Short-term outcomes of da Vinci SP versus Xi for rectal cancer surgery: a propensity score matching analysis of two tertiary center cohorts

Background This study compares the perioperative outcomes of robotic rectal cancer surgery between da Vinci single-port (SP) system, the most recent system allowing minimally invasive surgery with reduced ports, and the da Vinci Xi system. Methods Patients who underwent robotic surgery for rectal adenocarcinoma from January 2016 to September 2023 at two tertiary referral centers were included. A retrospective analysis was conducted to compare key parameters between patient cohorts before and after propensity score matching. Results A total of 378 patients (SP, 65 vs. Xi, 313) were analyzed. The SP group comprised a higher proportion of females (44.6% vs. 28.4%; p = 0.016) and a higher tumor location (8.25 cm vs. 6.71 cm from the anal verge; p < 0.001) than did the Xi group. SP surgery promoted a shorter total incision length (4.9 cm vs. 9.2 cm; p < 0.001), lower maximum pain scores (5 vs. 7; p < 0.001), and shorter hospital stay (6 vs. 7 days; p < 0.001) than did Xi surgery. Operation time (175 vs. 182 min; p = 0.829) and postoperative complications (9.2% vs. 12.1%; p = 0.650) did not significantly differ between the groups. Lower lying rectal tumors were more frequently treated using the Xi system than the SP system, promoting a higher diverting stoma rate (13.8% vs. 45.4%; p < 0.001) and a lower anastomosis level (4.6 cm vs. 3.3 cm; p < 0.001). After 1:1 matching, SP maintained its advantages over Xi in terms of incision length (p < 0.001), maximum pain scores (p = 0.001), and hospital stay (p < 0.001). Overall postoperative complication rates were similar between both groups (10.8% vs. 12.3%; p = 0.777). Conclusions The da Vinci SP system continues to offer minimal invasive benefits in rectal cancer surgery. However, the Xi system's instrument diversity provides a certain advantage, particularly in cases involving low-lying rectal tumors. Tailoring robotic approaches based on individual patient characteristics remains pivotal for optimizing outcomes of rectal cancer surgery.