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improved outcomes in colon and rectal surgery
155. Consten CJ, Siors FJM, Noten HJ et al. Anorectal surgery
in human immunodeficiency virus-infected patients. Dis
Colon Rectum 1995; 38: 1169–75.
156. Miles AJG, Mellor CH, Gazzard B et al. Surgical management
of anorectal disease in HIV-positive homosexuals. Br J Surg
1990; 77: 869–71.
157. Munoz-Villasmil J, Sands L, Hellinger M. Management of
perianal sepsis in immunosuppressed patients. Am Surg
2001; 67: 484–6.
158. Onerheim RM. A case of perianal mucinous adenocarcinoma arising in a fistula-in-ano: a clue to the early pathologic diagnosis. Am J Clin Pathol 1988; 89: 809–12.
159. Seya T, Tanaka N, Shinji S et al. Squamous cell carcinoma
arising from recurrent anal fistula. J Nippon Med Sch 2007;
74: 319–24.
160. Korelitz BI. Carcinoma of the intestinal tract in Crohn’s disease: results of a survey conducted by the National Foundation
161. Smith R, Hicks D, Tomljanovich PI et al. Adenocarcinoma
arising from chronic perianal Crohn’s disease: case report
and review of the literature. Am Surg 2008; 74: 59–61.
162. Sarani B, Orkin BA. Squamous cell carcinoma arising in an
unhealed wound in Crohn’s disease. South Med J 1997; 90:
940–2.
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20
POSTERIOR
ANTERIOR
Acute and
Chronic anal fissure
Acute
and
Chronic
anal fissure
Crohn’s disease
Ulcerative colitis
Syphilis
Tuberculosis
Leukemia
Cancer
HIV
Crohn’s disease
Ulcerative colitis
Syphilis
Tuberculosis
Leukemia
Cancer
HIV
Surgery and nonoperative therapy of anal fissure
Jaime L Bohl and Alan J Herline
CHALLENGING CASE
A 35-year-old woman presents with a recurrent posterior anal
fissure. She had a left lateral anal sphincterotomy 4 years ago for
an unresponsive anal fissure. Her fissure healed until 6 months
ago. She has had two previously vaginal deliveries. Exam reveals
a posterior anal fissure with exposed sphincter muscle and a sentinel skin tag. Anal manometry revealed mildly decreased resting pressure and a hypertonic squeeze pressure. The patient’s
symptoms have not responded to stool softners and topical
medication.
CASE MANAGEMENT
A repeat sphincterotomy is relatively contraindicated due to the
decreased sphincter function. An acceptable surgical option is an
advancement flap.
INTRODUCTION
An anal fissure is a longitudinal tear or ulcer in the anal canal
from the dentate line to the anal verge. Fissures affect both genders
equally, across age groups with young and middle aged adults constituting the majority of patients.(1) Although the true incidence
is not known, anal fissure is common. In a survey of Italian proctology clinics, 10% of 15,000 consecutive referrals were diagnosed
with anal fissure.(2)
Fissures can be classified by etiology, location, and chronicity. It
is hypothesized that most fissures are caused by trauma to the anal
canal, usually from passage of hard stool. Anal fissures are commonly located in the posterior midline (75%), although a smaller
percentage can be found in the anterior midline (13%) and an
anterior and posterior location may be seen simultaneously (11%).
Anterior fissures are seen more commonly in women (19%).(1)
Fissures may be associated with other chronic medical conditions
such as Crohn’s disease, HIV/AIDS, tuberculosis, syphilis, or anal
carcinoma. Fissures in patient with these conditions typically
occur off the midline and may be multiple or irregular (Figure
20.1). These fissures are best treated according to the underlying
disease state. Early or acute fissures are a simple linear tear in the
anoderm. Fissures that have been present for >4 weeks show signs
of chronicity: the base of the fissure reveals internal sphincter fibers
with indurated edges, and a sentinel pile (cranial) or hypertrophied
apical papilla (distal). The chronicity of a fissure is important to
discern from patient history and clinical exam as this will affect
treatment recommendations.
PATHPHYSIOLOGY
The exact mechanisms leading to acute anal fissure and the
factors that encourage fissure chronicity have been the subject
of debate. However, anatomic and physiologic studies suggest
an ischemic etiology to anal fissure chronicity. In 1986 Gibbons
and Read confirmed that patients with anal fissures had elevated
Figure 20.1 Fissure location related to etiology.
anal resting pressures and they hypothesized that elevated anal
resting pressures led to tissue ischemia and ulceration within
the anal canal.(3) This hypothesis was further supported by
anatomic studies performed by Klosterhalfen and colleagues
who showed that the posterior anal canal has a limited blood
supply compared to the rest of the anal canal.(4) The decreased
blood supply to the posterior anal canal was evident through the
lack of inferior rectal artery branches to the posterior anal commissure in 85% of postmortem specimens, and the decreased
capillary density in histologic specimens.(4) Schouten and
colleagues put these findings together when they demonstrated
an inverse relationship between anal resting pressure and anodermal blood flow.(5) Therefore, patients with anal fissure have
less blood flow to their posterior midline secondary to anal
hypertonia. The ischemia in the posterior midline allows persistence of anal fissures and poor healing. Treatments for anal
fissure are therefore aimed at decreasing anal hypertonia and
increasing anodermal blood flow.
Anal fissures can be exquisitely painful despite the small size
of the lesion. Patients complain of sharp, persistent pain during and after defecation, which may lead patients to avoid bowel
movements. Patients may also notice blood on the toilet tissue or
coating the stool with limited bleeding or perianal swelling.
improved outcomes in colon and rectal surgery
DIAGNOSIS
The clinician should inquire about known risk factors for fissure
including alteration in bowel habits (constipation or diarrhea),
childbirth, previous anorectal surgery, or associated medical conditions. The clinician should also inquire to previous episodes
of the presenting symptom complex. The natural history of anal
fissure is one that waxes and wanes, sometimes with healing
between recurrences.
Anal fissure can be diagnosed by inspection of the anus. Patients
are usually too symptomatic to allow for digital examination or
anoscopy at the initial visit. If the clinician suspects another diagnosis because of an atypical location, the presence of multiple or
chronic fissures, or a fissure cannot be diagnosed by inspection, then
exam under anesthesia may be necessary. Suspicion of an alternative
diagnosis may warrant biopsy and culture of the anal lesions.
TREATMENT
Anal fissures have been treated with a variety of medical and surgical therapies. A growing body of randomized controlled trials has
helped to guide current treatment recommendations for anal fissure. Currently available treatments include conservative therapy,
nitrates, calcium channel blockers, botulinum toxin, anal dilation,
open or closed lateral sphincterotomy, and anal advancement flap.
