Dee E. Fenner
Urinary incontinence is a medical condition affecting 15% to 50% of adult women depending on the age and risk factors of the population studied. As we live longer and enjoy more active lives, increasing numbers of women will be affected. Costing approximately $12.4 billion dollars to treat women alone in 1995, urinary incontinence ranks in the top ten in expenditures for treatment of illnesses.
While once considered a “natural” consequence of aging, further investigations have shown that urinary incontinence is seen in women of all ages, with varying degrees of severity and different etiologies. Unfortunately, incontinence often goes undetected and only half of the women suffering from this condition seek treatment. This is unfortunate because there are many types of effective therapies available including bladder retraining, pelvic floor exercises, and surgery.
As health care providers for women, we are obligated to ask the question “Do you have difficulty controlling your bladder?” Once the condition is identified, specific questions targeted at identifying the type of incontinence, the frequency of loss, and the social impact for the woman can be addressed. Many times with the use of voiding diaries, detailed physical examinations, and simple bladder testing, the cause of incontinence can be determined and treated.
DEFINITIONS OF TERMS AND DIFFERENTIAL DIAGNOSIS OF URINARY INCONTINENCE
Maintenance of urinary incontinence requires that many anatomic, neurologic, and psychological functions and relationships be intact. Therefore, it is not surprising that many conditions may affect urinary continence (Table 48.1, Table 48.2).
|
|
|
TABLE 48.1. Drug effects on lower urinary tract function |
|
|
|
TABLE 48.2. Causes of urinary incontinence |
In order to communicate with the patient and other practitioners that evaluate, diagnose, and treat the various causes of urinary incontinence, a standardization of terms and description of conditions is required. A committee on terminology as part of the International Continence Society (ICS) has provided standardized terms and definitions for the classifications of functions of the lower urinary tract. The ICS definitions of terms and conditions of urinary incontinence are listed in Table 48.2 and Table 48.3.
|
|
|
TABLE 48.3. International Continence Society terms and definitions |
Patients with symptoms of urinary incontinence are generally not concerned about the strict definition of their condition but are rightly focused on the cause and foremost the treatment of their incontinence. As clinicians, we may or may not agree with the patient on the severity of her symptoms. Generally, when the symptoms are mild, the patient and practitioner are nearer in agreement than when the patient perceives her symptoms as severe. Therefore, it is useful to use standardized criteria or a validated quality-of-life measure to determine the impact of the incontinence condition on the patient's ability to perform her daily activities. Several such questionnaires exist and can be beneficial in the initial assessment as well as determining the benefit of therapy. An example of such a validated questionnaire is seen in Table 48.4.
|
|
|
TABLE 48.4. Urogenital distress inventory (UDI-6) |
A patient complaining of stress symptoms may actually have cough-induced detrusor overactivity or mixed incontinence. Therefore the clinician must not only listen to the symptoms of the patient, but also document some sign of urinary incontinence. Signs of urinary incontinence are objective measures of urine loss evaluated in conjunction with the bladder state (empty or full) and conditions of leakage. Signs include urine loss documented by a voiding diary noting physical activity or bladder urgency linked to incontinence, a pad test, a cough stress test, or urine leakage at the time of urodynamic testing.
EPIDEMIOLOGY
Prevalence and Social Impact
Urinary incontinence is a common problem among women. The estimated prevalence ranges from 3% to 40% depending on the population studied and how the condition is defined. Approximately 10% to 30% of community-dwelling women between the ages of 15 and 64 years of age and 25% of women older than 65 years experience urinary incontinence. Approximately 50% of nursing home patients have urinary incontinence. One in five women with urinary incontinence will also suffer from fecal incontinence or “dual incontinence.” Urinary incontinence is two to three times more likely in women than in men. This is especially true for women under the age of 60, when stress incontinence is more likely the dominant type. As men and women age, the likelihood of urge incontinence or voiding dysfunction increases in both sexes.
How urinary incontinence is defined determines the prevalence of the condition in the population or the incidence of the condition at any given time. Clinicians generally use the ICS definition of urinary incontinence that is “the involuntary loss of urine sufficient to be a social or hygienic problem for the patient.” For some women this may mean leaking urine once a day, while for others urinary incontinence occurring only periodically with exercise may be unacceptable. Survey studies of community-dwelling women using “daily,” “weekly,” or “most of the time” criteria for diagnosing urinary incontinence report prevalence ranges of 3% to 14%. This amount of leakage corresponds with the frequency of leakage found in women seeking treatment. Higher estimates of incontinence are based on broader definitions, such as “any incontinence in the prior year” or “leakage more than twice a month.”
Many etiologies and factors contribute to urinary incontinence and many of the factors are variable over time and affect the presence and severity of urine loss. The strength of the pelvic floor muscles and urethral sphincter, the level of physical activity or high-impact exercise, the amount of fluid intake, or the level of bacteria are just of few of the variables that relate to urinary incontinence. While little information is known about the natural progression of incontinence severity, for women surveyed over a 2-year span, there was an 11% remission rate or resumption of continence.
Risk Factors
Many risks factors, conditions, or causes have been linked to the development of urinary incontinence. Unfortunately, few longitudinal and well-designed studies have been performed to separate the cause and effect for many of the risk factors. Why certain conditions and events such as childbirth and aging affect some women and not others is still unknown. Bump has developed a model (Fig. 48.1) combining many of the known risk factors for the development of urinary incontinence. Which of these factors are most important and how they interact for a particular patient is not known but are areas of current investigation.
|
|
|
FIG. 48.1. Factors related to the development of urinary incontinence. (From Bump RC, Norton PA. Epidemiology and natural history of pelvic floor dysfunction. Obstet Gynecol Clin North Am 1998;25:723.) |
Gender and Age
Urinary incontinence is two to three times more likely to occur in women than in men. This is especially true regarding community-dwelling adults under 60 years of age. Compared to urge incontinence, stress incontinence is more common in younger women and rarely occurs in men. Since childbirth is considered a major risk factor for the development of stress urinary incontinence, it is not surprising that this condition occurs more often in women than in men. But as men and women age, they both have more symptoms of bladder overactivity, urge incontinence, and voiding dysfunction. These symptoms develop such that the gender gap narrows as men and women approach the age of 70.
Brown and colleagues have shown that 12.5% of women under 80 years of age reported daily incontinence and that for every 5-year increment in age beginning at age 80, there was a 30% increase in the prevalence of incontinence. While increasing age is consistently seen as a risk factor for urinary incontinence, the idea that urinary incontinence is a “natural” part of aging is not true. Like other conditions, such as heart disease, hypertension, and arthritis, incontinence is more prevalent as we get older. Like these other conditions, not all older people suffer from incontinence and those who do should be offered treatment and care and not left to “suffer this malady of old age.”
Why urinary incontinence increases with age is not fully understood. With aging, approximately 1% of striated muscle mass is lost each year. Since the sphincter urethra muscle, as well as pelvic floor muscles play important roles in the maintenance of incontinence, it is not surprising that incontinence increases with aging. How aging, menopause, and decreasing hormone levels relate to urinary incontinence and other pelvic floor dysfunctions is poorly understood. Studies evaluating the use of oral combined estrogen replacement therapy have not shown improvement in or prevention of the development of urinary incontinence. Yet clinicians and some patients note improvement in function of the lower urinary tract, especially in decreasing nocturia, when using transvaginal estrogen replacement therapy. Further studies on the effect of estrogen on the blood supply, smooth muscle of the urethra and vaginal submucosa, and collagen content of the anterior vaginal wall are needed to determine the usefulness, correct route and preparation, and dosage of hormone replacement therapy that could be beneficial.
Race
Racial differences in the prevalence and type of urinary incontinence have been reported but remain poorly understood. Fultz and associates reported a urinary incontinence prevalence of 23% in Caucasian women and 16% in African-American women in a national survey of 4,040 community-dwelling individuals over the age of 70. Smaller studies evaluating younger women do not include large enough numbers of African-American, Hispanic, or Asian women to make any conclusions about the prevalence or type of incontinence. In women seeking treatment for incontinence, African-American women appear to have more urge incontinence and detrusor overactivity on urodynamic testing than pure stress incontinence. Whether these differences are related to treatment patterns or true biologic differences is yet undetermined. It does appear, however, that there are racial differences in urethral muscle mass, urethral closure pressures, and urethral hypermobility between continent nulliparous African-American women and Caucasian women. These findings suggest morphologic and physiologic reasons for racial differences in the type of urinary incontinence.
Childbirth
Vaginal childbirth has been seen as the leading inciting factor in the development of urinary incontinence and pelvic floor dysfunction. Yet vaginal delivery does not lead to urinary incontinence in all women and women who have never delivered vaginally or have even been pregnant can develop urinary incontinence and pelvic floor dysfunction. Strong associations have been made between vaginal delivery and stress urinary incontinence. Large population studies have also shown vaginal childbirth is also a risk factor for developing urge incontinence.
Women who deliver by elective cesarean section without ever laboring have a reduced risk of developing urinary incontinence compared to women who deliver vaginally, but a cesarean section is not 100% protective. In addition, the protective benefits appear to decrease after three pregnancies and repeat cesarean sections. Episiotomies, once thought to be protective, have not been shown to decrease or increase the risk of urinary incontinence, either immediately after birth or after several years.
