Stress Urinary Incontinence
Urinary incontinence (UI) is defined by the International Continence Society
(ICS) as a complaint of any involuntary leakage of urine and is objectively
demonstrable. This definition covers various aspects of incontinence,
including symptoms, physical sigs which are most relevant to clinicians, the
urodynamic observation as studied by urodynamicists, and the condition as a
whole.
In stress urinary incontinence (SUI), the symptom is the complaint of
involuntary leakage on exertion or on sneezing or coughing. The sign is the
observation of involuntary urinary loss from the urethra synchronous with
exertion, sneezing, or coughing, while urodynamic stress incontinence is
noted during urodynamic testing (filling cystometry) and is defined as the
involuntary leakage of urine during increases in abdominal pressure in the
absence of detrusor contraction.
In urge urinary incontinence (UUI) the symptom is the complaint of an
involuntary leakage accompanied by or immediately preceded by urgency.
The sign is the observation of involuntary urinary loss from the urethra that
is accompanied by or immediately preceded by urgency.
Mixed urinary incontinence (MUI) is the complaint of an involuntary
leakage of urine associated with urgency and also with exertion, effort,
sneezing, or coughing.
Urinary incontinence is more prevalent in women than in men, making
gender itself a risk factor. Its prevalence ranged from 5% to 72% among
women. Incontinence during pregnancy has a prevalence of 31% to 60%, but
it resolves in most cases .
Several large surveys reported the relative proportions of SUI, MUI and
UUI. The Norwegian EPINCONT study (epidemiology of urinary
incontinence) revealed SUI in 50% of incontinent women, UUI in 11% and
MUI in 36%. SUI was bothersome in 17% to 24% of incontinent women .
Several risk factors for developing SUI in women have been suggested
including weak collagen, age, childbearing, obesity, constipation, advanced
pelvic organ prolapse and chronic obstructive airways disease.
The data derived from the EPINCONT study clearly show the impact of age
on the prevalence of UI. This large survey of > 27 000 community-dwelling
female respondents, covering the whole adult age range, showed increasing
UI prevalence rates with increasing age. There was an early prevalence peak
in midlife at about the time of the menopause. This prevalence pattern seems
to be related to the change in the type of incontinence that occurs during
adulthood; SUI is most common in younger and middle-aged women,
whereas MUI predominates in older women (7).
Pathophysiologically, SUI is thought to occur as a result of bladder
neck/urethral hypermobility and/or neuromuscular defects (intrinsic
sphincter deficiency). Urine leaks whenever the urethral resistance is
exceeded by an increase in intra-abdominal pressure during effort, exercise,
coughing or sneezing. An accurate diagnosis is important to provide each
patient with the most appropriate treatment option.
Treatment of stress urinary incontinence starts with conservative therapy
which is considered as the first-line therapy for SUI, especially in less severe
conditions.
Starting with lifestyle interventions as reduction of body weight, stopping
smoking, and fluid management (restriction of fluid intake) .
These are often recommended as supportive measures, to prevent further
aggravation of SUI.
Pelvic floor muscle training (PFMT) is the most commonly recommended
conservative therapy for women with SUI.
PFMT is used to rehabilitate or strengthen the pelvic floor muscles (PFM), it
increases the ability to produce an increase in urethral resistance, provided
the patient is able to perform a correct voluntary PFM contraction. It
counteracts PFM weakness, increasing support for the urethra and bladder,
and improves the tone of the PFM - in particular the levator ani.
A patient-specific regimen should be established, depending on the status of
the muscles. PFMT includes long, slow contractions at regular intervals. The
major drawback on this type of treatment is the compliance, which is usually
high upon initiation, but decreases over time.
Combined therapy of PFMT and adjuncts like vaginal cones, biofeedback
and electrical stimulation seems to have no additional benefit over PFMT
alone, but may be useful for some women to learn how to perform a correct
PFM contraction.
Regarding pharmacological treatment; various drugs are available for
women with SUI including oestrogens, adrenoceptor
agonists, tricyclic
antidepressants (TCAs) and duloxetine have been tried for the treatment of
SUI . However, there is limited or no evidence of the efficacy of these drugs,
and some are associated with significant side-effects.
Patients in whom conservative or pharmacological treatments are not
successful or who have severe SUI can choose surgery to improve their
condition.
Surgical options can be classified into four categories: retropubic
suspension, transvaginal suspension, anterior repair, and sling procedures.
Retropubic suspension as that described by Burch in 1961, using Cooper’s
ligament as an anchor for sutures that include the periurethral and perivesical
tissues. Transvaginal suspension described by Peyera and modified by Raz
in 1981 uses vaginal incisions to place sutures that passed upward and
secured to the abdominal fascia .
Since the beginning of 20th century, sling procedures have been used for
treatment of female SUI. At the beginning of the 20 th century, VonGiordano
described the first urethral sling that used gracilis muscle. Modifications to
the technique were subsequently described, that predominantly used other
muscle bodies, such as pyramidalis muscle flap and plication of the
perivesical muscular structures. Common to these techniques was the belief
that muscle placed around the bladder neck would provide a sphincteric
function.
As sling techniques evolved, a variety of materials came into use. Price
described the first fascia lata sling in 1933. The origin of the contemporary
pubovaginal sling may be found in the classic technique described by
Aldridge in 1942, in which a strip of rectus fascia was secured beneath the
urethra to provide increased resistance at times of heightened abdominal
pressures. This technique was later modified to leave the external oblique
aponeurosis attached to the pubic tubercle and suture the fascial ends
beneath the proximal urethra.
This era of sling development was also notable for the popularity of
abdominal retropubic and transvaginal suspension procedures, characterized
by techniques to suspend the bladder neck by fixation of surrounding tissues.
Accordingly, in 1949, Marshall et al, pioneered a technique for bladder-neck
suspension through the fixation of perivesical bladder-neck tissue to the
pubic symphysis. Rare but severe bony complications were attributed to
pubic symphyseal fixation, however, and consequently Burch described a
modified retropubic suspension in which the fixation point was positioned
laterally along Cooper's ligament .
Although satisfactory continence rates were achieved by retropubic
procedures, the invasive nature of the abdominal approach and consequently
long durations of hospital stay and postoperative convalescence rendered
them less ideal than the vaginal approach. Additionally, perioperative
morbidity was notable.
In recent years, the emphasis has shifted toward minimally invasive
procedures because of the recognized benefits of rapid recovery and return
to work, minimal morbidity, and decreased cost. The tension-free vaginal
tape (TVT) procedure, developed by Ulf Ulmsten in the early 1990s, is very
similar to the traditional pubovaginal sling procedure. The TVT procedure is
performed with a prepackaged kit that permits the surgeon to use very small
incisions, resulting in minimal discomfort to the woman and a rapid
recovery. This technical update will address the place of the TVT procedure
in the management of stress incontinence.
The SPMUS system differs from TVT, in that the needles are thinner and
pass in an antegrade fashion from 2 small suprapubic incisions allowing
added control of the needles’ path compared to the TVT technique.