Endopelvic 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
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The
anatomical compartments and their connections as demonstrated by ectopic air. Anastomotic colorectal leak during a CT colonoscopy in a 81-year-old woman with a history of excision of recto-sigmoid adenocarcinoma 8 years previously. Coronal (a) and sagittal (b) reformatted CT scan. Continuity of the transversalis fascia with the parietal endopelvic fascia is depicted
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Endopelvic fascia

The endopelvic fascia is the enveloping connective tissue network for the pelvic viscera, suspending, supporting and fusing the pelvic organs to the arcus tendineus fasciae pelvis, which itself inserts onto the pelvic sidewalls and pubic bones.

The major anterior component is the pubovesical ligaments, attaching between the pubic symphysis, bladder and anterior vaginal wall. Posteriorly, the major component is the rectovaginal fascia between the anterior rectal wall and the posterior wall of the vagina.

Three levels of endopelvic fascial support have been described:

  • level 1 suspends the upper portion of the vagina and the uterine cervix
  • level 2 supports the middle portion of the vagina and the posterior bladder wall
  • level 3 attaches the lower portion of the vagina to the perineal membrane, and also includes the urethral suspensory ligaments 

The fascia cannot be seen on imaging, but damage to the fascia can be inferred by the presence of various signs. The upper third of the vagina usually has a horizontal appearance, but in the event of damage to the level 1 fascia, the lateral support is lost and the vagina may have an inverted V shape, known as the chevron sign. The middle third of the vagina usually has a H or W shape on axial imaging, and loss of the level 2 fascia along with puborectalis dehiscence, may lead to loss of the normal shape on one or both sides. Loss of the paravaginal ligaments leads to loss of support of the posterolateral aspect of the bladder and the saddlebag bladder sign. Damage to the pubovesical ligaments and rectovaginal fascia may also lead to the development of cystoceles and rectoceles, respectively. Finally, damage to the level 3 fascia and the periurethral ligaments leads to posterior drooping of the lateral corners of the retropubic fat, leading to the drooping moustache sign.