A comparison of the diagnostic ability of magnified narrow band imaging and blue laser/light imaging for sessile serrated lesions

Abstract

Purpose The diagnosis of sessile serrated lesions (SSL) and SSL with dysplasia (SSLD) using blue laser/light imaging (BLI) has not been well evaluated. We analyzed the diagnostic ability and specific endoscopic findings of BLI for SSL and SSLD compared to those of narrow band imaging (NBI). Methods We retrospectively reviewed 476 resected lesions from the cecum to the descending colon, which showing Type1 of the Japan NBI Expert Team (JNET) classification completely or partially with magnified NBI or BLI between 2014 and 2021 in our institution. The comparison of the NBI and BLI groups after matching was performed regarding the diagnostic ability of SSL and SSLD. The endoscopic findings of SSL on NBI and BLI were defined as expanded crypt opening (ECO) or thick and branched vessels (TBV) based on previous reports. Additionally, those of SSLD originally defined as network vessels (NV) and white dendritic change (WDC) were analyzed. Results After matching, the sensitivity of lesions with either ECO or TBV for diagnosing SSL and with those with either WDC or NV for diagnosing SSLD in the NBI/BLI were 97.5%/98.5% (p = 0.668) and 81.0%/88.9% (p = 0.667). Regarding the comparison of specific endoscopic findings between the SSLD and SSL, there were significant differences in WDC (66.4% vs. 8.6%, p < 0.001), NV (55.3% vs. 1.4%, p < 0.001), and either WDC or NV (86.8% vs. 9.0%, p < 0.001). Conclusions There was no difference in the diagnostic ability of NBI and BLI for SSL and SSLD. NV and WDC might be useful for diagnosing SSLD.