anatomy of the anal canal; causes, examination, classification and management of fistula in ano

1. FISTULA IN ANO Dr. Rishabh Handa

2. ANAL CANAL ANATOMY
•Anatomic anal canal extends from the dentate
(pectinate) line to the anal verge.
•Dentate(pectinate) line marks the transition point
between columnar rectal mucosa and squamous
anoderm.

3. •Anal transition zone:
•Junction between the columnar epithelium above
and the squamous epithelium below.
•Variable in length ; often extends about 1 cm
proximal to the dentate line
•can be as far as 15 cm proximal to the dentate

4. •Dentate line is surrounded by longitudinal mucosal
folds, known as the columns of Morgagni.
•Lower ends of the columns form small crescentic folds,
called anal valves, between which lie small recesses
known as anal sinuses.
•Anal glands open into small depressions, anal crypts,

6. •Surgical anal canal
•begins at the anorectal junction and
terminates at the anal verge.
•measures 2 to 4 cm in length
•longer in men than in women.

7. •Epithelium below the dentate line:
•non-keratinized, stratified squamous epithelium
•lacks sweat and sebaceous glands and hair
follicles

8. •contains numerous somatic sensory nerve
endings conveying sensations of touch, pain
and temperature
•extends down to the intersphincteric groove,
a palpable depression at the lower border of
the internal sphincter.

9. •Below the intersphincteric groove:
•hair-bearing keratinizing, stratified squamous
epithelium, which is continuous with the
perianal skin.

10. •Internal anal sphincter:
•Specialized, white, thickened terminal part of the
inner circular muscle of the large bowel
•Extent: from anorectal junction to just above the
anal verge
•Tonically contracted at rest but relaxes as a
consequence of reflex activity, predominantly during
defecation

11. •External anal sphincter:
•Forms the bulk of the anal sphincter complex
•Oval tube of striated muscle
•Upper part : surrounds the internal anal sphincter
•Lowermost part : encircles the anal canal inferior
to the internal anal sphincter
•Is tonically contracted at rest (the postural reflex)

12. Inner circular
muscle

13. DEVELOPMENT OF ANAL CANAL
•Fusion of Post-allantoic gut (upper) with the
Proctodeum(lower part)
•Pectinate or Dentate line is the junction of these
two.

14. ANORECTAL SEPSIS AND
CRYPTOGLANDULAR ABSCESS
Cause : infections of the anal glands in the
intersphincteric plane
Their ducts traverse the internal sphincter
Empty into the anal crypts at the level of the dentate
line.
Formation of an abscess

15. •Perianal space : surrounds the anus and laterally
becomes continuous with the fat of the buttocks.
•Intersphincteric space :
•separates the internal and external anal sphincters
•continuous with the perianal space distally and
extends cephalad into the rectal wall.

16. •Ischiorectal space (ischiorectal fossa) :
located lateral and posterior to the anus
bounded medially by the external sphincter,
laterally by the ischium,
superiorly by the levator ani, and
inferiorly by the transverse septum
Contents : inferior rectal vessels and lymphatics

17. Deep postanal space : two ischiorectal spaces
connect posteriorly above the anococcygeal
ligament but below the levator ani muscle.
Supralevator spaces : lie above the levator ani on
either side of the rectum and communicate
posteriorly.
Anatomy of spaces - influences the location and
spread of infection

18. PERIANORECTAL SPACES (ANTERIOR VIEW)

19. PERIANORECTAL SPACES (LATERAL VIEW)

20. PATHWAYS OF ANORECTAL INFECTION IN PERIANAL SPACES

21. FISTULA IN ANO
•Drainage of an anorectal abscess results in cure for
about 50% of patients.
•The remaining 50% develop a persistent fistula in
ano.
•The fistula usually originates in the infected crypt
(internal opening) and tracks to the external opening,

22. Causes:
•Majority - cryptoglandular in origin,
•Others :
•Crohn’s disease,
•trauma,
•malignancy,
•radiation, or
•unusual infections (tuberculosis, actinomycosis, and
chlamydia)
A complex, recurrent, or nonhealing fistula should
raise the suspicion of one of these diagnoses.

