CE is an easy procedure in comparison to EGD and colonoscopy. It does not require sedation or anesthesia. Furthermore, unlike EGD and colonoscopies, in CE, there is no need for the air insufflations.
The patient can take the capsule after an overnight fast – usually 8–10 h before the small bowel examination – in order to provide a clean field for the capsule. Prior to the procedure, sensors and recorders should be ready. Usually eight sensors are attached to the abdominal wall in different positions to receive good quality images. Sensors may also be within a belt that carries the recorder; this is called the sensor belt. In case of examination of the small intestine, patients can drink water after 2 h and take a small meal after 4 h. The patient is usually discharged home after taking a capsule and asked to return later.
Mechanism of the Procedure
The video capsule starts taking photographs when it is taken out from its box and the patient ingests it with a cup of water. The capsule usually leaves the stomach within 30 min; however, gastric transit time is different from one person to another, depending on the patient's physiology, and it will be affected, for example, in diabetic patients who may suffer from gastroparesis. Duration of the recording depends on the type of the capsule that is used; usually around 8 h in older models, but newer models continue to improve features such as battery life. The images are transmitted through the sensors to the digital recorders, which feed the data to a computer, where they are interpreted using special software, such as the Rapid Reader. The time for reading the data usually takes around 40–60 min, depending on the experience of the endoscopist.[2,3]
The scope of video CE can be affected by the presence of undigested or dark particles of food. This can interfere with the visibility of the mucosa and may lead to missing an abnormality. Colon preparation before the VCE procedure may be needed, and the most frequently used one is a low-volume (2 l) polyethylene glycol (PEG)-based solution. Some studies have shown that colonic preparation will affect the quality of the procedure, but that it does not affect the diagnostic outcome. A meta-analysis of eight randomized controlled trials comparing fasting alone with the use of laxative bowel preparation, using either PEG- or sodium phosphate-based regimens, showed that use of any form of bowel preparation yielded significantly better diagnostic yield and visibility than fasting alone. The impact of prokinetics, which are increasingly being used to facilitate the process, was not considered in the analysis; data for alternative devices have not been analyzed and the results of the meta-analysis may only be relevant to the most commonly used video capsules. For these capsules, lower volume PEG appears to be as efficacious as the higher volumes traditionally used for colonoscopy preparation.
Expert Rev Gastroenterol Hepatol. 2013;7(4):323-329. © 2013 Expert Reviews Ltd.