Laparoscopic Versus Open Lateral Lymph Node Dissection for Locally Advanced Low Rectal Cancer: A Subgroup Analysis of a Large Multicenter Cohort Study in Japan

BACKGROUND:Mesorectal excision with lateral lymph node dissection is the standard treatment for locally advanced low rectal cancer in Japan. However, the safety and feasibility of laparoscopic lateral lymph node dissection remain to be determined. OBJECTIVE:The purpose of this study was to evaluate the safety and feasibility of laparoscopic versus open lateral lymph node dissection for locally advanced low rectal cancer. DESIGN:This was a retrospective cohort study using an exact matching method. SETTING:We conducted a multicenter study of 69 specialized centers in Japan. PATIENTS:Patients with consecutive midrectal or low rectal adenocarcinoma cancer stage II to III who underwent mesorectal excision with curative intent between 2010 and 2011 were recruited. MAIN OUTCOME MEASURES:Short-term and oncological outcomes were compared between the laparoscopic and open-surgery groups. RESULTS:Of the 1500 eligible patients, 676 patients who underwent lateral lymph node dissection were analyzed, including 137 patients who were treated laparoscopically and 539 patients who were treated with open surgery. After matching, the patients were stratified into laparoscopic (n = 118) and open-surgery (n = 118) groups. Operative times in the overall cohort were significantly longer (461 vs 372 min) in the laparoscopic versus the open-surgery group. In the laparoscopic group, the blood loss volume was significantly smaller (193 vs 722 mL), with fewer instances of blood transfusion (7.3% vs 25.5%) compared with the open-surgery group. The postoperative complication rates were 35.8% and 43.6% for the laparoscopic and open-surgery groups (p = 0.10). The 3-year relapse-free survival rates were 80.3% and 72.6% for the laparoscopic and open-surgery groups (p = 0.07). LIMITATIONS:The study was limited by its retrospective design and potential selection bias. CONCLUSIONS:Laparoscopic lateral lymph node dissection is safe and feasible for cancer stage II to III low rectal cancer and is associated with similar oncological outcomes as open lateral lymph node dissection. See Video Abstract at http://links.lww.com/DCR/A334.