Conservative therapy comprises increased dietary fluid and fiber,
sitz baths, and stool softeners. Nitrates may include ointments of
nitroglycerin (NTG) or glyceryl trinitrate (GTN), nitroglycerin
transdermal patch, or other nitrate analogs such as isosorbide
dinitrate (IDN) or isosorbide mononitrate (IMN). Calcium channel blockers have been used in ointment or tablet form (diltiazem
or nifedipine). Finally, botulinum toxin (BT) has been used in
the treatment of anal fissure. It is sold in two commercially available preparations, Dysport (Speywood Biopharm Ltd, Wrexham,
UK) and Botox (Allergan, Irvine, CA, USA). Both preparations of
BT have been shown to have equal efficacy in the treatment of
chronic anal fissure (6) with 100 units of Dysport toxin having the
bioequivalence of 20 units of Botox. All of these medical and surgical treatments have been used in randomized controlled trials to
assess the effect on fissure healing rates, anal resting pressure, pain,
and fissure recurrence. Other treatment effects which are important to consider are complications such as incontinence to flatus or
stool, headache, hypotension, and allergic reactions. Importantly,
two recent meta-analyses of all medical and surgical treatments
used for anal fissure are available.(7–10) This has lead to improved
decision making regarding the treatment of anal fissure.
Conservative therapy is often used as a comparison to other
medical or surgical treatment. The effect of conservative therapy on
healing rate for anal fissure has been 50% for acute (11) and 34%
for chronic anal fissures.(7) Therefore, other medical and surgical
treatments should be tested with this therapy in mind. The effect
of conservative therapy on anal fissure healing rate, reduction in
symptoms, and safety profile has lead to the recommendation by
the American Society of Colon and Rectal Surgeons for conservative therapy to be the first line treatment of anal fissure.(12)
ACUTE ANAL FISSURE
Clinical experience dictates that over half of acute anal fissures will
heal within several weeks. Therefore, most clinicians recommend
conservative therapy for acute anal fissure. Conservative therapy
consists of fiber supplements and sitz baths with or without the use
of topical anesthetics. However, few randomized controlled trials
have evaluated acute anal fissure healing with conservative therapy
as compared to no therapy. One trial compared warm sitz baths
and 10 g of unprocessed bran to 2% lignocaine ointment or 2%
hydrocortisone ointment applied in the anal canal twice per day.
(13) After 3 weeks of treatment, patients treated with bran and sitz
baths had significantly more healed fissures (88%) than patients
treated with lignocaine ointment (60%). Unfortunately, patients
with healed fissures were not followed long-term and rates of fissure recurrence were not measured. One randomized controlled
trial does suggest the ability of long-term conservative therapy to
prevent fissure recurrence.(14) Ninety patients with recently healed
posterior anal fissures were randomized and blinded to three different treatments groups for 1 year. Patients received either 5 g
unprocessed bran three times a day, 2.5 g unprocessed bran plus
2.5 g placebo, or 5 g placebo. Patients receiving 5 g of unprocessed
bran over 1 year had significantly fewer recurrences of anal fissure
(16%) as compared to patients who received the lower bran dose
(60%) or placebo (60%). In addition, within 6 months of discontinuing treatment, the recurrence rate between the three groups
was similar. Finally, one study evaluated the role of sitz baths in
symptom relief and acute anal fissure healing while also providing
psyllium supplementation over 4 weeks.(15) Although there was
a trend toward improved pain scores after defecation and overall
intensity of pain, there were no significant differences in fissure
healing between groups (85%). The authors hypothesize that sitz
baths provide transient pain relief via a thermosphincteric reflex
which allows for decrease in sphincter tone and temporary pain
relief. However, sitz baths do not lead to long-term reduction in
anal tone that allows for fissure healing. Overall, these studies
show that fiber therapy is more effective in preventing acute anal
fissure recurrence, but only suggest that fiber therapy can improve
acute fissure healing.
In an effort to improve acute anal fissure healing rates and
maintain healing, some investigators have added anal dilation or
pharmacologic agents to conservative treatment. One study shows
no additional therapeutic benefit of twice daily anal dilation in
combination with stool softener and lignocaine jelly.(16) Another
small randomized study that included patients with both acute
and chronic fissures compared topical nitroglycerin to topical
xylocaine.(17) In patients who had acute fissures, those receiving
topical nitroglycerin had fissure healing rates of 92% compared
to 0% of the control arm after 14 days of therapy. This treatment
effect persisted, with the same number of patients in the nitroglycerin group maintaining healing at 28 days compared to 50%
of patients who received xylocaine ointment. No long-term follow-up data was provided and all treatment failures were referred
for lateral sphincterotomy. A larger randomized trial examined
the healing rate of acute anal fissure after treatment with 0.2%
nifedipine ointment twice daily compared to conservative therapy.
(18) Patients who received nifedipine treatment had higher fissure
healing rates compared to conservative therapy (98 vs. 60%) after
4 weeks of treatment. One novel approach to achieve acute anal
fissure healing has been to compare the efficacy of gonyautoxin,
a paralyzing phytotoxin, to normal saline placebo which are both
200
surgery and nonoperative therapy of anal fissure
Table 20.1 Randomized Controlled Trials of Nitrate Therapy versus Placebo for the Treatment of Chronic Anal Fissure.
Author/Year
Number
Patients
Treatment Groups
(%)
Length
Treatment
(weeks)
Fissure Healing
Rates (%)
Side Effects (%)
Follow-up
(months)
Recurrence
(%)
Lund 1997 (24) 80 P vs. 0.2 GTN
BID
Kennedy 1999 (27)
Altomere 2000 (26) 132 P vs. 0.2 GTN
Chaudhuri 2001 (25)
Maan 2004 (28) 64 P / 5 xylocaine /
Carapeti 1999 (29) 70 P / 0.2 / 0.2+0.1qwk
Bailey 2002 (30) 304 P / 0.1 / 0.2 / 0.4 NTG
Scholfield 2003 (31) 200 P / 0.1 / 0.2 / 0.4 GTN
Wierre 2001 (31) 37 P vs. 1 IDN
Tankova 2002 (32) 19 P vs. 0.2 IMN
Note: P = placebo; GTN = glyceryl trinitrate; BID = twice per day; HA = headache; TID = three times per day; NR = not recorded; NS = not statistically significant;
NTG = nitroglycerin; IDN = isosorbide dinitrate; IMN = isosorbide 5-mononitrate.