The majority of the damage to the pelvic tissues appears to occur with the first delivery. Other factors associated with increased risk from vaginal delivery include forceps deliveries, prolonged second stage, large-for-gestational-age birth weight, and large head circumferences. Not all of these obstetric factors have been found to be statistically or clinically significant in the literature and their etiologic role in the development of urinary incontinence remains to be determined.
Vaginal childbirth causes damage to the pelvic floor tissues by stretching, tearing, and pressing the soft tissues against the bony pelvis causing anoxia and tissue necrosis. The muscles, nerves, and connective tissues of the pelvis can all be affected and damaged. Studies have shown damage to all of the tissues as measured by prolonged pudendal nerve motor latencies, decreased levator muscle strength, and decreased urethral pressures. Fortunately, with healing and muscle strengthening with Kegel exercises, the majority of the damage can be repaired, and continence regained in the first 6 months after delivery. Long-term pelvic floor trauma secondary to vaginal delivery and aging appear to combine as the major risk factors for urinary incontinence and pelvic floor dysfunction.
Smoking, Exercise, and Obesity
Women who are cigarette smokers or ex-smokers are two to three times more likely to have urinary incontinence than nonsmokers. Whether this association is related to chronic cough and increased abdominal pressure or tissue damage from tobacco toxins is not known.
Physiologically, exercise has many positive and negative effects that may alter the balance between continence and incontinence. Increased abdominal pressure with high-impact exercise may overcome the continence mechanism in some women briefly causing situational episodes of leakage, but does not appear to increase their long-term risks for developing stress incontinence. Exercise that strengthens the lower extremities also strengthens the pelvic floor and enhances the continence mechanism. For the many health benefits, including strengthening the pelvic floor, women should be encouraged to exercise or take daily walks.
Obesity has been shown to be more common in women with both stress and urge incontinence than in continent women. In addition, morbidly obese women who lose weight have shown objective as well as subjective cure of their incontinence. Consideration should be given to surgically managing their morbid obesity over surgically attempting to correct their stress incontinence.
EVALUATION OF URINARY INCONTINENCE
History
The first step in evaluating a patient with urinary incontinence is to pose the question to the patient. Often a brief, directed review of bladder and bowel function can elicit symptoms. Open-ended questions such as “Could you please tell me about problems you are having controlling your bladder?” can be a useful initial approach. If the answer is affirmative for incontinence symptoms then an incontinence evaluation in initiated.
The evaluation begins with more direct questioning concerning the patient's symptoms, timing, and severity of incontinence. Frequently asked questions listed in Table 48.5 can help distinguish the type and severity of a patient's incontinence. Questions aimed at type of protection or pad used and number of pads used in a 24-hour period can indicate the severity of the problem. In addition, questions regarding lifestyle changes such as decreasing fluid intake or avoiding physical activities reflect the impact of incontinence on the patient's quality of life.
|
|
|
TABLE 48.5. Frequently asked questions |
The presence of symptoms associated with both the storage and the emptying phases of the bladder cycle should be determined. Specific questions should ask about irritative symptoms (urgency or frequency), incontinence (stress or urge), and voiding dysfunction (urinary retention or postvoid fullness). A detailed history of any prior treatment of the genital or urinary tract, including surgeries should be obtained. The surgical history should contain details of any prior procedures for incontinence, including indications, technique, and type of suture used. Any complications (i.e., prolonged catheter use after surgery) or the development of new symptoms (i.e., urinary frequency and urgency following surgery) should be noted.
An obstetric history including route of delivery, episiotomy, lacerations, the use of forceps or vacuum, birth weights, and the length of the second stage of labor can determine the patient's risks associated with childbirth. A history of pelvic cancer therapy should include the dates and findings of any cystoscopic examinations. Other comorbid conditions affecting the lower urinary tract, including cigarette smoking, neurologic and endocrine diseases, as well as family history of urinary incontinence and pelvic organ prolapse may direct the clinician toward one type of urinary incontinence or need for further diagnostic evaluation. Any functional components such as difficult ambulation, declining cognition, or severe fecal impaction or constipation should be addressed prior to further evaluation or treatment.
Medications currently used should be reviewed in detail as many medications have adverse effects on the lower urinary tract (see Table 48.1). Unfamiliar medications should be verified. Diuretics and α-antagonists, two classes of medication commonly used to treat hypertension, may cause incontinence in some women. When incontinence is temporarily related to onset of use or dosage increase, it may be reasonable to use alternative medications that have less effect on the lower urinary tract.
Office evaluation should follow a stepwise progression (Fig. 48.2). Initial evaluation should focus on the severity of urinary leakage and the patient's goals for resolution of the problem. Some women may simply wish to regain sufficient bladder control to participate in certain social or athletic activities, while others desire complete continence under all circumstances. The extent of the evaluation and the proposed therapy should match the patient or her caregiver's expectations and goals.
|
|
|
FIG. 48.2. Evaluation algorithm. (From Fantyl JA, Newman DK, Colling J, et al. Urinary incontinence in adults: acute and chronic management. Clinical Practice Guidelines Number 2, 1996 Update. Rockville, MD: Agency for Health Care Policy and Research, US Dept of Health and Human Services; 1996. AHCPR publication 96-0682.) |
Physical Examination
Beyond the standard speculum and bimanual examination, the specific goal of a urogynecologic physical examination is to assess vaginal supports, strength of the pelvic floor, the anatomic position of the anterior vaginal wall, and the stability of the urethrovesical junction (UVJ). The examination for pelvic organ prolapse and the use of the standardized Pelvic Organ Prolapse Quantitative System (POP-Q) can be found in Chapter 45. In addition to noting any prolapse of the vaginal walls, uterus, or vaginal apex, the resting location and mobility of the UVJ with cough or strain is noted. In most cases, the urethral hypermobility can be documented by having the patient strain and the clinician noting prolapse of the distal anterior vaginal wall. If uncertain, and deemed important by the clinician, then a sterile Q-tip may be placed in the urethra or transperineal ultrasound used to document mobility. Not all women with a hypermobile urethra have stress incontinence and not all women with stress incontinence have a hypermobile urethra. African-American women appear to have more urethral hypermobility than Caucasian women, yet they have less stress incontinence because of higher urethral pressures. The importance of noting a hypermobile urethra is useful when considering certain treatment options. Both surgical and nonsurgical techniques that work by stabilizing or supporting the UVJ work best when the urethra is hypermobile allowing for repositioning or stabilization.
Neurologic evaluation of the incontinent female includes assessing intact perineal sensation that primarily represents the S2 dermatome. The bulbocavernosus reflex or anal wink is used to assess the sacral reflexes. A Q-tip swab is gently used to touch the skin overlying the bulbocavernosus muscles in the labia majora or perianally. A positive reflex indicates an intact pudendal nerve and L5-S5 motor neurons causing spontaneous contraction of the external anal sphincter. As with other reflexes, the sign is positive or negative. Hyperreflexia may be seen in upper motor lesions. Unlike the corresponding cremaster reflex in men, approximately 10% of normal, neurologically intact women will not demonstrate this reflex or the response is too weak to see. If, however, in the context of urinary or fecal incontinence or with other neuromuscular abnormalities of the buttocks or lower extremities, the absence of the bulbocavernosus reflex should alert the clinician to possible pathology in the sacral or cauda equina regions of the spinal cord.
A cough stress test should be performed, noting the position of the patient as supine or standing and whether her bladder is full or empty. Documentation of the sign of stress incontinence is adequate for diagnosis in most patients and avoids performing further, more complex and expensive testing.
Other conditions that can be detected during physical exam include hypoestrogenism, levator atrophy, and fecal impaction, which can all affect bladder control. If comorbid conditions such as edema or declining cognitive function are contributing to the patient's incontinence, then an expanded physical examination including mental status assessment, manual dexterity, and ability to ambulate is warranted.
Urinary Diary or Bladder Record
While not always available at the time of the initial history and physical, the urinary diary is an essential part of the of incontinence evaluation (Fig. 48.3). This tool allows the patient to record voided volumes, leakage episodes including amounts and associated activities, and the type and volume of fluid intake. Although a 3- to 7-day diary is optimal, evaluation of the events of a typical 24-hour period can be very helpful clinically. By simply keeping the diary, patients can notice how the amount and types of fluid they drink, as well as when they drink impact incontinence. In addition, the clinician can assess the severity of the leakage and begin to formulate an opinion of the type and etiology of the patient's incontinence and need for further evaluation. Upon review of the diary, the practitioner can suggest simple behavioral interventions such as fluid intake and medication adjustments.
|
|
|
FIG. 48.3. Voiding diary. |
Urinalysis and Postvoid Residual Volume
Sterile urine and a normal postvoid residual volume should be documented in all women. This assessment can be performed using a small-gauge catheter within 20 minutes after voiding. While there is no strict definition of a normal postvoid residual, the volume should generally be less than 100 mL. The catheterized urine specimen can then be used to rule out infection. While dipstick methods are available to detect bacteriuria and pyuria, the diagnostic accuracy is variable and dependent on the prevalence of urinary tract infections in that population. Therefore if the dipstick is positive or the patient's symptoms are consistent with a urinary tract infection, obtaining a urine culture is recommended.
