Defining the learning curve of transanal total mesorectal excision: a systematic review and meta-analysis

Background Transanal total mesorectal excision (taTME) represents a novel approach to rectal dissection. Although many structured training programs have been developed worldwide to assist surgeons in implementing this new technique, the learning curve (LC) of taTME has yet to be conclusively defined. This is particularly important given the concerns regarding the complication profile and oncological safety of taTME. The aim of this review was to provide an up-to-date systematic review and meta-analysis of the LC for taTME, comparing the difference of outcomes between the LC and after learning curve (ALC) groups. Methods An up-to-date systematic review was performed on the available literature between 2010-2020 on PubMed, EMBASE, Medline and Cochrane Library databases. All studies comparing taTME procedures before and after LC were analysed. Results Seven retrospective studies of prospectively collected databases were included, comparing 333 (51.0%) patients in the LC group and 320 (49.0%) patients in the ALC group. There was a significantly reduced number of adverse intra-operative events, anastomotic leaks and improved quality of mesorectal excision in the ALC group. Conclusion This review shows that there is a significant improvement in clinical outcomes between the LC and ALC groups which supports the need for careful mastery and ongoing technical refinement during the LC in taTME. This procedure should be performed on a subset of carefully selected patients in the hands of experienced and well-trained teams dedicated to ongoing audit.