Pelvic Floor Disorders: Pelvic Organ Prolapse, Urinary Incontinence, and Pelvic Floor Pain Syndromes

Anterior Vaginal Prolapse (Cystocele)

The anterior vagina is the most common site of vaginal prolapse. Women with this type of defect will describe symptoms of vaginal fullness, heaviness, pressure, and/or discomfort that often progress over the course of the day and are most noticeable after prolonged standing or straining. Women may have to apply manual pressure to empty their bladder completely. Other symptoms include stress urinary incontinence (SUI), urinary urgency, and frequency. Significant anterior vaginal wall prolapse that protrudes beyond the vaginal opening (hymen) can cause urethral obstruction caused by kinking, resulting in urinary retention or incomplete bladder emptying.

Posterior Vaginal Prolapse (Rectocele and Enterocele)

Posterior vaginal defects occur when there is weakness in the rectovaginal septum. Symptoms can be indistinguishable from other types of prolapse because the discomfort, pressure, and the sense of a vaginal bulge are nonspecific. When difficulties with bowel function and defecation occur, lower posterior vaginal prolapse is likely. Straining or the need to manually splint for complete bowel elimination may occur. Upper posterior vaginal wall prolapse is nearly always associated with herniation of the pouch of Douglas, and because this is likely to contain loops of bowel, it is called an enterocele .

Apical Vaginal Uterine Prolapse

Although vaginal prolapse can occur without uterine prolapse, the uterus cannot descend without carrying the upper or apical portion of the vagina with it.

Complete procidentia (uterine prolapse through the vaginal hymen) represents failure of all the vaginal supports ( Figure 23-2 ). Hypertrophy, elongation, congestion, and edema of the cervix may sometimes cause a large protrusion of tissue beyond the hymen that may be mistaken for a complete procidentia. Vaginal vault prolapse or eversion of the vagina may be seen after vaginal or abdominal hysterectomy and represents failure of the supports around the upper vagina.

Symptoms of POP mainly affect a woman's quality of life. However, significant sequelae of POP can occur in neglected cases of procidentia, which may be complicated by excessive purulent discharge, decubitus ulceration, and bleeding. Ureteral obstruction with hydronephrosis is also a possible result of complete procidentia.

Etiology of Prolapse

The pelvic fascia, ligaments, and muscles may become attenuated from excessive stretching during pregnancy, labor, and difficult vaginal delivery, especially with forceps or vacuum assistance. Asian and black women appear less likely than white women to develop prolapse.

Increased intraabdominal pressure resulting from a chronic cough, ascites, repeated lifting of heavy weights, or habitual straining as a result of constipation may predispose women to prolapse. Atrophy of the supporting tissues with aging, especially after menopause, also plays an important role in the initiation or worsening of pelvic relaxation. Iatrogenic factors include failure to adequately correct all pelvic support defects at the time of pelvic surgery, such as hysterectomy.

Diagnosis

Vaginal examination is facilitated by using a single-blade speculum. While the posterior vaginal wall is being depressed, the patient is asked to strain down. This demonstrates the descent of the anterior vaginal wall consistent with prolapse and urethral displacement. Similarly, retraction of the anterior vaginal wall during straining will accentuate posterior vaginal defects and uncover an enterocele and rectocele if present. Rectal and vaginal examinations are often useful to demonstrate a rectocele and to distinguish it from an enterocele.

Quantifying and Staging Pelvic Organ Prolapse

The preferred method for describing and documenting the severity of POP is the Pelvic Organ Prolapse Quantification (POP-Q) system. The extent of prolapse is evaluated and measured relative to the hymen, which is a fixed anatomic landmark. The anatomic positions of the six defined points for measurement are denoted in centimeters above the hymen (negative number) or centimeters below the hymen (positive number). The plane at the level of the hymen is defined as zero ( Figure 23-3 ).

Stages of POP can be assigned according to the most severe portion of the prolapse after the full extent of the protrusion has been determined. An ordinal system is used for measurements of different points along the vaginal canal, which allows for better communication between clinicians. This staging system enables more objective tracking of surgical outcomes.

Management

Prophylactic measures to mitigate the symptoms of POP include identifying and treating chronic respiratory and metabolic disorders, correction of constipation and intraabdominal disorders that may cause repetitive increases in intraabdominal pressure, and, for menopausal women, administration of estrogen. Failure to recognize and treat significant support defects at the time of concomitant gynecologic surgery may lead to progression of existing prolapse and the development of urinary incontinence or retention and urinary tract infections (UTIs).

Nonsurgical Treatment

When only a mild degree of pelvic relaxation is present, pelvic floor muscle exercises may improve the tone of the pelvic floor musculature. Pessaries ( Figure 23-4 ), which provide intravaginal support, may be used to correct prolapse by internally supporting the vagina. They can be considered when the patient is medically unfit or refuses surgery or during pregnancy and the postpartum period. They are also useful to promote healing of a decubitus ulcer before surgery. In many patients, pessaries are the treatment of choice, as they are almost risk-free, immediately available, and useful for interim treatment in those wishing to delay surgery.

Pessaries require proper fitting and must be selected in the appropriate type and size. They should be removed, cleaned, and reinserted every 6 to 12 weeks. They may cause vaginal irritation and ulceration. Neglect may result in serious consequences, including fistula formation, impaction, bleeding, and infection. Many patients are capable of caring for their pessaries themselves. In those cases, the patient inserts, removes, and cleans her pessary several times each week, if not daily. It is similar to the care and use of a contraceptive diaphragm.

Anatomy and Physiology of the Lower Urinary Tract

In the adult woman, the urethra is a muscular tube, 3 to 4 cm in length, lined proximally with transitional epithelium and distally with stratified squamous epithelium. It is surrounded mainly by smooth muscle. The striated muscular urethral sphincter, which surrounds the distal two-thirds of the urethra, contributes about 50% of the total urethral resistance and serves as a secondary defense against incontinence. It is also responsible for the interruption of urinary flow at the end of micturition.

The two posterior pubourethral ligaments provide a strong suspensory mechanism for the urethra and serve to hold it forward and in close proximity to the pubis under conditions of stress. They extend from the lower part of the pubic bone to the urethra at the junction of its middle and distal thirds.

Innervation

The lower urinary tract is under the control of both parasympathetic and sympathetic nerves. The parasympathetic fibers originate in the sacral spinal cord segments S2 through S4. Stimulation of the pelvic parasympathetic nerves and administration of cholinergic drugs cause the detrusor muscle to contract. Anticholinergic drugs reduce vesical pressure and increase bladder capacity.

The sympathetic fibers originate from thoracolumbar segments (T10-L2) of the spinal cord. The sympathetic system has α- and β-adrenergic components. The β-fibers terminate primarily in the detrusor muscle, whereas the α-fibers terminate primarily in the urethra. α-Adrenergic stimulation contracts the bladder neck and the urethra and relaxes the detrusor muscle. β-Adrenergic stimulation relaxes the urethra and the detrusor muscle. The pudendal nerve (S2-S4) provides motor innervation to the striated urethral sphincter.

Factors Influencing Bladder Behavior