Three-Year Nationwide Experience with Transanal Total Mesorectal Excision for Rectal Cancer in the Netherlands: A Propensity Score-Matched Comparison with Conventional Laparoscopic Total Mesorectal Excision

Background: Transanal total mesorectal excision (TaTME) is a relatively new and demanding technique for rectal cancer treatment. Results from national datasets are absent and comparative data with laparoscopic TME (lapTME) are scarce. Therefore, this study aimed to evaluate the initial TaTME experience in the Netherlands, by comparing outcomes with conventional lapTME. Study Design: Patients with rectal cancer who underwent curative TaTME or lapTME were selected from the nationwide and mandatory Dutch ColoRectal Audit (DCRA), between January 2015 and December 2017. Primary outcome was circumferential resection margin (CRM) involvement. Secondary outcomes included operative details and short-term (<30 days) clinical course. Propensity score matching was performed for 7 factors. Results: There were 3,777 patients included for analysis (TaTME, n = 416, lapTME, n = 3361). Transanal TME was performed in 38 hospitals and lapTME in 90 hospitals. Before matching, the patient category within the TaTME group was technically more challenging in terms of tumor height and preoperative threatened margins. After 1:1 matching, 396 patients were included in each group, with comparable baseline characteristics. Circumferential resection margin involvement was 4.3% after TaTME and 4.0% after lapTME (p = 1.000). Conversion rate was significantly lower in TaTME (1.5% vs 8.6%, p < 0.001). Anastomotic leak rate was not significantly different (16.5% vs 12.2%, p = 0.116). Other postoperative outcomes were also comparable between the groups. Significant independent risk factors for CRM involvement in TaTME were preoperative threatened margin on MRI (odds ratio [OR] 5.48, 95% CI 1.33 to 22.54) and conversion (OR 30.12, 95% CI 3.70 to 245.20). Conclusions: This first nationwide study shows early experience with adoption of TaTME in the Netherlands. Considering that current data represent initial TaTME experience, acceptable short-term outcomes were demonstrated when compared with the well-established lapTME