Prolaps Organ Pelvis

01Pathophysiology

The pelvic organs (bladder, uterus, vaginal vault, rectum) are maintained in their anatomical position by an integrated support system composed of the levator ani muscle complex (particularly the pubococcygeus and iliococcygeus), the endopelvic fascia, and the uterosacral-cardinal ligament complex. DeLancey's three levels of vaginal support provide the conceptual framework:

Level I refers to the superior suspension of the upper vagina and cervix by the cardinal and uterosacral ligaments, anchoring them to the sacrum and lateral pelvic sidewall. Failure at this level leads to uterine prolapse or vaginal vault prolapse (in post-hysterectomy patients).

Level II involves lateral attachment of the mid-vagina to the arcus tendineus fasciae pelvis (white line) and the fascia overlying the levator ani. Damage here results in cystocele (anterior wall prolapse, bladder herniating into the vagina) or rectocele (posterior wall prolapse, rectum herniating into the vagina).

Level III is the distal fusion of the vagina to the perineal body posteriorly and the urethra anteriorly. Disruption causes perineal body defects and contributes to deficient urethral support.

Vaginal childbirth is the single most important inciting event. During delivery, the pudendal nerve (S2-S4) can be stretched or compressed, leading to denervation of the levator ani. Simultaneously, direct mechanical trauma to the fascial and muscular supports occurs, particularly with prolonged second stage of labor, macrosomia, and operative vaginal delivery (forceps more than vacuum). Over time, estrogen deficiency after menopause accelerates tissue atrophy in these already-weakened structures, explaining why symptomatic prolapse most commonly manifests years to decades after the initial childbirth injury.

The symptoms directly follow the anatomy. A cystocele compresses or kinks the urethra, causing urinary retention, frequency, or stress incontinence. A rectocele creates a pocket that traps stool, causing difficulty evacuating and the need to digitally splint (press on the posterior vaginal wall to assist defecation). Uterine prolapse causes the classic sensation of a mass or heaviness. All symptoms characteristically worsen with gravity and Valsalva (prolonged standing, end of day, lifting) and improve with lying down.

An important concept is occult stress urinary incontinence. A large cystocele can kink the urethra so severely that it actually masks stress incontinence. When the prolapse is reduced (manually or with a pessary), the kinking is relieved and the patient may suddenly develop or worsen stress incontinence. This must be tested for before surgical prolapse repair to counsel the patient and plan a concurrent anti-incontinence procedure if needed.

02Classification and Clinical Manifestation

POP-Q Staging System

The Pelvic Organ Prolapse Quantification (POP-Q) system is the standardized, objective measurement system. It uses the hymen as the fixed reference point (defined as 0). Points measured above (proximal to) the hymen are negative values; points below (distal to, i.e., protruding beyond) the hymen are positive values.

Stage IV (procidentia) deserves special attention. The entire uterus, cervix, and vaginal walls are everted and protrude outside the body. The exposed vaginal mucosa can become ulcerated, thickened, and keratinized. This is a surgical indication, and the mucosa must be assessed for ulceration and possible malignancy before repair.

03Diagnostic Workup

Pelvic organ prolapse is fundamentally a clinical diagnosis. The single most important diagnostic maneuver is a pelvic examination performed while the patient performs a Valsalva maneuver. This reproduces the conditions under which the prolapse is symptomatic. Using a split speculum (the posterior blade alone retracts the posterior wall, allowing visualization of the anterior compartment, and vice versa) allows the examiner to isolate each compartment independently.

If the patient describes symptoms convincingly but the supine exam is unremarkable, a standing examination should be performed, as gravity can reveal prolapse that is not apparent in lithotomy.

The POP-Q system is used to objectively document the degree of prolapse. While the full nine-point measurement grid is rarely tested in detail, the concept that the hymen is the reference point (0) and that stages are defined by distance relative to the hymen is high-yield.

For patients with anterior compartment prolapse and urinary symptoms, a postvoid residual volume (by catheterization or bladder ultrasound) is essential. Elevated PVR suggests the cystocele is causing outlet obstruction. In patients being considered for surgical repair, urodynamic testing with the prolapse reduced (using a pessary or large swab to hold the prolapse in place) is performed to check for occult stress urinary incontinence, which would change the surgical plan.

In advanced prolapse (Stage III-IV), renal ultrasound should be obtained to rule out hydronephrosis, because the descent can kink one or both ureters. Any mucosal ulceration on a chronically prolapsed cervix or vaginal wall warrants biopsy to exclude malignancy.

