Chapter 4 |
109 |
Incontinence |
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Classification 110
Causes and pathophysiology 112 Evaluation 114
Treatment of sphincter weakness incontinence: injection therapy 116
Treatment of sphincter weakness incontinence: retropubic suspension 117
Treatment of sphincter weakness incontinence: pubovaginal slings 118
Treatment of sphincter weakness incontinence: the artificial urinary sphincter 120
Overactive bladder: conventional treatment 122 Overactive bladder: options for failed conventional
therapy 124
“Mixed” incontinence 126 Post-prostatectomy incontinence 128 Vesicovaginal fistula (VVF) 130 Incontinence in the elderly patient 132
110 CHAPTER 4 Incontinence
Classification
Definition
The International Continence Society (ICS) defines incontinence as “involuntary loss of urine that is a social or hygienic problem and is objectively demonstrable.” Urinary incontinence (UI) is a failure to store urine usually due to either abnormal bladder smooth muscle or a deficient urethral sphincter. Urine loss may also be extraurethral, secondary to anatomical abnormalities such as ectopic ureter or vesicovaginal fistula.
Prevalence
UI has been reported to affect 12–43% of adult women and 3–11% of adult men. Severe incontinence has a low prevalence in young women, but rapidly increases at ages 70 through 80. Incontinence in men also increases with age, but severe incontinence in 70to 80-year-old men is about half that in women.
Classification
Stress urinary incontinence (SUI) is involuntary urinary leakage during effort, exertion, sneezing, or coughing, due to hypermobility of the bladder base, pelvic floor, and/or intrinsic urethral sphincter deficiencies. In females SUI is usually associated with multiparity. In males, SUI is most commonly the result of prostatectomy.
•Type 0—report of urinary incontinence, but without clinical signs
•Type I—leakage that occurs during stress with <2 cm descent of the bladder base below the upper border of the symphysis pubis
•Type II—leakage on stress accompanied by marked bladder base
descent (>2 cm) that occurs only during stress (IIa) or is permanently present (IIb)
•Type III—bladder neck and proximal urethra are open at rest (with or without descent). Also known as intrinsic sphincter deficiency (ISD)
Urge urinary incontinence (UUI) is involuntary urine leakage accompanied or immediately preceded by a sudden, strong desire to void (urgency).
Mixed urinary incontinence is urine leakage that has characteristics of both SUI and UUI.
Overflow incontinence is leakage of urine when the bladder is abnormally distended with large post-void residual volumes. Typically, men present with chronic urinary retention and dribbling incontinence. This can lead to hydronephrosis and renal failure in 30% of patients.
Nocturnal enuresis describes any involuntary loss of urine during sleep. The prevalence in adults is 0.5%. Approximately 750,000 children over age 7 years will regularly wet the bed. Childhood enuresis can be further classified into primary (never been dry for longer than a 6-month period) or secondary (re-emergence of bed wetting after a period of being dry for at least 6–12 months).
CLASSIFICATION 111
Post-micturition dribble is the complaint of a dribbling loss of urine that occurs after voiding. It predominantly affects males and is due to pooling of urine in the bulbous urethra after voiding. It affects approximately 20% of healthy adults1 and 60–70% of those with existent LUTS.2
1 Furuya S, Ogura H, Tanaka M, et al. (1997). Incidence of postmicturition dribble in adult males in their twenties through fifties. Hinyokika Kiyo 43(6):407–410.
2 Paterson J, Pinnock CB, Marshall VR (1997). Pelvic floor exercises as a treatment for postmicturition dribble. Br J Urol 79(6):892–897.
112 CHAPTER 4 Incontinence
Causes and pathophysiology
Risk factors
Predisposing factors
•Gender (female > males)
•Race (Caucasian > African American/Asian)
•Genetic predisposition
•Neurological disorders (spinal cord injury, stroke, MS, Parkinson disease)
•Anatomical disorders (vesicovaginal fistula, ectopic ureter, urethral diverticulum)
•Childbirth
•Anomalies in collagen subtype
•Prostate or pelvic surgery (radical prostatectomy; radical hysterectomy; TURP) leading to pelvic muscle and nerve injury
•Pelvic radiotherapy
Promoting factors
•Smoking (associated with chronic cough and raised intra-abdominal pressure)
•Obesity
•UTI
•Increased fluid intake
•Medications
•Poor nutrition
•Aging
•Cognitive deficits
•Poor mobility
Pathophysiology
Bladder abnormalities
Detrusor overactivity is a urodynamic observation characterized by involuntary bladder muscle (detrusor) contractions during the filling phase of the bladder, which may be spontaneous or provoked, and can consequently cause urinary incontinence. The underlying cause may be neurogenic, where there is a relevant neurological condition, or idiopathic, where there is no defined cause.
Low bladder compliance is characterized by a decreased volume-to-pres- sure relationship during a cystometrogram and is often associated with upper tract damage. High bladder pressures occur during filling because of alterations in the viscoelastic properties of the bladder wall, or changes in bladder muscle tone (secondary to myelodysplasia, spinal cord injury, radical hysterectomy, interstitial or radiation cystitis).
Sphincter abnormalities
Urethral hypermobility is due to a weakness of pelvic floor support causing a rotational descent of the bladder neck and proximal urethra during increases in intra-abdominal pressure. If the urethra opens concomitantly, there will be urinary leaking.
CAUSES AND PATHOPHYSIOLOGY 113
Intrinsic sphincter deficiency (ISD) describes an intrinsic malfunction of the sphincter, regardless of its anatomical position, which is responsible for type III SUI. Causes include inadequate urethral compression (previous urethral surgery; aging; menopause; radical pelvic surgery) or deficient urethral support (pelvic floor weakness; childbirth; pelvic surgery; menopause).