1-s2.0-S1091255X05006049-main

Review Article

Current Management of Enterocutaneous Fistula

Amy R. Evenson, M.D., Josef E. Fischer, M.D., F.A.C.S.

Enterocutaneous fistulas, defined as abnormal communications between bowel and skin, are among themost challenging conditions managed by the general surgeon. In an era when the mortality from pan-creaticoduodenectomy is less than 3%, the mortality of enterocutaneous fistulas remains 10 to 30%due to the often-present complications of sepsis, malnutrition, and electrolyte abnormalities. Taking ad-vantage of recent advances in techniques of pre- and post-surgical management and support, employinga multidisciplinary team approach, and executing a well-delineated management plan provide the patientand surgeon with the best possibility of success in treating this potentially devastating condition.( J GASTROINTEST SURG 2006;10:455–464) � 2006 The Society for Surgery of the Alimentary Tract

KEY WORDS: Enterocutaneous fistula, sepsis, nutrition

CLASSIFICATION, ETIOLOGY,AND PREVENTION

Enterocutaneous fistulas may be categorized byanatomic, physiologic, or etiologic criteria, all ofwhich may influence the patient’s course and thelikelihood of spontaneous closure of the fistula(Table 1). Anatomic classifications divide fistulasinto internal and external fistulas, identify the organsinvolved, and provide characteristics of the fistulatract. Internal fistulas are connections between twohollow viscera that, if symptomatic or dangerous,should be treated by resection and reanastomosis.The focus of this review will be external fistulasthat adjoin hollow viscera to the skin. Favorableexternal fistula types include esophageal, duodenalstump, pancreaticobiliary, and jejunal fistulas withsmall enteric defects (!1 cm) and long tracts (O2cm). Gastric, lateral duodenal, ligament of Treitz,and ileal fistulas are less likely to close spontane-ously, as are fistulas associated with complete disrup-tion of intestinal continuity, adjacent abscess,strictured or diseased bowel, foreign bodies, or distalobstruction.1 Anatomic information is often the firstdata available and may allow the surgeon to predictthe patient’s ultimate need for surgical closure.

� 2006 The Society for Surgery of the Alimentary Tract

Published by Elsevier Inc.

The external loss of intestinal fluids rich in elec-trolytes, minerals, and protein contribute to thephysiologic complications of electrolyte imbalanceand malnutrition in patients with enterocutaneousfistulas. Fistulas may be high-output (O500 ml perday), moderate-output (200–500 ml per day), orlow-output (!200 ml per day).2 Accurate measure-ment of fistula output allows physiologic classifica-tion that assists in anticipating and providingappropriate metabolic support for these patients.Fistula output can also be used to predict mortalityas noted in the classic series by Edmunds et al.3 inwhich patients with high-output fistulas had a mor-tality rate of 54%, whereas patients with low-outputfistulas died in 16% of cases. In more recent series,Levy et al.4 report a mortality of 50% and 26% inhigh- and low-output fistulas, respectively.

The association between fistula output and closurerate is not as clear as that betweenoutput andmortality.However, a recent multivariate analysis of 188 patientsby Campos et al.5 revealed that patients with low-out-put fistulas (defined as!500ml/day) were three timesmore likely to undergo spontaneous closure thanthose with high-output fistulas. This was not thecase, however, in the largest series (404 patients)

From the Department of Surgery, Beth Israel Deaconess Medical Center, Boston, Massachusetts.Reprint requests: Josef E. Fischer, M.D., F.A.C.S., Beth Israel Deaconess Medical Center, Department of Surgery, 330 Brookline Avenue, Suite9F, Boston, MA 02215. e-mail: [email protected]

1091-255X/06/$dsee front matter

doi:10.1016/j.gassur.2005.08.001 455

mailto:[email protected]

456 Evenson and FischerJournal of

Gastrointestinal Surgery

published to date.6 Quantification of fistula outputallows more accurate management of the patient,and it may also provide prognostic information re-garding mortality and likelihood of eventual surgicaltherapy.

