Summary
Stress urinary incontinence (SUI) is a type of urinary incontinence characterized by the leakage of urine following activities that increase intra-abdominal pressure (e.g., coughing or sneezing). It is twice as common in women than men, and prevalence increases with age. The underlying mechanism is an increase in bladder pressure that exceeds sphincter resistance, leading to urine being expelled. SUI in women is caused by a variety of conditions (e.g., pelvic muscle dysfunction and/or weakness, intrinsic sphincter deficiency); in men, it is most common secondary to prostate surgery. SUI manifests with predictable, small-volume urinary leakage, typically with no history of irritative bladder symptoms (e.g., urgency or frequency). A diagnosis of SUI is made after performing an initial evaluation of urinary incontinence, assessing for red flags in urinary incontinence, and performing urinary stress testing. Conservative management of urinary incontinence includes pelvic floor physical therapy, bladder training, lifestyle modifications, management of comorbidities, and incontinence products. Additional management options include vaginal pessary, periurethral bulking agents, and anti-incontinence surgery.
Epidemiology
- Sex: ♀ > ♂ (∼ 2:1)
- Prevalence increases with age. [1]
Epidemiological data refers to the US, unless otherwise specified.
Etiology
-
Pathophysiology: 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
- Multiparity
- 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.”
Clinical features
- Physical activity that causes increased intra-abdominal pressure (e.g., laughing, sneezing, coughing, exercising) leads to leakage of urine.
- Frequent, predictable, small-volume urine losses with no urge to urinate prior to the leakage
- Pelvic examination may show pelvic organ prolapse, cystocele, and/or rectocele. [2]
Diagnosis
Approach [2][3][4]
- Perform an initial evaluation for urinary incontinence including: [2][3]
- Refer to a specialist (e.g., urology or urogynecology) for:
- Red flags in urinary incontinence
- Urethral mobility testing for female patients [2]
- Possible additional testing (e.g., fluoroscopy voiding cystourethrography, urodynamic studies) [4][6]
Urinary stress test [2][3][5]
- Performed for all patients to distinguish SUI from other types of urinary incontinence
- With a full bladder (at least 300 mL), the patient performs the Valsalva maneuver or coughs.
- Urine leakage during increased abdominal pressure confirms the diagnosis of SUI.
Urethral mobility testing [2][3][6]
- An assessment performed for female patients to help determine treatment modality
- The patient lies supine and, during the Valsalva maneuver, the degree of urethral displacement is measured using one of the following : [3]
- Urethral cotton swab test (most common): A cotton swab is placed into the urethra to assess how much the swab moves.
- Visual urethral mobility examination
- Transperineal ultrasound
- Urethral mobility of > 30° from the horizontal plane is associated with a higher degree of success for anti-incontinence surgery. [2]
Differential diagnoses
The differential diagnoses listed here are not exhaustive.
Treatment
Approach [3][4]
- Offer incontinence products to prevent dermatological complications of urinary incontinence.
- Assess for features of urge incontinence; manage as mixed incontinence if present.
- Initiate conservative management.
- Refer to a specialist if:
- Red flags in urinary incontinence are present.
- Symptoms persist. [5][7][8]
- Patients wish to pursue surgery as first-line treatment. [4][9]
- Invasive options to manage SUI include:
- Periurethral bulking agents
- Anti-incontinence surgery
Neuromuscular electrical stimulation can be considered for female patients with SUI; however, there is limited evidence to support its use. [3]
Conservative management
- Conservative management of urinary incontinence is first-line therapy for most patients. [3][4]
- Recommend lifestyle and behavioral modifications (e.g., bladder training, smoking cessation, dietary changes). [3]
- Identify and treat underlying conditions (e.g., pelvic organ prolapse, obesity, genitourinary syndrome of menopause). [3]
- Refer for supervised pelvic floor physical therapy (e.g., Kegel exercises). [3]
- Consider a vaginal pessary. [4]
Treatment of genitourinary syndrome of menopause with topical estrogen may improve urinary incontinence symptoms. [3]
Periurethral bulking agents [3][4]
- Injection of substances into the periurethral tissue to narrow the urethra and increase resistance
- Significantly less effective than surgery and repeat injections are often required
- Consider for patients with:
- Preference for nonsurgical management
- Contraindications to anesthesia or surgery
- Recurrence of symptoms after surgery
- Limited urethral mobility (female patients only) [4]
Anti-incontinence surgery
Surgical management is recommended if there is inadequate improvement with conservative management of urinary incontinence. [4]
Female patients [4][10]
-
Midurethral mesh sling
- Preferred surgical treatment
-
A mesh sling is placed under the urethra and bladder neck to lift, support, and exert pressure on the urethra; the sling may pass:
- Retropubically (tension-free vaginal tape)
- Through the obturator foramen (transobturator tape)
-
Alternatives [4]
- Autologous fascial sling [9]
- Urethropexy (Burch colposuspension): surgical fixation of a displaced urethra and bladder neck to nearby tissue to prevent involuntary urine leakage [4]
Midurethral sling is the most effective treatment for SUI in female patients with urethral mobility > 30°. [4][9]
There is insufficient evidence to recommend either laser surgery or artificial urinary sphincters in female patients with SUI. [3]
Male patients [7][8]
-
Surgery is typically reserved for patients with incontinence that: [8]
- Persists for more than 6–12 months following prostate surgery
- Has not responded to pelvic floor physical therapy
- Options include:
- Artificial urinary sphincter (preferred for severe incontinence) [3]
- Adjustable periurethral balloon [3]
- Male sling [3][7]