Alternatively, an approximation of postvoid residual volume may be obtained with the use of an ultrasound specifically designed for determining bladder volume and using a clean catch urine sample to rule out infection. Infection should be treated and sterile urine should be demonstrated before further incontinence evaluation. If the residual volume is elevated, the test should be repeated on a separate visit. Persistently high residual volume should be evaluated. Conditions affecting bladder emptying such as peripheral neuropathies or pelvic organ prolapse outside the hymen are common etiologies for elevated postvoid residuals. Unlike men who frequently suffer urinary retention due to obstruction by an enlarged prostate gland, women rarely have obstruction unless they have undergone prior surgery for urinary incontinence that is obstructing urine flow.
Stress Test
The stress test is used to observe urinary leakage associated with straining or coughing, and is best performed with a full bladder in the standing position. Often a series of coughs is required to demonstrate incontinence. The patient should be positioned over a pad or paper towel, wrapped with a sheet or gown, and reassured that the physician wants to see urine leakage. Many times patients are embarrassed and reluctant to leak urine in the office setting in front of other people. Putting the patient at ease and respecting her privacy helps to obtain a positive test and preserves patient dignity. A positive test confirms the sign of stress incontinence. A negative test does not completely rule out stress incontinence, but when performed with a full bladder and in the standing position the diagnosis of stress incontinence is less likely. If the patient also suffers from pelvic organ prolapse, then the prolapse should be repositioned to a “normal” anatomic position with a pessary or large vaginal swabs during the stress test.
Pad Test
A pad test is an objective test used to document the presence and amount of urinary incontinence. The test requires that the patient wear a preweighed pad while she performs activities usually associated with her incontinence. A 1-hour pad test is typically conducted. Generally, the test begins with the patient emptying her bladder and then drinking a known amount of water, typically 500 cc. Alternatively, the bladder can be filled with a set amount or to maximum capacity. The pad is weighed after 1 hour of activity. While pad testing has been found to be reproducible, in terms of objective documentation of incontinence and ability to evaluate pre- and post-treatment incontinence, its use in routine clinical evaluation is limited. A specific use for the pad test is when the clinician is unsure if the symptoms of incontinence are due to urine loss or secondary to vaginal secretions or sweating. By giving the patient phenazopyridine hydrochloride (Pyridium) to turn her urine orange, a pad test can confirm urine loss.
After taking a careful history, performing a directed pelvic examination including a postvoid residual, ruling out infection, and performing a stress test, an accurate diagnosis can be made on the type of urinary incontinence for approximately 80% of women. Initial management can begin as outlined in Table 48.6.
|
|
|
TABLE 48.6. Management options after basic evaluation |
Specialized Tests
The need and use of specialized tests for the diagnosis and management of patients with urinary incontinence is far from standardized in clinical practice. While some clinicians feel advanced testing is useful, the reproducibility of certain tests such as multichannel urodynamics, leak point pressures, and voiding studies have led many clinicians and expert panels to use specialized testing in selected cases. The Agency of Health Care Policy and Research under the jurisdiction of the United States Department of Health and Human Services has recommended the use of specialized testing according to the guidelines listed in Table 48.7. Clinicians caring for patients with urinary incontinence recognize the difficulties in trying to determine the exact cause of leakage in all patients. When therapies can be used which effectively treat both urge and stress incontinence or there is acceptable cost and morbidity for the individual patient, determining the exact etiology is less critical. However, prior to surgical interventions, because of cost and morbidity, cystometry is recommended to document stress incontinence.
|
|
|
TABLE 48.7. Criteria for Further Evaluation of Urinary Incontinencea |
If a patient presents with moderate to severe pelvic organ prolapse outside the hymen and has no subjective urinary incontinence, she should be tested for occult or potential stress incontinence. Studies have shown that with the prolapse reduced and straightening of the urethra, incontinence can “occur” in 30% to 50% of patients with prolapse. If urinary incontinence is found, then an antiincontinence surgery should be performed at the time of surgical correction for the patient's pelvic organ prolapse. Which antiincontinence surgery is best for occult incontinence is not known.
Consultation should be considered for cystometric testing and surgical management for patients who have not responded to initial treatments or have failed prior incontinence procedures.
Cystometry
Cystometry is the test used to measure the pressure–volume relationship during bladder filling. The main purpose of cystometry is to diagnose or rule out detrusor contractions. A catheter attached to a vertical fluid column, a pressure transducer, or a microtip catheter measures the bladder pressure. Single channel or simple cystometry implies that only the bladder pressure is being monitored during the study. A multichannel or complex cystometry includes a second catheter for monitoring intraabdominal pressure. During a multichannel study, true detrusor pressures are calculated by subtracting the intraabdominal pressure from the bladder pressure. While filling the bladder, the compliance (bladder pressure divided by the infused volume), the first desire to void, maximum bladder capacity, and the presence of detrusor contractions are documented. Stress incontinence is diagnosed with the patient coughing or by performing a Valsalva maneuver and noting urine loss in the absence of a detrusor contraction.
Simple Cystometry or Single Channel Cystometry
Performing simple cystometry can easily be done in the office of most gynecologists using a red rubber catheter, a three-way stopcock, intravenous tubing, and sterile water or saline. The patient is placed supine or if possible seated at a 45-degree angle. The sterile catheter is inserted and a postvoid residual volume is obtained. By attaching a three-way stopcock to the end of the catheter, a tube for filling and a tube for measuring detrusor pressures can be used. By taping the pressure tubing vertically to a 100-cm measuring stick taped to an intravenous pole, and then having the zero mark at the level of the bladder, the bladder is filled in 50- to 100-cc increments. After filling, the stopcock is turned off to the filling catheter. The pressure in the tubing represents the pressure in the bladder, including the intraabdominal pressure. The patient is instructed not to talk or perform any maneuvers that will increase her intraabdominal pressure. A rise in the fluid column should then represent a rise in bladder pressure secondary to abnormal compliance or a bladder contraction (Fig. 48.4).
|
|
|
FIG. 48.4. Simple office cystometrogram. The zero mark of a meter stick is aligned with the upper margin of the patient's symphysis pubis, and a Foley catheter is in place for infusion of fluid. (Adapted from the American College of Obstetricians and Gynecologists, Bent AE, ed. Urogynecologic evaluation, endoscopy, and urodynamic testing in the symptomatic female. Washington, DC: ACOG Audiovisual Library, 1990.) |
An alternative method for simple cystometry uses a specialized filling catheter with a pressure transducer that relays the bladder pressure to a recording device. Several types are commercially available.
Multichannel Urodynamics
Approximately 10% of patients require multichannel urodynamic studies for diagnosis and treatment of urinary incontinence. Like all diagnostic tests, the clinician must understand the information gained from the procedure, the accuracy of the measurements, and how the information obtained will alter diagnosis, prognosis, or management of the condition. Multichannel urodynamics, once considered the gold standard for the diagnosis of detrusor overactivity and stress incontinence, have been questioned regarding their reproducibility and cost-effectiveness in the routine evaluation of urinary incontinence. As outlined in Table 48.7, if initial assessment and treatment are not successful, further evaluation with multichannel urodynamic studies is indicated. Table 48.8lists the common terms and definitions for urodynamic studies. Multichannel urodynamics are performed using a specialized machine or unit that records the bladder and intraabdominal pressures, subtracts the intraabdominal pressure from the bladder pressure to determine true detrusor pressure, and provides a report. Most units also have the ability to record urethral pressures and electromyography of the pelvic floor or urethra during the multichannel study. When reporting a multichannel cytometric study, the filling medium, rate of bladder fill, and position of the patient during the study should be noted. A typical tracing for a patient with detrusor overactivity is seen in Fig. 48.5. Note the rise in detrusor pressure without a rise in the abdominal pressure that is seen with a cough.
|
|
|
TABLE 48.8. Cystometric definitions |
|
|
|
FIG. 48.5. Cystometric tracing. |
Uroflow Studies and Voiding Cystogram
Uroflowmetry measures the flow rate visually, electronically, or with the use of a disposable unit and is measured in mL per second. An electronically generated flow curve is considered helpful in identifying abnormal flow patterns such as Valsalva voiding (increasing vesicle pressure by pushing rather than having a detrusor contraction). Uroflowmetry does not help diagnose the type of urinary incontinence and is not a routine part of the evaluation of urinary incontinence. A voiding cystometrogram is a uroflow performed with a catheter in the bladder to record bladder pressures. For a patient with urinary retention, a voiding cystogram may help distinguish obstruction from detrusor weakness. A voiding cystometrogram may be useful in the evaluation of patients with elevated postvoid residuals, neurologic conditions such as diabetes that may affect bladder emptying or inability to void after extensive pelvic surgeries, or antiincontinence procedures.
Urethral Pressure Profilometry
Urethral pressure profilometry (UPP), a urethral function test, measures resting and dynamic (with cough) pressures in the urethra. Clinically, UPP is used by some clinicians to assess the patient for a weak sphincter or intrinsic sphincter deficiency (ISD). Patients with ISD have been found to have less success with antiincontinence surgeries aimed at repositioning or elevation of the bladder neck and therefore the diagnosis of ISD would determine which surgical procedure was used. Sphincteric function can also be assessed by measuring abdominal or vesical pressure needed to overcome urethral resistance or abdominal or vesical leak point pressure. Clinically, the usefulness of the UPP versus abdominal leak point pressure has not been adequately studied.
