mesorectal fascia

The
anatomical compartments and their connections as demonstrated by ectopic air. The same patient as in Fig. 13b. Fournier gangrene in a 67-year-old diabetic man, with extensive arteriosclerosis, already submitted to aortic bifemoral bypass years ago, still permeable (red circles – patent common femoral bypass grafts located anteriorly to native arteries, occluded on the left). Contrast-enhanced CT scan at level of acetabular dome shows endopelvic fascia and extraperitoneal pelvic spaces. Endopelvic fascia and its two layers are illustrated. The parietal layer covers the elevator muscle of anus and coccygeus (pelvic diaphragm) and the intrapelvic portions of the internal obturator and the piriformis muscles. The visceral layer covers inferior segments of the urinary bladder, lower third of the ureters, uterus, vagina and seminal vesicles; it forms a continuous line enveloping the perirectal fat, the mesorectal fascia. Pelvic spaces. Prevesical space is bordered by transversalis fascia anteriorly and umbilicovesical fascia posteriorly. Paravesical and presacral spaces are limited by parietal and visceral sleeves of the endopelvic fascia. Perivesical space is surrounded by umbilicovesical fascia and rectovesical septum. Perirectal space is involved by the rectal fascia and separated from the perivesical space by the rectovesical septum
insightsimaging.springeropen.com • Open Access
Radiopaedia • CC-by-nc-sa 3.0 • de

The mesorectal fascia is a layer of connective tissue enclosing the perirectal fat that surrounds the rectum. It is an important anatomical structure in rectal cancer staging, as it forms the circumferential resection margin for the non-peritonealised portion of the rectum.

Summary

  • location: envelopes the perirectal fat which surrounds the rectum within the pelvis
  • boundaries: extends from the beginning of the rectum to levator ani
  • contents: perirectal fat which contains the superior rectal artery and branches, superior rectal vein and tributaries, and lymph nodes and vessels

Gross anatomy

The mesorectal fascia begins at the rectosigmoid junction where it blends with the connective tissue of the sigmoid mesentery. It extends to the end of the rectum at levator ani. Laterally it extends around the rectum and perirectal fat and becomes contiguous anteriorly with the rectovesical fascia (Denonvilliers fascia). Posteriorly it fuses with the presacral fascia (Waldeyer fascia). Note that a variable circumference of the rectum is enveloped by the mesorectal fascia, owing to the fact that the peritoneum reflects off the anterior aspect of the middle and upper thirds of the rectum (see Figure 1).

Contents
  • encloses the perirectal fat which in turn contains:
    • superior rectal artery and branches
    • superior rectal vein and tributaries
    • lymph nodes and vessels
Relations

See also

Siehe auch:
Assoziationen und Differentialdiagnosen zu mesorektale Faszie:
pelvine
Kompartimente
insightsimaging.springeropen.com • Open Access