Stress Incontinence

See Also

Epidemiology

More common in younger women
1. Contrast with Urge Incontinence, which is more common in older women
Prevalence: 25-45% of those older than 30 years old

Risk Factors

Bladder neck or Urethral injury
Sphincter weakness from neurologic injury
Medications that relax the Urethral sphincter
1. Example: Alpha-adrenergic Antagonists
2. See Urinary Incontinence due to Medications
Decreased Pelvic Floor Competence
1. Normal aging
2. Surgery
3. Multiparity
4. Postpartum (20-30% at 3 months postpartum)
  1. Glazener (2001) BMJ 323:593-6 [PubMed]

Pathophysiology

Bladder outlet less than intravesicular pressure
Urethral sphincter weakness or Urethral Hypermobility
Weakness of pelvic floor or Bladder neck support
1. Bladder neck descends below pelvic floor on exertion
2. Bladder neck opens
3. Only sphincter (weak) can hold back urine
Triggers (e.g. cough, sneeze) transiently increase intra-abdominal pressure
1. Results in involuntary small-volume leakage of urine

Symptoms

Small amounts of urine lost
1. Contrast with large volumes in Urge Incontinence
Urine loss stops immediately after activity stops
Immediately after increased intrabdominal pressure
1. Cough
2. Sneeze
3. Laugh
4. Heaving or straining

Signs

Leakage after Valsalva or cough with full Bladder
1. See Cough Stress Test
2. See Bladder Stress Test
Urethral Hypermobility Test
1. Apply to urethra Lidocaine jelly or other lubricant
2. Insert sterile cotton swab via Urethra into Bladder
3. Patient performs Valsalva Maneuver
4. Abnormal if the cotton swab angle change 30 degrees from its resting position
Weakness or protrusion
1. Anterior vaginal wall
2. Urethra
3. Bladder

Diagnostics

Bladder volumes (evaluate for other Incontinence causes)
1. Post-void residual under 50 cc
2. Bladder Capacity under 400 cc

Management
General Measures (most effective)

Pelvic Floor Exercises (highly effective, and the maintay of Stress Incontinence management)
1. Kegal Exercises
2. Vaginal weight training (Vaginal cones)
Physical Therapy
1. Biofeedback (visualize pelvic floor contractions)
  1. Highly effective in elimination of Incontinence
  2. Dumoulin (2004) Obstet Gynecol 104:504-10 [PubMed]
2. Functional electrical stimulation (Home electrode stimulation therapy)
  1. Transvaginal or Transrectal electrode applied via probe
    1. Patient performs at home for 15 minutes twice daily for 2 weeks
    2. Indicated for Stress Incontinence refractory to standard Pelvic Floor Exercises
    3. Especially useful in women who are unable to voluntarily contract pelvic floor Muscles
  2. Extracorporeal magnetic innervation (ExMI)
    1. FDA approved for mild Stress Incontinence in patients who have not undergone Incontinence surgery
    2. Patients sits fully clothed on chair that generates low powered electric field
    3. Performed for 20 minutes, 2-3 times weekly for 6-8 weeks
    4. Gilling (2009) BJU int 103(10): 1386-90 [PubMed]
Vaginal devices
1. General
  1. Indicated in pregnancy, non-surgical patients, or Stress Incontinence patients with refractory course
  2. Most devices (except Urethral plug) work by compressing Bladder neck and Urethra
2. Pessaries
  1. Low cost, safe and immediately effective in Stress Incontinence
  2. Consider in older patients
  3. Risk of vaginal infection or local Trauma
  4. Contraindicated in active pelvic infection, vaginal ulceration, or allergy to materials in Pessary
3. Diaphragms
4. Incontinence tampon
  1. Only available in Europe as of 2013
5. Bladder neck support prosthesis (e.g. Milex)
  1. Used temporarily (e.g. during Exercise)
6. Urethral Occlusion insert (Urethral plugs)
  1. Urethral inserts (5 cm long) used for brief planned activities (e.g. during Exercise)
  2. Risk of Urinary Tract Infection (>30% over 2 years) and migration into Bladder (1%)
Situational
1. Weight loss (in Obesity)
2. Tobacco Cessation
3. Avoid Caffeine
4. Planned fluid intake and timed voiding
5. Constipation Management
6. Eliminate provocative medications (e.g. Diuretics)
7. Use effective collection or absorption products and protective garments
  1. Avoid menstrual pads (more likely to leak and cause skin breakdown)

