[Comparison of short-term outcomes of robotic and laparoscopic surgery for mid-low rectal cancer: a propensity...

Objective: To investigate the short-term efficacy of robotic and laparoscopic surgery for treatment of mid-low rectal cancer. Methods: This was a retrospective cohort study of clinical data of patients with mid-low rectal cancer (caudad edge of tumor less than 10 cm from the anal verge) treated with laparoscopic or robotic radical surgery in the Northern Jiangsu People's Hospital Affiliated to Nanjing University from July 2019 to November 2021. Patients whose anus had not been completely preserved, with malignant obstruction or perforation, with poor anal function indicated by preoperative low anterior resection syndrome (LARS) scores, or with incomplete follow-up information were excluded. The inclusion criteria were met by 973 patients. After matching participants in a 1:2 propensity ratio with a caliper width of 0.02 standard deviations to reduce bias between patients caused by baseline imbalances, 175 patients were included in the robotic surgery group(RS) and 350 patients in the laparoscopic surgery group(LS). Baseline characteristics did not differ significantly between these two groups. The primary objectives were to compare oncological prognoses between the two groups, including disease-free survival (DFS), overall survival (OS), and anal function as assessed by the low anterior resection syndrome (LARS) scoring system, 6 months and 12 months postoperatively. Secondary outcomes included postoperative quality of life using the quality-of-life questionnaire C30 (QLQ-C30) and the QLQ-CR38 to establish a new scale, these being evaluated 6 and 12 months postoperatively. Higher functional module scores indicate better patient function, whereas lower symptom module scores indicate milder symptoms. Additionally, we compared the incidence of perioperative-related complications in the study patients. Results: (1) Oncological outcomes: The 2-year DFS and OS rates were 89.7% and 93.1%, respectively, for the robotic group and 86.0% and 91.7%, respectively, for the laparoscopic group. These differences are not statistically significant (P=0.230 for DFS, P=0.570 for OS). (2) Anal function: Among patients who had not undergone ileostomy, anal function was better in the robotic than in the laparoscopic group 6 months postoperatively (severe LARS: 9.8% [14/143] vs. 19.2% [56/292], χ² = 6.712; P = 0.035). However, 12 months postoperatively, anal function did not differ significantly between the two groups. In patients with an ileostomy, anal function did not differ significantly between the two groups at 6 or 12 months postoperatively (both P > 0.05). (3) Postoperative quality-of-life: Compared with the laparoscopic group, the robotic group had better scores in the following aspects of quality of life: physical functioning (mean score 77.1±6.9 vs. 71.7±5.6, t =8.965, P=0.005), role in functioning (mean score 73.4±5.3 vs. 71.6±5.1, t = =3.851, P = 0.010), urinary tract complications (mean score 17.5±1.5 vs. 23.4±1.6, t = 41.40, P =0.001), and gastrointestinal symptoms (mean score 21.2±2.1 vs. 26.6±1.9, t = 29.40, P =0.001). These differences are all statistically significant (all P <0.05). By 12 months postoperatively, there were no statistically significant differences in functional or symptom modules of quality-of-life between the two groups (both P >0.05). (4) Perioperative complications: There was no statistically significant difference in intraoperative complications between the two groups (P > 0.05). The incidence of postoperative urinary retention was significantly higher in the laparoscopic than the robotic group (5.0% [19/350] vs. 1.7% [3/175], χ² = 4.009, P = 0.044). Conclusion: In our study, robotic radical surgery for rectal cancer achieved short-term oncological outcomes similar to those achieved by laparoscopic radical surgery for rectal cancer. However, robotic radical surgery had advantages in terms of anal function and postoperative quality of life, while also reducing the incidence of perioperative urinary complications.