Comparing efficacy and safety of transanal vs. laparoscopic total mesorectal excision for middle and low rectal cancer: Updated meta-analysis

Objective: This study aimed to compare the efficacy and safety of transanal total mesorectal excision (TaTME) with laparoscopic total mesorectal excision (LaTME) in patients with middle and low rectal cancer. Methods: A comprehensive search of PubMed, Embase, and Cochrane databases was conducted to identify studies evaluating TaTME and LaTME from inception to June 2023. An additional search update was conducted in November 2024 to capture recently published studies. A total of 24 studies (3 randomized controlled trials and 21 observational studies) involving 3443 patients were included. Meta-analysis assessed key outcomes, including circumferential resection margin (CRM) positivity, R0 resection rate, completeness of mesorectal excision, conversion to open surgery, and postoperative complications. Results: TaTME was associated with a significantly lower positive rate of CRM (odds ratio [OR] = 0.68, 95 % confidence interval [CI] = 0.49-0.94), a higher R0 resection rate (OR = 1.74, 95 % CI = 1.17-2.59), and a reduced incidence of conversion to open surgery (OR = 0.16, 95 % CI = 0.10-0.26) compared to LaTME. Completeness of ME was comparable between the two groups (OR = 1.29, 95 % CI = 0.85-1.96). There was no significant difference in postoperative complications (OR = 0.80, 95 % CI = 0.62-1.03) or 30-day mortality (OR = 0.42, 95 % CI = 0.12-1.47). Conclusions: TaTME demonstrates superior outcomes in terms of CRM positivity, R0 resection, and conversion rates compared to LaTME, with comparable safety profiles and no significant differences in postoperative complications or 30-day mortality. These findings support TaTME as a viable surgical approach for middle and low rectal cancer.