Robotic Versus Laparoscopic Rectal Cancer Surgery in Obese Patients: A Frequentist and Bayesian Meta-Analysis

Background: Obesity poses significant technical challenges during rectal cancer surgery (RCS). Robotic surgery may improve operative performance in this setting. We therefore performed a systematic review and meta-analysis comparing robotic and laparoscopic approaches in obese patients. Methods: A systematic search was conducted across PubMed, Web of Science, Scopus, and the Cochrane Central Register of Controlled Trials up to May 2026. Pooled odds ratios (ORs) and mean differences (MDs) with 95% confidence intervals (CIs) were calculated using random-effects models. Bayesian analyses were additionally performed for overall morbidity and conversion to open surgery. Results: Five observational studies involving 531 patients were included, of whom 280 underwent robotic RCS, and 251 underwent laparoscopic RCS. Robotic surgery was associated with a significantly shorter hospital stay (MD = −1.8 days; 95% CI: −2.5 to −1.0; P < .01; I 2 = 67.8%) but a longer operative time (MD = 48.5 minutes; 95% CI: 1.8–95.3; P = .04; I 2 = 81.7%). No significant differences were observed regarding conversion to open surgery, overall morbidity, anastomotic leakage, blood loss, lymph node yield, circumferential resection margin positivity, quality of total mesorectal excision, urinary retention, urinary tract infection, or surgical site infection. Bayesian analyses yielded posterior probabilities of benefit of 89.0% for conversion to open surgery and 95.0% for overall morbidity. Conclusion: Robotic RCS in obese patients was associated with shorter hospitalization but longer operative time compared with laparoscopy. Perioperative morbidity and pathological outcomes were comparable between approaches in conventional analyses, although Bayesian analyses suggested higher posterior probabilities of benefit for conversion to open surgery and overall morbidity; however, these findings should be interpreted cautiously given the wide credible intervals and very low certainty of evidence. Further high-quality prospective studies are needed to confirm these findings.