Fistulae (the plural of fistula) are abnormal connections between 2 or more epithelium-lined hollow spaces or organs that result in communication between one body cavity or hollow organ and another hollow organ or the skin.1 Fistulae are often classified by location, involved structures, and volume of effluent. Caring for patients with fistulae is often complex, requiring an interprofessional approach that includes the Certified Ostomy Care Nurse (CWON), Certified Ostomy Care Advanced Practice Nurse (CWON-AP), and Ostomy Care Associate (OCA). Types of fistulae include enterocutaneous or enteric fistulae (ECFs), which are abnormal connections between the gastrointestinal (GI) system and the skin, and enteroatmospheric fistulae (EAFs), which occur in the setting of an open abdominal wound. Both may occur spontaneously or following surgery.2 Factors associated with spontaneously occurring fistulae include Crohn's disease, malignancy, radiation enteritis, ischemic bowel, mesh erosion, or trauma. Spontaneously occurring fistulae account for 25% of all ECFs and EAFs and rarely close on their own.1,3 The majority of ECFs and EAFs develop postoperatively due to an anastomotic leak or inadvertent injury to the small or large bowel. Other risk factors include malnutrition, traumatic injury, extensive lysis of adhesions, and postsurgical sepsis.

Medical management is the first line of treatment of fistulae, with an immediate focus on stabilizing the patient through sepsis control and fluid/electrolyte resuscitation. Next steps include defining the fistula anatomy, minimizing fistula output, containing the effluent, skin protection, and nutritional support. Collaboration between the patient, family, and the interprofessional team is essential in facilitating a comprehensive and effective approach to care.1,2

Spontaneous fistula closure is twice as likely to occur when nutrition is optimized.1,3 The goals of management are to provide adequate nutrition, maintain fluid levels and electrolyte balance, and support spontaneous closure of fistulae.1 Introduction of total parenteral nutrition (TPN) in the 1960s and “bowel rest” revolutionized the care of patients with ECFs and EAFs, but TPN is associated with increased rates of bacteremia and line sepsis.1,3 Enteral feedings should be considered first as they maintain GI mucosal immunity, integrity, and hormonal gut function. Total parenteral nutrition should be reserved for patients who cannot tolerate enteral feedings due to ileus, obstruction, or as a supplement to enteral feedings.1,2,4

Reducing fistula output decreases the incidence of malnutrition and fluid and electrolyte imbalance and protects the perifistular skin. Effective measures for decreasing fistula output include reducing oral and enteral intake to an amount that maintains healthy intestinal mucosa and introducing medications such as antidiarrheals, antimotility agents, and proton pump inhibitors. While somatostatin and its synthetic analogue, octreotide acetate, can decrease both fistula output and fistula closure time, neither drug has been shown to reduce mortality.1,2,4 Long-term use of octreotide has been associated with villous atrophy and acute cholecystitis and should only be used in the short term.1,2,4 Indicators of progress to closure include a decrease in fistula effluent, with increased fecal output distally through the stoma or rectum. Pseudostoma (also referred to as an epithelialized or stomatized fistula) development indicates that a permanent opening in the bowel has developed and requires surgical intervention.1,3,4

The fistula plan of care should focus on skin protection, containment of drainage, odor control, patient comfort and mobility, ease of care, and cost containment.1,2 The first step is a thorough assessment of abdominal or body contours, location of the fistula opening (if visible), quantity and characteristics of the effluent or drainage, and the condition of the perifistular skin. Absorptive dressings (gauze, alginates, hydrofibers, foams) and moisture barriers (liquid barrier films, moisture barrier ointments) are good options for nonodorous, low-output fistulae (<100 mL over 24 hours). Higher-volume fistulae usually require a containment device such as a pouch, closed suction, or negative pressure.1,2 Pouching options include fistula pouches, ostomy pouches (pediatric and adult), retracted penis pouches, and external fecal pouches. Bridging, saddle bagging, and troughing techniques can be helpful when the fistulae location or size prohibits direct placement of a pouch.1 Closed suction is a reliable and cost-effective method for managing high-output fistulae that are too difficult to pouch; however, it does require wall or portable suction and can severely limit patient mobility.1,2 Negative pressure wound therapy (NPWT) should be considered for management of an EAF or for an acute ECF. This therapy allows one to isolate the fistula with a pouch, while applying NPWT to the wound bed. Benefits include increased patient mobility and comfort, effective containment of effluent, maintenance of skin integrity, and decreased dressing changes.1–3

