'Capsule colonoscope' could pave the way for more colorectal cancer screenings

The 18mm capsule colonoscope is attached to a tether that is thinner than traditional endoscopes, which improves patient comfort and may reduce the need for sedation during colonoscopy.

While colorectal cancers are a leading cause of cancer death in the U.S., many tend to avoid diagnostic colonoscopy. A new “capsule colonoscope” could lead to a more comfortable colonoscopy experience and encourage more people at risk of colorectal cancer to undergo the procedure.

Colorectal cancer is the third most common cancer diagnosed in the U.S.—the American Cancer Society estimated that more than 135,000 new cases will be diagnosed this year. The CDC recommends a range of tests to screen for colorectal cancers for people aged 50 to 75, including stool tests, CT imaging and colonoscopy.

But, as a 2015 study found, people avoid colonoscopy for a number of reasons: Some think it’s too expensive, while others don’t think they need it. Others still just dislike the procedure.

"There's no doubt in the value of colonoscopies to keep people healthy through preventive screening for colon cancer, but many individuals still avoid this procedure, because of fear of the test itself, perceived discomfort or the risk of sedation," said Keith Obstein, an associate professor of medicine at Vanderbilt University Medical Center and corresponding author of the study, in a statement. "We developed this capsule robot to make traversing the GI tract much easier, for both the clinician and patient."

The research was presented at Digestive Disease Week in Chicago and was supported by the National Institute of Biomedical Imaging and Bioengineering.

The capsule measures 18mm and is inserted via the rectum. It is attached to a tether that is thinner than a typical endoscope. It is guided through the colon by an external magnet attached to a robot arm, rather than have a physician physically push the device through a patient’s colon, according to the statement.

"[We’re] able to avoid much of the physical pressure that is placed on the patient's colon—possibly reducing the need for sedation or pain medication,” Obstein said.

The team deployed the capsule 30 times in the colon of a pig and found it was able to bend backwards at the press of a button to give the endoscopist a “reverse-view” of the colon wall. They will work on improving the algorithms that move the robotic arm and expect to kick off human trials of the device at the end of 2018.

Using a capsule to screen for colon cancer is not new—Medtronic’s Pillcam is an ingestible capsule indicated for the detection of polyps in patients who didn’t manage to undergo a complete colonoscopy. In March last year, the FDA expanded the device’s indication to include patients at high risk for colonoscopy or moderate sedation,

What sets the capsule colonoscope apart though, is the tether.

"Not only is the capsule robot able to actively maneuver through the GI tract to perform diagnostics, it is also able to perform therapeutic maneuvers, such as biopsies of tissue or polyp removal, due to the tether—something that other capsule devices are unable to do," Obstein said.