FISTULA IN ANO
WHEN TO SUSPECT/RECOGNIZE?
When a patient presents with a discharging opening gin the perianal region, on e should suspect a fistula in ano
INTRODUCTION:
A fistula is an abnormal communication between two epithelial surfaces.
DEFINTION:
By definition a fistula in ano is a communication between the anal canal and skin by a tract which may be straight and simple or complex with ramifications or a horse shoe tract involving the right and / or left halves. The discharge may be pus, fecal matter, flatus or serosanguinous.
Fistula are classified as low or high
Based upon their relationship to the anal sphincter complex, anal fistulas are categorized into:
1. Intersphincteric
2. Trans sphincteric
3. Supra sphincteric
4. Extra sphincteric
Treatment options are based upon these classifications
INCIDENCE:
Indian incidence is not documented
DIFFERENTIAL DIAGNOSIS:
Furunculosis
Crohn’s disease
Pilonidal sinus
Tuberculosis
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Actimycosis
Lymphogranuloma venereum
Granuloma inguinale
Perianal abcess
PREVENTION:
Adequate drainage of anorectal abscesses may prevent fistula formation
Predisposing causes
1. Crohn’s disease
2. Malignancy
3. Chlamydia
In the presence of a complex, recurrent, non healing fistula these should be suspected.
COUSELLING:
Surgical treatment alone offers permanent cure. So patients should be counseled for early surgey when it is a simple fistula so that it does not become complex.
OPTIMAL DIAGNOSTIC CRITERIA:
SITUATION 1:
CLINICAL DIAGNOSIS:
Patients with anal fistula commonly present with complaints of
 Discharge from external or internal opening, the external opening may be single or multiple
 Pain
 Swelling
 Fever
The presentation may be acute when there is acute perianal sepsis
A chronic anal fistula presents with periodic exacerbation and pus discharging openings around the anus per rectal exam and proctoscopy should be done to visualize both the internal and external openings. This may be adequate for a straight low tract.
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INVESTIGATIONS:
Fistulogram may be done when branching is suspected, in recurrent fistulae and when internal opening is not appreciable.
Examination under anesthesia
Probe test, caution may cause now internal opening
Injection technique is useful in delineating the tract
Biopsy when specific cause is anticipated
Barium enema – when co existing disease is suspected
Blood sugar – to r/o diabetes mellitus
Complete blood count
Urine r/m
X ray chest – to rule out TB
TREATMENT:
Simple low fistulae can be managed in a secondary hospital where a surgeon is available
SURGICAL PROCEDURES:
Surgical options are dictated by the type of fistula. Aim is to drain the septic focus and remove the fistula with minimal injury to the sphincter complex
Fistulotomy
Fistulectomy
Seton
Combination of the above:
Fistulotomy (of superficial position), with seton division (of the cephalad position)
Staged procedures may be required in high anal fistulae
Fistula presenting as perianal abscess would require drainage, analgesics and antibiotics followed subsequently by a definitive procedure
Fistulotomy and curettage / Fistulectomy – low anal fistula
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Trans sphincteric fistula that involve =<30 percent of sphincteric muscle – sphincteromy without risk of incontinence High Trans sphincteric fistulas – seton placement REFERRAL CRITERIA: Complex/recurrent/high anal fistulae may need referral to a higher centre for adequate investigation and management. Colostomy and staged procedure may be required. Co existing conditions like rectal cancers, Crohn’s disease, TB fistulae, HIV infection require referral SOP: In patient SITUATION 2: Clinical diagnosis as in situation 1 INVESTIGATION: All investigations as in situation 1 Additional investigations: MRI, MR Fistulogram in complex, high, trans sphincteric, supra and extrasphincteric fistulae Colonoscopy – associated ulcerative colitis, carcinoma, TB etc HIV test in suspected cases Biopsy when multiple openings are present, malignancy or specific cause is suspected prothrombin time HbA1C in cases of diabetes mellitus TREATMENT: as in situation 1 Colostomy – when significant sphincter involvement is present, or non healing ulcer Multiple procedures – complex fistula with multiple tracts SOP: Day Care – Low fistulae – subcutaneous / submucous fistula All others – should be admitted 37 WHO DOES WHAT? Doctor: Clinical examination Diagnosis Planning surgery Post op care Anesthesia Nurse: Siting of colostomy when required, by stoma nurse Care of stoma Dressing of the wound Pre & post operative care Assisting during surgery Technician: Pre op equipment and drugs to be checked and kept ready Assist anesthetist in the OT Assist the surgeon, positioning of the patient REFERENCES Owen G, Keshava A, Stewart P, Patterson J, Chapuis P, Bokey E, Rickard M. Plugs unplugged. Anal fistula plug: the Concorf experience. ANZ J Surg. 2010 May, 80 (5):341-3 Department of Colorectal Surgery, Concord Repatriation General Hospital, Hospital Road, Concord, NSW 2139, Australia. Owen_g@optusnet.com. K.Rajgopal Shenoy, Manipal Manual of Surgery second edition; reprint 2009. CBS Publishers and Distributors (Pvt.) Ltd., India 38 Shackelford’s Surgery of the Alimentary Tract 6th Edition by Charles J. Yeo MD Saunders 2006 ISBN: 1416023577 RESOURCES REQUIRED FOR ONE PATIENT / PROCEDURE (Patient weight 60kgs) Situation Human Resources Investigations Drugs/Consumables Equipment 1 Surgeon – 1 Medical Officer / Assistant Surgeon – 1 Staff Nurse – 1 Technician – 1 Nursing Orderly – 1 Sweeper - 1 Haemogram Urine Analysis Blood Sugar Antibiotics Analgesics I V Fluids Sutures Anesthetic drugs Lignocaine dressings OT Table and lights Autoclave General surgery set Cautery Suction Pulse Oximeter Anesthetic equipment 2 Consultant – 1 Resident – 1 Staff nurse – 1 Technician – 1 Nursing Orderly – 1 Sweeper - 1 Same as above + hbA1C coagulation profile ECG X-Ray chest Same as above + stoma bag Same as above