Determination of the etiologic factors involved infistula formation also allows prediction of the courseof the patient and likelihood of spontaneous closure.Fistulas may first be classified as spontaneous or post-operative, and typically reflect either diseased bowelextending to surrounding structures, normal bowelinvolved in extraintestinal disease, trauma to thebowel, or anastomotic breakdown. Spontaneousfistulas account for 15%–25% of all enterocutaneousfistulas and are likely to occur in the presence of can-cer or radiation, inflammatory conditions includinginflammatory bowel disease, diverticular disease,appendicitis, and perforated ulcer disease or ischemicbowel.1 Of these conditions, cancer and inflammatory

Table 1. Predictive factors for spontaneous closureand/or mortality

Factor Favorable Unfavorable

Organ of origin Esophageal GastricDuodenal stump Lateral duodenalPancreatic, biliary Ligament

of TreitzJejunal IlealColonic

Etiology Postoperative(anastomoticleakage)

Malignancy

Appendicitis Inflammatorybowel disease

DiverticulitisOutput Low (!200–500

ml/day)High (O500ml/day)

Nutritional status Well nourished MalnourishedTransferrinO200 mg/dL

Transferrin !200mg/dL

Sepsis Absent PresentState of bowel Intestinal

continuityDiseased adjacentbowel

Absence ofobstruction

Distal obstruction

Large abscessBoweldiscontinuity

Previousirradiation

Fistula Tract O2 cm Tract !1 cmcharacteristics Defect !1 cm Defect O1 cm

Miscellaneous Original operationperformed atsame institution

Referred fromoutsideinstitution

bowel disease are most common. Fistulas resultingfrom malignancy or radiated bowel are unlikely toclose spontaneously, whereas those resulting from in-flammatory bowel disease may close only to reopenupon resumption of enteral feeding.6,7 Knowledgeof the etiology of spontaneous fistulas, therefore,may lead to earlier surgical therapy.

The majority of enterocutaneous fistulas (75%–85%) are postoperative. Procedures performed formalignancy, inflammatory bowel disease, or adhe-siolysis are the most common operations antecedentto the development of enterocutaneous fistulas.2

Factors contributing to the development of postop-erative enterocutaneous fistulas may be classified aspatient-specific or technique-specific. Specific riskfactors for patients include operation for the previ-ously listed conditions, previous radiation therapy,malnutrition, infection or sepsis, and operations inan emergency setting with possible concomitant hy-potension, anemia, hypothermia, or poor oxygen de-livery. For elective operations, control of infectionand improvement of nutrition may be possible, butfor emergency operations, one can only hope to op-timize resuscitation and perfusion and performa technically meticulous procedure.

Specific techniques to decrease the incidence ofpostoperative enterocutaneous fistulas are those ofsound surgical practice. Preoperatively, the nutri-tional status of the patient should be assessed. Patientswith a recent 10%–15%weight loss, an albuminof lessthan 3.0 grams per deciliter, or low transferrin or totallymphocyte levels (although this is less well proven)are at increased risk for poor healing and possibleanastomotic dehiscence. Patients should be normovo-lemic and not anemic to optimize oxygen delivery.Preoperative skin preparation, mechanical and antibi-otic bowel preparation, and systemic antibioticsdecrease the risk of infection, abscess, and therefore,fistula formation. During the procedure, the sur-geon’s emphasis should be on avoiding tension, ensur-ing adequate blood supply, and using nondistended,nondiseased bowel for anastomosis.1 Additionally,meticulous hemostasismust be achieved, and inadver-tent enterotomies and serosal injuries should beidentified and repaired. If possible, the anastomosisshould be shielded from the incision by an omentalflap. Finally, a secure abdominal wall closure shouldbe performed, taking care to not injure underlyingbowel.7 In the postoperative period, adequateoxygen-carrying capacity should be maintained andnutritional support provided as necessary. In cases ofsignificant contamination, antibioticsdas therapeuticagentsdshould be continued briefly in the postoper-ative period (24–48 hours). Given the complex physi-ologic and management challenges created by

Vol. 10, No. 32006 Current Management of Enterocutaneous Fistula 457

postoperative enterocutaneous fistulas, use of soundsurgical technique in preventing this catastrophiccomplication is paramount.

COMPLICATIONS

Edmunds et al.3 identified the classic triad of com-plications of enterocutaneous fistula as sepsis, mal-nutrition, and electrolyte and fluid abnormalities.The presence of bowel contents outside the lumenmay lead to localized abscess, soft tissue infection,generalized peritonitis, or frank sepsis, dependingon whether the bowel leak communicates with theperitoneal cavity or soft tissues. Early control of fis-tula output, drainage of localized collections, and ap-propriate antibiotic therapy are keys in the earlymanagement of these patients. In a recent large se-ries, Campos et al.5 reported that the presence of in-fectious complications increased the odds ratio ofdeath by 22-fold. Most recent series suggest that sep-sis, with its concomitant malnutrition, is the leadingcause of death in patients with enterocutaneousfistulas.5,6,8

