Operative Approach Does Not Impact Radial Margin Positivity in Distal Rectal Cancer

Background: Robotic surgery is attractive for resection of low rectal cancer due to greater dexterity and visualization, but its benefit is poorly understood. We aimed to determine if operative approach impacts radial margin positivity (RMP) and postoperative outcomes among patients undergoing abdominoperineal resection (APR). Methods: This was a retrospective cohort study of patients from the National Surgical Quality Improvement Program who underwent APR for low rectal cancer from 2016 to 2019. Patients were stratified by operative approach: robotic, laparoscopic, and open APR (R-APR, L-APR, and O-APR). Emergent cases were excluded. The primary outcome was RMP. 30-day postoperative outcomes were also evaluated, using logistic regression analysis. Results: Among 1,807 patients, 452 (25.0%) underwent R-APR, 474 (26.2%) L-APR, and 881 (48.8%) O-APR. No differences regarding RMP (13.5% R-APR vs. 10.8% L-APR vs. 12.3% O-APR, p = 0.44), distal margin positivity, positive nodes, readmission, or operative time were observed between operative approaches. Adjusted analysis confirmed that operative approach did not predict RMP (p > 0.05 for all). Risk factors for RMP included American Society of Anesthesiologists (ASA) classification III (ASA I-II ref; OR 1.46, p = 0.039), pT3-4 stage (T0-2 ref, OR 4.02, p < 0.001), pN2 stage (OR 1.98, p = 0.004), disseminated cancer (OR 1.90, p = 0.002), and lack of preoperative radiation (OR 1.98, p < 0.01). Conclusions: No difference in RMP was observed among R-APR, L-APR, and O-APR. Postoperatively, R-APR yielded greater benefit when compared to O-APR, but was comparable to that of L-APR. Minimally invasive surgery may be an appropriate option and worthy consideration for patients with distal rectal cancer requiring APR.