Lateral lymph node dissection via robotic surgery: technical feasibility and patterns of lateral lymph node recurrence in rectal cancer

Background Total mesorectal excision (TME) with bilateral lateral lymph node dissection (BLLND) is a standard surgical approach for low advanced rectal cancer (LARC) in Eastern countries. Although robotic surgery has been increasingly adopted for rectal cancer, its impact on lateral lymph node recurrence (LLNR) after BLLND remains unclear. Methods We retrospectively reviewed 180 patients with pathological stage II/III LARC who underwent TME with BLLND between 2009 and 2019. Of these, 149 patients underwent open surgery and 31 underwent robotic surgery. Perioperative outcomes, long-term oncological outcomes, and patterns of LLNR were compared between the two groups. Results Robotic surgery was associated with a significantly longer operative time but resulted in markedly reduced blood loss, lower rates of wound infection and anastomotic leakage, and a shorter postoperative hospital stay compared with open surgery (p ' 0.0001, p ' 0.0001, p ' 0.0001, p = 0.02, and p = 0.003, respectively). There were no significant differences between the two groups in 5-year overall survival or disease-free survival (p = 0.25 and p = 0.11, respectively). Notably, LLNR was observed exclusively in the open surgery group (16 patients), whereas no cases of LLNR occurred in the robotic surgery group. Recurrence sites in the open group were predominantly located in the distal internal iliac region (263D), followed by the proximal internal iliac (263P) and obturator (283) regions. Conclusion Robotic TME with BLLND demonstrated favorable short-term outcomes and technical feasibility; however, definitive oncological superiority could not be established.