Improved perioperative outcomes and reduced inflammatory stress response in malignant robot-assisted colorectal resections: a retrospective cohort study of 298 patients

Background Robot-assisted surgery is increasingly implemented for the resection of colorectal cancer, although the scientific evidence for adopting this technique is still limited. This study's main objective was to compare short-term complication rates, oncological outcomes, and the inflammatory stress response after colorectal resection for cancer performed laparoscopic or robot-assisted. Methods We conducted a retrospective cohort study comparing the robot-assisted approach to laparoscopic surgery for elective malignant colorectal neoplasm. Certified colorectal and da Vinci [R] robotic surgeons performed resections at a Danish tertiary colorectal high volume center from May 2017 to March 2019. We analyzed the two surgical groups using uni- and multivariate regression analyses to detect differences in intra- and postoperative clinical outcomes and the inflammatory stress response. Results Two hundred and ninety-eight patients were enrolled in the study. Significant differences favoring robot-assisted surgery was demonstrated for; length of hospital stay (4 days, interquartile range (4, 5) versus 5 days, interquartile range (4-7), p < 0.001), and intraoperative blood loss (50 mL, interquartile range (20-100) versus 100 mL, interquartile range (50-150), p < 0.001) compared to laparoscopic surgery. The inflammatory stress response was significantly higher after laparoscopic compared to robot-assisted surgery reflected by an increase in C-reactive protein concentration (exponentiated coefficient = 1.23, 95% confidence interval (1.06-1.46), p = 0.008). No differences between the two groups were found concerning mortality, microradical resection rate, conversion to open surgery, and surgical or medical short-term complication rates. Conclusion Robot-assisted surgery is feasible and can be safely implemented for colorectal resections. The robot-assisted approach, when compared to laparoscopic surgery, was associated with improved intra- and postoperative outcomes. Extensive prospective studies are needed to determine the short- and long-term outcomes of robotic surgery for colorectal cancer. Keywords: Colorectal cancer, Robot-assisted colorectal surgery, Laparoscopic colorectal surgery, Postoperative inflammatory stress response, Surgical oncology, Minimally invasive surgery