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
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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
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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