Topical Management of Enterocutaneous and Enteroatmospheric Fistulas: A Systematic Review

Enterocutaneous (ECF) and enteroatmospheric (EAF) fistulas are associated with considerable morbidity and patient care challenges, including optimal topical management. Purpose: A systematic literature review was conducted to identify topical management interventions used in ECF/EAF care and to explore the role of these interventions in fistula closure and long-term fistula management. Methods: A search of  PubMed, the Cumulative Index of Nursing and Allied Health Literature, and Scopus was conducted to identify English-language articles published from January 2004 to January 2019. The keywords enterocutaneous fistula, enteroatmospheric fistula, negative pressure wound therapy, NPWT, vacuum-assisted closure, VAC, pouch or pouching, troughing, bridging, collection device, dressing, and wound care were used to identify all publications pertaining to the topical management of adult and mixed adult/pediatric patients with an ECF or EAF. Single-person case studies, exclusively pediatric studies, surgical treatment-based, and duplicate publications were excluded. Abstracts were screened for relevance to the research questions, and eligible publications were abstracted and categorized using The Oxford Centre for Evidence-Based Medicine Levels of Evidence. The Joanna Briggs Institute (JBI) critical appraisal checklist for case series was used to assess each article for risk of bias and methodological quality. Outcomes of interest included patient demographics, closure rates, fistula classification (type of fistula, fistula output, fistula origin), type of topical treatment, adverse events (pain, new fistula formation, fistula recurrence, mortality), follow-up, long-term management, perifistula skin protection, effluent management, dressing change frequency, and quality of life. Descriptive statistics were presented; no statistical analysis was performed. Results: Of the 983 articles identified, 57 underwent critical appraisal using the JBI checklist for case series. Forty-two (42) did not meet the inclusion criteria, leaving 15, level IV, case-based publications (N = 410 patients). No randomized controlled trials were found. All studies included some form of negative pressure wound therapy. JBI results found that each study was at high risk of bias in more than 2 domains. Interventions were categorized as intubation, occlusion, or isolation of the fistula. Of the 559 fistulas treated, spontaneous closure was reported in 164 cases, with rates ranging from 0% to 100%. Adverse events to treatment included pain (n = 33 patients), new fistula formation (n = 12), and fistula recurrence (n = 1). Sepsis was the leading cause of mortality (n = 29), with reported rates ranging from 0% to 44%. Conclusion: Due to the high risk of study bias and low quality of evidence, the exact contribution of any one intervention could not be established. Results also suggest a high risk of publication bias, and patient-centered outcomes were reported in only 1 study. Although topical management might play a role in fistula closure, it is only as part of a comprehensive plan of care. Future research should focus on developing and using standardized reporting tools, classifications, and outcomes and include patient-centered outcomes such as acceptance, tolerability, pain, and quality of life relating to any one intervention. At this time, the evidence base for management recommendations is limited, suggesting that interventions should mainly be based on practical considerations such as resources and clinician skill.

An enterocutaneous fistula (ECF) is an abnormal communication between the small or large bowel and the skin of the abdomen.¹ An enteroatmospheric fistula (EAF) is a type of ECF where, in the absence of overlying soft tissue, the fistula opens to the exposed viscera of an open abdomen.² A literature review³ and a retrospective study⁴ of 277 patients with a fistula found an estimated 75%³ to 85%^3,4 of ECFs are iatrogenic and arise as a complication of abdominal surgery, after an anastomotic leak, or unintentional intestinal disruption.³ EAFs also occur as a postoperative complication and are unique to the open abdomen procedure.⁵ The remaining 15%^3,4 to 25% of ECFs occur spontaneously, with inflammatory bowel disease and malignancy the primary underlying causes.³

