Objective  To investigate and compare the abilities of robot-assisted gastrectomy (RAG) and laparoscopy-assisted gastrectomy (LAG) to remove lymph nodes in technically demanding areas.

  Methods  Between August 2014 and August 2015, 61 patients who underwent RAG and 235 patients who underwent LAG were enrolled in this study. Clinical characteristics, operative parameters, and pathological and oncological data were collected prospectively, and the numbers of retrieved lymph nodes for each station were analyzed in accordance with the extent of surgery.

  Results  More lymph nodes were retrieved in the RAG group than in the LAG group (P=0.046). Similarly, the RAG group had more retrieved lymph nodes in the N2 area (P=0.038). In patients who underwent distal gastrectomy, the numbers of retrieved lymph nodes around the splenic artery area using RAG and LAG were 2.8±1.7 and 2.2±1.2, respectively (P= 0.036). In patients who underwent total gastrectomy, 2.8±1.2 and 2.1±1.0 lymph nodes were retrieved with RAG and LAG around the splenic artery area, respectively (P=0.049). The mean numbers of lymph nodes retrieved around the splenic hilum were 1.8±0.8 and 1.3±0.7, respectively (P=0.042). The intraoperative blood transfusion rate (P=0.617), postoperative hospital days (P=0.071), proximal resection margin (P=0.064), and distal resection margin (P=0.667) were not significantly different between the two groups. The numbers of postoperative complications were also similar between the RAG and LAG groups (P=0.854). However, RAG had less severe complications according to the Clavien-Dindo classification (P=0.039).

  Conclusions  This study demonstrated that RAG had advantages over LAG regarding lymph node dissection in technically demanding areas and might contribute to radical D2 lymphadenectomy with less severe complications.