Minimally invasive has surgery become the target of the surgeons,Da Vinci robot assisted surgical system has been used generally for colorectal cancer,with the advantages of three-dimensional high-definition imaging,flexible and high degree of freedom robotic arms,functions of action correction and shake filtration compared with laparoscopic surgery.However,advantages and disadvantages between Da Vinci robot assisted surgical system and traditional laparoscopic surgery are still controversial.In this paper,the present situation and prospect of Da Vinci robot assisted surgical system for colorectal cancer surgery are explored.

Objective:To investigate the influencing factors for the number of lymph node harvested after Da Vinci robotic and laparoscopic radical gastrectomy for gastric cancer.Methods:The retrospective case-control study was conducted. The clinicopathological data of 1 396 patients who underwent Da Vinci robotic or laparoscopic radical gastrectomy for gastric cancer in the First Affiliated Hospital of Nanchang University from December 2014 to July 2019 were collected. There were 991 males and 405 females, aged (60±11) years. Surgery using Da Vinci robotic system or laparoscopic system was completed according to patients' wishes. Cases with early gastric cancer underwent D 1+ lymphadenectomy and cases with advanced gastric cancer underwent standard D 2 lymphadenectomy. Observation indicators: (1) intraoperative situations; (2) postoperative situations; (3) influencing factors for the number of lymph node harvested after radical gastrectomy for gastric cancer; (4) follow-up and survival. Follow-up using outpatient examination or telephone interview was performed to detect survival of patients up to October 2020. Measurement data with normal distribution were represented as Mean± SD. Univariate analysis was done using the chi-square test or Fisher exact probability. Multivariate analysis was performed using Logistic regression model. The survival rate was calculated by Kaplan-Meier method. Results:(1) Intraoperative situations: all the 1 396 patients underwent radical gastrectomy, including 415 cases undergoing Da Vinci robotic radical gastrectomy and 981 cases undergoing laparoscopic radical gastrectomy. Thirty-five of the 1 396 patients were converted to open surgery, including 5 cases undergoing Da Vinci robotic radical gastrectomy and 30 cases undergoing laparoscopic radical gastrectomy. Of the 1 396 patients, 983 cases underwent distal gastrectomy, 400 cases underwent total gastrectomy and 13 cases underwent proximal gastrectomy, among which 597 cases underwent Billroth Ⅰ anastomosis, 385 cases underwent Billroth Ⅱ anastomosis, 401 cases underwent Roux-en-Y anastomosis and 13 cases underwent residual stomach-esophagus anastomosis. The operation time, volume of intraoperative blood loss and cases with intraoperative blood transfusion were (221±51)minutes, (201±81)mL, 24 of 415 cases undergoing Da Vinci robotic radical gastrectomy, and (196±42)minutes, (232±76)mL, 75 of 981 cases undergoing laparoscopic radical gastrectomy, respectively. (2) Postoperative situations: the time to postoperative first flatus, time to postoperative initial liquid food intake and duration of postoperative hospital stay of the 1 396 patients were (3.0±1.0) days, (4.2±1.5) days and (9.0±3.8) days, respectively. Two hundred and ten of the 1 396 patients had postoperative complications including 170 cases with grade Ⅰ-Ⅱ complications and 40 cases with grade Ⅲ-Ⅴ complications. Eight of the 210 patients with postoperative complications died of serious complica-tions and the other 202 cases were cured after symptomatic treatment. Results of postoperative histopathological examination showed that there were 958 cases of adenocarcinoma, 220 cases of mucinous adenocarcinoma, and 218 cases of signet ring cell carcinoma. The number of lymph node harvested and the number of positive lymph node of the 1 396 patients were 26.0±8.3 and 3.6±0.9, respectively, and cases with the number of lymph node harvested ≥16 or <16 were 1 312 and 84. (3) Influencing factors for the number of lymph node harvested after radical gastrectomy for gastric cancer: results of univariate analysis showed that the operating surgeon, operation method, range of gastric resection, nerve invasion, degree of tumor invasion and tumor pathological N stage were related factors influencing the number of lymph node harvested after Da Vinci robotic and laparoscopic radical gastrectomy for gastric cancer ( χ2=13.167, 6.029, 15.686, 5.573, 9.402, 17.139, P<0.05). Results of multivariate analysis showed that the operating surgeon, operation method, range of gastric resection and tumor pathological N stage were independent factors influencing the number of lymph node harvested after Da Vinci robotic and laparoscopic radical gastrectomy for gastric cancer ( odds ratio=1.589, 2.018, 1.787, 0.267, 95% confidence interval as 1.221?2.068, 1.140?3.570, 1.066?2.994, 0.103?0.689, P<0.05). (4) Follow-up and survival: of the 1 396 patients, 1 256 cases were followed up for 2 to 70 months, with a median follow-up time of 27 months. The 3-year cumulative survival rate of the 1 256 cases was 70.2%. Conclusion:The operating surgeon, operation method, range of gastric resection and tumor pathological N stage are independent factors influencing the number of lymph node harvested after Da Vinci robotic and laparoscopic radical gastrectomy for gastric cancer.