Postoperative ileus, the loss of bowel integrity andabsorptive surface area, and the external loss of pro-tein-rich enteric contents all contribute to the mal-nutrition and fluid and electrolyte abnormalitiesseen in patients with enterocutaneous fistulas. Evenin an era when rapid, accurate determination of se-rum electrolytes is available, disorders of electrolytesare frequently present for greater than 24 hours, per-haps reflecting the difficulty in ‘‘keeping up’’ withfistula losses. Identifying the source of the fistulawill allow a rough estimate of the composition ofthe fluid lost. In complex situations, analysis of fis-tula-output electrolyte composition may aid in main-taining normal levels of important electrolytes,including sodium, magnesium, potassium, phos-phate, bicarbonate, and calcium.

Further complicating the scenario, septic patientsare extremely hypercatabolic and are unable toachieve positive nitrogen balance, regardless of theprovision of artificial nutrition. In the series of Hillet al.,9 patients with uncontrolled sepsis lost 2% ofbody protein stores per day, even though they werereceiving parenteral nutrition. Over the course oftwo weeks, these patients lost 1.4 kg of body protein(24% of total) despite the gain of 1.9 kg of fat.9

Developing a plan to control sepsis and provideadequate nutrition through a combination of enteraland/or parenteral nutrition is a key element to man-agement of these patients.

The provision of total parenteral nutrition hasbeen associated with an increased rate of

spontaneous closure of fistulas in several series.6,9–12

In patients requiring surgical closure of their fistu-las, any improvement in the nutritional status willaid in maintaining bowel continuity by promotingwound healing, enhancing the immune system,and preserving lean cell mass. Nutritional status isan important predictor of mortality in patientswith enterocutaneous fistulas. Fazio et al.8 reportedno mortality in patients with serum albumin levelsgreater than 3.5 g/dL, whereas those with albuminlevels less than 2.5 g/dL experienced a mortalityrate of 42%. Similarly, serum transferrin level wasrecently reported to predict both mortality and therate of spontaneous closure of enterocutaneous fis-tulas, whereas retinol-binding protein and thyroxin-binding prealbumin predicted only mortality.13

Interestingly, in this group of patients, serum albuminpredicted neither mortality nor spontaneous closure.

MANAGEMENT

When approaching any complex situation, the useof a detailed, multidisciplinary plan aids in manage-ment. The following five steps represent a progres-sion from identification and stabilization of thepatient, investigation into the type and character ofthe fistula, decision making regarding the need forsurgery, definitive surgical repair, and promotionof healing. The ultimate goal is to restore the integ-rity of the patient’s gastrointestinal tract and allowenteral nutrition while minimizing morbidity andmortality (Table 2).

Stabilization

Identification. Typically, the patient with an en-terocutaneous fistula has had a poor early postoper-ative course complicated by fevers and a prolongedileus. Toward the end of the first postoperativeweek, wound erythema has developed. The woundhas been opened and drained purulent fluid, fol-lowed shortly by enteric contents. At this point, thepatient has suffered multiple stresses, including thedisease process leading to operation, a preoperativebowel preparation, the surgical stress of the proce-dure, and a prolonged postoperative course nowcomplicated by sepsis and the metabolic conse-quences of the fistula. The patient has typically lostlean body mass due to this prolonged period of noor limited nutritional support. The patient is likelyto be dehydrated, anemic, and have low levels ofthe major serum oncotic proteins including albumin.

Resuscitation. Restoration of circulating volume isthe first goal. Crystalloid resuscitation may requireseveral liters to correct for losses into the bowel



Table 2. Management phases

Phase Goal Time course

Recognition/stabilization Resuscitation 24–48 hoursCrystalloid, colloid, blood

Control of sepsisCT-guided or open drainage, antibiotics

Electrolyte repletionProvision of nutritionControl of fistula drainageCommencement of local skin care/protection

Investigation Fistulogram to define anatomy and characteristicsof fistula

7–10 days

Decision Evaluate likelihood of spontaneous closureEtiology, anatomy, drainage output

Decide duration of trial of nonoperative management 10 days to 6 weeksDefinitive therapy Plan operative approach When closure unlikely or after

4–6 weeksRefunctionalization of entire bowelResection of fistula with end-to-end anastomosisSecure abdominal closureGastrostomy/jejunostomy

Healing Continue nutrition support until full oral nutritionis achieved by patient

Starting 5–10 days after closureuntil full oral nutrition

Zinc supplementation

wall and third spaces. Transfusion of red blood cellswill improve oxygen-carrying capacity, whereas infu-sion of albumin will help restore plasma oncoticpressure. Caution should be exercised in patientswith sepsis-induced capillary leak, as albumin maywors respiratory parameters due to accumulationin the pulmonary interstitium. In patients at risk ofpulmonary or cardiac embarrassment, placement ofa central venous pressure monitor or pulmonary ar-tery catheter may aid in resuscitation.

