Transanal versus laparoscopic total mesorectal excision for mid and low rectal cancer: a meta-analysis of short-term outcomes

Introduction
The benefit of transanal total mesorectal excision (TaTME) for mid and low rectal cancer is conflicting.

Aim
To assess and compare the short-term outcomes of TaTME with conventional laparoscopic total mesorectal excision (LaTME) for middle and low rectal cancer.

Material and methods
We searched PubMed, Embase and Cochrane Library databases for studies addressing TaTME versus conventional LaTME for rectal cancer between 2008 and December 2018. Randomized controlled trials (RCTs) and retrospective studies which compared TaTME with LaTME were included.

Results
Twelve retrospective case-control studies were identified, including a total of 899 patients. We did not find significant differences in overall intraoperative complications, blood loss, conversion rate, operative time, overall postoperative complication, anastomotic leakage, ileus, or urinary morbidity. Also no significant differences in oncological outcomes including circumferential resection margin (CRM), positive CRM, distal margin distance (DRM), positive DRM, quality of mesorectum, number of harvested lymph nodes, temporary stoma or local recurrence were found. Although the TaTME group had better postoperative outcomes (readmission, reoperation, length of hospital stay) on average, the difference did not reach statistical significance.

Conclusions
Transanal total mesorectal excision offers a safe and feasible alternative to LaTME although the clinicopathological features were not superior to LaTME in this study. Currently, with the lack of evidence on benefits of TaTME, further evaluation of TaTME requires large randomized control trials to be conducted.