Epidemiology

Epidemiology

Urinary incontinence is highly prevalent, a ff ecting 25–45% of men and women, and this increases with age. In men, the most common cause of SUI is radical prostatectomy for prostate cancer, with prevalence estimates of 5% at 24–36 months after surgery . Continence is primarily dependent on normal bladder compli ance, an intact urethral sphincter, strong urethral support by the pelvic floor and a leakproof mucosal seal. Compliance is the ability of the bladder to expand in vol ume without any significant rise in pressure, and during the normal storage phase the bladder pressure remains lo maximum capacity is reached. This enables normal renal drainage and is dependent on the viscoelastic properties of the bladder wall (low collagen le vels). However, detrusor over activity during the storage phase, bladder muscle hypertrophy or increased levels of bladder wall collagen (e.g. due to fibro sis) can all reduce compliance and lead to incontinence and deterioration in renal drainage. This may occur as a result of pelvic surgery , irradiation, neurological conditions, chronic inflammatory b ladder conditions leading to bladder fibrosis or longstanding bladder outlet obstruction. Deficiencies in the active urethral sphincter mechanism, the urethral mucosal seal and the pelvic floor support contrib ute to varying degrees of SUI. Hypermobility of the bladder base and proximal urethra due to laxity of the usual supporting ‘hammock’, consisting of endopelvic and pubocervical fascia attac hed to the ATFP and levator ani, is thought to lead to dis placement of the urethra out of the pelvis. As a result, during stress manoeuvres the raised intra-abdominal pressure is not transmitted to the urethra and so incontinence occurs. Laxity of the vaginal wall and pubourethral ligaments is thought to contribute to this deficiency in urethral support. These theories are the basis for retropubic suspension and mid-urethral sling procedures to treat SUI. Intrinsic sphincter deficiency occurs when the normal submucosal vascularity of the urethra and sphincter muscle tone are deficient. This may occur as a result of previous surgery , causing fibrosis, irradiation and nerve injury , or loss of oestrogenisation. Hypermobility and intrinsic sphincter deficiency exist on a spectrum and most women with SUI have elements of both. /uni25CF /uni25CF /uni25CF /uni25CF /uni25CF /uni25CF /uni25CF /uni25CF /uni25CF /uni25CF /uni25CF /uni25CF /uni25CF /uni25CF /uni25CF /uni25CF - When evaluating patients with urinary incontinence, the history should ascertain whether symptoms are predominantly SUI, UUI or MUI, and should assess their impact on the patient’s - quality of life. Predisposing and exacerbating factors should be treated where possible ( Table 83.5 ). The body mass index w until (BMI) should be noted and patients advised to lose weight if this is elevated. Abdominal examination to identify a palpable bladder suggestive of chronic urinary retention, and vaginal - examination to assess pelvic floor tone and oestrogenisation status and to identify pelvic organ prolapse, should also be - performed. Neurological examination to assess anal tone and sensation and lower limb function will aid identification of a neurological lesion.

TABLE 83.5 Predisposing and exacerbating factors for urinary incontinence (UI) Predisposing Exacerbating Familial (increased risk in Age those with family history of Obesity UI) Increased intra-abdominal pressure (chronic cough, Congenital or acquired straining due to constipation, anatomical abnormalities (e.g. exercise) ectopic ureter, urinary tract /f_i stulae, urethral diverticulum) Cognitive impairment Neurological conditions (e.g. Restricted mobility spina bi /f_i da, spinal cord Urinary tract infection injury, Parkinson’s disease, Drugs (e.g. diuretics) stroke, multiple sclerosis) Menopause causing atrophic vaginitis Pregnancy and childbirth Pelvic surgery Fluid intake (e.g. excess caffeine) Pelvic radiotherapy Chronic in /f_l ammatory conditions resulting in bladder /f_i brosis (tuberculous cystitis, ketamine cystitis, interstitial cystitis)