Assessing Eustachian tube passage and active opening with the Valsalva maneuver: Diagnostic performance, limitations,...

To clarify the diagnostic performance and limitations of the Valsalva maneuver for assessing Eustachian tube (ET) function. We evaluated the quantitative and qualitative accuracy of the Valsalva maneuver for detecting stenotic ET and assessed its practical limitations related to unassessable results. We also examined its applicability for assessing active ET opening and determined the optimal external auditory canal sound-pressure amplitude (EAC-SPA) threshold for sonotubometry.

This retrospective study analyzed a single clinical cohort using standardized ET function-testing procedures. The study comprised three analytic components: (1) diagnostic accuracy of the Valsalva maneuver compared with the passage test, a high-precision reference standard for ET passage (n = 105 ears); (2) determination of the optimal EAC-SPA threshold using receiver operating characteristic (ROC) analysis, with the inflation-deflation test (IDT) as the reference standard for active ET opening (n = 100); and (3) applicability of the Valsalva maneuver for assessing active ET opening, compared with sonotubometry and IDT (n = 100).

Quantitative accuracy of the Valsalva maneuver for evaluating ET passage was limited: the correlation between Valsalva opening pressure (VOP) and passive opening pressure (POP) from the passage test was weak (Spearman's r = 0.28, p = 0.018), and VOP did not provide statistically reliable screening performance for POP-defined stenotic ET (AUC = 0.63; p = 0.11). In contrast, qualitative assessment using the Valsalva maneuver showed high specificity (98%) for detecting POP-defined stenotic ET. However, 25% of Valsalva results were unassessable for ET passage because nasopharyngeal pressure did not reach the recommended level of 650 daPa or because waveforms were atypical or uninterpretable. Sonotubometry demonstrated moderate diagnostic performance for identifying ears without active opening on IDT (AUC = 0.72; p = 0.0002), and 9.1 dB was identified as the optimal EAC-SPA threshold. Only 43% of tests were assessable for active opening using the Valsalva maneuver alone. Nevertheless, combining the Valsalva maneuver with sonotubometry improved specificity for ears without active opening on IDT (from 68% to 80%; p = 0.023). In several ears, the Valsalva maneuver detected active opening that was missed by sonotubometry or IDT.

When assessable, the Valsalva maneuver serves as a specific qualitative tool for evaluating ET passage and provides complementary information for assessing active ET opening when sonotubometry is inconclusive. Its limited quantitative accuracy and the frequency of unassessable results should be considered. This ROC-derived sonotubometry threshold may support future standardization and device development.