A Novel Eustachian Tube Test: Preliminary Research of Sonotubometry With Nasopharynx Under Pressure.

Abstract

The aim of this study was to develop a novel Eustachian tube (ET) test consisting of sonotubometry with nasopharynx under pressure to measure opening of the ET. We assessed the advantages of this novel approach compared with those of sonotubometry only or tubomanometry only and explored the possibility of quantifying ET patency. This was a prospective clinical study at a tertiary referral center. Sonotubometry, tubomanometry, and sonotubometry with nasopharynx under pressure were performed on a total of 106 ears. The ET-opening detection rates of the different test methods were compared with McNemar's test or Fisher's exact test. The correlation between the ET-opening latency index (R value) and nasopharyngeal pressure, as well as the correlation between the sound pressure of the external ear canal and the nasopharyngeal pressure, was assessed via Spearman's correlation coefficients. ET openings were detected most frequently during sonotubometry with nasopharynx under pressure, with opening rates of 93.40, 98.10, and 98.10% at 30, 40, and 50 mbar, respectively, which were significantly higher than those of sonotubometry (80.20%) and tubomanometry (74.50, 86.80, and 90.60% at 30, 40, and 50 mbar, respectively). Both R values and sound pressures were significantly different at pressures of 30, 40, and 50 mbar; the R value decreased with the increase of nasopharyngeal pressure (r = -0.298, p = 0.000), while the sound pressure increased with nasopharyngeal pressure (r = 0.251, p = 0.000). Sonotubometry with nasopharynx under pressure represents a novel hybrid ET test that our findings suggest is superior to sonotubometry only and tubomanometry only in detecting ET openings in healthy ears. Sound pressure resulting from sonotubometry with nasopharynx under pressure may be useful for quantifying the degree of openness of the ET. However, further validation in both healthy subjects and patients with ET dysfunction is required before this novel ET test may be recommended for clinical use.