January 14, 2013
New Pill-Sized Device Detects Esophagus Conditions Easier Than Expensive Endoscopy
Lawrence LeBlond for redOrbit.com - Your Universe Online
Doctors may soon have a new method for checking for cancers and other ailments of the esophagus thanks to a pill-sized device that can take microscopic images as it is fed down through the throat.
Scientists hope the new technology can become an easier way to screen people for a condition known as Barrett´s esophagus, a precancerous condition usually caused by chronic exposure to stomach acid. Unlike current imaging techniques, the device can be used while the patient is conscious and takes only a few minutes to perform the procedure.
Researchers from the Wellman Center for Photomedicine at Massachusetts General Hospital (MGH) were the team behind this new device. They said their little clear pill, which is about the size of a multivitamin, creates a detailed, microscopic image of the esophagus wall, and has several advantages over traditional endoscopy.
"This system gives us a convenient way to screen for Barrett's that doesn't require patient sedation, a specialized setting and equipment, or a physician who has been trained in endoscopy," said Gary Tearney, MD, PhD, corresponding author of the study published online in Nature Medicine.
"By showing the three-dimensional, microscopic structure of the esophageal lining, it reveals much more detail than can be seen with even high-resolution endoscopy,” added Tearney.
The new device contains optical frequency domain imaging (OFDI) technology with a rapidly rotating laser tip that emits a beam of near-infrared light and sensors to record light reflected off the esophageal lining. The capsule is attached to a small tether that connects to the imaging device, allowing the health professional the ability to control the system the whole time.
Once the patient swallows the device, it is carried down through the esophagus by normal contraction of the muscles. When the capsule reaches the entrance to the stomach, it can then be pulled back up via the tether. Images of the esophageal wall are taken throughout the capsule´s journey, both down and back up the esophagus.
Doctors can see the images immediately on a screen, showing a 3D landscape with far more detail than with a traditional endoscopy.
The research team tested the new device on six patients who were known to have Barrett´s esophagus. They also tested it on seven healthy patients. The team said the images clearly showed the cellular changes that occurred in those with the precancerous condition.
The scientists said they were able to image the entire esophagus in less than a minute on a single pass. And after making four passes (two down and two up), researchers were able to complete the experiment in about six minutes.
This has significant implications as a traditional endoscopy requires upwards of 90 minutes of a patient´s time, and involves sedation. This new method takes only minutes and the patient is conscious the entire time. And the OFDI system revealed subsurface structures that traditional endoscopy could not easily pick up. Furthermore, the OFDI system was able to easier distinguish the cellular changes involved with Barrett´s esophagus than endoscopy was.
And perhaps the best part, it is far cheaper than endoscopy–good news for insurance companies that can typically dish out $5,000 to $8,000 for the 90-minute procedure; the new system could cost well under $2,500. To top it all off, the study patients who said they had undergone endoscopy in the past showed preference toward the new procedure.
Tearney said the new device produces such a clear image that a biopsy can likely be avoided.
"We originally were concerned that we might miss a lot of data because of the small size of the capsule; but we were surprised to find that, once the pill has been swallowed, it is firmly 'grasped' by the esophagus, allowing complete microscopic imaging of the entire wall. Other methods we have tried can compress the esophageal lining, making it difficult to obtain accurate, three-dimensional pictures. The capsule device provides additional key diagnostic information by making it possible to see the surface structure in greater detail,” Tearney said in a statement.
Current recommendations for diagnosis of Barrett´s oesophagus call for endoscopic screening of men with chronic heartburn and other symptoms of gastroesophageal reflux disease (GERD).
“An inexpensive, low-risk device could be used to screen larger groups of patients, with the hope that close surveillance of patients found to have Barrett's could allow us to prevent esophageal cancer or to discover it at an earlier, potentially curable stage. But we need more studies to see if that hope would be fulfilled,” study co-author Norman Nishioka, MD, said in a statement.
"It is elegant technology. The downside is that you will have to endoscope anyone with suspected Barrett's as you will have no way of sampling and detecting dysplasia [abnormalities] with this technology," Professor Rebecca Fitzgerald, a Barrett´s oesophagus specialist at the Cambridge Cancer Centre, told BBC News in an interview.