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37
S.R. Brown et al. (eds.), Contemporary Coloproctology,
DOI 10.1007/978-0-85729-889-8_3, © Springer-Verlag London Limited 2012
3.1 Introduction
Anal fi ssures are commonly diagnosed but equally often overlooked by patients and
their medical carers on the basis that symptoms overlap with other conditions, nota-
bly piles. Colorectal surgeons are aware that hemorrhoidal disease is not the cause
of all anal pain or bleeding, but this knowledge is not widespread (all that glistens is
not piles – or something like that!). We must therefore be vigilant in diagnosing anal
disease; just as we do not wish to miss malignancy, it is important to treat other
conditions appropriately, and it is thoroughly unpleasant and sadly not uncommon
for a patient enduring an undiagnosed fi ssure while having incidental hemorrhoids
treated by rubber band ligation.
The history and fi ndings in anal fi ssures do differ from other anal conditions even
if this difference is subtle. The fi ndings may not be immediately obvious, and care-
ful examination is crucial to make the diagnosis, accepting that this is likely to be
painful for the patient. Acute fi ssure can be obscured by skin folds but should be
detected by thorough examination. Careful outpatient assessment allows early and
correct treatment and will avoid additional tests including examination under anes-
thesia (EUA), rarely required in the author’s experience (some surgeons seem to
have a great fondness for assessment of anorectal conditions under anesthetic,
appropriate if there is a risk of missing signifi cant pathology, but otherwise, it should
be reserved for patients who require therapeutic intervention).
The management of anal fi ssure has evolved with our ability to modify sphincter
pressure pharmacologically, hypertonia being intimately associated with many but
A. Fowler
Department of Colorectal Surgery,
Gloucestershire Hospitals Foundation NHS Trust ,
Great Western Road , Gloucester, Gloucestershire , GL1 3NN , UK
e-mail: aidan.fowler@glos.nhs.uk
Chapter 3
Anal Fissure and Its Management
Aidan Fowler
38
A. Fowler
not all fi ssures [ 1 ] . Hypertonia may be causative or secondary, and this association
is incompletely understood. Since acute fi ssures tend to respond better to treatment
than chronic fi ssures, timely treatment should be advantageous.
3.2 Diagnosis
Anal fi ssure affects all age groups. It predominantly affects people in their third or
fourth decades, with a slight male predominance, except for women in the postpar-
tum period [ 2 ] . Anal fi ssure is a common condition, reported as the diagnosis in
approximately 10% of colorectal outpatient episodes [ 3 ] .
3.3 History (and Some Real History)
The typical history is of pain and bleeding on defecation. The pain may last for hours
and even last all day, but this is unusual. The pain is sometimes described dramati-
cally, “like passing broken glass” or “splitting of the anus,” but may just be described
as a postdefecatory ache. Description of an initiating episode of passage of hard stool
or, less commonly, an episode of diarrhea is sometimes given. Diarrhea is associated
with less than 10% of fi ssures. Bleeding is bright red and may only occur in the acute
phase. Bleeding can at times be quite profuse but generally occurs after or during
defecation and is seen on the paper. Patients sometimes localize symptoms to one
part of the anus, i.e., anterior or more commonly posterior. There may be pruritus or
mucous discharge in association with the above symptoms. The symptoms from an
anal fi ssure in ano can be severe enough to alter the course of history (Box 3.1 ).
Box 3.1: Some Real History
In 1942, the Japanese Army invaded Burma across the Thai border. Facing the
Japanese was 17th Indian Division commanded by Major General Jackie
Smyth VC. Troops had just started to cross a bridge to escape the Japanese;
there was concern that the Japanese, who were being held off, would use the
bridge to invade Rangoon.
The commander in charge had a Victoria Cross from WW1 but was suffering from a
split arse and was on strychnine injections, which meant that he should have reported
sick. However, he gave orders over the telephone wire to demolish the bridge after
only two brigades had crossed, leaving some 7000 of our troops on the wrong side.
Known as the Battle of Sittang Bridge, though some survived by makeshift rafts and
rope bridges, many more were drowned or met very sordid endings at the hand of
some unfriendly Burmese.