Fistulous openings can also occur between the bladder, rectum, small bowel, and vagina. These fistulae often require temporary urinary diversion (indwelling urethral or suprapubic catheter) or temporary fecal diversion, followed by surgery to remove the fistulous tract. Absorptive pads, moisture barriers, or placing a balloon-tipped catheter into the vaginal vault should be considered if the patient is not able to undergo surgery.1

Fistulae pose significant quality-of-life concerns for patients and management challenges for the interprofessional health care team.2 They are one of the most challenging and rewarding situations that the WOC nurse encounters. Key ingredients to a positive outcome are patience, persistence, collaboration, communication, and ingenuity.

1. Which products can be used to fill uneven surfaces around a high-output ECF?

Calcium alginate Moisture barrier cream Pectin barrier strip Negative pressure wound therapy

Exam content outline: 010402

Cognitive level: Application

ANSWER: C

Rationale: The answer is C. One goal of topical management of a fistula is skin protection and containment of effluent. Due to the amount of effluent from a high-output ECF, pouching is an excellent way to contain the drainage and protect the skin. Surgical scarring and uneven surfaces of the abdomen can make pouching a challenge. Pectin-based strips placed in the creases or around the pouch opening can fill in uneven surfaces and provide a physical barrier to effluent.1

2. Somatostatin has been known to decrease intestinal output from ECFs in certain situations. How is somatostatin administered?

Orally Subcutaneously Topically Intravenously

Exam content outline: 020503

Cognitive level: Recall

ANSWER: D

Rationale: The answer is D. In the exocrine system, somatostatin inhibits bile secretion, colonic fluid secretions, gastric acid secretion, pancreatic enzymes, cholecystokinin, and vasoactive intestinal peptide. However, due to the short half-life, it must be given intravenously.1 Synthetic analogues were created that mimic the action of somatostatin and can be given intravenously, subcutaneously, and intramuscularly. These analogues include larazotide, octreotide, seglitide, and vapreotide.2

3. Which of the following is the most important finding when considering using NPWT to promote closure of an ECF?

There is no evidence of abscess. The patient is on a liquid diet. The fistula has epithelial cells around the opening. There is no exposed bowel in the wound bed.

Exam content outline: 010207

Cognitive level: Recall

ANSWER: A

Rationale: The answer is A. Negative pressure wound therapy can be used to promote closure of fistula tracts. The patient must be NPO to decrease the amount of effluent. There can be no exposed bowel or evidence of abscess. The fistula must exhibit the potential for closure with no evidence of epithelial cells around the fistula or pseudostoma formation.1

4. A patient reports the passage of stool from her vagina. Which of the following is the most likely cause?

Colocutaneous fistula Vesicovaginal fistula Colovaginal fistula Enterocutaneous fistula

Exam content outline: 010207

Cognitive level: Recall

ANSWER: C

Rationale: The answer is C. A colocutaneous fistula is colon to skin. A vesicovaginal fistula is bladder to vagina. A colovaginal fistula is colon to vagina. An ECF is intestine to skin.1

REFERENCE 1. Nix D, Bryant R. Fistula management. In: Doughty DB, McNichol LL, eds. Wound, Ostomy and Continence Nurses Society Core Curriculum Wound Management. Philadelphia, PA: Wolters Kluwer; 2016:719.