Electromyography
Both surface and needle electrodes have been used to record urethral sphincter and pelvic floor muscle activity during urodynamic studies. Technically difficult to reproduce, except in a few urodynamic laboratories which have expertise in electromyography (EMG), the clinical usefulness is questionable. The goal of EMG is to evaluate relaxation of the pelvic floor and urethra at the time of voiding. Many patients, while seated in the urodynamics chair with catheters in place and persons in the room, will have difficulty relaxing their pelvic floor and may give a false-positive test for EMG activity and poor relaxation during voiding. Pathologically, patients with detrusor sphincter dyssynergia (DSD) have a detrusor contraction to void but the urethra and periurethral striated muscle contract preventing or decreasing urine flow. DSD is caused by an upper motor neuron injury, most commonly multiple sclerosis.
Cystourethroscopy
Cystourethroscopy is not recommended in the basic evaluation of urinary incontinence. For patients with bladder pain, sterile microscopic or gross hematuria, new-onset irritative symptoms without infection, or suspected intravesical foreign body, a cystoscopy is warranted to rule out neoplasia.
TREATMENT OPTIONS
Three major categories of treatment for urinary incontinence include behavioral, pharmacologic, and surgical. Treatment options are often used in combination, such as behavior modification with timed voiding in conjunction with pelvic floor exercises for strengthening the pelvic floor. Realistic expectations for success and any risks of the therapy must be reviewed with the patient before initiating treatment. In choosing treatment for one condition, the potential for exacerbating another condition must be considered. For example, surgery performed to cure minor stress incontinence may dramatically worsen urge incontinence.
Behavioral Techniques
When taught or provided by knowledgeable health care providers, behavioral techniques decrease the frequency of urinary incontinence in most individuals, have no reported side effects, and do not limit future treatment options. Behavioral therapies are most successful when persons can actively participate in their training program, but they can be provided effectively by caregivers for patients with cognitive and motor deficits.
Bladder Retraining
Behavioral modification is defined as the analysis and alteration of the relationship between the patient's symptoms and her environment for the treatment of maladaptive voiding patterns. Because most women either decrease their fluid intake or urinate more frequently in order to avoid leakage, behavior modification is helpful in virtually every patient with urinary incontinence. By inquiring about self-directed modifications the patient has made in her diet, fluid intake, or activity level, the practitioner can gain insight not only into the patient's diagnosis, but save time and have a more direct impact by not recommending modifications that the patient has already tried.
Simple techniques may be discussed after review of the urinary diary, including adjustments in the type and volume of fluid intake. Older patients frequently have nocturnal diuresis. The diaries of these patients reflect several episodes of nighttime voiding, possibly with urinary loss while en route to the toilet. However, the important diary clue is a large bladder volume—sometimes larger than the patient's first morning voided volume. Rather than adding a nighttime bladder medication, a late afternoon supine rest or leg elevation can help the diuresis.
Consuming large volumes of fluid intake, often in an attempt to aid weight loss, is a problem and should be addressed. Women should be counseled to drink and titrate their fluids according to urine color and number of voids. Generally the urine should be a light yellow. Women should aim for six to seven voids in a 24-hour time period.
Inadequate hydration may be found in women who restrict intake as a method of controlling their incontinence symptoms. For some women, this may contribute to urgency and frequency as the concentrated urine is more irritative to the bladder than dilute urine. Also, caffeinated beverages increase urinary urgency and frequency and may exacerbate incontinence episodes.
Timed voiding is effective for approximately 60% of women with detrusor overactivity. The patient is instructed to void at a specific interval by the clock during waking hours. By examining the voiding diary, a voiding interval that is slightly longer than the current interval that results in leakage is used as a starting time. For example, if a patient is voiding every 30 minutes to avoid leakage, she is encouraged to try and hold her urine for 1 hour and to use the clock to monitor her frequency. Over a period of 6 to 8 weeks, the intervals are gradually lengthened until the patient is able to urinate without leakage at 3- to 4-hour intervals. An alternative technique for women who are going to the bathroom every 30 minutes to 1 hour to avoid incontinence is to add 15 minutes of waiting time to when they feel the first desire to void. By asking the woman to sit and squeeze her pelvic floor when she feels the urge to void and to try and wait 15 minutes before voiding, she can again increase her times between voids to 3- to 4-hour intervals within 6 to 8 weeks. These techniques have significant advantages, including the lack of systemic adverse effects and the minimal cost. It is an ideal initial intervention for many women. Written materials are helpful for optimal understanding and compliance. For women with cognitive impairment or decreased mobility, timed-voiding prompted by a caregiver can also be effective in decreasing the number of incontinent episodes and the amount of leakage. A bedside commode can facilitate voiding and help the patient avoid falls. These behavior modification techniques are often done in conjunction with pelvic floor exercises and have been found to be equal to or more effective than pharmacotherapy for some women with urinary incontinence.
Pelvic Floor Muscle Training
Pelvic floor muscle training is defined as “repetitive selective voluntary contraction and relaxation of specific pelvic floor muscles.” Most women are familiar with the concept of pelvic floor exercises often termed “Kegels” after the gynecologist who first introduced the concept in the 1950s. Women with weakened pelvic floor muscles may benefit from muscle-training protocols. These protocols are helpful for patients with detrusor overactivity or stress incontinence. Muscle rehabilitation aims not only to strengthen but to activate the muscle contraction at the appropriate time. Miller and colleagues have shown that with proper instruction as to the timing of the pelvic floor contraction with a cough or urge to void, women can have immediate success in decreasing their incontinence before any strengthening of the pelvic floor muscles takes place. Like exercises aimed at strengthening other striated muscles, measurable improvements in strength occur after 4 to 6 weeks of training.
Patients frequently have difficulty identifying muscles used in pelvic floor contractions and are unaware if they are contracting the right muscles and how to perform the exercises. Assessment as part of the exam for pelvic floor dysfunction can help the patient isolate the right muscles. The examiner places an index finger with light pressure on the posterior fourchette and asks the patient to Kegel, or squeeze her pelvic floor as if she is trying to hold urine or not pass flatus. Another method is to have the patient try to stop her urine flow. This method should only be used as a test and not for performing the exercises. If the patient is able to stop or slow the urine flow then she is squeezing the correct muscles and a strengthening program can be initiated. Women with profound weakness or apparent paralysis generally require a supervised exercise program and biofeedback or electrical stimulation therapy. Biofeedback uses a pressure balloon, surface electrodes that record pelvic floor muscle activity, or another measuring device that, visually or by sound, alerts the patient that she is squeezing the proper muscles. Over time, the patient is able to isolate and contract the muscles without the auditory or visual cue and a formal exercise program can be initiated.
Strength can be gained through a variety of exercise programs. There is little scientific evidence to suggest the superiority of any specific muscle-training regimen; however, it is likely that general principles of muscle strengthening apply. Physical therapists and nurses may be helpful in initiating and supervising the rehabilitation program. Simple written or verbal instructions may be sufficient to teach patients how to perform pelvic muscle exercises properly.
Performing these exercises supine decreases the gravitational forces and may make the exercise easier for the patient to perform. With improved strength, she may advance to exercising in the upright position. Patients should be instructed to perform 10 to 20 ten-second pelvic floor contractions three or more times per day. A minimum of 30 contractions per day for at least 6 weeks is usually required to achieve a detectable beneficial effect. Too vigorous a program should be discouraged as muscle soreness could result in dyspareunia and abandonment of the exercise program. Older women may need a longer training period. These exercises should be performed indefinitely to prevent recurrence of incontinence.
An adjunct to biofeedback and standard pelvic floor exercises is the use of weighted vaginal cones. The cones, weighted 20 to 100 g, are used as part of a structured, progressive, resistive exercise program. Women insert the plastic coated cone into the vagina much like a tampon, and attempt to keep the cone from falling out by squeezing the pelvic floor. The exercise is performed for 15 to 20 minutes once a day. Once a weight has been successfully held for 3 days, the next higher weight is used. For women with stress incontinence, weighted cones have been found to be equal to other pelvic floor exercise programs where patients are monitored closely by nurses or physical therapists. Cones may be preferred by some women because they are done at home, do not require nursing or physical therapy visits, and they are relatively inexpensive.
Regardless of the exercise method used, as the muscles are strengthened, the patient must also learn to use her muscles correctly to inhibit urinary urge and reduce stress incontinence episodes. She must learn to contract these muscles firmly in advance of a cough, sneeze, or similar anticipated stress. Strength without timing or timing without strength will result in clinically unsatisfactory results. Once the muscles are strengthened and the patient has learned to squeeze at the appropriate time, the extent of exercise needed to maintain the effect is not fully known. Like many exercise programs, the patient's dedication to the activity likely will diminish with time.
Electrical Stimulation Therapy
Transvaginal electrical stimulation produces a contraction of the levator ani, external urethral sphincter, and anal sphincters, accompanied by a reflex inhibition of the detrusor and is dependent on a preserved reflex arc through the sacral micturition center in order to work. Electrical stimulation with a transvaginal probe reduces detrusor overactivity and stress urinary incontinence in approximately 50% to 70% of affected women. Two randomized trials comparing electrical stimulation to placebo or sham device have been performed. Sand and colleagues, using high frequency probes, reported objective “cure” or improvement in 48% of patients with stress urinary incontinence versus 13% improvement in the control group. Brubaker and co-workers reported on 121 women with urge, stress, and mixed incontinence. Participants used either a sham device or underwent electrical stimulation using a low-frequency, 20-Hz, 2-second to 4-second work–rest cycle for 20 minutes twice daily for 8 weeks. Detrusor overactivity was cured in 49% of women receiving electrical stimulation, but there was no statistically significant change in the percentage with detrusor overactivity in the sham device group. There was no statistical improvement in the women with stress urinary incontinence.