43 P vs. 0.2 GTN
TID
BID
19 P vs. 0.2 GTN
BID
proctosedyl / 0.2 GTN
BID
GTN
TID
BID or TID
BID
5x/day
BID
8 8 vs. 68
(p < 0.0001)
4 16 vs. 46
(p = 0.001)
4 52 vs. 49
(p = ns)
6 22 vs. 70
(p < 0.05)
6 25 vs. 94
(p < 0.0001)
8 32 vs. 67 all GTN
(p = 0.008)
8 50- all groups
(p < 0.62)
8 38 vs. 47 all GTN
(p = 0.3)
10 35 vs. 85
(p < 0.003)
3 22 vs. 80 HA: 0 vs. 20 3 None
HA: 18 vs. 58
(p < 0.05)
HA: 21 vs. 29
Discontinued treatment: 13
HA: 8 vs. 34 (p = 0.001)
Orthostatic hypotension: 6
Not reported 3 None
HA: 0 vs. 19 None NR
HA: 27 vs. 72 all GTN
(p < 0.001)
Discontinued treatment: 3.3 None NR
HA: 13 vs. 31 all GTN
(p < 0.01)
HA:18 vs. 45 10 33 vs. 12
4 11.5%
GTN
29 NR
3 19% GTN
9 43 vs. 29
(p = 0.7)
None NR
injected into the internal anal sphincter.(19) This study included
17 patients with acute anal fissure and was eventually unblinded
secondary to a large treatment effect of the toxin. Patients with
acute anal fissures had a healing rate of 100% at 15 days as compared to 0% of the 3 patients who received placebo. All patients
who were injected with the toxin showed a significant decrease
in anal resting pressure from baseline. Complications included
minor bleeding but did not result in any cases of incontinence to
stool or flatus. After 14 months of follow-up this treatment effect
has been maintained. In all, these studies show that the addition of
a pharmacologic agent can increase the healing rates of acute anal
fissure; however, larger trials are needed to replicate these results.
CHRONIC ANAL FISSURE
Medical Therapy
Anal fissure chronicity is attributed to sphincter hypertonia and
decreased anodermal blood flow in the posterior anal canal. Pharmacologic manipulation of the hypertonic internal anal sphincter has
been sought, given the permanent changes that can occur with surgical intervention. Medical treatments that result in temporary relaxation of the internal anal sphincter or chemical sphincterotomy have
been used in the treatment of chronic anal fissure.
Nitrates
Nitrates have been shown to have a relaxing effect on the human
internal anal sphincter (IAS). Ex vivo studies on the human
IAS show that nitric oxide (NO) mediates sphincter relaxation
through enteric inhibitory neurons which are found within the
muscle fibers.(20) Nitrates which are NO donors are readily available pharmacologic agents. Loder et al. demonstrated that GTN
ointment causes a decrease in anal resting pressure in normal and
anal fissure patients which was comparable to sphincterotomy.
(21) Schouten and colleagues then showed that anal resting pressure decreased and anodermal blood flow increased after chronic
anal fissure patients were treated with isosorbide dinitrate.(22)
They concluded that the reduction in anal sphincter pressure and
increased blood would contribute to early pain relief, while fissure healing would require more time. More recent studies have
shown conflicting data on the ability of nitrates to significantly
decrease anal resting pressure in chronic anal fissure patients.
Thornton et al. clarified these conflicting results with a regression
analysis which showed that patients who were mostly likely to
heal their fissure in response to nitrate therapy were those with
higher pretreatment anal resting pressures and a greater percent
reduction in posttreatment anal resting pressures.(23) Based on
these physiologic studies, nitrates have become an obvious choice
for the pharmacologic treatment of chronic anal fissure.
Nitrates versus Placebo
There are ten randomized controlled trials in the English literature which compare nitrate therapy to placebo or conservative
therapy in adults with chronic anal fissure. (Table 20.1) There
have been a variety nitrate preparations, ointment strengths,
20
improved outcomes in colon and rectal surgery
schedules, treatment length, and instructions for nitrate administration that have been utilized in these studies.
Five randomized controlled trials have measured the effect of
0.2% GTN ointment in comparison to placebo.(24–28) In these
studies a total of 338 patients were instructed to apply an active
versus inert ointment to their anal canal either twice or three time
daily for a period of 4 to 8 weeks. Outcome measures included
fissure healing, pain, mean anal resting pressure (MARP), fissure
recurrence, and ointment side effects. Four of these studies were
able to measure an increase in anal fissure healing rates with nitroglycerin ointment compared to placebo.(24, 25, 27, 28) However,
there was a wide range of GTN treatment effect (8–52% placebo vs. 46–94% GTN). The fifth and largest study included 132
patients and did not measure a difference in healing rates between
the placebo and GTN ointment (52% vs. 49%).(26) In four studies, pain was reported as a secondary outcome. In three studies
pain was significantly decreased after treatment compared to pain
at time of trial entry in both GTN and placebo groups.(24, 26, 27)
However, only one study measured a significant difference in pain
scores between GTN and placebo treatment groups.(28) All five
studies measured treatment effect on MARP. Two studies measured a decrease in MARP after treatment compared to time at trial
entry for both placebo and GTN groups.(25, 26) In the other three
studies, only the GTN treatment group had a significant decrease
in MARP.(24, 27, 28) One trial reported loss of decreased MARP
48 hours after discontinuing GTN therapy.(27) The most significant side effect of nitrate therapy was headache. In four trials,
there was a higher rate of headaches in GTN patients (19–58%)
compared to placebo treated patients (0–21%).(24, 25, 27, 28)
There was also a difference in the severity of headache reported
between these two groups.(27) Ultimately, headaches lead to subsequent decreases in dose or discontinuation of GTN for several
patients in each trial. In two studies there was an attempt to follow
patients long-term.(24, 26) The rate of fissure recurrence in the
GTN treated group was 11.5–19% after 3–4 months of follow-up.
Overall, these five trials suggest a slightly increased rate of anal fissure healing with GTN ointment compared to placebo. However,
there is an increased incidence and severity of headache with
GTN treatment which may require a decreased dose for continued
patient compliance. Despite healing, there may be a high rate of
fissure recurrence within several months of follow-up.
Three additional trials have tested the effect of increasing doses
of GTN ointment on anal fissure healing rate, MARP, pain scores,
headache, and anal fissure recurrence.(29–31) Two trials compared placebo with 0.1%, 0.2% and 0.4% GTN ointment (B,S).
The third trial compared placebo with 0.2% GTN ointment and
an increasing dose of GTN ointment which started at 0.2% and
was increased by 0.1% every week to a dose of 0.6% GTN.(28) All
treatment was administered for 8 weeks and applied either BID or
TID. In these trials there was only one that measured a difference
in fissure healing rate of the GTN treatment group compared to
placebo.(29) There were no differences found in fissure healing
rate with changes in GTN dose. One trial reported a 21% reduction in pain when treated with 0.4% GTN compared to placebo.