Kemasingki P. Major Roy Hudson: 50 years in Chaing Mai.
http://www.chiangmainews.com/ecmn/viewfa.php?id = 2899
39
3 Anal Fissure and Its Management
3.4 Examination Findings
A careful examination is required, not only because fi ssures may be obscured by
anal skin folds, but also because the pain can be very severe and preclude full exam-
ination. Digital rectal examination and instrumentation may be too uncomfortable.
Securing a diagnosis is important as other conditions may be missed where exami-
nation is incomplete.
External examination may reveal a skin tag, the so-called sentinel pile found in
chronic fi ssures and which may indeed lead patients to believe that they have a pile
since this is their understanding of such a protrusion. There may be a fi brosed anal
canal, particularly when associated with diarrhea. Fissures can occur at any position
and may be multiple, although the posterior position is most common, followed by
the anterior position (which accounts for 7% of fi ssures in males and 13% in females)
[
4 ] . There are a number of conditions that can be mistaken for an anal fi ssure
(Box 3.2 ). An unusual position is more commonly associated with other pathology
such as Crohn’s disease, which may be associated with multiple fi ssures. It is impor-
tant to look for features of skin conditions such as eczema or the dermatitis com-
monly associated with pruritus ani. In the elderly, the possibility of malignancy
should be borne in mind if any features are atypical. More recently, nicorandil has
been associated with anal ulceration [ 5 ] .
Fissures are described as acute or chronic; this may be of some prognostic value in
terms of response to medical management but otherwise has little impact on treatment
as the distinction can be somewhat arbitrary. Chronic fi ssures tend to be wider, with
internal anal sphincter fi bers visible in their base and a skin tag, and are less painful
on examination. Chronicity develops over a period of weeks. Completely painless
fi ssures should arouse suspicion and may be associated with unusual causes such as
syphilis. Fissures vary in length but are normally found below the dentate line.
Box 3.2: Causes of Anal Ulceration
common or garden •
Infl ammatory•
Anal leakage –
Neoplastic•
Squamous cancer anal canal/margin –
Infective•
Tuberculosis –
Syphilis –
Herpes –
Lymphogranuloma venereum –
Iatrogenic•
Drugs – nicorandil –
Postradiotherapy –
40
A. Fowler
3.5 Pathophysiology
Understanding the cause of the fi ssure is critical to treatment. The association of
fi ssures with increased anal canal pressure has been the basis of most treatments.
The fi ssure may result from a tear causing pain and spasm leading to an ulcer. It has
been demonstrated that oxygen tension is reduced in fi ssures, supporting the theory
that once present, fi ssures persist because of hypoxia [
6 ] . Fissures tend to occur at
the watershed of the blood supply to the anal mucosa. Blood fl ow has been shown
to improve following sphincterotomy, supporting the theory of mucosal hypoxia
[ 7 ] . Some fi ssures are precipitated by constipation, and this is normally the cause in
children; others are associated with diarrhea, but a cause is not apparent in many
patients. Pre-existing anal disease is present in a quarter to one-third of patients.
Since 80% of resting tone is generated by the internal anal sphincter (IAS), most
treatment is aimed at relaxing this muscle. Glyceryl trinitrate (GTN), diltiazem, and
other agents active on the nitric oxide pathway cause IAS relaxation, whereas botu-
linum toxin acts by irreversible binding to the motor end plates found on skeletal
muscle (i.e., external anal sphincter); its mechanism of action is therefore less well
understood when injected into the smooth muscle of the IAS.
3.6 Treatment
The principles of treatment for an anal fi ssure are shown in Box 3.3 . A different
strategy may be required for an anterior low-pressure anal fi ssure, typically seen in
women in the postpartum period and in older women (age >40). The discovery of
the nitric oxide pathway has been critical in changing the nature of treatment for
fi ssures. It must be remembered when discussing treatments that their healing rates
compared with placebo are not as impressive as fi rst they may seem, and there is
Box 3.3: Principles of Treatment of Anal Fissure
1. Soften stool
High-fi ber diet •
Laxatives •
Increased fl uid intake •
2. Soothe anal pain
Topical ointments (little evidence of effi cacy) •
Warm baths (sitz) •
3. Relax internal anal sphincter
Diltiazem/GTN •
Botulinum toxin •
Surgical sphincterotomy •
Dilatation (abandoned) •
41
3 Anal Fissure and Its Management
some evidence that medical treatment is little better than placebo and not as good as
surgery – though this must be balanced against the long-term hazards of the latter
[ 8 ] . Our experience of sequential therapy in Gloucester has been better than many
[ 9 ] , and our treatment algorithm is shown in Fig. 3.1 .