Objective: To compare the short-term and long-term outcomes of robotic rectectomy and laparoscopic rectectomy for rectal cancer based on propensity score matching. Methods: The clinical data of 106 patients who underwent robotic or laparoscopic radical resection of rectal cancer at Department of General Surgery, the First Affiliated Hospital of Nanchang University from January 2015 to December 2015 were retrospectively collected. Propensity score matching method was used to perform 1∶1 matching between robot and laparoscopic rectal cancer radical surgery. Thirty-two patients in robot group and 32 patients in laparoscopic group were successfully matched. There were 15 males and 17 females in the robotic group, aging (56.2±7.5) years, 19 males and 13 females in the laparoscopic group, aged (55.5±7.6) years. The clinical outcome of the two groups were compared using t-test or Mann-Whitney U test for continuous variables, repeated measures analysis of variance, χ² test, Fisher exact test or Wilcoxon rank sum test for dichotomous variables. The overall survival curve was drawn by Kaplan-Meier curve and the difference of survival curve was compared by Log-rank method. Results: The general data of the two groups of patients were comparable after matching. Sixty-four patients successfully completed robotic or laparoscopic operation without conversion to open surgery or perioperative death case. The total operative time, the lymph node namely No. 253 group dissection time, intraoperative blood loss, postoperative urethral catheter retention time, the serum C-reactive protein levels of 24 hours after surgery were (135.7±12.1) minutes, (11.6±2.7) minutes, (66.8±10.2) ml, 3.0(1.0) d,(50.9±7.7) μg/L, respectively, while in laparoscopic group were (124.9±23.2) minutes, (13.2±2.7) minutes, (74.8±13.9) ml, 4.0(2.0) d, (55.9±6.7) μg/L respectively. The differences were statistically significant (t=2.341, t=-2.354, t=-2.621, Z=-2.743, F=7.902, respectively, P<0.05). There were no statistical differences in separation time, numbers of retrieved lymph nodes, time to first flatus, postoperative hospital stay, postoperative complication and Clavien-Dindo classification of postoperative complications (t=0.336, t=0.714, t=-0.568, Z=-1.766, Fisher Z=-0.586, respectively, all P>0.05). Conclusions Robotic surgery not only has similar safety and feasibility but also has advantages of short-term outcomes compared with laparoscopic rectectomy for rectal cancer. The long-term outcomes were similar between two groups.

