Advances in Eustachian tube function testing

Abstract

Obstructive and patulous Eustachian tube dysfunction provide a significant diagnostic and management challenge. The development of new treatments such as balloon Eustachian tuboplasty has generated renewed interest in measuring Eustachian tube function, as a method of selecting appropriate patients for intervention, and measuring their treatment outcomes. This review summarises recent findings relating to Eustachian tube function assessment. Increasingly it is recognised that patient reported outcome measures based on symptoms are highly non-specific and non-diagnostic, and clinical assessment alone may not permit the selection of individuals with abnormal Eustachian tube opening. Tests of Eustachian tube opening therefore may represent a practical and objective addition to patient assessment in clinic, allowing the identification of individuals with abnormal (patulous or obstructive) Eustachian tube function. A diagnostic pathway is described on this basis. More work is required to validate the described Eustachian tube function tests, and there remain individuals, such as those with dysfunction limited to pressure challenges, in whom function tests have yet to fully characterise the disorder.

Keywords: Accuracy; Diagnosis; Eustachian tube; Function; Test.

Fig. 1

Proposed diagnostic flow chart for ETD (reproduced from Smith et al. 2018³¹). ^{a, b}Clinical assessment may not be diagnostic of ETD, but remains a means to identify patients for investigation. ^c Effort should be made during assessment of the clinical history to identify habitual sniffing, as a negative middle ear pressure in these individuals may not indicate obstructive ETD, and further testing should be undertaken. ^d Described diagnostic thresholds may require adjustment based on local test methodology. ^e TTAG is recommended if a tympanic membrane perforation is present. ^f A simple provocation test for use in clinic is asking the patient to exercise prior to testing. ^g Consider repeating tests on a separate occasion to improve sensitivity in patients with variable ET function. Patients with baro-challenge induced obstructive ETD may present in this group.