Small Bowel Video Capsule Endoscopy

Patency Capsule

In order to avoid the problem of capsule retention, a thorough past medical and surgical history should be undertaken. In addition, several other steps have been proposed, including performing investigations such as barium follow-through. In cases where it is suspected that there is a high risk of retention, the patient is given a patency capsule a few days before the VCE procedure. The patency capsule is usually the same size as the video capsule and is made of cellophane. The size of the patency capsule is similar to the size of PillCam and EndoCapsule (26 × 11 mm), while the size of the MiroCam is 24 × 11 mm, which is smaller than the patency capsule, and size of OMOM capsule is 13 × 27.9 mm, which is larger than the patency capsule.

The capsule contains a mixture of barium and lactose, which allows visualization by x-ray. Besides the barium, there is a radiotag inside the capsule, which measures roughly 10 × 2 mm; this allows it to be detected by radio-scanner externally. On either side of the capsule there are wax plugs, in which there are a few holes that allow intestinal fluid to enter and dissolve the content, thereby dividing the capsule into small particles. The time taken to dissolve the capsule varies from 30 to 72 h.^[34]

Difficulty in Swallowing

Another complication of the VCE procedure occurs when patients cannot take the capsule due to difficulty in swallowing, or when a patient is on a mechanical ventilator or has suffered a serious trauma to the face that affects the mouth and the ability to eat and swallow.^[5] In these cases, the capsule can be introduced into the stomach via conventional upper endoscopy.

In patients with swallowing disorders, and especially the elderly, they may cough and expel the capsule directly after ingesting it or the capsule may go to the respiratory tract rather than digestive tract. VCE failure is more common in patients above the age of 80 years, and in the majority of these patients, the failure may be related to prolonged (gastro)esophageal transit time.^[28]

Box 1. Indications and contraindications of video capsule endoscopy.
Indication for small bowel video capsule endoscopy: Obscure gastrointestinal bleeding Crohn's disease Celiac disease Small bowel tumor NSAID enteropathy Screening for polyps Contraindications for video capsule endoscopy: Patients with pacemaker High risk of intestinal obstruction Swallowing difficulties Pregnancy Intestinal pseudo-obstruction Extensive intestinal diverticulosis