[Investigation on the integrity of mesorectal specimens of transanal total mesorectal excision].

Total mesorectal excision (TME) has become the gold standard for mid-low rectal cancer surgery. However, for some patients with obesity and narrow pelvis, there are great challenges in both open and laparoscopic surgery. Transanal total mesorectal excision (taTME) uses a transanal approach, in " bottom-up" direction, which reduces the difficulty of distal mesorectal excision and may improve the quality of the TME specimen. The taTME provides a direct sight of the tumor and the distal resection margin is more precise. However, whether taTME can achieve complete total mesorectal excision, especially for mid-rectal cancer, is still controversial. This study compares the quality and integrity of mesorectum among open surgery, laparoscopic surgery, and taTME surgery according to TME principles and quality evaluation criteria of TME specimen. In conclusion, the integrity of mesorectum of taTME specimens for low-rectal cancer is good. But for the mid-rectal cancer, the integrity of mesorectum of taTME specimens and long-term efficacy are still controversial and need high-level evidence support.