Robotic Versus Laparoscopic Intersphincteric Resection for Low Rectal Cancer: Comparison of the Operative, Oncological, and Functional Outcomes

Background: Robotic surgery was developed to overcome the limitations of laparoscopic surgery and is increasingly used to treat low rectal cancer. In this study, we compared the operative, oncological, and functional outcomes of low rectal cancer patients who underwent robotic or laparoscopic intersphincteric resection (ISR). Methods: Prospectively collected data from low rectal cancer patients who underwent laparoscopic or robotic ISR between September 2006 and August 2011 were retrospectively compared. The functional outcomes of patients followed up for ≥12 months after ileostomy closure were evaluated via questionnaire. Results: Forty-four and 26 patients underwent robotic and laparoscopic ISR, respectively. The robotic group patients had a higher body mass index (BMI; 21.42 ± 3.13 vs. 24.13 ± 3.33 kg/m; p = 0.001), more advanced clinical N stage (p = 0.029), lower cancer location (3.71 ± 0.89 vs. 3.24 ± 0.78 cm; p = 0.023), more frequent chemoradiotherapy (26.9 vs. 54.5 %; p = 0.025), and longer operation time (286.77 ± 51.46 vs. 316.43 ± 65.11 min; p = 0.038). However, no intergroup differences were observed in the pathological details (except the number of retrieved lymph nodes), postoperative morbidity, 3-year overall survival, recurrence-free survival (RFS), local RFS, and functional outcomes. Conclusions: Robotic and laparoscopic ISR yielded similar operative, oncological, and functional outcomes in patients with low rectal cancer, despite differences in unfavorable outcome-affecting factors, including BMI, clinical N stage, cancer location, and chemoradiotherapy frequency. A randomized trial will provide more solid methodology for investigating the potential benefits of robotic ISR.