Management
Medications

General
1. Medications have poor efficacy in Stress Incontinence
  1. General measures (e.g. Pelvic Floor Exercises) are the first-line management of Stress Incontinence
  2. No medication is FDA approved for Stress Incontinence
2. Avoid Anticholinergics (e.g. Oxybutynin)
  1. Not effective in Stress Incontinence (and may worsen symptoms)
Duloxetine (Yentreve, Cymbalta)
1. SNRI that stimulates Urethral sphincter contraction
2. Not FDA approved - but appears effective in some cases
Topical Estrogen
1. Indicated for Postmenopausal Atrophic Vaginitis
2. Greater efficacy seen in Urge Incontinence
3. Estrogen not effective in Stress Incontinence
  1. Fantl (1996) Obstet Gynecol 88:745-9 [PubMed]
Alpha Adrenergic Agonists
1. No strong evidence supporting use
2. Adverse effects include Palpitations, increased Blood Pressure, Headaches
3. Preparations
  1. Phenylpropanolamine
  2. Pseudoephedrine
  3. Phenylephrine
4. Mechanism
  1. Increases Bladder outlet Smooth Muscle tone
Tricyclic Antidepressants or SNRI Medications
1. Indications
  1. Mixed Urge Incontinence and Stress Incontinence (esp. if comorbid depression, anxiety or Neuropathy)
  2. Not indicated in Stress Incontinence alone
2. Examples
  1. Imiprimine (Tricyclic Antidepressant)
  2. Duloxetine (SNRI)
3. Mechanism
  1. Anticholinergic
  2. Direct relaxant of detrussor
  3. Alpha-adrenergic-Bladder outlet tone increased

Management
Minimally-Invasive Procedures

Radiofrequency Denaturation
1. Single-time, office-based procedure in which radiofrequency device inserted into Urethra
2. Delivered energy denatures Collagen and reduces compliance in Bladder neck and proximal Urethra
3. Improvement in up to 50% of patients for as long as 3 years after single procedure
4. Adverse effects: Urinary Tract Infections, Dysuria
5. Lukban (2012) Obstet Gynecol Int 2012:384234 [PubMed]
Collagen injection into periurethral area (e.g. Durasphere Transurethral injection)
1. Effective, but Incontinence may recur with time
2. Indicated for intrinsic sphincter deficiency
3. Improvement in up to 40% following procedure (may require repeat procedures)
4. Evidence is limited to small studies, lower quality
5. Adverse effects: Urinary Tract Infections, Dysuria, Urinary Retention
Intravesical balloon
1. Winkler (2018) Female Pelvic Med Reconstr Surg 24(3):222-31 [PubMed]

Management
Surgical

Pubovaginal Sling: Tension-free vaginal tape (TVT)
1. Urethral sling placed under Local Anesthesia
2. More effective than colposuspension
3. Valpas (2004) Obstet Gynecol 104:42-9 [PubMed]
Midurethral mesh sling procedures
1. Types
  1. Retropubic sling
  2. Single incision sling (mini-sling)
  3. Transobturator sling
2. Complications
  1. Postoperative Groin Pain
    1. Present for up to 6 weeks in 12-16% of transobturator approach patients
    2. Release or removal may be required in some patients if symptoms persist
  2. Mesh exposure
    1. Occurs in 13% retropubic, 10% transobturator, 19% mini-sling
  3. Wound Infection
    1. Occurs in 13% retropubic, 2% transobturator, 1% mini-sling
3. References
  1. Schimpf (2014) Am J Obstet Gynecol 211(1): 71.e1-27 [PubMed]
Urethropexy (or colposuspension)
1. Keyhole, Needle or laparoscopic colposuspension (urethropexy)
2. Retropubic colposuspension or urethropexy (Burch Suspension, Marshall-Krantz Procedure)
  1. Elevate UVJ above pelvic floor
  2. Effective, but Incontinence may recur with time
  3. Indicated in Uterine Prolapse

References