The diagnostic value of 24-hour ambulatory intraesophageal pH-impedance in patients with laryngopharyngeal reflux symptoms comparable with typical symptoms

Background: The diagnosis of laryngopharyngeal reflux is currently based on a combination of the patient history of multichannel intraluminal impedance and ambulatory pH (MII-pH); however, none of these findings alone is specific for the diagnosis of laryngopharyngeal reflux. We aimed to compare the baseline characteristics and esophageal baseline impedance values between patients with and without laryngopharyngeal reflux symptoms. Methods: We retrospectively analyzed data from two groups of patients with laryngopharyngeal reflux according to their reflux finding score (RFS) as scored by ENTs. Control patients were nonerosive reflux disease patients without laryngopharyngeal reflux. All MII-pH parameters and baseline impedance were analyzed from six levels and the proximal and distal baseline impedance and the ratio of the proximal to distal baseline impedance levels was calculated. Results: Altogether 123 patients with laryngopharyngeal reflux and 49 control patients were included. A total of 81 of 123 patients had RFS >= 7, and 42 of 123 patients had RFS > 7. Baseline impedance analysis showed that patients with laryngopharyngeal reflux symptoms had significantly lower proximal baseline impedance values (1997 +/- 51 vs 2245 +/- 109, p < 0.05) than the control group. Additionally, patients with laryngopharyngeal reflux symptoms had a significantly lower proximal-to-distal ratio (1.28 +/- 0.05 vs 1.53 +/- 0.09, p < 0.05). In the subgroup analysis, patients with RFS < 7 were found to have a significantly lower acid exposure time than either the patients with RFS >= 7 (3.85 +/- 0.65 vs 8.2 +/- 1.52, p < 0.05) or the control group (3.85 +/- 0.65 vs 6.1 +/- 0.81, p < 0.05). Additionally, patients with RFS7 had significantly lower proximal baseline impedance levels than the control group (1970 +/- 63 vs 2245 +/- 109, p < 0.05). Conclusions: Patients with pathologic laryngopharyngeal reflux symptom scores had lower proximal baseline impedance levels and lower proximal-to-distal ratios, which may reflect the proximal mucosal noxious effect of the refluxate. These results may indicate that laryngopharyngeal reflux symptoms may be due to chronic acid exposure in the proximal segments of the esophagus, and the proximal-to-distal ratio may be used as a new metric for diagnosis.