Local Recurrence-Free Survival After TaTME: A Canadian Institutional Experience

BACKGROUND: Transanal total mesorectal excision is a novel surgical treatment for mid to low rectal cancers. Norwegian population data has raised concerns about local recurrence in patients treated with transanal total mesorectal excision. OBJECTIVE: Our objective was to analyze local recurrence and disease-free survival in patients treated by transanal total mesorectal excision for rectal cancer at a high-volume tertiary center. DESIGN: This is a retrospective study utilizing a prospectively maintained institutional transanal total mesorectal excision database. Patient demographics, treatment and outcomes data were analyzed. Local recurrence, disease-free, and overall survival were analyzed using Kaplan-Meier analysis. SETTINGS: The study was conducted at a single academic institution in Vancouver, Canada. PARTICIPANTS: All patients treated by transanal total mesorectal excision for rectal adenocarcinoma between 2014-2022 were included. MAIN OUTCOME MEASURES: The primary outcome was local recurrence-free survival. RESULTS: Between 2014 and 2022, 306 patients were treated by transanal total mesorectal excision at St. Paul’s Hospital. Of these, 279 patients met inclusion criteria. Mean age was 62 years (SD ± 12.3) and 66.7% of patients were male. Restorative resection was achieved in 97.5% of patients with a conversion rate from laparoscopic to open of 6.8%. Composite optimal pathological outcome was 93.9%. The median follow-up was 26 months (interquartile range 12 – 47) and 82.8% achieved reestablishment of gastrointestinal continuity to date. The overall local recurrence rate was 4.7% (n = 13). The estimated 2-year local recurrence-free survival was 95.0% (95% CI: 92 - 98) and 94.5% at 5 years (95% CI: 91 – 98). LIMITATIONS: Limitations include retrospective nature of the study and generalizability of a Canadian population. CONCLUSIONS: Recent European data has challenged the presumed oncologic safety of transanal total mesorectal excision. While the learning curve for this procedure is challenging and poor outcomes are associated with low volume, this high volume single-center study confirms acceptable oncologic outcomes consistent with the current standard. See Video