Objective To investigate the clinical efficacy of Da Vinci robotic and laparoscopic distal gastrectomy for gastric cancer.Methods The propensity score matching and retrospective cohort study was conducted.The clinicopathological data of 171 patients with gastric cancer who were admitted to the First Affiliated Hospital of Nanchang University from January 2015 to October 2016 were collected.There were 110 males and 61 females,aged from 38 to 81 years,with a median age of 57 years.Of 171 patients,70 undergoing Da Vinci robotic distal gastrectomy for gastric cancer and 101 undergoing laparoscopic distal gastrectomy were allocated into the robotic group and laparoscopic group,respectively.Observation indicators:(1) the propensity score matching conditions and comparison of general data between the two groups after the propensity score matching;(2) intraoperative and postoperative situations;(3) situations of pathological examination;(4) follow-up.Patients were followed up by outpatient examination and telephone interview to detect severe complications and survival after discharge up to October 2018.The overall survival time was from the operation data to end of follow-up or time of death.The propensity score matching was used to perform 1 ∶ 1 matching by Empower Stats.Measurement data with normal distribution were represented as Mean ± SD,and comparison between groups was done using the t test.Measurement data with skewed distribution were represented as M (range),and comparison between groups was done using the Mann-Whitney U test.Count data were represented as absolute number,and comparison between groups was analyzed using the chi-square test and comparison of ordinal data between groups was analyzed using the Mann-Whitney U test.The survival rate and curve were respectively calculated and drawn by the Kaplan-Meier method,and Log-rank test was used for survival analysis.Results (1) The propensity score matching conditions and comparison of general data between the two groups after the propensity score matching:124 of 171 patients had successful matching,including 62 in each group.The body mass index (BMI) and tumor diameter before matching were (24.2±2.4)kg/m2 and (50±13)mm in the robotic group,(25.1±2.1) kg/m2 and (45±14) mm in the laparoscopic group,showing statistically significant differences between the two groups (t =-2.676,2.045,P＜ 0.05).The BMI and tumor diameter after matching were (24.5 ± 2.3) kg/m2 and (49 ± 14) mm in the robotic group,(24.4 ± 2.2) kg/m2 and (48 ± 12) mm in the laparoscopic group,showing no statistically significant difference between the two groups (t=0.110,0.524,P＞0.05).(2) Intraoperative and postoperative situations:the total operation time,volume of intraoperative blood loss,level of C-reactive protein at day 1 postoperatively,level of C-reactive protein at day 3 postoperatively,volume of totally abdominal drainage were (147±13) minutes,(115±12)mL,(52.2±7.2)mg/L,(33.7±11.9)mg/L,353.5 mL (range,267.0-1 350.0 mL) in the robotic group,and (140± 12) minutes,(131 ± 12) mL,(58.2±7.4) mg/L,(41.1 ± 16.9) rag/L,397.0 mL (range,255.0-1 600.0 mL) in the laparoscopic group,respectively,showing statistically significant differences in the above indexes between the two groups (t =3.163,-7.814,-4.631,-2.840,Z =-4.351,P＜0.05).(3) Situations of pathological examination:patients after matching in the two groups received R0 resection,with negative duodenal margin and gastric margin.The number of lymph nodes dissected in the robotic group and laparoscopic group were 22±4 and 20±4,respectively,with a statistically significant difference between the two groups (t=2.812,P＜0.05).(4) Follow-up:124 patients after propensity score matching were followed up for 6-37 months,with a median time of 25 months.During the follow-up,no severe surgery-related complications such as obstruction of input or output loop and dumping syndrome were found in the two groups within 3 months after operation.The 2-year overall survival rate was 82.1％ and 75.2％ in the robotic and laparoscopic group,with no statistically significant difference between the two groups (x2 =0.436,P＞0.05).Conclusions Compared with laparoscopic surgery,Da Vinci robotic distal gastrectomy for gastric cancer has advantages in postoperative recovery and minimally invasion.There are similar 2-year overall survival rates in the two groups.

Objective:To compare the short- and long-term outcomes of robot-assisted and laparoscopic radical resection for mid-low rectal cancer.Methods:A prospective randomized controlled trial was conducted. A total of 130 patients with mid-low rectal cancer (inclusion criteria: age > 18 or ≤80 years old; pathological diagnosis of rectal adenocarcinoma by colonoscopy; distance from tumor to the anal verge ≤12 cm; no distant metastasis; cT1-3N0-1 or ycT1-3 after neoadjuvant radiotherapy and chemotherapy; suitable for laparoscopic and robotic surgery) at the Department of Colorectal Surgery of the First Affiliated Hospital of Nanchang University from October 2016 to September 2018 were prospectively enrolled. According to computer-generated random number method, patients were randomly divided into the robot group ( n=66) and laparoscopy group ( n=64), and underwent robot-assisted surgery or laparoscopic surgery respectively. Clinicopathological data of all the patients were collected and analyzed. The demographic