Disorders of the pelvic floor
(Relaxation of Pelvic Supports and Urogynecology)
Zhou Jianhong
I INTRODUCTION
A Epidemiology
1. Urinary incontinence affects women five times more often than men.
It affects well
over 13 million people in the USA. Despite its prevalence and estimated costs in
excess of $15 billion annually, most women do not seek help for incontinence,
primarily because of social embarrassment or because they are unaware that help is
available.
2. From 10% to 25% of women 25 to 64 years of age and as many as 40% of women
older than 65 years of age suffer from some form of urinary incontinence.
3. As many as 50% of all parous women have pelvic support defects, and 10% to 20%
seek care for pelvic organ prolapse (POP).
4. In the United States, women have a lifetime risk of urinary incontinence or POP that
requires surgical treatment of approximately 10%.
5. The true prevalence of fecal incontinence is unknown, but the disorder is estimated to
affect as many as 10% of women older than 64 years of age.
6. Thirty percent of women with urinary incontinence also have fecal incontinence.
B Anatomy of the pelvic floor. The pelvic organs rest on the pelvic floor muscles and are
held in place with the help of the endopelvic fascia.
1. The pelvic floor is made up of the levator ani and coccygeus muscles. The levator ani
has three parts, including the puborectalis and pubococcygeus (also referred to as the
pubovisceral muscle) and iliococcygeus muscles.
2. Endopelvic fascia is a loose network of connective tissue, small vessels, lymphatics,
and nerves, which surrounds and supports the pelvic organs and the vagina.
Thickenings of the endopelvic fascia are known as ligaments (e.g., the uterosacral and
cardinal ligaments, rectovaginal and vesicovaginal fascia).
3. The vagina is attached at three levels. The apex is supported by the cardinal and
uterosacral ligaments. The midvagina is supported by the attachment of the vagina to
the levator ani at the arcus tendineus fascia pelvis (white line). The lower vagina is
supported by its attachment to the perineal membrane and the perineal body. Normal
vaginal attachments help to keep the pelvic organs (i.e., the uterus, bladder, and
rectum) in place.
C Innervation of the pelvic floor and its functions
1. The levator ani is innervated by sacral nerve roots (S2 to S4). This muscle group is
tonically stimulated to contract, providing constant support to the pelvic organs.
2. Bladder filling and voiding functions are controlled by closely coordinated autonomic
and somatic pathways.
a. Autonomic nervous system
(1) Sympathetic (thoracolumbar) nerves promote urine storage by relaxing the
II
bladder (detrusor) muscle and contracting smooth muscle in the bladder neck
and urethra. These nerves are inhibited during voiding.
(2) Parasympathetic (sacral) nerves cause the detrusor muscle to contract. They are
stimulated during micturition.
b. The somatic nervous system controls the striated external urethral sphincter and
levator ani muscle through the pudendal nerve and the sacral nerve roots (S2 to S4).
Inhibition of these nerves causes relaxation of the bladder outlet and pelvic floor,
which must occur during voiding.
c. The central nervous system (CNS) provides voluntary control and modification of
micturition and defecation reflexes.
PELVIC ORGAN PROLAPSE (also called pelvic relaxation)
Such prolapse or protrusion of pelvic structures into the vaginal canal results from
weakening or damage to pelvic support structures.
A Risk factors
1. Vaginal childbirth may damage or weaken pelvic support structures. This damage
may be direct injury to the muscle and fascia of the pelvis or indirect weakness of
the muscles caused by neurologic injury.
2. Obesity, chronic cough, and chronic constipation may cause increased
intra-abdominal pressures, increasing the risk of POP.
3. Increasing age is associated with an increased risk of POP.
4. A genetic predisposition for POP may exist in some women.
B Terminology
1. Cystocele is protrusion of the bladder behind the anterior vaginal wall. This
represents failure of support at the midvagina anteriorly.
2. Uterine prolapse is descent of the uterus into the lower part of the vagina or through
the vaginal opening.
3. Vaginal vault prolapse is descent of the vaginal apex after hysterectomy. Uterine
prolapse and vaginal prolapse represent failure of apical support of the vagina.
4. Enterocele is protrusion of small bowel behind the upper vaginal wall into the
vaginal canal.
5. Rectocele is protrusion of the rectum behind the posterior vaginal wall. This
represents failure of midvaginal support posteriorly.
6. Relaxed or widened vaginal outlet. This represents failure of support of the lower
vagina.
