LAUSR

183Background: The laparoscopic gastrectomy is becoming widespread. But acquisition of its technique is challenging. We investigated whether supervision by a technically qualified surgeon (QS) affects the feasibility and safety of laparoscopic gastrectomy performed by trainee (TR). Methods: The outcomes of laparoscopy-assisted distal gastrectomy for gastric cancer performed by QS group and TR group between 2013 and 2016 were assessed. A laparoscopic surgeon qualified by the Endoscopic Surgical Skill Qualification System (Japan Society for Endoscopic Surgery) participated in surgeries that ware performed by trainee as the teaching assistant. Results: All patient characteristics were not different between QS group and TR group, except of BMI (median BMI 23.9 vs 22.2, p = 0.01). Although operation time of TR group was longer than that of QS group (median time: 248 min. vs 285 min., p = 0.01), Blood loss and number of harvested lymph nodes were not different. One patient (0.3%) in QS group and two patients (0...