Robot-Assisted Total Mesorectal Excision Versus Laparoscopic Total Mesorectal Excision: A Retrospective Propensity Score-Matched Cohort Analysis in Experienced Centers

BACKGROUND: The superiority of robot-assisted over laparoscopic total mesorectal excision has not been proven. Most studies do not consider the learning curve while comparing the surgical technique. OBJECTIVE: This study aims to compare laparoscopic with robot-assisted total mesorectal excision performed by surgeons who completed the learning curve of the technique. DESIGN: This is a multicenter retrospective propensity score-matched analysis. SETTINGS: The study was performed in 2 large, dedicated robot-assisted hospitals and 5 large, dedicated laparoscopic hospitals. PATIENTS: Patients were included if they underwent a robot-assisted or laparoscopic total mesorectal excision for rectal cancer with curative intent at a dedicated center for the minimally invasive technique between January 1, 2015, and December 31, 2017. INTERVENTIONS: We compared robot-assisted with laparoscopic total mesorectal excision. MAIN OUTCOME MEASURES: The main outcome was conversion to laparotomy during surgery. Secondary outcomes were postoperative morbidity and positive circumferential resection margin. RESULTS: A total of 884 patients were included and, after matching, 315 patients per treatment group remained. Conversion was similar between laparoscopic and robot-assisted total mesorectal excision (4.4% vs 2.5% (p = 0.20)). Positive circumferential resection margin was equal (3.2% vs 4.4% (p = 0.41)). Overall morbidity was comparable as well, although a lower rate of wound infections was observed in the robot-assisted group (5.7% vs 1.9% (p = 0.01)). More primary anastomoses were constructed in the robot-assisted group (50.8% vs 68.3% (p < 0.001)). Finally, more open procedures were performed in dedicated laparoscopic centers, with an overrepresentation of cT4N+ tumors in this group. LIMITATIONS: This is a retrospective multicenter cohort; however, propensity score matching was applied to control for confounding by indication. CONCLUSIONS: Robot-assisted and laparoscopic total mesorectal excision are equally safe in terms of shortterm outcomes. However, with the robot-assisted approach, more primary anastomoses were constructed, and a lower wound infection rate was observed.

Automated summary

Robot-assisted and laparoscopic total mesorectal excision have similar safety profiles in terms of short-term outcomes, but the robot-assisted approach more frequently utilizes primary anastomoses and has a lower rate of wound infections.