Additional 30-second observation of the right-sided colon for missed polyp detection with linked color imaging compared with narrow band imaging.

Background and study aims We previously demonstrated the efficacy of an additional-30-seconds (Add-30s) observation with linked color imaging (LCI) or narrow band imaging (NBI) of the cecum and ascending colon (right-sided colon) after white light imaging (WLI) observation for improving adenoma detection rate (ADR) by 3% to 10%. We herein compared Add-30s LCI with Add-30s NBI in a large number of cases. Patients and methods We retrospectively collected 1023 and 1011 cases with Add-30s LCI and NBI observation for right-sided colon in 11 affiliated institutions from 2018 to 2022 and propensity score matching was performed. Add-30s observation was as follows. First observation: WLI observation of the right-sided colon as first observation. Second observation: Reobservation of right-sided colon by Add-30s LCI or NBI. The comparison of the mean numbers of adenoma+sessile serrated lesions (SSLs) and adenomas per patient (MASP and MUTYH-associated polyposis) were analyzed in the Add-30s LCI/NBI groups. The increase in right-sided ADR was also analyzed in the groups. Results Among 748 matched cases in the Add-30s LCI/NBI groups, the MASP and MAP were 0.18/0.19 ( P = 0.54) and 0.14/0.15 ( P = 0.70). Among experts, they were 0.17/0.22 ( P = 0.16) and 0.15/0.21 ( P = 0.08). Among non-experts, they were 0.13/0.12 ( P = 0.71) and 0.12/0.07 ( P = 0.04). The right-sided ADRs of the first+second observations in the LCI and NBI groups were 32.2% and 28.9% ( P = 0.16) and the increase of ADRs were 7.5% and 7.2% ( P = 0.84). Conclusions In right-sided colon, the detection of adenoma/SSL did not differ between Add-30s LCI and NBI. Both of them significantly increased ADR.