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.