Increased polyp detection using narrow band imaging compared with high resolution endoscopy in patients with hyperplastic polyposis syndrome

Background and study aims: Hyperplastic polyposis syndrome (HPS) is associated with colorectal cancer and is characterized by multiple hyperplastic polyps, sessile serrated adenomas (SSAs) and adenomas. Narrow band imaging (NBI) may improve the detection of polyps in HPS. We aimed to compare polyp miss rates with NBI with those of high resolution endoscopy (HRE). Patients and methods: In a single center, randomized crossover study consecutive HPS patients underwent tandem colonoscopy with HRE and NBI, in randomized order with removal of all detected polyps. Results: In 22 patients with HPS, 209 polyps were detected, including 27 with normal histology, 116 hyperplastic polyps, 42 SSAs, and 24 adenomas. Among patients assigned to HRE first (n = 11) a total of 78 polyps was detected; subsequent NBI added 44 polyps. In patients examined with NBI first, 78 polyps were detected and subsequent HRE added 9. Polyp miss rates of HRE and NBI were 36% and 10% (OR 0.21; 0.09-0.45). Flat polyp shape was independently associated with increased miss rate. Conclusion: NBI significantly reduces polyp miss rates in HPS patients. We recommend using either NBI or chromoendoscopy for colonoscopic surveillance of HPS patients with removal of all detected polyps.