Typically, a transvaginal probe is used once or twice daily for 15 to 20 minutes. Symptom relief generally occurs within 6 to 8 weeks and continues with reduced stimulation (e.g., three times weekly). Like timed voiding and muscle training, this treatment is free of systemic adverse effects. The main drawback is the cost of rental or purchase, which may be out-of-pocket expense for many patients. Many third-party providers and Health Care Financing Administration (HCFA) have approved the use of electrical stimulation therapy for urinary incontinence making the treatment more affordable. Several devices approved by the U.S. Food and Drug Administration are available, and treatment can be home-based or, less commonly, office-based. Women with pacemakers should avoid this therapy unless other options are not available.
Implantable electrostimulators, such as InterStim, are now being used for patients with refractory urge incontinence. Before considering InterStim, all other treatment options should have been used properly, including transvaginal electrostimulation. InterStim requires insertion of a wire electrode, through an incision in the back and placement of a permanent stimulator, to the nerve root of S2, S3, or S4. The nerve root is stimulated and theoretically aberrant afferent signals to the spinal cord are blocked, decreasing bladder overactivity. Improvement of urgency and frequency symptoms ranges from 60% to 83%.
Vaginal and Urethral Devices
An increasing selection of vaginal and urethral devices is available and appears to be the fastest-growing type of incontinence therapy. Pessaries modified for use in incontinence provide additional suburethral pressure and are safe and reasonably effective. For some women, the placement of a vaginal tampon may provide adequate urethral support to prevent leakage during physical activities such as playing golf or tennis.
Both external and internal urethral barriers are becoming increasingly available. While not optimal for all patients, these devices can provide effective treatment for patients who leak only under known circumstances or perhaps to improve their quality of life while awaiting surgery. External barriers range from patches that fit over the urethral meatus to small suction cups that limit urine loss. Internal urethral barriers are available, but they have the distinct disadvantage of causing urinary tract infections and hematuria. Although effective in preventing urine loss, the devices are less than ideal because of these adverse effects. In addition, many women are not comfortable with the idea of placing something into or over their urethra or are not physically able to do so. The efficacy, cost, comfort, and adverse effects including urinary tract infection and skin irritation for each of these barriers must be considered. More experience is needed before recommendations can be made.
Pharmacotherapy
Detrusor Overactivity or Urge Incontinence
No ideal medication for the treatment of incontinence is available, primarily because of the unwanted side effects. In general, drug treatment is used for detrusor overactivity and is aimed at reducing inappropriate detrusor contractions (Table 48.9).
|
|
|
TABLE 48.9. Pharmacologic therapy for detrusor instability |
Drugs for detrusor overactivity are typically anticholinergic agents. Thus, the adverse effects include xerostomia or dry mouth, blurred vision, drowsiness, and constipation. Narrow-angle glaucoma is an absolute contraindication to the use of this class of medications, and they should be used cautiously in women with cardiovascular disease.
While other anticholinergic medications have been used clinically, oxybutynin chloride, propantheline, and tolterodine are the only medications in this class with scientific evidence of efficacy for treating detrusor overactivity. Oxybutynin chloride is available in generic formulations and in a longer-acting, once-a-day nongeneric formulation. Tolterodine, available in a once- or twice-a-day dosing form, may have fewer adverse effects when compared to generic oxybutynin chloride.
Because of the high side-effect profiles, the medications should be started at very low doses and increased according to the patient's symptoms of incontinence and adverse reactions. The medications can be self-titrated over a period of 6 to 8 weeks with written instructions. Since constipation is a common comorbid condition in the elderly, recommending a stool softener when initiating therapy should be considered.
Long-term compliance with incontinence medications is poor and usually ranges from 40% to 50%. This low compliance should be considered when selecting this mode of therapy and follow-up should be scheduled. The effectiveness of pharmacotherapy is poor in women whose incontinence is related to insensible loss (leakage that occurs without the patient's knowledge).
Stress Incontinence
Medications that stimulate α-receptors are used to increase urethral tone in an effort to reduce stress incontinence episodes. These medications stimulate α-receptors throughout the body (e.g., in the cardiovascular system) and may cause hypertension. Phenylpropanolamine and pseudoephedrine are the first-line pharmacologic therapy for women with stress incontinence.
Women with mixed urinary incontinence may benefit from imipramine hydrochloride, a tricyclic antidepressant. This medication offers a combination of anticholinergic medication for detrusor suppression and α-receptor sympathomimetic activity to increase urethral pressure.
Estrogen
The role of oral or vaginal estrogens in the management of overactive bladder or stress incontinence remains unclear. Prospective studies have shown little effect of oral combined estrogen/progestin therapy on lower urinary tract function, including prevention or improvement in urinary incontinence. Meta-analysis of prior studies has shown some improvement in nocturia secondary to estrogen therapy in postmenopausal women.
While many clinicians feel strongly that preoperative transvaginal estrogen therapy improves surgical outcome and tissue healing, further evaluation is needed.
Surgical Management
Surgical management of urinary incontinence has been reported since the early 1900s. With an aging United States population, there will be greater demand for surgical and nonsurgical treatment of incontinence. Estimates indicate the demand for services will increase 10.9% for women between the ages of 30 to 58 years and 80.7% for those between 60 to 89 years by 2020. Although hundreds of operations have been described, today there are basically three types of procedures used: a suburethral plication, a shelf or repositioning type of procedure, or a pubovaginal sling. The large number of reported procedures indicates that no single type of operation will cure all patients. Table 48.10 presents the studies that have included objective testing and highlights the handful of studies that have been prospective, randomized, controlled trials. Based on the clinical findings in each individual patient, the surgeon must select the procedure or combination of procedures that will most likely alleviate the condition. Selection of the antiincontinence procedure is determined by many factors including need for other concomitant abdominal or vaginal procedures to correct pelvic organ prolapse, history of prior repairs, urethral hypermobility, and overall health and surgical risks for the patient.
|
|
|
TABLE 48.10. Urinary incontinence procedures: objective cure rates |
Significant limitations in reviewing data on the surgical treatment of stress incontinence have been encountered. There is no standardized pre- or postoperative evaluation for the surgical treatment of stress incontinence. Variable lengths of follow-up, inconsistent outcome criteria, and reporting biases of operating surgeons make comparison of many clinical series nearly impossible. The 1996 revision of the Agency for Health Care Policy and Research Urinary Incontinence Clinical Practice Guidelines summarized that “the surgical literature is deficient in standards for describing the patient population, the type of incontinence, the method for accurate diagnosis, the techniques of the surgical procedure, or the outcome in different domains.” In 1997, the American Urologic Association completed a comprehensive, evidence-based review of the surgical literature on the treatment of stress incontinence. Minimal criteria for follow-up interval and reporting outcomes resulted in the elimination of over half the reported clinical series from the database. There were no standardized pre- and postoperative evaluations and uniformity in the terminology describing the surgical procedures. Limited, poorly defined outcome measures (e.g., “dry”, subjective vs. objective variables, “improved”—1 pad/day vs. 3 pads/day) with little accuracy in morbidity rates made comparison of the surgical literature impossible.
Although our understanding of the pathophysiology of stress incontinence is incomplete, most accept the current concepts of urethral hypermobility and intrinsic sphincter dysfunction as causes, whether alone or in combination. Einhorning believed that the proximal urethra descended beyond the pelvic diaphragm and thus beyond the sphere of influence of the abdominal cavity, and restoration of continence required the urethra be drawn back within the abdominal cavity. Reexamination of the anatomy of the female pelvis from both a structural and functional perspective has led to the current concept that poor support of the proximal urethra as a result of relaxation or detachment of the anterior vaginal wall is responsible for the hypermobility associated with stress incontinence. It is recognized that this is an incomplete explanation since the majority of women with hypermobility do not have stress incontinence. Thus, there must also be some abnormality in the function of the urethra in women with stress incontinence. Whether this dysfunction is a primary neurologic defect or muscular defect is not yet determined, but there is strong evidence that denervation plays an important role. Snooks and co-workers demonstrated that the denervation effects of vaginal birth and subsequent pudendal neuropathy are significantly associated with GSI.
A subset of women develop stress incontinence despite excellent support of the UVJ. The term “intrinsic sphincter deficiency” (ISD) was created to describe this condition. ISD is a weakness or defect in the intrinsic urethral sphincter, resulting in stress incontinence, and is generally considered a more severe type of stress incontinence which emphasizes decreased urethral sphincter function rather than urethra position or mobility. Whether there is an actual physiologic difference in these “types” of stress incontinence or their underlying pathophysiology is unknown. This distinction may be artificial, looking at the same problem of neuromuscular dysfunction along one continuous spectrum.
Traditionally, from a surgical standpoint, the distinction between the two types of stress incontinence has been used to determine the type of surgical procedure performed—colposuspension or pubovaginal sling. Hypermobile stress incontinence has generally been managed with the “urethral hammock” support using a colposuspension such as a Marshall-Marchetti-Krantz (MMK), Burch, or paravaginal repair. The surgical procedure's goal is to elevate and stabilize the UVJ.
