Comparison of transanal total mesorectal excision and robotic total mesorectal excision for low rectal cancer after neoadjuvant chemoradiotherapy

Background: To improve the quality of surgery for rectal cancer, both transanal total mesorectal excision (taTME) and robotic total mesorectal excision (R-TME) can be performed. However, few studies have compared outcomes of taTME and R-TME, especially for patients with low rectal cancer after undergoing neoadjuvant chemoradiation (nCRT). Thus, the objective of this study was to compare outcomes of taTME and R-TME for patients with low rectal cancer after undergoing nCRT. Methods: A total of 306 consecutive patients with low rectal cancer who underwent taTME or R-TME after nCRT between 2008 and 2018 were analyzed retrospectively. Patients were classified into two groups: 1) taTME surgery group (n = 94); and 2) R-TME surgery group (n = 212). Results: Clinicopathologic variables were comparable between the two groups. There was no significant difference in circumference margin involvement (1.1% in taTME vs. 2.8% in R-TME, p = 0.680) or distal resection margin (2.3 cm in taTME vs. 2.4 cm in R-TME, p = 0.629). Total operation time (239 min in taTME vs. 243 min in R-TME, p = 0.675) and major complications (including anastomosis site leakage, surgical site infection, and voiding difficulty) showed no significant difference between the two groups either. Conclusions: Transanal and robotic TMEs have similar short-term outcomes for patients with rectal cancer after undergoing nCRT. High quality TME can be equally achieved with both transanal and robotic approaches.