[Efficacy comparison between robot-assisted and laparoscopic surgery for mid-low rectal cancer: a prospective randomized controlled trial]

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.

[Short-term clinical efficacy of robotic radical resection for high rectal cancer with transvaginal specimen extraction]

Objective: To explore the short-term clinical efficacy of robotic radical resection for high rectal cancer with transvaginal specimen extraction. Methods: A cohort study was carried out. The clinical data of consecutive patients with high rectal cancer who underwent robotic radical resection at the Department of General Surgery of The First Affiliated Hospital of Nanchang University from June 2017 to January 2018 were retrospectively analyzed. Inclusion criteria: (1) preoperative diagnosis of rectal cancer, and distance from tumor to anal margin≥10 cm undercolonoscopy; (2) T1-3 assessed by preoperative imaging examination, and no distant metastasis; (3) female, age≥50 years old, body mass index ≤ 30 kg/m(2); (4) without radiotherapy and chemotherapy before surgery; (5) implementation of robotic radical surgery for high rectal cancer. Fourteen female patients undergoing transvaginal removal of specimen without abdominal incision were included in the no incision group with age of (62.2±9.3) years old and distance from tumor to anal verge of (12.5±0.9) cm. As the match of 1:2, 28 simultaneous patients of high rectal cancer undergoing traditional robotic surgery (surgery interval <8 months) were enrolled to the control group, with age of (60.6±12.8) years old and distance from tumor to anal verge of (11.3±3.8) cm. Short-term efficacy and safty were compared between two groups. Follow-up ended in September 2018. Results: There was no significant difference in baseline data between the two groups (all P>0.05). Compared with the control group, the no incision group had longer operation time [(149.6±15.6) minutes vs. (130.9±12.9) minutes, t=-4.135, P<0.001], shorter time to postoperative flatus [(40.9 ±2.6) hours vs. (51.9±2.9) hours, t=12.049, P<0.001], lower pain score on the operation day and the first day after surgery (using Changhaipainstick) [(3.1±0.4) points vs. (4.6±0.7) points, t=7.458, P<0.001; (2.5±0.3) points vs. (3.3±0.5) points, t=6.142, P<0.001], shorter time to ground activity [(15.6±2.0) hours vs. (24.3±2.5) hours, t=11.102, P=0.030], and shorter postoperative hospital stay [(6.1±0.8) days vs. (7.2±1.3) days, t=2.806, P=0.008], whose differences were statistically significant. There were no significant differences in intraoperative blood loss, proportion of postoperative analgesia patients, and complication within 30 days after surgery (all P>0.05). In the no incision group and the control group,the tumor size was (3.1±0.4) cm and (3.6±0.9) cm, the proximal margin distance was (9.1±1.5) cm and (9.8±1.5) cm, the distal margin distance was (4.3±0.4) cm and (4.5±0.4) cm, the number of harvested lymph node was 15.8±2.4 and 15.2 ± 2.5, and the number of positive lymph node was 0.6±1.3 and 1.1±2.4, respectively, whose differences were not statistically significant (all P>0.05). The mean followed-up period was 10 months (7-14 months) in the no incision group, and 14 months (10-18 months) in the control group. No local recurrence and distant metastasis were found in both groups. Conclusion: Robotic radical resection for high rectal cancer with transvaginal specimen extraction is safe and feasible with advantages of rapid postoperative recovery, less postoperative pain and short hospital stay.