الفهرس 
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Abstract
Summary
Fistula-in- ano is a track, lined by granulation tissue
that connects deeply in the anal canal or rectum and
superficially on the skin around the anus. The
cryptoglandular hypothesis is the most accepted theory in the
pathogenesis of the anal fistulae, also there are some other
causes e.g. Crohn’s disease, tuberculosis, actinomycosis,
foreign body and trauma.
The estimated incidence is about 5.6 per 100.000 in
women and 12.3 per 100.000 in men. The disease occurs
predominantly in the third and fourth decade of life.
In the standard classification of anal fistulae, the fistula
is classified into two groups; low level and high level
fistulae, but the most widely used classification is that of
Parks’ in which the anal fistulae are classified into; intersphincteric,
trans-sphincteric, supra-sphincteric and extrasphincteric
fistulae.
Perianal fistulae present with purulent discharge
around the anus, bleeding, diarrhea and pruritis, but if the
orifice is occluded the pain is present and increases until the
discharge erupts.
Fistulography can reveal the depth and the branches of
the tracks. However, the injection of dye under high pressure
carries the risk of sepsis dissemination.
With three dimensions endoanal ultrasound, fistula
tract is visualized as tube-like hypoechoic lesion, when
hydrogen peroxide 3% is introduced into the fistula tract it
generates small air bubbles, the ultrasonographic appearance
is changed into bright hyperechoic lesion. By comparing the
two images, the fistula tract and its extensions could be
identified and discriminated from previous scars.
Magnetic resonance imaging is accurate in identifying
fistula, as it was shown that fistula surgery guided by MRI
reduced the recurrence of anal fistula by 75% and therefore,
recommended in all patients presenting with recurrent fistula.
Performing MRI with contrast allows discrimination of
fistulous tracts from adjacent structures.
Treatment of anal fistulae is surgical except in those
circumstances of unusual aetiology such as Crohn’s disease
or tuberculosis which can be treated by treatment of the
cause. Surgical strategies to treat anal fistula tend to be
guided by their degree of complexity and their underlying
aetiology.
For simple low fistula, fistulotomy and lay open may
be enough. But for high anal fistula, seton fistulotomy
provides good results. Fistulectomy by core out technique is
suitable for high anal fistula but not for recurrent or more
complex fistula. Rerouting method has the benefit of minimal
loss of muscle tissue but it is technically difficult and
necessitates more than one sitting.
Advancement flap is an effective procedure for
complex anal fistulae with good functional results and
minimal or no disturbance of continence due to avoiding any
sphincter division.
Treatment of perianal fistula using fibrin glue is safe,
simple, and associated with early return to normal activity.
Although moderately successful, it may preclude extensive
surgery in more than one-half of these patients.
Anal fistula plug is a new modality in the treatment of
anal fistulae. The plug is cone shaped and when placed in the
fistula tract it is proposed to serve as a bioscaffold for native
tissue regeneration and hence occlude the fistulous tract. The
technique has appeal for its simplicity, avoidance of open
wounds, and avoidance of sphincter injury and preservation
of continence with avoidance of soiling.