Добавил:
Sekretar
kiopkiopkiop18@yandex.ru
t.me/Prokururor I Вовсе не секретарь, но почту проверяю
Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз:
Предмет:
Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_1520_Библиотеки_им_академика_М_И_Перельмана
.pdf
348
P.J. Mitchell and E.S. Kiff
25.2 Assessment of the Patient with Fecal Incontinence
Fecal incontinence (FI) is defi ned as the involuntary loss of stool or liquid through the
anus. The true prevalence of FI is not known. There is a wide range of quoted preva-
lence of fecal incontinence because of different defi nitions, under reporting by patients,
and various forms of bias in the design of studies. After a thorough systematic review
of the literature, MacMillan et al. reported the prevalence of FI to range from 0.4% to
18% in community-dwelling adults [
1 ] . The annual UK cost of treating and managing
patients with incontinence (fecal and urinary) is £500 million [ 2 ] .
It is worthwhile remembering that fecal incontinence is a symptom/sign of an
underlying diagnosis which the clinician should be active in identifying, as this will
result in the most appropriate management . The causes of FI (Box 25.1 ) are numer-
ous, refl ecting the multiplicity and complexity of the factors involved in normal
continence.
Box 25.1: Causes of Fecal Incontinence
Traumatic Medical
Obstetric
a
Infl ammatory bowel disease
Iatrogenic
a
Diarrhea-predominant IBS
Anal stretch Celiac disease
Hemorrhoidectomy Diabetes mellitus
Sphincterotomy Lactose intolerance
Fistula surgery Psychiatric illness/behavioral
Colectomy, pouch procedures Debility/poor mobility
Radical prostatectomy Bile salt malabsorption
Colorectal Neurological
Rectal prolapse
a
Spinal cord trauma
Prolapsing hemorrhoids Spina bifi da
a
Anal/rectal neoplasm Meningocele/myelomeningocele
Multiple sclerosis
Degenerative Urogynecological
Internal anal sphincter degeneration
a
Pelvic organ prolapse
a
Congenital Cognitive
a
Imperforate anus Dementia
Anal agenesis Stroke
Hirschsprung’s disease Learning disability
Radiation damage Gastrointestinal stimulants
Anal, prostatic, pelvic radiation Drugs—any that cause diarrhea
Direct effect on internal anal
sphincter
Foods—caffeine, alcohol,
aspartame
Radiation proctitis
a
Denotes commonest causes
349
25 Assessment and Investigation of Fecal Incontinence and Constipation
Assessment of the patient with FI begins with the history. Patients will not often
volunteer all the required information, therefore the clinician may need to be direct
regarding the exact nature of the symptoms described or suggested by the patient:
The frequency and type of incontinence (either • urge suggesting poor external
anal sphincter (EAS) function or passive suggesting poor internal anal sphincter
(IAS) function) along with the stool consistency should be recorded.
The wearing of incontinence pads and the taking of antidiarrheal medication are •
also important pointers to the severity of the symptoms experienced.
The duration of symptoms should be established along with any diffi culty in •
defecation.
Childbirth is a major etiological factor in FI causing three forms of possible •
injury: traumatic injury to the sphincter complex and varying degrees of nerve
and connective tissue injury. In addition and sometimes contributing to their FI,
such patients will often have coexisting pathology such as rectoceles, descent,
and prolapse from perineal connective tissue trauma.
The clinician must also enquire about other symptoms related to other pelvic •
compartments such as uterine prolapse, urinary incontinence, and sexual dys-
function. Appropriate referrals may be required.
FI has a signifi cant physical, social, and psychological morbidity. A negative impact
upon quality of life is reported by over 50% of patients, which often leads to severe
social restriction in many instances. Patients report a wide range of behavioral changes
such as restrictions in travel, work, and exercise, a knowledge of the nearest toilets, and
carrying spare clothes, all of which are enforced upon them by their FI [
2 ] . Take time
in the clinic to listen, not only to establish the full history, but also to empathize as you
may be the fi rst person they have been able to talk freely about their problem.
A number of scoring systems exist for use in the FI patient. These can assess symp-
tom severity or impact upon quality of life (QOL). Our personal preference is the Vaizey
incontinence score [ 3 ] which takes into account not only the frequency and nature of
incontinence but also urgency, use of pads, and antidiarrheal medication. Other scoring
systems can be used, such as the fecal incontinence severity index (FISI) [ 4 ] or Wexner
continence score [ 5 ] . The fi rst validated QOL score for FI was the Fecal Incontinence
Quality of Life Scale (FIQL) developed by Rockwood et al. [ 6 ] . A similarly reliable
and valid assessment is the Manchester Health Questionnaire [ 7 ] . Such symptom and
QOL scoring systems are not only useful in the initial assessment of patients but also in
the response to different treatment strategies and long-term outcomes.
