The anatomic characteristics of the fascias arounding rectum and its clinical significance

Objective: To provide anatomical foundation for TME(total mesorectal excision) used for treating rectal cancer. Methods: To dissect and measure structures of mesorectal, Denonvilliers fascia and the lacuna around rectum. Results: 1. The upper middle segment of Mesorectum which mostly contained a mass of fat tissue and presented loose linkage with rectum , while stretched out Fibrous bands and entered rectal floor was thicker than lower part. The lower part gradually thinned to 2.1±1.2 mm and there were mesenter with length of 1.59±0.47 cm tightly connecting with rectal muscle, as well its end was joined with levator ani by tight connective tissue. 2. Denonvilliers fascia was thin and tight, and the thinnest site was just 1.4±0.5 mm. 64% of the fascia stretched out Fibrous bands and entered the space between prostate and spermatophore (or vagina ) 3. There was no obvious Fascicles of side ligament of rectum. Conclusions: Mesorectal and Denonvilliers fascia were separate structures enwrapping rectum. It is possible to separate the integrated mesorectal sharply along the retrorectal space and the lateral of rectum completely. However, the separating process need to be cautious and careful for Denonvilliers fascia and prostate(vagina) as well as the nether mesenter of rectum and rectal floor are tightly joined.