23. •Fistula tracts are fibrous inflammatory tubes
with a diameter of 3 to 7 mm.
•They are lined with infected granulation tissue.

24. HISTORY
•Most patients - previous history of anorectal
suppuration
•Patient usually presents with
•complaints of intermittent or persistent purulent or
serosanguinous drainage from an external opening

25. •Symptoms classically consist of:
•buildup of pain,
•slight fever,
•pain on defecation followed by mucopurulent
drainage and abatement of the pain
•Pruritus - because of skin irritation associated with
the chronic discharge.

26. EXAMINATION
•Many fistulas may be palpated during a careful digital
rectal examination.
•Essential points that should be obtained from a
clinical examination include
•the identification of the external and internal

27. •the course of the primary and any secondary
tracts
•an assessment for the presence of an
underlying complicating disease
•Using an anoscope, systematic inspection and
palpation can define most of these
characteristics.

28. •The gentle use of malleable anorectal probes and
crypt hooks can help delineate the fistula by passing
via the internal or external opening.
•It is important not to force the passage of the probe
because the development of false tracts can
complicate evaluation and management.

29. •Secondary tracts may be present when induration is
palpated or asymmetry is noted between the right
and left sides of the anorectum.
•External opening - identified as a small pit
surrounded by scar or granulation tissue.
•Active seropurulent drainage may be present.

30. •Intersphincteric tracts usually open externally close
to the anal verge; trans-sphincteric and other
complicated tracts open farther away.
•Occasionally, the external opening may be localized
inside the anal canal or at the distal end of a fissure.

31. •Several external openings may be present because of
multiple complex fistula tracts; this condition is known
as “watering-pot perineum.”
•The internal opening may be felt as an indurated
nodule, most often at the dentate line.
•This is consistent with the cryptoglandular theory of
anorectal sepsis.

32. GOODSALL’S RULE
•If a line is drawn transversely across the anus, fistulas
with an external opening anterior to the line connect to
the internal opening by a short, radial tract.
•Fistulas with an external opening posteriorly track in a
curvilinear fashion to the posterior midline.

33. Exception : if an anterior external opening is
greater than 3 cm from the anal margin. Such
fistulas usually track to the posterior midline.

34. GOODSALL’S RULE TO IDENTIFY THE INTERNAL OPENING OF
FISTULAS IN ANO.

35. PARK’S CLASSIFICATION OF ANAL
FISTULAS
•Intersphincteric (the most common): The fistula
track is confined to the intersphincteric plane.
•Transsphincteric: The fistula connects the
intersphincteric plane with the ischiorectal fossa by
perforating the external sphincter.
•Suprasphincteric: Similar to transsphincteric, but the
track loops over the external sphincter and
perforates the levator ani.
•Extrasphincteric: The track passes from the rectum
to perineal skin, completely external to the

36. A, INTERSPHINCTERIC:
1. SIMPLE.
2. HIGH BLIND TRACT. THERE IS A HIGH EXTENSION OF THE FISTULA BETWEEN THE INTERNAL SPHINCTER AND THE
SPHINCTER AND THE LONGITUDINAL MUSCLE OF THE UPPER ANAL CANAL.
3. HIGH TRACT WITH RECTAL OPENING.
4. HIGH INTERSPHINCTERIC FISTULA WITHOUT A PERINEAL OPENING. THERE MAY OR MAY NOT BE A RECTAL OPENING.

37. B. TRANSSPHINCTERIC: THE FISTULA TRACT PASSES FROM THE INTERSPHINCTERIC PLANE
THROUGH THE EXTERNAL SPHINCTER MUSCLE.
1. UNCOMPLICATED.
2. HIGH BLIND TRACT. THE UPPER TRACT EXTENSION MAY GO TO THE APEX OF THE
OF THE ISCHIORECTAL FOSSA OR EXTEND HIGHER THROUGH THE LEVATOR MUSCULATURE
INTO THE PELVIC CAVITY.

