Robotic versus laparoscopic rectal cancer surgery during institutional transition: a 10-year sequential cohort study.

Background: The potential clinical benefits of robotic rectal cancer surgery compared with conventional laparoscopy remain a matter of debate. This study compared perioperative, pathological, and mid-term oncologic outcomes after robotic and laparoscopic rectal cancer resection in a single-center cohort. Methods: This retrospective sequential era-based cohort study included consecutive patients with UICC stage I-III rectal adenocarcinoma undergoing elective minimally invasive rectal resection between 2015 and 2024. Laparoscopy represented the institutional standard until June 2018; following implementation of the da Vinci X platform, robotic surgery became the preferred minimally invasive approach. Thus, the present analysis reflects an institutional transition between two surgical eras rather than a contemporaneous comparison of coexisting surgical techniques. The primary outcomes were conversion to open surgery and quality of mesorectal excision. Secondary outcomes included operative duration, hospital stay, anastomotic leakage, major morbidity, reoperation, 30- and 90-day mortality, and oncologic survival endpoints. To reduce baseline imbalance between treatment groups, propensity score overlap weighting was applied. Results: The study included 239 patients, of whom 146 underwent robotic resection and 93 underwent laparoscopic resection. The rate of conversion to open surgery was significantly lower in the robotic group compared with the laparoscopic group (2.7% vs 15.1%; OR 0.15, 95% CI: [0.02; 0.95], p = 0.044). Mesorectal specimen quality did not differ substantially between groups. Compared with laparoscopy, the robotic approach was associated with a shorter postoperative stay (mean difference -4.72 days, 95% CI: [-6.62; -2.82], p < 0.0001) but a longer operative time (+35.33 min, 95% CI: [17.50; 53.15], p = 0.0001). No statistically significant between-group differences were found for anastomotic leakage, major complications, reoperation, or 30- and 90-day mortality. During follow-up of up to 60 months, no statistically significant differences were observed between groups regarding overall survival, disease-free survival, local recurrence, or distant metastasis. Conclusion: Within the limitations of this sequential retrospective cohort, robotic rectal cancer surgery was associated with fewer conversions and shorter postoperative hospitalization, without an observed detriment in pathological quality or available mid-term oncologic outcomes. Although these findings suggest potential perioperative advantages of the robotic approach, the study was not powered to establish definitive oncologic equivalence.