(30) There was no difference in pain scores between placebo and
GTN or between GTN doses in the other studies.(29, 31) Across
these three trials, MARP was not uniformly decreased in the nitrate
treated group compared to baseline. All three studies reported a
high incidence of headache in the GTN group (31–72%) compared to placebo (13–27%). Headaches were more frequent and
severe with increasing dose of GTN ointment. Follow-up was
performed in one study. One third of anal fissures that initially
healed recurred within 9 months.(29) These trials demonstrate
that increasing doses of GTN do not increase the rate of fissure
healing or improve fissure related pain, but do result in more
severe and frequent headaches. Again, recurrence when reported,
occurs in up to one-third of patients.
Two additional studies have used alternative nitrate preparations for the treatment of chronic anal fissure for comparison
with placebo. Wierre et al. used 1% isosorbide dinitrate ointment five times per day for 10 weeks.(32) There was a significant
difference in fissure healing rate between placebo and active ointments (35 vs. 85%). However there was no significant change in
MARP throughout the trial period. There was also a significant
incidence of headache in the treatment group (45%) compared to
placebo (18%) with 10% of patients in the active treatment discontinuing therapy. Thirty-three percent of patients in the active
treatment arm had fissure recurrence and requested alternative
therapy. Tankova et al. used 0.2% isosorbide mononitrate on
chronic anal fissures compared to placebo administered BID over
a 3 week treatment course.(33) Eighty percent in the active treatment arm healed their fissures compared to 20% in the placebo
group. Twenty percent in the active group had headaches which
were treated with mild analgesics. No recurrences were seen in
3 months of follow-up. The authors of both these studies agree
that different nitrate preparations can be used to treat chronic
anal fissure but that more studies are required to determine the
optimal preparation, dose, and schedule of nitrate therapy.
Two studies have compared 0.2% GTN ointment to a transdermal nitroglycerin patch for either 6 or 8 weeks of treatment.(34, 35)
In both studies the transdermal patch was a 10 mg dose that was
applied for either 12 or 24 hours. These studies found that both
preparations resulted in equivalent fissure healing rates at 6 weeks
(65–73%), 8 weeks (63–67%) and 12 weeks (79–81%). One trial
reported a decrease in pain from baseline by 50% in both the ointment and patch patients.(35) The rate of headache was substantially
lower in one study (16–19%) (34) compared to another (63–72%)
(35) but both studies reported the headache to be responsive to
mild analgesics and equal in occurrence between the two treatment groups. Six percent of patients in one study reported transient
incontinence to flatus which had resolved by the time of trial resolution.(35) Recurrence at 3 months for one trial occurred in 9–15%
(34) patients and 25% in the other.(35) In all, 0.2% GTN ointment
seems equivalent to transdermal patch in the rate of anal fissure
healing, pain relief, side effects, and recurrence.
Overall, chronic anal fissure healing rates after treatment with
nitrates (49%) may be slightly improved compared to placebo
(37%).(7) Nitrate therapy may decrease pain associated with anal
fissure but with a concomitant increase in headaches (27%) that
can lead to noncompliance. Given the side effect profile and high
recurrence rates after nitrate therapy (33%), the patient may request
alternative therapeutic interventions. Nitrate therapy remains a
treatment alternative for patients wanting to avoid surgery and
does not exclude the patient from other therapies in the future.
202
surgery and nonoperative therapy of anal fissure
Table 20.2 Randomized Controlled Trials of Nitrates versus Surgical Sphincterotomy for the Treatment of Chronic Anal Fissure.
Author/
Year
Number
Patients
Treatment Groups
(% ointment)
Length of
Treatment
(weeks)
Fissure
Healing (%)
Overall
Side-effects (%)
HA %
IC Flatus
(%)
Follow-up
(months)
Recurrence
(%)
Oettle
1997 (40)
Richard
2000 (36)
Evans
2001 (37)
Libertiny
2002 (38)
Parellada
2004 (39)
Mishra
2005 (41)
Note: NTG = nitroglycerin; LIS = lateral internal sphincterotomy; TID = three times per day; NS = not statistically significant; NR = not recorded; GTN = glyceryl
trinitrate; IDN = isosorbide dinitrate.
Nitrates versus Sphincterotomy
Nitrate therapy has been compared to internal sphincterotomy for
the treatment of chronic anal fissure. Six studies have compared
these two treatments in a randomized controlled fashion.(36–41)
(Table 20.2) Four studies found internal sphincterotomy to be
superior to nitrate therapy for fissure healing after 6–8 weeks.
(36–39) The two studies which showed no difference in fissure
healing between treatment groups, were smaller and measured a
larger nitrate treatment effect than is traditionally seen (83–90%).
Richard and colleagues found nitrate therapy to help fissure related
pain despite poor fissure healing (36). Parellada and colleagues
found a posttreatment decrease in MARP from baseline in both
treatment groups (30%) without a significant difference between
groups.(39) Four studies found a significant rate of headaches
in nitrate treated patients.(36–38, 41) These headaches caused
significant problems with patient compliance and 20–30% of
patients discontinued ointment application. In comparison, there
were relatively few and minor side effects in patients undergoing
sphincterotomy. While one study measured a high rate of postoperative incontinence to flatus (44%), this decreased to 15% after
2 years follow-up.(39) Initially, Richards et al. did not find any
24 NTG/ LIS
TID
82 0.25/0.5 GTN/LIS
TID
60 0.2 GTN/LIS
TID
70 0.2 GTN/LIS
TID
54 0.2 IDN/LIS
TID
40 0.2 GTN/LIS
BID
4 83 vs. 100
(p = NS)
6 30 vs. 90
(p = 0.00)
8 61 vs. 97
(p < 0.001)
8 54 vs. 100
(p = 0.02)
6 67 vs. 96
(p < 0.001)
6 90 vs. 85
(p = 0.347)
NR NR NR 1 NR
84 vs. 29
(p < 0.0001)
NR 33 7.4 5 45 vs. 4
NR 20 2.8 24 16 vs. 2.8
30 vs. 44
(p = NR)
40 vs. 70
(p = NR)
21 None 6 38 vs. 3
NR 44 @ 5 wk
15 @ 24 wk
15 15 4 NR
24 13 vs. 0
chronic anal fissure. Calcium channel antagonists have been used
as alternative agents for temporary chemical sphincterotomy.
