Transanal versus laparoscopic total mesorectal excision for mid and low rectal cancer (Ta-LaTME study): multicentre, randomized, open-label trial

Background: Transanal total mesorectal excision (TaTME) is a minimally invasive surgical technique that tries to avoid conversion to open surgery. However, specific intraoperative complications and local recurrences have cast some doubt on the suitability of the technique. The primary endpoint of the present study was a composite outcome of conversion surgery. Secondary objectives were to assess postoperative recovery, and pathological and oncological outcomes. Methods: This was a prospective, multicentre, randomized, controlled open-label study of patients diagnosed with mid and low rectal adenocarcinoma who underwent laparoscopic TaTME or laparoscopic total mesorectal excision (LaTME). The TaTME technique comprised intracorporeal resection and anastomosis. Main outcomes were conversion to open surgery. Secondary outcomes were postoperative morbidity, mortality, pathological, oncological results, and survival. Modified intention-to-treat (mITT) and per-protocol analyses were performed. Results: The study was conducted between April 2015 and May 2021. Patients were randomized to the LaTME (57 patients) or TaTME (59) group. Fifty patients from the LaTME group and 55 from the TaTME group were eligible for mITT analysis. The procedure was converted to open surgery in 11 patients (11 per cent): 10 (20 per cent) in the LaTME group and 1 (2 per cent) in the laparoscopic TaTME group (difference 18.8, 95 per cent c.i. 30 to 7; P = 0.003). No significant differences were found in terms of postoperative recovery and morbidity at 30 days; nor were there significant differences in anastomotic leakage, although it was less common in laparoscopic TaTME. With a median follow-up of 39 months, there were three instances of local recurrence (6.1 per cent) in the LaTME group and one (1.8 per cent) in the laparoscopic TaTME group (95 per cent c.i. 60 to 69; P = 0.3). Registration number: NCT02550769 (http://www.clinicaltrials.gov). Conclusion: The conversion rate was significantly lower in laparoscopic TaTME than in LaTME. At centres with experienced surgeons, laparoscopic TaTME can avoid conversion to open surgery.