Control of sepsis. Concurrent with resuscitation,evaluation for treatable foci of sepsis should be aprimary goal during this phase of management.Computed tomography may assist in revealing intra-peritoneal abscesses that may then be percutaneouslyor operatively drained. Proximal diversion may beconsidered if operative drainage is required, but de-finitive resection and repair of the fistula should bedeferred due to the high probability of recurrencein the setting of emergency surgery in a septic pa-tient. In draining abscesses, the surgeon should con-sider injection of water-soluble contrast into theabscess cavity as a means of identifying the fistuloustract and its communication with the bowel. Under-standing that any manipulation of septic foci maylead to bacteremia, central venous catheters shouldnot be placed for 24 hours following drainage. Mate-rial from the abscess should be sent for microbio-logic culture.

Septic patients should be treated initially with em-piric antibiotics that are then tailored to the specificpathogens identified. The presence of an enterocuta-neous fistula without evidence of sepsis (high fever,rigors, and hypotension) or a localized infection (cel-lulitis, pneumonia, etc.) does not warrant antibiotictherapy. Indiscriminate use of prophylactic antibi-otics in patients with enterocutaneous fistulas willlead to the emergence of highly resistant bacteria.Special consideration should be given to the treat-ment of fungal infections in patients with enterocu-taneous fistulas. In patients with yeast culturedfrom two or more sites, a low threshold for use ofamphotericin B should be maintained.

Nutritional support. The provision of nutritionalsupport is a key component of the stabilizationphase. As previously discussed, patients with entero-cutaneous fistulas are often malnourished due to thelack of food intake, the hypercatabolism of sepsis,and the loss of protein-rich enteral contents. Aftersepsis has been controlled, the metabolic needs ofthe patient are considered. The patient’s current nu-tritional status should be assessed using such tools asthe bedside subjective global assessment,14 baselinelaboratory values, anthropometric analysis, and po-tentially new techniques such as multiple-frequencybioelectric impedance analysis.15,16 Once baselineassessment has occurred, the patient’s estimatedmetabolic needs should be calculated. Traditionally,


the Harris-Benedict equations and use of the appro-priate stress factor have provided a meaningful start-ing point for nutritional support. More recent use ofmetabolic cart analysis (indirect calorimetry) allowsfor assessment of the respiratory quotient and appro-priateness of the macronutrient balance. In our expe-rience, patients with enterocutaneous fistulasgenerally require 25 to 32 kcal/kg per day in totalcalories with a calorie-to-nitrogen ratio of 150:1 to200:1 and a protein intake of at least 1.5 g/kg perday. As many authors have noted, formulas providea convenient starting point for estimating the nutri-tional requirements of patients with enterocutaneousfistulas, but ongoing clinical assessment with adjust-ment according to the patient’s course is essential inmanaging these complex situations.

Parenteral nutrition has long been recognized tobe an integral part of the management of enterocu-taneous fistulas.6,11,12 Our own experience and sev-eral recent series report the use of enteral nutritioneither in combination with parenteral nutrition oras a primary means of nutritional support.4,17

Whereas 85% of Levy’s patients with high-outputsmall bowel fistulas were able to be sustained on en-teral nutrition alone, the provision of only 20% ofcalories fed enterally may protect the integrity ofthe mucosal barrier as well as the immunologicand hormonal function of the gut. Enteral feedingalso improves hepatic protein synthesis. As patientsoften do not reach caloric support goals via the en-teral route for several days after starting the feed-ings, it is prudent to commence both parenteraland enteral support early in these patients, withthe plan to cease parenteral support if enteral feed-ing goals are met. In cases of proximal fistulas, feed-ings may be infused into the fistula if there issufficient distal small bowel length (approximately4 feet) and no distal obstruction. Newer enteralformulations containing supplements, including glu-tamine, arginine, omega-3 fatty acids, and nucleo-tides, may provide immune-enhancing effects incritically ill patients, but studies in this populationhave not yet been reported.

