New Colonoscope to Detect Polyps
San Diego—Endoscopists who used a high-definition, dual-focus colonoscope were >2 times as likely to detect diminutive (≤5 mm) polyps and had a significantly higher proportion of accurate predictions compared with those who used a standard colonoscope. The new colonoscope is able to get within 2 mm of the polyp and still remain in focus.
The authors of the study, Tonya Kaltenbach, MD, and Roy M. Soetikno, MD, who work in gastroenterology at Palo Alto Veterans Hospital in California, presented the results at DDW. Olympus America Inc., the product’s manufacturer, partially funded the multicenter, prospective, randomized, controlled study.
The VALID (Veterans Affairs Colorectal Lesion Interpretation and Diagnosis) study included 558 patients at Veterans Affairs hospitals in Palo Alto, California, and Kansas City, Missouri, who underwent routine colonoscopy.
Dr. Soetikno said colorectal cancer is the second leading cause of cancer death in the United States. Although 99% of polyps are benign, the standard of care during a colonoscopy is to remove the polyps and have pathologists examine them, contributing to high costs, according to Dr. Soetikno. He said the costs in the United States could reach as high as $1 billion.
Dr. Soetikno added that in some pathology units, 20% to 30% of the workload is spent looking at polyps. In fact, as technology gets better, 60% to 65% of patients are found to have polyps.
In addition to high costs, pathology has other potential issues, according to Dr. Kaltenbach. It may be difficult to retrieve the specimen, there could be disagreement in the diagnosis, and there is typically a long delay (days or weeks) before patients receive the results after they undergo the colonoscopy.
A previous pooled analysis showed that real-time polyp diagnosis has an overall accuracy of 86%. Before implementing real-time diagnosis into clinical practice, Dr. Kaltenbach said it must meet standardized endoscopic criteria and clinical guidelines and must be cost neutral or save money. Endoscopists must also be able to make clinical decisions with high confidence.
In the VALID study, the researchers assigned the patients to 5 doctors who randomly used the new or old colonoscope for endoscopy. They had a standard diagnosis using a validated Narrow-Band Imaging International Colorectal Endoscopic classification and learning module. Patients were excluded if they had irritable bowel disease, polyposis, coagulopathy or thrombocytopenia, or emergency endoscopy.
When the doctors detected a polyp, they made a histologic prediction: neoplasia or nonneoplasia, high or low confidence, proposed management, and surveillance interval. The polyps were removed and sent to pathology.
Of the patients, 277 were randomized to the dual-focus group and 281 to the standard colonoscope. The arms were well balanced, with a mean age of approximately 63 years and 95% males.
The doctors detected 1309 polyps (710 in the dual-focus group and 599 in the standard-focus group). Nearly three quarters of the polyps were ≤5 mm.
The endoscopists were twice as likely to make a high confidence diagnosis in the diminutive polyps using the dual-focus colonoscope compared with the standard colonoscope (odds ratio [OR], 2.2; P<.0001). There was also a significantly higher proportion of accurate high confidence endoscopic predictions using the dual-focus colonoscope (OR, 1.9; P=.035).
Dr. Kaltenbach said that using the dual-focus colonoscope did not significantly lengthen the procedure time. The mean real-time diagnosis time was 20 seconds, the mean inspection time was 10 minutes, and there was no bleeding or perforation. She added that both procedures met the Preservation and Incorporation of Valuable Endoscopic Innovations criteria from the American Society for Gastrointestinal Endoscopy to practice real-time endoscopic diagnoses.
