Physical Address
304 North Cardinal St.
Dorchester Center, MA 02124
Surgical treatment of anterior vaginal wall prolapse
Introduction
Anterior vaginal prolapse occurs commonly and may coexist with disorders of micturition. Mild anterior vaginal prolapse often occurs in parous women, but usually presents few problems. As the prolapse progresses, symptoms may develop and worsen, and treatment becomes indicated. The anterior vaginal wall is the most common segment of the vagina to prolapse and the segment that is most likely to fail long-term after surgical correction. Over 80% of the more than 300,000 vaginal prolapse surgeries performed annually in the United States include correction of anterior compartment prolapse. This chapter reviews the anatomy and pathology of anterior vaginal prolapse, with and without stress urinary incontinence, and describes methods of surgical repair.
Anatomy and pathology
Anterior vaginal prolapse (cystocele) is defined as pathologic descent of the anterior vaginal wall and overlying bladder base. According to the International Continence Society standardized terminology for prolapse grading ( ), the term anterior vaginal prolapse is preferred over cystocele. This is because information obtained during the physical examination does not allow the exact identification of structures behind the anterior vaginal wall, although it usually is, in fact, the bladder. The Pelvic Organ Prolapse Quantification (POPQ) system for grading and describing prolapse is discussed in detail in Chapter 8 .
The etiology of anterior vaginal prolapse is not completely understood, but it is probably multifactorial, with different factors implicated in prolapse in individual patients. Although age is the most significant factor, other factors include pregnancy, childbirth, connective tissue defects, pelvic floor muscle weakness from denervation or avulsion, hysterectomy, and conditions such as chronic cough or straining associated with elevated intraabdominal pressure (see Chapter 5 ). Normal support for the vagina and adjacent pelvic organs is provided by the interaction of the pelvic muscles and connective tissue. The upper vagina rests on the levator plate and is stabilized by superior (level 1) and lateral (level 2) connective tissue attachments. The midvagina is attached to the arcus tendineus fasciae pelvis ([ATFP], “white lines”) on each side (level 2 attachments), and the apical portion of the anterior vagina is attached to the web of endopelvic fascia, including pubocervical fascia, and the cardinal and uterosacral ligaments. Pathologic loss of lateral and/or apical support (levels 1 and 2) may occur with damage to or impairment of the pelvic muscles, connective tissue attachments, or both, leading to anterior vaginal prolapse.
described two types of anterior vaginal prolapse: distension and displacement. Distension was thought to result from overstretching and attenuation of the anterior vaginal wall, caused by overdistension of the vagina associated with vaginal delivery or atrophic changes associated with aging and menopause. The distinguishing physical feature of this type was described as diminished or absent rugal folds of the anterior vaginal epithelium caused by thinning or loss of midline vaginal fascia. The other type of anterior vaginal prolapse—displacement—was attributed to pathologic detachment or elongation of the anterolateral vaginal supports to the ATFP. This may occur unilaterally or bilaterally, and often coexists with some degree of distension cystocele, with urethral hypermobility, or with apical prolapse. Rugal folds may or may not be preserved.
Another theory ascribes most cases of anterior vaginal prolapse to disruption or detachment of the lateral connective tissue attachments at the ATFP, resulting in a paravaginal defect and corresponding to the displacement type discussed earlier. This was first described by White in 1909 and 1912 but was disregarded until reported by Richardson in 1976. described transverse defects, midline defects, and defects involving isolated loss of integrity of pubourethral ligaments. Transverse defects were said to occur when the “pubocervical” fascia separated from its insertion around the cervix, whereas midline defects represented an anteroposterior separation of the fascia between the bladder and vagina. A contemporary conceptual representation of vaginal and paravaginal defects is shown in Fig. 19.1 .
