David Lisle, Alodia Gabre-Kidan, Ravi Pasam, Daniel Feingold, P Ravi Kiran, Steven Lee-Kong. Columbia University Medical Center
Purpose: Colorectal cancer is the third most common cancer in males and second in females world wide with an incidence of 1.2 million new cases and 608,700 deaths in 2008. There appears to be a positive correlation between number of lymph nodes resected and survival in colon cancer. Minimally invasive colectomies are gaining acceptance and laparoscopy is becoming standard treatment for elective colorectal resection. The field of robotic surgery is, also growing and now extends to colorectal procedures. Few studies have compared the effectiveness of lymph node sampling in robotic vs laparoscopic surgery in colorectal cancer.
Methods: A restrospective review at NYP-Columbia medical Center EMR between September 2012 and July 2014. We compared lymph node dissection in patients who underwent robotic vs laparoscopic colorectal resection performed by the PI. The primary endpoint included total number of sampled lymph nodes. Separate subgroup analysis looking at right colon, sigmoid colon and rectal resections comparing primary endpoints was also done.
Results: Between September 2012 and July 2014 the PI performed 51 colorectal resections for malignancy. 31 patients had robotic resections and 25 underwent laparoscopic resection. The mean age at diagnosis of the laparoscopic group was 69 vs 59 in the robotic group (t-value: -2.4; p-value 0.02). The groups were similar in gender (lap 56% female vs robotic 52% female) and BMI (lap mean BMI: 28; robotic mean BMI; p-value: 0.73).
When looking at all colorectal surgeries, the mean number of lymph nodes sampled was equivalent when comparing robotic versus laparoscopic approaches (28 vs 24; P=0.31). Similarly, in subgroup analysis looking at right colectomy, sigmoid colectomy and rectal resection separately no difference in number of LN’s sampled was found when comparing laparoscopic vs robotic surgery.
Conclusion: Colorectal consensus guidelines recommend a minimum of 12 lymph node sampling in order to accurately stage cancer. In addition, there is a survival benefit directly correlating to the number of nodes sampled. In our experience both robotic and laparoscopic surgery meet and surpass the minimum standards for lymph node resection. Robotic surgery appears to be a viable alternative to laparoscopy in regards to number of lymph nodes sampled. Further randomized controlled trials are necessary in order to confirm these results and to better understand how robotic vs laparoscopic lymph node sampling effects recurrence and survival.