Whether the transanal total mesorectal excision can achieve a real total mesorectal excision

The total mesorectal excision (TME) developed by Heald in 1982, is the present gold standard treatment of middle and low rectal cancer. However, traditional transabdominal TME remains a technically demanding procedure in patients with a narrow pelvis, bulky tumors, or obesity. To overcome the technical difficulties associated with transabdominal rectal dissection, transanal total mesorectal excision (TaTME) has recently been introduced. However, can TaTME achieve comparable outcomes in comparison with transabdominal TME? Is the distal margin of the mesorectum sufficient? Where is the sign of distal margin of mesorectum? Can the circumferential margin (CRM) and specimen quality be guaranteed? The aim of this comment was to discuss whether the TaTME can achieve a real TME from the following aspects: the principles of transabdominal TME, current published TaTME clinical trials, and the anorectal and pelvic anatomy. Key words: Rectal neoplasms; Total mesorectal excision; Transanal total mesorectal excision; Terminal line