Improvements in pelvic imaging are leading to a greater understanding of normal pelvic anatomy and the structural and functional abnormalities associated with prolapse. Magnetic resonance imaging (MRI) holds great promise, with its excellent ability to differentiate soft tissues and its capacity for multiplanar imaging. The pelvic organs, pelvic muscles, and connective tissues can be identified easily with MRI. Various measurements can be made that may be associated with anterior vaginal prolapse or urinary incontinence, such as the urethrovesical angle, the descent of the bladder base, the quality of the levator muscles, and the relationship between the vagina and its lateral and apical connective tissue attachments. used an endoluminal surface coil placed in the vagina to image pelvic anatomy with MRI and compared four continent nulliparous women with four incontinent women with anterior vaginal prolapse. Lateral vaginal attachments were identified in all continent women. In Fig. 19.2 the “posterior pubourethral ligaments” (bilateral attachment of the ATFP to the posterior aspect of the pubic symphyses) are clearly seen. In the two subjects with clinically apparent paravaginal defects, lateral detachments were evident ( Fig. 19.3 ). More recent studies based on MRI analysis and computer modeling suggest that apical support abnormalities are at least as important as, if not more important than, paravaginal defects; the degree of apical decent can explain about half of anterior wall descent ( ). Similarly, the size of the genital hiatus (level 3 support) appears important for anterior prolapse recurrence after surgical repair. Other factors, such as levator muscle impairment, levator avulsion, greater anterior wall length, and widened levator hiatus, also contribute to anterior vaginal prolapse. The mean length of the anterior vagina is approximately 6 cm. Women with anterior vaginal wall prolapse have, on average, a 23% longer anterior vaginal wall than women without prolapse, suggesting that anterior vaginal lengthening is one component of the pathophysiology of anterior prolapse.
Anterior vaginal prolapse commonly coexists with urodynamic stress incontinence. Some features of pathophysiology may overlap, such as loss of anterior vaginal support with bladder-base descent and urethral hypermobility; other features, such as sphincteric dysfunction, may occur independent of vaginal and urethral support. The pathophysiology of stress incontinence is covered more fully in Chapter 5 .
Evaluation
History
When evaluating women with pelvic organ prolapse or urinary or fecal incontinence, attention should be paid to all aspects of pelvic organ support. The reconstructive surgeon must determine the specific sites of damage for each patient, with the ultimate goal of restoring both anatomy and function.
Patients with anterior vaginal prolapse complain of symptoms related directly to vaginal protrusion, or associated symptoms such as urinary incontinence or voiding difficulty. Symptoms related to prolapse may include the sensation of a vaginal mass or bulge, pelvic pressure, low back pain, and sexual difficulty. Stress urinary incontinence commonly occurs in association with anterior vaginal prolapse, particularly when it is mild. In contrast, women with anterior vaginal prolapse that extends beyond the hymen are less likely to complain of stress incontinence and are more likely to have obstructed voiding symptoms such as urinary hesitancy, intermittent flow, weak or prolonged stream, a feeling of incomplete emptying, the need to reduce (splint) the prolapse manually to initiate or complete urination, and, in rare cases, urinary retention. The mechanism for this appears to be mechanical obstruction resulting from urethral kinking that occurs with progressively worsening anterior vaginal prolapse.
Physical examination
The physical examination should be conducted with the patient in the lithotomy position, as for a routine pelvic examination. The examination is first performed with the patient supine. If physical findings do not correspond to symptoms, or if the maximum extent of the prolapse cannot be confirmed, the woman is reexamined in the standing position.
The genitalia are inspected, and, 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 approximate size of all prolapsed parts is assessed. A retractor or vaginal speculum can be used to depress the posterior vagina to aid in visualizing the anterior vagina. After the resting examination, the patient is instructed to strain down forcefully 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 straining.
It may be possible to differentiate lateral defects, identified as detachment or effacement of the lateral vaginal sulci, from central defects, seen as midline protrusion but with preservation of the lateral sulci, by using a curved forceps placed in the anterolateral vaginal sulci directed toward the ischial spines. Bulging of the anterior vaginal wall in the midline between the forceps blades implies a midline defect; blunting or descent of the vaginal fornices on either side with straining suggest lateral paravaginal defects. Studies have shown that the physical examination technique to detect paravaginal defects is not particularly reliable or accurate. In a study by of 117 women with prolapse, the sensitivity of clinical examination to detect paravaginal defects was good (92%), yet the specificity was poor (52%), and, despite an unexpectedly high prevalence of paravaginal defects, the positive predictive value was poor (61%). Less than two-thirds of women believed to have a paravaginal defect on physical examination were confirmed to have the same at surgery. Another study by demonstrated poor reproducibility of clinical examination in detecting specific anterior vaginal wall defects. Thus, the clinical value of determining the location of midline, apical, and lateral paravaginal defects remains unknown.
Anterior vaginal wall descent usually represents bladder descent with or without concomitant urethral hypermobility. In 1.6% of women with anterior vaginal prolapse, an anterior enterocele mimics a cystocele on physical examination ( ). Other uncommon conditions, such as anterior vaginal cysts or myomas, can also mimic anterior vaginal prolapse.
You're Reading a Preview
Become a Clinical Tree membership for Full access and enjoy Unlimited articles
If you are a member. Log in here