C Symptoms. Mild forms of POP are often asymptomatic. Advanced forms of POP may
cause difficulty with urination or defecation. Associated symptoms may include:
1. Bulge of tissue protruding through the vaginal opening
2. Pelvic or vaginal pressure, especially after prolonged standing
3. Dyspareunia
D Evaluation
1. Prolapse is diagnosed on pelvic examination, performed in the lithotomy and
standing positions.
2. The severity of prolapse may be classified according to systems that describe the
location and severity of POP.
a. Halfway system
b. Pelvic Organ Prolapse Quantification (POP-Q)
E Treatment. Asymptomatic POP does not require treatment.
1. Pelvic floor muscle (Kegel) exercises may improve symptoms caused by mild forms
of prolapse.
2. Pessaries are devices placed in the vagina that support prolapse.
3. Surgery for POP aims to relieve symptoms and to restore normal anatomic
relationships. The surgical procedure and approach (abdominal or vaginal) is tailored
to the particular type of POP present.
a. Hysterectomy for uterine prolapse
b. Anterior repair, paravaginal repair for cystocele
c. Posterior repair for rectocele
d. Enterocele repair
e. Vaginal vault suspension (sacrospinous suspension)
f. Perineorrhaphy for relaxed vaginal outlet.
III URINARY INCONTINENCE
A Types
1. Stress urinary incontinence (SUI) is the loss of urine that occurs with increased
abdominal pressure, such as coughing or straining. SUI is the result of loss of
anatomic support of the urethrovesical junction or urethra. It most commonly occurs
following pelvic floor muscle and nerve damage that resulted from childbearing.
a. Urethral hypermobility is the most common form of SUI and usually follows child
birth injury to urethral support. The SUI occurs because the urethra can no longer
be compressed against the vagina during raised intra-abdominal pressure.
b. Intrinsic urethral sphincteric deficiency is less common and is caused by a
weakened urethral sphincter. Severe SUI develops even with minimal exertion.
Risk factors are scarification from prior anti-incontinence surgery and aging.
2. Urge incontinence is defined by the symptom of urine loss that occurs when the
patient experiences urgency, or a strong desire to void. This type of incontinence is
often accompanied by symptoms of urinary frequency, urgency, and nocturia. Urge
incontinence includes the following subtypes:
a. Detrusor overactivity (DO) (previously called detrusor instability), or overactive
bladder, is caused by involuntary detrusor contractions. Its cause is usually
unknown.
b. Neurogenic DO is involuntary detrusor contractions associated with a neurologic
disorder (e.g., stroke, spinal cord injury, or multiple sclerosis). It is a common
cause of incontinence in elderly and institutionalized women.
3. Mixed incontinence occurs when both stress and detrusor instability occur
simultaneously. Patients may present with symptoms of both types of
incontinence.
4. Overflow incontinence occurs because of underactivity of the detrusor muscle. This
form of incontinence is associated with retention of urine. The bladder does not
empty completely, and “dribbling” of urine occurs.
5. Extraurethral sources of urine include genitourinary fistulas, which may be congenital
or follow pelvic surgery or radiation. These typically cause continuous leaking of
urine.
B Evaluation
1. A detailed history is essential and should include:
a. Urinary symptoms, including the presence of voiding frequency, nocturia, urgency,
precipitating events, and frequency of loss. A voiding diary allows the patient to
document voiding frequency and incontinence episodes during a specific period.
b. Previous urologic surgery
c. Obstetric history, including parity, birth weights, and mode of delivery
d. CNS or spinal cord disorders
e. Use of medications, including diuretics, antihypertensives, caffeine, alcohol,
anticholinergics, decongestants, nicotine, and psychotropics
f. Presence of other medical disorders (e.g., hypertension or hematuria)
2. Physical examination may detect:
a. Exacerbating conditions, such as chronic obstructive pulmonary disease, obesity, or
intra-abdominal mass
b. Hypermobility of the urethra
c. POP
d. Neurologic disorders
3. Diagnostic tests
a. A midstream urine specimen is collected for urinalysis or culture and sensitivity.
Infection may aggravate urinary incontinence.
b. Postvoid residual urine volume should be measured (by ultrasound or
catheterization) after the patient has voided. Typically, the postvoid residual
urine volume is less than 50 to 100 ml.
c. The Q-tip test is an indirect measure of the urethral axis. A Q-tip is inserted into the
urethra with the patient in the lithotomy position. If the Q-tip moves more than
30 degrees from the horizontal with straining, urethra hypermobility is present.
d. Urodynamic testing, including a cystometrogram and voiding studies, may be
useful for demonstrating the type of incontinence present. These tests measure
pressures within the bladder and abdomen during bladder filling and emptying.
