enteroclysis

Fixierte
Stenose des Dünndarms bei Morbus Crohn. Enteroklysma im Doppelkontrast.
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Fixierte
Stenose des Dünndarms bei Morbus Crohn. Enteroklysma im Doppelkontrast.
Wikipedia • CC BY-SA 3.0
Radiopaedia • CC-by-nc-sa 3.0 • de

Enteroclysis is a gastrointestinal technique designed to provide improved evaluation of the small bowel. The conventional fluoroscopic technique is not widely used since it is somewhat invasive, time and labor intensive, and not particularly pleasant for the patient. The exam also requires a degree of skill to perform, and often the information can be gathered through other techniques. In experienced hands, however, it is the best radiographic technique for evaluation of the small bowel mucosa.

Modifications of the traditional technique may involve CT or MRI (see CT enteroclysis and MR enteroclysis). These should be differentiated from the more routine CT and MR enterography.

Indications

  • examination of mucosal detail of the small intestine
  • improved evaluation of small bowel tumors or inflammatory disease relative to small bowel follow through (SBFT)

Procedure

Enteroclysis can be performed in one of three main ways:

  • single-contrast enteroclysis
    • easier technique and less patient discomfort, but evaluation of the mucosa is less than with the other techniques
  • air-contrast enteroclysis
    • better for evaluation of mucosal detail of proximal small bowel loops
    • may be better for long segment disease
    • more discomfort for the patient than single contrast
  • methylcellulose enteroclysis
    • better for evaluation of mucosal detail than single-contrast
    • may be better for short segment disease
    • easier to visualize through bowel loops
    • some consider it a more consistent double-contrast exam than air-contrast enterocylsis
    • more discomfort for the patient than single contrast
Equipment
  • an 8-13 F enteroclysis catheter
    • topical anesthetic to ease passage of the enteric tube
  • multiple syringes or an enteroclysis pump
  • barium specially prepared for the type of study
    • single-contrast enteroclysis: low density barium (20-40% weight/volume)
    • air-contrast enteroclysis: medium density barium (40-80% weight/volume)
    • methylcellulose enteroclysis: high density barium (80% weight/volume)
    • enteroclysis is rarely if ever performed in a setting of possible small bowel leak, but if situation were to arise, water-soluble contrast should be used
  • compression paddle
General technique

There are multiple different techniques that have evolved for performing enteroclysis. The following technique is one conventional approach. In some centers the patient undergoes a clear liquid diet or full bowel prep the day before the exam to clear the terminal ileum and ascending colon. Medication agents that inhibit small bowel peristalsis should be temporarily suspended on the day of the exam (e.g. narcotics).

  • Patient does not eat after midnight.
  • Some centers administer metoclopramide (Reglan) immediately before the exam to aid in intubation and speed small bowel motility. This is contraindicated in patients with paraganglioma or patients with some neurologic conditions.
  • Some centers administer anxiolysis and anesthesia for conscious sedation (e.g. fentanyl and midazolam).
  • An enteric tube (e.g. a nasoduodenal tube) is advanced beyond the pylorus
  • If a single-contrast or double contrast enteroclysis is to be performed, the tip may rest in the second portion of the duodenum.
  • If methycellulose is to be used, the tip should be in the proximal jejunum.
  • After proper positioning of the tip, barium is instilled through the catheter with syringes or a pump.
  • The optimal flow rate depends on the patient's specifics, but may be around 50-150 mL/min
    • Single-contrast enteroclysis
  • A volume of 600-1200 mL of contrast is suggested at an initial rate of 75 mL/min .
  • Manual compression with a paddle will likely be necessary to spread out bowel loops for optimal visualization.
  • Water may be used to flush the barium.
    • Air-contrast enteroclysis
  • A volume of 300-600 mL of contrast is suggested.
  • Room air or CO2 is introduced via a pump when the barium column reaches the distal small bowel. This can be quite uncomfortable for the patient and should be done carefully and likely with sedation.
    • Methylcellulose enteroclysis
  • Enteric contrast coats the bowel wall and methylcellulose distends the small bowel.
  • There are multiple different techniques. One source recommends 220-300 mL of barium infused at 60-80 mL through a syringe until half of the expected intestinal loops are visualized.
  • Methylcellulose is instilled through an electric pump
  • Methylcellulose may induce vomiting if it refluxes into the stomach. It will also cause urgency and profuse diarrhea when it reaches the colon, and an enema tip in the rectum may be helpful.

    • History and etymology

    Enteroclysis has been performed since the 1920s . The term derives from "entero-" (intestine) and "klysis" (a washing out).

    Siehe auch:
    und weiter:
    Assoziationen und Differentialdiagnosen zu Enteroklysma:
    MR Sellink
     
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