Diagnostic utility of tubomanometry for patulous eustachian tube: A comparative study

PURPOSE: The current diagnosis of patulous Eustachian tube (PET) has limitations and cannot accurately assess its functional status. This study aims to validate tubomanometry (TMM) as an objective diagnostic tool for PET by analyzing pressure-specific R-values. METHODS: A retrospective cohort study was conducted involving 95 ears from 64 patients which were stratified into three groups: Definite PET (n = 26), Possible PET (n = 41), and Controls (n = 28). Diagnostic performance was evaluated by receiver operator characteristic (ROC) curve analysis to determine optimal R-value thresholds. RESULTS: The Definite PET group exhibited significantly lower R-values compared to the Possible PET and Control groups at all pressure levels (30 mbar: 0.27 ± 0.39 vs 0.40 ± 0.34 vs 0.99 ± 0.49, p < 0.001; 40 mbar: 0.39 ± 0.55 vs 0.54 ± 0.44 vs 0.75 ± 0.31, p = 0.001; 50 mbar: 0.32 ± 0.33 vs 0.41 ± 0.33 vs 0.70 ± 0.32, p < 0.001). The optimal diagnostic threshold was achieved at 30 mbar (R-value cutoff: 0.585; sensitivity: 75%, specificity: 77%, area under curve [AUC]: 0.802). Asymptomatic contralateral ears in unilateral PET cases exhibited R-values that were similar to healthy controls (p > 0.05). CONCLUSION: TMM is a robust diagnostic tool for PET, with optimal clinical utility at 30 mbar. Pressure-specific R-value thresholds can differentiate the severity of PET and validate the status of asymptomatic ears in unilateral cases.