Calcium is necessary for tonic contraction and spontaneous activity in the IAS smooth muscle.(42) When IAS muscle is subjected
to a calcium channel antagonist, nifedipine, tone and spontaneous
contraction of the muscle is inhibited. Therefore, a calcium channel antagonist may reduce the IAS hypertonia that is observed
in chronic anal fissure. Indeed, nifedipine has been shown to
decrease anal resting pressure in normal controls and patients
with anal fissure or hemorrhoids.(43) Nifedipine decreased anal
resting pressure by approximately 30% in all groups. Decreased
anal pressure is thought to cause increased anodermal blood flow
and allow for fissure healing. Carapeti and colleagues showed that
diltiazem ointment significantly reduced anal resting pressure
and allowed for 67% of patients with chronic anal fissure to heal
over 8 weeks. However, they were unable to measure a significant
difference in anodermal blood flow using laser Doppler before
and after diltiazem administration.(44) Due to the ability of calcium channel antagonists to reduce anal resting pressure, they
have been used as alternatives to nitrates for chemical sphincter-
otomy in patients with chronic anal fissure.
difference in immediate postoperative continence scores between
patients treated with nitrates or sphincterotomy.(36) After 5 years,
the investigators contacted 62% of the study patients. With the
use of a sensitive incontinence scale, there were still no differences in continence scores between the two groups. However, 2/3
of patients reported some degree of incontinence. Finally, fissure
recurrence occurred rarely in patients undergoing sphincterotomy (0–4%) compared to high rates of recurrence among patients
treated with nitrates (13–45%). In all, nitrates are significantly less
effective than sphincterotomy for fissure healing, acute relief of
pain, fissure recurrence, and number of treatment side-effects
when administered for treatment of chronic anal fissure.
Calcium Channel Antagonists versus Placebo
One study has compared the efficacy of a calcium channel antago-
nist, nifedipine to a treatment consisting of lidocaine, and hydro-
cortisone ointment for the treatment of chronic anal fissure.(45)
(Table 20.3). One hundred and ten patients were given either 0.3%
nifedipine ointment or 1.5% lidocaine plus 1.0% hydrocortisone
ointment for twice daily application over 6 weeks. Patients who
were given nifedipine ointment had a significant reduction in anal
resting pressure (11%) from baseline after 3 weeks of treatment. In
addition, 95% of these patients had a healed fissure after 6 weeks.
Positive treatment effects were not seen in the placebo treatment
arm with manometric studies measuring a 4.4% increase in anal
Calcium Channel Antagonists
Given the frequency of adverse side effects with nitrate therapy,
other medical treatments have been sought for patients with
resting pressure, and only 16% of patients experienced fissure
healing. The patients did not report any side effects. Six percent of
patients treated with nifedipine had fissure recurrence, 66% were
20
improved outcomes in colon and rectal surgery
Table 20.3 Randomized Controlled Trials of Calcium Channel Blockers for the Treatment of Chronic Anal Fissure.
Author/
Year
Number
of Patients
Treatment Groups
(% ointment)
Length of
Treatment
(weeks)
Fissure
Healing
(%)
Overall
Side
Effects (%)
Follow-up
(months)
Recurrence
(%)
Perrotti
2002 (45)
Kocher
2002 (47)
Bielecki
2003 (46)
Ezri
2003 (49)
Mustafa
2005 (50)
Shrivastava
2007 (48)
Ho
2005 (51)
Katsinelos
2006 (52)
Jonas 2001
(53)
Note: N = nifedipine; BID = two times per day; NR = not recorded; GTN = glyceryl trinitrate; D = diltiazem; QID = four times per day; NS = not statistically significant;
LIS = lateral internal sphincterotomy; TS = tailored sphincterotomy; TID = three times per day.
retreated and, once again, their fissure healed. This is in comparison to 55% recurrence in the placebo arm. Of the 47 patients who
did not achieve fissure healing or who suffered a recurrence after
placebo treatment, 45 elected to have nifedipine treatment at the
110
60 0.2 GTN vs. 2 D BID 6–8 86 vs. 77
43 0.5 GTN vs. 2 D BID 8 86 vs. 86
52 0.2 GTN vs. 0.2 N QID 24 58 vs. 89
20 0.2 GTN vs. 20 mg PO N BID 8 70 vs. 60
90 P vs. 0.2 GTN vs. 2 D BID 6 33 / 73 / 80
132 LIS vs. TS vs. 20 mg PO N BID 6 96/ 95/ 16
64 LIS vs. 0.5 N TID 8 100 vs. 97
50 60 mg PO D vs. 2 D BID 8 38 vs. 65
1.5 lidocaine + 1.0
hydrocortisone vs. 0.3 N BID
6 16 vs. 95
(p < 0.001)
(p = 0.21)
(p = 0.95)
(p < 0.04)
(p = NS)
(p = <0.02)
(p < 0.001)
(p = 0.49)
(p = 0.09)
recurrence, and side effects. These two studies demonstrate that
multiple preparations of calcium channel antagonists may be used
for the treatment of chronic anal fissure with equal healing efficacy
and fewer side effects than GTN ointment.
None 18 55 vs. 6
72 vs. 42
(p = 0.01)
33 vs. 0
(p = NR)
40 vs. 5
(p < 0.01)
30 vs. 10
(p = NR)
0 / 67 / 0
(p = NR)
No
difference in
continence
19 vs. 50
(p = NR)
33 vs. 0
(p = 0.001)
3 2 vs. 0
None NR
12 31 vs. 42
3 0 vs. 10
12 13 / 32 / 50
4 0/ 2.4/ 57
20 0 vs. 7
6 11 vs. 7
(p = NR)
(p = NR)
(p = NR)
(p = NR)
(p < 0.015)
(p = 0.003)
(p = NR)
(p = NR)
study conclusion with a 95% healing rate. While this study is promising for the use of nifedipine as an alternative to nitrate therapy for
chronic anal fissure, the extent of treatment effect is questionable
given the low fissure healing rate in the placebo arm.
Calcium Antagonists versus Sphincterotomy
Two studies have compared calcium channel blockade (oral and
ointment preparations) to lateral internal sphincterotomy in the
treatment of chronic anal fissure.(49, 50) (Table 20.3) While both
Calcium Channel antagonists versus Nitrates
Five studies have compared calcium channel antagonists to nitrate
therapy in patients with chronic anal fissure. (Table 20.3) Three
of these studies have used 2% diltiazem ointment in comparison
to 0.2% or 0.5% GTN administered over 6–8 weeks.(46–48) All
three studies report no difference in anal fissure healing between
the GTN or diltiazem treated groups. In all three studies, there
were more overall side effects and headaches in the nitrate treated
patients compared to the diltiazem treated patients. In the largest of the three studies, recurrence occurred sooner and more
frequently among patient receiving GTN compared to diltiazem.