Except for extremely high-output fistulas, theprovision of electrolytes via parenteral or enteralnutrition is adequate. Although knowledge of thesource of fistula output may allow estimation of thecomposition of the losses, the effluent may be a com-bination of secretions from sites proximal and distalto the fistula.18 Vitamins and trace minerals are oftendeficient in malnourished patients with enterocuta-neous fistulas. We often provide twice the recom-mended daily allowance of vitamins and traceminerals, and up to 10 times the recommended dailyallowance for vitamin C and zinc. For long-standing

small bowel fistulas, supplemental copper, folic acid,and vitamin B12 may be necessary.

Control of fistula drainage. Many authors haverecommended the use of long-term nasogastricdrainage as a means to decrease fistula output. Inthe absence of obstruction or prolonged ileus, how-ever, there is little evidence that nasogastric drainageis beneficial. Nasogastric tubes may instead contrib-ute to sinusitis, gastroesophageal reflux, pulmonaryaspiration, and patient discomfort. Use over a pro-longed course may also place patients at risk of lateesophageal strictures.

Acid suppression with H2-receptor antagonists orproton-pump inhibitors may decrease the volumeand acidity of gastric secretion. Although these inter-ventions have not been shown to increase the rate offistula closure, acid suppression may aid in the pre-vention of gastritis and stress ulceration, whereas de-creasing fistula output will allow easier control ofelectrolyte and acid-base imbalances. Anothermethod for decreasing gastric acidity is the use of su-cralfate; this agent also has the ability to constipate,thereby decreasing fistula output as well.

Somatostatin and its analog, octreotide, inhibitthe endocrine and exocrine secretion of many gas-trointestinal hormones, including gastrin, cholecys-tokinin, secretin, insulin, glucagon, and vasoactiveintestinal peptides.19 Additionally, somatostatin andits analogues inhibit gastric acid secretion, pancre-atic exocrine secretion, and intestinal and gallblad-der motility and contractility. The potential role ofsomatostatin and octreotide in the treatment of en-terocutaneous fistulas is obvious; unfortunately, theuse of these substances in management of patientshas not significantly improved outcome.20,21 Ran-domized controlled trials comparing the use of so-matostatindin combination with conservativemeasures including total parenteral nutrition (TPN)to conservative measures aloneddemonstrated aninconsistent decrease in fistula output and time toclosure but did not increase the rate of nonoperativeclosure.22 Randomized controlled trials comparingthe use of octreotide with nonoperative therapy sim-ilarly failed to demonstrate a consistent decrease infistula output, time to closure, or closure rate.23–25

Additional problems related to somatostatin use in-clude the need for a continuous intravenous infusion,the frequent incidence of hyperglycemia, and signifi-cant rebound effect when discontinued.20 The use ofoctreotide allows subcutaneous dosing on a two orthree times per day schedule and does not seem tobe associated with hyperglycemia. Both hormonesare associated with an increased incidence of choleli-thiasis. In summary, although these hormones maydecrease fistula output and therefore simplify the



management of enterocutaneous fistulas, evidencefrom randomized controlled trials does not indicatetheir use in the routine care of fistula patients.

Recent success in the treatment of perianal fistuliz-ing Crohn’s disease has lead to interest in the use ofinfliximab, a chimeric monoclonal antibody to tumornecrosis factor a, in patients with enterocutaneous fis-tulas. Present et al.26 reported a randomized con-trolled trial enrolling 94 patients with abdominal(10%) and perianal (90%) fistulas secondary toCrohn’s disease, which had been present for at least3 months. In this population, a significantly largerproportion of patients receiving infliximab had a re-duction in the number of draining fistulas at follow-up than control patients. As 90% of these patientshad perianal fistulas, and all fistulas had been presentgreater than 3 months, the applicability of these re-sults to the patients with typical enterocutaneous fis-tulas described throughout this review is limited. Asmaller study of seven patients with enterocutaneousfistulas in the setting of refractory pouchitis followingileal pouch-anal anastomosis for ulcerative colitisrevealed encouraging preliminary results.27 In this se-ries, six of the seven patients had a complete symptom-atic response, whereas five had complete fistulaclosure after 10 weeks of follow-up.27 Although en-couraging, this is a small, nonrandomized study ina highly selected population. Side effects reported inthese studies included headache, abscess, upper respi-ratory tract infection, and fatigue. Of concern in typ-ical enterocutaneous fistula patients, infliximab shouldnot be used in the setting of clinically important, acuteinfections. The role of infliximab in the managementof enterocutaneous fistulas remains to be resolved.

