Laparoscopic lateral pelvic lymph node dissection is achievable and offers advantages as a minimally invasive surgery over the open approach

Laparoscopic lateral pelvic lymph node dissection (LPLD) is a minimally invasive alternative to open surgical therapy for advanced low rectal cancer patients. This study assessed potential risk factors for lateral pelvic lymph node metastasis (LPLM) and evaluated the feasibility and oncological safety of laparoscopic LPLD compared with the conventional open approach. We retrospectively reviewed the clinical records of 90 patients with advanced low rectal cancer who underwent LPLD following total mesorectal excision at Kyushu University Hospital between January 2001 and July 2014. We compared the clinicopathological features between the patients with and without LPLM and the surgical outcomes between patients who underwent laparoscopic LPLD (LL) and open LPLD (OL). Fourteen (15.6 %) patients had LPLM. Univariate analysis revealed that undifferentiated cancer, positive lymphatic invasion, > 50 % circumferential cancer extent, mesorectal lymph node metastases (MLM), and distant metastasis were associated with LPLM. In the multivariate analysis, MLM was the only independent risk factor for LPLM. Forty-six (51.1 %) patients underwent LL, and 44 (48.9 %) patients underwent OL. The mean surgical duration was longer in the LL group than in the OL group (641.0 vs. 312.0 min, P < 0.001). The LL group also had less hemorrhage (252.0 vs. 815.0 mL, P < 0.001) and a shorter hospital stay (22.9 vs. 29.1 days, P = 0.04) than the OL group. The mean number of harvested lateral pelvic lymph nodes was larger in the LL group than in the OL group (19.5 vs. 15.8, P < 0.05). The morbidity rate and overall survival (3-year OS: 94.7 vs. 82.9 %, P = 0.25) did not differ between the two groups. Patients with advanced low rectal cancer presenting MLM are good candidates for LPLD. Laparoscopic LPLD enables retrieval of more lymph nodes and may be acceptable for the treatment of advanced low rectal cancer.