Incontinence of
urine
Normal urinary continence is dependent on
several factors. These include normal mobility and normal brain function
allowing a perception of when it is socially acceptable to void, normal bladder
sensation, normal voluntary detrusor contraction producing good bladder
emptying, a normally competent sphincter mechanism which relaxes appropriately
during a voluntary detrusor contraction allowing good bladder emptying and
good bladder capacity with normally low pressures during filling. This is
clearly a fine balance and several factors can cause incontinence.
In
the diagnosis of urinary incontinence, a careful history and physical
examination may help, but it will be necessary to carry out urodynamic testing
in most patients if surgical intervention is proposed. The urine should be
cultured to exclude infection and the serum creatinine should be measured. It
may be appropriate to have anatomical visualisation of the urinary tract by
means of IVU if one suspects a ureteric fistula, although ultrasound examination
will often provide adequate details.
Urodynamic
testing
The key to the practical management of lower
urinary tract dysfunction lies with urodynamic investigation. The principle is
artificially to simulate bladder filling and emptying whilst obtaining pressure
measurements (Fig. 65.14).
The
patient attends with a full bladder and is allowed to void in private to measure
maximum urinary flow rate. After voiding, the residual urine is measured by
means of ultrasound to assess the completeness of bladder emptying. Urodynamic
testing involves the aseptic passage of a small pair of catheters or a
twin-lumen catheter into the bladder; this allows the bladder to be filled with
saline or contrast medium at a rate of 50 mI/minute whilst a continuous
recording of the intravesical
Usefulness of urodynamic testing
•
Distinguishing genuine stress incontinence (due to sphincter weakness)
from detrusor instability in women (Fig. 65.15)
•
Classification of neurogenic bladder dysfunction
•
Distinguishing bladder outflow obstruction from idiopathic detrusor
instability in men
•
Investigation of incontinence
The
normal bladder will accept approximately 400—55
0 ml when filled with saline at room temperature at filling rates of 50
ml/minute. The pressure increase in the bladder should be less than 15 cmH2O.
In addition, phasic pressure increases should not be seen. The normal voiding
pressure should not exceed 60 cmH2O in men and about 40 cmH2O
in women, with a flow rate of between 20 and 25 mI/second.
Common
abnormalities identified during urodynamic testing in incontinence
•
Phasic increases giving rise to sensations of urgency of micturition
and urge incontinence (detrusor instability; Fig. 65.16).
This abnormality is found in patients with several types of neurogenic
bladder dysfunction such as multiple sclerosis (MS), Parkinson’s disease, or
following a stroke or certain types of spinal injury when it is known as
detrusor hyperreflexia. In addition, about 50 per cent of men with bladder
outflow obstruction have detrusor instability, and in about half of these men
the instability resolves after prostatectomy. Idiopathic detrusor instability is
common and must be distinguished from genuine stress incontinence in women
before performing bladder neck suspension procedures.
•
Genuine stress incontinence is defined as urinary leakage occurring
during increased bladder pressure when this is solely due to increased abdominal
pressure and not due to increased true detrusor pressure (Fig. 65.15).
It is caused by sphincter weakness.
•
Chronic urinary retention with overflow incontinence. This is recognised
by a large residual volume of urine (Fig. 65.17) and is usually associated with
high pressures during bladder filling.
•
Bladder outflow obstruction, which is associated with increased voiding
pressures often being in excess of 90 cmH2O (Fig.
65.18), coupled
with low urinary flow rates.
• Neurogenic bladder dysfunction.
Causes of
incontinence
There are various ways of classifying causes
of incontinence. A good functional method is as follows.
• Problems of social control — patients with Alzheimer ‘s disease,
Parkinson’s disease or multi-infarct dementia often have urinary incontinence
owing to a combination of uninhibited detrusor hyperreflexia and impaired social
perception.
