Enterocutaneous Fistulas Flashcards
What are enterocutaneous (EC) fistulas?
Abnormal connections between the lumen of the gastrointestinal tract and the skin.
What is an enteroatmospheric (EA) fistula?
A direct communication between the bowel and a nonepithelialized granulating wound, often occurring after temporary abdominal closures.
How common are enteroatmospheric fistulas after temporary abdominal closures?
They occur in nearly 10% of cases.
What percentage of EC fistulas are iatrogenic or postoperative in etiology?
75%–85%
What are the primary causes of iatrogenic EC fistulas?
Anastomotic leaks (50%)
missed enterotomies (45%)
missed traumatic injuries
bowel puncture by percutaneous catheters
and erosion of foreign material (e.g., mesh) into adjacent bowel
What conditions are commonly associated with the spontaneous development of EC fistulas?
Inflammatory bowel disease
malignancy
prior radiation
What are some significant impacts on quality of life for patients with EC fistulas?
Malnutrition and chronic wounds that can be difficult to manage.
What is the overall mortality rate for patients with EC fistulas?
15% to 25%.
What are the primary causes of mortality in patients with EC fistulas?
Sepsis, malnutrition, and electrolyte imbalances.
What is the classic presentation of an EC fistula?
A patient several days to weeks after surgery developing fever, leukocytosis, and erythema around their incision, followed by purulent drainage that becomes bilious green or brown.
What signs might indicate an EC fistula in postoperative patients with abdominal pain, fever, and leukocytosis?
Intraabdominal fluid collections on CT scans.
What might happen after an image-guided percutaneous drain is placed in a patient with an EC fistula?
The drain initially produces purulent output, which then turns bilious or feculent
How do the symptoms of patients with EC fistulas vary?
They range from severe sepsis with localized or diffuse peritonitis to mild abdominal discomfort and leukocytosis
What is an important initial sign of an EC fistula in the context of wound infection?
The drainage of purulent fluid from the incision site that later becomes bilious or feculent in color.
What are the classifications of EC fistulas based on daily output?
Low-output: < 200 mL per day
Moderate-output: 200 to 500 mL per day
High-output: > 500 mL per day
Why should patients with EC fistulas be made nil per os (NPO) after recognition?
To establish baseline fistula output without oral or enteral stimulation
How does the classification of EC fistulas influence their management?
Low-output fistulas are more likely to close spontaneously
while high-output fistulas are associated with complications such as dehydration, electrolyte disturbances, and malnutrition.
What types of EC fistulas are classified based on the origin of the gastrointestinal leak?
Gastric
duodenal
enteric (small intestine)
and colonic (colocutaneous) fistulas
What is the first step in the management of EC fistulas?
Stabilization and sepsis control
How should septic patients with EC fistulas be managed initially?
According to the Surviving Sepsis Guidelines
including fluid resuscitation, hemodynamic assessment, potential transfer to ICU, and broad-spectrum antibiotics
What percentage of mortality associated with EC fistulas is due to sepsis and uncontrolled infection?
More than 70%
What is the next step after stabilizing a patient with an EC fistula?
Obtain source control by draining any intraabdominal abscesses.
What type of imaging should be obtained to identify and characterize abscesses in EC fistula patients?
Abdominal axial imaging.
How can superficial abscesses be managed in EC fistula patients?
Through a small incision and debridement bedside procedure to ensure continued drainage.
How should deeper intraabdominal or pelvic abscesses be managed?
With image-guided percutaneous catheter placement by interventional radiology.
What is the goal of managing an uncontrolled enteric leak in EC fistulas?
To convert it into a controlled EC fistula.
When is operative intervention indicated in the initial management of EC fistulas
Rarely, except in cases of peritonitis or free perforation.
What should be avoided during the initial operation for EC fistulas due to the high risk of injury?
Extensive lysis of adhesions, as it can lead to injury of healthy bowel loops
What surgical actions are recommended if the source of the leak is identified during emergency surgery?
Bowel resection without creating an anastomosis, as primary repairs are often not durable.
What operations should be considered for damage control in EC fistula patients?
Fecal diversions and leaving drains to create a controlled fistula
When can antibiotics typically be stopped in EC fistula patients after initial source control?
After 4 to 7 days, pending clinical improvement
What should clinicians do if a patient with an EC fistula develops recurrent fevers, leukocytosis, or abdominal pain?
Have a low threshold to reimage, as new abscesses could develop even after initial source control
When does long-term management of EC fistulas begin?
As soon as the patient is stabilized and sepsis is controlled, usually within 2 days of diagnosis
How long can the long-term management of EC fistulas last?
Months to years.
What are the key components of long-term management for EC fistulas?
Fluid and electrolyte repletion
nutritional optimization
pharmacologic control of effluent volume
and wound care
What percentage of EC fistulas heal spontaneously with appropriate long-term management?
