The first attempt to perform a non-invasive endoscopic examination of the gastrointestinal (GI) tract dates back a few decades. In 1999 UK, doctor Swain was the first human being to ingest the prototype. After much deliberations and research, the capsule finally entered the open market in 2001.
Since then, Capsule endoscopy (CE) has had a tremendous impact on clinical practice by offering a minimally-invasive, and hence well tolerated, alternative to conventional endoscopy. It was initially used for visualization of only the small bowel, but later on, the entire GI tract could be visualized.
CE devices (used for capsule endoscopy) have a shape similar to that of a large vitamin or an antibiotic pill, and their volume is roughly 2 cm3. The standard capsule contains a CCD camera, a lent with bulb-shape, a battery and a transmitter. The camera takes thousands of pictures of the digestive tract during its journey and transmits them for about 8-12 hours to an external recorder, to store the images through some receiving electrodes worn in a jacket or belt on the waist.
This external recording equipment is generally clearly visible and has been perceived as a limitation for the patients, as they need to remain home and usually tend to avoid public transportation. However, the benefits outweigh such limitations.
At the end of the recording, the images are transferred from the recorder to a computer, which converts them into a video that eventually gets evaluated by the doctor. The capsule is then passed out of the body with stool and can be flushed away.
Nowadays, there are five leading companies in the market of CE with continuous evolution of software and technology and prolonged recording time, namely Medtronic, Intromedic, Olympus Corporation, Omom and more recently Capsovision.
The continuous technologic progress has allowed the availability of capsule with double lenses, 2, 4 and 360 degree cameras with progressive increase of the accuracy to detect intestinal lesions. The most common indications for the actual use of the capsule are GI bleeding due to vascular lesions, detection of neoplasms, detection of inflammation due to immune mediated disease, infections or iatrogenic.
At Fakeeh University Hospital, we have recently used Capsule Capsovision for one of our patients, which is the only model that may completely avoid the use of an external recorder. In spite of a transmitter, this capsule has an inside memory and the data remains stored forever. After passing out, the capsule can be retrieved easily with the use of a specific magnetic device provided. The capsule can then be brought back to the hospital for the analysis. The entire process – patient swallowing the capsule and retrieval the following day – is an efficient and easy process. This is the only capsule currently that provides a complete 360 degree recording camera.
The field is under continuous evolution with a number of other prototypes under study, like the spheric capsule, magnetically-actuated soft capsule for fine-needle aspiration biopsy, hybrid magnetic motion, capsule using infrared fluorescence, capsule for targeted medical delivery, capsule with blue light therapy for Helicobacter, capsule with different tools for robotic motion, and lastly an application of new software based on artificial intelligence methodology for lesion recognition.
More recently, CheckCap has developed the C-Scan Cap, which is an ingestible battery-free X-ray-based imaging capsule that consists of an X-ray source and detects ultra-low-dose radiation. The accuracy of the investigation is still under validation though.
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