Robotic Lateral Pelvic Lymph Node Dissection Could Harvest More Lateral Pelvic Lymph Nodes over Laparoscopic Approach for Mid-to-Low Rectal Cancer: A Multi-Institutional Retrospective Cohort Study

Lateral pelvic lymph node dissection (LPND) is a technically demanding procedure. This study aimed to compare the short-term outcomes of laparoscopic and robotic LPNDs. This multi-institutional retrospective study included 108 consecutive patients who underwent laparoscopic or robotic total mesorectal excision with LPND for locally advanced rectal cancer. There were 74 patients in the laparoscopic and 34 in the robotic groups. The median operation time was longer in the robotic group than in the laparoscopic group (353 vs. 275 min, p < 0.001). No patients underwent conversion to open surgery in either group. Pathological LPN metastases were observed in 24 and 8 patients in the laparoscopic and robotic groups, respectively (p = 0.347). Although the number of harvested mesorectal lymph nodes was similar (15.5 vs. 15.0, p = 0.968), the number of harvested LPNs was higher in the robotic than in the laparoscopic group (7.0 vs. 5.0, p = 0.004). Postoperative complications and length of hospital stay were similar (robotic vs. laparoscopic, 35.3% and 7 days vs. 37.8% and 7 days, respectively). Both laparoscopic and robotic LPND are safe and feasible for locally advanced rectal cancers, but robotic LPND showed more harvested lateral lymph node than laparoscopic LPND.