Histopathology of the Mucosa of Eustachian Tube Orifice at the Middle Ear in Chronic Otitis Media With Effusion: Possible Insight Into Tuboplasty Failure

Abstract

Introduction: Balloon dilation of the cartilaginous segment of the Eustachian tube has emerged as a means to directly augment tubal dilatory function, and this has been applied as a potential treatment for otitis media with effusion (OME). Although results of clinical studies involving this modality appear promising, there are still a moderate number of ears affected by OME that do not respond. The purpose of this study was to investigate the status of mucosa of the Eustachian tube at the middle ear orifice in OME as it may relate to some cases of tuboplasty failure. Methods: Twenty-three temporal bone specimens with OME were identified within an institutional archived collection. Each specimen was inspected for the presence of a fixed obstruction at the level of the Eustachian tube orifice at the protympanum. In addition, the mucosa at the tubal orifice was graded on a 4-point scale. Results: Overall, 3 cases (13%) were normal (Grade 1), 6 cases (26%) were mildly thickened (Grade 2), 11 (48%) were severely thickened (Grade 3), and 3 (13%) were severely thickened with polypoid degeneration (Grade 4). A single case was noted to have a complete fixed obstruction in the form of a mucosal web. Conclusion: In ears affected by OME, the mucosa of the Eustachian tubal orifice at the middle ear is most often severely thickened. Normal mucosa, mucosa with severe polypoid changes, or a complete fixed obstruction are possible but uncommon. The majority of specimens studied had sufficiently diseased mucosa to raise questions regarding whether thickened mucosa in the tubal orifice may act as a barrier to middle ear ventilation that would not be directly addressed by cartilaginous Eustachian tube balloon dilation.