Colon and Small Bowel—Enterocutaneous Fistula
Pathophysiology
Remember FRIEND mnemonic . . . foreign body, radia- tion injury, ischemia/IBD, epithelialized tract, neoplasm, and distal obstruction as causes for fistula. Important con- cepts surrounding enterocutaneous fistulae are controlling infection and drainage, maximizing nutrition/electrolytes, and ruling out distal obstruction/associated abscess.
Way Question May be Asked?
“43 y/o female status post an exploratory laparotomy with extensive enterolysis and adhesiolysis and repair of multi- ple enterotomies for persistent PSBO develops a fever to 100.8 and on exam has erythema and tenderness about the lower portion of her incision.” The question typically is open ended with first a discussion about how to manage a post-op fever and then hones in on small bowel contents coming out of the incision the next day (change scenario).
How to Answer?
First, the basic approach to postoperative fever which must be systematic (remember 5Ws):
Atelectasis UTI IV sites DVT/PE
Wound infection Anastomotic leak Drug Fever
Rare entities (parotitis, in sinusitis, decubitus ulcer;
acalculous cholecystitis, C. diff, transfusion reaction, thyroid storm, Addisonian crisis)
Symptoms of cough, abdominal pain, shortness of breath, pain at IV sites
Physical Exam
Close examination of wound for erythema, fluid, SQ air, tenderness, culture any drainage, take out staples early
Diagnostic Tests
Labs, CXR, AXR, U/A C+S, BCx, (one from any inva- sive catheters) U/S-abdominal/ extremity, CT scan Start antibiotics if evidence of sepsis
Once you have proved to them you understand how to work-up post-op fever, then the question will likely focus on management of the enterocutaneous fistula:
Drain fistula with sump drain: vacsponge and pro- tect surrounding skin
Measure output of fistula (gives you information about likelihood of closure)
Place CVP and restore lytes and intravascular volume NPO, TPN
H2 blockers
Somatostatin (+/− any real benefit) Abx if associated cellulitis/sepsis
CT scan to r/o abscess and/or place percutaneous drain
Fistulogram after 7–10 days to r/o distal obstruction Based on fistulogram, one of two possibilities:
(1) No distal obstruction or intestinal discontinua- tion—most low output enterocutaneous fistulae will close within 6 weeks
(2) Distal obstruction or failure to close or high out- put fistula need operative repair involving taking down the fistula, bowel resection, and reanasto- mosis +/− G- or J-tube if suspected prolonged post-op ileus
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Common Curveballs
Pt has SQ emphysema on examination of the wound and whole focus now shifts to managing a necrotizing soft-tissue infection
Pt has associated intraabdominal abscess that can’t be percutaneously drained
Complication after placing CVP line (make sure you check CXR)
CT scan will show multiple fluid collections but no dis- crete abscess (always describe how you would order CT scan – “with IV/PO contrast”)
Trying to push you into earlier operation Skin breakdown at fistula site
Same pt, but now with a history of Crohn’s disease Another fistula after you reoperate and take down the
first enterocutaneous fistula
Discussion about TPN (1 gm/kg/day protein, 25 kcal/kg/day CHO)
(25% glucose, 3–4% amino acids, 10% FFA want 50% of non-protein calories as glucose and 50% as FFA)
Strikeouts
Failure to do standard fever work-up
Operating too early for low-output fistula (give TPN chance to allow fistula to close)
Failure to consider all possible causes (like distal obstruction) prior to re-operation
Starting long discussion about use of fibrin glue to close fistula tract
Failing to be methodical in care of fistula: resuscitation, controlling fistula, expectant management and sup- plemental nutrition/TPN
Not being able to discuss basic TPN
18 Colon and Small Bowel—Enterocutaneous Fistula
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