Patients with ISD have been found to have lower success rates following retropubic urethropexies when compared to patients with urethral hypermobility and a better functioning urethra. Thus pubovaginal sling procedures employed to treat ISD are designed to restore compression and coaptation of the damaged urethral sphincteric mechanism.
While some surgeons continue to surgically treat these “types” of stress incontinence differently, many surgeons, both urologists and gynecologists, are increasingly using a pubovaginal sling for all patients with stress urinary incontinence. Because of the reported durability, the pubovaginal sling, in increasing numbers of practices, is being performed for patients with hypermobile stress incontinence without ISD. Cross and associates performed pubovaginal slings on such patients with a cure rate of 93% reported at 22 months.
In 1996, a review by Black found four prospective studies done to compare colposuspension with sling procedures. None reported a difference in cure rate although all had substantially less than 50% power to detect a significant difference and all defined surgical success differently. Only one study analyzed complication rates and found a statistically significant higher risk of complications after a sling operation including elevated postvoid residual urine, entry into the bladder, and uterine prolapse. One large retrospective trial suggested that colposuspension may be more effective than sling procedures (95% vs. 79%). Marinkovic and colleagues, in a retrospective review of 18 women having a Burch colposuspension and 18 women undergoing a pubovaginal sling, found that the Burch group had twice the number of postoperative complications, with comparable success. In contrast, Enzelsberger showed significant increases in postoperative voiding dysfunction in patients after pubovaginal sling (13%) that was not observed in Burch patients. Thus, there is no convincing evidence that the effectiveness of colposuspension and sling procedures differ. The differences may be in the complication rates for the two procedures. However, less than 150 patients have ever been included in prospective studies concerning these two surgeries. Two large, prospective trials comparing Burch colposuspension and pubovaginal sling are underway and should help determine the best procedure.
Suburethral Plication/Anterior Colporrhaphy
While most surgeons have abandoned the suburethral plication as an antiincontinence procedure, for a select group of patients, the Kelly-Kennedy plication is appropriate. Dr. Howard Kelly from Johns Hopkins University was the first to describe this operation in 1913. The technique has changed very little from his original description. Through an anterior vaginal incision, the vesicovaginal space is dissected bilaterally to the pubic rami. A series of plicating mattress sutures of either permanent or delayed-absorbable material are then placed beneath the UVJ and then subsequently, in any significant pubocervical fascial defect, below the urethra and bladder.
Although Dr. Kelly reported a more than 90% subjective success rate with his anterior vaginal repair, subsequent success rates in the literature have ranged from 31% to 69% with 1- to 5-year follow-up. One noteworthy exception to these figures, however, is two studies from Dr. R. Peter Beck of Canada. In his original series of 105 patients reported on in 1982, a 90% subjective cure rate was described. In a follow-up paper published in 1991, similar outcome numbers were provided for over 500 patients. Dr. Beck attributed much of his success to the use of delayed absorbable polyglycolic suture instead of chromic cat gut suture.
Anterior vaginal repair remains indicated in the treatment of a cystocele caused by a central fascial defect. Concomitant suburethral plication may be a reasonable choice in the prevention of potential or occult stress incontinence for patients having vaginal reconstruction for pelvic organ prolapse. The most appropriate indication for a suburethral plication is in conjunction with an obliterative procedure, such as when complete or LaForte colpocleisis is performed. These patients, generally older with poorly functioning detrusor muscles or detrusor overactivity, are at risk for urinary retention or worsening of incontinence from detrusor contractions if a more durable antiincontinence surgery is performed. A suburethral plication may be the best antiincontinence surgery for these patients. Their incontinence may not be “cured”, but the low morbidity balances the higher risks of urinary retention or overactive bladder. Success in these cases is defined by improved quality of life from prolapse surgery and hopefully a reduction in urinary incontinence and avoidance of self-catheterization.
Complications include hemorrhage, vaginal foreshortening, and suture misplacement in the bladder, urethra, or ureter. Thus, follow-up cystoscopic evaluation is recommended to assess for potential injury to the lower urinary tract.
Retropubic Urethropexy
Retropubic urethropexy (RPU) is used by many surgeons as their primary repair for stress incontinence. The first RPU, described in 1949, the Marshall-Marchetti-Krantz (MMK) procedure has had success rates ranging from 70% to 90%. After entry to the retropubic space is achieved, the urethra is identified along its course to the bladder neck. One to three pairs of sutures, usually nonabsorbable, are placed on each side and close to the urethra through the pubocervical fascia. These are then fixed to the fibrocartilage of the symphysis pubis. Because the angle of elevation is more acute and centrally placed than with a Burch procedure, the potential exists for the patient to have an increased risk of bladder neck obstruction. Voiding dysfunction occurs in 5% to 20% of cases. The rate of subsequent osteitis pubis is approximately 2%.
In 1961, Dr. John Burch of Nashville, Tennessee described a new fixation point for the RPU sutures, namely Cooper's ligament. Through a Pfannenstiel incision, the retropubic space is entered. With the surgeon's nondominant hand in the patient's vagina, the Foley catheter is pulled down to the UVJ. While gently retracting the bladder medially, the paravaginal tissues are identified and, if necessary, gently cleaned off at the UVJ and midurethra extending approximately 2 cm lateral to the urethra. Seeing the white surface of the vaginal submucosal layer in contrast to the yellow bladder helps identify the vagina. A full thickness figure-of-eight of permanent suture is placed at the UVJ and midurethra on both sides. Cooper's ligament is identified, and both arms of the sutures are brought through the ligament, with the midurethral sutures most caudad (Fig. 48.6). The sutures are tied while elevating the vagina so that the urethra is repositioned parallel to the floor. Overcorrection should be avoided; suture bridges are the norm. Cystoscopy, transurethrally or through the bladder dome, teloscopy, is then performed to assess the integrity of the lower urinary tract. Consideration for placement of a suprapubic catheter is reasonable, especially if the patient is predisposed to postoperative voiding dysfunction.
|
|
|
FIG. 48.6. Burch retropubic urethropexy. Sutures are placed lateral to the urethrovesical junction and lateral to the midurethra and brought to the Cooper ligament bilaterally. (Adapted from Tanagho EA. Colpocystourethropexy: the way we do it. J Urol 1976;116:751.) |
Objective cure rates for the Burch RPU range from 70% to 90%. Complications include ureteral damage (usually from overcorrection or kinking, not direct trauma) and bleeding from the adjacent large veins of Santorini. Enterocele formation following colposuspension has been reported in 3% to 17% of patients, leading most surgeons to perform a uterosacral ligament plication or cul-de-sac obliteration for patients predisposed to pelvic organ prolapse. The prevalence of postoperative detrusor overactivity is 5% to 18%.
Postoperative management is similar to that for other abdominal surgical procedures. It is usually possible to allow patients to have oral intake soon after the operation, because the peritoneal cavity was not entered. The bladder is drained continuously for the first 1 or 2 postoperative days. If used, the suprapubic catheter is occluded and patients are asked to indicate when they feel that the bladder is full. They are then allowed to void, and the amount of urine remaining inside the bladder is measured by the nursing personnel. If transurethral catheter drainage has been used, the bladder can be filled retrograde until the patient feels full. The catheter is then removed and the patient is asked to void. The voided amount is measured using a hat placed in the toilet. By subtracting the voided amount from the amount instilled in the bladder, the postvoid residual can be determined. The catheter should be replaced or the suprapubic catheter should be left in until the patient is able to void adequately with small amounts of residual urine (<100 mL or <25% of the total volume in the bladder) consistently for three voids. The patient can also be taught clean, intermittent self-catheterization to perform until her postvoid residuals are adequate. Most patients can void adequately within 72 hours.
Some literature suggests that the Burch procedure has fewer complication rates than the MMK. Columbo and colleagues randomized 80 patients with stress incontinence to receive either a Burch or an MMK. Although the cure rates were equal, patients who underwent an MMK were more likely to have detrusor overactivity and voiding dysfunction postoperatively.
Laparoscopic Bladder Neck Suspension
The laparoscopic approach to correcting stress incontinence has been described with increasing frequency since the early 1990s. Reports by expert laparoscopic surgeons who perform the Burch procedure identical to the open technique report similar success rates to the open procedure. Reports where techniques are altered, such as one suture used on each side rather than two, or only one arm of the suture being brought through Cooper's ligament have shown significantly more failures. The applicability of this technique demands that the procedure be performed in exactly the same way as an open Burch.
Complications with the laparoscopic technique include injuries to nearby structures at the time of surgery and are more frequent than with open dissection. This is most likely due to the learning curve. Most skilled laparoscopists cite a learning curve of 10 to 20 procedures.
Paravaginal Repair
Paravaginal repair is another retropubic procedure used for the correction of stress incontinence. The abdominal paravaginal repair was first described by Burch, in his initial attempts to surgically support the UVJ. Due to poor results, Burch modified his procedure, elevating the sutures from the endopelvic fascia to Cooper's ligament rather than the arcus tendineus fasciae pelvis (ATFP). Cullin Richardson reintroduced paravaginal repair as a procedure to correct paravaginal (lateral) defects in anterior vaginal wall support. Although others have suggested that the procedure may also be used as an antiincontinence surgery, closer examination of the procedure performed indicates that the investigators combined Burch stitches to the Cooper ligament with paravaginal stitches to the ATFP. The only randomized, prospective study comparing the Burch procedure to a pure paravaginal repair, with pre- and postoperative objective follow-up, indicates that the paravaginal repair yields inferior cure rates, 75% versus 100%, in treating stress incontinence. The paravaginal repair should be considered a procedure for correcting anterior lateral vaginal wall defects and not as an antiincontinence procedure.
