Prediction of the efficacy of proton-pump inhibitors in patients with contact granuloma using 24-hour combined dual channel pH/impedance monitoring

Objectives We aimed to evaluate the treatment outcomes of proton-pump inhibitors (PPIs) in patients with contact granuloma (CG) and to investigate the parameters of 24 h combined dual channel pH/impedance (24 h pH/MII) monitoring, which are reliable for predicting the response to PPI of CG patients. Methods : We reviewed the medical records of patients with CG who had been treated with PPIs and had completed more than 6 months of follow-up. We classified the patients into two groups (cured vs. persistent), according to their PPI treatment outcomes. Reflux events were categorized into three groups based on pharyngeal pH during reflux: 1) acid reflux (pH < 4), 2) weak acid reflux (4 < pH < 7), and 3) weak alkaline reflux (pH >7), as detected by a proximal probe. We compared the results of 24h-pH/MII between the two groups and used receiver operating characteristic curve (ROC) analysis to determine the cutoff values of significant parameters for predicting responses to PPIs. Results : Among 22 patients who completed at least 6 months of PPI treatment and follow-up, weak acid reflux events were more frequently observed in persistent group than in the cured group (p = 0.046), and the proportion of weak acid reflux was also higher in the persistent group (p = 0.031) than in the cured group. Reliable parameters predictive of a poor response to PPIs were a number of weak acid reflux events ≥ 11 (area under the curve [AUC], 0.775; p = 0.03) and a proportion of weak acid reflux events ≥ 56.7 % (AUC, 0.763; p = 0.038) in ROC analyses. Conclusion : Weak acid reflux was identified as a significant factor associated with the treatment outcomes of PPIs in patients with CG. A number of weak acid reflux events ≥ 11 is considered to be the most reliable predictor of a poor response to PPIs in patients with CG.