(48) Overall, diltiazem ointment has equal efficacy to GTN ointment for anal fissure healing with fewer side effects, and possibly
a lower rate and longer interval to recurrence.
Two studies used nifedipine preparations for comparison with
GTN for the treatment of chronic anal fissure.(49, 50) In one study,
a 0.2% nifedipine ointment (49) was used while oral nifedipine
was used in the other.(50) Ezri et al. found the nifedipine ointment to be superior to the GTN ointment in healing anal fissure.
They also found a higher rate of overall side effects in the GTN
treated group. However, both treatment arms were found to have
a high recurrence rate over 12 months (31–42%). In contrast, the
oral nifedipine was equivalent to GTN ointment in fissure healing,
studies measure a high rate of fissure healing in patients undergoing sphincterotomy (95–100%), there is a wide range in the fissure
healing rate for patients receiving nifedipine treatment (16–97%).
In one study, oral nifedipine was used.(51) The authors report
a significant problem with patient compliance in this treatment
arm secondary to side effects, slow fissure healing, and minimal
symptomatic improvement. Overall 41% of patients in the oral
nifedipine group experienced these problems, and 70% withdrew
from the study. While these patients were analyzed on an intention to treat basis, the effect of oral nifedipine on fissure healing
may have been substantially decreased. In contrast, Katsinelos and
colleagues measured a high rate of fissure healing after treatment
with nifedipine ointment (97%) that was not significantly different from fissure healing after sphincterotomy (100%, p = 0.49).
(52) The increased treatment effect of nifedipine ointment may be
secondary to a higher dose that was used in this study compared to
others (0.5% vs. 0.2%). In addition, topical calcium channel antagonists have been proven more effective than oral preparations in
fissure healing and side effect profile.(53) Overall, these studies
suggest that oral calcium channel antagonists do not increase fissure healing rates but do increase side effects. However, increases
in ointment concentrations may increase treatment efficacy without a change in adverse side effects.
20
surgery and nonoperative therapy of anal fissure
Table 20.4 Randomized Controlled Trials of Botulinum Toxin for the Treatment of Chronic Anal Fissure.
Author/
Year
Number of
Patients
Treatment Groups
Fissure Healing (%)
Side Effects (%)
Follow-up
(months) Recurrence (%)
Maria
1998 (57)
Colak
2002 (61)
Siproudis
2003 (62)
Brisinda
1999 (64)
DeNardi
2006 (66)
Fruehauf
2006 (67)
Brisinda
2007 (65)
Mentes
2003 (71)
Iswariah
2005 (70)
Arroyo
2005 (69)
Note: B = Botox; IC = incontinence; BID = two times per day; NR = not reported; NS = not statistically significant; GTN = Glyceryl trinitrate; HA = Headache;
TID = three times per day; LIS = Lateral Internal sphincterotomy
a. Crossover after 2 months treatment.
In summary, topical calcium channel antagonists may be used
in the treatment of chronic anal fissure. They have similar efficacy
to nitrates with a lower occurrence of side effects. Topical preparations of nifedipine or diltiazem are preferred over oral preparations due to a higher fissure healing rate and fewer side effects
compared with oral administration. Sphincterotomy remains the
gold standard for healing of chronic anal fissure, but given the
chance for incontinence after surgery, topical calcium channel
antagonists are preferred for first line therapy.
30 0.4 ml saline vs. 20 U B
62 Lidocaine BID 4 wks vs. 50 U B
44 0.4 ml saline vs. 100 U Dysport
50 0.2%GTN BID 6 wks vs. 20 U B
30 0.2% GTN BID 8 wks vs. 20 U B
50 0.2% GTN BID 2 wks vs. 30 U B
100 0.2% GTN TID 8 wks vs. 30
101 LIS vs. 0.3U/kg BT (20U or
38 LIS vs. 20 U B
80 LIS vs. 25 U B
a
U B
30U) B
13 vs. 73 (p = 0.003)
21 vs. 71 (p = 0.006)
32 vs. 32 (p = NS)
a
60 vs. 96 (p = 0.005)
3 months: 67 vs. 47 (p = 0.51)
2 weeks: 52 vs. 24 (p < 0.05)
70 vs. 92 (p = 0.009)
98 vs. 74 (p < 0.001)
6 weeks: 86 vs. 41 (p = 0.004)
12 months: 93 vs. 45 (p < 0.001) IC: 7.5 vs. 5 (p = NS)
IC flatus: 3.3 overall 4 None
None 2 NR
Perianal
thrombosis: 9.1 vs. 18.2
Abscess: 13.6 vs. 4.5
GTN: 20% HA
BT: None
GTN: 20% HA
BT:None
26% overall
GTN: 48% HA
GTN: 34% HA
BT: 6% IC flatus
IC: 8 vs. 0 12 5 vs. 11
IC: no difference 6 10 vs. 53
have been performed to determine the BT dose with the highest
fissure healing rate and the least amount of complications.(55–59)
All these studies show that fissure healing rates are improved with
increasing BT doses. Botox doses as high as 40–50 units of have
been used in a single injection. Increasing doses do not lead to
higher complication rates but do lead to more significant decreases
in MARP from baseline.(57) This increased efficacy is secondary
to a dose dependent diffusion of the toxin through the IAS muscle.
Higher BT doses have a direct effect throughout the muscle whereas
3 9.1 vs. 13.6
(p = NS)
15 None
36 33 vs. 33
(p = NS)
3 NR
21 20 vs. 0
(p = NR)
(p = NR)
(p < 0.05)
36 7.5 vs. 55
(p < 0.001)
smaller BT doses demonstrate a gradient of paralysis through the
Botulinum toxin
Botulinum toxin (BT) is an exotoxin produced by the bacterium
Clostridium botulinum. BT has been used medically in the treatment
of multiple diseases in which there is muscular hypertonicity. Chronic
anal fissure is characterized by internal anal sphincter (IAS) hypertonia and has been treated with BT since 1993. The exact mechanism
of BT on internal anal sphincter relaxation is still unclear. In striated
muscle, BT binds to presynaptic nerve terminals and prevents the
release of acetylcholine, resulting in paralysis. However, in smooth
muscle, BT reduces the release of excitatory neurotransmitters from
sympathetic nerves and probably causes IAS relaxation through
sympathetic blockade.(54) Manometric studies demonstrate a sustained decrease in mean anal resting pressure (MARP) when BT is
injected into the internal anal sphincter. This sustained reduction in
muscle length.(58) Other factors which may lead to variations in
clinical response are differences in drug dilution volumes, number
of injection sites, presence or absence of antibodies, variations in
active drug, and susceptibility of target cells. Maria et al. examined
the role of BT injection site on fissure healing.(60) Their hypothesis
was that posterior injection of BT leads to impaired diffusion of
the toxin secondary to increased fibrosis around posterior fissures.
