Enterocutaneous fistulas: a primer for radiologists with emphasis on CT and MRI

Role of Multidetector Computed Tomography in Diagnosis of Acquired Gastrointestinal Fistulas

Introduction Fistulas are abnormal communication between two epithelialized surfaces. Gastrointestinal fistulas are communication between the gut and another epithelialized surface. Fistulas are classified according to anatomic (internal or external), physiologic (output volume), and etiologic characteristics. In the case of clinical suspicion of a fistula, a multidisciplinary approach helps in diagnosing and management. Multidetector computed tomography (MDCT) has an advantage over other imaging modalities due to its ability to reconstruct high-resolution images in seconds, which limits motion or peristalsis artifacts, and is ideal for patients who are uncooperative or who are seriously ill.

Aim Evaluation of MDCT as an initial tool in the diagnosis and characterization of gastrointestinal fistulas.

Methods During this prospective observational study, MDCT was used to assess patients with clinical suspicion of gastrointestinal fistulas. When necessary, contrast agents were used to identify the enteric fistulous tract. The etiology and characterization of the fistulas were determined. Further, the gastrointestinal fistulas were confirmed via endoscopy, cystoscopy, or surgery.

Results The most common type of gastrointestinal fistula is enterocutaneous fistula (ECF) (39%) and the most common cause of gastrointestinal fistulas is postoperative (47%). ECFs were classified according to their etiology, anatomy, and favorable characteristics (85% favorable) along with complexity (64% complex) to aid in the management process. In addition to pancreaticopleural fistulas (22%), biliary (11%), esophageal (8%), and pelvic fistulas (19%) were also observed. There were 19% of fistulas (esophageal and biliary) that were asymptomatic. Endoscopy confirmed such asymptomatic fistulas that were not convincingly detected on CT.

Conclusion In this study, we concluded that with the appropriate clinical history, MDCT can accurately depict enteric fistulas. In addition to characterizing fistulas, MDCT is equally useful for detecting secondary complications like inflammation, obstruction, or abscesses.

Value of CT sinography and analysis of missed diagnosis and misdiagnosis for abdominal wall sinus

Background

The value of CT (computed tomography) sinography in evaluating abdominal wall sinus tracts is currently unclear. The present study aims to investigate the accuracy of CT sinography in diagnosing the extent of abdominal sinus and analyze the reasons for misdiagnosis.

Materials and methods

64 patients with abdominal sinus tract formation (including fistula) undergoing CT sinography in our hospital from January 2018 to November 2020 were retrospectively analyzed. The CT images were blindly and independently re-assessed by two radiologists with 5- and 18-years work experience, respectively. Whether the sinus tract was confined to the abdominal wall or had invaded the abdominal cavity, and whether there was fistula formation were evaluated. The accuracy of CT sinography in diagnosing sinus invasion in the abdominal cavity and fistula formation was calculated. The agreements of CT sinography-surgical results and inter-observer were assessed using weighted-kappa statistics.

Results

The weighted- Kappa of inter-observer agreement (0.825, P < 0.001) and CT sinography—surgical results (0.828, P < 0.001) were both perfect. The diagnostic accuracy, sensibility, and specificity of sinus tract confined to the abdominal wall were 90.6% (95% CI: 80.7–96.5), 85.7% (95% CI: 67.3–96.0), and 94.4% (95% CI: 81.3–99.3), respectively. The diagnostic accuracy, sensibility, and specificity of fistula formation were 93.8% (95% CI: 84.8–98.3), 89.5% (95% CI: 66.9–98.7), and 95.6% (95% CI: 84.9–99.5), respectively. A total of 4 cases of sinus tract confined to the abdominal wall were misdiagnosed as invading the abdominal cavity, 2 cases of sinus tract invading the abdominal cavity were misdiagnosed as confined to the abdominal wall, 2 cases of enterocutaneous fistula were missed, 1 case of enterocutaneous fistula was misdiagnosed, 1 case of vesico-cutaneous fistula was misdiagnosed, and no cases of vesico-cutaneous fistula were missed.

Conclusions

CT sinography can accurately assess the extent of an abdominal sinus tract and reveal fistula formation, despite some inevitable misdiagnosis and missed diagnosis. Radiologists should find more clues to improve the diagnostic accuracy.

Stable Gastric Pentadecapeptide BPC 157 and Wound Healing

Significance: The antiulcer peptide, stable gastric pentadecapeptide BPC 157 (previously employed in ulcerative colitis and multiple sclerosis trials, no reported toxicity (LD1 not achieved)), is reviewed, focusing on the particular skin wound therapy, incisional/excisional wound, deep burns, diabetic ulcers, and alkali burns, which may be generalized to the other tissues healing.

Recent Advances: BPC 157 has practical applicability (given alone, with the same dose range, and same equipotent routes of application, regardless the injury tested).

