Short-term Outcomes of Transanal versus Laparoscopic Total Mesorectal Excision: A Systematic Review and Meta-Analysis of Cohort Studies

Introduction: The TaTME surgery has been developed to overcome the difficulties encountered in the practice of laparoscopic surgery for rectal cancer, especially in male, obese patients with a narrow pelvis and mid and low rectal tumours. Although the TaTME shows some promising results regarding oncological and operative outcomes, some pitfalls have been indicated. Thus, the real benefits of this novel technique over the laparoscopic surgery remain unknown. The aim of the present study was to perform a systematic review and meta-analysis of the currently available literature on the outcomes of TaTME in comparison with laparoscopic procedure. Methods: A systematic literature search was conducted using the web-based databases MEDLINE, EMBASE, and Cochrane CENTRAL, followed by a manual search of the references of the initially identified articles. The study information, patient characteristics, oncological outcomes, perioperative outcomes, as well as short- and long-term postoperative outcomes were collected and critically evaluated. Results: Nine retrospective cohort studies were identified, comprising 751 patients (348 with TaTME, 403 with LaTME). The positive circumferential resection margin (P = 0.01) was better in patients treated with TaTME; whereas the quality of mesorectum, circumferential resection margin, distal resection margin, and harvested lymph nodes were comparable. The TaTME was associated with shorter operative time (P = 0.05; P = 0.0006 in subgroup analysis), less blood loss (P = 0.02), less conversion (P = 0.007), and shorter hospital stay (P = 0.06; P = 0.003 in subgroup analysis). The intraoperative complications were similar. As for the postoperative outcomes, the overall postoperative complications (P = 0.02) and the readmission (P = 0.003) were found less in patients treated with TaTME; however, the individual postoperative complications were found comparable. Conclusion: The present systematic review and meta-analysis suggested some advantages of TaTME, in terms of circumferential resection margin involvement, operative time, blood loss, conversion, hospital stay, overall postoperative complications, and readmission. It appears that the TaTME procedure achieved a better resection quality and smoother recovery in selected patients, without compromising the short- term safety. Nevertheless, it is too early to draw any conclusion, since results of high quality clinical evidence from randomized controlled trials have to be awaited. As it is technically demanding, the procedure needs to be taught and learned systematically to ensure safe implementation.