Examination of the FI patient should commence with a general abdominal exam-
ination. Careful examination of the perineum and anorectum is then required and is
detailed in Box 25.2 .
Box 25.2: Anorectal Examination in the FI Patient
Examination of the FI patient
Inspection of the
perineum
Scars from obstetric trauma or anorectal surgery,
perineal descent, skin tags, prolapsed hemor-
rhoids, fi stulae, gaping to traction (poor IAS
function), mucosal or full-thickness prolapse
350
P.J. Mitchell and E.S. Kiff
The majority of the information is obtained from the history and examination;
however, some further additional information may be provided from specialist inves-
tigations. These are discussed in more detail later and summarized in Box 25.3 .
Box 25.3: Tests of Anorectal and Colonic Function
Investigation
Clinical use
FI Constipation
Assessment of sphincter function
Anal manometry Objective measurement
of sphincter function
(resting pressures
refl ecting primarily
IAS function and
squeeze pressures
refl ecting EAS
function)
Objective measurement of
sphincter function if
considering surgery
Assessment of RAIR in
order to exclude
Hirschsprung’s disease
Vectormanometry Limited additional
benefi t to anal
manometry
No value
Assessment of sphincter structure
Endoanal ultra-
sound (EAUS)
Accurate assessment of
sphincter integrity and
appearance
Limited value, useful if
considering surgery
Endoanal MR Accurate for measure-
ment of EAS atrophy,
but otherwise, no
benefi t over EAUS
No value
Neurophysiological assessment of anal sphincters
Pudendal nerve
terminal motor
latency
(PNTML)
Limited value, too
insensitive
Limited value, too
insensitive
Digital examination Resting tone (IAS function) and tone upon voluntary
contraction (EAS function), length of anal canal,
anorectal angle, abnormal contraction when
straining, presence/absence of sphincter defects,
rectocele, intussusceptions, intra-anal prolapse
351
25 Assessment and Investigation of Fecal Incontinence and Constipation
Electromyography
(EMG)
Superseded by EAUS for
the detection of
sphincter defects
Diagnosis of paradoxical
contraction of puborec-
talis and EAS during
defecation
Anal sensation Reduced sensitivity in FI
subjects, limited value
Reduced sensitivity in
constipated subjects,
limited value
Assessment of rectal sensory function
Simple balloon
distension
Diagnosis of hyper- or
hyposensitive rectum
Diagnosis of hyposensitive
rectum
Barostat Limited value (research
setting)
Limited value (research
setting)
Assessment of rectal motor function
Defecation
proctography
Limited use, helpful in
patients with FI
secondary to recto-
cele, internal rectal
prolapse, etc.
Necessary to identify/
exclude a defecatory
disorder, and therefore
appropriate treatment
Dynamic MR Limited value Excellent for global
appreciation of all pelvic
compartments. Limited
availability at present
Balloon topogra-
phy/expulsion
test
No value Simple clinic test to help
identify subjects with a
defecatory disorder
Assessment of colonic function
Radiopaque
marker study
No value Occasionally helpful
Colonic
scintigraphy
No value Limited to research setting,
expensive, and time-
consuming
Case Scenario 2
A 29-year-old lady presents in your clinic with a history of constipation. She
has been tried with various laxatives, but her bowels are working once every 2
or 3 weeks. She has been admitted for manual evacuation on two occasions in
the past 6 months, and now both she and her doctors are desperate for help.
1. What other aspects of the history do you want to know about?
2. What investigations would you ask for?
352
P.J. Mitchell and E.S. Kiff
25.3 Assessment of the Patient with Constipation
The meaning of the word “constipation” varies widely among different people.
Some use the term to describe infrequent defecation, while others use it for diffi cult
defecation or the passage of hard stools. Commonly used in the literature is
Drossman and colleagues’ defi nition of “two or fewer stools per week and straining
at stool more than 25% of the time” [
8 ] . The Rome III criteria for the diagnosis of
functional constipation are in Box 25.4 . It is diffi cult to estimate the number of
people affected by constipation due to various defi nitions and understanding of the
term; however, it is thought to have a prevalence of between 2% and 15% [ 9 ] , while
obstructed defecation affects 7% of the adult population [ 10 ] .
