Learning Objectives: To understand a novel method of measuring ET dysfunction.
Introduction: Eustachian tube (ET) dysfunction is a common and varied condition with significant associated morbidity. In most cases it is caused by a failure of the ET to adequately open, however there is currently no reliable method of assessing this opening. Tubomanometry is a test that has recently shown good inter-individual repeatability as a measure of ET opening and function, by measuring middle ear pressure after the application of regulated nasopharyngeal pressures during swallowing. We present the first reports of a novel test: middle ear impedance measurements during standardised nasopharyngeal positive pressure bursts (tuboimpedance). We assess repeatability in healthy ears, and whether this new assessment provides any advantages over tubomanometry.
Methods: Ethical approval was obtained. Tubomanometry and tuboimpedance assessments were performed in 20 screened, healthy ears (10 volunteers). Each ear underwent tests while the patient swallowed a water bolus during applied nasopharyngeal pressures of 20, 30, 40 and 50mbar. Immediate and delayed repeats were performed at each pressure.
Results: ET opening was detected more frequently with the tuboimpedance method, with a 100% detection rate using a nasopharyngeal pressure of 30mbar or more. ET opening at 20mbar was detected more frequently with tuboimpedance. Repeatability of both tests, as measured by Intraclass Correlation Coefficient, was very good for both immediate and delayed repeats. Repeatability for the tubomanometry R value was mixed.
Conclusions: Tuboimpedance may provide a repeatable measure of ET opening that is easier to perform, due to lower required nasopharyngeal pressures and fewer issues with poor ear-probe sealing. Further assessment in patients with different forms of ET dysfunction is required.