Intestinal fistulas


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Intestinal fistulas pose the greatest challenge to the General Surgeon. The presentation provides abrief guideline for management of this complex problem.

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Intestinal fistulas

  1. 1. Intestinal Fistulas Dr. Ketan Vagholkar MS, DNB,MRCS, FACS Consultant General Surgeon & Professor of Surgery
  2. 2. Intestinal Fistulas by Dr. Ketan Vagholkar MS, DNB, MRCS, FACS Consultant General Surgeon & Professor of SurgeryIntroduction:In a professional lifetime the majority of surgeons willencounter few patients with an intestinal fistula. Moreexternal fistulas follow surgical operations, accidentaltrauma or irradiation and are only occasionallyspontaneous. The majority of internal fistulas are associatedwith Crohn’s disease, malignancy and diverticulitisalthough interesting rarities will be encounteredoccasionally. Many external fistulas are trivial in theireffects and short in duration and some internal fistulas giveno symptoms. However both internal and external fistulascan pose an enormous challenge, complicated by associatedsepsis and gross anatomical abnormalities. There are manywho regard the management of high outputenterocutaneous fistulas as the ultimate surgical challenge.Advances in parentral nutrition, in diagnostic techniquesand in stoma care have added new dimensions to thetreatment of intestinal fistulas. 1
  3. 3. Definition:The word fistula is derived from the identical Latin wordfor a pipe, but its incorporation into English medicalliterature was not probably from its Latin origin, but fromthe old French word ‘Festre’ which led to the old Englishwords ‘ fistle and fistule’ . From the medical point of viewa fistula is an abnormal communication between twoepithelial surfaces.Classification:There are various ways by which fistulae can be classified.These classification systems may at times aid in planningmanagement strategies for the same.• External/ enterocutaneous fistulas.• Internal• Occasionally both internal & external.• Simple- one single track.• Complicated- multiple tracks or associated abscessAccording 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. 2
  4. 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 traumaInflammatory – 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 fistulasPost operative fistulas – • tension on the suture line • ischaemia • associated sepsis • distal obstruction • malignant involvement 3
  5. 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. 4
  6. 6. Intravenous Treatment Regimens:A] ResuscitationB] Fluid & electrolyte regimens.C] Nutritional regimens (enteral/parentral)Common water and electrolyte problems in fistula patients:Dehydration, hyponatremia, hypokalemia, metabolicacidosis, metabolic alkalosis, hypernatremia &hyperosmolar syndrome in patients fed IV or orally withelemental diets.Water requirements = Normal requirements + add.Requirements resulting from the fistula- modificationsimposed by complications such as renal failure.Daily requirements= basal requirements+additionalrequirements5% dextrose 2000cc 1250cc 3250ccNormal saline 500cc 750cc 1250ccKCl 80mmol 40mmol 120mmol 5
  7. 7. Measurements necessary for assessment and control ofwater and electrolyte balance in patients with intestinalfistulas. Measurements FrequencyClinical Pulse,BP,CVP,RR As clinically indicatedBlood Hct, ABG As clinically indicatedSerum Na,K,Cl,Urea,Glucose,Creatinine,osmolarity DailyUrine Vol/24hrs, Na, K, Cl, Urea, Creatinine. Daily to be done but every third day if stableFistula Vol/24hrs, Na, K, Cl, Urea, bicarbonates. Daily tooutput be done but every third day if stable 6
  8. 8. Nutrition:Nutritional requirementsGlucose & amino acids proportionate to the nitrogenrequirements and excretionEssential fatty acids, fat soluble vitamins, water solublevitamins, trace elements, hematinicsEnteralLow 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 enzymesrequired.Complications: gastric stasis, diarrhea, hyperosmolardehydration, anemia. (Folate and B12 deficiency)ParentralVenous access for short term TPN 1. Median basilica vein at the elbow. 2. Subclavian vein cannulation via infraclavicular approach. 3. Internal jugular vein cannulation. 7
  9. 9. Complications: Pneumothorax, catheter blockage,infection, catheter fracture, extravasation.Monitoring Nutritional StatusHb DailyBody weight DailyNitrogen balance DailyS. albumin Twice weeklyAnthropometry(midarm circumference in Weeklycms)S. folate, Fe, Mg & Zn. WeeklyS. Cu, Mn, B12 MonthlyInvestigations:Demonstration of the anatomy of the fistula and diagnosisof 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 8
  10. 10. 5. whether there is distal obstructionE.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 samplesDetection of abscess cavities • USG • CT • Neutrophil isotope scans (indium leukocyte scans)Other methods: increased B 12 levels in liver abscessComplications 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. 9
  11. 11. Local management of fistulasAppliancesSuction devicesIrrigation with NaCl+lactic acid (in pancreatic andduodenal fistulas to prevent autodigestion)Local applications and skin grafting (silastic casts)Drugs to reduce secretions: Proton pump inhibitors ingastric fistulas, Probanthine and glucagons in pancreaticfistulas.Diversion.Nursing careGeneral care: Mouth care, skin care, prevention of pressuresores, physiotherapy, prevention of venous thrombosis,psychological support.Specific care: Care of fistula site, care of skin around theenterostoma and tube drains, maintenance of nutrition.Assessment of prognosis and continuing treatment:Prognostic factorsHigh fistulasAbdominal dehiscence>10cmsFístula o/p > 1500cc /24hrsMultiple fístulasIntraperitoneal abscessesSmall bowel resection >150 cmsSepticemiaIntestinal obstructionRespiratory infection 10
  12. 12. Intra/extra luminal GI bleedingRenal/hepatic insufficiencyReasons 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. MalnutritionCriteria for operative intervention.Internal fistula 1. Serious diarrhea with fluid and electrolyte imbalance. 2. HemorrhageExternal fistulas 1. Fistulas that have failed to close on conservative treatment. 2. Investigation has revealed a reason why it will not close. 11
  13. 13. Principles of surgical intervention in intestinal fistulas.Category IOperations 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 IIOperations aimed at removal of 1. Diseased bowel 2. Associated fistula (not always to carry out a restoration anastomosis) 12
  14. 14. General principles governing definitive surgery forintestinal 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. 13