Benjamin Hopkins, MD, Timothy M Geiger, MD, Molly M Ford, MD, Roberta L Muldoon, MD, Alva J Bethurum Jr., Alexander T Hawkins, MD, MPH. Vanderbilt University Medical Center
INTRODUCTION: Margin negative resection of rectal cancer with minimally invasive techniques remains technically challenging. Robotic surgery, with articulated instruments and improved visualization, has been offered as an advantage to traditional laparoscopy. We hypothesize that a robotic approach will be associated with a higher rate of negative margin resections when compared to a laparoscopic approach.
METHODS AND PROCEDURE: The National Cancer Database (2010-2014) was queried for adults with locally advanced rectal cancer (clinical stage II-III) who underwent neoadjuvant chemoradiation and curative resection to conduct an observational retrospective cohort study of a prospectively maintained database. Exclusion criteria included metastatic disease or an open surgical approach. Patients were grouped by either robotic (ROB) or laparoscopic (LAP) approach in an intent-to-treat analysis. The primary outcome was negative margin status, which was defined by using a composite of two factors including circumferential resection margin greater than 1 mm and distal margin without tumor. Multivariable regression analysis was used to examine the association between approach (robotic or laparoscopic) and margin, adjusting for patient, hospital and surgical factors. Secondary outcomes included length of stay, readmission and overall survival.
RESULTS: 7717 patients with locally advanced rectal cancer who underwent minimally invasive resection were identified over the study period. 2316 (30%) underwent an attempted robotic approach. Factors associated with robotic approach included male gender, private insurance, treatment in the mid-west region, treatment at an academic/ research program and abdominal perineal resection. The overall conversion rate was 12.4% and was increased in the laparoscopic group (ROB: 7.7% vs LAP: 15.2%); p<0.001). The was no difference in unadjusted composite negative margin rate (ROB: 93.6% vs LAP: 92.9%; p=0.23). In an adjusted analysis controlling for patient, hospital and procedural factors, robotic approach was not associated with a higher composite negative margin status (OR 0.88; 95% CI 0.73-1.07; p=0.22). In adjusted analyses of secondary outcomes, there was no difference between approach in readmission (OR 1.07; 95% CI 0.90-1.27; p=0.44) or 5-year overall survival (HR 1.09; 95% CI 0.92-1.29; p=0.33). The robotic group had a small, but significant decrease in mean length of stay (ROB: 6.3d vs LAP: 6.7d; p<0.001).
CONCLUSION: This well powered analysis supports either a robotic or a laparoscopic approach for resection of locally advanced rectal cancer from a margin perspective. Both approaches appear to have similar readmission and 5-year overall survival rates. Patients undergoing robotic surgery have a 0.4 day decrease in mean length of stay.
Presented at the SAGES 2017 Annual Meeting in Houston, TX.
Abstract ID: 92764
Program Number: S058
Presentation Session: Colorectal II – Neoplasia
Presentation Type: Podium