Outcomes of transanal total mesorectal excision with ultra-low anterior resection: A single institute propensity-matched cohort study.

Ultra-low anterior resection (ULAR) and total mesorectal excision (TME) are sphincter-preserving treatments for low rectal cancer. However, these techniques face challenges in patients with a narrow pelvis, particularly those with a high BMI. Transanal TME (TaTME) was introduced as a promising treatment approach, but outcomes have varied, leading to some controversy. The present study compared the mid-term oncological and postoperative outcomes, with a median follow-up time of 3.8 years, in patients who underwent TaTME with ULAR (TaTME cohort) or ULAR alone (ULAR cohort). A propensity-matched cohort of 78 patients (TaTME, n=19; ULAR, n=59) was analysed using descriptive statistics, Cox proportional hazard models and Kaplan-Meier survival analyses. Outcomes included progression-free survival (PFS), overall survival and surgical complications. The TaTME group exhibited a longer operative time (554 vs. 322 min; P=0.002) but no conversions to open surgery compared with 4 patients in the ULAR group. No cases of positive circumferential resection margins or anastomotic leakage were observed in the TaTME group. The rate of postoperative sexual dysfunction appeared higher in the TaTME group (3/16 vs. 1/58; P=0.043); however, the absolute number of cases was small and this finding should be interpreted with caution. No other postoperative complications, including anastomotic leak, sepsis or ileus, differed significantly between groups. There was no significant difference in the 3-year PFS rate between the TaTME and ULAR groups (88 vs. 70%; P=0.080) nor in the disease-free survival rate (88 vs. 80%; P=0.259). The TaTME cohort also demonstrated lower risks of recurrence and mortality, although these were not statistically significant. Therefore, TaTME with ULAR appears feasible for patients with low rectal cancer and high BMI, with encouraging surgical outcomes. However, due to the limited sample size and absence of stage IV patients in the TaTME group, more multicentre studies are required to validate long-term efficacy and generalisability.