Preliminary Diagnosis: Abdominal Fistulas

I. What imaging technique is first-line for this diagnosis?

CT with oral and intravenous contrast

II. Describe the advantages and disadvantages of this technique for diagnosis of abdominal fistulas.

Advantages

  • Quick examination after allowing oral contrast to migrate through the bowel

  • Specific examination in identifying a particular place of bowel abnormality and the exact length and location of the fistula. The type of fistula may be ascertained.

    Continue Reading

  • Ability to obtain mutiplanar reformats for further analysis as well as 3D reconstructions

Disadvantage

  • Exposure to ionizing radiation with relative contraindications in pregnant female patients

III. What are the contraindications for the first-line imaging technique?

  • Relative contraindications in pregnant female patients; otherwise, no other significant contraindications exist

IV. What alternative imaging techniques are available?

  • Upper GI fluoroscopy

  • Contrast enema

  • Fistulagram

  • Radiography

  • MRI

V. Describe the advantages and disadvantages of the alternative techniques for diagnosis of abdominal fistulas.

Upper GI fluoroscopy
Advantages

  • Inexpensive

  • Can specifically isolate and identify the fistula tract with barium or water-soluble oral contrast

  • Radiation level is overall low, but varies based on the operator.

Disadvantages

  • Takes a great deal of patient cooperation and maneuverability to conduct the exam successfully.

  • May not be diagnostic, especially if there are contrast-filled loops of bowel overlying the region of abnormality

  • Can take more than 24 hours to opacify distal loops of bowel

Contrast enema
Advantages

  • Inexpensive

  • Can specifically isolate and identify the fistula tract with barium or water-soluble oral contrast

  • Radiation level is overall low but varies based on the operator.

Disadvantages

  • Takes a great deal of patient cooperation and maneuverability to conduct the exam successfully. Often uncomfortable for the patient

  • May not be diagnostic, especially if there are contrast-filled loops of bowel overlying the region of abnormality

  • Frequently messy as there is leakage of contrast on the patient and the fluoroscopic table

Fistulagram
Advantages

  • Inexpensive

  • Can specifically isolate and identify the fistula tract with barium or water-soluble oral contrast

  • Fistula length and other characteristics of the fistula can be obtained.

  • Radiation level is overall low but varies based on the operator.

Disadvantages

  • Takes a great deal of patient cooperation and often maneuverability to conduct the exam successfully

  • Frequently messy as there is leakage of contrast on the table and patient

Radiography
Advantages

  • Inexpensive

  • May show ectopic gas

Disadvantages

  • Very nonspecific and difficult to identify and characterize a fistula

  • Only beneficial if oral contrast had been administered prior to the study.

MRI
Advantages

  • Identifies areas of hyperemic bowel and hyperenhancing granulation tissue around a fistulous tract after administration of contrast

Disadvantages

  • More expensive than obtaining a CT, fluoroscopic evaluation, radiographs

  • Requires patient cooperation during acquisition of the images to minimize artifact

  • Abundance of bowel gas limits resolution when interpreting MR images.

VI. What are the contraindications for the alternative imaging techniques?

Upper GI fluoroscopy

  • Upper GI fluoroscopy has relative contraindications in pregnant female patients. Otherwise, no significant contraindications exist.

Contrast Enema

  • Contrast enema has relative contraindications in pregnant females. Otherwise, no significant contraindications exist

Fistulagram

  • Fistulagram has relative contraindications in pregnant female patients. Otherwise, no significant contraindications exist.

Plain films (radiographs)

  • Plain film (radiographs) has relative contraindications in pregnant female patients. Otherwise, no significant contraindications exist.

MRI

  • No significant contraindications exist. Relative contraindication to administer gadolinium-based contrast agent during pregnancy

Copyright © 2017, 2013 Decision Support in Medicine, LLC. All rights reserved.

No sponsor or advertiser has participated in, approved or paid for the content provided by Decision Support in Medicine LLC. The Licensed Content is the property of and copyrighted by DSM.

Jump to Section