Protecting the integrity of the skin surroundinga fistula will decrease local irritation and infection.Further, an intact abdominal wall will aid in secureclosure of the abdomen should operation be re-quired. There have been many methods reportedfor the management of fistula drainage, includingsimple gauze dressings, skin barriers, pouches, andsuction catheters. If the fistula output is low, simpleabsorbent dressings may suffice. However, in morecomplicated cases, karaya powder or seal, Stomahe-sive (ConvaTec, Victoria, Australia), glycerin, orion exchange resins may be needed to protect theskin from maceration and breakdown. A sump drainconstructed from a Robinson nephrostomy cathetervented using a 14-gauge Angiocath provides effectivedrainage for most fistulas (Fig. 1). A skilled enteros-tomal therapist can significantly contribute to thecare of patients with enterocutaneous fistulas.

Several authors have reported the use of vacuum-assisted closure (VAC) systems in managing entero-cutaneous fistulas. Erdmann et al.28 reported the

successful use of a VAC dressing in treating a smallbowel fistula draining 200–500 ml per day. After 4weeks of every-other-day dressing changes, the fis-tula output had decreased to less than 30 ml perday, and the fistula was completely closed by 8 weeksof treatment. Alvarez et al.29 reported a patient whodeveloped an enterocutaneous fistula during chemo-therapy for ovarian cancer. A VAC dressing was ap-plied with daily dressing changes, resulting inclosure of the fistula by 2 months of treatment. Croet al.30 reported a series of three patients with high-output small bowel fistulas (300 ml/day to over 1000ml/day). After treatment of the fistulas with a VACdressing system, all three patients experienced signif-icant decreases in fistula output within 4 weeks oftreatment, and two of the three fistulas resolved with-out surgical intervention. When a fistula is large anddifficult to dress, a VAC system may make skin careeasier (Fig. 2). Although these cases are encouraging,itmust be noted that the use of theVAC system on en-terocutaneous fistulas is considered experimental andshould be used with caution.

Investigation

Once the patient has been resuscitated and stabi-lized, investigation into the course and nature of the

Fig. 1. Construction of a wound sump. A Robinson nephros-tomy catheter is placed in the wound near the fistula opening.The catheter is vented with a 14-gauge Angiocath and con-nected to wall suction. The catheter is sutured to the woundedges and covered with gauze or a VAC dressing.


Fig. 2. Use of VAC dressing in the management of an enterocutaneous fistula. In this patient, we useda VAC dressing to manage wound drainage. Additionally, tube feeding into the distal fistula providednutrition during this stage of management of the fistula. The dressing change initially took two totwo and one half hours and was performed every 3 to 5 days. Operative closure of the fistula was success-ful and was combined with a flap abdominal wall closure. (A) Demonstrates the multiple fistula open-ings, a distally placed feeding tube, and surrounding DuoDerm and stoma glue. (B) Demonstratesthe VAC dressing in place with suction applied.

fistula should be undertaken. Some authors recom-mend enteral use of methylene blue as a ‘‘roughand ready’’ test to confirm the presence of an entero-cutaneous fistula and to determine whether the leak isfrom a segment of bowel in continuity with the rest ofthe digestive tract versus a leak from a segment not incontinuity.31 The methylene blue test does not pro-vide significant anatomic information and is not oftenused in our practice.

After 7 to 10 days, the patient has generally stabi-lized, and the fistula has matured to the point of sup-porting intubation of thin catheters in all orifices. Atthis point, the patient should undergo fluoroscopicfistulography with water-soluble contrast under thedirect supervision of a senior radiologist and the se-nior surgeon responsible for the patient’s care. Theinformation gained by such a study includes (1) thesource of the fistula; (2) the nature (length, course,and relationships) of the fistula tract; (3) the absenceor presence of bowel continuity (end vs. side fistula);

(4) the absence or presence of distal obstruction; (5)the nature of the bowel adjacent to the fistula(inflammation, stricture); and (6) the absence orpresence of an abscess cavity in communicationwith the fistula.32

The fistulogram provides information not obtain-able through any other study, and early films can beparticularly useful in defining anatomy and relation-ships. As previously discussed, water-soluble contrastmay also be injected into abscesses at the time ofdrainage as a type of early fistulogram.

