Quantitative Eustachian Tube Function Testing in Patulous Eustachian Tube: Case-Control and JOS Subgroup Analyses

To evaluate objective Eustachian tube (ET) function test parameters measured using a comprehensive ET function test system in patulous ET (PET) ears versus controls and to examine subgroup differences using the Japan Otological Society (JOS) classification and symptom frequency.

We retrospectively analyzed objective ET function test results from adults evaluated for suspected PET (April 2025 to January 2026) and healthy controls. PET ears were classified according to the JOS criteria and stratified according to symptom frequency (persistent vs. intermittent). Key parameters were compared between the groups, and receiver operating characteristic (ROC) analysis was performed.

We analyzed 33 PET and 34 control ears. Probe-tone sound pressure level (SPL) (P=0.006), opening duration (P=0.022), tubotympanoaerodynamography (TTAG) opening pressure (P<0.001), and residual middle-ear volume (P<0.001) differed significantly between the PET and control ears, whereas external auditory canal SPL did not (P=0.976). Within the PET cohort, probe-tone SPL and TTAG opening pressure differed according to symptom frequency (persistent vs. intermittent) and JOS classification (definite vs. possible). ROC analysis showed discrimination for TTAG opening pressure (area under the curve, AUC=0.9565, P=0.0016) and probe-tone SPL (AUC=0.8187, P=0.0106).

Multiple objective ET function parameters differed between the PET and control ears. TTAG opening pressure and sonotubometry probe-tone SPL were consistently informative across clinical stratifications, supporting their practical role as quantitative adjuncts for structured PET assessments within the JOS framework.