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 such as the saddlebag bladder sign and the drooping moustache sign. 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. Damage to the pubovesical ligaments and rectovaginal fascia may also lead to the development of cystoceles and rectoceles, respectively.