3.6.1 Conservative Treatment
It is important to consider conservative treatments which improve bowel function
fi rst, hopefully initiated by the general practitioner. This may be by advising a
change of diet, increase in fl uid intake (but be aware that caffeine has a diuretic
effect, and multiple cups of coffee may be counterproductive), or use of bulking
agents or stool softeners where necessary. There is no evidence that topical oint-
ments are effective, but they do no harm. Indeed, bran and warm sitz baths have been
shown to be more effective than topical local anesthetic and hydrocortisone [ 10 ] .
3.6.2 Medical Treatment
Medical treatments are usually appropriate as fi rst-line therapy combined with sim-
ple conservative methods, although their use remains to some extent controversial.
Diltiazem 2% or
GTN 0.2%
topically for 6–8
weeks
Conservative
treatment
Chronic anal
fissure
Acute anal
fissure
Not healed
Botulinum toxin
25 iu into sphincter
Severe pain:
patient requests
surgery
Lateral intermal
sphincterotomy
Lateral intermal
sphincterotomy
Not healed
High
pressure
Low
pressure
Anal advancement
flap
Post-partum or
other anal surgery
Ano-rectal physiology +
endo-anal ultrasound
scan
Fig. 3.1 Algorithm of for the management of anal fi ssure, outlining the treatment options at each
stage
42
A. Fowler
Nelson, in an exhaustive Cochrane review, stated that “Medical therapy for chronic
anal fi ssure, acute fi ssure and fi ssure in children may be applied with a chance of
cure that is marginally better than placebo, and, for chronic fi ssure in adults, far less
effective than surgery” [
8 ] . At this stage, it may not be clear whether sphincter tone
is raised if digital rectal examination is too uncomfortable. Anal pressure can be
reduced by a number of substances including prostaglandins, nitrates, calcium chan-
nel blockers, and cholinergic agents. In current practice, nitrates and calcium chan-
nel blockers are used. GTN is used both at 0.2% and 0.4% strength and has been
shown to reduce anal tone. GTN is applied twice daily perianally in small amounts
(“pea sized”), and patients should be dissuaded from trying to insert the tube’s noz-
zle into their anus, which does rather more harm than good. GTN acts as a nitric
oxide donor, resulting in smooth muscle relaxation, and hence also has vasodilator
activity. The higher dose does not appear to alter effi cacy but does increase side
effects, so there appears little logic for its use, though it seems to have found favor
in general practice as it is commercially available (Rectogesic
TM
). The most com-
mon side effect of GTN is headache, most commonly throbbing in nature, which
will often fade with continued use. These headaches are a signifi cant barrier to the
use of GTN for some patients. Upward of 60% of fi ssures will heal with the use of
GTN. In the author’s specialist fi ssure clinic, it has proved less effective than dilti-
azem and has been largely abandoned as fi rst-line treatment.
Diltiazem is a calcium channel blocker, which also reduces tone by smooth mus-
cle relaxation and is used in the same way as GTN. Diltiazem is used as a 2% cream
which can cause perianal irritation but is rarely associated with headaches. For this
reason, it has become the preferred option as fi rst-line treatment unless the patient has
associated pruritus or skin irritation. The period of treatment should be at least
6 weeks in the fi rst instance. The reported rate of healing for these preparations varies
from study to study and by parameter assessed, i.e., healing or resolution of pain.
If fi rst-line treatment fails, there are a number of alternative options for second-
line treatment; the choice depends on patient factors and response to fi rst-line treat-
ment. It is reasonable to continue fi rst-line treatment if there has been improvement
but incomplete healing. If the use of topical treatment has failed, then botulinum
toxin is often used as second-line treatment. Botulinum toxin works by irreversibly
blocking motor end plates on skeletal muscle which are then gradually replaced,
and normal function returns after a couple of months. Since roughly 80% of resting
pressure is a result of internal anal sphincter tone, it is perhaps surprising that a
treatment which affects the external anal sphincter should be effective; there is some
evidence botulinum toxin may have a direct effect on the IAS.
