[Comparison of short-term efficacy between robotic and 3D laparoscopic-assisted D2 radical distal gastrectomy for gastric cancer].

Objective: To compare short-term efficacy of robotic versus 3D laparoscopic-assisted D2 radical distal gastrectomy in gastric cancerpatients and those with different body mass index (BMI). Method: A retrospective cohort study was performed. Inclusion criteria:(1) gastric cancer proved by preoperative pathological results and tumor location was suitable for D2 radical distal gastrectomy; (2) no distal metastases such as in liver, kidney or abdominal cavity, and no direct invasion to the pancreas or colon on preoperative imaging; (3) postoperative pTNM stage ranged from I to III; (4) no conversion to open surgery or change of surgical procedure during operation; (5) complete clinicopathological data. Patients with severe chronic diseases, other malignant tumors, tumor invasion of other organs or distant metastases, benign gastric tumors, gastrointestinal stromal tumors and recurrent gastric cancer were excluded. According to the above criteria, 531 patients who underwent robotic or 3D laparoscopic-assisted distal gastrectomy at the General Surgery Department of Chinese PLA General Hospital from January 2016 to December 2019 were enrolled. Among them, 344 patients underwent 3D laparoscopic-assisted distal gastrectomy (3D-LADG group), including 250 males, 94 females, 66 cases (19.2%) with a BMI ≥ 25 kg/m(2), and 278 cases (80.8%) with a BMI < 25 kg/m(2), and 187 patients underwent robotic-assisted distal gastrectomy (RADG group), including 122 males, 65 females, 69 cases (36.9%) with a BMI≥25 kg/m(2) and 118 cases (63.1%) with a BMI < 25kg/m(2). There were no significant differences in baseline characteristics between the two groups (all P > 0.05). Operative indicators, postoperative recovery, pathological characteristics and complication rate were compared between the two groups. Subgroup analysis stratified BMI was also performed. Results: Compared with RADG group, 3D-LADG group presented more harvested lymph nodes (29.1±12.4 vs. 25.2±9.0, t=4.238, P<0.001), shorter postoperative hospital stay [8.0 (7.0 to 10.0) days vs. 10.0 (9.0 to 11.0) days, Z=-6.205, P<0.001], less operative cost [(3.6×10(4)±1.1×10(4)) yuan vs. (6.2×10(4)±3.5×10(4)) yuan, t=-9.727, P<0.001], less cost of hospitalization [8.6×10(4)(7.5×10(4) to 10.0×10(4)) yuan vs. 12.8×10(4)(11.7×10(4) to 14.1×10(4)) yuan, Z=-15.997, P<0.001] and longer first flatus time [(3.9±1.0) days vs. (3.4±1.2) days, t=4.271, P<0.001], whose differences were all statistically significant (all P<0.05). While there were no statistically significant differences in operation time, intraoperative blood loss, overall complication rate [10.8%(37/344) vs. 12.8%(24/187), χ(2)=0.515, P=0.473] and severe complications rate [2.0%(7/344) vs. 3.2%(6/187), χ(2)=0.294, P=0.588] between 3D-LADG group and RADG group (all P>0.05). In BMI<25 kg/m(2) group, propensity score matching (PSM) was used to reduce bias of baseline characteristics. After PSM, 3D-LADG group presented higher proportion of intraoperative blood loss <50 ml [26.7% (31/116) vs. 8.6% (10/116), χ(2)=13.065, P<0.001], more harvested lymph nodes [30.3±12.2 vs. 25.3±9.5, t=-3.192, P=0.002] and shorter postoperative hospital stay [9.0 (7.0 to 10.0) days vs. 10.0 (9.0 to 11.0) days, Z=-4.275, P<0.001] compared with RADG group, while other perioperative indicators showed no statistically significant differences between the two groups (all P>0.05). In BMI≥25 kg/m(2) group, 3D-LADG group presented higher proportion of intraoperative blood loss >200 ml [18.2% (12/66) vs. 1.4% (1/69), χ(2)=10.853, P=0.001] and shorter postoperative hospital stay [8.0 (6.0 to 10.0) days vs. 9.0 (8.0 to 10.5) days, Z=-3.039, P=0.002] compared with RADG group, while other perioperative indicators also showed no statistically significant differences between the two groups (all P>0.05). Conclusion: It is safe and feasible to perform 3D-LADG and RADG for patients with gastric cancer. The short-term efficacy of both is similar.