Suburethral Slings
Suburethral sling procedures have been described since the early 1900s. In 1942, Aldridge was the first surgeon to use strips of autologous rectus fascia, placing it under the bladder neck and affixing it to the anterior abdominal wall.
Traditionally, suburethral slings have been performed for recurrent stress incontinence, for patients with risk factors for surgical failure such as chronic pulmonary conditions like asthma, or for patients who perform physically demanding activities that cannot be modified. The more common indication is for ISD with or without urethral hypermobility. There has also been a trend in performing primary sling procedures in patients with hypermobile stress incontinence based on the high failure rates of other procedures, particularly, anterior repair and needle suspensions.
Suburethral sling procedures may use autologous materials or foreign materials to support the UVJ. Autologous materials such as fascia lata may be obtained from the leg, or rectus fascia from the anterior abdominal wall has also been used. Synthetic materials such as Marlex and Mersilene have been used for suburethral slings with success. Allograft fascia has been used with varying success rates depending on tissue source and processing. Surgeons continue to search for the ideal sling material. While autologous materials have fewer long-term complications such as erosion or infection, the harvesting of grafts increases operative time and potential for morbidity.
The technique of a suburethral sling procedure basically involves placement of either a tissue or synthetic graft under the bladder neck and fixation of the material to an abdominal site. A graft measuring approximately 8- to 10-cm long by 2-cm wide is either harvested or cut from the synthetic material and tagged at the corners with permanent suture. The vaginal portion of the procedure begins with a vertical or U-shaped incision made along the anterior vaginal wall, and entry into the retropubic space is accomplished. The UVJ is identified by gently pulling on an indwelling Foley catheter. The sling itself will be sutured such that two-thirds of the 2-cm–wide sling are under the urethra and one-third is under the trigone (Fig. 48.7).
|
|
|
FIG. 48.7. Suburethral sling procedure. After dissection of the anterior vaginal wall, the sling is anchored underneath the urethrovesical junction, and the arms are brought to the anterior rectus fascia, where they are similarly anchored. (Adapted from Horbach N, Blanco J, Ostergard DR, et al. A suburethral sling procedure with polytetrafluoroethylene for the therapy of genuine stress incontinence in patients with low urethral closure pressure. Obstet Gynecol1988;71:648.) |
A short suprapubic incision is made to the level of the anterior rectus fascia. A stab wound is made through the rectus fascia 2.5 cm lateral to the midline just above the symphysis. A uterine packing forceps or suture carrier is passed through this incision down into the vagina, guided by the surgeon's index finger. The arm of the sling is grasped and withdrawn up to the anterior rectus fascia. The procedure is repeated on the opposite side. At this point, a cystoscope is introduced into the bladder to ascertain whether or not perforation of the bladder has occurred and urethral function remains normal. The sling is then secured at the UVJ using fine absorbable suture. The sling is then gently elevated until there is no slack. The most important step in the procedure is paying careful attention to not to pull the sling too tight. The sling functions as a backstop, not by occluding the urethra. Experienced surgeons know that loose is better than tight. While various techniques including Q-tip angles and cystoscopy have been used to try and “standardize” sling tension, none have proven useful. The sling is sutured first to the rectus fascia. The anterior vaginal wall is approximated and the anterior abdominal wall incision is closed. Postoperative care and bladder management is the same as described for colposuspension.
Complications of the suburethral sling procedure include the possibility of erosion of the sling material into the vagina or the anterior abdominal wall with sinus tract formation. Occasionally, slings must be removed because of this problem. Slings may also be removed from patients who develop marked obstruction and who do not want to use self-catheterization on a permanent basis.
Success rates for sling procedures range from 85% to 90%. Reasons for failure include inaccurate placement at the bladder neck, inadequate sling tension, poor tissue graft, or inadequate fascial attachment. The most common complication and the reason many surgeons avoid sling procedures is postoperative voiding dysfunction. Failure to void after the procedure occurs in up to 20% of patients. Although there are procedures designed to remedy this situation (i.e., sling release or modification), the best method is prevention by assuring that the sling is not placed too tightly in the first place. Some patients may be able to modify their urination by changing positions such as leaning forward or standing. As long as the patient is not having serious sequelae such as pain or urinary tract infections, treatment may remain conservative. The patient may very well be willing to accept some voiding difficulty in exchange for being dry. If however, the patient cannot spontaneously void by 6 weeks after surgery, sling revision should be offered. In most cases, the sling can be cut transvaginally and the patient does not develop recurrent incontinence.
Tension-free Vaginal Tape
In 1995, a modification of the pubovaginal sling, the tension-free vaginal tape (TVT), was introduced. Developed by Petros and Ulmsten in Sweden, the TVT differs from the traditional pubovaginal sling in that the sling is placed at the midurethra and not the UVJ, and the sling material is a 1-cm–wide mesh of Prolene that is held in place by friction and not sutures. The procedure, designed to be performed under local or regional anesthesia, allows the patient to cough with a full bladder during sling adjustment. The sling is elevated to the level where urine leakage stops and is not made any tighter.
For women with hypermobility and a normal functioning urethra, an objective cure rate of 90% has been reported after a 5-year follow-up. For a small group of women with ISD, cure rates of 74% with additional improvement in 12% with a 4-year follow-up have been reported.
Immediate complications, including bleeding and bladder perforation, are similar to other series for pubovaginal slings. Voiding dysfunction appears to be less than for traditional pubovaginal slings, but is probably related to having a looser sling. As more surgeons have adapted the loose sling technique to traditional sling placement, the voiding dysfunction in more recent series is also decreasing.
Long-term complications, including graft erosion, are unknown. While Prolene appears to have properties that are more favorable for vaginal placement than other meshes, it is likely that there will be a 1% to 3% erosion rate. Longer follow-up and careful reporting of outcomes will determine the use of TVT in the management of stress urinary incontinence.
Transurethral Collagen Injections
Although initially thought to be a significant breakthrough in treating patients with severe incontinence, periurethral bulking agents have a less than 50% long-term success rate. However, for some patients this is a reasonable surgical alternative to more invasive procedures. The patient best suited for a bulking agent is one who has ISD, an immobile bladder neck, excessive surgical risk, and who has undergone multiple antiincontinence procedures. Short-term cure rates approach 70% to 90%. Periurethral collagen injections are not indicated in women with urethral hypermobility, because cure rates are only 20% to 25% in this group of women.
The most commonly used substance for bulking is gluteraldehyde cross-linked bovine collagen. Because of potential allergies, a patient must have a negative reaction to a collagen skin test weeks before surgery. The procedure can be done in the physician's office or in an outpatient setting with local anesthesia. A zero-degree operative cystoscope with a spring-mounted injection needle is employed. Once the bladder neck is visualized, a site approximately 1 to 2 cm distal to it is selected for needle insertion. Injections are performed at the 3 o'clock and 9 o'clock positions in an attempt to close the bladder neck. Usually, 5 to 7 cc of material will be sufficient. The patient is asked to cough to observe for leakage.
Injections can last 3 months to several years. Most patients require multiple injections given 2 to 3 months apart, followed by a general improvement lasting 6 months to 1 year.
This method is probably best used by obstetrician–gynecologists who specialize in the treatment of incontinence.
Artificial Urinary Sphincters
Few treatment centers implant artificial urinary sphincters in women, mostly because of the high complication rates. The ideal patient has ISD but no scarring at the bladder neck. Failure of a sling procedure or collagen injections may prompt the surgeon to consider this surgery. The sphincter is placed using a combined abdominal/vaginal approach. The sphincter is placed around the urethra, with the reservoir in the retropubic space and the pump in the labia majora. The active sphincter mechanism is not activated for 6 weeks until healing has taken place. The device maintains closure of the bladder neck until patient activation of the device evacuates the cuff for several minutes to allow voiding. Complications include infection, device erosion, or pump failure.
SELECTING THE APPROPRIATE SURGICAL PROCEDURE FOR STRESS INCONTINENCE
Selection of a surgical procedure for a given patient is based on the operating surgeon's impression of the clinical complaints, the physical examination findings, and cystometric values. Objective urodynamic assessment of the patient is only required if the surgeon is going to base the choice of surgical procedure on specific objective findings such as the urethral closure pressure or the bladder pressure needed to overcome the urethra. If however, the surgeon will perform a pubovaginal sling, for all patients with stress incontinence regardless of urethral function, then urodynamic testing in not indicated.
Traditionally, if a patient's urethral pressure has been considered normal, greater than 20 cm H2O, a retropubic urethropexy of the Burch type is preferred. If the urethral pressure is less than 20 cm H2O, a suburethral sling procedure should be considered. In both circumstances, it is assumed that inadequate support of the UVJ is present, as indicated by a Q-tip test that is greater than 30 degrees from the horizontal during straining. If the UVJ is well supported, as indicated by a Q-tip deflection on straining of less than 30 degrees from the horizontal, the patient is less likely to respond to either of the aforementioned procedures, and other surgical means may be indicated for treatment. Options for treatment of intrinsic sphincter deficiency and a supported bladder neck include an artificial sphincter, periurethral injection, or an obstructive sling. With the latter choice, the patient needs to be informed of the extremely high probability that lifelong self-catheterization may be required to empty the bladder.
