Urinary Incontinence

Urinary Incontinence Involuntary loss of urine from the bladder Incidence approx 10-20% (once a month or more) and increases with age Continence mechanism Proximal sphincter - at level of bladder neck AV anastomoses in wall of proximal urethra which occlude urethra. Proximal sphincter is held intra-abdominally by support tissues (pubourethral ligaments and levator ani) so raise in pressure affects bladder & urethra = maintains seal. Weakness or damage of this --> genuine stress incontinence eg during childbirth damage to nerves / musculature Distal sphincter – muscle based (part of levator ani) innervated by S2-4 Detrussor muscle – should only contract when appropriate. If overactive can --> urge & urge incontinence Presentation Stress incontinence – leaks on activity (sneezing, coughing, walking etc) & may include leaking on way to toilet Urgency – irresistible desire to pass urine (common in overactive bladder) Urge incontinence – incontinence assoc with urgency desire (common in overactive bladder) Nocturnal enuresis – assoc with overactive bladder Voiding difficulty – hesitancy, poor stream, incomplete emptying ALWAYS – document effect of symptoms on lifestyle Consider prolapse, anorectal symptoms, other possible causes (infection, surgery etc) O/E Limited use in diagnosis Excoriation of vulva may indicate long term problem Ask patient to cough to establish stress incontinence Look for prolapse Neurological assessment of S2-4 (& lower limb) is important Investigations MSU – microorganisms indicate infection, sterile pyuria indicates chronic bladder/renal infection (eg TB), red cells may indicate tumour Frequency Volume chart – aka urinary diary. Chart fluid intake & output volumes & frequency Urodynamic assessment – filling (cystometrogram) bladder is filled by urethral catheter at 100ml/min & detrussor pressure measured. Should show genuine stress incontinence. Voiding urodynamics – measures peak flow, detrussor activity to obtain that flow, total volume voided & residual volume. Should be performed on all women with voiding symptoms Genuine stress incontinence Commonest cause in adult women Due to raised abdominal pressure with absence of detrusor activity (sneeze, cough etc) & failure of sphincters Predisposing factors Pregnancy – vaginal delivery may denervate pudendal nerve --> sphincter damage. Also progesterone is muscle relaxant so may occur during pregnancy Prolapse – deficiency of support tissues is associated with both Menopause – oestrogen withdrawl reduces maximal urethral closure pressure Collagen disorder – causes stretching of ligaments & fascia Obesity – increased intraabdo pressure Treatment Conservative Pelvic floor exercises – strengthens muscles Vaginal cones – similar to pelvic floor exercises but mainly done on own Drugs – oestrogen in postmenopausal women can help Surgical Aims to support bladder neck to prevent incontinence assoc with increased intraabdo pressure Burch colposuspension – suprapubic non absorbable sutures act as support tissue. Cure rate 80-90%. Can --> voiding difficulty Anterior repair & bladder buttress – similar to burch but performed vaginally, results not as good Tension free vaginal tape (TFVT) – knitted prolene mesh slings behind urethra to support it Suburethral sling – if other surgery failed – slings from abdo wall, around urethra & back again Injections – to bulk up internal sphincter Overactive bladder 2nd commonest cause in adult women – can coexist with enuresis Also known as - Detrusor instability / unstable bladder / hyperactive bladder Urine lost due to involuntary detrusor contraction May be due to neurological problem (eg MS) or bladder neck outlet obstruction Treatment Behavioural therapy – go regularly and then lengthen intervals Drug therapy – anticholinergics (have se of dry mouth, blurred vision, constipation). Drugs include oxybutynin, tolterodine, propiverine & trospium Surgery – involve bladder denervation Fistula Abnormal connection between 2 epithelial surfaces Vesicovaginal & ureterovaginal cause full incontinence Urethrovaginal only causes after micturition Commonest cause is poorly repaired vaginal / gynae surgery/radiotherapy. Can be repaied surgically Retention with overflow Uncommon - Equivalent of man with enlarged prostate Congenital abnormalities Such as ectopic ureter are rare