Indeed, they found that 20 units of Botox on either side of the anterior midline resulted in lower mean anal resting pressures as well as
higher fissure healing rates compared to 20 units of Botox administered on either side of the posterior midline. Results from these
studies show BT is safely administered in high doses (30–40 units
Botox) as initial therapy and may be more effective if administered
in the anterior rather than posterior midline.
MARP is in contrast to the short-lived relaxation seen in response to
GTN therapy. This longer period of IAS relaxation after BT injection
may lead to higher rates of chronic anal fissure healing secondary to
improved blood flow to the posterior commissure.
Multiple studies have been performed to determine the opti-
mal dose and method of delivery for BT to the IAS. Most studies
Botulinum Toxin versus Placebo
Three randomized studies have evaluated BT efficacy in com-
parison to a “placebo” treatment.(61–63) (Table 20.4). In two
studies, normal saline injections of a volume equal to that of
the toxin used, were injected into the IAS.(62, 63) In the third
20
improved outcomes in colon and rectal surgery
study, lidocaine ointment was applied twice daily and with bowel
movements for a 4 week period.(61) In two studies, there was a
significant difference in fissure healing between placebo and BT
treated patients (13–21% vs. 71–73%).(61, 63) In the third, there
was no measured difference in fissure healing between the two
groups (32%).(62) Maria et al. also reported a 25% posttreatment decrease in MARP from baseline in the toxin group but not
in the placebo group.(63) Reported side effects in these studies
were minimal with incontinence to flatus in one patient, perianal thrombosis in six and perianal abscess in four of 136 total
patients. The recurrence rate was not consistent among these
studies with reports of no recurrence compared to a high of 13%
in the BT treatment group after 4 months. The different findings
in these three studies which compare BT to placebo for chronic
anal fissure may be explained by methodological differences and
baseline differences in the study groups at randomization. In one
trial there were more men and higher maximal voluntary anal
squeeze pressures in the placebo group as compared to the BT
treated group.(63) This may have lead to a difference in treatment effect. Also, one trial was not able to be blinded secondary to the use of ointment in the placebo group and injection in
the toxin group.(61) It is unclear whether clinicians who were
grading fissure healing were blinded to randomized treatment
groups. Finally, the third study was stopped early before reaching the intended sample size because of newly published studies demonstrating BT efficacy in fissure healing. Despite these
methodological differences and group differences after randomization, these studies suggest that BT is superior to placebo in
the healing of chronic anal fissure.
Botulinum Toxin versus Nitrates
Four randomized trials have compared the efficacy of BT to GTN
ointment.(64–67) (Table 20.4) In each trial there were differences
in the length of treatment (2–8 weeks) and application frequency
(2–3 times per day) of GTN ointment. There were also differences
in the dose of BT used with two studies using 20 units of Botox
and the other two studies using 30 units. Two studies found a significant improvement in anal fissure healing for patients treated
with BT compared to 0.2% GTN ointment (92–96% vs. 60–70%).
(64, 65) A third study measured an advantage of GTN treatment
administered over 2 weeks compared to BT (52% vs. 24%).(67)
These findings are surprising given the previous studies which
show 4–8 weeks are needed to achieve fissure healing with GTN
treatment. In the fourth study, there was no difference in treatment efficacy between BT and GTN ointment administered over
8 weeks.(66) However, this is the smallest of the four studies and
may not have been adequately powered to measure a difference
in treatment efficacy. Patients treated with GTN ointment were
more likely to suffer adverse side effects (20–34% headache) in
comparison to BT treated patients (0–6% temporary incontinence to flatus). Fissure recurrence was more frequent in GTN
treated patients in one study (65) but not in another.(66) In a different study, long-term fissure recurrence after BT treatment was
42% after 42 months.(68) Overall, these studies show a benefit of
BT compared to GTN in terms of short term fissure healing and
adverse medication effects. Frequent fissure recurrence after GTN
and BT treatment has been observed.
In two studies of GTN versus BT treatment crossover was performed at 2 months.(64, 65) Patients who did not heal with their
initial treatment and accepted the alternative treatment were able to
achieve fissure healing with the alternative treatment In both studies,
patients who failed BT and then received GTN (8 patients), experienced fissure healing within 2 months. Twenty one patients who
failed GTN and then received BT achieved fissure healing within 2
months. These studies suggest that patients who fail initial therapy
with GTN or BT, can be successfully treated with an alternative medical therapy before surgical treatment is considered.
Botulinum Toxin versus Sphincterotomy
There are three randomized studies which compare outcomes
for patients receiving either BT or internal sphincterotomy (IS).
(69–71) (Table 20.4) In these studies, IS was superior to BT for
fissure healing (86–98% vs. 41–75%). While sphincterotomy is
usually avoided secondary to fears of incontinence, there was no
significant difference in continence scores in any of these four
studies. Incontinence after fissure treatment with either BT or
sphincterotomy was associated with lower mean anal resting
pressures after treatment and age >50 years.(69) Fissure recurrence was also more common in BT treated patients compared to
IS treated patients.(69, 70) Recurrences were seen 6–12 months
after fissure healing.(69) Recurrence was associated with certain
clinical and manometric risk factors. These include symptom
duration greater than 12 months, presence of a sentinel pile,
persistently elevated mean anal resting pressure and amount of
time slow wave and ultra slow waves are present on manometric
examination. Based on these studies, patients who are at high risk
of anal fissure recurrence should undergo IS as a first line therapy. In patients who are at high risk of incontinence after IS, the
first line therapy should be BT since healing can be achieved with
lower complications even if repeat injection is required.
Overall, BT injections can be used for the treatment of chronic
anal fissure with improved fissure healing rates compared to
placebo and GTN. Fissure healing may take longer after BT treatment when compared to fissure healing after IS, but is associated
with few complications. Patients at high risk of incontinence (age>
50 yrs, previous anorectal surgery, multiparous females, diagnosis
of inflammatory bowel disease) should be treated with BT before
IS. Anal fissure recurrences after BT treatment are common, but
can be treated with repeat BT injection without adverse effects.