• Storage problems — patients with a small capacity owing to fibrosis
from tuberculosis or interstitial cystitis can develop incontinence. Patients
with a small functional capacity owing to severe idiopathic detrusor
instability, neurogenic bladder dysfunction or urinary infection also can
develop incontinence.
• Severe impairment of emptying — patients with chronic retention or some
types of neurogenic bladder dysfunction often have small functional bladder capacities with detrusor overactivity causing
incontinence, despite having large residual volumes of urine.
• Weak sphincter — patients with genuine stress incontinence owing to previous
prolonged labour or with damage to the distal sphincter mechanism secondary to
prostatectomy or
with neurogenic bladder dysfunction often have impaired sphincter
function which leads to stress incontinence. Congenital causes such as
epispadias also result in sphincter weakness.
• Fistulae — leakage from fistulae or upper tract duplication with an ectopic
ureter.
The
common causes may be classified into male, female or mixed sex groups.
Male
Chronic urinary retention with overflow. This
is a common cause of incontinence and may be due to benign prostatic
hypertrophy, carcinoma of the prostate, urethral stricture and, in younger men,
hypertrophy of the bladder neck. The key to the diagnosis lies with the history
of prolonged hesitancy and a poor urinary stream with both daytime and
nocturnal
‘dribbling incontinence’ coupled with the finding of a distended bladder.
Examination may reveal that the bladder is visibly distended, the transverse
suprapubic crease is lost and the painless distension of the bladder may be
palpated or percussed. It may easily be diagnosed by means of ultrasound
measurement of residual urine volume. The treatment is discussed in Chapter 66.
Postprostatectomy.
Postprostatectomy incontinence may result from injury to the external sphincter
mechanism which may be caused by clumsy surgery — urodynamic evaluation will
demonstrate genuine sphincter weakness. The other cause of incontinence is
idiopathic detrusor instability, although such patients often have significant
irritative symptoms prior to prostatectomy and should be identified and
investigated by means of urodynamic studies prior to prostatectomy.
Female
Stress incontinence. The commonest cause of
leakage of urine in women is genuine stress incontinence (GSI), although in some
parts of the world vesicourethral fistulae owing to neglected labour are very
common. GSI occurs secondary to weakness of the distal sphincter mechanism
associated with laxity of the pelvic floor. It is usually found in multiparous
women with a history of difficult labour often accompanied by the use of
forceps. It can be found in normal young women who indulge in competitive
trampolining and also in patients with epispadias. The classical symptoms are
complaints of urine loss during coughing, laughing, sneezing or sudden change of
posture. The symptoms may change with the menstrual cycle. The volume of urine
loss can be measured during an exercise test which is performed by putting the
patient through a standard set of tests with 300 ml of fluid in the bladder; in
GSI the fluid losses usually range from 10 to 50 ml. Urinary frequency and
urgency are, however, often found in such patients as they try to avoid
incontinence by frequent voiding.
Idiopathic
detrusor instability can closely mimic GSI and indeed can coexist with it. It is
important to make a correct
Minor
degrees of stress urinary incontinence often can be controlled by means of
teaching the patient a series of pelvic floor exercises. However, if this fails
then surgery is indicated. The best standard operation is the Butch
colposuspension.
This
operation is carried out with the patient in the Lloyd-Davies position through a
Pfannenstiel incision. The vaginal fascia is identified by sweeping the bladder
off the vagina and three sutures are placed on each side between the vaginal
fascia and the iliopubic ligament. A suprapubic catheter is placed. The
operation corrects minor degrees of cystocoele. Voiding difficulties are
frequent, but usually temporary. It is best to warn women with large bladder
capacities and low voiding pressures that this complication may occur and that
they may require to carry out CISC for a period. The operation is very
successful in the treatment of GSI with 90 per cent 1-year good results, which
are maintained in about 80 pet cent at 5 years.
Endoscopic needle bladder neck suspension can now be carried out, but is less
successful than open operation.