In both fistula presentations, the aberrant opening allows for the free passage of gastric contents to the external environment,¹ which according to a systematic review⁶ of patients with ECFs/EAFs, results in the loss of large amounts of fluids, electrolytes, and visceral proteins. Two (2) literature reviews found that exposure of the skin, granulation tissue, or open abdomen tissue to the high enzymatic and low pH content of the gastric effluent frequently causes breakdown of the exposed cellular structures.^7,8 In a case series⁹ of 2 patients, denudation and maceration of the surrounding perifistula skin was found to occur within 6 hours of exposure. Retrospective data¹⁰ of 1028 patients with a fistula and 1 case review¹¹ found that ineffective containment of fistula effluent can lead to abscess formation and peritonitis. Ongoing inflammation triggered by effluent and underlying infectious processes cause the fistula to undergo local changes and increase in size.¹⁰ According to a literature review,1² over time, the orifice epithelializes, develops a fibrous scaffold, and reaches maturation.

Although ECFs and EAFs have unique presentations, topical management research is inconsistent in differentiating these 2 pathologies9^,13-17 and they will be combined as ECFs/EAFs for the remainder of this review.

Fistulas are commonly classified by etiology, location, output,^3,18 and maturity.¹⁸ Output volume is a commonly used method of ECF/EAF classification and typically characterized as high (>500 mL/24 hours), moderate (200 mL/24 hours to 500 mL/24 hours), or low (<200 mL/24 hours).^3,18 A prospective study¹⁹ of 79 patients with a fistula found a common ECF/EAF management approach includes the restoration of fluid and electrolytes, management of sepsis, nutritional support, wound management and output reduction, definition of the fistula anatomy, and/or definitive surgical intervention. Following these management principles can cause the fistula to close spontaneously. Prospective research²⁰ involving 188 patients with a fistula and retrospective data²¹ of 277 adult patients with a fistula showed that with patient optimization, spontaneous closure occurred in approximately 37% to 50% of cases, respectively. Persons who do not achieve spontaneous closure will either undergo surgical repair^20,21 or will have a fistula long-term.^15,18 A recent systematic review and meta-analysis² confirmed that spontaneous closure is the preferable outcome, because surgical closure increases the risk of fistula recurrence. A retrospective risk study²² of 135 adult patients with a fistula estimated this complication occurs at a rate of 17% and is a strong predictor of mortality.

Topical management of ECFs/EAFs typically refers to the containment of effluent and the protection of perifistula tissue.²³ Retrospective case data¹⁰ of 1028 patients with a fistula and an early fistula publication²⁴ state that before 1970, topical management was limited to the passive collection of effluent through rubber tubing. After 1970, the rubber tubing system was adapted to accommodate sump pump-type drainage techniques, which provided an effective means of effluent collection and skin protection. Retrospective case data²⁵ of 50 patients with a fistula found that total parenteral nutrition (TPN) was introduced during this same period, providing a means of meeting the high nutritional demands of persons with a fistula. TPN, in combination with the use of antisecretory agents, effluent management, and an increased understanding of fistula pathology, led to a drastic decrease in mortality rates, similar to those reported today.¹ However, the diagnosis of ECF/EAF remains a concern, because recent mortality rates can range from as low as 8% (as noted in 1 retrospective risk study²² of 135 patients with a fistula) to as high as 20% (as found in a prospective study¹ of 71 patients with a fistula). Retrospective case data²¹ of 277 patients with a fistula found that sepsis is often the primary cause of death.

Not surprisingly, descriptive research²⁶ has found that persons living with a fistula often experience feelings of depression, fear, and anxiety. This emotional and mental distress is most often related to extensive care requirements, perifistula skin irritation, leaking management systems, and pain during dressing changes.^26,27 These factors contribute to the decreased productivity and the social isolation reported by individuals with a fistula.²⁶ The negative financial impacts of long-term fistula management are reportedly severe²⁶ and in comparable patient groups, cross-sectional survey data²⁸ have shown that severe, effluent-related skin breakdown has led to an average loss of 4.56 quality-adjusted life days a month.