parameters, short- and long-term outcomes were compared between two groups. Results:One patient in robot group whose postoperative sample was diagnosed as rectal adenoma by pathology was excluded. There were no statistically significant differences in age, sex, BMI, ASA classification, distance from tumor to the anal verge, serum CEA level, CA199 level between two groups (all P>0.05). Operations were successfully performed in all the patients without conversion to open operation. Robotic surgery was found to be associated with less intraoperative blood loss than laparoscopic surgery [(73.4±49.7) ml vs. (119.1±65.7) ml, t=-4.461, P<0.001], while there were no statistically significant differences in surgical procedures, operation time, time to first flatus, time to first liquid intake, time to removal of catheter or postoperative hospital stay between two groups (all P>0.05). Besides, there was no significant difference in the morbidity of postoperative complication between two groups [10.8% (7/65) vs. 12.5 (8/64), χ 2=4.342, P=0.720]. The median number of harvested lymph node in the robot group and the laparoscopy group was 15.7±6.2 and 13.8±6.1 ( t=1.724, P=0.087). There were no significant differences between two groups in tumor sample length, distance between proximal and distal resection margin, integrity grade of TME specimen, number of positive lymph nodes, postoperative pathological stage and tumor differentiation (all P>0.05). The distal resection margin of samples in two groups was all negative. One case in the robot group was found to have positive circumferential resection margin. The median follow up was 24 (9 to 31) months. In the robot group and the laparoscopy group, the 2-year overall survival rate was 95.4% and 90.6% respectively; the 2-year disease-free survival rate was 90.8% and 85.9% respectively, whose differences were not significant (both P>0.05). Conclusion:Robot-assisted radical resection for mid-low rectal cancer can achieve similar short-term and long-term outcomes of laparoscopic resection, while robot-assisted surgery can decrease blood loss during operation, leading to more precise practice in minimally invasive surgery.

Objective:To compare the short- and long-term outcomes of robot-assisted and laparoscopic radical resection for mid-low rectal cancer.Methods:A prospective randomized controlled trial was conducted. A total of 130 patients with mid-low rectal cancer (inclusion criteria: age > 18 or ≤80 years old; pathological diagnosis of rectal adenocarcinoma by colonoscopy; distance from tumor to the anal verge ≤12 cm; no distant metastasis; cT1-3N0-1 or ycT1-3 after neoadjuvant radiotherapy and chemotherapy; suitable for laparoscopic and robotic surgery) at the Department of Colorectal Surgery of the First Affiliated Hospital of Nanchang University from October 2016 to September 2018 were prospectively enrolled. According to computer-generated random number method, patients were randomly divided into the robot group ( n=66) and laparoscopy group ( n=64), and underwent robot-assisted surgery or laparoscopic surgery respectively. Clinicopathological data of all the patients were collected and analyzed. The demographic parameters, short- and long-term outcomes were compared between two groups. Results:One patient in robot group whose postoperative sample was diagnosed as rectal adenoma by pathology was excluded. There were no statistically significant differences in age, sex, BMI, ASA classification, distance from tumor to the anal verge, serum CEA level, CA199 level between two groups (all P>0.05). Operations were successfully performed in all the patients without conversion to open operation. Robotic surgery was found to be associated with less intraoperative blood loss than laparoscopic surgery [(73.4±49.7) ml vs. (119.1±65.7) ml, t=-4.461, P<0.001], while there were no statistically significant differences in surgical procedures, operation time, time to first flatus, time to first liquid intake, time to removal of catheter or postoperative hospital stay between two groups (all P>0.05). Besides, there was no significant difference in the morbidity of postoperative complication between two groups [10.8% (7/65) vs. 12.5 (8/64), χ 2=4.342, P=0.720]. The median number of harvested lymph node in the robot group and the laparoscopy group was 15.7±6.2 and 13.8±6.1 ( t=1.724, P=0.087). There were no significant differences between two groups in tumor sample length, distance between proximal and distal resection margin, integrity grade of TME specimen, number of positive lymph nodes, postoperative pathological stage and tumor differentiation (all P>0.05). The distal resection margin of samples in two groups was all negative. One case in the robot group was found to have positive circumferential resection margin. The median follow up was 24 (9 to 31) months. In the robot group and the laparoscopy group, the 2-year overall survival rate was 95.4% and 90.6% respectively; the 2-year disease-free survival rate was 90.8% and 85.9% respectively, whose differences were not significant (both P>0.05). Conclusion:Robot-assisted radical resection for mid-low rectal cancer can achieve similar short-term and long-term outcomes of laparoscopic resection, while robot-assisted surgery can decrease blood loss during operation, leading to more precise practice in minimally invasive surgery.