Video Endoscopic Analysis of Eustachian Tube Function in Patients with Otitis Media with Effusion

Abstract

SUMMARY

ustachian tube dysfunction is a common problem. Dilatory dysfunction is one end of a spectrum of disorders of the Eustachian tube, the other end being the patulous dysfunction. Dilatory dysfunction can be broadly classified into obstructive (mainly mucosal inflammation or mass lesion) or dynamic (muscular) dysfunction. Dilatory Eustachian tube dysfunction is directly related to, and is an etiologic factor for the development of otitis media with effusion, along side with many other middle ear complications related to chronic negative middle ear pressure. Some patients have chronic dysfunction and its’ sequel of otitis media with effusion, in the absence of; or after control of a detectable etiology.

Many tools have been utilized to directly and indirectly measure the function of the Eustachian tube. Video endoscopy of the nasopharyngeal orifice of the Eustachian tube is a useful tool to aid diagnosis of the etiology of tubal dysfunction. Videos obtained from endoscopic examination can also be played in slow motion to further help in the analysis of the phases of Eustachian tube movement and detect the origin of the dysfunction; whether obstructive or muscular.

In this study we recruited 51 subjects; 25 patients suffering from otitis media with effusion, and compared them to 26 normal subjects. We used flexible nasopharyngeal endoscopy to obtain videos of the nasopharyngeal orifice of the Eustachian tube at rest, and during dynamic movement. Two blinded observers rated the videos, and scored the four parameters of opening of the Eustachian tube: the overall valve opening, the mucosal inflammation score, the LVP movement and the TVP movement.

The presence of otitis media with effusion is Eustachian tube is associated with decreased overall opening of the tubal valve. The results showed a clear side predilection in unilateral cases as all unilateral otitis media with effusion occurred on the left side. Mucosal inflammation is the main cause for Eustachian tube dysfunction, and significant correlation between presence of effusion and worse mucosal inflammation score was found. When looking at the muscular movement of the tube, there is no role for LVP dysfunction in the pathogenesis of otitis media with effusion. A significant correlation between TVP dysfunction and the development of middle ear effusion was not found by combining the data from both observers. Nevertheless, given the significant degree of TVP dysfunction reported by one of the observers, a role for tensor veli palatini muscle dysfunction in the pathogenesis of chronic Eustachian tube dysfunction cannot be completely ruled out. Further studies with larger number of subjects and more blinded observers are recommended. Worth mentioning that in some cases there might be some difficulty in commenting on TVP movement in the presence of severe mucosal edema and stiffening of the non-muscular soft tissue.

In conclusion, nasopharyngeal endoscopic evaluation of the Eustachian tube is recommended for all patients with otitis media with effusion, especially patients who fail medical treatment. Mucosal inflammation may still be present despite absence of nasal symptoms, or apparent adequate symptomatic control of inflammatory conditions of the nose and pharynx; that reflect on nasopharyngeal mucosal inflammation. Therefore, medical treatment of the mucosal inflammation remains the main stay of treatment of the dilatory dysfunction.