Video capsule endoscopy for the investigation of the small bowel: primary care diagnostic technology update.

ADVANTAGES OVER EXISTING TECHNOLOGY Video capsule endoscopy (VCE) was first developed in 1999 and has been in widespread use since the late 2000s. It is primarily used for investigation of the small bowel and has the advantage of being able to accurately examine the small bowel which cannot be easily reached by standard endoscopy methods. The major advantages are that it is non-invasive, safe, and convenient for the patient, and involves no ionising radiation. Additionally, VCE can provide some information on the rest of the gastrointestinal (GI) tract as well as basic information on small bowel transit time. Previously the small bowel could only be imaged by contrast small bowel studies (for example, barium/gastrograffin) and more recently by cross-sectional imaging such as computed tomography (CT) and Magnetic resonance imaging (MRI). CT and contrast small bowel meal are relatively insensitive for examining the small bowel. Small bowel ultrasound, CT enterography/enterocolysis and MRI enterography/enterocolysis are readily available and can be performed to visualise the small bowel, but requires a radiologist with specialist experience for interpretation of the results. CT has the limitation of exposure to ionising radiation. Available examinations to investigate the small bowel mucosa are by anterograde, that is, per oral push enteroscopy, single/ double balloon enteroscopy, and retrograde, that is, per rectum ileoscopy, however, these are not widely available, invasive, and are technically challenging. However, these investigations do allow therapy such as the treatment of angiodysplasia and small lesion removal where necessary. They are generally reserved for cases where noninvasive investigation has confirmed an abnormality. Disadvantages of VCE are that therapeutic work cannot be performed and biopsies cannot be obtained. New developments in VCE have led to new capsules which can be used to examine the oesophagus and colon. They may be used for patients who do not tolerate upper/ and/or lower gastrointestinal endoscopy. Also, reader software used for analysis has improved and newer capsules have increased battery lives with excellent lens resolution thus providing high definition images.