Robotic versus laparoscopic surgery for mid and low rectal cancer: a propensity score–matched analysis of short-term outcomes and costs

PURPOSE: Robotic and laparoscopic approaches to rectal cancer surgery yield comparable short-term outcomes; however, comparative inpatient costs, particularly when stratified by tumor level, remain insufficiently characterized. This study compared short-term clinical and pathological outcomes, as well as index hospitalization costs, for minimally invasive surgery in patients with mid and low rectal cancer. METHODS: All consecutive patients with mid (5-10 cm from the anal verge) and low (<5 cm from the anal verge) rectal cancer who underwent elective minimally invasive surgery between January 2018 and December 2023 were identified. One-to-one propensity score matching was performed using the following covariates: age, sex, body mass index, American Society of Anesthesiologists physical status, tumor level, receipt of neoadjuvant therapy, and presence of a defunctioning stoma. Outcomes and cost components were compared overall and stratified by tumor level. RESULTS: After matching, 282 patients were included (laparoscopic surgery, n=141; robotic surgery, n=141). Median operative time was longer in the robotic group (368 minutes vs. 325 minutes, P=0.007), whereas the median postoperative length of stay was similar between groups (6.0 days vs. 6.0 days, P=0.255). Rates of conversion to open surgery, anastomotic leak, 30-day mortality, and 30-day readmission did not differ significantly. Histopathological indicators of resection quality, including lymph node yield, margin clearance, and completeness of total mesorectal excision, were comparable. Mean index hospitalization cost was higher in the robotic group (SGD 37,436 vs. SGD 31,724; difference, SGD 5,713; P=0.008), with a greater difference observed in mid rectal cancer (SGD 8,606; P=0.008) than in low rectal cancer (SGD 1,811; P=0.465). CONCLUSION: Robotic and laparoscopic surgery yielded comparable short-term clinical and pathological outcomes. Although costs were higher with robotic surgery, the cost differential was smaller for low rectal cancer, identifying this subgroup as a priority for prospective evaluation of clinical and economic value.