38. C. SUPRASPHINCTERIC: THERE IS AN UPWARD EXTENSION OF THE FISTULA TRACT IN
THE INTERSPHINCTERIC PLANE. THE TRACT THEN PASSES ABOVE THE LEVEL OF THE
PUBORECTALIS MUSCLE AND CONTINUES DOWNWARD THROUGH THE ISCHIORECTAL
FOSSA TO THE PERIANAL AREA.
D. EXTRASPHINCTERIC: THERE IS A TRACT THAT PASSES FROM THE SKIN OF THE
PERINEUM THROUGH THE ISCHIORECTAL FOSSA AND THE LEVATOR MUSCLES
BEFORE ENTERING THE RECTAL WALL.

39. SPECIAL STUDIES
Sigmoidoscopy and Colonoscopy
•Sigmoidoscopy should be performed in all patients with
anorectal fistulas.
•The presence of associated pathology such as neoplasms,
inflammatory bowel disease, or associated secondary tracts
in the rectum must be sought.
•Such findings may dictate the need for full colonoscopic

40. Fistulography
•May be warranted in patients with
•recurrent fistulas or
•when a prior procedure has failed to identify the
internal opening.
•Technique: the external opening is cannulated with a
small-caliber tube and contrast material is injected
under minimal pressure while films are taken in

41. •May be useful in
•identifying unsuspected pathology,
•planning surgical management, and
•demonstrating anatomic relationships.
•However it has been found to be unreliable
compared with operative findings

42. Anorectal Ultrasonography
•Can delineate the muscular anatomy of the anal
sphincters in relation to an abscess or a fistula.
•Most commonly- performed with the use of a 360-
degree rotating probe using a 7- , 10-, or 13-MHz
transducer with a water-filled sonolucent plastic cone
over the transducer.
•Fistula tracts and abscesses appear as hypoechoic
defects within the muscular elements of the anal canal.

43. A. TRANSANAL ULTRASOUND PROBE (TYPE 1850; BRÜEL AND KJAER,
NAERUM, DENMARK). B, THE ROTATING TRANSDUCER IS COVERED BY A
HARD PLASTIC SONOLUCENT CONE, WHICH IS THEN FILLED WITH WATER
TO PROVIDE AN ACOUSTIC INTERPHASE.

46. •The internal opening is not distinctly identified.
•Although generally accurate in the localization of
abscesses and fistula tracts, primary superficial,
extrasphincteric, and suprasphincteric tracts or
secondary supralevator or infralevator tracts may be
missed.

47. •Hydrogen peroxide - as an image enhancer ; safe,
effective, and sometimes helpful in the detection of these
complex fistulas
•Additionally, three-dimensional endoanal
ultrasonography is now reliable and accurate in the
diagnosis of fistula-in-ano with or without hydrogen
peroxide enhancement.

48. A. TRANSSPHINCTERIC
HYPOECHOGENIC TRACT
EXTENDING TOWARD THE
POSTERIOR MIDLINE. THE
TRACT IS ENHANCED AS
HYDROGEN PEROXIDE IS
INJECTED INTO THE EXTERNAL
OPENING.
B. COMPLEX FISTULA TRACT
AND COLLECTIONS AS SEEN
WITHOUT (1) AND WITH (2)
HYDROGEN PEROXIDE
ENHANCEMENT. HYDROGEN
PEROXIDE ENHANCEMENT
ALLOWED FOR A MORE
PRECISE DELINEATION OF THE
TRACTS IN ADDITION TO A
RIGHT-SIDED EXTENSION OF
THE TRACT.

49. Magnetic Resonance Imaging
•5% to 15% of complex fistulas are often associated
with recurrent fistulas and fistulas associated with
underlying Crohn disease.
•MRI is helpful especially in these complex fistulas in
•identification of fistulous tracks,
•secondary extensions, and
•internal openings.

