DEFINITION AND EPIDEMIOLOGY

It is estimated that more than 300,000 surgeries are performed to correct POP annually, at a cost of greater than $1 billion.¹ Furthermore, the number of patients seeking care for these disorders is expected to increase by 45% in the future.² Despite this high prevalence, POP is a poorly understood condition, and many of the accepted definitions are based on expert opinion and consensus rather than epidemiologic or clinical data. The American College of Obstetrics and Gynecology (ACOG) defines POP as the protrusion of pelvic organs into the vaginal canal.³ More specifically, in a terminology workshop convened by the National Institutes of Health (NIH) for researchers in female pelvic floor disorders, POP was defined as the descent of vaginal segments to within 1 cm of the hymen or lower.⁴ POP encompasses anterior and posterior vaginal prolapse as well as apical or uterine prolapse. Terms such as “cystocele” and “rectocele” are intentionally not used because they imply an unrealistic certainty as to the specific organs behind the vaginal wall at the time of physical examination.

It is important to note that, although most clinicians can recognize the extremes of normal support versus severe prolapse, most cannot objectively state at what point vaginal laxity becomes pathologic and requires intervention. There are limited data concerning the normal distribution of POP in the population and the correlations between symptoms and physical findings. In a study of 497 women, Swift demonstrated that the distribution of prolapse in a population exhibited a bell-shaped curve, with most women having stage I or II prolapse by the Pelvic Organ Prolapse Quantification (POPQ) classification system (discussed later) and only 3% having stage III prolapse.⁵ This signifies that, at baseline, most women have some degree of pelvic relaxation. However, these women are typically asymptomatic and develop symptoms only as their prolapse increases in severity.⁶ Therefore, even if POP is found on physical examination by the definition given, it may not be clinically relevant and may not require intervention if the patient is asymptomatic.

HISTORY

Although it has been shown previously that patients’ histories cannot be used alone to differentiate or diagnose different types of urinary incontinence,^7,⁸ less is known about the reliability of patients’ symptoms for diagnosing POP. Patients with POP may present with a plethora of symptoms relating to voiding, defecatory, and sexual dysfunction as well as symptoms directly associated with the prolapse, such as vaginal pressure and discomfort. Despite the few studies specifically addressing the association between reported symptoms and POP, the consensus in the literature seems to be that the severity of the prolapse is not necessarily associated with increased visceral symptomatology.

Vaginal prolapse in any compartment—anterior, apical, or posterior—can manifest as vaginal fullness, pain, and/or protruding mass. In a recent study by Tan and associates, the feeling of “a bulge or that something is falling outside the vagina” had a positive predictive value of 81% for POP, and the lack of this symptom had a negative predictive value of 76%.⁹ Not surprisingly, increased degree of prolapse, especially beyond the hymen, is associated with increased pelvic discomfort and visualization of a protrusion.¹⁰

Stress urinary incontinence and voiding difficulties can occur in association with anterior and apical vaginal prolapse. However, women with advanced degrees of prolapse may not have overt symptoms of stress incontinence, because the prolapse may cause a mechanical obstruction of the urethra, leading to a higher urethral closure pressure and thereby preventing urinary leakage.¹¹ Instead, these women may require vaginal pressure or manual replacement of the prolapse in order to accomplish voiding. They are therefore at risk for incomplete bladder emptying and recurrent or persistent urinary tract infections, and for the development of de novo stress incontinence after the prolapse is repaired. Patients who require digital assistance to void in general have more advanced degrees of prolapse.¹²

In addition to difficulty voiding, other urinary symptoms such as urgency, frequency, and urge incontinence, are found in women with POP.¹³ However, it is not clear whether the severity of prolapse is associated with more irritative voiding symptoms or bladder pain.^10,¹²

POP, especially in the apical and posterior compartments, can be associated with defecatory dysfunction, such as pain with defecation, the need for manual assistance with defecation, and anal incontinence of flatus, liquid or solid stool. These patients often have outlet-type constipation secondary to the trapping of stool within the rectal hernia, necessitating splinting or application of manual pressure in the vagina, rectum, or perineum to reduce the hernia and aid in defecation. Although defecatory dysfunction remains the area that is least understood in patients with POP, clinical and radiographic studies have shown that the severity of prolapse is not strongly correlated with increased symptomatology.^9,^10,^12,¹⁴

Although women with isolated posterior prolapse (e.g., rectocele, enterocele, perineal body defect) may also have the sensation of vaginal bulge and pressure, these women are often asymptomatic and the prolapse is recognized only on physical examination. Once a posterior vaginal defect is identified, questions regarding defecatory dysfunction must be elicited.

Although the relationship between sexual function and POP is not clearly defined, questions regarding sexual dysfunction must be included in the evaluation of any patient with POP. Patients may report symptoms of dyspareunia, decreased libido and orgasm, and increased embarrassment with altered anatomy that affects body image. Some studies have reported that prolapse adversely affects sexual functioning, with subsequent improvement in sexual function after repair of prolapse.¹⁵^–¹⁷ However, other studies have shown little correlation between the extent of prolapse and sexual dysfunction.¹² It is important to note that the evaluation of sexual function may be especially difficult in this patient population because the hindrances to sexual function may include factors other than POP, such as partner limitations and functional deficits.

