Flexible imaging color enhancement improves visibility of transnasal endoscopic images in diagnosing esophageal varices: a multicenter prospective blinded study.

Objective To clarify the usefulness of transnasal esophagogastroduodenoscope (N-EGD) with all flexible imaging color enhancement (FICE) patterns (0–9) for the diagnosis of esophageal varices (EV). Methods A total of 50 patients with EV were examined during the same period by N-EGD without sedation and by peroral endoscopy (O-EGD) with sedation. The visibility of treatment scars, microvessels, recurrent EV and red color sign (RCS) were measured. Visibility was evaluated by five blinded observers (poor–good: 0–10), and the effect of both endoscopic examinations on the cardiorespiratory function of the patients was measured. Results The image scores for O-EGD and N-EGD with ordinary mode and N-EGD with FICE were 7.3 ± 1.2, 6.1 ± 1.0 and 6.9 ± 1.0 for treatment scars; 7.2 ± 1.4, 6.2 ± 1.2 and 7.3 ± 1.0 for microvessels; 7.2 ± 1.2, 6.1 ± 1.0 and 7.1 ± 1.0 for recurrent EV and 7.2 ± 1.3, 6.1 ± 1.3, and 7.2 ± 1.2 for RCS, respectively (intraclass correlation coefficients > 0.6). When FICE patterns 2, 6 and 9 were used, visibility was much improved. Ten minutes after insertion, the double product values in the N-EGD with the FICE group were significantly better (P < 0.05). Conclusions N-EGD with FICE is very useful for the diagnosis of EV and can improve the visibility of N-EGD on each lesion to the same level as that of O-EGD. N-EGD with FICE does not require sedation and may reduce the risk of hepatic encephalopathy.