New Device Improves Polyp Detection in the Colon

SAN DIEGO – At the Digestive Disease Week conference in San Diego (DDW 2008), world-renowned gastroenterologist Jerome D. Waye, MD, presented clinical results from a multi-institutional study which evaluated the efficacy of the Third Eye™ Retroscope™, a new device that improves the ability of physicians to visualize abnormalities in the colon.

The study showed that the Third Eye Retroscope, when used in combination with a standard colonoscope, detects a significantly higher number of adenomas and other polyps than the colonoscope alone. The Third Eye Retroscope has been cleared for use in the U.S. by the Food and Drug Administration (FDA).

"It is quite an ingenious device," said Waye. "The technology behind it is amazing."

Principal investigator Waye, of Mount Sinai Hospital in New York, presented the study results yesterday afternoon in front of physicians and other industry professionals during the conference, being held at the San Diego Convention Center. The multi-center study has evaluated 214 patients to date at eight sites across the U.S. During the study, patients were examined using a Third Eye Retroscope in combination with a standard colonoscope. The abstract of the study by Waye and his co-authors was accepted for publication by the DDW review panel of the American Society for Gastrointestinal Endoscopy (ASGE). Waye was also invited to present the abstract during this week’s annual conference.

"Colonoscopy is currently considered the best method for colorectal cancer screening. However, it is well-established from previous research that lesions may be missed, especially on the proximal aspect of haustral folds and flexures or behind the ileocecal valve," said Waye.

Used during colonoscopy, the Third Eye Retroscope is an auxiliary imaging device that provides retrograde illumination and visualization of the colon for diagnostic purposes. Developed by Avantis Medical Systems, Inc. of Sunnyvale, Calif., this innovative new endoscopic device is passed through the instrument channel of a standard colonoscope until it extends beyond the tip of the colonoscope. As it emerges, the device automatically turns around 180 degrees to provide a continuous retrograde view while the colonoscope is being withdrawn.

Colonoscopy is widely regarded as the "gold standard" for detection of abnormalities in the colon. However, previous research has revealed that 12-24 percent of polyps and a significant number of cancers can be missed during colonoscopy, especially if they lie behind folds in the colon wall.^1,2,3 This new device is designed to solve this problem by allowing the physician to view the opposite side of those folds during the procedure.

The study (which is still active) has found that, in combination with a standard colonoscope, the Third Eye Retroscope detected 13.3 percent additional polyps, and 12.4 percent additional adenomas, compared with the colonoscope alone. Polyps detected with the Third Eye were comparable in size to those seen with the colonoscope.

"Our investigators are finding that the Third Eye Retroscope is a promising new technology for improving visualization during colonoscopy," continued Waye. "During the study, the Third Eye revealed areas that are often hidden from the forward-viewing colonoscope, and it allowed a significant increase in detection of adenomas and other polyps."

In the 214 patients studied to date, 203 polyps were identified with the standard colonoscope. With the Third Eye Retroscope, an additional 27 polyps were detected, an increase of 13.3 percent. With the standard colonoscope, 105 adenomas were found; and with the Third Eye Retroscope, an additional 13 adenomas were detected, an increase of 12.4 percent. Mean size for polyps found by the colonoscope alone was 0.49 cm, and mean size for polyps found by the Third Eye Retroscope was virtually identical, at 0.47 cm.

In 21 patients (9.8 percent), at least one additional polyp was found with the use of the Third Eye Retroscope, and in seven patients (3.3 percent), the polyp detected with the Third Eye Retroscope was the only one found.

Waye is clinical professor of medicine and chief of the GI endoscopy unit at the Mount Sinai Medical Center in New York City.

Known for introducing the concept of colonoscopy without fluoroscopy by defining endoscopic landmarks, Waye has authored seven books, innumerable abstracts, and has published almost two hundred scientific papers in peer-reviewed journals. He is president-elect and has been treasurer of OMED, the international organization for digestive endoscopy. In 1980, he was president of the ASGE and in 1982 became president of the American College of Gastroenterology (ACG). He has also received the highest honors awarded by these organizations: the Schindler Award (from the ASGE) and the Founder's Award (from the ACG).

He is organizing the International Congress of Endoscopy, to be held in Los Angeles, Calif., in 2011.

About the Study
Study sites included Mayo Clinic, Scottsdale, Ariz.; MD Anderson Cancer Center—University of Texas, Houston; Indiana University, Indianapolis; University of Michigan, Ann Arbor, Mich.; Camino Medical Group & El Camino Hospital, Mountain View, Calif.; and Washington University, St. Louis, Mo. Although the original published abstract reported on the initial 100 patients in the study, Waye’s DDW presentation reported on the study’s initial 214 patients.

About the Technology
The Third Eye Retroscope is designed to complement, not to replace, standard colonoscopes. Therefore it does not alter existing procedural infrastructure or referral patterns, and does not require major outlay from medical facilities for capital equipment. The device can be used with most of the adult colonoscopes currently produced by the leading manufacturers, as well as some pediatric colonoscopes.

The "chip-on-catheter" platform for the Third Eye Retroscope is also the basis for a number of other products that Avantis is developing for use in gastroenterology, and in other medical and surgical specialties. Like the Third Eye Retroscope, most of these innovative devices are designed to be disposable, which eliminates the need for sterilization and the risk of contamination.

References
1. Pickhardt, P.J.; Nugent, P.A.; Mysliwiec, P.A.; Choi, J.R.; Schindler, W.R. Location of adenomas missed by optical colonoscopy. Annals of Internal Medicine 141(5):352-360, 2004.
2. Pabby, A.; Schoen, R.E.; Weissfeld, J.L.; Burt, R.; Kikendall, J.W.; Lance, P.; Shike, M.; Lanza, E.; Schatzkin, A. Analysis of colorectal cancer occurrence during surveillance colonoscopy in the dietary Polyp Prevention Trial. Gastrointestinal Endoscopy 61(3):385-391, 2005.
3. Rex, D.K.; Cutler, C.S.; Lemmel, G.T.; Rahmani, E.Y.; Clark, D.W.; Helper, D.J.; Lehman, G.A.; Mark, D.G. Colonoscopic miss rates of adenomas determined by back-to-back colonoscopies. Gastroenterology 112(1):24-28, 1997.