Patients with chronic constipation are often referred to the surgeon from GPs and
physicians who have tried all the medical treatments without improving the symp-
toms. Such patients require a careful assessment, including suffi cient time for lis-
tening to the nature of the problem, the symptoms experienced, and the problems
encountered in day to day living, as frequently these patients feel overlooked or
discounted when seeking medical help. There are numerous endocrine, metabolic,
neurological, and pharmacological causes of constipation (Box 25.5 ) which have
often been excluded by the physician, but the surgeon should be aware of such
causes during the history and examination of the patient. It is worthwhile remember-
ing that intractable constipation that presents in the surgical clinic is a symptom of
a disease process that we do not yet fully understand :
The initial history should focus on the type of stool, frequency and completeness •
of defecation, straining, and use of digital support.
Box 25.4: Rome III Diagnostic Criteria
a
for Functional Constipation
Must include two or more of the following:
(a) Straining during at least 25% of defecations
(b) Lumpy or hard stools in at least 25% of defecations
(c) Sensation of incomplete evacuation for at least 25% of defecations
(d) Sensation of anorectal obstruction/blockage for at least 25% of
defecations
(e) Manual maneuvers to facilitate at least 25% of defecations (e.g.,
digital evacuation, support of the pelvic fl oor)
(f) Fewer than three defecations per week
Loose stools are rarely present without the use of laxatives
Insuffi cient criteria for irritable bowel syndrome
a
Criteria fulfi lled for the last 3 months with symptom onset at least 6 months
prior to diagnosis
353
25 Assessment and Investigation of Fecal Incontinence and Constipation
Symptoms of rectal bleeding and weight loss should prompt the exclusion of a •
colonic or rectal malignancy before treatment strategies are commenced.
The duration of symptoms (e.g., since childhood) or precipitating events (e.g., •
previous gynecological or gastrointestinal surgery) should be recorded.
A signifi cant number of patients will have a history of coexisting psychi atric •
problems which will often require specialist input and have been shown to
have a detrimental infl uence on the surgical management of consti pation
[ 11 ] .
As in patients with FI, the obstetric history should be noted. •
A number of symptom scoring systems for constipation exist. The Patient
Assessment of Constipation - Symptoms (PAC-SYM) questionnaire is a validated
12-item self-report measure divided into three subscales (abdominal, rectal, and
stool), which is sensitive to changes in constipation over time [
12 ] . The KESS
(Knowles Eccersley Scott Symptom) score is an alternative validated measure of
constipation comprising of 11 questions and easily completed within a few minutes
[ 13 ] . The impact of constipation can be measured using the Patient Assessment of
Constipation - Quality of Life (PAC-QOL) questionnaire. Multinational studies
Box 25.5: Causes of Constipation
Causes of constipation
Common general causes
Endocrine/metabolic
Dietary fi ber and fl uid intake, immobil-
ity, old age, environmental changes
(e.g., hospitalization/holiday)
Hypercalcemia, hypokalemia,
hyperparathyroidism, hypothy-
roidism, diabetes, pregnancy,
uremia
Neurological Psychiatric
Parkinson’s disease, autonomic
neuropathy, Chagas’ disease,
multiple sclerosis, dementia
Depression, anxiety, anorexia,
sexual abuse, psychoses
Colonic Drugs
Tumors, diverticular disease, volvulus,
slow transit constipation,
Hirschsprung’s disease, megacolon/
rectum, pseudo-obstruction,
Constipation-predominant irritable
bowel
Opiates, iron replacement,
anticholinergics, anticonvul-
sants, antidepressants, calcium
channel blockers, chronic
laxative use, NSAIDs
Obstructed defecation Collagen/muscle disorders
Rectocele, perineal descent/pelvic fl oor
weakness, prolapse, anismus, anal
stenosis
Systemic sclerosis, amyloidosis,
myotonic dystrophy,
dermatomyositis
354
P.J. Mitchell and E.S. Kiff
have demonstrated that the PAC-QOL is internally consistent, reproducible, valid,
and responsive to improvements over time [ 14 ] . It also has the advantage of assess-
ing global pelvic fl oor function. Such questionnaires may not be necessary for the
experienced coloproctologist in obtaining the history. However, they do provide a
validated measure of the symptom severity and quality of life impact. Although
limited by the problems of accurately collecting, recording, storing, and the time
available in the outpatient clinic, such scoring systems may help in identifying the
use of different treatment strategies or subgroups of patients within such a heteroge-
neous condition.
