الفهرس 
Embryology Of Rectum And Anal CanalOnly 14 pages are availabe for public view
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Abstract
The fistula is an abnormal communication between two epithelial lined surfaces; it is lined by granulation tissue that is why it persists. 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, ulcerative colitis, tuberculosis, actinomycosis, foreign body, lymphograuloma venereum and trauma.
The estimated incidence among population is about 1:10.000 and male to female ratio is of between 2:1 and 4:1.
In the standard classification of anal fistulae, the fistulae are classified into two groups; low level fistulae in which the internal opening below the anorectal ring, and high level fistulae in which the internal opening at or above the anorectal ring, but the most widely used classification is that of Parks’ in which the anal fistulae are classified into; intersphincteric fistulae in which there are simple and complicated, trans-sphincteric fistulae in which there are simple and complicated, suprasphincteric fistulae and extrasphincteric fistulae.
Diagnosis of anal fistula is by symptoms: purulent discharge, bleeding, diarrhea and pruritis, but if the orifice is occluded the pain is present and increases until the discharge erupts. Signs: external opening, induration along the track and internal opening may be identified by rectal examination or proctoscopy. Fistulography may be helpful but it was found inaccurate in about 84% of cases. Computerized tomography has no convincing evidence of improvement in management; anal ultrasonography is not yet widely used. The role of magnetic resonance imaging can accurately identify the internal opening reaching up to 85% and the abscesses in about 100% and if it is done in recurrent fistulae reduces further recurrence from 52% to 13%.
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, in surgical treatment many ingenious methods have been devised to preserve the external sphincter complex, the multiplicity of techniques reflects their relative lack of success. Fistulotomy and fistulectomy are sutable only for low anal fistulae, however fistulotomy is better. Fistulectomy by core out technique is suitable for high anal fistulae but not for recurrent or more complex fistulae. Rerouting method is technically difficult and necessitates more than one setting. Seton technique whether two-stage fistulotomy or cutting seton are equally have recurrence rate of about 8% and partial loss of continence of about 66% in treatment of high anal fistulae, however, 44% may heal spontaneously after removal of loose seton with partial loss of continence of about 17%. Advancement and core out fistulectomy has a recurrence rate of about 7% and partial loss of continence of about 8%, but it is technically difficult and the flap may undergo necrosis. Fibrin glue may be used in high fistulae with success rate of about 70% and recurrent fistulae with success rate of about 60%, it has no advantage over fistulotomy in simple fistulae, but it healed more complex fistulae than other techniques and with higher patients satisfaction. Surgisis (Anal Fistula Plug) is a new paradigm in the treatment of anal fistulas, it is an innovative, yet simple treatment for a notoriously difficult condition, which traditionally requires surgical intervention, the plug is well tolerated by patients and early clinical results are showing significant improvement without cutting the sphincter muscle. Carbon dioxide laser ablation therapy successfully treats perianal fistula; many fistulas are completely healed and others are converted into a single, minimally draining fistula with this well-tolerated outpatient procedure.