As discussed previously, in a septic patient CT canidentify abscesses and may guide percutaneousdrainage. Fistulas are not often seen distinctly onaxial CT. However, data derived from the use of sag-gital or three-dimensional reconstructions may behelpful. Upper gastrointestinal studies and bariumcontrast enemas rarely provide information not ob-tained via fistulography. When considering the useof multiple contrast studies, the order of the tests



needs to be considered, as retained contrast maylimit the utility of subsequent studies.

Decision

Ideally, the provision for adequate nutrition in pa-tients free of sepsis will result in closure of enterocu-taneous fistulas within 4 to 6 weeks. Unfortunately,spontaneous closure occurs only in about 30% of pa-tients. It is possible to identify anatomic, etiologic,and functional characteristics of fistulas that are un-likely to close spontaneously (Table 1). Fistulas ofthe stomach, ileum, and ligament of Treitz are lesslikely to close spontaneously, as are fistulas associ-ated with large abscesses, short fistula tracts, largeopenings in the bowel, damaged or strictured intes-tine, intestinal discontinuity, or distal obstruction.In these cases, if closure or signs of imminent closure(decrease in output) do not occur after 4 weeks, plansfor operative resection should be made. Fistulas as-sociated with cancer, radiation, or inflammatorybowel diseases are also unlikely to close or remainclosed without surgical intervention. In the case ofinflammatory bowel disease, should the fistula closespontaneously, definitive resection and reanastomo-sis should be performed to avoid recurrence. Simi-larly, fistulas occurring in the setting of cancershould be resected with consideration of intraopera-tive radiation, if appropriate. One etiology of fistulasthat has become more common is erosion of previ-ously placed Marlex mesh. In a recent case of fistuli-zation involving Marlex mesh, resection of the meshallowed spontaneous fistula closure.

In planning for operative management of entero-cutaneous fistulas, the surgeon must balance the ad-equacy of nutritional support, the likelihood ofspontaneous closure, and the likelihood of the tech-nical feasibility of the procedure. Fazio et al.8 de-scribed the ‘‘obliterative peritonitis’’ that occursduring the period from approximately 10 days to 6weeks following laparotomy in patients with entero-cutaneous fistulas associated with sepsis. Althoughselection bias was clearly involved, patients whowere operated on within 10 days of their originalsurgery and those whose operations were delayedat least 6 weeks had mortality rates of 13% and11%, respectively.8 In contrast, patients requiringrelaparotomy during the period between 10 daysand 6 weeks of their initial surgery suffered a mortal-ity rate of 21%.8 Soeters et al.6 similarly recommen-ded providing nutritional support during this periodto allow the ‘‘future operative field to become quies-cent.’’ Ninety to 95% of fistulas that will spontane-ously resolve do so postoperatively within the first4 to 5 weeks. Delaying an operation this long will

both allow those fistulas that are likely to close anopportunity to do so, while at the same time decreas-ing the risks of multiple enterotomies and difficultdissection in the immediate postoperative period.12

Our own practice generally tries to wait at least 4months from the previous operation. This does notprolong the wait, as most of the patients in this prac-tice are transferred from other facilities and requireweeks of preparation for nutritional parameters toimprove so that operation can be carried out safely.Our own operative mortality for an elective opera-tion in patients with fistulas is less than 2%, despitethe length of operationdoften 8 hours.

Definitive Therapy

The decision to operate on a patient for resolu-tion of an enterocutaneous fistula represents a signif-icant commitment of time, energy, and resources.The surgical team should be well rested and havea 6 to 8 hour block of time to dedicate to the case.The patient should have achieved optimal nutritionalstatus and should be free of all sources of sepsis. Ahealed abdominal wall with minimal inflammationwill afford the most secure closure. Enteral tubefeedings should be decreased in the days precedingoperation to allow luminal antibiotic preparation.Microbiologic data should be reviewed and appro-priate antibiotic prophylaxis administered.

At operation, the abdomen should be enteredthrough a new incision far from any areas of poten-tial sepsis. A transverse incision often offers the bestopportunity of entering the abdomen in an area freeof dense adhesions. If use of the prior midline inci-sion is required, the abdomen should be entered ei-ther above or below the extent of the previousincision. Either approach minimizes the risk of cre-ating enterotomies while attempting to gain accessto the peritoneum. Once the peritoneum has beenentered, either wound towels or wound protectorsshould be employed to protect the tissues of the ab-dominal wall from contamination.