PHYSICAL EXAMINATION

The physical examination for POP should be conducted with the patient in dorsal lithotomy position, as for a routine pelvic examination. If physical findings do not correspond to symptoms, or if the maximum extent of the prolapse cannot be confirmed, the woman can be reexamined in the standing position.

Initially, the external genitalia are inspected; if no displacement is apparent, the labia are gently spread to expose the vestibule and hymen. The integrity of the perineal body is evaluated, and the extent of all prolapsed parts is assessed. A retractor, a Sims speculum, or the posterior blade of a bivalve speculum may be used to depress the posterior vagina to aid in visualizing the anterior vagina, and vice versa for the posterior vagina. Because most patients with POP are postmenopausal, the vaginal mucosa should be examined for atrophy and thinning, which may affect management. Healthy, estrogenized tissue without significant evidence of prolapse, is well perfused and exhibits rugations and physiologic moisture. Atrophic vaginal tissue appears pale and thin, is without rugation, and can be friable.

After the resting vaginal examination, the patient is instructed to perform a Valsalva maneuver or to cough vigorously. During this maneuver, the order of descent of the pelvic organs is noted, as is the relationship of the pelvic organs at the peak of increased intra-abdominal pressure. A rectovaginal examination is also required to fully evaluate prolapse of the posterior vaginal wall and perineal body. Digital assessment of the contents of the rectovaginal septum during straining examination can differentiate between a “traction” enterocele (in which the posterior cul-de-sac is pulled down by the prolapsing cervix or vaginal cuff but is not distended by intestines) and a “pulsion” enterocele (in which the intestinal contents of the enterocele distend the rectovaginal septum and produce a protruding mass). Other clinical observations and tests to help delineate POP include cotton swab (Q-tip) testing for the measurement of urethral axis mobility; measurement of perineal descent; measurement of the transverse diameter of the genital hiatus or of the protruding prolapse; measurement of vaginal volume; description and measurement of posterior prolapse; and examination techniques differentiating among various types of defects (e.g., central versus paravaginal defects of the anterior vaginal wall). Inspection should also be made of the anal sphincter because fecal incontinence is often associated with posterior vaginal support defects. Grossly, women with a torn external sphincter may have scarring or a “dovetail” sign on the perineal body.

Anterior vaginal wall descent usually represents bladder descent with or without concomitant urethral hypermobility. However, in 1.6% of women with anterior vaginal prolapse, an anterior enterocele can mimic a cystocele on physical examination.¹⁸ Furthermore, lateral paravaginal defects, identified as detachment of the lateral vaginal sulci, may be distinguished from central defects, seen as a midline protrusion with preservation of the lateral sulci. This is done with the use of a curved forceps placed in the anterolateral vaginal sulcus and directed toward the ischial spine. Bulging of the anterior vaginal wall in the midline between the forcep blades implies a midline defect; blunting or descent of the vaginal fornices on either side with straining suggests lateral paravaginal defects. However, researchers have shown that the physical examination technique used to detect paravaginal defects is not particularly reliable or accurate. In a study by Barber and colleagues of 117 women with prolapse, the sensitivity of clinical examination to detect paravaginal defects was good (92%), yet the specificity was poor (52%).¹⁹ Despite a high prevalence of paravaginal defects, the positive predictive value was only 61%. Fewer than two thirds of the women believed to have a paravaginal defect on physical examination were confirmed to possess the same at surgery. Another study by Whiteside and associates, demonstrated poor reproducibility of clinical examination to detect anterior vaginal wall defects.²⁰ Therefore, the clinical value of determining the location of midline, apical, and lateral paravaginal defects remains unknown.

In regard to posterior defects, it has previously been demonstrated that preoperative clinical examinations do not always accurately differentiate between rectoceles and enteroceles.^21,²² Some investigators have advocated performing imaging studies to further delineate the exact nature of the posterior wall prolapse. Traditionally, most clinicians believe they are able to detect the presence or absence of these defects without anatomically localizing them. However, little is known regarding the accuracy or utility of clinical examinations in evaluating the anatomic locations of posterior vaginal defects. Burrows and colleagues found that clinical examinations often did not accurately predict the specific location of defects in the rectovaginal septum subsequently found intraoperatively.²³ Clinical findings corresponded with intraoperative observations in 59% of patients and differed in 41%; sensitivities and positive predicative values of clinical examinations were less than 40% for all posterior defects. However, what remains unclear is the clinical consequence of not detecting these defects preoperatively.

Clinical evaluation for POP also should include a lumbosacral neurologic evaluation consisting of strength, sensory, and reflex examinations. First, the strength of the pelvic floor musculature is assessed by palpating the levator ani muscle complex in the posterior vaginal wall approximately 2 to 4 cm cephalad to the hymen. The patient is then asked to squeeze around the exam-iner’s fingers. Weakness in this muscle can be a result of neurologic deficits or direct trauma during childbirth. Internal and external anal sphincter tone is assessed by placing a finger in the rectum and noting the initial resistance to entry and then the resistance after the patient maximally squeezes her anal sphincter. Sensory function is assessed with the use of pinprick and light-touch of the mons pubis, perineum/perianal area, and labia majora. Cystometry and anal manometry can be used to evaluate the visceral sensation of the bladder and rectum, respectively. Lastly, anal and bulbocavernosus reflexes can be elicited by lightly stroking the perianal skin and observing or palpating the contraction of the anal sphincter, and by lightly tapping the clitoris and observing the contraction of the bulbocavernosus muscle and/or anal sphincter.