Anatomical Relationships between Eustachian Tube and Internal Carotid Artery Using Computed Tomography

Jung, Jae Hoon; Goh, Eui Kyung; Lee, Il Woo; Jung, Jae Hwan; Oh, Se Joon; Kong, Soo Keun

Abstract

BACKGROUND AND OBJECTIVES
It is important to figure out the location between the internal carotid artery (ICA) and the Eustachian tube (ET) for conducting safe ET surgery. Using computed tomography (CT), this study was aimed to evaluate the anatomical relationship between ET and ICA according to age and gender.
SUBJECTS AND METHOD
Contrast enhanced CT scans of the paranasal sinus taken between January 2005 and December 2010 were reviewed retrospectively. A total of 216 patients (432 ears) were enrolled. In each patient, we measuresed the distance from the anterior cushion of torus tubarius to ICA (AC-ICA), the distance from the posterior cushion of torus tubarius to ICA (PC-ICA), the distance from the Rosenmuller fossa to ICA, the shortest distance from ET lumen to ICA (ET-ICA), and the angle between the imaginary lines from the orifice of ET to the posterior end point of nasal septum to point ICA (ET-NS-ICA). Patients were divided into 10 groups based on age difference of 15-years.
RESULTS
For the female patients aged 65 to 80 years old, AC-ICA, PC-ICA were closest from the nasopharynx. For this group, at p<0.05, the distances of AC-ICA, PC-ICA and ET-ICA showed a negative correlation with increasing age, whereasET-NS-ICA (p<0.05) showed a positive correlation, indicating a tendency of medicalization with increased age.
CONCLUSION
The distance between ET and ICA represents a variety of distribution according to gender and age. When performing a surgery for the nasopharyngeal portion of ET, the surgeon should be aware of the location of ICA in the preoperative CT findings.