What's new in the functional anatomy of pelvic organ prolapse?

Abstract

Purpose of Review Provide an evidence-based review of pelvic floor functional anatomy related to pelvic organ prolapse. Recent Findings Pelvic organ support depends on interactions between the levator ani muscle and pelvic connective tissues. Muscle failure exposes the vaginal wall a pressure differential producing abnormal tension on the attachments of the pelvic organs to the pelvic side-wall. Birth-induced injury to the pubococcygeal portion of the levator ani muscle is seen in 55% of women with prolapse and 16% of women with normal support. Failure of the connective tissue attachments between the uterus and vagina to the pelvic wall (cardinal, uterosacral, paravaginal) are strongly related with prolapse (effect sizes ~2.5) and are also highly correlated with one another (r ~0.85). Small differences exist with prolapse in factors involving the vaginal wall length and width (effect sizes ~1). The primary difference in ligament properties between women with and without prolapse is found in ligament length. Only minor differences in ligament stiffness are seen. Summary Pelvic organ prolapse occurs due to injury to the levator ani muscles and failure of the connections between the pelvic organs to the pelvic sidewall. Abnormalities of the vaginal wall fascial tissues may play a minor role.

Comparison of laparoscopic techniques for apical organ prolapse repair – a systematic review of the literature

“… Apical defect, the least frequent of all POP types, has been reported in 5%‐15% of women . DeLancey established three levels of support for proper position of the pelvic organs: Level I: uterosacral ligaments (damage: uterine/vaginal vault prolapse, enterocoele); Level II: pubocervical and rectovaginal fascia (damage: cystocele, rectocele); Level III: perineal membrane and perineal body (damage: urethrocele, perineal body defect/excessive perineal descent) …”

“…Level I: uterosacral ligaments (damage: uterine/vaginal vault prolapse, enterocoele); Level II: pubocervical and rectovaginal fascia (damage: cystocele, rectocele); Level III: perineal membrane and perineal body (damage: urethrocele, perineal body defect/excessive perineal descent). 8 The Integral Theory assumes sagittal support of the organs between the pubic symphysis and sacrum, including pubourethral ligaments and pubocervical fascia attached to the pericervical ring, which is then attached to uterosacral ligaments. 9,10 Pubocervical ligaments attach to the anterior, cardinal ligaments to the lateral, and uterosacral ligaments to the posterior parts of the pericervical ring.…”

Can We Evaluate Hiatal Ballooning by Measuring the Anteroposterior Diameter With 2‐Dimensional Translabial Ultrasonography?

“…An abnormal levator ani muscle is currently the best‐defined etiologic factor in the pathogenesis of prolapse. A weaker muscle increases pelvic floor muscle strain and abnormal distensibility of the levator hiatus, which are significantly related to POP . Levator ani avulsion injury is an avulsion of the puborectalis muscle from the pelvic side wall, which alters the pelvic floor muscle anatomy .…”

“…A weaker muscle increases pelvic floor muscle strain and abnormal distensibility of the levator hiatus, which are significantly related to POP. 8,[18][19][20] Levator ani avulsion injury is an avulsion of the puborectalis muscle from the pelvic side wall, which alters the pelvic floor muscle anatomy. 21,22 The hiatal area is an independent risk factor for POP and POP recurrence.…”

Using Z‐scores to evaluate levator hiatal dimensions with four‐dimensional translabial ultrasound

“…The levator hiatus is defined as the space enclosed by the levator ani muscle, which is the most important supporting tissue of the pelvic floor. To some extent, the levator hiatus dimensions reflect the biometry characteristics of the levator ani . There are obvious racial differences in female levator hiatal functional anatomy .…”