Combined sequential treatment with diltiazem and then botulinum toxin has
been shown to heal 84% of fi ssures in the author’s institution [ 9 ] . Botulinum toxin
has not traditionally been used as fi rst-line treatment because of tolerance (of the
injection) and cost. In the author’s specialist clinic with pooled patients, this cost
was brought down by multidosing from a single vial (3–4 doses from one pot); this
practice has been stopped by a recent National Patient Safety Agency alert banning
the use of single-dose vials for more than one patient. Thus, frustratingly, the poten-
tial cost saving of botulinum toxin has been lost.
43
3 Anal Fissure and Its Management
The dose of botulinum toxin and method of injection are both subjects of debate,
as are potential risks of treatment. The dose used has varied from 10 to 100 IU in 20
trials with a mean of 23 IU [ 11 ] . Techniques used vary and include bilateral injec-
tion, unilateral injection, perifi ssural injection, and remote injection. The most com-
mon technique employed is to inject either side of the fi ssure into the intersphincteric
groove, which is usually easy to palpate (an important skill to acquire before
attempting sphincterotomy). There remains lack of consensus on optimum dosage
and method of injection [
12 ] . The author uses 25 IU of toxin with half the dose
injected either side of the anus and repeated after 2 months if healing is incomplete.
If there is no response, the next step should be considered. The effect should last
several months as binding is irreversible and wears off when new motor end plates
develop. Side effects include pain or hematoma locally (we have not seen infection)
and temporary incontinence, which is reported in up to 10% of patients but has not
been seen in our experience. There is a concern that since botulinum toxin effec-
tively causes temporary denervation, muscle fi bers may atrophy while it has effect
and that therefore with repeated use, it might cause muscle weakness and inconti-
nence [ 13 ] . The evidence for this is at present theoretical, but as it has some logic,
repeated use is not advisable.
3.6.3 Surgical Treatment
Surgery is indicated when the patient is in too much pain to countenance medical
treatment or if medical treatment fails. The other indication for surgery is when
the fi ssure is known to be associated with low pressure (usually anterior and
postpartum), then nonsphincter weakening surgical treatment can be considered
and is recommended [ 14 ] . Outcomes from surgery continue to be better than
medical treatment alone [ 15 ] but has the potential for long-term complications.
Anorectal physiology, with or without endoanal ultrasound, is required in post-
partum fi ssure assessment prior to surgery and is also useful where there has been
previous surgery, a signifi cant obstetric history or an anterior fi ssure in a male.
A high resting pressure indicates that sphincterotomy should help, but this should
be performed with caution if the ultrasound shows a sphincter defect. If the pres-
sure is low (below the mean of the normal range for your unit), sphincterotomy
is contraindicated, and other techniques, such as an advancement fl ap, should be
considered. Patients with normal resting pressure require consideration of all
these options.
The most commonly used surgical treatment is lateral internal anal sphinctero-
tomy. Healing can be expected in approximately 85% of fi ssures. Noting that simi-
lar healing rates are possible with sequential medical therapy, it may be that the
healing rate is lower when sphincterotomy is used as third-line treatment in fi ssures
that are resistant to medical treatment. Sphincterotomy carries the risk of permanent
alteration in continence, usually evident as reduced fl atus control or as seepage and
soiling, usually quoted at 5%.
44
A. Fowler
Technique: Sphincterotomy is usually performed under general anesthetic with-
out muscle relaxation, although the procedure can be performed under local anes-
thetic and sedation in selected patients. The patient is placed in the lithotomy
position: after examination and assessment of the fi ssure, an anal retractor is used to
apply some gentle tension (remember the aim is not an anal stretch) to the sphinc-
ters, at which point the intersphincteric groove should be palpable. A small incision
is made laterally, avoiding the anal veins, and scissors can be used to develop the
submucosal and intersphincteric planes. At this point, the scissors can be turned,
and the muscle cut – some favor a cut up to the dentate line but a tailored sphinc-
terotomy, i.e., for the length of the fi ssure, is preferable and safer and lessens the
risk of incontinence. The procedure can also be done as a closed sphincterotomy,
using a thin iris knife (Beaver blade
TM
BD, 1 Becton Drive, Franklin Lakes, NJ,
USA 07417). Pressure may be needed to control any bleeding, and the defect in the
internal sphincter should be palpable at this point. Ultrasound postsphincterotomy
has shown a variety of errors can be made, including no evidence of internal sphinc-
ter division and division of the external sphincter. Patients with irritable bowel
symptoms with loose stool are prone to postoperative incontinence. Sphincterotomy
should be avoided as incontinence is diffi cult to treat.