Negative pressure wound therapy (NPWT) is a commonly used topical management system in ECF/EAF care.²⁹ A retrospective case series³⁰ of 29 postoperative abdominal surgery patients found that NPWT led to new fistula formation in 6 participants.³⁰ Recent National Institute for Health Care Excellence³¹ (NICE) guidelines indicated that NPWT may be an appropriate alternative therapy in the open abdomen; however, new fistula formation has reportedly occurred at an estimated rate of 7% in patients treated with NPWT. Given the potentially devastating outcome of fistula pathology, this is a particularly concerning complication.

Despite the key role of topical management in fistula care,^10,19 research has been limited to case-based observational designs and clinical recommendations that are largely based on expert opinion.¹⁸ Newly updated ECF/EAF clinical practice guidelines from Nurses Specialized in Wound Ostomy and Continence Canada¹⁸ (NSWOCC) provide clinical direction on various topical management approaches. Due to the lack of peer-reviewed research, recommendations remain largely based on expert opinion and clinical observations. Guideline authors concluded that topical management is one element of a comprehensive ECF/EAF care plan.¹⁸ However, a recent systematic review²⁹ focused solely on NPWT and vacuum-assisted closure (VAC) and their role in the management of adults with ECF concluded that NPWT was a safe and definitive means of achieving spontaneous closure or of facilitating the transition to surgical closure. To address this apparent gap and discrepancy in recommendations, the current authors aimed to gather all available evidence pertaining to all topical management interventions in adult patients with ECFs/EAFs in order to consider the following questions:
1.    What are the topical management interventions used in ECF/EAF care?
2.    What role does topical management play in achieving fistula closure?
3.    What role does topical management play in long-term fistula care?

An electronic literature search of PubMed, the Cumulative Index of Nursing and Allied Health Literature (CINAHL), and Scopus was used to identify articles pertaining to topical management of ECFs and EAFs published in English from January 2004 to January 2019. Database searches were completed independently by 3 review authors using keywords or medical subject heading (MeSH) terms that included enterocutaneous fistula, enteroatmospheric fistula, negative pressure wound therapy, NPWT, vacuum-assisted closure, VAC, pouch or pouching, troughing, bridging, collection device, dressing, and wound care. A librarian assisted in the navigation of the database search system. Studies with both pediatric and adult participants or exclusively adult participants were considered for inclusion; research involving nonhuman subjects, exclusively pediatric participants, single-person case studies, unpublished literature, and exclusively surgical interventions was excluded.

To facilitate review, duplicate articles were excluded, and abstracts were screened for relevance to the research questions. To ensure all relevant articles were identified, one author conducted a manual search of the recently published systematic review²⁹ and ECF/EAF practice guidelines.¹⁸ Articles appropriate for inclusion were reviewed in full text for interventions relating to topical ECF/EAF management strategies. Each article was categorized using The Oxford Centre for Evidence-Based Medicine Levels of Evidence,³² which defines level of evidence as follows: level I — randomized control trials, Level II — individual cohort studies, Level III — case control studies, Level IV— case series, and Level V — expert opinion.

If articles met the inclusion criteria, the Joanna Briggs Institute³³ (JBI) Critical Appraisal Checklist for case series was used to assess for risk of bias and methodological quality. This tool was selected because it has undergone extensive peer review for its ability to assess methodological quality and identify bias in case based studies³³ (see Figure 1). For each publication, the JBI checklist was completed independently by 2 reviewers; a third reviewer was consulted to resolve any disagreements. If a publication did not meet the criteria, it was excluded by mutual agreement of the 2 review authors.

After completion of the JBI checklist, the publications accepted for review underwent data extraction by each author. Outcomes of interest included patient demographics, closure rates, number of fistulas, fistula classification (type of fistula, fistula output, fistula origin), type of topical treatment, adverse events (pain, new fistula formation, fistula recurrence, mortality), follow-up, long term management, perifistula skin protection, effluent management, dressing change frequency, and quality of life. Descriptive statistics were presented; no statistical analysis was completed. A detailed study flow diagram of the search strategy is illustrated in Figure 2.

