Video capsule gives views that endoscopy can’t
Diagnosis of small bowel lesions enhanced
The crew of the miniaturized submarine, Proteus, faced dire threats such as monstrous white blood cells and intruder-eating antibodies as they traveled into Professor Benes’ brain to destroy a life-threatening blood clot in the 1966 novel, Fantastic Voyage.
While miniaturization that enables physicians to see inside a person’s body existed only in the imagination of authors in 1966, it is a reality in 2002. A capsule no larger than a vitamin tablet, which contains a camera, light source, battery, and radio transmitter, now enables gastroenterologists to see the entire small intestine and diagnose previously unseen intestinal disorders. Manufactured by Given Imaging in Yoqneam, Israel, the M2A video capsule was approved last year by the Food and Drug Administration (FDA) for marketing in the United States.
"Traditional endoscopy enables us to see 2-3 feet into the small intestine, but that leaves about 15 feet that remains unexplored," says David R. Cave, MD, PhD, chief of gastroenterology at St. Elizabeth Medical Center in Brighton, MA. "The video capsule gives us a nonsurgical option to look for the cause of obscure gastrointestinal bleeding when traditional diagnostic tests don’t show anything."
Patients come into the same-day surgery facility early in the morning to get "hooked up," take the pill, and leave, says Kenneth F. Binmoeller, MD, director of interventional endoscopy services at California Pacific Medical Center in San Francisco. "They can go about their regular day, and they can eat two hours after the video capsule is swallowed," Binmoeller says. Patient preparation is similar to preparation for a regular endoscopy or upper GI exam, with the patient coming in NPO prior to the hookup, he says. The hookup involves wearing a data recorder on a belt and small antenna-like aerials, similar to electrocardiogram leads that are placed on the patient’s body to transmit the signals from the video capsule’s radio transmitter to the data recorder.
"The video capsule’s camera takes two images per second as it travels through the gastrointestinal system, transmits the image to the aerials, which then send the image to the data recorder," Binmoeller explains. When the patient returns later in the afternoon, the aerials are removed and the information from the data recorder is downloaded to a computer. The patient excretes the pill eight to 72 hours after being swallowed, he adds.
While the software can be loaded on any computer, Binmoeller’s center maintains a computer that is dedicated to this one purpose. "We want to reduce any risk of picking up viruses or other problems that could distort the data," he explains.
Cost for the computer workstation is $20,000 for hardware, including a data recorder, and software, and each disposable video capsule is $450.1
There is no additional staff expense, Binmoeller says. Because patients come into the same-day surgery area early, recovery room nurses handle the hookup since they don’t have patients in the area, he says. Patients return late in the day when other staff members are available to unhook the aerials and the data recorder, he adds. Although the hookup is simple and can be done by any staff member, Binmoeller prefers that a nurse handle it in order to answer patient’s questions about the procedure and how it works. "The images should be read by a gastroenterologist," he adds.
Credentialing for physicians has not yet been addressed, Cave says. "It is most reasonable to expect a gastroenterologist to prescribe the video capsule and read the results because a gastroenterologist who regularly performs endoscopy is the person most familiar with the anatomy of the small intestine," he adds.
The procedure generally is not reimbursed by managed care, but companies are reviewing the procedure on a case-by-case basis, Binmoeller says. Although the video capsule gives gastroenterologists a look at previously unseen areas without the need for surgery, it will not replace traditional endoscopy, he says. "The capsule travels too fast through the esophagus to give us a good look, and it only gets pictures of small areas of the stomach because of the size and shape of the organ," he says. "We also don’t get pictures of the large intestine because the battery doesn’t last long enough." Another disadvantage is that there is no way to control the direction of the capsule, so a physician can’t go back, turn the capsule, and look more closely at a certain area, Binmoeller adds.
New technology that does enable the surgeon to "drive" the capsule as it travels through the gastrointestinal tract is in the testing phase, he adds. With the use of a joystick-like device, the surgeon will be able to turn the capsule toward certain areas and in a particular direction, he explains. This will increase the diagnostic capabilities because it will give the surgeon a chance to focus on areas of concern, he adds.
Even with the future capability of "driving" the video capsule, this technology will not give the surgeon the capability to perform any type of biopsy or treatment, Binmoeller points out.
While the video capsule doesn’t allow interventional treatment at the time of the study, it does identify the area that needs to be targeted during surgery or follow-up endoscopy, Cave says. "In 60% of my patients who underwent studies with the video capsule, we were able to clearly define the areas of concern," he says.
Overall, Binmoeller and Cave are enthusiastic about the possibilities the video capsule represent. "If used appropriately," Binmoeller says, "in conjunction with traditional diagnostic methods, it provides a painless, anesthesia-free diagnostic test that can be used for patients with hard-to-diagnose symptoms."
Reference
1. FDA OKs swallowed camera-pill that looks for bowel problems. MSN Health, Nov. 14, 2001. Web: content.health. msn.com/content/article/1728.85347.
Sources
For more information about the clinical aspects of the M2A video capsule, contact:
• Kenneth F. Binmoeller, MD, Director of Interventional Endoscopy Service, California Pacific Medical Center, 2340 Clay St., Second Floor, San Francisco, CA 94115. E-mail: [email protected].
• David R. Cave, MD, PhD, Chief of Gastroenterology, St. Elizabeth Medical Center, 736 Cambridge St., Brighton, MA 02135. Telephone: (617) 782-5218. E-mail: [email protected].
For information about ordering equipment and the video capsule, contact: Given Imaging, Oakbrook Technology Center, 5555 Oakbrook Parkway, No. 355, Norcross, GA 30093. Telephone: (770) 662-0870. Fax: (770) 662-0510. Web: www.givenimaging.com.
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