Urinary incontinence

Urge incontinence - involuntary leakage, immediately preceded by urgency - often overactive bladder or bladder neuropathy.

Stress incontinence - involuntary leakage which occurs when intra-abdominal pressure rises.

Incidence

• 5% men, 20% of women lifetime incidence
• 40% of women >60yo
• 50% of institutionalised elderly patients

Aetiology

• Children - often a/w
  • Infections
  • Constipation
  • Psychological factors
  • Intentional misconduct
  • Increased fluid intake
  • Overactive bladder
• Problems of social control
  • Seen in dementia patients - uninhibited detrusor hyperreflexia and impaired social perception
• Storage problems
  • Small bladder capacity owing to fibrosis (TB, RTx, interstitial cystitis)
  • Small functional capacity owing to severe detrusor instability, neurogenic dysfunction or infection
• Impairment of emptying
  • Small functional bladder capacities with detrusor overactivity causing incontinence, despite having large residual volumes of urine
• Weak sphincter
  • Leads to genuine stress incontinence
  • Can follow surgical procedures such as radical prostatectomy
• Fistulae

Aetiology by gender

• Men
  • Chronic retention with overflow
    • BPH
    • Prostate cancer
    • Urethral stricture
    • Hypertrophy of bladder neck (younger men)
  • Post-prostatectomy
    • Injury to external sphincter mechanism
      • Pelvic floor exercises
      • Exclude anastomotic stricture
• Women
  • Stress incontinence - usually found in multiparous women with a history of difficult labour
    • Minor symptoms can be controlled by pelvic floor exercises
    • Surgery - colposuspension (sutures are placed between vaginal fascia and iliopubic ligament) or transvaginal tape
• Both genders
  • Idiopathic detrusor overactivity
    • Usually results in frequency, urgency, urge incontinence, noturia or enuresis
    • Distinguish from GSI and BOO
    • Exclude infection, TB and cancer
    • Treat with anticholinergics (oxybutynin)
    • Sometimes need enterocystoplasty or botox injections
  • Ageing
    • Smooth muscle dysfunction - small functional capacity, detrusor overactivity, impaired bladder emptying, LUTS
  • Congenital
    • Ectopic vesicae and severe epispadias
  • Trauma
  • Infection
  • Neoplasia
    • Direct invasion from cervical cancer or prostate cancer to the sphincter

History

• Apart from the obvious
• Constant dribbling coupled with normal micturition could be a ureteric fistula
• Nocturnal enuresis in adolescents - primary vs secondary - vast majority eventually get better once secondary causes have been excluded

Investigation

• Frequency voiding charts
• Urodynamic testing
  • Artificially simulate bladder filling and emptying while taking pressure measurements
  • Indications:
    • Distinguishing stress incontinence from detrusor instability in women
    • Classification of neurogenic bladder dysfunction
    • Distinguish bladder outflow obstruction from idiopathic detrusor instability in men
    • Low threshold in general for use in investigating incontinence or LUTS
  • Overactive bladder
    • Phasic increases in pressure give rise to urgency and urge incontinence
    • Found in patients with neurogenic bladder dysfunction, such as MS or PD, or after a stroke or spinal cord injury
    • 50% of men with BOO have detrusor instability, and in about half of them the problem resolves after prostatectomy
  • Genuine stress incontinence
    • Leakage due to increased abdominal pressure, not just increased true detrusor pressure
    • Caused by sphincter weakness
  • Chronic urinary retention
    • Incontinence is secondary to overflow, with large residual volume
  • Bladder outflow obstruction
    • Increased voiding pressures, often in excess of 90cm H2O, coupled with low urinary flow rates
• Urine MCS
• Creatinine

Treatment

• Conservative - pelvic floor physio, bladder training, lifestyle
• Devices for collection - condom catheter, ISC
• Drugs
  • Adrenergic blockers decrease strength of bladder neck
  • Inhibit bladder activity - anticholinergics
• Increasing outlet - resistance colposuspension or TVT or slings, periurethral injections of bulking agents, artificial urinary sphincter
• Denervation of bladder - S3 blockade - rarely used nowadays
• Sacral nerve stimulation devices
• Augmentation of bladder
• Urinary diversion - ileal conduit, continent urinary diversion