Critical Issues: By simultaneously curing cutaneous and other tissue wounds (colocutaneous, gastrocutaneous, esophagocutaneous, duodenocutaneous, vesicovaginal, and rectovaginal) in rats, the potency of BPC 157 is evident. Healing of the wounds is accomplished by resolution of vessel constriction, the primary platelet plug, the fibrin mesh which acts to stabilize the platelet plug, and resolution of the clot. Thereby, BPC 157 is effective in wound healing much like it is effective in counteracting bleeding disorders, produced by amputation, and/or anticoagulants application. Likewise, BPC 157 may prevent and/or attenuate or eliminate, thus, counteract both arterial and venous thrombosis. Then, confronted with obstructed vessels, there is circumvention of the occlusion, which may be the particular action of BPC 157 in ischemia/reperfusion.

Future Directions: BPC 157 rapidly increases various genes expression in rat excision skin wound. This would define the healing in the other tissues, that is, gastrointestinal tract, tendon, ligament, muscle, bone, nerve, spinal cord, cornea (maintained transparency), and blood vessels, seen with BPC 157 therapy.

Fistulas Healing. Stable Gastric Pentadecapeptide BPC 157 Therapy

This review is focused on the healing of fistulas and stable gastric pentadecapeptide BPC 157. Assuming that the healing of the various wounds is essential also for the gastrointestinal fistulas healing, the healing effect on fistulas in rats, consistently noted with the stable gastric pentadecapeptide BPC 157, may raise several interesting possibilities. BPC 157 is originally an anti-ulcer agent, native to and stable in human gastric juice (for more than 24 h). Likely, it is a novel mediator of Robert's cytoprotection maintaining gastrointestinal mucosal integrity. Namely, it is effective in the whole gastrointestinal tract, and heals various wounds (i.e., skin, muscle, tendon, ligament, bone; ulcers in the entire gastrointestinal tract; corneal ulcer); LD1 is not achieved. It is used in ulcerative colitis clinical trials, and now in multiple sclerosis, and addressed in several reviews. Therefore, it is not surprising that BPC 157 has documented consistent healing of the various gastrointestinal fistulas, external (esophagocutaneous, gastrocutaneous, duodenocutaneous, colocutaneous) and internal (colovesical, rectovaginal). Taking fistulas as a pathological connection, this rescue is verified with the beneficial effects in rats with the various gastrointestinal anastomoses, esophagogastric, jejunoileal, colo-colonic, ileoileal, esophagojejunal, esophagoduodenal, and gastrojejunal. This beneficial effect occurs equally when the gastrointestinal anastomoses are impaired with the application of NSAIDs, cysteamine, large bowel resection, as well as concomitant esophageal, gastric, and duodenal lesions and/or ulcerative colitis presentation, short bowel syndrome progression, liver and brain disturbances presentation. Particular aspects of the BPC 157 healing of the fistulas are especially emphasized.

A modern multidisciplinary approach to the treatment of enterocutaneous fistulas in Crohn's disease patients

INTRODUCTION

Enterocutaneous fistulas (ECFs) is a manifestation of penetrating Crohn's disease (CD) that is challenging to treat and has considerable morbidity and mortality rates.

AREAS COVERED

This review aims to explore the practical and updated principles for the optimal treatment of ECFs in CD patients.

EXPERT OPINION

Optimal ECF management requires a multidisciplinary approach. Treatment first includes fluid resuscitation and electrolyte rebalancing with control of sepsis by means of antibiotics and, when indicated, drainage of infected collections. Subsequent therapeutic steps include nutritional support, control of the fistula output and treatment of peristomal skin. Anti-TNF-α therapy seems to have limited utility only after sepsis is resolved and intestinal stenosis excluded. However, ECFs heal in only approximately one-third of cases without surgical intervention. Thus, correct surgical timing combined with adequate nutritional support, sepsis resolution and skin care is considered the appropriate preoperative setting.

[Management of patients with enterocutaneous fistulae]

Enterocutaneous fistula (ECF) is the most serious postoperative life-threating complication of various abdominal surgical interventions. Treatment of patients with ECF is associated with life-threatening complications including sepsis and septic shock, intestinal failure and severe water-electrolyte disorders that causes high mortality rates (35-75% according to national authors and 6-33% according to foreign colleagues). This issue is especially relevant in the cases of enteroatmospheric fistulae and high ECF with loss of intestinal contents of more than 500 ml per day. In the absence of correct conservative therapy, this quickly results progression of sepsis and development of multiple organ failure. Surgery without complex preoperative preparation in this period may be fatal and lead to clinical aggravation and death of patient in early postoperative period. Each patient requires an individual approach. However, there are general principles of treatment too. This literature review describes the main aspects of conservative treatment of patients with enteric fistulae.