Comparison of sonotubometry, impedance, tubo-tympano-aerography, and tubomanometry to test eustachian tube function

Abstract Purpose There is currently no gold standard for the diagnosis of eustachian tube (ET) dysfunction. To provide an objective basis for the clinical diagnosis of ET dysfunction, we explored the characteristics of sonotubometry, impedance, tubo-tympano-aerography (TTAG), and tubomanometry (TMM) in volunteers with healthy ETs. Materials and methods Sonotubometry, impedance, TTAG, and TMM tests were performed in 110 healthy ears of 55 volunteers, and the characteristics of each ET test were compared and discussed. Results The ET opening rate was compared between sonotubometry with dry swallowing, impedance with the Valsalva maneuver, TTAG with the Valsalva maneuver, and TMM with a nasopharyngeal pressure of 50 mbar in 100 (90.9%), 102 (92.7%), 99 (90.0%), and 104 (94.5%) ears, respectively; there was no significant difference among the four methods (P = 0.575). In sonotubometry, both dry swallowing and the Valsalva maneuver were superior to wet swallowing in terms of detecting ET opening (P = 0.000). In TMM, both the opening rate and the external auditory canal pressure were positively correlated with the nasopharyngeal pressure. Specifically, the opening rate and external auditory canal pressure increased with an increase in the nasopharyngeal pressure (r = 0.271, P = 0.000; r = 0.315, P = 0.000, respectively). Conclusions Sonotubometry, impedance, TTAG, and TMM have their own advantages and disadvantages. In clinical practice, the appropriate ET function test should be chosen on the basis of the patient's specific condition.