AIM To assess the safety and feasibility of laparoscopic and endoscopic co-operative surgery(LECS) for early nonampullary duodenal tumors.METHODS Twelve patients with a non-ampullary duodenal tumor underwent LECS at our hospital. One patient had two mucosal lesions in the duodenum. The indication for this procedure was the presence of duodenal tumors with a low risk for lymph node metastasis. In particular, the tumors included small(less than 10 mm) submucosal tumors(SMT) and epithelial mucosal tumors, such as mucosal cancers or large mucosal adenomas with malignant suspicion. The LECS procedures, such as full-thickness dissection for SMT and laparoscopic reinforcement after endoscopic submucosal dissection(ESD) for epithelial tumors, were performed for the 13 early duodenal lesions in 12 patients. Here we present the short-term outcomes and evaluate the safety and feasibility of this new technique.RESULTS Two SMT-like lesions and eleven superficial epithelial tumor-like lesions were observed. Seven and Six lesions were located in the second and third parts of the duodenum, respectively. All lesions were successfully resected en bloc. The defect in the duodenal wall was manually sutured after resection of the duodenal SMT. For epithelial duodenal tumors, the ulcer bed was laparoscopically reinforced via manual suturing after ESD. Intraoperative perforation occurred in two out of eleven epithelial tumor-like lesions during ESD; however, they were successfully laparoscopically repaired. The median operative time and intraoperative estimated blood loss were 322 min and 0 mL, respectively. Histological examination of the tumors revealed one adenoma with moderate atypia, ten adenocarcinomas, and two neuroendocrine tumors. No severe postoperative complications(Clavien-Dindo classification grade Ⅲ or higher) were reported in this series, but minor leakage secondary to pancreatic fistula occurred in one patient.CONCLUSION LECS can be a safe and minimally invasive treatment option for non-ampullary early duodenal tumors. AIM To assess the safety and feasibility of laparoscopic and endoscopic co-operative surgery (LECS) for early nonampullary duodenal tumors. METHODS Twelve patients with a non-ampullary duodenal tumor underwent LECS in our hospital. One patient had two mucosal lesions in the duodenum. The indication for this procedure was the presence of duodenal tumors with a low risk for lymph node metastasis. In particular, the tumors included small (less than 10 mm) submucosal tumors (SMT) and epithelial mucosal tumors, such as mucosal cancers or large mucosal The LECS procedures, such as full-thickness dissection for SMT and laparoscopic reinforcement after endoscopic submucosal dissection (ESD) for epithelial tumors, were performed for the 13 early duodenal lesions in 12 patients. Here we present the short-term outcomes and evaluate the safety and feasibility of this new technique .RESULTS Two SMT-like lesions and eleven superficial epithelial tumors-like lesions were o Seven lesions were located in the second and third parts of the duodenum, respectively. All lesions were successfully resected en bloc. The defect in the duodenal wall was manually sutured after resection of the duodenal SMT. For epithelial duodenal tumors, the ulcer bed was laparoscopically reinforced via manual suturing after ESD. Intraoperative perforation occurred in two out of eleven epithelial tumor-like lesions during ESD; however, they were successfully laparoscopically repaired. The median operative time and intraoperative estimated blood loss were 322 min and 0 mL , respectively. Histological examination of the tumors revealed one adenoma with moderate atypia, ten adenocarcinomas, and two neuroendocrine tumors. No severe postoperative complications (Clavien-Dindo classification grade III or higher) were reported in this series, but minor leakage secondary to pancreatic fistula occurred in one patient .CONCLUSION LECS can be a safe and minimally invasive treatmen toption for non-ampullary early duodenal tumors.