Common to both
sexes
Idiopathic detrusor instability (DI). This
condition is very common. Phasic increases in bladder pressure may occur during
filling in otherwise normal patients (idiopathic) or it may be found in several
conditions including neurogenic bladder dysfunction (then known as detrusor
hyperreflexia) and bladder outflow obstruction. Idiopathic detrusor
instability may be symptomless, but usually results in symptoms of frequency,
urgency, urge incontinence, nocturia or nocturnal incontinence (enuresis)
depending on the severity of the instability. It must be distinguished from GSI
and from bladder outflow obstruction as colposuspension or prostatectomy have
poor results in patients with severe idiopathic DI. Most urologists will want to
exclude infection, tuberculosis or carcinoma in situ by urine culture, cytological examination, cystoscopy and
confirmation of the diagnosis by means of urodynamic investigation. The mainstay
of treatment is the use of various anticholinergic medication (propantheline,
oxybutinine, tolteroclise, and amytryptiline). Severe symptoms resistant to
conventional conservative treatment resulting in major impairment of quality of
life may need more aggressive treatment such as enterocystoplasty.
Ageing.
In both sexes ageing can result in smooth muscle cell dysfunction that can cause
combinations of small functional capacities, detrusor instability, impaired
bladder emptying and symptoms of lower urinary tract dysfunction.
Congenital.
Ectopic vesicae and severe epispadias. The abnormal entry of an ectopic ureter
distal to the sphincter complex or into the vagina in a female should
theoretically result in total urinary incontinence. This is discussed in Chapter
62.
Trauma.
Trauma, whether from pelvic surgery or associated with pelvic fracture, may
result in disruption of the nerve supply to the bladder or urethra or in fistula
formation.
Infection.
Simple lower urinary tract infection may be sufficient, particularly in a woman,
to induce urinary incontinence. A history of frequency, burning and a fever
should prompt the diagnosis. The bladder may be tender whether palpated
suprapubically or
per
vaginum. Symptoms will usually
settle with a course of antibiotics, but in the case of recurrent infection
further investigation of the urinary tract will clearly be indicated.
Neoplasia.
Locally advanced cancers in the pelvis, particularly carcinoma of the cervix
in a woman and prostate in a man, may result in direct invasion of the sphincter
mechanism causing incontinence; occasionally, fistula formation may occur in
women.
Other causes
Neurogenic
incontinence
Neurogenic incontinence
This has been dealt with in the previous
section. The common causes include:
•
myelodysplasia;
•
multiple sclerosis;
•
spinal cord injuries;
•
cerebral dysfunction [cerebrovascular accident (CVA), dementia);
•
Parkinson’s disease (paralysis agitans).
These
conditions lead to a combination of neurogenic vesical dysfunction often
associated with loss of mobility. Careful investigation of the whole urinary
tract is always required, and the treatment needs to strike a fine balance
between preventing hydronephrosis from abnormally high bladder pressures yet at
the same time maintaining continence.
The
mainstay of management is accurate urodynamic assessment to assess bladder
emptying, incontinence and the risks to the upper tract. The upper tracts should
be assessed with regular ultrasound scanning, and assessment of the patient’s
mobility, intelligence and motivation is vital. The important factors to assess
urodynamically are:
•
bladder emptying;
•
bladder capacity and bladder pressure during filling;
•
continence.
The
standard way of dealing with impaired bladder emptying is the use of CISC.
Occasionally, in an elderly immobile patient an indwelling urethral or
suprapubic catheter or an ileal conduit external urinary diversion may be
justified, or the performance of an endoscopic sphincterotomy followed by the
use of a condom appliance should be considered.
