Objective: This study aimed to determine local recurrence (LR) rate and pattern after transanal total mesorectal excision (TaTME) for rectal cancer. Background: TaTME for mid-and low rectal cancer has known a rapid and worldwide adoption. Recently, concerns have been raised on the oncological safety in light of reported high LR rates with a multifocal pattern. Methods: This was a multicenter observational cohort study in 6 tertiary referral centers. All consecutive TaTME cases for primary rectal adenocarcinoma from the first TaTME case in every center until December 2018 were included for analysis. Patients with benign tumors, malignancies other than adenocarcinoma and recurrent rectal cancer, as well as exenterative procedures, were excluded. The primary endpoint was 2-year LR rate. Secondary endpoints included patterns and treatment of LR and histopathological characteristics of the primary surgery. Results: A total of 767 patients were identified and eligible for analysis. Resection margins were involved in 8% and optimal pathological outcome (clear margins, (nearly) complete specimen, no perforation) was achieved in 86% of patients. After a median follow-up of 25.5 months, 24 patients developed LR, with an actuarial cumulative 2-year LR rate of 3% (95% CI 2-5). In none of the patients, a multifocal pattern of LR was observed. Thirteen patients had isolated LR (without systemic disease) and 10/13 could be managed by salvage surgery of whom 8 were disease-free at the end of follow-up. Conclusions and Relevance: This study shows good loco regional control after TaTME in selected cases from tertiary referral centers and does not indicate an inherent oncological risk of the surgical technique.

Background While a shift to minimally invasive techniques in rectal cancer surgery has occurred, non-inferiority of laparoscopy in terms of oncological outcomes has not been definitely demonstrated. Transanal total mesorectal excision (TaTME) has been pioneered to potentially overcome difficulties experienced when operating with a pure abdominal approach deep down in the pelvis. This study aimed to compare short-term oncological results of TaTME versus laparoscopic TME (lapTME), based on a strict anatomical definition for low rectal cancer on MRI. Methods From June 2013, all consecutive TaTME cases were included and compared to lapTME in a single institution. Propensity score-matching was performed for nine relevant factors. Primary outcome was resection margin involvement (R1), secondary outcomes included intra- and post-operative outcomes. Results After matching, forty-one patients were included in each group; no significant differences were observed in patient and tumor characteristics. The resection margin was involved in 5 cases (12.2%) in the laparoscopic group, versus 2 (4.9%) TaTME cases ( P = 0.432). The TME specimen quality was complete in 84.0% of the laparoscopic cases and in 92.7% of the TaTME cases ( P = 0.266). Median distance to the circumferential resection margin (CRM) was 5 mm in lapTME and 10 mm in TaTME ( P = 0.065). Significantly more conversions took place in the laparoscopic group, 9 (22.0%) compared to none in the TaTME group ( P < 0.001). Other clinical outcomes did not show any significant differences between the two groups. Conclusion This is the first study to compare results of TaTME with lapTME in a highly selected patient group with MRI-defined low rectal tumors. A significant decrease in R1 rate could not be demonstrated, although conversion rate was significantly lower in this TaTME cohort.

on behalf of the Dutch ColoRectal Cancer Audit Group 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 ¼ 416, lapTME, n ¼ 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 ¼ 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 ¼ 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.