Stress Urinary Incontinence Disease Profile
Name
Synonyms
genuine stress incontinence, urethral hypermobility,
General
description
The symptom includes involuntary loss of urine during physical
exertion with increased intrabdominal pressure, such as with coughing,
sneezing, laughing, exercise, lifting or sitting.
The urine loss is usually not a large amount but the frequency
with which it occurs may require wearing a pad constantly to
avoid embarassment.
Is it common?
Urinary incontinence has been reported to affect 35% of
American women over 50 years of age an almost 15% who have leakage on a daily basis.
Approximately 60% of women with incontinence will have stress incontinence.
Differentiating
features
When lying down with legs apart, coughing produces a visible
spurt of urine from the urethra. Standing up, with one leg on a
stool and holding a paper towel over the perineum and coughing
produces a wet stain on the paper towel.
A cotton-tipped stick lubricated with xylocaine gel is placed
into the urethra up to, but not through the internal urethral
sphincter (Q-tip test). With straining or coughing, the stick
rises more than 30 degrees from it's resting angle. This
demonstrates urethral hypermobility and differentiates genuine
stress incontinence from an intrinsic urethral sphincteric
insufficiency (ISD) without hypermobility.
Under urodynamic testing, the demonstration of the loss of
urine when the intravesical pressure exceeds the maximum urethral
pressure in the absence of a detrusor contraction.
On static urethral pressure profile, a maximum uretral pressure of
greater than 20 cm of water rules out intrinsic urethral
sphincteric insuficiency (ISD). On stress urethral pressure
profile, a negative urethral differential pressure along the
length of the urethra is confirmatory of stress incontinence.
Other features
Urgency can also be associated with stress incontinence and is
not specific to urge incontinence. 75% of women with
genuine stress incontinence will also report that they experience
urge incontinence. 50% of women with pure detrusor instability report
some of their incontinence is precipitated by stress.
A cystometrogram showing no inhibited bladder contractions and a
maximum cystometric capacity or more than 150 ccs (about 5 oz.)
will rule out mixed urge and stress incontinence.
A post void
residual urine of less than 200 ccs (about 7 oz.) helps to
exclude an associated overflow incontinence.
Usually there is a history of vaginal childbirth.
Symptom onset is gradual over time.
Cause
The theories:
-
Traditionally, genuine stress incontinence (GSI) has been viewed
as an only an anatomic defect. It is thought that if the
bladder and upper portion of the urethra are inside the abdominal
cavity the a rise in the abdominal cavity should squeeze the
bladder and upper urethra at the same time therefore preventing
urine from escaping the bladder. If the upper urethra is not in
the abdominal cavity because the muscles or fascia of the pelvic
floor are stretched or loose, the urethra gets displaced from its
normal intrapelvic location and descends outside of the abdominal
cavity. As a result, as the pressure increases in the abdominal
cavity during stress (like a cough) the upper part of the urethra
is not closed off and the increased pressure in the bladder
allows for leakage outside the body.
- Recent studies have demonstrated a neurophysiological and
histochemical evidence of denervation injury in subjects with
GSI. Usually this is related to trauma from vaginal delivery of
a child, repeated descent of the pelvic floor from chronic
coughing, or straining from lifting or constipation.
- There may be a connection with the pressure changes seen on
urodynamics and lateral detachment of the anterior vaginal wall
and endopelvic fascia from the levator ani muscles.
Unnecessary
studies
Complex urodynamic studies are not necessary if there is not
a history of other than mild urgency symptoms, the Q-tip test shows
hypermobility, the postvoid residual urine is less than 200 ccs,
the maximum bladder capacity is more than 150 ccs, there is no
history of a previous bladder repair surgery and there is no history of
any neurologic or spinal cord disease or trauma.
Natural history
untreated
If untreated, it usually slowly progresses over the years
sometimes with a more rapid worsening right after menopause.
Urinary loss episodes are more frequent urine which may be
socially or hygenically unexceptable to the patient. Almost
constant urine loss significantly irritates the perineal skin.
Goals of
therapy
(Rx)
To stop or minimize the amount of involuntary urine loss
1st choice therapy
Depends on the level of distress caused by the symptoms. All may
be first line therapy
-
Use of pads or diapers as needed during other treatment.
-
Physical therapy to strengthen the external urethral
sphincter such as: Kegel exercises, weighted vaginal cones,
pelvic floor microstimulation therapy and bladder retraining
therapy.
-
Vaginal pessary use which elevates the urethral vesical angle.
- Medical management includes estrogen, phenylpropanolamine (PPA),
combined estrogen and PPA, and discontinuance of any
antihypertensive medications that are basically alpha receptor
antagonists.
-
Surgical: Burch, MMK or needle-based retropubic urethropexy,
sling procedures
Other therapies used
See above
Treatments to
avoid
Avoid:
medications that may promote detrusor contractions such as:
bethanechol, prostaglandins, excessive diuretic use or caffeine
agents that promote relaxation of
the urethra include: alpha receptor blockers, phenoxybenzamine, phentolamine, prazosin,
benzodiazapines (diazepam), progesterone, dantrolene
Reason for Rx
choices
These treatments depend on the level of distress the loss of urine is
causing, as well as the lifestyle modification needed to adjust
to the symptoms. A trial of some form of physical therapy is
used mostly for premenopausal women or women with milder
symptoms. Bladder retraining is useful for all patients.
Pessaries are useful for women who have decreased physical
activity due to age or medical problems or who have to put off
surgery for other reasons. Removal of medical therapy that causes
or aggravates stree incontinence is useful in all patients.
References
Thom D
Variation in estimates of urinary incontinence prevalence in the community: effects of differences in definition, population characteristics, and study type.
J Am Geriatr Soc 1998 Apr;46(4):473-480
NIH Consensus Development Panel, Rowe JW, chairperson, Urinary incontinence
in adults.
JAMA 1989;261: 2685-90
Berghmans LC, Hendriks HJ, Bo K, Hay-Smith EJ, de Bie RA, van Waalwijk van Doorn ES
Conservative treatment of stress urinary incontinence in women: a systematic review of randomized clinical trials.
Br J Urol 1998 Aug;82(2):181-191
Videla FL, Wall LL
Stress incontinence diagnosed without multichannel urodynamic studies.
Obstet Gynecol 1998 Jun;91(6):965-968
Other resources
National Association for Incontinence
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