Patients
with a small functional bladder capacity (< 150 ml), a high-pressure increase
during filling (> 25 cmH2O) and a large residual volume of urine
are at high risk of developing upper tract dilatation, and in the past would
have undergone endoscopic sphincterotomy. However, there have been major changes
in the management of mobile, well-motivated patients with impaired bladder
emptying or with high-risk bladders. Such treatment will often involve major
bladder reconstruction with replacement of the high-pressure bladder with a
low-pressure substitute made of a detubularised bowel segment, often accompanied
by surgery to the bladder outflow using artificial urinary sphincters or a
colposuspension. Such treatment will usually need to be accompanied by the
patient carrying out CISC afterwards.
Small bladder
capacity
The capacity of the bladder may be
considerably diminished in several conditions. This can cause crippling urinary
frequency and incontinence. It may follow tuberculosis, radiotherapy or
interstitial cystitis. Radiotherapy for pelvic cancer can also cause this
problem.
Drug-induced
incontinence
The detrusor muscle is basically under
postganglionic parasympathetic control and the main neurotransmitter system is
cholinergic. Recent studies have established the presence of a number of
neurotransmitters
including alpha adrenergic fibres in the region of the bladder neck and other
neuropeptides, whose function is uncertain as yet, are present throughout the
bladder. A number of drugs can induce urinary retention (anticholinergic agents,
tricyclic antidepressants, lithium and some antihypertensives). Overflow
incontinence may ensue. Drugs giving extrapyramidal side-effects may induce
urinary frequency and incontinence, for example phenothiazine.
Constant
dribbling of urine coupled with normal micturition
This occurs when there is a ureteric fistula
or an ectopic ureter associated with a duplex system opening into the urethra
beyond the urethral sphincter in females, or into the vagina. The history is
diagnostic, and intravenous pyelography or ultrasound scanning may reveal the
upper pole segment which is often poorly functioning. These segments are very
liable to infection. Treatment is by excision of the aberrant ureter and portion
of kidney which needs it. A ureteric fistula can be difficult to diagnose and
may require retrograde ureterography and a high degree of suspicion to
demonstrate.
Nocturnal
enuresis
This is a condition of young children and
young adults. The time at which children become dry at night varies, of course,
and in some of them it is merely a delayed onset of continence. In others it
persists until late adolescence and is classified into primary and secondary
nocturnal enuresis.
Primary
nocturnal enuresis occurs in patients with nocturnal enuresis alone and with no
daytime symptoms. Often, they have been dry for a period and the vast majority
of patients will eventually become dry. In the meantime a sympathetic approach
to these children is essential. They often respond to a system of rewards using
a ‘star’ chart. In addition, the use of DDAVP (vasopressin analogues) can
produce increased urinary concentration at night with a decrease in nocturnal
incontinence. Other treatments include the use of amytryptiline and alarms which
wake the child (or at least the child’s parents) when incontinence occurs.
Patients
with secondary nocturnal enuresis have daytime symptoms of urinary frequency,
urgency and urge incontinence. Essentially, these patients have idiopathic
detrusor instability and should be treated in a similar way (see subsection on
‘Treatments for incontinence’).
Treatments for
incontinence
Treatments are listed below. Management is
dependent on making a correct working diagnosis. The treatment depends on the
cause. The aim is to keep the patient dry, free of odour, to lessen the
incidence of skin excoriation, and to protect the kidneys from the effects of
infection and back pressure.
Management and
treatment
Problems of social functioning. Patients with
Alzheimer’s disease, Parkinson’s disease and multi-infarct dementia are
difficult to treat. Often these patients will respond to regular toileting.
Anticholinergic agents can cause confusion in these patients and often, in
severe cases, an indwelling catheter is needed.
Storage
problems. Patients with a small capacity owing to fibrosis may require
augmentation cystoplasty. Patients with a small functional bladder capacity
owing to detrusor overactivity from neurogenic bladder dysfunction or
idiopathic detrusor instability should be tried on anticholinergic medication,
but in severe cases, particularly in neuropathic patients at high risk of upper
tract dilatation, bladder substitution (near-total supratrigonal cystectomy
followed by the need for detubularised ileocaecal segment bladder substitution)
or augmentation (enterocystoplasty) may be needed. These procedures should only
be carried out after careful assessment in units used to dealing with these
problems. Patients with very impaired mobility and MS may require ileal conduit
diversion.
