A Diagnostics & Imaging Week

Boston Scientific (Natick, Massachusetts), at the recent Digestive Disease Week (DDW) meeting in Los Angeles, reported on favorable results from an investigator-initiated first-human-use experience and bench simulation study of its SpyGlass direct visualization system for single-operator duodenoscope-assisted cholangiopancreatoscopy (SODAC).

Researchers reported that direct visualization with SpyGlass altered their diagnosis or treatment strategy with most patients who had been previously examined with ERCP (endoscopic retrograde cholangio-pancreotography).

ERCP is a specialized endoscopic procedure that is performed with fluoroscopy and contrast injection to examine and treat conditions of the bile ducts and pancreas, such as removing gallstones, opening obstructed bile ducts, and obtaining biopsies in suspected tumors.

Boston Scientific said conventional ERCP is hindered by the flat, 2-D, black-and-white image rendered by fluoroscopy, which can make it difficult to determine where to obtain tissue samples and potentially lead to an inaccurate or inconclusive clinical diagnosis. As a result, gastrointestinal endoscopists may need to conduct additional testing or even repeat the entire ERCP procedure.

The company said data shows that up to 30% of diagnostic ERCPs are inconclusive, potentially creating the need for additional testing.

"Direct visualization significantly improves the chances of accurately diagnosing and treating a patient in one procedure, thus achieving the full potential of ERCP," said lead investigator Yang Chen, MD, of the Division of Gastroenterology & Hepatology at the University of Colorado Health Sciences Center (Denver). "Bench simulation and animal testing showed that the SpyGlass system was effective for access, direct visualization and biopsy in all bile duct quadrants. In addition, SpyGlass can be performed by a single operator, unlike conventional systems which require two operators."

The SpyGlass system uses a miniature, 6,000-pixel fiber optic SpyGlass probe that attaches to the camera head. The probe is inserted through a single-use access and delivery catheter that can be steered in four directions to access and inspect all four quadrants of the treatment area. The SpyGlass system attaches directly to a standard duodenal scope.

The system is designed to provide direct visualization into the biliary ducts to identify stones and strictures. It includes a monitor, light source, camera and mobility cart; the single-use SpyScope access and delivery catheter; the miniature 6,000-pixel SpyGlass direct visualization probe; and system accessory devices designed to acquire tissue samples and remove stones.

According to investigator and DDW co-presenter Douglas Pleskow, MD, co-director, endoscopy and director of the Colon Cancer Center at Beth Israel Deaconess Medical Center (Boston), "We used the SpyGlass system to examine and treat 22 patients. The use of SpyGlass altered the initial ERCP impression and ultimately changed patient treatment strategy in most patients."

Steve Moreci, Boston Scientific senior vice president and group president, endosurgery, said, "These studies indicate that the SpyGlass direct visualization system has the potential to redefine how ERCP is performed and to potentially help physicians obtain a more accurate diagnosis quickly. We look forward to formally making the system more broadly available to the GI community sometime next year."

In other news from DDW:

• Exact Sciences (Marlborough, Massachusetts) reported results of a study regarding a potential new application of its stool DNA testing technologies at the "Biomarkers and GI Cancers Research Forum."

The study, discussed in a presentation titled "Expression of Multiple Simultaneous Biomarkers in Tissues of Patients with Colitis-Associated Neoplasia," describes data from a tissue study evaluating the sensitivity of a prototype marker panel targeting alterations in ulcerative colitis carcinogenesis. Ulcerative colitis and Crohn's colitis are collectively known as inflammatory bowel disease, or IBD.

According to the National Institutes of Health, IBD affects as many as 1 million people in the U.S., and individuals with longstanding IBD are at increased risk for developing colorectal cancer. Exact Sciences said the heightened inflammation associated with IBD makes it more difficult to detect colorectal neoplasia with colonoscopy than in those without IBD, so approaches that are complementary to colonoscopy are being actively explored.

"We believe that stool DNA holds great promise in this regard," the company said. "Because inflammation often affects wide areas of the colon in IBD patients, and since cancerous lesions arise from these areas, there is the potential for more cells with mutated DNA to be shed into the stool than in an average individual."

In their preliminary results, researchers found that colitis-associated neoplasia (CAN) could be detected in tissue using a prototype marker set. Because the molecular progression of CRC in IBD patients differs markedly from that in average risk individuals, a refined configuration of markers needs to be evaluated, the company said. "If follow-up studies confirm this, stool DNA testing may be helpful as a partner to colonoscopy in detecting colorectal cancer in the large population of IBD sufferers," it said.

"Using this prototype molecular marker panel, we detected 44% of colitis-associated neoplasias," said Steven Itzkowitz, MD, professor and associate chief, Division of Gastroenterology, Mount Sinai School of Medicine. "Given the often multi-focal nature of neoplasia in colitis, it is possible that stool diagnostics might perform better than analyzing tissue."

Digestive Disease Week is a leading gathering of physicians, researchers and academics in the fields of gastroenterology, hepatology, endoscopy and gastrointestinal surgery. It is jointly sponsored by the American Association for the Study of Liver Diseases, the American Gastroenterological Association, the American Society for Gastrointestinal Endoscopy and the Society for Surgery of the Alimentary Tract and showcases about 5,000 abstracts and hundreds of lectures on the latest advances in GI research, medicine and technology.

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