The utility of narrow band imaging in endoscopic diagnosis of laryngopharyngeal reflux

Objective: This study assessed the utility of narrow band imaging (NBI) in patients with symptoms of laryngopharyngeal reflux (LPR) and tried to quantitatively evaluate the signs found under the NBI Laryngoscope. Methods: Patients with and without LPR symptoms completed reflux symptom index (RSI) questionnaires prior to enrolment. The throat was examined by standard white light endoscopy followed by NBI. LPR status was determined using the reflux finding score and the RSI. Laryngoscope images and videos from 70 subjects with LPR and 70 control subjects without LPR were obtained. Features seen only by NBI were compared between the two groups. Then the RGB values of the throat mucosa of the two groups were measured by Photoshop software, and finally statistical analysis was performed. Results: In total, 140 patients were eligible for final analysis (LPR group mean age = 50.0, 47 males; control group mean age = 44.8, 45 males). A significantly higher proportion of patients with LPR had increased vascularity, green spots, contact ulcers and granulomas. Of these, increased vascularity and green spots can only be found under NBI, and the prevalence rates in the LPR group were found to be 92.8% and 88.6% (P < 0.05), respectively. In the control group, the prevalence rates of increased vascularity and green spots were 21.4% and 7.1%, respectively (P < 0.05). The RGB value of the LPR group was generally higher than that of the control group. The difference is statistically significant (P < 0.05). Conclusion: LPR presents vascularity and green spots with high specificity and sensitivity under NBI which can play a role in the auxiliary diagnosis of LPR.