Impaired bladder emptying. Patients with overflow incontinence owing to bladder outflow obstruction will respond well to prostatectomy, after an initial period of catheterisation to allow bladder and renal function to recover to some extent. Patients with impaired bladder emptying owing to neurogenic bladder dysfunction should be treated in the first place by means of CISC.
Weak
sphincter. Patients with genuine stress incontinence owing to previous prolonged
labour should be treated by means of pelvic floor exercises or colposuspension.
Those with post-prostatectomy incontinence or with neurogenic bladder dysfunction
may require fitment of an artificial urinary sphincter (Fig.
65.19) if they
are well motivated and mobile.
Leakage
from fistulae or upper tract duplication with an ectopic ureter. This will
require the appropriate surgical treatment.
Appliances
in women are usually unsatisfactory. In elderly, immobile or mentally impaired
patients, an indwelling catheter drained constantly into a leg urinal is
usually a satisfactory solution, although in some instances diversion via an
ileal conduit is necessary. In men, a condom urinary appliance may be
satisfactory, and can avoid an indwelling catheter.
More major
surgical treatments
Various types of urinary diversion. This may
be required for the treatment of end-stage incontinence that is not otherwise
treatable (see later in this chapter).
Bladder
substitution procedures. The principle behind these operations is the creation
of a low-pressure, large capacity reservoir. These can be made using any segment
of bowel isolated on its vascular pedicle (Figs 65.20,65.21,and
65.22). This is then
detubularised by dividing its antimesenteric border and suturing this into a
plate. This can then be reconfigured into a spherical structure. This
reservoir can then be anastomosed to the bladder remnant after excision of the
fundus above the trigone. If necessary, the ureters can be reimplanted into
the bowel segment. This new bladder (Fig. 65.23)
will almost certainly need to be emptied by means of intermittent self-catheterisation
(CISC).
‘Clam’
enterocystoplasty. This procedure was originally described by Bramble for the
treatment of nocturnal enuresis. It is now being used more frequently in the
treatment of idiopathic detrusor instability. It involves the isolation of a
16-cm segment of ileum on its vascular pedicle. This is divided on its antimesenteric border and
sutured into the opened out bladder. The bladder is divided along a
circumference
from bladder neck at 3 o’clock to 9 o’clock in the coronal plane (Fig. 65.24).
This procedure can also be used as an augmentation procedure in patients
with neurogenic bladder dysfunction and a reasonable preoperative bladder
capacity (approximately 300 ml).
Fitment
of artificial urinary sphincter. See Fig. 65.19.
Treatments
for incontinence
1.
Devices for collection
External penile condom, indwelling
or control
catheter, penile clamps
2. Drugs
To increase the strength of the
bladder neck (e.g. a-adrenergic
agonists), to decrease the
strength of the bladder neck (e.g.
a-adrenergic blockers), mixed
action on the bladder neck and
central nervous system (e.g.
tricyclic drugs), inhibit bladder
activity (e.g. anticholinergic drugs)
3.
Intermittent self-
catheterisation
to improve emptying
4.
Surgery to decrease outlet
Prostatectomy,
urethrotomy in
resistance
females with obstruction
5.
Increasing outlet
Pelvic floor physiotherapy,
resistance
colposuspension or slings,
periurethral collagen or silicone
particles, artificial urinary sphincter
6.
Denervation of bladder
Neurectomy procedures,
(to inhibit bladder activity
transection of bladder
and improve functional
capacity)
7. Augmentation
of bladder ‘
Clam’ enterocystoplasty, bladder
capacity
substitution with detubularised
bowel segment
8.
Urinary diversion
Ileal conduit, continent urinary
diversion