A comparative study of robotic and laparoscopic radical resection for locally advanced gastric cancer on the dissection of lymph nodes in the upper pancreas and the effect on the pancreas

Abstract Purpose By comparing the short-term clinical outcome of robotic gastrectomy versus laparoscopic gastrectomy in D2 radical gastrectomy for locally advanced gastric cancer, we explored whether robotic surgery has advantages in suprapancreatic lymph node dissection and examined its effect on the pancreas. Methods We collected the clinical data of 210 consecutive patients with locally advanced gastric cancer who had undergone radical gastrectomy at our center between September 2017 and June 2018. Two groups of patients were analysed: the robotic group (n = 95) and the laparoscopic group (n = 115). Operative outcomes and postoperative complications as well as pathological data were statistically analysed. Results In cases of total radical gastrectomy, the robotic group was associated with lower intraoperative blood loss compared with the laparoscopic group (108.17±92.33 VS 142.00±80.23) mL (P=0.045). Among overweight patients with BMI>25, the robotic group still showed lower intraoperative blood loss in comparison with the laparoscopic group (126.60±80.80 VS 149.11±93.23) mL (P=0.041). In cases of distal subtotal radical gastrectomy, the number of harvested No.9 lymph nodes, No.11P lymph nodes, station 2 lymph nodes and suprapancreatic lymph nodes was higher in the robotic group as compared with the laparoscopic group (p =0.043,0.034, 0.01,0.01). In cases of total radical gastrectomy, the robotic group revealed more harvested NO.8a lymph nodes, station 2 lymph nodes and suprapancreatic lymph nodes than that in the laparoscopic group（P =0.026，0.043,0.03）. Whether or not the patients were overweight, the robotic group was associated with more harvested lymph nodes（P=0.001，0.036）.The robotic group was associated with lower drainage fluid amylase levels on postoperative day 1 and lower blood amylase on postoperative day 2 and day 3 when compared with the laparoscopic group （P=0.043，0.014，0.001）. The robotic group reported 5 cases（5.3%）of biochemical leak compared with 16 cases（13.9%） in the laparoscopic group（P=0.038). Among patients with BMI＜25(kg/m2), the robotic group showed lower levels of blood amylase on postoperative day 3. Among patients with BMI≥25(kg/m2), the robotic group showed lower ascitic fluid amylase level on postoperative day 1, lower blood amylase level on postoperative day 2 and less intraabdominal drainage liquid（P=0.043，0.008，0.043）on postoperative day 1.Conclusion In cases of D2 radical gastrectomy for locally advanced gastric cancer, the robotic group was associated with less blood loss and more harvested perigastric lymph nodes in the suprapancreatic area as well as less pancreatic injury compared with the laparoscopic group. Among overweight patients, the robotic group showed advantages as well.