Study characteristics. Of the 983 articles identified in the literature search, 57 underwent critical appraisal using the JBI checklist for case series. No randomized controlled trials were found among the 15 level IV case-based publications that met the inclusion criteria. Eleven (11) retrospective studies^{11,13-17,34-38} and 1 prospective³⁹ study were included; 3 studies were unclear in their design^9,40,41 (see Table and continued). All studies took place in a hospital setting,^{9,11,13-17,34-41}; 1 study³⁸ included intensive care unit patients exclusively. Studies were conducted in Italy,^13,14 Turkey,^37,40,41 Brazil,³⁶ Argentina,^34,35 Germany,³⁸ the United States,^9,11,13,15 Poland,³⁶ and Australia.¹⁶
Participant characteristics. The 410 participants (179 male, 100 female, gender not provided for 131) ranged from 14 to 89 years of age.^{9,11,13-17,34-41} All participants had an ECF/EAF resulting from a postoperative complication of abdominal surgery.^{9,11,13-17,34-41} Of the 559 fistulas treated in this study, 337 originated in the small bowel, 49 originated in the large bowel, 59 were gastroduodenal, and 121 were of unclear origin.^{9,11,13-17,34-41} The number of fistulas per participant varied from 1 to 8.^{9,11,13-17,34-41}

Eight (8) of the studies classified output as low (<200 mL/24 hours), moderate (200 mL/24 hours to 500 mL/24 hours), or high (>500 mL/24 hours)^{11,15,17,34,36,38,39,41}; 3 studies classified output as low (<200 mL/24 hours) or high (>200 mL/24 hours)^13,14,16; 1 study classified output as low (<500 mL/24 hours) or high (>500 mL/24 hours)³⁷; and 3 were unclear in the reporting of output classification.^9,35,40

In the 4 studies that reported participant recruitment, 94 of the 132 participants were transferred from an outside facility.^16,24,34,36 The remaining 11 studies did not specify the source of participant recruitment.^{9,11,13-15,17,35,37-41}

Study quality. All 15 publications were level IV (case series).^{9,11,13-17,34-41} Using the JBI checklist for case series, the current authors found that each study was at high risk of bias in more than 2 domains (see Table and continued).

Selection^{9,11,13-17,34,36,37,38,40,41} and reporting bias^13,14,16,40 were prevalent; data regarding participant demographics and clinical information were consistently reported.^{9,11,13-17,34-41}

Topical intervention. Various NPWT methods were used as the primary intervention across all studies.^{9,11,13-17,34-41} For organizational purposes, review authors categorized interventions as isolating, intubating, or occluding the fistula (see Table and continued).

Fistula isolation. Fistula isolation was described as diverting the effluent from the perifistula tissue. This was achieved by cutting the NPWT foam to surround the fistula.^{9,36,37,38,41} NPWT was applied at pressures ranging from -75 mm Hg to -125 mm Hg, and the fistula was pouched with an ostomy appliance to manage effluent.^{9,11,36,37,38,40,41} If the fistula output was high, a catheter was inserted into the pouch and low wall suction was applied.^9,11,40 In order to achieve a seal with NPWT, ostomy accessories or commercial fistula isolation adaptors were used.^11,38,40 The isolation technique was used in patients where spontaneous closure was not expected9,36 as a means of managing effluent until surgical intervention11,38 and in the presence of mature mucosa.^36-38

Fistula intubation. Fistula intubation was described as the insertion of a Jackson Pratt (JP) drain16 or Foley catheter^36,39 into the fistula orifice. Negative pressure was applied to the collection tubing using -125 mm Hg¹⁶ and -600 mm Hg.³⁹ In 2 studies, NPWT then was applied around the intubated fistula.^16,36 This technique was used as a means of achieving spontaneous closure16,37and for managing effluent until surgical closure.^16,36

Fistula occlusion. Fistula occlusion was described as the application of NPWT directly over the fistula orifice and surrounding tissue. Settings ranged from -50 mm Hg to -600 mm Hg.^{13-15,17,34-38} This technique was applied to non-mature^37,38 or both mature and non-mature fistulas^14,15,34,35 as a means of managing effluent while awaiting spontaneous closure or surgical closure.

