Medical Device Daily Associate

An evaluation of a potentially significant new colonoscopy system that has the potential to all but eliminate a very common problem associated with the procedure was presented last week during the 2005 Digestive Disease Week (DDW) meeting in Chicago.

Developed by NeoGuide Systems (Los Gatos, California), the Navigator endoscopy system is designed to enhance physician control of colonoscopes and to eliminate looping, considered one of the primary limitations of colonoscopy.

Colorectal cancer (CRC) is the second-leading cause of cancer deaths in the U.S. and colonoscopy is the “gold standard” for CRC screening, allowing early detection and prevention of the disease.

When performing a conventional colonoscopy, the endoscopist advances the scope and controls a bendable tip. The remainder of the scope’s insertion tube is not controlled. The colon has multiple curves and floats within the abdomen; therefore, as the endoscopist advances the tip through the colon, the scope pushes against the colon wall and stretches the colon and its surrounding tissue.

Looping occurs when the endoscopist attempts to insert the scope further past the obstruction and the tip does not advance. Instead, the scope pushes the colon, forming a large loop. This phenomenon is responsible for the majority of patient pain in colonoscopy. Pain from looping leads to the need for sedation, with its associated expense and risks.

“Looping is the principal reason that many colonoscopy procedures are painful, time consuming, and difficult,” said Amir Belson, MD, president and co-founder of NeoGuide Systems. “We believe that by addressing looping, the Navigator Endoscopy System has the potential to significantly increase the number of colonoscopies that endoscopists are able to perform, which will be particularly important as the demand for the procedure continues to grow.“

Belson told Medical Device Daily that the idea for the company could be traced back to his residency at the Tel Aviv Medical Center (Tel Aviv, Israel). As part of a gastro-enterology elective, Belson performed his first colonoscopy. Using a traditional colonoscope, an optical device mounted on the end of a plastic tube, Belson experienced obstruction within the first 20 centimeters of the patient’s five-foot-long colon.

“I tried twice, and I failed twice,” said Belson. While he noted that this was very frustrating, he discovered that he was not alone. “Most of the attending GIs had the same issue,” he said.

Indeed, Belson noted that looping occurs in more than 90% of all colonoscopy procedures. He added that this pain from looping leads to the need for sedation, with its associated expense and risks. He also pointed out that in many cases, looping leads to incomplete procedures and missed polyps.

NeoGuide was formed in late 2000 when Belson joined forces with two lecturers from Stanford’s (Palo Alto, California) mechanical engineering school, Matt Ohline, the company’s current chief technology officer and electrical engineer group manager, and Craig Milroy.

Belson likened the traditional colonoscope to a semi-pressurized garden hose in which the only thing that can be controlled is the pitch. “You can control it up, down, right and left,” but the colon is very flexible so the colonoscope follows the curve of the colon and causes the painful loops.

The Navigator is designed to traverse the natural shape of the colon, based on a computerized map, generated with the aid of the company’s Foresight computer-assisted technology, so less force is applied to the colon wall, which could potentially eliminate or significantly reduce the incidence of looping.

In addition, the system offers advanced capabilities and procedural features unavailable with conventional colonoscopes, including the ability to display a real-time three-dimensional map of the colon and the ability for physicians to mark the location of polyps on this map, as a sort of GPS system.

Additionally, the company redesigned the colonoscope so that it is segmented, as opposed to the traditional flexible tube. “Those segments are controlled by computer. [The scope] just follows the direction that the physician decided that the device should take” based on what the mapping software revealed.

Jacques Van Dam, MD, professor of medicine at Stanford University School of Medicine (also Palo Alto), presented the results of simulated-use bench testing and in vivo animal studies. Compared to a conventional colonoscope in the bench studies, he said the Navigator applied significantly less force to the colon wall at the sigmoid flexure, which is the primary location of looping in colonoscopy. The in vivo animal studies demonstrated the safety of the Navigator, with no tissue damage or perforations associated with the device.

“Colonoscopy is one of the most frequently performed outpatient examinations,” said Van Dam, the lead investigator for the studies. “However, it is still technically challenging, largely due to unpredictable looping which has been demonstrated to occur in the majority of cases. We believe this device has the potential to have profound implications for colorectal cancer screening, and may thereby represent an important advance for public health.”

While the company believes that the colonoscopy market is a great opportunity all by itself, with about 14 million colonoscopies performed in the U.S. annually and a potential worldwide market for colonoscopy equipment running up to several hundred million dollars, it also believes that its Foresight computer-assisted technology has the potential to address several other large market opportunities in various clinical areas.

“It is clear that this is a real platform technology that you can take to any part of the body where we actually need to control scopes,” Belson said.

The system is still subject to FDA 510(k) review and the company is in the process of putting together clinical trial protocols. At this time NeoGuide said it expects commercial availability of the product in 2006.

The company said it has established a world-class scientific advisory board and has made significant investment in research and development.

To date, NeoGuide has raised a total of $17.5 million dollars from venture investors, including Utah Ventures, Versant Ventures, 3i, Kaiser Permanente Ventures, DC Capital, The Angels Forum, Tenex and Arboretum Ventures, with the most recent $14 million round coming in December 2003. Belson said he thinks the company may need to raise another round sometime before the end of the year to get through clinical trials.

In other news from the DDW meeting:

• Ralf Kiesslich, MD, of Mainz University Hospital (Mainz, Germany) reported 99.2% accuracy in diagnosing colon cancer amongst ulcerative colitis sufferers in a clinical trial using the Optiscan-Pentax endo-microscope.

The trial at Mainz University Hospital assessed 153 patients with an elevated cancer risk due to ulcerative colitis in a randomized prospective blinded protocol. This is the largest clinical study reported so far using Optiscan Imaging’s (Melbourne, Australia) flexible endo-microscope technology.

The protocol had three formal objectives: to evaluate the use of the endo-microscope to predict the outcome of pathology after biopsy; to compare the diagnostic yield of the current “standard of care” procedure (which relies on larger numbers of random biopsies) to the new procedure (use of the endo-microscope to target fewer biopsies); and to measure the ability to detect early cancer with fewer biopsies, using the endo-microscope.

It also was observed in the study that four early cancers were detected in 73 patients by the standard procedure compared to detection of 19 early cancers in 80 patients using the endo-microscope procedure (greater than four-fold increase in yield);

“This technology allows prediction of the outcome of biopsies with a high specificity, sensitivity and overall accuracy,” said Kiesslich. “We therefore believe that a smaller number of ‘smart biopsies, targeted biopsies’ could be taken with a significantly improved diagnostic yield in managing ulcerative colitis.”

Optiscan, a developer of microscopic imaging technologies for medical markets, and Japanese imaging giant Pentax have collaborated over the past three years on the development of the new device, which combines Pentax’s miniaturized camera endoscope technology and Optiscan’s miniaturized microscope technology.