Approximately 30% to 35%.
How long does it typically take for EC fistulas to heal spontaneously with long-term management?
Within 5 to 6 weeks of diagnosis
What is the goal of long-term management in EC fistula patients?
To increase the likelihood of spontaneous closure and optimize the patient for potential operative intervention
Algorithm for the management of enterocutaneous fistulas.
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What complications can develop in patients with high-output EC fistulas?
Severe dehydration and electrolyte derangements.
What type of central access is often used for TPN in patients with high-output EC fistulas?
Long-term central access, such as peripherally inserted central catheters (PICCs)
What common electrolyte abnormalities occur in patients with high-output EC fistulas?
Hyponatremia, hypokalemia, and hypomagnesemia
What metabolic complication can develop in patients with duodenal fistulas?
Metabolic acidosis requiring sodium bicarbonate replacement.
What syndrome must be monitored for when starting or resuming nutrition in EC fistula patients?
Refeeding syndrome
Which laboratory value should be frequently checked to monitor for refeeding syndrome?
Serum phosphorus levels
How much protein can patients with EC fistulas lose daily, contributing to malnutrition?
Up to 500 g of protein
What markers should be closely monitored to assess nutritional status in patients with EC fistulas?
Prealbumin, albumin, and transferrin.
What is the nutritional requirement for patients with low-output EC fistulas?
20 kcal/kg per day of carbohydrates and fat, and 1 g/kg per day of protein
What are the nutritional requirements for patients with high-output EC fistulas?
30 kcal/kg per day of carbohydrates and fat, and 1.5 to 2.5 g/kg per day of protein.
Why is enteral feeding preferred over parenteral nutrition in EC fistula management?
Because it promotes mucosal integrity, maintains intestinal function, and supports immune function.
What is a potential drawback of oral intake for patients with EC fistulas?
It can substantially increase fistula output, complicating wound care
When is TPN typically used for patients with EC fistulas?
As a bridge to enteral feeding or for long-term nutrition if oral intake is not tolerated
What initial approach is often taken for patients with newly diagnosed EC fistulas?
A few days of bowel rest, with or without TPN, to observe if the fistula closes spontaneously or output decreases.
What should be done if fistula output persists after an initial period of bowel rest?
Gradually reintroduce an oral diet and monitor for increased output and malabsorption; consider TPN if needed
Can patients with high-output fistulas continue an oral diet?
Yes, as long as fistula output is controlled, wound care is manageable, and ostomy appliances are well-seated
What is fistuloclysis?
A method of enteral feeding distal to the EC fistula by cannulating the distal limb for tube feed instillation
How is the distal limb of the EC fistula identified for fistuloclysis?
Using a fistulogram performed by interventional radiology or in the operating room with fluoroscopy
What step can help secure the catheter and facilitate wound care during fistuloclysis?
Tunneling the catheter under the skin.
What is done with the high-volume liquid output from patients during fistuloclysis?
The effluent can be collected, strained, and refed into the distal feeding tube.
In what type of patients is fistuloclysis indicated?
In patients with EC fistulas not expected to close spontaneously, as cannulating the distal limb prevents closure
What are the benefits of fistuloclysis for patients who may require operative intervention?
maintains mucosal integrity and promotes intestinal adaptation and lengthening.
How does fistuloclysis affect the need for parenteral nutrition?
It enables patients to potentially wean off parenteral nutrition
What physiological effect does refeeding of succus have during fistuloclysis?
It activates the “ileal brake,” decreasing gastric acid secretion, pancreatic enzyme secretion, and peristalsis, which reduces EC fistula output.
What is a key component of long-term management for EC fistulas?
Controlling effluent volume
What are the first-line pharmacologic agents for controlling EC fistula output?
Opiate receptor agonists such as loperamide, diphenoxylate/atropine, codeine, and distilled tincture of opium.
How do opiate receptor agonists help manage EC fistula output?
They act on intestinal muscles to decrease peristalsis.
What role do proton pump inhibitors and H2 receptor antagonists play in EC fistula management?
They lower the acidity of fistula output and decrease volume through antisecretory effects.
What is the effect of amitriptyline in EC fistula management?
It causes constipation via anticholinergic pathways and helps slow output.
How does clonidine help manage EC fistula output?
As an alpha 2-adrenergic agonist, it increases mucosal absorption of fluids and electrolytes
What are examples of bulking agents used in EC fistula management?
Psyllium and banana flakes
When is cholestyramine particularly useful in managing EC fistulas?
In decreasing output from more proximal fistulas, such as those from the duodenum or proximal jejunum
What is the action of octreotide in high-output EC fistulas?
It reduces gastric acid and pancreatic enzyme secretions and enhances fluid and electrolyte absorption by prolonging transit time.
Does octreotide increase the likelihood of spontaneous fistula closure?