When a fistula reached maturation, 3 reviewed study authors reported changing the intervention from the occlusion to isolation with pouching.^36-38 Some study authors reported changing technique when granulation tissue appeared, switching patients from a vacuum aspiration system (VAS) to a sistema de vacio y compactacion (vacuum and compactions system) (SIVACO) once healthy tissue covered the abdominal viscera.³⁵

Perifistula protection. Products used to protect perifistula tissue included ostomy paste^{9,11,35-38,41} (162), powder⁹ (2), and spray¹⁵ (15), as well as hydrocolloid rings^11,38,40 (15) and sheets⁴⁰ (3). Three (3) studies reported perifistula dermatitis resolution among 104 study participants when an adequately sealed NPWT and collection device system was implemented.^11,13,34

Effluent management. Effluent management was described in all studies^{9,11,13-17,34-41}; 8 studies reported output reduction during fistula occlusion,^{13,15,17,34-38} and 2 reported no increase in output after initiation of therapy.^11,13 Two (2) studies quantitatively measured output reduction throughout the intervention and attributed this reduction to occlusion of the fistula orifice.^34,35 No other measurement of output was reported.

In addition, TPN, somatostatin, and octreotide commonly are used in ECF/EAF care and may contribute to successful closure.^6,21,25 Somatostatin and octreotide were used in 8 studies in this review.^{13,14,36,37,39} The use of any other anti-secretory agents was not reported. TPN was reportedly used in all studies.^{9,11,34-17,34-41}

Dressing change frequency. Dressing change frequency ranged from 2 to 5 days and was reported to be based on the selected products’ ability to maintain NPWT system integrity; as a result, no established frequency could be reported.^{9,11,13-17,34-41} In 5 studies,^9,11,13,40 wound healing information was limited to the narrative reporting of improved granulation tissue and wound contracture. One (1) author⁹ provided wound healing data on 1 study participant, noting a reduction in wound size from 34 cm x 39 cm x 4 cm to 10 cm x 11 cm x 0.25 cm over a 7-week period.

NPWT options. A multitude of NPWT systems were identified in the reviewed literature and included V.A.C. systems (3M + KCI),^{9,11,14-17,36,37,40} Renasys AB (Smith and Nephew),³⁶ VivanoMed Abdominal Kit (Paul Hartmann AG),³⁶ collection and pressure flasks,³⁹ SIVACO (Spanish acronym),^34,35 and VAS (Spanish acronym).³⁵ Pressure settings were equally variable and ranged from -50 mm Hg to -600 mm Hg. A nonadherent mesh often was used between the NPWT foam and ECF/EAF to protect the fistula mucosa^9,37 and wound bed.^{9,11,15,17,36-39,41} Duration of NPWT ranged from 8 to 370 days.^{15-17,34,36,37,39-41} NPWT setting was specified in 4 studies; 1 used both continuous and intermittent settings^,36 and 3 used only the continuous setting.^14,36,41 The remaining 11 did not specify the NPWT setting.^{9,11,13,15-17,34,35,37-40}

Outcomes.
Spontaneous closure. Spontaneous closure was the primary outcome in 12 of the 15 studies (164 patients), and rates ranged from 0% to 100%.^{11,14-17,34-40} The time from diagnosis to spontaneous closure ranged from 9 days to 1 year.^{11,14-17,34,35-40} Mature mucosa was reported as a key barrier to spontaneous closure in 4 studies.^15,35,36,37

