Propensity matched analysis of robotic and laparoscopic operations for mid-low rectal cancer: short-term comparison of anal function and oncological outcomes

Laparoscopic surgery for rectal cancer, while in some respects equivalent or even preferable to open surgery, is challenged in specific conditions where the tumor is located in the middle and lower third of the rectum. Robotic surgery equipped with a superior arm of machinery and gained better visualization can compensate for the deficiency of the laparoscopic approach. This study adopted a propensity matched analysis to compare the functional and oncological short-term outcomes of laparoscopic and robotic surgery. All patients who underwent proctectomy have been collected prospectively between December 2019 and November 2022. After censoring for inclusion criteria, we performed a propensity matching analysis. A detailed collection of post-operative examination indicators was performed, while the K-M survival curves were plotted to analyze post-operative oncology outcomes. The LARS scale was designed to evaluate the anal function of patients in the form of questionnaires. Totally, 215 patients underwent robotic operations while 1011 patients selected laparoscopic operations. Patients matched 1∶1 by propensity score were divided into the robotic and laparoscopic groups, 210 cases were included in each group. All patients underwent a follow-up for a median period of 18.3 months. Robotic surgery was connected with an enhanced recovery including the earlier time to first flatus passage without ileostomy (P = 0.050), the earlier time to liquid diet without ileostomy (P = 0.040), lower incidence of urinary retention (P = 0.043), better anal function 1 month after LAR without ileostomy (P < 0.001), longer operative time (\P = 0.042), compared with laparoscopic operations. The oncological outcomes and occurrence of other complications were comparable between the two approaches. For mid-low rectal cancer, robotic surgery could be recognized as an effective technique with identical short-term outcomes of oncology and better anal function in comparison to laparoscopic surgery. However, multi-center studies with larger samples are expected to validate the long-term outcomes of robotic surgery.