Stress incontinence

Stress incontinence is the involuntary leakage of urine following any activity associated with raised intra-abdominal pressure (e.g., coughing, sneezing). It is twice as common in women than in men and its prevalence increases with age. Stress incontinence can be caused by a variety of conditions (e.g., pelvic floor weakness, intrinsic sphincter deficiency, etc.), the underlying mechanism of which is an increase in bladder pressure that exceeds sphincter resistance, which leads to expelling of urine. Individuals with the condition have predictable, small-volume urinary loss, typically during physical exertion, with no history of irritative symptoms of the bladder (urgency or frequency). Diagnosis is based on physical examination, a detailed medical history, and imaging studies. Treatment usually consists of leakage management measures (diapers, catheterization, etc.), drugs (anticholinergics), and in severe cases, surgery (sling operations, taping, etc.).

• Sex: ♀ > ♂ (∼ 2:1)
• Prevalence increases with age. ^[1]

Epidemiological data refers to the US, unless otherwise specified.

• Pathomechanism: outlet incompetence
  • Urethral hypermobility: loss of pelvic floor musculature and/or connective tissue support → weak pelvic floor → inability of the urethra to completely close
  • Intrinsic sphincter deficiency
• Risk factors
  • Multipara
  • Pregnancy and vaginal deliveries
  • High-impact activity (e.g., jumping, running, hopping)
  • Menopause
  • Obesity
  • Smoking
  • Chronic cough (e.g., COPD)
  • Prostate or pelvic surgery
• See “Etiology” in “Urinary incontinence.”

• Physical activity that causes increased intra-abdominal pressure (e.g., laughing, sneezing, coughing, exercising) leads to loss of urine
• Frequent, predictable, small-volume urine losses with no urge to urinate prior to the leakage

• See “Diagnostics for urinary incontinence.“
• Urinary stress test: Leakage of urine under conditions that cause increased abdominal pressure (e.g., Valsalva maneuver, forced coughing) is a sign of stress incontinence.
• Marshall test (only for women)
  • Conducted by elevating the urethra and bladder neck
  • The patient is asked to cough. When urine is released, the urethra is elevated with a clamp or fingers are inserted into the vagina.
  • The Marshall test is positive if no urine is released on renewed coughing, which confirms the diagnosis.
• Vaginal and rectal examination: to exclude a cystocele and/or rectocele. ^[2]

• Urge incontinence
• Mixed incontinence
• Overflow incontinence
• Total incontinence

The differential diagnoses listed here are not exhaustive.

Conservative treatment

• See “General principles of treatment of urinary incontinence.”
• Kegel exercises
• Lifestyle changes (e.g., weight loss, avoiding alcohol and caffeine, smoking cessation)
• Vaginal pessary
• Possible pharmacotherapy
  • Duloxetine: to enhance sphincter contraction
  • Anticholinergic drugs can be used, but they tend to only be effective in mild cases of stress incontinence.

Surgical procedures

• Indicated if conservative treatment does not provide sufficient improvement of symptoms
• Procedure of choice: midurethral sling to elevate the urethra
• Alternative: urethropexy
  • Surgical fixation of a displaced urethra and bladder neck to nearby tissue to prevent involuntary urine leakage
  • Formerly the gold standard (before the introduction of midurethral slings) but now used less because it requires laparotomy or laparoscopy and is associated with more complications
  • Mainly reserved for patients who also require repair of pelvic organ prolapse
• Less common alternatives
  • Periurethral bulking therapy
  • Artificial urinary sphincter placement
  • Bladder neck suspension
    • Tension-free vaginal tape (TVT)
    • Transobturator tape (TOT)