50. •Combining MRI with endoanal ultrasonography
and an examination under anesthesia may
enhance the accuracy of these tests in
determining fistula anatomy.

51. T2-WEIGHTED MR IMAGE SHOWING THE NORMAL MALE ANATOMY OF THE
PERINEUM AT THE LEVEL OF THE MID ANAL CANAL

52. T2-WEIGHTED MR IMAGE SHOWING THE NORMAL FEMALE ANATOMY OF THE
PERINEUM AT THE LEVEL OF THE PROXIMAL HALF OF THE ANAL CANAL

53. AXIAL T2-WEIGHTED MR IMAGE OF THE MALE PERINEUM SHOWS THE
ANAL CLOCK DIAGRAM USED TO CORRECTLY LOCATE ANAL FISTULAS
WITH RESPECT TO THE ANAL CANAL

54. AXIAL CONTRAST-ENHANCED FAT-SUPPRESSED T1-WEIGHTED MR
IMAGE SHOWS THE LEFT INTERSPHINCTERIC FISTULA (ARROW)
BOUNDED BY THE EXTERNAL SPHINCTER WITHOUT A SECONDARY
FISTULOUS TRACK OR ABSCESS.

55. CORONAL CONTRAST-ENHANCED FAT-SUPPRESSED T1-WEIGHTED MR
IMAGE SHOWS THE HIGHLY ENHANCING INTERSPHINCTERIC FISTULA
(ARROW) CONFINED BY THE EXTERNAL SPHINCTER.

56. AXIAL T2-WEIGHTED MR IMAGE SHOWS THE HIGH-SIGNAL-INTENSITY FLUID
COLLECTION ALONG THE RIGHT POSTEROLATERAL ASPECT OF THE ANAL CANAL
(ARROW).
AXIAL CONTRAST-ENHANCED FAT-SUPPRESSED T1-WEIGHTED MR IMAGE SHOWS
THE ABSCESS IN THE RIGHT POSTEROLATERAL ASPECT OF THE
INTERSPHINCTERIC SPACE (ARROWHEAD), BOUNDED BY THE EXTERNAL
SPHINCTER.

57. CORONAL CONTRAST-ENHANCED FAT-SUPPRESSED T1-WEIGHTED MR IMAGE
SHOWS THE RIGHT INTERSPHINCTERIC ABSCESS (ARROW) WITHOUT A
FISTULOUS TRACK OR ABSCESS IN THE RIGHT ISCHIORECTAL FOSSA.

58. CORONAL CONTRAST-ENHANCED FAT-SUPPRESSED T1-WEIGHTED MR IMAGE
SHOWS THE HIGHLY ENHANCING TRANSSPHINCTERIC FISTULA (ARROW)
FROM THE DENTATE LINE TO THE SKIN, PASSING THROUGH THE ISCHIOANAL
FOSSA AND PIERCING THE EXTERNAL SPHINCTER.

59. AXIAL CONTRAST-ENHANCED FAT-SUPPRESSED T1-
WEIGHTED MR IMAGE SHOWS THE LEFT SUPRALEVATOR
ABSCESS WITH INFLAMMATORY CHANGES IN THE LEFT
INTERNAL OBTURATOR MUSCLE (ARROWS).

60. Computed Tomography
•Role of CT is limited to the
•assessment of associated pelvic pathology in
patients with supralevator abscesses and
•in patients with some complex anal fistulas.

61. Anorectal Manometry
•Manometry can assist in identifying patients at
the greatest risk for postoperative incontinence.
•Surgical management can be tailored
accordingly, improving clinical and functional
outcome.

62. Fistuloscopy
•Anorectal fistuloscopy using flexible ureteroscopes
has been described.
•Potentially useful intraoperative technique used to
identify primary fistula openings, multiple or complex
tracts, and iatrogenic tracts.
•Modified flexible ureteroscopes are in the early
developmental stages.
•May significantly improve the outcomes of complex
fistula diagnosis and treatment in future.

