BY DR KACHE S ASURGERY DEPT ABUTH, SHIKA ZARIA

MODERATOR ; DR UKWENYA

DEFINITION

OVERVIEW OF INTESTINAL FISTULAE

CLASSIFICATION OF ENTEROCUTANEOUS FISTULA

AETIOLOGY

PATHOPHYSIOLOGY

MANAGEMENT PROTOCOL

PREVENTION

CONCLUSION

Enterocutaneous fistula is an abnormal communication between a intestine & the skin. It is also called external intestinal fistula

The communication(track) is usually formed by granulation tissue but in some cases may be lined by epithelium

• INTERNAL-communication between 2 or more hollow viscera, without external communication

• EXTERNAL(ENTEROCUTANEOUS)-when a hollow viscus discharges to body surface

• MIXED-when both components are present• SIMPLE-single direct track• COMPLICATED/-multiple tracks or an assoc

abscess cavity• LATERAL-arising from side of a hollow viscus• END FISTULA-arising from whole circumference of

the involved bowel & there is no further continuity of the gut

VOLUME OF OUTPUT-

High output- >500ml/24hrs Moderate Output- 200-500ml/24hrs

Low output- <200ml/24hrs, with exception of pancreatic & hepatobilliary fistulae

ANATOMIC SITE-Proximal & distal

XTIC OF TRACK- Simple or Complicated

CIRCUMFERENCE- End fistula or lateral fistula

Proposed by Siteges-Sera et al & modified by Schein et al as follows

TYPE MORTALITY RATE

I. Abdominal oesophagus + gastroduodenal fistulae 17%

II. Small bowel fistulae 33%

III.Large bowel fistulae 20%

IV.Fistula at any site with assoc large abd. Wall defect 60%

SURGERY-(commonest cause) .usually due to unrecognised injury to bowel as a result of careless dissection or due to breakdown of anastomosis

TRAUMA- Blunt or Penetrating

SPONTANEOUS EXTENSION of intraabdominal dx thru the abd wall e.g

I. Sloughing of a strangulated hernia

II. Pointing of an empyema of the gallbladder

III.Duodenal ulcers eroding thru abd. wall

INFLAMATORY CONDITIONS such as TB, Anastomotic ulcer & diverticular dx, chron’s dx

RADIATION ENTERITIS- presents several years after initial exposure

CONGENITAL- e.g patent vitello-intestinal duct(umbilical fistula)

• Loss of GI ContentHypovolaemia, Acid-base and electro-lyte abnormalities, Malnutrition.

• SepsisIntra-abdominal sepsisWound infection

• Skin problems.

• Anaemia

Portion of gut below the fistula is by-passed resulting in malabsorption of essential nutrients

Fistula + complications + catabolic effects of sepsis = increased energy expenditure

Body stores of glycogen & fat are progressively depleted & proteins mainly from muscles

Vit & trace element def. also occur

Resistance to infection & impaired wound healing

If fistula track is not effectively walled off from surrounding structures , there is escape of enteric content into normally sterile areas such as peritoneal or pleural cavities

Fistula is unlikely to close in presence of sepsis

Assoc. toxaemia & circulatory disturbances may result in multiple organ failure

High fluid loss:

◦ Large fistula

◦ High fistula

◦ Distal obstruction

Advances in electrolyte replacement & nutritional support measures have allowed surgeons to maintain pts in a good condition until the fistula closes spontaneously or the pt becomes fit for a definitive surgical correction

Attempts at early surgical closure, in an effort to avoid the problems of fluid & electrolyte imbalance, malnutrition & sepsis, were assoc. with very high mortality rates(Monod Broca 1977)

Sheldon et al(1971) suggested a four phase approach that could successfully put mgt priorities in order

PHASE

I. Resuscitation & stoma care

II. Institution of nutritional treatment

III.Investigations & continuing nutritional Rx

IV.Definitive treatment plan

RESUSCITATION- follow ABC-correct hypovolaemia, restore fluid & electrolyte

balance using plasma substitute, blood transfusion

-maintain on daily req. + est. loss via fistula

PROTECTION OF SKIN & COLLECTION OF FISTULA EFFLUENT- main aim of stoma mgt is the application of effective skin protectives & a disposable drainage bag which will collect effluent & allow accurate measurement

Irving & Beadle(1982) classified skin problems assoc. with ECF into four categories

I. A single orifice passing thru an intact abd. Wall or otherwise healed scar around which the skin is flat & in reasonably good condition

II.Single or multiple orifices passing thru the abd wall close to bony prominences, surg. Scars, other stomas, the umbilicus

III.Fistula thru small dehiscence of main wound

4. Fistula thru a large dehiscence or at bottom of gaping wounds

Stoma mgt cat. 1-silicon barrier preparation -apply adhesive drainable bags

Extra skin protection(adhesive wafers)-in high output fistula

Stoma mgt cat 2-severely excoriated skin, impossible for any appliance to adhere

-Nurse pt face down on a split bed or Stryker frame for up to 48hrs

Stoma mgt cat 2 cont- use large sheets of adhesive wafer(20x20)