04Management and Treatment

Conservative management is first-line for all patients with mild symptoms or those who are not surgical candidates. Pelvic floor muscle training (Kegel exercises) strengthens the levator ani and can reduce symptom severity in Stage I-II prolapse. These exercises must be performed correctly (isolating the pubococcygeus, not recruiting abdominal or gluteal muscles) and consistently for at least 12 weeks before benefit is expected.

Pessaries are the cornerstone of non-surgical management for symptomatic prolapse. The ring pessary is the most commonly used first-line device because it is easiest to insert and remove. For more advanced prolapse or when a ring pessary fails to stay in place, the Gellhorn pessary (a disc-and-stem device that creates suction against the vaginal walls) is used. Patients using pessaries require follow-up every 3 to 6 months for removal, cleaning, and inspection of the vaginal mucosa for erosion or ulceration. Topical vaginal estrogen (conjugated estrogen cream 0.5 g intravaginally 2-3 times weekly, or an estradiol ring) is commonly prescribed alongside pessary use, particularly in postmenopausal women, to maintain mucosal thickness and reduce the risk of pessary-related erosion.

Surgical options are considered when conservative measures fail or when the patient desires definitive correction:

For anterior compartment (cystocele): anterior colporrhaphy (anterior repair) plicates the pubocervical fascia to reinforce the anterior vaginal wall.

For posterior compartment (rectocele): posterior colporrhaphy (posterior repair) reinforces the rectovaginal septum.

For apical prolapse (uterine or vault): the choice depends on whether the uterus is in situ. If the patient has completed childbearing and desires definitive treatment, vaginal hysterectomy with uterosacral ligament suspension is a common approach. In post-hysterectomy vault prolapse, sacrocolpopexy (abdominal, often laparoscopic or robotic, using mesh to suspend the vaginal vault to the anterior longitudinal ligament of the sacrum) is considered the most durable repair with the lowest recurrence rate. An alternative vaginal approach is sacrospinous ligament fixation, which avoids abdominal surgery but has a higher anterior compartment recurrence rate.

For patients who are not sexually active and are poor surgical candidates, an obliterative procedure such as colpocleisis (partial or complete closure of the vaginal canal) offers a simpler, faster surgery with lower morbidity but eliminates the possibility of vaginal intercourse.

Synthetic mesh used in transvaginal prolapse repairs (as opposed to abdominal sacrocolpopexy) has been associated with significant complications including mesh erosion, pain, and dyspareunia. The FDA ordered manufacturers to stop distributing transvaginal mesh kits for prolapse repair. This is a frequently tested concept: transvaginal mesh for prolapse is no longer recommended, while abdominal sacrocolpopexy mesh remains an accepted and durable option.

05Differential Diagnosis and Distractors

06Traps and High-Yield Pearls

The most common way students lose points on prolapse questions is by failing to identify the correct compartment. A vignette describing a woman who needs to press on her posterior vaginal wall to complete a bowel movement is describing a rectocele (posterior compartment), not a cystocele. Conversely, a patient with urinary retention and a smooth anterior vaginal wall bulge has a cystocele (anterior compartment). The symptom tells you the compartment, and the compartment tells you the structure.

A second major trap involves occult stress incontinence. A patient with a large cystocele may report no urinary leakage. After prolapse repair, she develops new-onset stress incontinence. This is not a surgical complication; it is unmasking of pre-existing incontinence that was hidden by urethral kinking. The test-writer expects you to know that urodynamic testing with prolapse reduction should be done preoperatively.

Be alert for the vignette describing a postmenopausal woman with procidentia and an ulcer on the protruding cervix. The expected next step is biopsy to rule out malignancy, not immediate surgical repair. Never take a patient with an ulcerated prolapse to the operating room without tissue diagnosis.

Finally, remember the mesh distinction: transvaginal mesh for prolapse repair has been pulled from the market due to unacceptable erosion rates, but mesh used in abdominal sacrocolpopexy remains standard of care. A question that asks about the best surgical approach for post-hysterectomy vault prolapse in an otherwise healthy patient is looking for sacrocolpopexy, and you should not be deterred by concern about mesh complications, because the abdominal route carries a very different risk profile than the transvaginal route.

The core competency being tested is the ability to match the patient's symptoms and exam findings to the correct anatomical compartment, choose the appropriate level of intervention (observation, pessary, or surgery), and anticipate complications such as occult incontinence and mucosal ulceration in advanced disease.