This document discusses intestinal fistulas, including: - Definitions, classifications, and etiologies of intestinal fistulas. Fistulas can be internal or external, simple or complicated, and caused by conditions like Crohn's disease or trauma. - A four phase approach to management: initial stabilization, continued support for 2 days, enteral feeding trial from 2-5 days, and definitive surgery after 5 days if needed. - Nutritional management involves IV or enteral feeding to correct deficiencies from fistula output. Output and electrolytes must be closely monitored. - Investigations help determine fistula anatomy and underlying causes. Surgical intervention aims to aid closure, correct malnutrition, or re

1. Intestinal Fistulas
Dr. Ketan Vagholkar
MS, DNB,MRCS, FACS
Consultant General Surgeon
&
Professor of Surgery

2. Intestinal Fistulas
by
Dr. Ketan Vagholkar
MS, DNB, MRCS, FACS
Consultant General Surgeon
&
Professor of Surgery
Introduction:
In a professional lifetime the majority of surgeons will
encounter few patients with an intestinal fistula. More
external fistulas follow surgical operations, accidental
trauma or irradiation and are only occasionally
spontaneous. The majority of internal fistulas are associated
with Crohn’s disease, malignancy and diverticulitis
although interesting rarities will be encountered
occasionally. Many external fistulas are trivial in their
effects and short in duration and some internal fistulas give
no symptoms. However both internal and external fistulas
can pose an enormous challenge, complicated by associated
sepsis and gross anatomical abnormalities. There are many
who regard the management of high output
enterocutaneous fistulas as the ultimate surgical challenge.
Advances in parentral nutrition, in diagnostic techniques
and in stoma care have added new dimensions to the
treatment of intestinal fistulas.
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3. Definition:
The word fistula is derived from the identical Latin word
for a pipe, but its incorporation into English medical
literature was not probably from its Latin origin, but from
the old French word ‘Festre’ which led to the old English
words ‘ fistle and fistule’ . From the medical point of view
a fistula is an abnormal communication between two
epithelial surfaces.
Classification:
There are various ways by which fistulae can be classified.
These classification systems may at times aid in planning
management strategies for the same.
• External/ enterocutaneous fistulas.
• Internal
• Occasionally both internal & external.
• Simple- one single track.
• Complicated- multiple tracks or associated abscess
According to the site of the hole
• Lateral- leakage from the side of the hollow viscus.
• End- Leakage from the whole diameter of section of
the bowel involved.
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4. Based on the output.
• High output >/= 500cc
• Low output < 500cc
Practical Considerations for defining a fistula
1. In case of external fistulas the leakage to the
surface should in most circumstances have
persisted for more than 24 hours.
2. Leakage and the communication must be
relatively sealed off from the surrounding tissues
and cavities.
Etiology:
Congenital - T-O fistulas, persistent vitello intestinal duct.
Traumatic fistulas – Penetrating & blunt abdominal trauma
Inflammatory – Anastomotic leaks, Cohn’s disease, T.B,
Actinomycosis, impacted gall stone in the
Hartmann’s pouch.
Neoplastic – Colonic & pancreatic carcinomas.
Degenerative diseases – aortoduodenal fistulas.
Post irradiation fistulas
Post operative fistulas –
• tension on the suture line
• ischaemia
• associated sepsis
• distal obstruction
• malignant involvement
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5. Four Phase Approach [Sheldon et al]
Initial Phase (on presentation)
1. Restore blood volume.
2. Begin correction of fluid and electrolyte imbalance.
3. Control fistula, protect skin, collect and measure
effluent.
4. Drain abscesses and consider antibiotic therapy.
Second Phase (Up to 2 days)
1. Continue fluid and electrolyte therapy
2. Begin IV feeding.
Third Phase (Up to 5 days)
1. Institute enteral feeding if possible either orally or by
tube feeding or by jejunostomy below a high fistula.
2. Demonstrate the anatomy of the fistulas by contrast
studies and fistulography.
Fourth Phase (After 5 days)
1. Continue nutritional treatment until the fistula closes
or if it fails to close, until the patient is able to
withstand definitive surgery.
2. Operate to eliminate sepsis if recurring.
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6. Intravenous Treatment Regimens:
A] Resuscitation
B] Fluid & electrolyte regimens.
C] Nutritional regimens (enteral/parentral)
Common water and electrolyte problems in fistula patients:
Dehydration, hyponatremia, hypokalemia, metabolic
acidosis, metabolic alkalosis, hypernatremia &
hyperosmolar syndrome in patients fed IV or orally with
elemental diets.
Water requirements = Normal requirements + add.
Requirements resulting from the fistula- modifications
imposed by complications such as renal failure.
Daily requirements= basal requirements+additional
requirements
5% dextrose 2000cc 1250cc 3250cc
Normal saline 500cc 750cc 1250cc
KCl 80mmol 40mmol 120mmol
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7. Measurements necessary for assessment and control of
water and electrolyte balance in patients with intestinal
fistulas.
