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http://www.ccfa.org/news/wireless_endoscopy.html Wireless Endoscopy: The Camera CapsuleAlan L. Buchman, M.D., M.S.P.H.The Summer 2002 issue of CCFA's magazine, "Foundation Focus," featured a story on diagnostic tests titled "Scopes and Scans." ("Foundation Focus" is sent as a benefit of CCFA membership.) Here are more details about capsule endoscopy, or the "mini camera pill".Many people have heard about a new technique known as wireless endoscopy, approved by the FDA last August. Right out of science fiction -- like "Fantastic Voyage" -- this little capsule can be swallowed and take a video of the small intestine. In this article, we explore some of the myths about the capsule, what it can and cannot do, and why it is helpful in diagnosing Crohn's disease and other illnesses of the small bowel. CCFA would like to thank Dr. Buchman for preparing this article.The Given M2A capsule video endoscope now allows the gastroenterologist to see much of the small intestine as never before visualized. This device was approved by the Food and Drug Administration in August, 2001. The capsule is like a cruise missile, propelled through the intestinal tract by peristalsis, more commonly known as contractions of the intestines. While not quite the jungle cruise, the Given video capsule endoscope does take the gastroenterologist on a fantastic voyage in a far away land not previously well explored.The capsule spends its first 30-60 minutes in the stomach before passing into the duodenum, or first part of the small intestine. With its 240-degree viewing angle, the capsule can allow relatively complete viewing of the small intestine. It also magnifies the actual intestine by some eight times so that villi (tiny appendages lining the intestinal tract) can actually be seen. Along the way, the wireless capsule snaps photographs at a rate of two per second. These 50,000-60,000 images are transmitted via high frequency radio waves to a data recorder worn on a belt. The images are then downloaded to a computer after the capsule's amazing 2-6 hour voyage through the small intestine and are viewed by the gastroenterologist as a video. Currently, we are unable to take biopsies with the capsule, but it is anticipated that improvements to the device may permit that within a few years.Visualizing the small intestine to diagnose Crohn's disease, rare tumors and sources of bleeding has always been a challenge for gastroenterologists. Often, endoscopy and colonoscopy were not revealing the source of the problem. We are studying how well the capsule endoscope compares to the traditional small bowel study (known as a barium X ray or upper GI series with small bowel follow-through) for the diagnosis of Crohn's disease and bleeding of obscure origin. We also use it in patients who have had small intestinal transplantation to determine whether rejection of the transplanted intestine has occurred. We have diagnosed patients with Crohn's disease who had virtually no symptoms of the disease, only microscopic amounts of blood in their stool.Conventional endoscopy into the small intestine, when possible, can visualize only about 20% of the intestine at most. In the 1980s the Sonde endoscope was developed. This procedure required a long tube to be inserted into the intestinal tract over 6-8 hours. The patient lay on a table until x-rays showed the end of the tube to have passed through the small intestine; sometimes it never did. The gastroenterologist could then slowly pull the tube back, observing the intestine during withdrawal. Unfortunately, even under the most optimal conditions, only 50-80% of the intestine could be seen.Barium x-ray studies of the small intestine do not show pictures of the intestine, but offer an outline of the intestine. An ulcer can be identified because an ulcer is similar to an incomplete hole in the mucosa, or lining of the digestive tract; barium fills in the hole. Flat lesions that may cause bleeding, ulcers from Crohn's disease, some strictures or blockages of the intestine, and tumors might be missed with this traditional method.Although the capsule often passes into the colon while the videotaping continues, its battery runs out before the journey through the colon is complete. Passage through the colon is generally much slower than through the small intestine because the contractions in the colon are slower. Therefore, the capsule does not replace traditional colonoscopy for colon cancer screening or other purposes. It takes about 20 minutes to be wired up for the procedure. Several wires are attached to the abdomen like ECG leads. The wires pick up the radio signal from the capsule as it travels through the intestine. The wires are connected to a lightweight data recorded worn on a belt similar to a carpenter's tool belt.The capsule itself measures only 0.4 x 1.0 inches in size. Inside this miniature Voyager are a color camera, four light sources, a radio transmitter, and batteries. The capsule is swallowed along with a small amount of simethicone which helps prevent air bubbles in the small intestine and makes viewing of the video easier for the gastroenterologist. We have found the capsule is better tolerated by patients and they can return to work or shopping while undergoing endoscopy. Strenuous exercise is discouraged to avoid pulling off one of the wires. No eating or drinking is permitted for the first two hours of the study after which liquids can be consumed. A small meal is permitted after four hours. The patient returns to the gastroenterologist after eight hours to have the belt and wires removed. The capsule is excreted naturally in a couple of days and is disposable; most patients never notice it. During conventional endoscopy, air is used to expand the abdominal cavity to better examine the intestines. This does not occur with the video capsule, therefore the patient is less distended and not uncomfortable. The lack of air does not affect the viewing of the video, but does make the results appear a little different to the gastoenterologist than what he or she is normally used to seeing during conventional endoscopy. Unlike conventional endoscopy, the capsule can flip over and the view can be much like CircleVisionTM (used to showcase items for a 3-D circular view on Web sites and other animation applications). It takes about 2 � hours to load the video onto a computer, so the video is generally not seen by the gastroenterologist until the following day. Special software to help the gastroenterologist pinpoint the location of the intestine that is abnormal will soon be available, most likely in early 2002. Currently, it may be difficult for the gastroenterologist to determine the exact location of an abnormality.There is a small risk the capsule could become lodged in the intestine. Although the capsule is quite small, it should be used with caution in patients who have had major abdominal surgery. The capsule should not be used in patients with symptoms of a bowel obstruction, including nausea and vomiting and abdominal distention unless the patients clearly understand the capsule could cause a complete bowel obstruction that may require hospitalization, and possibly surgery.If you think you may benefit from undergoing testing with the video capsule endoscope, you should first speak with your doctor to determine if this test would be helpful for you and help change the way you are treated. For more information on studies with the capsule endoscope in patients with Crohn's disease see www.ibdcenter.net and givenimaging.com.ALAN L. BUCHMAN, M.D., M.S.P.H.Northwestern University Medical SchoolDivision of Gastroenterology and HepatologyInflammatory Bowel Disease CenterChicago, IL
 
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