SURGICAL THERAPY
While surgical treatment of chronic anal fissure has been employed
since the 19th century, improved pathophysiologic understanding in
the middle of the 20th century, led to the reintroduction of surgical
treatments. In 1964, Watts, Bennett and Goligher described stretching of the anal sphincter with finger dilation, and Eisenhammer
recommended sectioning the internal anal sphincter to reduce
sphincter resting pressure.(72, 73) Since their initial description,
anal dilation and sphincterotomy have been used in numerous
randomized controlled trials to determine the ideal surgical treatment for chronic anal fissure. Overall there is a clear benefit of
sphincterotomy compared to anal stretch for fissure healing and
postoperative incontinence. This has been confirmed in clinical trials as well as manometric evaluations. After sphincterotomy, mean
20
surgery and nonoperative therapy of anal fissure
anal resting pressure is permanently reduced in patients with anal
fissure who have been shown to have significantly elevated preoperative resting pressures compared to controls.(74) Yet, the initial
surgical techniques of Watt and Eisenhammer have been revised
with multiple studies comparing the efficacy of modified surgical
interventions on fissure healing, recurrence, anal resting pressure,
and treatment complications such as incontinence.
Anal Dilatation
Anal dilation has been used in three different forms for the treatment of chronic anal fissure. Gentle, graduated anal dilation
has been accomplished with standardized anal dilators (20–27
mm) which are increased in size over several weeks of treatment.
Anal dilation has also been achieved with a one time pneumatic
balloon dilation of the sphincter to 1.4 atmospheres. Finally, anal
dilation has been performed using anal stretch with 4–6 finger
dilation of the sphincter. All these techniques have been criticized
for the poorly controlled sphincter stretch that results in damage
to both the internal and external sphincter. The result of uncontrolled sphincter stretch can lead to high rates of incontinence
for both flatus and stool that may be permanent. In reality, each
of these forms of anal dilation lead to variable degrees of control
over the amount of sphincter stretch and thereby affect fissure
healing, recurrence, and incontinence rates differently.
The forceful anal stretch procedure has the least amount of
standardization on sphincter dilation. It has been compared to
the gold standard, internal anal sphincterotomy, in five randomized controlled trials.(75–79) Three of these studies found that
internal sphincterotomy was superior to anal stretch secondary to
higher fissure healing rates (90–97% vs. 70–71%) with significantly lower rates of incontinence (3.3–20% vs. 20–39%).(75–77)
The other two studies found an advantage in fissure healing rates
after anal stretch at 4 month follow-up with comparable rates of
fissure recurrence and incontinence.(77, 79) However, these two
studies have been criticized for high drop out rates, short followup, and question of inadequate sphincterotomy. Overall, internal
sphincterotomy is superior to forceful anal stretch for the surgical
treatment of chronic anal fissure.
Given previous criticisms, techniques for controlled anal stretch
have been developed. When graduated anal dilators are used over
several weeks, the effect on fissure healing is inconsequential and
not better than placebo.(80) The addition of heat to anal dilators
along with nitroglycerin ointment may lead to improved fissure
healing rates (94% at 12 months). (81) However, this was a small
study which has not been replicated. Controlled anal stretch
with increased dilation effect has been attempted with pneumatic balloon dilation. In a prospective clinical trial, Renzi and
colleagues measured the effect of anal balloon dilatation to 1.4
atmospheres over six minutes. In 33 patients, 94% healed within
5 weeks of treatment, 3% recurred over 12 months and 6% of
patients had transient incontinence. These treatment effects were
achieved with a measureable decrease in anal resting pressure
with no visible sphincter defect on endorectal ultrasound.(82)
This study was followed by a randomized controlled trial of 36
patients who received either pneumatic sphincter dilatation or
nitroglycerin ointment.(83) At 30 days, 95% of patient undergoing pneumatic sphincter dilation had healed fissures compared
to 40% of patients who received nitroglycerin ointment. While
local wound problems such hemorrhoid thrombosis occurred in
the short-term, there were no patients who complained of problems with continence after pneumatic dilation. In all, graduated
anal dilation is not more effective than placebo for the treatment
of chronic anal fissure, while pneumatic balloon dilation of the
sphincter may result in improved fissure recurrence and incontinence rates than those seen with forceful anal dilation. Further
studies of pneumatic balloon dilation are needed to see if it is in
fact comparable to internal sphincterotomy.
Sphincterotomy
Internal sphincterotomy has also been subjected to revisions in
technique. Initially, Eisenhammer described division of the external sphincter and then modified his technique to that of the internal sphincter at the posterior midline.(73) Overtime, it became
apparent that fissurectomy with posterior midline sphincterotomy resulted in a “keyhole deformity” or deep furrow in the
excision site which interfered with closure of the anal canal while
at rest.(84) This deformity lead to increased rates of incontinence
compared to lateral sphincterotomy with longer healing times.
(78) Posterior sphincterotomy has subsequently been abandoned
in favor of lateral internal sphincterotomy.
Lateral internal sphincterotomy has also been performed in an
open and closed fashion. The open technique involves a 1–2 cm
skin incision over the intersphincteric groove and lateral to the
anal canal.(85) The internal anal sphincter is then separated from
the external sphincter and mucosa up to the dentate line so that
it can be divided under direct vision. Closed internal sphincterotomy was first described by Notaras in 1969.(86) With this technique, an 11 blade scalpel is inserted through the anoderm into
the intersphincteric plane. While using a finger for guidance, the
surgeon rotates the blade 90 degrees and an internal sphincterotomy is performed upto the dentate line. Given the blind technique
of closed internal sphincterotomy, surgeons have questioned the
adequacy of sphincter division using this technique. In fact, closed
sphincterotomy has been compared to open sphincterotomy in
4 randomized controlled trials with 299 patients.(87–90) All four
studies found equivalent rates of fissure healing (90–100%), and
recurrence (0–10%). Incontinence occurred infrequently (4.1–
7.5%) and improved with time. Therefore, both open and closed
techniques have been shown through randomized controlled
trials to have equal outcomes.
Surgical treatment of chronic anal fissure can lead to variable
rates of incontinence to gas and liquids that can be temporary or
permanent. In an effort to reduce rates of incontinence after sphincterotomy, investigators have sought to determine the optimal length
of sphincterotomy which allows for fissure healing but minimizes
postoperative incontinence. Two randomized studies have examined the role of sphincterotomy length on fissure healing, recurrence, and incontinence. In these studies, limited sphincterotomy
to the fissure apex was compared to a full sphincterotomy to the
dentate line.(91–92) Fissure healing rates were similar (88–100%)
in both studies. In one study there was no fissure recurrence after
24 weeks of follow-up (91), and, in the other, there was a 13.2%
treatment failure rate in the limited sphincterotomy group.(92)
There were also short-term differences in incontinence between
20
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