Transanal total mesorectal excision the Gold Coast experience: learning curve and comparison to traditional technique

Laparoscopic and open techniques in rectal cancer are well-published, however, technical challenges remain for mid to low rectal cancer resections in the narrow pelvis. Transanal total mesorectal excision (taTME) has been pioneered to potentially circumvent these challenges. The aims of this study were to evaluate the learning curve associated with our first cases of taTME as well as compare outcomes to that of conventionally performed rectal resections.

This was a single-centre retrospective study with data collated from all elective resections by the colorectal unit from 2015 to 2017. Primary outcome was completeness of total mesorectal excision and secondary outcomes were intra- and post-operative morbidity and mortality.

A total of 43 patients were identified. Of which, 20 underwent taTME. Mesorectal completeness was obtained in only 47.4% in the taTME group compared to 78.3% in the anterior resection group (p = 0.115). 5.9% of patients in our taTME group had positive circumferential resection margin compared to nil in the anterior resection. Conversion rates were greater in the taTME group (15% versus 0%; 0.028). Operative time, length of stay and clavien IV and V complications were greater in the taTME group.

This study highlights the difficulty in introducing a novel technique given the learning curve. Our results would expect to improve with increased caseload.