Width of Patulous Eustachian Tube: Comparison of Assessment by Sonotubometry and Tubo-tympano-aerography

Ryokichi Ikeda, Tetsuaki Kawase, Iori Takata, Yoko Suzuki, Takeshi Sato, Yukio Katori, Toshimitsu Kobayashi

Research output: Contribution to journalArticlepeer-review

12 Citations (Scopus)


Objective: To assess the accuracy of tubo-tympano-aerodynamic- graphy (TTAG) in the estimation of morphological severity of patulous Eustachian tube (PET), and to compare the results with that of sonotubometry in clinical cases and in model experiments. Study Design: Retrospective chart review and model experiment. Setting: Tertiary referral center. Subjects: A retrospective survey of medical records in Sen- En Rifu Hospital identified 26 patients (12 men and 14 women subjects aged 14-78 yr, average 49.4_20.9 yr), comprising of 35 ears with PET. A definite diagnosis of PET was made for all patients based on the diagnostic criteria proposed by the Japan Otological Society. Main Outcome Measures: Commercial equipment for sonotubometry and TTAG (JK-05A; RION Co., Ltd., Kokubunji, Tokyo, Japan) were used in the following investigations. Model Experiment: The ET model was made using two truncated syringes with silicone barrels and a narrow connecting tube (0.2, 0.4, 0.58, 0.8, 1.00, 2.00, and 3.00 mm). Clinical Investigation: Morphological evaluation of ET patency was performed by a three-dimensional (3-D) CT (3D Accuitomo; Morita MFG. Corp., Kyoto, Japan) and analyzed by software (Integrated Information System i-VIEW; Morita MFG. Corp.). Results: The transmitted sound pressure level gradually increased as the tube caliber was widened up to 3mm diameter. On the other hand, pressure transmission was suddenly elevated and reached a plateau at 0.58mm in diameter. The cross-sectional area at the narrowest portion of the ET was significantly correlated with the sound attenuation from nostril to external auditory canal (EAC) (Spearman rank correlation test: R= -0.521, p<0.001). In contrast, the cross-sectional area at the narrowest portion of the ET was not correlated with the pressure changes of TTAG (Spearman rank correlation test: R=0.317, p=0.64). Conclusion: Sound transmission assessed by sonotubometry could be more useful than pressure transmission assessed by TTAG to predict the morphological severity of PET.

Original languageEnglish
Pages (from-to)E386-E392
JournalOtology and Neurotology
Issue number4
Publication statusPublished - 2019 Apr 1


  • Middle ear pressure
  • Patulous Eustachian tube
  • Sonotubometry
  • Three-dimensional (3-D) computed tomography

ASJC Scopus subject areas

  • Otorhinolaryngology
  • Sensory Systems
  • Clinical Neurology


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