Surgical closure. Surgical closure was reported in 11 studies involving a total of 210 patients.^{11,14,16,34-41} The time to surgical closure ranged from 40 days to 6 years.^{11,14,16,34-41}

Long-term management. The 10 participants described in 4 studies who did not achieve closure were reported to have managed the fistula with an ostomy appliance long-term.^11,35,38,41

Adverse events. Pain³⁴ and new fistula formation^9,34,36 were reported as adverse events that occurred during topical management. One (1) study,³⁴ involving 33 participants, included the evaluation of patient pain and the provision of analgesia; complications second to analgesia administration were the primary adverse events in the study. One study¹⁶ (N = 9) reported the use of sedation and intravenous analgesia during dressing changes but the authors did not report pain evaluations. New fistula formation was reported in 4 studies (N = 171) among 12 patients.^9,34,35,36 Fistula recurrence was reported as a complication after spontaneous closure in 1 study involving 3 patients; 1 fistula reoccurred.⁴⁰ One (1) author⁹ reported tissue breakdown and maceration of perifistula skin within 6 hours of stopping NPWT in 2 study participants. No studies measured pain using a standardized tool, quality of life, or patient satisfaction regarding any 1 intervention.

Duration of follow-up. The duration of  follow-up was provided in 7 studies and ranged from 3 to 36 months.^{11,14-16,34,37,40} Two (2) of these studies^16,37 clearly stated whether follow-up included all participants; 1 study¹⁶ followed 9 participants for a median of 20 months to determine spontaneous or surgical closure, and the other only measured the incidence of ventral hernia during follow up.³⁷ No study specified a time to determine closure.^{9,11,13-17,34-41}

Mortality. In this review, no deaths were reported to be directly related to topical management^{9,11,13,17,34-41}; 29 participants died of sepsis,^{13,16,34,38,41} which was the leading cause of mortality. The mortality rate in all included studies ranged from 0% to 44%.^{9,11,13-17, 34-41}

This review found that the focus of ECF/EAF topical management research involved various NPWT methods applied directly to the fistula orifice or surrounding a pouching system.

Twelve (12) studies reported spontaneous closure among 164 patients,^{11,14-17,34-40} with 4 case series identifying fistula maturity as a local determining factor in achieving this outcome.^15,35-37 In 3 studies, authors used the occlusion technique until fistula maturity was established or spontaneous closure occurred.^36-38 In the presence of a mature fistula, the intervention changed to isolation with pouching, which bridged the patient to surgical intervention.^36,37 In addition, this technique was reportedly used to prepare the wound bed for graft application^37,38,41 or transition to long-term management.^11,38,40,41 Interestingly, 4 publications reported applying the occlusive technique to both non-mature and mature ECFs/EAFs^14,34,35,37; serum albumin^14,34,35,37 was used as an outcome measure. The aim of these case series was to seal the fistula under high (up to -600 mm Hg)³⁴ subatmospheric pressure to redirect otherwise lost visceral proteins.^14,34,35,37 Somatostatin, octreotide, and TPN remained an established component of ECF/EAF care and present as confounding variables in all studies.^{9,11,13-17,34-41}

Overall, review authors identified a great deal of variability regarding the application and use of NPWT. This variability, along with the inconsistency in fistula classification and the absence of standardized outcome measurements, suggested a lack of consensus among research clinicians and were significant findings. This review also revealed underreporting of adverse events such as pain and a lack of patient representation in all included studies. The absence of comparative literature to support the safety and efficacy of all interventions also was of concern to the review team. The review team recognized the high risk for publication bias in favor of commercially available products and against non-NPWT management strategies. Despite the review team’s use of a systematic approach and intentions to explore all topical management systems, NPWT was the focus of topical management research. The review team further recognized that there may be other topical management techniques used in ECF/EAF care, but they remain underreported or not published in ECF/EAF research.