Much discussion has taken place regarding the different procedures used to manage stress incontinence in regard to efficacy and long-term success. Unfortunately, most studies in the literature have lacked objective pre- and postoperative assessment and therefore an objective measurement of cure. Table 48.10 shows the studies that have included objective testing and highlights the handful of studies that have been prospective, randomized, controlled trials.
SUMMARY
Many women of all ages have urinary incontinence. Unfortunately, many women still do not seek treatment. All clinicians who care for women should ask about bladder function and reassure patients that many successful treatments are available. After asking the question, the clinician should work with the patient to determine the type and severity of her incontinence and the impact her urine leakage is having on her life. Evaluation should be directed at ruling out treatable causes such as urinary tract infections, fluid overload, or medications that affect fluid balance or lower urinary tract function. Bladder testing with cystometry should be considered before surgical treatment to be sure the patient suffers from stress incontinence and not detrusor overactivity that may be made worse or have no improvement after surgery. Treatment should be based on the patient's expectations, ability to use behavioral techniques, side effects of therapies, cost, and success for treating her condition.
SUMMARY POINTS
· Urinary incontinence is a common condition affecting women. Many successful treatment options are available.
· Diagnosis of lower urinary tract conditions, particularly urinary incontinence, cannot be made based on symptoms alone. A systematic approach including history, physical examination, voiding diary, assessment of postvoid residual, and ruling out infection begin the assessment.
· A positive stress test demonstrates the sign of stress urinary incontinence.
· Multichannel urodynamic studies are indicated for approximately 10% of women to help make the diagnosis of the type of urinary incontinence. Clinicians who specialize in urinary incontinence use multichannel urodynamics to test more patients because of the complexity and prior failed treatments in women referred for subspecialty care.
· Selection of the appropriate surgical procedure for the correction of stress incontinence should be based on urethral function, the presence or absence of urethrovesical junction (UVJ), hypermobility, and the need for other surgical procedures for pelvic organ prolapse.
· Retropubic urethropexy procedures, specifically the modified Burch procedure, offer the best long-term support of the UVJ and cure of incontinence with the least morbidity.
· Intrinsic sphincter deficiency should be considered in patients with severe leakage with minimal activity or those with recurrent incontinence, a history of radical pelvic surgery, or radiation. Options for therapy include periurethral injection of bulking agents or artificial sphincter in patients with a well-supported UVJ, or a suburethral sling when UVJ hypermobility is present.
· Detrusor overactivity should be looked for in every patient with urinary incontinence, most importantly prior to any surgical antiincontinence procedure. It is best treated with bladder retraining, electrical stimulation therapy, or anticholinergic medications.
SUGGESTED READINGS
Definition of Terms
Abram P, Cardozo L, Fall M, et al. The standarisation of terminology of lower urinary tract function: report from the Standardisation Sub-Committee of the International Continence Society. Neurourol Urodyn 2002;21:167–178.
Epidemiology
Bump RC, Norton PA. Epidemiology and natural history of pelvic floor dysfunction. Obstet Gynecol Clin North Am 1998;25:723.
Farrell SA, Allen VM, Baskett TF. Parturition and urinary incontinence in primiparas. Obstet Gynecol 2001;97:350.
Fultz NH, Herzog AR, Raghunathan TE, et al. Prevalence and severity of urinary incontinence in older African American and Caucasian women. J Gerontol1999;54A:M1–5.
Herzog AR, Fultz NH. Prevalence and incidence of urinary incontinence in community-dwelling populations. J Am Geriatr Soc 1990;38:273.
Luber K, Choe JY, Boero S. Demographics and distribution of disease among women seeking care for incontinence and prolapse; current observations and future projections. Int Urogynecol J 1999;10:S10.
Thom DH, Brown JS. Reproductive and hormonal risk factors for urinary incontinence in later life: a review of the clinical and epidemiologic literature. J Am Geriatr Soc 1998;46:1411–1417.
Wilson L, Brown JS, Shin GP et al. Annual direct cost of urinary incontinence. Obstet Gynecol 2001;98:398-406.
Evaluation of Urinary Incontinence
Brubaker L. Initial assessment: the history in women with pelvic floor problems. Clin Obstet Gynecol 1998;41:657.
Fantyl JA, Newman DK, Colling J, et al. Urinary incontinence in adults: acute and chronic management. Clinical Practice Guidelines Number 2, 1996 Update.Rockville, MD: Agency for Health Care Policy and Research, US Dept of Health and Human Services; 1996. AHCPR publication 96-0682.
Howard D, DeLancey JOL, Tunn R, et al. Racial differences in the structure and function of the stress urinary incontinence mechanism in women. Obstet Gynecol 2000;95:713.
Nonsurgical Management of Urinary Incontinence
Abrams P, Freeman R, Anderstrom C, et al. Tolterodine, a new antimucharinic agent: as effective but better tolerated than oxybutynin in patients with an overactive bladder. Br J Urol 1998;81:801.
Brubaker L, Benson JT, Bent A, et al. Transvaginal electrical stimulation for female urinary incontinence. Am J Obstet Gynecol 1997;177:536.
Miller JM, Aston-Miller JA, DeLancey JOL. A pelvic muscle precontraction can reduce cough-related urine loss in selected women with mild SUI. J Am Geriatr Soc 1998;46:870.
Nygaard IE, Kreder KJ, Lepic MM, et al. Efficacy of pelvic floor muscle exercise in women with stress, urge, and mixed incontinence. Am J Obstet Gynecol1996;174:120.
Sand PK, Richardson DA, Staskin DR, et al. Pelvic floor electrical stimulation in the treatment of stress incontinence: a multicenter, placebo-controlled trial. Am J Obstet Gynecol 1995;173:72.
Surgical Management of Urinary Incontinence
Bergman A, Elia G. Three surgical procedures for stress urinary incontinence: five-year follow-up of a prospective randomized trial. Am J Obstet Gynecol1995;173:66.
Black NA, Downs SH. The effectiveness of surgery for stress incontinence in women: a systematic review. Br J Urology 1996;78:497–510.
Breen JM, Geer BE, May GE. The fascia lata suburethral sling for treating recurrent urinary stress incontinence. Am J Obstet Gynecol 1997;177:1363.
Chaikin DC, Rosenthal J, Blaivas JG. Pubovaginal fascial sling for all types of stress urinary incontinence: long-term analysis. J Urol 1998;160:1312.
Columbo M, Milani R, Vitobello D, et al. A randomized comparison of Burch colposuspension and abdominal paravaginal defect repair for female stress urinary incontinence. J Urol 1997;158:875.
Columbo M, Scalambrino S, Maggioni A, et al. Burch colposuspension versus Marshall-Marchetti-Krantz urethropexy for primary stress urinary incontinence: A prospective randomized clinical trial. Am J Obstet Gynecol 1994;171:1573.
Cross CA, Cespedes RD, McGuire EJ. Our experience with pubovaginal slings in patients with stress urinary incontinence. J Urol 1998;159:1195–1198
Diokno AC, Hollander JB, Alderson TP. Artificial urinary sphincters for recurrent female urinary incontinence: indications and results. J Urol 1987;137:778.
Gorton E, Stanton S, Monga A, et al. Periurethral collagen injection: a long-term follow-up study. Br J Urol 1999;84:966.
Henriksson L, Ulmsten U. A urodynamic evaluation of the effects of abdominal urethrocystopexy and vaginal sling urethroplasty in women with stress incontinence. Am J Obstet Gynecol 1978;131:77–82.
Kreder KJ, Austin JC. Treatment of stress urinary incontinence in women with urethral hypermobility and intrinsic sphincter deficiency. J Urol1996;156:1995–1998.
Leache GE, Dmochowski RR, Appell RA, et al. Female stress urinary incontinence clinical guidelines panel summary report on surgical management of female stress urinary incontinence. J Urol 1997;158:875.
Marinkovic S, Mian H, Evanlovich M, et al. Analysis of early outcome: Burch procedure versus pubovaginal sling. Int Urogynecol J Pelvic Floor Dysfunc1998;9:94.
Milani R, Scalambrino S, Quadri G, et al. Marshall-Marchetti-Krantz procedure and Burch colposuspension in the surgical treatment of female urinary incontinence. Br J Obstet Gynaecol 1985;92:1050–1053.
Nilsson CG, Kuuva N, Falconer C, et al. Long-term results of the tension-free vaginal tape (TVT) procedure for surgical treatment of female stress urinary incontinence. Int Urogynecol J 2001;1:S5–S8.
Ross JW. Laparoscopic Burch repair compared to laparotomy Burch for cure of urinary stress incontinence. Int Urogynecol J 1995;6:323.
Stanton S, Cardozo L. A comparison of vaginal and suprapubic surgery in the correction of incontinence due to urethral sphincter incompetence. Br J Urol1979;51:497–499.
Van Geelen JM, Theeuwes AG, Eskes TK, et al. The clinical and urodynamic effects of anterior vaginal repair and Burch colposuspension. Am J Obstet Gynecol 1988;159:137–144.
