Additional Thirty Seconds Observation with Linked Color Imaging Improves Detection of Missed Polyps in the Right-Sided Colon

Background and Aims. Missed polyps are a pitfall of colonoscopy. In this study, we analyzed the efficacy of an additional 30 seconds observation using linked color imaging (LCI) for detecting adenoma and sessile serrated adenoma/polyp (SSA/P). Materials and Methods. We enrolled patients undergoing colonoscopy from February to October 2017 in two institutions. In all patients, the cecum and ascending colon were observed with white light imaging (WLI) first. The colonoscope was inserted again, and the cecum and ascending colon were observed for an additional 30 seconds using either LCI or WLI. The method for the 30 sec observation was to insufflate the cecum and ascending colon sufficiently and observe them in a distant view, because the length of the second observation was determined to be precisely 30 sec. For the second observation, LCI was performed for the first 65 patients and WLI for the next 65. Adenoma and SSA/P detection rate (ASDR) in the second observation were examined in both groups. According to a pilot study, the sample size was estimated 65. Results. In the first observation, ASDR were 30.7% in the LCI group and 32.2% in the WLI group (p=0.85). For the second observation, 13 polyps were detected in the LCI group and 5 polyps in the WLI group (p=0.04). Additionally, ASDR for the second observation were 18.5% and 6.1%, respectively (p=0.03). There were no significant differences between the LCI and WLI groups with respect to morphology (ratio of polypoid) (38.5% versus 60.0%, p=0.52) and histology (ratio of adenoma) (92.3% versus 100.0%, p=0.91). Total adenoma and SSA/P number were 48 in the LCI group and 36 in the WLI group (p=0.02). Conclusion. The 30 seconds additional observation with LCI improved the detection of adenoma and SSA/P in the right-sided colon