Capsule endoscopy (CE)

Capsule endoscopy, also known as wireless capsule endoscopy or video capsule endoscopy, is a gastrointestinal study that uses a pill camera to take images of the intestinal lumen

• capsule is ingested and transmits images at 2 to 6 frames per second over the course of 8 to 12 hours until the battery expires. It generates 512 by 512-pixel, high-resolution images that allow detailed inspection of the gastrointestinal mucosa. A trained gastroenterologist then reviews the images. Battery life can be a limiting factor during capsule endoscopies, and 16.5% of studies are incomplete due to battery expiration
• introduction of capsule endoscopy (CE) in 2000 provided a new non-invasive means of imaging the, previously difficult to access, small bowel
  • a swallowable pill camera acquires images (subsequently converted to a video format on a computer) as peristalsis propagates it through the gastrointestinal (GI) tract. It is now established as the first-line investigation for diseases of the small bowel
  • uptake has been swift in the United Kingdom with 91% of gastroenterologists using CE in a survey in 2010 (2)
• CE is contraindicated in patients with swallowing disorders and known gastro-intestinal obstruction due to the risks of aspiration and retention of the capsule

Indications:

• most common indication is for obscure gastrointestinal bleed thought to be located in the small bowel after upper and lower endoscopic procedures failed to find a bleeding source
  • video capsule has a 35% to 77% detection rate of obscure gastrointestinal bleeds
• other indications for small bowel capsule endoscopy include (1):
  • diagnosis of Crohn's disease and evaluation of Crohn's disease activity,
  • diagnosis of celiac disease,
  • and evaluation of refractory celiac disease,
  • polyposis syndrome surveillance,
  • small intestine tumors such as neuroendocrine tumors,
  • or carcinoid tumors

Contraindications (1):

• individuals with dementia are usually poor candidates
• swallowing disorders may cause difficulty in ingesting the capsule
• relative contraindication in patients with cardiac pacemakers, defibrillators, or left ventricular assist devices due to a concern for possible interference between the capsule and the cardiac devices
• pregnant women should not have capsule endoscopy since there are no studies on the safety of capsule endoscopy in this patient population
• risk of capsule retention is greatest in patients with known or suspected strictures, fistulas, and obstructions
• video capsule can also be retained due to achalasia, esophageal diverticula, esophageal strictures, or pyloric stenosis
• castroparesis may slow the mobilization of the capsule

Capsule retention is reported in up to 2% of procedures and risk factors include prolonged use of non-steroidal anti-inflammatory drugs, previous abdomino-pelvic irradiation and Crohn’s disease (CD) (3)

Reference:

1. Robertson K, Singh R.Capsule Endoscopy.StatPearls [Internet]
2. McAlindon ME, Parker CE, Hendy P, Mosea H, Panter S, Dabvison C, Fraser C, Despott EJ, Sidhu R, Sanders DS, et al. Provision of service and training for small bowel endoscopy in the UK. Frontline Gastroenterol. 2012;2:98-103.
3. Liao Z, Gao R, Xu C, Li ZS. Indications and detection, completion, and retention rates of small-bowel capsule endoscopy: a systematic review. Gastrointest Endosc. 2010;71:280-286.