No, but it decreases output and the time to closure
What is the target output volume for managing high-output EC fistulas effectively?
Less than 1 to 1.5 liters per day.
What combination of products is often used to manage complex wounds surrounding EC fistulas?
Stoma paste, powders, barrier rings, hydrocolloid dressings, and specialty ostomy appliances.
Why are catheters that tunnel under the skin preferred for fistuloclysis
Because they come out away from the wound, allowing better placement of pouches and wound protection
What is the purpose of sump drains in the management of EA fistulas?
To collect effluent and divert it away from the surrounding skin.
How can vacuum dressings benefit wound care in EC fistula patients?
They promote granulation of surrounding tissues and protect them from effluent
What caution must be taken when using vacuum dressings on EC fistula patients?
They should not be placed directly on granulation tissue or skin grafts over the bowel to avoid creating new fistulas.
Why is it critical to characterize the anatomy of an EC fistula?
To determine the location of the fistula, assess the amount of bowel proximal and distal to it, and check for multiple fistulas
What imaging studies are used to characterize EC fistulas?
CT scans with oral contrast
upper GI swallow studies with small bowel follow-through,
contrast enemas
and fistulograms
What is the purpose of a fistulogram in EC fistula assessment?
To cannulate and inject contrast into the proximal and distal limbs of the fistula under fluoroscopy for detailed imaging
What can imaging studies reveal about the feasibility of fistuloclysis?
They can help determine if fistuloclysis is possible by assessing the anatomy of the fistula.
How can imaging studies help with operative planning for EC fistulas?
By assessing for distal obstructions that would make spontaneous closure unlikely and guiding surgical approaches
Why is it important to know if there are multiple fistulas present?
Multiple fistulas may complicate management and affect treatment strategies
What percentage of EC fistulas close within 2 months without operative intervention?
Approximately 30% to 35%
What characteristics of EC fistulas make them more likely to heal spontaneously?
Fistula tracts longer than 2 cm
defect sizes of < 1 cm²
and decreasing output
What are predictors that an EC fistula will require operative intervention?
Distal obstructions, ongoing sepsis or abscess, and malnutrition.
Which causes of EC fistulas are associated with a lower likelihood of spontaneous closure?
Fistulas caused by Crohn’s disease, malignancy, radiation, or a foreign body
How does the output of an EC fistula affect the likelihood of spontaneous closure?
Decreasing output increases the likelihood of spontaneous closure
Characteristics Predictive of Spontaneous Closure of Enterocutaneous Fistulas
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Characteristics Predictive of Spontaneous Closure of Enterocutaneous Fistulas
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When should surgeons consider operative management for EC fistulas that have not closed spontaneously?
At least 6 months after diagnosis to allow intraabdominal adhesions to soften
What is the purpose of the “pinch test” for EA fistulas?
To determine readiness for surgery by checking if tissue or skin graft overlying bowel separates easily.
What patient conditions should be met before surgery for EC fistulas?
Nutritional optimization, sepsis control, and the patient being close to their baseline functional status.
How should surgeons and anesthesiologists prepare for an EC fistula operation?
Prepare for a lengthy, difficult procedure with high insensible fluid losses, use a urinary catheter for accurate urine output recording, and consider epidural catheters or transversus abdominis blocks for pain management
Where should the surgical incision be made for an EC fistula operation?
Away from prior incisions, usually subxiphoid
What surgical technique is essential for managing adhesions in EC fistula operations?
Extensive lysis of adhesions with sharp dissection and full mobilization of the bowel.
What should surgeons document during an EC fistula surgery?
The amount of remaining bowel after resection
Why should fistula defects not be repaired primarily?
Because primary repair is likely to lead to recurrent leaks.
What approach should be taken if simple primary closure of the abdominal wall is not possible?
Use component separations or place biologic mesh in an underlay fashion
Who should be involved for complex abdominal wall defects during EC fistula surgery?
General surgeons or plastic surgeons specializing in abdominal wall reconstruction
What alternatives should be considered if the EC fistula cannot be safely resected?
Creating a diverting stoma or placing a venting gastrostomy tube and/or distal feeding jejunostomy tube
What is the current operative success rate for EC fistula takedowns?
Some studies report success rates as high as 92%
How has the mortality rate for EC fistula surgery changed since the 1970s?
It has decreased from approximately 40% to around 20%, with some studies citing rates as low as 2%
What is the 30-day morbidity rate for EC fistula surgery based on the American College of Surgeons dataset?
Nearly 50%
What is the typical duration of postoperative recovery for EC fistula surgery?
Several months, with gradual weaning off parenteral nutrition as enteral nutrition improves.
What postoperative care might EC fistula patients benefit from?
Postoperative physical therapy and, in some cases, stays in rehabilitation facilities
what Percentage with EC fistulas will recur after surgery
Approximately 16% to 36%
