Video Capsule Endoscopy Is on Cutting Edge of Minimally
Invasive Procedures
This article originally appeared in Pathways, a magazine
published for physicians and the community by UMass Memorial Medical
Center.
Since video capsule endoscopy (VCE) received FDA approval in 2001, UMass
Memorial has become a major VCE referral center, with the expertise of
Gastroenterologist David Cave, MD, PhD, director of clinical gastroenterology
research at UMass Memorial. Dr. Cave is a pioneer in VCE and played a
significant role in the clinical development of the small bowel and the
esophageal PillCamTM.
"At first, VCE was considered an adjunct to conventional endoscopy," he said
of the pill-sized camera that transmits images as it moves through the digestive
tract. "But now it is regarded as a primary tool for small bowel investigation
because it enables us to see the small intestine in a way that we never could
before."
Prior to VCE, he explains, gastroenterologists could use an endoscope passed
through the mouth to see a few inches into the small bowel, or perform a push
endoscopy and get a few feet farther. At the other end, colonoscopy allowed
visualization of a few inches into the ileum. "But there were 15 feet of the
small intestine that could not be visualized," he said. "Other options, like CT
and barium studies, were very indirect, and operative intervention was a last
resort.
"Now, with VCE, we have a noninvasive, passive device that images the full
length of the small intestine," he added. "The resolution is better than other
imaging technologies - we can see individual villi that are 0.1 millimeter in
diameter - and we can detect lesions that are much smaller than those detected
through other modalities."
The VCE procedure is remarkably simple. After a 12-hour fast, the patient
swallows the 11 mm by 26 mm disposable capsule. It passes naturally through the
digestive tract while transmitting images via radio frequency, at the rate of
two per second, to a data recorder worn on the patient's stomach for
approximately eight hours. The data - more than 55,000 images in total - is then
downloaded to a workstation and processed into a video for the physician's
evaluation. Patients can eat and undertake their usual activities during the
eight-hour test, which is generally performed on an outpatient basis.
The primary indication for VCE is obscure gastrointestinal bleeding. "When
traditional endoscopy and colonoscopy cannot find the source, we turn to VCE,
since a significant number of obscure bleeds originate in the small intestine,"
Dr. Cave noted, pointing out that VCE does not replace traditional endoscopy or
colonoscopy. Other indications include suspected Crohn's disease, and detection
of celiac disease and its complications, rare genetic polyp disorders such as
Peutz-Jeghers Syndrome, and small bowel tumors.
"Crohn's disease can be very easy or very difficult to diagnose," he said.
"In the small subset of Crohn's patients who exhibit vague symptoms and have
nondiagnostic radiology, VCE can play a powerful diagnostic role. And we are now
involved in a promising study on the diagnosis of celiac disease, together with
centers in Milan, Turin and Rome, in which VCE appears to be just as effective
as conventional endoscopy in diagnosing this common allergic condition to
gluten, a wheat product."
The technology also has a role in a subset of patients with recurrent
abdominal pain so severe that they must take narcotics to manage it. "In these
patients, about 15 percent have underlying and undetected organic disease," Dr.
Cave said. "With VCE, we can determine if it is underlying disease that is
causing their pain. It can be a huge economic plus because we have a definitive
answer without the need for further investigation."
As added evidence of VCE's effectiveness as a diagnostic tool in the small
intestine, he cites two recent meta-analyses that revealed a 40-percent
diagnostic yield pre-VCE and a 70-percent yield with the technology.
The contraindications for VCE are few. "Patients unable to swallow used to be
excluded, but now we can place the capsule endoscopically, so this is not as
great an issue," Dr. Cave noted. "Demented patients who cannot collaborate with
the study are generally not good candidates. And it used to be contraindicated
in patients with abdominal pain and small bowel obstruction. Now, however, we
administer the capsule knowing it will be retained at the site of obstruction.
We have surgeons standing by to operate on the underlying problem and remove the
capsule at the same time, turning it around from a contraindication to an
opportunity to identify and correct a problem that was previously undetected.
"If there is one message I want to convey, it is that with VCE, we have a
novel, well-tolerated procedure that should be considered much earlier for
problems such as GI bleeding, iron-deficient anemia, and possible small bowel
tumors," he added. The closer VCE is used to the time of bleeding, the greater
the diagnostic yield.
In addition, the esophageal PillCam was approved for use in 2004 and provides
a simple and effective means of diagnosing the cause of heartburn. The
15-minute, office-based test is painless and does not require a full-day
outpatient visit, as is necessary for an endoscopy procedure with sedation.
"VCE is so effective that it is frequently used," said Dominic Nompleggi, MD,
PhD, chief of the Division of Gastroenterology. Medicare and several major
private insurers reimburse for VCE procedures, mostly for the indication of
obscure gastrointestinal bleeding.
UMass Memorial remains a major referral center in the Northeast, with Dr.
Cave's expertise and reputation. As further indication of the high regard in
which Dr. Cave is held in the video capsule endoscopy world, he was asked to be
a principal investigator for the manufacturer of a second VCE system that aims
to enter the marketplace. "Competing companies do not usually go to the same
person," said Dr. Nompleggi. "But Dr. Cave is so well-respected in this field,
it didn't matter.
"What also sets UMass Memorial apart from other facilities offering VCE is
that we can perform double balloon enteroscopy, which enables us to do
laparoscopic therapy on pathologies found with VCE," he continued. "We are one
of only ten sites in the United States with this type of scope, and the only one
in the Northeast.
"Minimally invasive is the watchword today," he added. "Less-invasive,
advanced modalities that are better-tolerated by patients are certainly the
trend, and UMass Memorial is on the cutting edge of this trend."