reported during the study period in all patients. Conclusion: EFTRLS provides a precise and secure safety margin of tumor resection and abolishes the risk of uncontrolled bleeding and perforation. EFTRLS has the advantage in oncological completeness and patient safety over either endoscopic resection alone or surgery alone.