Mayo Clinic Study Shows People With Heart Devices Can 'Digest' Advanced
Diagnostic Technology Safely
Capsule endoscopy risk appears minimal in largest study to date
SCOTTSDALE, Ariz., Oct. 26 /PRNewswire-USNewswire/ -- A new Mayo Clinic study
suggests that video capsule endoscopy (CE)
(http://www.mayoclinic.com/health/capsule-endoscopy/MY00139), a procedure that
uses wireless technology in diagnosing intestinal disease, is safe for
patients with heart devices. Wireless electrical gadgets, such as cell phones,
have been shown to interfere with implanted heart devices, including
pacemakers and defibrillators. This risk has led medical experts to speculate
that capsule endoscopy could similarly cause heart devices to fail.
(Logo: http://www.newscom.com/cgi-bin/prnh/20090105/MAYOLOGO)
As a result, the noninvasive procedure has been contraindicated by the /U.S.
Food and Drug Administration (FDA) (http://www.fda.gov) for patients with
cardiac devices. Contraindication means an increased risk may be involved.
Generally, the topic has remained in the subject of speculation, although
several small studies have found no interference with cardiac devices, and no
clinical reports have surfaced linking CE to problems with them.
The study concludes that performing a video capsule endoscopy on patients who
have cardiac devices appears safe, and, conversely, the cardiac implants don't
impair capsule endoscopies.
"Ours is the largest study of its kind, with 84 patients (91 capsule studies),
and we found no complications from the capsule endoscopy," says Jonathan
Leighton, M.D. (http://www.mayoclinic.org/bio/11485957.html), chair of the
Division of Gastroenterology at Mayo Clinic in Arizona and senior author of a
report on the research.
"The size of the study population should give physicians confidence to use the
procedure," says Dr. Leighton. Mayo physicians perform capsule endoscopy
routinely, averaging from two to five cases a week at the Arizona site.
In the study, Lucinda Harris, M.D.
(http://www.mayoclinic.org/bio/14395568.html), and Stephanie Hansel, M.D.
(http://www.mayoclinic.org/bio/12505820.html), reviewed the medical records of
84 patients who underwent CE and had implantable cardiac devices -- cardiac
pacemakers (http://www.mayoclinic.com/health/pacemaker/MY00276),
defibrillators
(http://www.mayoclinic.com/health/implantable-cardioverter-defibrillator/MY00336)
or left ventricular assist devices -- at Mayo Clinic's campuses in Arizona and
Rochester, Minn.
The patients' average age was 73, and 69 percent had pacemakers. In a large
majority of cases (74 percent), the reason for performing the CE was to locate
gastrointestinal bleeding. In each case, the capsule explored the entire
length of the small bowel. Assessments after the procedure revealed no
interference with the implanted cardiac devices.
Approved by the FDA in 2000, capsule endoscopy uses a tiny wireless camera to
examine the inside of the digestive tract. The patient swallows a
vitamin-sized capsule containing a battery-driven camera that travels through
the intestines, taking thousands of pictures. It then transmits them to an
external receiver from areas deep inside the small bowel previously accessible
only through surgery. The device is later excreted through the colon.
The use of capsule endoscopy has solved a long-term problem for doctors:
visualizing the midsection of the small intestine, which can measure 20 feet
in length. Standard endoscopy, done through the mouth or the rectum, can't
penetrate deeply enough and requires anesthesia. Now, CE is used to visualize
the entire small intestine. Most commonly, it is used to find the source of
unexplained bleeding. The procedure is also used to detect the causes of
anemia, abdominal pain and certain intestinal diseases.
Because cell phones, microwave ovens and other wireless appliances have
affected heart devices, physicians were concerned that the radiofrequencies
used in CE may potentially interfere with the radiofrequency of heart devices.
But in the study, the only research complication occurred when a capsule's
receiver stopped working for reasons unrelated to a heart device, according to
Dr. Harris, a Mayo gastroenterologist and first author on this study.
"There were no problems with the devices interacting," says Dr. Harris. "The
data is now out there. We are coming to the point where we know this is a
relatively safe procedure. She was scheduled to report on the project Monday,
Oct. 26, at a meeting of the American College of Gastroenterology
(http://www.gi.org/) in San Diego.
Affirming the procedure's safety when heart devices are present mainly
benefits elderly patients, who are the most prone to have implanted devices
(primarily pacemakers) and to experience unexplained intestinal bleeding from
illnesses or blood-thinning medications
(http://www.mayoclinic.com/health/blood-thinners/AN01304).
Mayo doctors plan to continue using capsule technology on patients with
implants. But even with the positive results of the study, they will continue
to do CE as an inpatient procedure.
"If it were not contraindicated by the FDA, we would do it as outpatient, and
it would reduce costs, just as safely," says Dr. Leighton.
About Mayo Clinic
Mayo Clinic is the first and largest integrated, not-for-profit group practice
in the world. Doctors from every medical specialty work together to care for
patients, joined by common systems and a philosophy of "the needs of the
patient come first." More than 3,300 physicians, scientists and researchers
and 46,000 allied health staff work at Mayo Clinic, which has sites in
Rochester, Minn., Jacksonville, Fla., and Scottsdale/Phoenix, Ariz.
Collectively, the three locations treat more than half a million people each
year. To obtain the latest news releases from Mayo Clinic, go to
www.mayoclinic.org/news. For information about research and education, visit
www.mayo.edu. MayoClinic.com (www.mayoclinic.com) is available as a resource
for your health stories.
SOURCE Mayo Clinic
Lynn Closway, Mayo Clinic Public Affairs, +1-480-301-4337 (days),
+1-480-595-6273 (evenings)