63. TREATMENT
•Once diagnosed, patients with anorectal fistulas
should undergo surgical treatment. Anorectal fistulas
rarely heal spontaneously.
•The three basic surgical techniques for the treatment
of anorectal fistulas are
•fistulotomy
•use of a seton
•endorectal advancement flaps

64. •The use of fistulectomy is not recommended except
when it is necessary to provide histologic material.
•Position : prone jackknife position with the
buttocks taped apart.
•Anaesthesia : General, regional, or local anesthesia
with intravenous sedation should be selected on the
basis of individual patient characteristics

65. FISTULOTOMY
•Most anorectal fistulas may be adequately treated by
the classic laying-open technique or fistulotomy.
•Recurrence rates are low, and risks for continence
disturbances are minimal.

66. •Technique:
Fistula probe passed via the external opening,
along the tract, and through the internal
opening.
With the probe in place, the relationship of the
fistulous tract to the external sphincter muscle
can be determined.
If the tract lies distal to the majority of the
external muscle, then cautery is used to lay it

67. Secondary tracts should be drained through the
fistulotomy incision after all tracts have been
curetted.
Marsupialization with a running continuous
absorbable suture (associated with faster
healing)

68. •In patients with otherwise normal continence -
•the perianal skin,
•anal epithelium,
•a portion of the internal anal sphincter, and
•a few fibers of subcutaneous external sphincter
may be divided with minimal risk of incontinence.

69. •In women with anterior fistulas, such a
fistulotomy is associated with an unacceptably
high risk of incontinence because of the intrinsic
thin nature of the sphincter mechanism in this
area.
•Therefore, sphincter-preserving techniques
should be used in the treatment of anterior

70. LIFT (ligation of the intersphincteric fistula
tract)
•Novel sphincter-preserving method for fistula
closure.
Involves
•making an incision in the intersphincteric groove
•dissection between the sphincter muscles
•identification of the fistula tract

71. •Fistula probe is left in situ during this time to
facilitate identification of the tract.
•The fistula tract is then dissected free and the probe
removed.
•Next, the fistula tract is divided and ligated.

72. •The internal opening is closed with absorbable
suture and the external opening curetted and left
open to drain.
•Initial retrospective studies show this procedure
has a success rate similar to other sphincter-
preserving procedures, between 57% and 82%.

73. VIDEO-ASSISTED ANAL FISTULA
TREATMENT (VAAFT)
•Novel minimally invasive and sphincter-saving
technique for treating complex fistulas.
•Key steps are
•Visualization of the fistula tract using the
fistuloscope,
•Correct localization of the internal fistula opening

74. •Diagnostic fistuloscopy under irrigation followed by
•Operative phase of fulguration of the fistula tract
•Closure of the internal opening using a stapler or
cutaneous-mucosal flap and
•Suture reinforcement with fibrin thrombin glue

75. Advantages:
•Non Invasive, less pain, early recovery
•Helps to identify any possible secondary tracts or
chronic abscesses
•Sphincter saving
•Can be used again in case of failure

76. •Very Low risk of incontinence
•Good for complex deep seated abscesses and
fistulas especially Crohn’s Fistulas
•Can be combined with any other technique like
Seton and standard open surgical Method by
being able to directly visualize and reach high
internal opening

79. SETON MANAGEMENT
•Seton is derived from the Latin word seta, meaning
“bristle.”
•Refers to any foreign material that can be inserted
into the fistula tract to encircle the sphincter muscles.
•These materials may include
•Silk, Penrose drains,
•Silastic vessel loops, rubber bands,
•nylon or polypropylene, and
•braided steel wire.

