The anatomic basis of total mesorectal excision.

Background: Total mesorectal excision is considered the gold standard for rectal cancer surgery, but the anatomic descriptions and nomenclatures that are used are hardly clear and sometimes are contradictory. The aim of this study was to clarify the delimitation of the mesorectum and anatomic landmarks of the correct surgical plane for total mesorectal excision.

Methods: Cadaveric dissections were performed on 32 pelvises.

Results: The pelvic fasciae around the rectum can be divided into visceral fascia, vesicohypogastric fascia, and parietal fascia. The lateral ligament is the dense connective tissue between the rectum and visceral fascia instead of the pelvic sidewall. There are 2 different fascial envelopes around the rectum. The diffusion type of pelvic plexus is difficult to separate from the visceral fascia.

Conclusions: The autonomic nerves and lateral rectal ligament can be distinguished as the landmark to judge the different planes. The correct surgical plane of posterior dissection is conducted between the visceral fascia and parietal fascia, and anterolateral dissection is conducted between the vesicohypogastric fascia and parietal fascia.