Measurements Frequency
Clinical Pulse,BP,CVP,RR As
clinically
indicated
Blood Hct, ABG As
clinically
indicated
Serum Na,K,Cl,Urea,Glucose,Creatinine,osmolarity Daily
Urine Vol/24hrs, Na, K, Cl, Urea, Creatinine. Daily to
be done
but every
third day
if stable
Fistula Vol/24hrs, Na, K, Cl, Urea, bicarbonates. Daily to
output be done
but every
third day
if stable
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8. Nutrition:
Nutritional requirements
Glucose & amino acids proportionate to the nitrogen
requirements and excretion
Essential fatty acids, fat soluble vitamins, water soluble
vitamins, trace elements, hematinics
Enteral
Low residue enteral feeding programs
1. Amino acid, simple glucose containing sugars and
triglycerides
2. Oligopeptides, triglycerides and simple sugars.
3. Liquid whole proteins, triglycerides and complex
sugars.
4. Elemental diets which contain simplest components of
the main categories of nutrients.
Advantages: totally absorbed, no digestive enzymes
required.
Complications: gastric stasis, diarrhea, hyperosmolar
dehydration, anemia. (Folate and B12 deficiency)
Parentral
Venous access for short term TPN
1. Median basilica vein at the elbow.
2. Subclavian vein cannulation via infraclavicular
approach.
3. Internal jugular vein cannulation.
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9. Complications: Pneumothorax, catheter blockage,
infection, catheter fracture, extravasation.
Monitoring Nutritional Status
Hb Daily
Body weight Daily
Nitrogen balance Daily
S. albumin Twice
weekly
Anthropometry(midarm circumference in Weekly
cms)
S. folate, Fe, Mg & Zn. Weekly
S. Cu, Mn, B12 Monthly
Investigations:
Demonstration of the anatomy of the fistula and diagnosis
of the underlying disease.
• Clinical assessment
• Markers e.g. methylene blue
• Radiological studies
1. origin of the fistula
2. complexity and size of the fistula tract
3. condition of the bowel from where the fistula arises
4. whether there is continuity of the bowel at the site of
anastomosis or total disruption
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10. 5. whether there is distal obstruction
E.g. plain x rays, contrast studies, fistulography, biopsy,
imaging CT, other tests like S. gastrin for ZE syndrome.
Detection of sepsis:
Clinical and bacteriological tests
• pus swabs
• sputum & blood culture
• pus samples
Detection of abscess cavities
• USG
• CT
• Neutrophil isotope scans (indium leukocyte scans)
Other methods: increased B 12 levels in liver abscess
Complications in fistula patients
1. Infection
2. Abscesses
3. Septic shock
4. Pulmonary problems
5. Venous thrombosis and embolism
6. GI bleeding and bleeding from the fistula track.
7. Psychological problems (depression)
8. Demoralization of relatives and staff.
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11. Local management of fistulas
Appliances
Suction devices
Irrigation with NaCl+lactic acid (in pancreatic and
duodenal fistulas to prevent autodigestion)
Local applications and skin grafting (silastic casts)
Drugs to reduce secretions: Proton pump inhibitors in
gastric fistulas, Probanthine and glucagons in pancreatic
fistulas.
Diversion.
Nursing care
General care: Mouth care, skin care, prevention of pressure
sores, physiotherapy, prevention of venous thrombosis,
psychological support.
Specific care: Care of fistula site, care of skin around the
enterostoma and tube drains, maintenance of nutrition.
Assessment of prognosis and continuing treatment:
Prognostic factors
High fistulas
Abdominal dehiscence>10cms
Fístula o/p > 1500cc /24hrs
Multiple fístulas
Intraperitoneal abscesses
Small bowel resection >150 cms
Septicemia
Intestinal obstruction
Respiratory infection
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12. Intra/extra luminal GI bleeding
Renal/hepatic insufficiency
Reasons for failure to close spontaneously
1. Total discontinuity of the bowel ends
2. Distal obstruction
3. Chronic abscesses
4. Mucocutaneous continuity
5. Damage or diseased intestine
6. Malnutrition
Criteria for operative intervention.
Internal fistula
1. Serious diarrhea with fluid and electrolyte imbalance.
2. Hemorrhage
External fistulas
1. Fistulas that have failed to close on conservative
treatment.
2. Investigation has revealed a reason why it will not
close.
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13. Principles of surgical intervention in intestinal fistulas.
Category I
Operations designed to
1. aid spontaneous closure
2. correct malnutrition
3. Control output from drains, abscess &fistulas by
establishing proximal diversions and feeding stomas
distally.
Category II
Operations aimed at removal of
1. Diseased bowel
2. Associated fistula (not always to carry out a
restoration anastomosis)
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14. General principles governing definitive surgery for
intestinal fistulas.
1. Allow plenty of time for operation
2. Aim for adequate exposure
3. Only undertake resection of the fistula and
reanastomosis in patients in whom malnutrition has
been corrected and sepsis controlled.
4. Adhesions should be divided by sharp dissection.
5. Following resection anastomosis raw areas be covered
with omental pedicle raised on the right or left
gastroepiploic artery.
6. Bypass operation for fixed inoperable lesions.
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