80. Setons are placed by
securing the selected
material to the end of a
fistula probe after the
probe has been passed
through the internal
opening

81. SETON PLACEMENT. A, IF THE PRIMARY OPENING CANNOT BE IDENTIFIED BY GENTLE
PROBING ALONG THE DENTATE LINE, METHYLENE BLUE PLUS PEROXIDE INJECTIONS MAY
BETTER DELINEATE THE INTERNAL FISTULA SOURCE. B, A PROBE IS PASSED FROM THE
PRIMARY TO THE SECONDARY OPENINGS AND THE SKIN IS INCISED TO REVEAL THE TRACT
AND INTERPOSED SPHINCTER MUSCLE. C, AN ELASTIC CUTTING SETON CAN BE PLACED
WHEN GENEROUS MUSCLE REQUIRES DIVISION. D, THE SETON IS TIGHTENED IN THE
OPERATING ROOM AND AGAIN ONCE OR TWICE IN THE OFFICE TO ALLOW FOR FIBROSIS
AND GRADUAL SPHINCTER TRANSECTION.

82. Setons are useful in the management of complex
anorectal fistulas where there is an appreciable risk
of incontinence or poor healing; such cases include
patients with
•Crohn disease,
•immunocompromised and incontinent patients,
•patients with chronic diarrheal states, and
•anterior fistulas in women.

83. Cutting setons –
•Consist of a suture or a rubber band that is placed
through the fistula and intermittently tightened in
the opd.
•Tightening the seton results in fibrosis and gradual
division of the sphincter, thus eliminating the fistula
while maintaining continuity of the sphincter.

84. Noncutting seton –
•Soft plastic drain (often a vessel loop) placed in the
fistula to maintain drainage.
•The fistula tract may subsequently be laid open with
less risk of incontinence because scarring prevents
retraction of the sphincter.

85. Marking seton:
•Useful when it is difficult to determine the amount
of muscle the fistula tract crosses.
•Encircling the tract with a seton allows the surgeon
to assess the amount of muscle, particularly the
puborectalis, once the patient is awake.
•If adequate muscle is present above the fistula
tract, a fistulotomy may be performed without
significant risk for incontinence.

86. Draining seton :
•Traverses a fistula tract to provide long-term
drainage of a septic process.
•May be used as a bridge to definitive surgical
therapy or be left in place for long periods.
•Epithelialization of the tract prevents recurring
abscesses.
•Particularly useful in the management of complex
fistulas associated with Crohn disease.

87. Staging seton:
•The most superficial portion of the fistula tract is
divided.
•The seton is placed through that portion of the fistula
tract that traverses the sphincter, thus encircling the
muscle.
•This portion of the tract is divided as a second
procedure once adequate fibrosis occurs (usually 8

88. •A “high” fistula may be converted to a “low”
fistula by dividing only the proximal portion of
the tract, leaving the distal tract encircled with
a seton for division at a later date.

89. ANORECTAL ADVANCEMENT FLAPS
•Advancement flaps consist of
•mucosa,
•submucosa, and
•part of the internal sphincter

90. Underlying fistula tract is debrided
internal opening is sutured at the level of the
muscle
edge of the elevated flap containing the
internal
opening is excised
flap is advanced and sutured over the internal

91. A. ANORECTAL ADVANCEMENT FLAP FOR CLOSURE OF THE INTERNAL OPENING IN
THE TREATMENT OF PERIANAL FISTULAS. THE BASE OF THE FLAP SHOULD BE
WIDER THAN THE APEX. B. WITH THE FLAP ELEVATED, THE INTERNAL OPENING IS
DEBRIDED AND CLOSED WITH A SUTURE. C. THE APEX OF THE FLAP IS ADVANCED
AND SUTURED OVER THE DEFECT.

92. •Advantages:
•one-stage procedure,
•quicker healing,
•limited damage to the underlying sphincter,
and
•minimal risk of anal canal deformity.

93. FIBRIN GLUE
•A prepared mixture of fibrinogen and thrombin
is injected into the fistula tract after it has been
curetted.
•The resulting coagulum plugs the fistula tract.

94. •Alternative mode of treatment in complex cases
for which standard treatment has failed.
•Advantages: safety, ease of application, and
low risk of sphincter injury.

