Stress urinary incontinence, or SUI, is the
involuntary loss of urine with an increase in intra-abdominal pressure, such as coughing,
sneezing, or exercising. SUI is a common and disabling condition affecting up to ⅓ of
women. Two things are necessary for urethral closure
and thus continence, when intra-abdominal pressure increases. First, the pelvic floor musculature and connective
tissue must support the urethra (also known as the bladder neck). When this support fails,
the bladder neck becomes hypermobile, and incontinence occurs. Second, the smooth muscle in the wall of the
urethra must contract like a sphincter. When this fails, urethral closure does not occur.
This is referred to as intrinsic sphincter deficiency. Bladder neck hypermobility is much more common
than is ISD. When assessing a woman with incontinence,
first ensure that the complaint is of stress incontinence, NOT urgency incontinence. The
later implies a different bladder dysfunction. Ask if there are associated symptoms of prolapse,
because the conditions often occur together. Make sure to assess the impact of stress incontinence
on quality of life and on sexual function. SUI is a symptom, not a diagnosis. The symptom
can be confirmed on physical exam by leakage with a cough stress test. Because the usual
mechanism for SUI is hypermobility, the position of the urethra should be assessed on exam.
Pelvic floor muscle tone should also be assessed. Finally, a bimanual exam should be performed
to rule out a pelvic mass as the reason for increased abdominal pressure. The FRED mnemonic provides a helpful initial
approach for the management of SUI: Fluid Restriction;
Pelvic floor Exercises; and Bladder Drill or (timed bladder emptying). Intravaginal pessaries can be tried in patients
who fail conservative management. These provide bracing support under the urethra. If unsuccessful,
referral to a surgeon is next. Sling surgery may be recommended. Like pessaries, slings
work by recreating a stable compressive surface underneath the urethra.