Examination of the patient with severe constipation should identify any systemic
diseases associated with constipation. Thorough examination of the perineum and
anorectum should identify causes of outlet obstruction such as rectocele, descent,
and prolapse. From the history and examination, the majority of cases can then be
appropriately classifi ed and managed accordingly.
Idiopathic chronic constipation is commonly classifi ed into three types which
will guide treatment strategies:
1. Slow transit constipation/colonic inertia—characterized by delayed transit
through the colon
2. Defecation disorder—characterized by normal colonic transit but diffi cult defe-
cation due to outlet obstruction, e.g., from a rectocele or anismus
3. A combination of both
A potential four group is the constipation-predominant irritable bowel syndrome
group, differentiated from the other three by the presence of abdominal pain as a
prominent symptom. Specialist investigations are used to complete the assessment
of such patients ensuring the correct classifi cation of constipation and therefore the
management.
25.4 Specialist Investigations
The large number of factors involved, both in maintaining continence and the act of
defecation, is refl ected in the range of investigations available. In the last 30 years,
there has been a rapid development and widespread use of a number of techniques
to investigate such patients. Some of these tests are found in most hospitals while
others are only available in specialist centers or research settings. A list of specialist
anorectal investigations and their clinical use is shown in Box 25.3 . Remember, all
these tests have certain limitations, therefore the result from a specifi c investigation
should be interpreted in the light of the individual clinical history and examination
fi ndings. There is no perfect test of anorectal function; however, they do provide
useful supplementary information. The most useful and commonly performed
investigations are discussed in further detail.
355
25 Assessment and Investigation of Fecal Incontinence and Constipation
25.5 Assessment of Anal Sphincter Function
25.5.1 Anal Manometry
Anal manometry is widely available in specialist units, easy to perform, and quanti-
fi es both the resting tone and voluntary contraction of the anal sphincters. A range
of different techniques for performing anal manometry have now been developed.
Satisfactory pressure measurements can be obtained with open-tipped or side-open-
ing water-perfused catheters, air- or water-fi lled balloons of various confi gurations,
or direct solid state microtransducers. The measurements are taken either by using
a station pull-through technique, which involves the catheter being inserted into the
anal canal and then withdrawn at intervals, or using a simultaneous channel record-
ing technique that records the pressure at sites along the catheter simultaneously.
Despite widespread use, there remains no universally accepted method for per-
forming anal manometry and no agreement on the unit of measurement, with some
centers using mmHg and others cm H
2
O. The pressure values that constitute a nor-
mal range also vary from unit to unit as there is no universally accepted fi gure, with
centers adopting their own normal range based on their experience. The defi nitions
used for parameters of resting tone and voluntary contraction also vary. Validity of
pressure measurements with the patient on their side in a room with other people is
also questioned. Ambulatory manometry may be more physiological.
The repeatability and reproducibility of anal manometry is often quoted as
satisfactory, but critical review of such reports will uncover the use of inappropri-
ate statistical methods [ 15 ] and considerable repeatability coeffi cients (maximum
difference likely to occur between repeated measurements). Ryhammer et al. per-
formed one of the largest studies of anal manometry test-retest repeatability when
they studied 58 healthy females on two separate occasions by the same investiga-
tor. They concluded that “there was no systematic variation in repeated measure-
ments for any of the parameters studied; however, the nonsystematic variation
was generally large” [ 16 ] . They found that between repeated measurements, the
mean difference for maximal anal resting pressure was 2.2 cm H
2
O, but the repeat-
ability coeffi cient was considerable at 38 cm H
2
O. For voluntary contraction, the
mean difference was −1 cm H
2
O with a repeatability coeffi cient of 35 cm H
2
O.
Pressure measurements within the anal canal vary according to age and gender.
There is good evidence from a number of large studies that both resting pressure and
squeeze pressure are greater in men compared to women and that both decrease
with aging [ 17– 19 ] . Manometry has a limited ability to discriminate between conti-
nent and incontinent individuals. On the whole, FI subjects will have lower values
of resting and squeeze pressure when compared with continent subjects [ 17, 18 ] .
However, the incontinent patient may have manometry values within the normal
range, while normal continent patients may have abnormally low pressure measure-
ments. In a study of 350 subjects, Felt-Bersma et al. [ 17 ] found that incontinent
356
P.J. Mitchell and E.S. Kiff
patients had signifi cantly lower resting and squeeze pressures compared to conti-
nent patients, but 28% of incontinent subjects had “normal” values on manometry.
