To systematically evaluate the intraoperative and postoperative indicators, complications and pathological results of transanal total mesorectal excision (TaTME) and laparoscopic total mesorectal excision (LaTME) in the treatment of middle and low rectal cancer, and to analyze the feasibility and safety of TaTME.

The database both at home and abroad including Pubmed, EMBase, Cochrane Library, CNKI, Wanfang, VIP were searched between February 2015 and April 2019. All eligible studies associated with the treatment of middle and low rectal cancer with TaTME and LaTME were systematically analyzed. Newcastle-Ottawa Scale (NOS) and Revman 5.3 software were used to conduct Meta-analysis and sensitivity analysis of heterogeneous results.

A total of thirteen articles including 1 096 cases met the inclusion criteria, including 515 cases in group TaTME and 581 cases in group LaTME. Compared with group LaTME, group TaTME had longer CRM distance (MD=0.95, 95%CI=0.61-1.29, P<0.001), lower CRM positive rate (OR=0.35, 95%CI=0.16-0.78, P=0.010), higher quality TME (OR=2.41, 95%CI=1.29-4.51, P=0.006), lower rate of conversion to laparotomy (OR=0.20, 95%CI=0.07-0.58, P=0.003), Clavien-Dindo grade≥3 complications (OR=0.54, 95%CI=0.32-0.92, P=0.020), incidence of postoperative urination disorders (OR=0.54, 95%CI=0.31-0.94, P=0.030) and lower unplanned secondary admission (OR=0.44, 95%CI=0.27-0.73, P=0.001). There were no significant differences in DRM positive rate, resection distance, number of lymph node dissection, intraoperative blood loss, duration of operation, incidence of total complications, incidence of intestinal obstruction and anastomotic leakage between the two groups.

Compared with LaTME, TaTME can obtain higher specimens quality in the treatment of middle and low rectal cancer, the incidence of serious complications after operation is significantly reduced, and the operation is feasible and safe.