Clear Surgical Margins in Robotic Versus Laparoscopic Total Mesorectal Excision: An ACS-NSQIP Analysis

Whether the robotic approach in total mesorectal excision (TME) is associated with increased clear radial and distal margins, compared to the laparoscopic approach, is yet to be determined.

We analyzed the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) participant user files for all elective rectal cancer cases performed with minimally invasive surgical techniques (robotic and laparoscopic). Natural orifice, single incisional, and transanal approaches were excluded from the analysis. We calculated relative risks (RR) through Poisson regression models after adjusting for age, body mass index, American Society of Anesthesiologists scores, pathologic T and N status, locations of tumor (low, middle, or high in rectum), neoadjuvant therapy, and surgical specialty.

Our primary outcome was the result of both radial and distal clear surgical margins upon pathologic analysis. Secondary outcomes included distance of clear distal margins and number of harvested lymph nodes.

Our cohort consisted of 1321 robotic cases and 2039 laparoscopic cases. There were no significant differences in demographics or tumor staging across groups, except a higher proportion of low rectal cancer in the robotic cohort. The robotic approach was associated with improved radial and distal clear margins in pathological analysis (adjusted RR: 1.06, 95% CI: [1.03-1.10], P < .001). There was a nonsignificant trend toward longer clear distal margin in the robotic cohort. No difference was observed in lymph node harvesting.

As a retrospective and nonrandomized study, residual bias and confounding variables are likely to exist. Relevant information such as mesorectal fascia involvement in clinical preoperative staging could also limit the findings.

Robotic TME is associated with a higher likelihood of clear surgical margins when compared to laparoscopy.