Entero-cutaneous Fistulas

By : Dr. Anurag

INTRODUCTIONINTRODUCTION

Fistula is defined as an abnormal communication between two epithelialized surfaces.

Enterocutaneous fistula is an abnormal communication between the skin with various parts of the gut, such as duodenum, jejunum etc.

The word fistula means a “pipe” or “flute” in Latin.

The ileum is the most common site of origin of Enterocutaneous fistula.

CLASSIFICATION

ETIOLOGYETIOLOGY

Webster and Carey proposed five mechanisms of fistula formation :

1> Congenital : - Rare

- Failure of obliterate of Vitello-intestinal duct.

- Post natal slough of the stump.

2> Trauma : - Major penetrating trauma.

- Damage control laparotomy techniques

3> Infection : - intra abdominal Abscess and invasive intestinal infections like amoebiasis, coccidiomycosis, tuberculosis etc.

- Intestinal perforation in ileum from tuberculosis or enteric fever - Actinomyces infection post appendectomy.

4> Iatrogenic :

- Intra-abdominal abscess - 75-85% are iatrogenic - after surgery for bowel obstruction, cancer, or IBD

5> Inflammation, Irradiation or Tumour :

- Crohn’s disease may cause ECF – post op more common than spontaneous.

- ECF after anastomosis/appendicectomy/simple exploration in Crohn’s disease. - Irradiation for pelvic malignancies etc may lead to a chronic non-healing ECF.

PREVENTION OF FISTULAPREVENTION OF FISTULA

- Acute intra-operative perforations- early identification and closure.

- Serosal tears should be repaired immediately.

- Aggressive adhesiolysis should be avoided to prevent serosal tears.

Post operatively anastomotic leakFeverAbdominal painContinuous drain containing intestinal contentGeneral condition not improving

DIAGNOSIS OF PERFORATION AND FISTULADIAGNOSIS OF PERFORATION AND FISTULA

STAGING AND CLASSIFICATIONSTAGING AND CLASSIFICATION

• Stabilization

• Sepsis control

• Skin care

• Nutrition

• Anatomy identification

• Plan to deal with the fistula

MANAGEMENTMANAGEMENT

S-S-N-A-PS-S-N-A-P

STABILIZATIONSTABILIZATION

In 24 to 48 hours.

First step - resuscitation and stabilization of the patient.

Initial efforts – intravenous fluid resuscitationcontrol of infectionprotection of surrounding skinmeasuring and replacing ongoing losses.

> Intra-abdominal/subcutaneous abscesses should be drained

A. RESUSCITATIONA. RESUSCITATION

Restoration of normal circulating blood volume correction of electrolyte and acid-base imbalance Initial management- RL and NS Strict input and output measurements CVP monitoring urinary catheterization. Ongoing fluid losses should be fully replaced Associated with hypokalemia and metabolic acidosis- correction. Output of fistula should be monitored Urine output should be restored to greater than 0.5mL/kg/hr. If needed transfuse blood.

B. NUTRITIONB. NUTRITION

73% of enteric fistulae closes spontaneously in adequately nourished patients,

as against 19% in malnourished patients.> Nutritional support needs to begin as soon as the patient is stabilized.> Nutrition can be parenteral or enteral route, based on the anatomy of the fistula.> Its advisable to provide at least a part of the daily nutritional requirement through enteral route.(adequate is 25%).> Nutrition via the enteral route helps in maintaining the intestinal mucosal barrier, more efficacious delivery of nutrients, stimulating hepatic protein synthesis.> ORS should be given when oral intake is possible.> In proximal fistulae, the enteral feeding tube may be entered beyond the fistula to provide enteral nutrition.> It is advisable to enter feeding tube beyond ligament of Treitz for a gastric or duodenal fistula.TPN is also given in patients who do not tolerate enteral feeds or have long standing ileus or before fistulous tract is well established.

NUTRITION CONTD..NUTRITION CONTD..

vitamins, trace elements, zinc and up to 10 times the daily requirement of Vitamin C should be provided.

> Mortality rate of 42% with albumin <2.5 mg/dl v/s 0% if >3.5 mg/dl.

TYPE OF FISTULA CALORIE REQ PROTEIN REQ

Low Output 30-35 kcal/kg/day 1-2 gm/kg/day

High Output 45-50 kcal/kg/day 1.5-2.5 gm/kg/day

C. CONTROL OF SEPSIS AND FISTULA EFFLUENTC. CONTROL OF SEPSIS AND FISTULA EFFLUENT

D. PHARMACOLOGICAL SUPPORTD. PHARMACOLOGICAL SUPPORT

> Somatostatin analogue Octreotide-100 – 250 mcg TDS reduces fistula output by 40 – 60% by the end of 24 hrs.

> Should be discontinued if ineffective for 48 hrs (side effects- hyperglycemia, elevated cholesterol and reduced bowel motility).

> Octreotide and TPN seem to have a synergistic effect on reduction of effluent volume and improvement in fistula closure rates.

> Proton-pump inhibitors and H2 receptor antagonists also help reduce fistula output especially in proximal fistulas.

> Complications include URTI, headache, fatigue etc.

INVESTIGATIONSINVESTIGATIONS

To locate Fistula

X-ray- show any foreign body

Oral dye / Charcoal – shows presence or absence, but not its location, cause or anatomy.

USG - locating intra-abdominal abscesses, guided aspiration

Fistulography- length & width of the fistula, anatomical location, the presence of any distal obstructions

CT Scan- oral and IV- highly recommended for duodenal & pancreatic fistula.

Endoscopy -principal use is in internal fistulas.