To the authors’ knowledge, this is the first systematic review to explore the many types of topical management interventions used in ECF/EAF care. Comparative literature is limited to the recently published systematic review by Misky et al,²⁹ which focused on the role of NPWT in 151 adult ECF patients. Misky et al²⁹ limited their search strategy to a single database (PubMed). In contrast, the current review ensured all available publications were identified through a systematic search of PubMed, CINAHL, and Scopus and a manual search of recently published ECF/EAF clinical practice recommendations. Further, this review team reduced the risk for selection and reporting bias by taking a clear and systematic approach in the selection of included publications and by consistently adhering to the inclusion criteria throughout the review process. As a result, the review team identified several additional publications not reviewed by Misky et al,²⁹ as well as new research published since 2014. Due to the low quality of evidence, underreporting, and high risk for study bias, this review team does not support the conclusion reached by Misky et al²⁹ that NPWT is a safe and definitive tool in achieving spontaneous closure. Additionally, Misky et al²⁹ concluded that NPWT is a definitive tool in bridging patients to surgical closure. Given the low level of evidence and the lack of comparative literature, the review team cannot support the use of NPWT over any other topical management system.

Recently published NSWOCC guidelines provided direction on some of the NPWT systems identified in this review.¹⁸ However, the authors stressed that the choice of NPWT intervention should be based on the clinician’s skill, availability of resources, and evidence of the intervention’s supposed efficacy.¹⁸ Recently published NICE³¹ guidelines reported that NPWT is safe to use in the open abdomen; however, this guidance document did not make recommendations beyond a specific population. Therefore, this recommendation cannot be extended to the varying application techniques identified in this review, and the safety of these interventions is uncertain.

This review appraised all available evidence published from January 2004 to January 2019. Despite the extensive review of available literature, the exclusion of non-English publications, literature published before 2004, and unpublished data are possible limitations of this review. Review authors were challenged by the level of study bias and the low quality of studies while using the JBI checklist and acknowledged that the interpretation of results introduced the risk of selection bias. To reduce this risk, the authors reviewed each other’s JBI checklist results, and in the case of any disagreements, involved a third author for resolution.

Limitations to this review also extend to the quality of evidence in the included studies. First, no randomized control trials were found, and studies were all level IV case-based design and at high risk for bias in 2 or more JBI checklist categories. Second, the review team recognized the high risk for publication bias in topical management research; despite the review team’s use of a systematic approach and intentions to explore all topical management systems, all included publications focused on NPWT. The review team recognized other topical management techniques may be used in ECF/EAF care; however, they remain underreported or not published in ECF/EAF research. Third, the included publications only represented those with postoperative fistula formation, and the results were not representative of the entire fistula population. The exclusion of single-person case studies eliminated most long-term topical fistula management strategies, and as a result this population also was underrepresented in this review. Finally, despite both ECF and EAF being recognized as enteric fistula and the fact that the review team recognized that ECFs and EAFs have unique presentations, topical management research has been shown to be inconsistent when describing these 2 pathologies.^9,13-17 This challenged the review team’s interpretation of the data, limited the separation of ECFs and EAFs into 2 distinct categories,^9,13-17 and led to the review team’s decision to combine both of these pathologies within the review.

