Enlargement of Eustachian Tube Lumen in Patulous Eustachian Tube Patients Compared to that by Aging.

Abstract

To evaluate the Eustachian tube (ET) dimensions in patulous ET (PET) patients compared with that by aging using sitting 3D computed tomography (CT). Retrospective study. Tertiary referral center. A retrospective survey of medical records in Sen-En Rifu Hospital identified 105 ears of 76 PET patients and 65 ears of 34 patients without ET dysfunction findings (non-PET). Subjects in both PET and non-PET groups were then divided into two age groups. Groups A and C defined as non-PET and PET subjects respectively, who were under the age of 60 years, while Groups B and D defined of non-PET and PET subjects respectively, who were 60 years and above. 3D CT (Accuitomo; Morita, Kyoto, Japan) was performed on all subjects in the sitting position. The ET lumen from the ET pharyngeal orifice to 15 mm was analyzed. No significant difference in the ET lumen near the pharyngeal orifice was found between Group A and C; however, there was a significant difference in the ET at points lateral to the pharyngeal orifice. The ET lumen was significantly larger at the site close to the pharyngeal orifice in Group B as compared to that of Group A. For the two groups of PET classified according to the size of the pharyngeal orifice and area close to the isthmus, age was only significantly different between two groups of pharyngeal orifice. On the contrary, sonotumometry and Ohta method were significantly different between the two groups of the area close to the isthmus. The lumen of the ET is enlarged in both PET and aging. However, the responsible site was found to be different. While the enlargement of the ET lumen in 60 years and above subjects without PET mainly occurred near the pharyngeal orifice of the ET, it was near the isthmus in under 60 years PET patients. Further study of possible clinical implications of these findings as well as treatment strategy are required.