The Oncologic Outcomes of Inferior Mesenteric Artery-Preserving Laparoscopic Lymph Node Dissection for Upper-Rectal or Sigmoid Colon Cancer

Background: The standard procedure of lymph node (LN) dissection for rectal or sigmoid colon cancer remains controversial. Many laparoscopic surgeons cut the inferior mesenteric artery (IMA) at the root; however, this may cause bowel ischemia around the site of anastomosis. We performed D3 or D2 LN dissection with the preservation of the IMA. The aim of this study was to evaluate the oncologic outcomes of IMA-preserving LN dissection. Patients and Methods: We retrospectively analyzed 142 consecutive patients with upper-rectal or sigmoid colon cancer who underwent laparoscopic LN dissection with the preservation of the IMA. The number of LNs dissected and the overall and disease-free survival rates were retrospectively evaluated. Results: Laparoscopic D3 (n=92) or D2 (n=50) LN dissection were performed with the preservation of the IMA. The left colic artery was preserved in all cases, the superior rectal artery was also preserved in 30 cases. The mean number of LNs dissected was 19.6 in the D3 group and 12.9 in the D2 group. The median operative time was 230 minutes, and the median volume of blood loss was 17mL. There was no treatment-related mortality. The estimated 5-year disease-free survival rates of the stage I, II, and III patients were 93%, 83%, and 74%, respectively. No patients developed LN recurrence. Conclusions: Laparoscopic surgery with IMA-preserving LN dissection is an oncologically acceptable treatment strategy in patients with upper-rectal or sigmoid colon cancer.