[Anatomy and function of the Eustachian tube influence the development of chronic suppurative otitis media]

Objective:To explore the influence of anatomy and function of the Eustachian tube（ET） on the development of chronic suppurative otitis media. Method:We retrospectively enrolled 92 cases（184 ears） of adult patients with chronic suppurative otitis media（CSOM）, in whom 118 CSOM ears, 25 atelectasis ears and 41 normal ears were included. All patients underwent endoscopy, tympanometry, pure tone average, temporal bone computerized tomography scans and ET function test. Patients with pars flaccida retraction, cholesteatoma, ET obstruction or maxillofacial deformity were excluded. The length, angle and function of ET were analyzed. Result:The ET angle was （23.1±2.4） ° in CSOM ears, was （22.9±2.9） ° in atelectasis ears and was （25.1±3.0） ° in normal ears. The ETs were more horizontal in ears with CSOM and atelectasis（P<0.01）. The ET length was （39.2±4.3） mm in CSOM ears, was （41.7±5.8） mm in atelectasis ears and was （43.0±5.9） mm in normal ears. The ETs in CSOM ears were shorter compared to the ETs normal ears（P<0.01）. No significant difference was detected between the length of ETs of atelectasis ears and normal ears（P>0.05）. The ET dysfunction rate was 62% in CSOM ears, was 68% in atelectasis ears, which were both significantly higher than the dysfunction rate in normal ears（22%）（P<0.05）. Conclusion:The anatomical and functional changes of ETs contribute to the development of CSOM. For patients with more horizontal and shorter ETs as well as ETs dysfunction, more progressive treatment should be considered.