The current authors would have benefited from information regarding the patient’s acceptance of any applied intervention. In the absence of these data, the review team cannot provide any practical considerations regarding the general tolerability of any system. Pain, odor control, mobility, and independence have been identified as quality-of-life issues in the ECF/EAF population,^26,27 and these factors should be a priority both when selecting an intervention and when evaluating its effects. In addition to patient-centered outcomes, the availability of resources is a consideration when selecting a topical management system. First, the availability of some of these devices may be limited; for instance, the SIVACO system described by Wainstein et al^34,35 is only available in Spain. Second, some of these interventions require a great deal of technical skill, such as the delicate suturing of a Penrose drain to the fistula orifice,⁴¹ while others only involved the application of perforated NPWT foam.¹⁷ Thus, selection is influenced not only by product availability, but also by the understanding that nursing care as well as surgical technique and skill varies internationally. The review team also acknowledged that the wide range of NPWT pressures (-50 mm Hg to -600 mm Hg) used to achieve any intervention’s desired effect is a practical consideration when selecting any system or in assessing patient tolerability. Given the medical complexity presented in persons with fistulas, any intervention selected in ECF/EAF care will likely require modification to meet the patient’s unique needs. The use of ostomy accessories (eg, pastes, rings, pouches) are tools that can assist with these modifications.

Findings in this review suggested a great deal of opportunity for the advancement of topical management in ECF/EAF research. For ECF/EAF research to move forward, an international common language must be established. This review team feels that this movement begins with collaboration among all clinicians involved in ECF/EAF care. Prospective research designs are a challenge in this patient population, given the relatively rare occurrence of ECFs/EAFs. Uniting research groups on an international level may help overcome this barrier. None of the included studies reported using a standardized outcome reporting tool, such as the Strengthening the Reporting of Observational Studies in Epidemiology checklist,⁴¹ and the review team felt this would be of great benefit to future ECF/EAF research. The use of such tools, as well as the integration of patient-centered outcome measures such as pain and quality of life, will assist clinicians and future researchers in determining the overall benefit of any one intervention. The development of multiple interventions, as identified in this review, represents an ongoing need for improvement in outcomes for patients with ECFs/EAFs. Patients with an ECF/EAF have historically benefited from technological innovations, and this trend will likely continue; therefore, this review team supported such advancement in technology.

A systematic review was conducted to explore all topical management techniques used in the care of the adult ECF/EAF population and to explore the role of these interventions in spontaneous and successful surgical closure and in long-term fistula care. The 15, level IV case-based studies reviewed included 410 patients; all included studies used NPWT as part of their treatment approach, applying it either in isolation or as part of intubation or occlusive technique. Spontaneous closure was the primary outcome reported in 12 of 15 studies and occurred in 164 patients. Adverse events included pain, new fistula formation, and fistula recurrence. Practical implications such as the availability of resources and clinician skill were identified as considerations when selecting a management system. Findings of this review suggested that there is a great deal of opportunity in topical management research. The adult ECF/EAF population would benefit from future research that adopted the use of standardized reporting tools, the integration of patient important outcome measures such as pain and quality of life, and continued technological advancements. At this time, due to a lack of study rigor, the presence of confounding, a high risk of study and publication bias, and a general lack of outcome measurement, the quality of available evidence to guide topical management interventions in ECF/EAF care is low. As such, the authors conclude that NPWT may play a role in fistula closure, but given the low level of evidence (level IV), it cannot be recommended as a definitive means of achieving closure. In addition, other aspects of fistula care, such as nutrition and pharmaceutical interventions, are the mainstay in achieving fistula closure and must be included in a holistic plan of care. The authors recommend the use of guidance documents and involvement of specialized wound clinicians to guide topical management interventions in this fragile patient group.

Ms. Wright is a nurse specialized in wound, ostomy, and continence care, Keewaytinook Okimakanak First Nations Tribal Council, Northwestern Ontario, Canada. Ms. Kearney is a nurse specialized in wound, ostomy, and continence care, Queensway Carleton Hospital, Ottawa, Ontario, Canada. Mr. Zhou is a registered nurse, Sunnybrook Health Sciences Center, Toronto, Ontario, Canada. Dr. Woo is an Associate Professor, Queens University, Kingston, Ontario, Canada. Please address correspondence to: Heather Wright, MClSc, Keewaytinook Okimakanak Health, 69 Alderton Street, Leamington, Ontario Canada; email: wright.he@gmail.com.