Does previous transanal excision for early rectal cancer impair surgical outcomes and pathologic findings of completion total mesorectal excision? Results of a systematic review of the literature

Background: Transanal excision (TAE) is increasingly used in the treatment of early rectal cancer because of lower rate of both postoperative complications and postsurgical functional disorders as compared with total mesorectal excision (TME) OBJECTIVE: To compare in a meta-analysis surgical outcomes and pathologic findings between patients who underwent TAE followed by completion proctectomy with TME (TAE group) for early rectal cancer with unfavorable histology or incomplete resection, and those who underwent primary TME (TME group).

Methods: The Medline and Cochrane Trials Register databases were searched for studies comparing short-term outcomes between patients who underwent TAE followed by completion TME versus primary TME. Studies published until December 2016 were included. The meta-analysis was performed using Review Manager 5.0 (Cochrane Collaboration, Oxford, UK).

Results: Meta-analysis showed that completion TME after TAE was significantly associated with increased reintervention rate (OR=4.28; 95% CI, 1.10-16.76; P≤0.04) and incomplete mesorectal excision rate (OR=5.74; 95% CI, 2.24-14.75; P≤0.0003), as compared with primary TME. However there both abdominoperineal amputation and circumferential margin invasion rates were comparable between TAE and TME groups.

Conclusions: This meta-analysis suggests that previous TAE impaired significantly surgical outcomes and pathologic findings of completion TME as compared with primary TME. First transanal approach during completion TME might be evaluated in order to decrease technical difficulties.