DECISIONDECISIONFactor Favorable Unfavorable

Organ of origin Esophageal, Duodenal stump, Pancreatic, Biliary, Jejunal, Colonic

Gastric, Lateral duodenal, Ligament of Treitz, Ileal

Etiology Postop (anast leak), Appendicitis, Diverticulitis

Malignancy, IBD

Output Low (<200-500cc/day) High (>500cc/day)

Nutritional status Well nourished Malnourished

Sepsis Absent Present

State of bowel Intestinal continuity, absence of obstruction

Distal obstruction, Abscess, Discontinuity, Irradiation

Fistula characteristics

Tract >2 cm, Defect <1cm Tract <1cm, Defect >1cm

Miscellaneous Original operation at same institution

Referred from outside institution

90% of small intestinal fistula which closed spontaneously within a month. 10 % fistulas closes spontaneously after 2 months and none after 3 months

Factors possibly responsible for failure of spontaneous closure are: Foreign Body Radiation Inflammation/ infection Epithelialization [F-R-I-E-N-D-S] Neoplasm Distal intestinal obstruction Steroids.

DEFINITIVE THERAPY

DEFINITIVE THERAPYDEFINITIVE THERAPY

> 80-90% will close within 6 weeks with conservative management.

> Surgery between 10 days and 6 weeks post-op will encounter the worst adhesions.

> Preferably wait up to 6 weeks before open exploration and repair of defect, but in case of fecal fistula, due to intense inflammation, it is prudent to wait up to 10-12 weeks.

> The patient should by then, be nutritionally optimized, patient should not be septic and patient should be vitally stable.

> Definitive operative correction remains the final step in the treatment of non-healing small intestinal fistulas.

> In majority of the cases, preferred operation is resection of the involved segment with primary end-to-end anastomosis.

> However if primary anastomosis is not possible, then both the proximal and distal ends of intestine are exteriorized.

> In case the fistula is deemed inappropriate for resection, such as when it develops after a deep pelvic procedure, staged approach involving bypass should be considered.

Basic principles of surgical treatment

• resection of the intestinal segment, fistula tract, and the adjacent part of the involved structure

• absence of extensive infection or inflammation - primary anastomosis of the divided intestinal segments and reestablish GI continuity

• presence of extensive infection - the divided intestinal segments are exteriorized.

• staged procedure is performed after the infection and inflammation subsides to re-establish GI continuity and reconstruction of the affected structure after 10 weeks.

Entero-cutaneous fistula :-Resection of the involved segment with primary end-to-end anastomosisExteriorization of both ends in the presence of extensive intra-abdominal sepsisBypass procedure when dense adhesions are encountered within the pelvis.

Choice of procedure for specific fistula types

Enteroenteric fistula• In the absence of associated infection:- Primary anastomosis

of healthy bowel ends. • In the presence of associated infection:- Proximal diversion

procedure with drainage of the abscess cavity.• Resection of the involved intestine and fistula after 4-6 weeks.• Resection should be limited to the area of intestine involved in

fistula formation.• Extensive resection is not advantageous and only increases

the risks of subsequent short-bowel syndrome and malabsorption.

Entero-vesical fistula• Surgical resection of the diseased intestine and the involved

area of bladder wall.• A primary anastomosis of the bowel is performed,• The bladder wall is closed in layers. • In presence of inflammation- transection of the intestinal

segment proximal and distal to the fistula, leaving the fistula tract in place. Both ends of the intestine are exteriorized.

Nephroenteric fistula• surgical procedure of choice is either total or partial

nephrectomy, with en-bloc resection of the fistula tract and the involved intestinal segment. The ends of the intestines are anastomosed primarily.

Enterovaginal fistula• Surgery is reserved for patients who do not respond to

conservative treatment with antibiotics and drainage of associated abscesses.

• An en-bloc resection of the involved intestinal segment with fistula and affected vaginal wall is performed.

• The intestinal ends are anastomosed primarily and the vaginal defect may be closed primarily.

Aortoenteric fistula• Emergency surgical intervention• The aortic prosthetic graft is removed• The intestinal defect is debrided and closed primarily. The

presence of extensive inflammatory or devitalized tissue may necessitate intestinal resection and an end-to-end anastomosis.

ENTEROATMOSPHERIC FISTULAENTEROATMOSPHERIC FISTULA

> In 1995, Ho HS and Frey CF used primary closure of gastric fistula with delayed external drainage as treatment for gastric fistulas.

> If the gastric fistula defect is too large to allow primary closure,then a Roux-en-Y gastrojejunostomy may be done.

> Duodenal fistulas are usually treated with tube duodenostomy or Roux-en-Y duodenojejunostomy.

> A feeding jejunostomy distal to the enteroenterostomy should always be considered.

Roux-en-Y DuodenojejunostomyRoux-en-Y Duodenojejunostomy

CONCLUSIONCONCLUSION

> Enterocutaneous fistulas are abnormal communication between the gut and skin.

> Majority of the ECF are due to iatrogenic causes (70-85%). Others include trauma, congenital causes. Spontaneous ECF may arise due to Crohn’s disease.

> Malnutrition, Electrolyte imbalances, acid-base imbalances and sepsis are the major causes of mortality in ECF.

> After initial stabilization of the patient by resuscitation( fluid, electrolytes, blood transfusions etc), the patient is subjected to various investigations to determine the location& anatomy of fistula, presence of distal obstruction etc.

> Enteral nutrition is always preferable to parenteral nutrition provided the patient tolerates enteral feeds.

> Local wound care by application of ostomy bag and pastes are essential.

> Drainage of intra-abdominal abscesses, treatment of sepsis is of utmost importance.

> After proper optimization, patient undergoes definitive therapy which includes resection of the fistulous segment of the gut.

> ECF with large abdominal defects may require VAC devices/ biologic mesh SSG to help close the defect.

THANK YOUTHANK YOU