Polyps diagnosed more often with high-definition endoscope vs. high-definition colonoscope

SAN DIEGO — Endoscopists were twice as likely to diagnose minuscule polyps with high confidence using a dual focus, high-definition endoscope rather than a conventional high-definition colonoscope, according to data presented at the 2012 Digestive Disease Week Annual Meeting.

While prior studies have shown that endoscopists can diagnose polyp histology (neoplasia vs. non-neoplasia) accurately using high-definition colonoscopes with image enhancement (CHFH180), the endoscopists typically lack confidence in their diagnosis. A new pre-commercial colonoscope (CFHQ190) allowed detailed polyp imaging with dual near and standard focus, and brighter Narrow Band Imaging.

In an attempt to reduce reliance on pathology analysis, Tonya Klatenbach, MD, and colleagues from the Veterans Affairs Palo Alto Care System, compared current colonoscope technology with pre-commercial technology.

Researchers compared the accuracy and confidence of Narrow Band Imaging diagnoses of diminutive polyps by five colonoscopists, using two randomly assigned colonoscopes: CFHQ190 vs. CHFH180. Diagnosis was standardized using a validated NBI International Colorectal Endoscopic (NICE) classification and learning module.

For each polyp, endoscopists stated the diagnosis (neoplastic vs. nonneoplastic) and confidence level in the diagnosis (high vs. low); then removed and submitted it for final histopathologic diagnosis by blinded, central pathologists. Initial endoscopic polyp diagnoses and surveillance recommendations were compared to final histopathologic diagnosis and surveillance recommendations.

According to the study results, 748 polyps — predominantly d5mm (74.3%), neoplastic (65.6%) and right sided (51.2%) — were detected in 311 subjects in the study arms. Endoscopists were found to be twice as likely to make a high confidence diagnosis in diminutive polyps using CFHQ190 (84.6%) than with CFH180 (71.5%) (OR, 2.0; 95% CI,1.4-3.0; P=0.0006).

The mean diagnosis time per polyp was 22 ± 19 seconds using either model. However, researchers found 95% agreement in the surveillance interval periods made using CFHQ190, and 93% using CFH180, as compared to those made based on pathology results. Overall, the researchers exhibited a 78% polyp and 63% adenoma detection rate.

“By reducing the number of polyps sent for pathology analysis, we can significantly reduce unnecessary spending,” Kaltenbach said in a press release. “The ability to be confident with the diagnosis during colonoscopy and document our diagnoses with a high-quality polyp image may be all we need to start diagnosing polyps right then and there, making colonoscopy better for our patients.”

For more information:

Kaltenbach T. #569: The Valid Colonoscopy Study - Results of a Multicenter Prospective Randomized Controlled Trial on Real Time Colorectal Polyp Diagnosis Using Narrow Band Imaging (NBI). Presented at: the 2012 Digestive Disease Week Annual Meeting; May 19-22, 2012; San Diego.