95. FISTULA PLUG
•Cone-shaped plug created from a bio-
absorbable xenograft made of lyophilized porcine
intestinal submucosa.
•Use : for high trans sphincteric fistulas

96. •Material
•has inherent resistance to infection,
•no foreign body or giant cell reaction,
•becomes repopulated with host cell tissue
during a period of 3 months.

97. •The fistula plug is inserted into the primary
opening of the fistula and secured into place
with one or two interrupted stitches.
•Advantages:
•preserves anal function
•associated with a low morbidity

98. POSTOPERATIVE CARE
•High-fiber diet
•No bowel confinement regimen for simple conditions;
Recommended for complex procedures, but it is of
questionable value.
•Sitz baths - for perianal hygiene and comfort

99. •More complex procedures may require inpatient
status for pain management and wound care.
•Wound healing after fistulotomy usually takes 4 to 8
weeks.
•Patients with an anorectal abscess - close follow up
for possible fistula development.

100. COMPLICATIONS (AFTER SURGICAL
INTERVENTION)
•Urinary retention - most common complication,
occurring in up to 25% of patients.
•Other complications include
•hemorrhage,
•acute external thrombosed hemorrhoids,

101. •cellulitis,
•fecal impaction,
•stricture,
•rectovaginal fistula,
•incontinence,
•recurrence.
•Local wound problems

102. SPECIAL CONSIDERATIONS
CROHN DISEASE
•Manifests with perianal or rectal symptoms in one-
third of patients
•More aggressive natural history, with many due to
anorectal sepsis and fistula.
•Anorectal abscess - should be treated with prompt

103. •Long-term catheter drainage
•safe and effective and
•may prevent or delay recurrence and the
subsequent need for proctectomy.
•In general, treatment modalities should be
conservative.

104. •Simple fistula in a patient with a normal rectum : treated
by primary fistulotomy with good outcome and
satisfactory healing rates.
•Complex fistulas in patients with active rectal Crohn
disease :
•prolonged drainage to achieve long-term palliation
•in selected cases, rectal advancement flaps may be

105. •Monoclonal antibody to tumor necrosis factor (TNF-
α) - Infliximab (Remicade) is used for the treatment
of patients with fistulizing Crohn disease.
•Duration of response is short-lived; repeat
treatment or chronic use may be required for a long-
term beneficial effect.

106. FISTULA IN INFANCY
•Occurs almost exclusively in otherwise healthy boys
younger than 2 years of age.
•Cause –
•congenital abnormality of the anal glands with
abnormally deep and thick crypts of Morgagni.

107. •Treatment:
•Simple fistulotomy
•Concomitant cryptotomy has been
recommended by some to decrease the
likelihood of recurrence.

108. ANORECTAL SEPSIS AND FISTULA IN HIV
DISEASE
•Estimated frequency of anorectal disease in HIV-
positive population - 6% to 34%.
•Factors associated with poor wound healing in HIV
positive patients
•Decreased CD4+ count
•presence of an acquired immunodeficiency
syndrome

109. •Simple fistulas : Fistulotomy
•Complex fistulas and patients with risk factors
for poor healing : the liberal use of draining
setons is recommended for symptomatic relief.

110. ANORECTAL COMPLICATIONS IN PATIENTS
WITH LEUKEMIA
•Rare but potentially life-threatening problem.
•In general, surgical treatment of anorectal
sepsis in uncontrolled acute leukemia has been
avoided because of the fear that the septic
process would spread and wound healing would
be impaired.
•Additional precautionary measures included no
rectal examinations, no instrumentation, and
no enemas.

111. MALIGNANT TRANSFORMATION IN CHRONIC
ANAL FISTULA
•Carcinoma arising in anorectal fistulas in patients
with Crohn disease has been reported; the estimated
incidence is 0.7%.
•Diagnosis: Deep biopsy samples, careful histologic
examination of atypical cells obtained from ductal
structures.
•Treatment: Resection with either wide local excision
or abdominoperineal resection

112. THANK
YOU