Fissurectomy has been described, excising the fi brotic portion of a fi ssure, senti-
nel tag, and any enlarged anal papillae, leaving the IAS intact [ 16 ] . Combining fi s-
surectomy with botulinum toxin injection, healing is enhanced over healing with
botulinum toxin alone and is a useful alternative in those who might be at additional
risk of incontinence after sphincterotomy.
An anal advancement fl ap is a reasonable treatment for a patient with a low-pressure
fi ssure [ 17 ] , but results are poor if anal pressures are elevated. A number of fl ap tech-
niques have been described including island fl aps and Y-V advancement and rotational
fl aps. The island is an area of skin which is isolated and mobilized on the underlying
subcutaneous fat [ 18 ] ; the difference between this and a Y-V fl ap is small. The Y is the
shape as the fl ap is incised, having moved it forward; it is then sutured as a V, and either
fl ap can be moved far enough to cover a fi ssure. Rotation fl aps involve a curved inci-
sion to create rotational mobility which then allows well-vascularized skin to be rotated
into the fi ssure. In reality, these fl aps are seldom required, so few surgeons have a great
deal of experience of these techniques, although they are quite simple to perform.
Two other treatments should be mentioned from a historical perspective. The
fi rst is posterior sphincterotomy where the IAS is divided directly beneath the fi s-
sure. This technique has been abandoned because it is associated with the formation
of a “keyhole” deformity which can lead to mucous leakage. The second is anal
dilatation/stretch, a technique which was popular until relatively recently. Despite
often being described as “controlled” (some surgeons claimed they could feel the
IAS fi bers gave and stopped at that point), it has at times been anything but con-
trolled and can cause severe IAS disruption. Endoanal ultrasound scans from
patients with incontinence following anal dilatation reveal the degree of disruption
that can occur. For this reason, dilatation is now rarely used despite reported series
of good results [
19 ] . Anal stretch has a higher risk of fi ssure persistence than inter-
nal sphincterotomy and also a signifi cantly higher risk of incontinence [ 20 ] .
45
3 Anal Fissure and Its Management
3.7 Pediatric Fissures
Most pediatric fi ssures are relatively acute and respond to conservative treatment
and are likely to heal in a couple of weeks. For a chronic fi ssure, GTN has been
shown to be effective whereas there is little information on the use of diltiazem and
botulinum toxin in pediatric fi ssures.
3.8 Diffi cult or Reluctant Fissures
Patients with an unhealed fi ssure should be assessed to make sure that the diagnosis
is still correct and that sphincter pressure has been reduced by adequate sphinctero-
tomy: anorectal physiology and endoanal ultrasound are very useful in this situation.
If pressures remain high and there has been minimal division of the internal sphinc-
ter, then repeat open sphincterotomy is justifi ed. In some patients, the reason for the
persistent fi ssure is not found. There is no magic solution for these patients, but there
are important points to note. The fi ssure will eventually heal, and this seems to occur
over a period of a couple of years. The question is how much the patient suffers in
the mean time. After a series of treatments, the symptoms often reduce, even if they
do not go altogether. It is better to support someone through their treatments rather
than to render them incontinent with injudicious surgical treatment.
3.9 Conclusions
Anal fi ssure is common. The diagnosis should be considered in all patients with pain and
bleeding, and the surgeon should be aware of other possible causes of anal ulceration.
The diagnosis is usually easily made after clinical examination. A variety of effective
medical treatment options are available, and the surgeon should follow a logical treat-
ment algorithm to obtain healing of the fi ssure at the lowest risk to long-term continence.
Sphincterotomy remains the preferred surgical treatment with a high success rate and
remains the “gold standard” against which other newer treatments should be compared.
Key Points
Fissure in ano is common ~10% of colorectal OPD referrals. •
It is relatively easily diagnosed with typical history and examination fi ndings. •
Be aware of potential alternative diagnoses. •
Consider medical treatment fi rst in most cases. •
Botox is an effective second line treatment. •
Sphincterotomy is the surgical treatment of choice after appropriate investiga-•
tions with better outcomes than any other treatment but potential side effects.
46
A. Fowler
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