Oncological outcomes of robotic-assisted laparoscopic versus open lateral lymph node dissection for locally advanced low rectal cancer

BackgroundThe long-term outcomes of robotic-assisted laparoscopic lateral lymph node dissection (RALLD) have not been fully investigated. This study aimed to assess the oncological and long-term outcomes of RALLD for rectal cancer through comparison with those of open lateral lymph node dissection (OLLD) in a retrospective study.MethodsBetween September 2002 and October 2014, the medical data of 426 patients who underwent total mesorectal excision with lateral lymph node dissection for primary rectal cancer were collected. Of these, 115 patients were excluded after data collection (stage IV, n=61; total pelvic exenteration, n=31; multiple cancer, n=20; conventional laparoscopic surgery, n=3). Before matching, 311 patients with clinical stage II/III were analyzed. Using exact matching, patients were stratified into RALLD (n=78) and OLLD (n=78) groups. Pathological findings and long-term outcomes were compared between the groups.ResultsThe pathological stage and number of harvested lymph nodes showed no significant differences between the groups. The rate of positive resection margin in the RALLD group tended to be lower compared with that of the OLLD group (p=0.059). The median follow-up duration was 54.0months in 156 patients. The 5-year overall survival rate was 95.4 and 87.8% in the RALLD and OLLD groups, respectively (p=0.106). The 5-year relapse-free survival rate was 79.1 and 69.9% in the RALLD and OLLD groups, respectively (p=0.157). The 5-year local relapse-free survival rate was 98.6 and 90.9% in the RALLD and OLLD groups, respectively (p=0.029).ConclusionsThe short- and long-term outcomes indicated that RALLD may be a useful modality for locally advanced low rectal cancer.