Su1277 THE RESULTS OF ENDOSCOPIC MUCOSAL RESECTION WITH A LIGATION DEVICE FOR DUODENAL NEUROENDOCRINE TUMORS

Abstract

The treatments for duodenal neuroendocrine tumors (NETs) have included conventional surgical resection, resection by laparoscopic-endoscopic cooperative surgery, endoscopic submucosal dissection (ESD), endoscopic mucosal resection (EMR), and endoscopic mucosal resection with ligation (EMR-L). Duodenal NETs located in the submucosal layer without lymph node or distant metastasis are good candidates for endoscopic treatment. While EMR requires far less technical skill than ESD, the vertical margin of NETs removed by EMR is often positive. Our department selects EMR-L for the resection of duodenal NETs of the submucosal layer without lymph node or distance metastasis, as the procedure requires less technical skill and employs a ligation device to reduce the rate of positive vertical margins. To examine the results of duodenal NET treatments performed at our institution. Nine consecutive patients with 9 duodenal NETs who underwent EMR-L treatments from October 2013 to September 2017 at Keio University Hospital were enrolled. All 9 of the lesions were confirmed as NETs pathologically by endoscopic biopsies. Assessment of the size and location of each duodenal NET by ultrasonic endoscopy (EUS) confirmed the localization of the tumor in the submucosal layer, and assessment by computed tomography (CT) confirmed the absence of lymph node and distant metastasis. Tumors of more than 13 mm in diameter were excluded from this study, as the maximum diameter of the ligation devices was 13 mm. The endoscopic results, pathological results, and prognosis were all examined. The baseline characteristics and outcomes of the 9 resected tumors in the 9 patients (7 males; mean age, 55.5 years) treated with EMR-L were analyzed. Of the 9 lesions, 6 were located in the duodenal bulb and 3 were located in the second portion of the duodenum. The mean size of resected tumors was 7.0 mm (3-12 mm). All 9 (100%) of the tumors were resected en bloc. One patient (11.1%) experienced intraoperative bleeding and none of the patients experienced delayed bleeding. Perforation occurred in one case (11.1%), but the condition was managed well by conservative therapy. None of the patients experienced delayed perforation. The vertical margins were negative in all 9 cases. Lymphatic vessel invasion was observed in 3 cases, all of whom underwent additional surgery with lymph node dissection (one of them also exhibited blood vessel invasion and a positive horizontal margin). No evidence of residual tumors or lymph node metastasis was observed in any of the cases. No recurrence was observed in any of the 9 patients (the mean follow-up period: 18.6 months, range 3 -49 months). EMR-L was a safe method for endoscopically resecting submucosal duodenal NETs of less than 13 mm, and the NETs resected by EMR-L were tumor-negative in the vertical margins.