The goal of the next and main stage of the oper-ation is to free the entire bowel from the ligament ofTreitz to the rectum. Exploration of the bowel inthis manner ensures that all abscesses and sourcesof obstruction are identified and resolved to avoidfailure of the present anastomosis. Some authors ad-vocate commencing dissection at the ileum andworking proximally. In general, the pattern of adhe-sions may guide the operation with effort concen-trated on the ‘‘easiest’’ sections first. Application ofantibiotic-soaked laparotomy pads to areas of denseadhesions creates edema that facilitates further dis-section. Dissection of adhesions should be


performed sharply using a combination of scalpeland scissor dissection. Placing the operating sur-geon’s left hand behind the adhesions and cuttingthem from the side provides a controlled environ-ment to further protect the bowel from inadvertententerotomy.

Upon isolation of the segment of bowel contain-ing the fistula, optimal management requires resec-tion of the diseased segment. If multiple loops ofbowel are involved in the fistula, they are most oftenadjacent, facilitating management. Exteriorization,bypass, Roux-en-Y drainages, and serosal patches,typically using jejunum, are options for difficult casesbut do not provide optimal results. The creation ofa two-layer, interrupted, end-to-end anastomosis us-ing healthy bowel and nonabsorbable sutures maxi-mizes the likelihood of a secure anastomosis. Uponcompletion of the resection and anastomosis, the en-tire bowel surface is inspected to identify serosaltears or enterotomies. Serosal tears are repaired us-ing nonabsorbable Lembert sutures, usually a mono-filament 4.0 or 5.0 suture. Closure of full-thicknessenterotomies is in the manner of Heineke-Mikulicz.Meticulous attention to detail in reoperative surgeryincreases the odds of a good outcome.

Prior to closure of the abdominal wall, extensiveperitoneal irrigation with antibiotic solution is per-formed. If available, the omentum may be placed be-tween the fresh anastomosis and the peritonealclosure. Placement of a decompressive gastrostomyand a feeding jejunostomy will aid in the postopera-tive management of most patients undergoing proce-dures of this magnitude. Closed suction drainagemay be considered in particularly difficult cases.Seprafilm is a useful adjunct to minimize futureadhesions.

Secure abdominal wall closure is paramount toprevent recurrence of fistulization. Maintenance ofan infection- and inflammation-free abdominalwound during the preoperative period may allowfor primary closure of the incision. If a difficult clo-sure is anticipated, the involvement of the plastic andreconstructive surgical service in the planning ofsuch a procedure is advised. The undertaking ofa complicated myocutaneous flap procedure is bestleft to a fresh team after a difficult abdominaldissection.

Healing

Whether closure occurs spontaneously or by op-erative means, continued nutritional support is es-sential for maintenance of intestinal continuity andabdominal wall closure. Healing requires positive ni-trogen balance, and the cessation of adequate caloric

and protein support in the early postoperative periodoften results in the degradation of newly synthesizedprotein. The provision of supplementary nutrition isadvised until the patient is able to consistently con-sume 1500 kilocalories by mouth. Passage throughthe traditional steps of dietary advancement (clearliquids, full liquids, soft diet, and full diet) is unlikelyto be tolerated by these patients. Instead, startinga soft diet approximately 1 week postoperativelyand inviting family members to bring in the patient’sfavorite foods may increase the patient’s desire toeat. Similarly, cycling tube feedings to run overnightmay increase the patient’s appetite during the day.Finally, the provision of zinc supplementation with220 mg per day may improve or restore the patient’ssense of taste and increase food intake.

CONCLUSIONS

Knowledge of the pathophysiology and risk fac-tors for the development of enterocutaneous fistulasmay optimize the ability to avoid their creation inthe first place. Once this catastrophic complicationoccurs, the best outcomes result from a rational,well-defined management protocol. Early diagnosisof the fistula and resuscitation of the patient, thecontrol of sepsis, and the provision of nutritionalsupport may limit the morbidity and mortality asso-ciated with this complication. After adequate stabili-zation, investigation and an attempt at nonoperativemanagement may allow for spontaneous closure ofthe fistula, thus avoiding the risks of a major reoper-ative procedure. Should operative intervention be re-quired, careful planning and meticulous execution ofthe resection, reanastomosis, and reconstruction ofthe abdominal wall maximize the patient’s chancesof successful resolution. Attention to postoperativemaintenance of adequate nutrition during the transi-tion back to oral feedings ensures the durability ofthe repair. Solid, evidence-based surgical and perio-perative management may allow restoration of thepatient to a functional and productive role in society.

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