Urodynamic testing is indicated for complex cases of urinary incontinence such
as mixed incontinence (presence of two or more kinds of incontinence in the
same patient) or in patients with incontinence and retention of urine.
4. Cystoscopy is performed in some patients to examine the bladder and urethral
mucosa for abnormalities such as diverticula or neoplasms.
C Treatment. Therapy depends on the underlying diagnosis.
1. Treatment of exacerbating factors such as excess weight, chronic cough, or
constipation may improve SUI.
2. Pelvic muscle rehabilitation may be helpful for both SUI and DO.
a. Kegel exercises
b. Vaginal cones
c. Biofeedback
d. Electrical stimulation
IV
3. Pessaries, other intravaginal devices, and urethral plugs and inserts are useful
conservative therapies for SUI.
4. Drug therapy is the mainstay of treatment for DO but is of limited value in treating
SUI.
a. Antispasmodic agents (oxybutynin and tolterodine) are highly effective and are the
most commonly prescribed treatments for DO. However, they cause side effects,
such as dry mouth and constipation, in about 25% of patients.
b. α-Adrenergic stimulating agents (e.g., pseudoephedrine, imipramine) increase
smooth muscle contraction in the urethral sphincter and may decrease SUI
symptoms.
c. Estrogens (systemic or vaginal) improve irritative bladder symptoms such as
urgency and dysuria in postmenopausal women but do not significantly improve
urinary leakage. Hormone replacement therapy does not reduce the incidence of
urinary symptoms in postmenopausal women.
5. Surgery is extremely effective in the treatment of SUI. It is rarely helpful for DO and
is generally reserved only for intractable cases.
a. Injection of bulking agents around the urethra is a minimally invasive procedure
to treat SUI resulting from intrinsic urethral sphincteric deficiency. Collagen, the
bulking agent currently used most commonly, provides a temporary (3 to 12
months) cure or improvement rates ranging from 50% to 70%. They are generally
indicated for patients unable to tolerate major surgery.
b. Retropubic urethropexy elevates the urethra and bladder neck by fixing the
paraurethral connective tissues to the pubis. The most common type of retropubic
operation performed is the Burch procedure, which suspends the vaginal fascia
lateral to the iliopectineal line (Cooper ligament). Burch procedure are most
successful in patients who have SUI associated with urethral hypermobility,
resulting in long-term cure rates of 75% to 90%. Postoperative complications are
uncommon but may include urinary retention and new DO. The procedures may
be performed via an abdominal incision or laparoscopically.
c. Transvaginal needle procedures stabilize the bladder neck by anchoring vaginal
tissue to the rectus fascia or symphysis pubis. These procedures have lower
long-term cure rates than retropubic operations and suburethral slings and now
not generally performed.
d. Suburethral sling procedures, which place various biologic and synthetic
materials under the urethra, appear to affect treatment by partially obstructing the
urethra during times of increased intra-abdominal pressure. Sling procedures
differ according to the type of material and the sling fixation points used; however,
they all have high cure rates (80% to 90%). Sling procedures are more effective
than retropubic operations in patients with intrinsic urethral sphincteric deficiency.
Complications of sling procedures may include infection and ulceration
(especially with the use of synthetic grafts) and urinary retention.
FECAL INCONTINENCE
The involuntary loss of stool or gas is a socially embarrassing disorder. Symptoms of fecal
incontinence are often not reported to physicians.
A. Pathophysiology
1. Fecal continence depends on stool consistency and volume, colonic transit time,
rectal compliance, and innervation and function of the anal sphincter and pelvic
floor.
2. Gastrointestinal and neurologic disorders may result in fecal incontinence.
3. Obstetric injuries to the pelvic floor, as well as denervation injuries related to
childbirth or chronic straining, are the most common cause of fecal incontinence
in women.
B. Symptoms
1. Fecal urgency
2. Incontinence of flatus
3. Incontinence of stool
C. Evaluation. A detailed history and examination, including a vaginal and rectal
examination, are essential. Useful test for determining the etiology of fecal
incontinence may include anal ultrasound, anal manometry, and pelvic floor nerve
conductance studies.
D. Treatment. Therapy may include behavioral modification, pharmacologic agents,
biofeedback, and surgery.