-cut to fit various holes in the abd

-protective paste can be used to seal edges

-Apply large bag(sometimes 2 or 3 small bags)

-if abd scarred by previous surg, resulting grooves & gullies shd be filled

Stoma mgt cat 3- use adhesive wafers-large sized bags

Stoma mgt cat 4

-Initially low pressure sump suction drainage to remove effluent

-This is continued until the wound shrinks to a size that can be managed by the techniques described above

Aim is to provide adequate & sustained nutritional Rx in order to maintain the pt, until the fistula closes spontaneously or until the pt is fit for surgery.

High output or proximal fistula- commence parenteral nutrition within 48hrs.once phase I procedures have been completed

If subsequent invx reveal >100cm of functioning small bowel, proximal or distal to the fistula, it may be possible to phase in enteral regimens

In pts with low output or distal fistula, enteral feeding can be commenced from the beginning

Parenteral nutrition-via central feeding lines

Enteral nutrition-orally

-NG tube

-Gastrostomy, Jejunostomy

Nitrogen requirement= Daily urinary nitrogen excretion + 3-4g

Septic pts=25-30g(10-15g) Energy Req = 4000-5000kcal/day(rarely exceeds

2000-3000kcal/day)

ENTERAL PREPS- Elemental diet of AA, Oligopeptides, Triglycerides, Simple sugars preferably in liquid form

Said to be totally absorbed from 150-250cm of small bowel

E.g conplan, casilla, astymin

• Once nutritional Rx has been established the pt is investigated fully to answer the following questions

1.What is the origin of the fistula & the anatomy of its track

2.What is the condition of the bowel at the site of the fistula? discontinuity or active disease

3. Is there obstruction distal to the fistula?

4.How much normal bowel is available?

5. Is there an assoc. abscess cavity?

CLINICAL EVALUATION Hx of surgery Hx of discharging wound from surgical scar or

any other part of the body Hx of underlying dx Hx of fever, abd. Pain Hx of bowel habit; is pt passing stool or not

O/E Fever, tarchycardia, abd. Tenderness, guarding,

rigidity Signs of Dehydration & Malnutrition Discharging wound

FISTULOGRAPHY- valuable for narrow well defined fistula opening, doubtful value for high output fistula in depths of gaping wounds

-outline track & abscess cavity

BARIUM CONTRAST STUDIES-outline track, abscess cavity, demonstrate length of remaining bowel

ULRASOUND SCANNING- abscess cavity

CT SCAN- abscess cavity, Percut. Drainage ENDOSCOPY- useful in revealing underlying dx ROUTINE INVX- Fbc, U&E

If pt is improving & flow charts indicate a falling fistula effluent & a rising plasma albumin & body wt- it is worth persisting with non-surgical Rx without time limit(Alexander Williams & Irving 1982)

However, if peritonitis or abscess cavity is present- urgent operative Rx shd be instituted

In the absence of spontaneous closure within 4-

6wks of nutritional support- surgical closure shd be undertaken

FACTORS RESULTING IN FAILURE OF SPONTANEOUS CLOSURE

Complicated fistula with abscess cavity

Distal obstruction

Total discontinuity of bowel ends

Mucocut. Continuity(short track <2cm) or epithelialized track

Radiation enteritis

Presence of active dx at site of fistula

TREATMENT OF COMPLICATIONS

Infection- antibiotics indicated in resp, uti, septicaemia, spreading cellulitis, I & D for abscess

Haemorrhage-bleeding may arise from

I. Erosion of a bld vessel by an abscess cavity

II.Stress ulceration due to assoc severe sepsis

III.From underlying dx e.g pud, neoplasmRX-H2 antagonist

-pack abscess cavity following drainage

-selective embolization

Venous thromboembolism

-Anticoagulants

PHARMACOLOGIC TREATMENT H2 Antagonist – gastroduodonal fistulae

Somatostatin Analogues (Octreotide) – small bowel fistulae

Those designed to improve pts condition I&D for abscesses Insertion of central lines Creation of feeding enterostomies

Those designed to close the fistula Usually a staged procedure Incision shd be extensive, commencing from

virgin area of abdomen In septic pts- initial resection, anastomosis at a

later date

In non septic pts- resection + prim end to end anastomosis done

Identification of high risk individuals.

Meticulous surgical technique.

Proper use of peri-operative antibiotics.

Thorough preoperative bowel preparation.

Most uncomplicated ECF will close spontaneously when properly managed

Surgery is usually not an immediate priority except to deal with complications

When surgery is required, fistula resection & anastomosis or by-pass procedures are the preferred surgical procedures