Laparoscopic Versus Robotic Lateral Pelvic Lymph Node Dissection in Locally-Advanced Rectal Cancer: A Cohort Study Comparing Perioperative Morbidity and Short-Term Oncological Outcomes.

Background: Robotic surgery has been associated with superior short-term outcomes in patients undergoing total mesorectal excision (TME) for organ-confined rectal cancer. However, whether this approach offers an additional benefit over laparoscopy when performing lateral pelvic lymph node dissection (LPLND) with TME or extended TME (e-TME) in locally advanced rectal cancer (LARC) is not known.

Aims: This study was conducted to evaluate the outcomes of robotic and laparoscopic LPLND in patients with lateral pelvic node-positive LARC with reference to intraoperative safety, postoperative morbidity, pathological indices including nodal yield and node positivity rates, lateral pelvic recurrence rates, and short term event-free and overall survival.

Methods And Results: In this retrospective single-center study, consecutive patients with non-metastatic histologically proven LARC and clinically significant lateral pelvic lymphadenopathy who had undergone laparoscopic or robotic LPLND with TME or e-TME between 2014 and 2023 were included, all procedures having been performed by minimal-access colorectal surgeons who were beyond the learning curve for either surgical approach. Of the 115 patients evaluated, 98.3% received neoadjuvant chemoradiotherapy, following which 27 (23.5%) underwent robotic and 88 (76.5%) laparoscopic LPLND with TME or e-TME. The baseline clinicodemographic features, treatment-related characteristics, and proportion of patients undergoing extended resections for persistent circumferential resection margin-positive rectal cancer (22.7% vs. 18.5%, respectively) were statistically similar in both groups. When comparing robotic with laparoscopic resections, no significant difference was observed in intraoperative parameters including procedure-associated blood loss (median 250 mL vs. 400 mL) and on-table adverse events or conversion rates (none in either group), postoperative outcomes comprising clinically significant early (14.8% vs. 9.1%), intermediate (5.3% vs. 1.9%) and late (5.3% vs. 2.0%) surgical morbidity, re-exploration rates (7.4% vs. 3.4%) and duration of hospital stay (median 6 days in both groups), or the pathological quality indices of margin involvement (7.4% vs. 2.3%), nodal yield (median 4 vs. 7 nodes) and lateral node positivity (22.2% vs. 26.1%), respectively. At a median 11 months follow-up, oncological outcomes in terms of lateral pelvic recurrence rates (3.7% vs. 4.5%), 2-year event-free survival (78.7% vs. 79.3%) and 2-year overall survival (83.1% vs. 93.8%) were also comparable.

Conclusion: Surgical competence in laparoscopy may offset the potential benefits extended by robotic platforms. In a high-volume setup with experienced minimal-access surgeons, the clinical, pathological, and short-term oncological outcomes associated with both approaches may be considered equivalent.