Given Imaging Ltd., an Israeli diagnostics company, rose to the challenge by developing the first ingestible endoscope. Given's M2A Capsule provides direct visualization of the entire small intestine, a section of anatomy that was previously visible only by surgery. The Food and Drug Administration (FDA) cleared the device for use as an adjunctive tool in August 2001.
The capsule endoscope is part of the Given Diagnostic System and has been considered revolutionary for locating sources of unexplained bleeding. More than 19 million people in the United States suffer from disorders and diseases of the small intestine. GI diseases are the leading cause for hospitalization of people.
Scoping Out New Frontiers
The M2A, weighing 4 grams, contains a miniature video camera, light source, battery and a transmitter. It is made of a specially sealed biocompatible material that is resistant to the digestive fluids in the GI tract. The camera, which is capable of viewing objects as small as 0.1 mm, uses a complementary metal oxide semiconductor (CMOS) chip.
"[CMOS] allows us to have a low-cost imager, which also requires low energy," says Mark Gilreath, president of Given Imaging, Inc., the subsidiary responsible for the Americas. "Those are the two parameters that make CMOS so successful." In a normal 8-hour procedure, the capsule generates more than 50,000 images, at a rate of two frames per second. The single-use device is propelled by peristalsis through the GI tract and is naturally excreted.
The capsule is contraindicated for use with patients with known or suspected GI obstruction, strictures, or fistulas. It is also contraindicated in patients with cardiac pacemakers or other implanted devices. The use of the capsule in pediatric population is currently under evaluation in clinical trials.
"Patients have found the capsule very easy to swallow. And, it is much better tolerated than traditional endoscopy," says Gilreath. "One of the difficulties in swallowing even an aspirin is typically because of the friction. Sometimes aspirin is rough, but this is very smooth. It is made of a very slick material."
Swallowable Procedures
The only prep-procedure is a fast for eight to 10 hours prior to the scheduled examination. The test is conducted while the patient continues normal daily activities.
Gilreath adds that the procedure doesn't require additional training. Many professional societies have concluded that if a doctor has had endoscopy training, the doctor would be trained for this as well, he says. With regards to nurses and technicians, they often assist by giving the capsule to the patient, downloading data, and overseeing the return of the equipment.
Illuminating Results
The first U.S. clinical trial submitted to the FDA, compared capsule endoscopy to push enteroscopy in 21 patients with obscure GI bleeding.1 After the capsule endoscopy procedure was complete, the patient underwent push enteroscopy. The yield of push enteroscopy in the evaluation was 30 percent versus 55 percent for capsule endoscopy. The results showed that capsule endoscopy identified small intestinal bleeding sites beyond the range of push enteroscopy and was well tolerated by patients.
"With enteroscopy, you only see the first third of the small bowel and everyone agrees that the small bowel is 21 feet long. We provide the only way to look at that directly," Gilreath says.
Another trial, recently published in Endoscopy, showed similar results.2 In the trial, 32 patients suffering from chronic GI bleeding received complete conventional diagnostic work-ups, push enteroscopy and capsule endoscopy. The yield of the diagnostic procedures, which included small bowel enteroclysis, angiography and scintigraphy, was 16 percent. The yield of push enteroscopy was 28 perecent whereas capsule endoscopy yielded 66 percent, detecting the definite bleeding sources in 21 of the 32 patients.
Today, more than 20,000 capsules have been ingested, with more than half of those in the United States. The M2A has been utilized to diagnose a range of diseases of the small intestine including Crohns Disease, Celiac disease and other malabsorption disorders, benign and malignant tumors of the small intestine, vascular disorders, and medication related small bowel injury.
Inside View On Costs
The cost of the system, which includes: single-use M2A Capsule Endoscopes, the Sensor Array, the DataRecorder, and the RAPID computer workstation, is $27,000. Additional capsules costs $450 each, sold in 10-packs. Gilreath says that this system is very inexpensive. The capital outlay is the same as for other endoscopes.
"Being able to meet an unmet need is just tremendous for patient care in general," he says. "We have patient after patient saying that 'for so many years I was undiagnosed and finally somebody could look in a place where nobody could look before.'"