McHugh and Diamant found that 39% of females and 44% of males in their group
of incontinent subjects had pressure measurements within the normal range [
18 ] .
In patients with diffi cult defecation, anal manometry may identify impaired relax-
ation or paradoxical contraction of the sphincter apparatus upon straining, or a
reduced rectoanal pressure gradient during stimulated evacuation [
20 ] . Performing
manometry in the left lateral/horizontal position, as opposed to the upright position
of normal defecation, may limit the usefulness of such results. Nevertheless, anorec-
tal manometry is essential in establishing the presence or absence of the rectoanal
inhibitory refl ex (RAIR). The pronounced relaxation of the IAS in response to dis-
tension of the rectum is absent in Hirschsprung’s disease, and manometry is particu-
larly useful in identifying even short-segment disease [ 21 ] . A full-thickness rectal
biopsy performed under general anesthesia may be required to confi rm the diagno-
sis. The main use of anorectal physiology in constipated patients is to document
baseline anal sphincter function prior to surgical intervention. The global nature of
pelvic fl oor dysfunction means that obstructed defecation frequently coexists with
anal sphincter weakness, which may be occult if the obstructive element is predomi-
nant. Clarifi cation of anal sphincter function is therefore important in predicting
likely outcomes to surgical intervention and may have medicolegal implications.
25.5.2 Vectormanometry
A radially arranged eight-channel catheter is withdrawn from the anal canal in a sta-
tion pull-through manner. The data is then analyzed by computer software to produce
a three-dimensional reconstruction of the anal canal. A vector symmetry index value
is calculated with a value of 0.6 or less shown to be associated with sphincter defects.
In a prospective study of 50 consecutive FI patients, only 5 of the 38 patients with a
sphincter defect were located with electromyography, and just 3 of the 27 patients
with a defect on ultrasonography had the same abnormality located with vectorma-
nometry [ 22 ] . Although commonly used, vectormanometry has poor correlation with
other anorectal physiological tests, and its clinical value is limited, especially in light
of the accurate assessment of sphincter integrity provided by anal ultrasonography.
25.6 Assessment of Sphincter Morphology
25.6.1 Endoanal Ultrasound
Anal ultrasonography has become an important investigation of the patient with FI.
Easily available in specialist units and quick to perform, EAUS has become the gold
standard assessment of sphincter integrity. Recent development of 3-D EAUS
357
25 Assessment and Investigation of Fecal Incontinence and Constipation
provides the clinician with excellent coronal, sagittal, and axial images of the anal
continence mechanism. A characteristic four-layer pattern is produced with the low
refl ective ring of the internal anal sphincter, the clearest landmark (Fig. 25.1 ).
All radiological investigations will be subject to variations in image interpreta-
tion by the assessor. However, the inter- and intraobserver agreement in EAUS is
very good particularly for the presence/absence of EAS defects [ 23 ] .
EAUS has aided the clarifi cation of normal sphincter anatomy, confi rming that
the anal canal is longer in males and that the anterior EAS is shorter in length in
females and only present in the mid to lower anal canal. As the thickness of the IAS
increases with age, a thin IAS (<2 mm) in patients of 50 years of age is abnormal
and secondary to primary degeneration of the IAS, whereas a thickened IAS in
younger patients is suggestive of the presence of solitary rectal ulcer syndrome.
EAUS is of great value in the patient with FI in establishing the structure and
integrity of the anal sphincters. Identifi ed defects may be amendable to surgical
repair if appropriate. The use of EAUS in constipated patients is less benefi cial but,
like manometry, is important in documenting baseline structure if surgery is being
considered.
25.6.2 Endoanal Magnetic Resonance Imaging
The development of endoanal coils in the mid-1990s led to assessment of the sphinc-
ter complex using magnetic resonance (MR) imaging. MR provides excellent tissue
differentiation, in particular the clear delineation of EAS anatomy. More time-con-
suming and expensive compared with EAUS, there is no difference between the two
modalities for the detection of sphincter defects. One area where MR is superior is
the detection and grading of EAS atrophy [ 24 ] . Such a fi nding may be a good pre-
dictor of failure after sphincter repair.
Fig. 25.1 Typical appearance
of the anal sphincters on
endoanal ultrasound.
Adjacent to the probe is a
ring of moderate refl ectivity
from the subepithelium,
which is surrounded by the
hypoechogenic ring of the
internal anal sphincter.
Around this ring is the
external anal sphincter which
is often of a more variable
echogenicity, which is in turn
surrounded by ischioanal fat
Соседние файлы в папке Библиотека им академика М.И. Перельмана