Wireless Capsule Endoscopy

What Is Wireless Capsule Endoscopy?

Wireless video endoscopy or video capsule endoscopy (VCE) is a novel noninvasive technology designed primarily to provide diagnostic imaging of the small intestine, an anatomic site that is proved very difficult to visualize. Limited views of the esophagus, stomach, and cecum may be acquired. However, it's main objective is to look at the small intestine. Images are of excellent resolution and have a 8:1 magnification, which is higher than that of conventional endoscopes.

 

Indication of VCE

  • These indications have been approved by the United States FDA since August of 2000.
  • Detection of the source of obscure (microscopic) gastrointestinal bleeding after conventional work up (small bowel endoscopy, colonoscopy, small bowel series) have been completed or have not revealed a source.
  • The diagnosis of abdominal pain in the setting of partial obstructive symptoms.
  • Assessment of the extent of Crohn’s disease in the small bowel.
  • Helping to define the extent of malabsorptive conditions, such as celiac disease, and the detection of small bowel tumors, helping the surveillance of small bowel polyps and premalignant disorders such as Gardner’s syndrome, and assisting the evaluation of chronic diarrhea.
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    It is important to note that the current design of the capsule does not make it easy to visualize colonic lesions, although, occasional abnormalities may be visualized in the cecum.

     

    Procedure

    Patients are asked to fast over night and an eight-lead sensor array is fastened to the abdomen in a correct position which helps determine the location of the capsule at all times. The array is connected to a solid-state recorder and a power pack is worn on a belt. The 11 x 26 mm video capsule is swallowed with water and clear fluids can be taken in two hours and food and medication can be taken four after ingestion. The capsule takes two images per second which are transmitted as JPEG files to the recorder. The recorder acquires up to 50,000 images over approximately seven hours. The belt is removed after seven hours and the recorded images are downloaded to a work station. Subsequently image management software creates a video that can be viewed. The view of the video, selection of represented images, and generation of a report can take 30 to 90 minutes.

     

    This procedure can be performed as an outpatient procedure and patients need not stay at the facility. However, they should return after seven hours for removal of the recorder and belt.

     

    Risks

    The capsule may be retained in patients with strictures which may not have been apparent even with enteroclysis. The capsule does not appear to cause obstruction but tumbles around the narrowed segment. It may need to be removed surgically in such patients. The development of pain usually heralds passage through a tight stricture. The risks of surgical intervention for capsule recovery is less than one percent; the risk is offset by virtue of the fact that the stenosis would be treated during retrieval of the capsule.

     

    Limitations

    The main limitation of VCE is that it does not permit tissue sampling or therapeutic intervention. Longitudinal location of a lesion is done by educated guess of known landmarks. No data is available of the reproducibility of the findings. The procedure may be contraindicated in patients with the following conditions:

     

    Dementia

    Delayed gastric emptying or gastroparesis.

    Esophageal stricture or swallowing disorder that could prevent passage of the capsule.

    Small bowel obstruction (unless a surgeon is involved and the patient has been cleared for surgery).

    Patients who are inoperable or refuse surgery.

     

    The other major limitation of VCE is payment. Medicare has approved a CPT code that will pay, however, in Louisiana this has not been approved by Medicare at this time. Private insurance carriers are paying on a case-by-case basis. You need to check with your insurance company first.