Learning Objectives: 1. Know the role of surfactants in normal Eustachian tube function 2. Know that there is reduction of surfactant in the nasopharyngeal ET in cases of OM 3. Learn the potential for using intranasal surfactant for the treatment of ETD and OM.
It has long been understood that endogenous surfactants play a significant role in the normal functionality of the Eustachian tube (ET) and that there is a reduction in surfactants at the nasopharynx (NP) and the nasopharyngeal end of the Eustachian tube in humans with secretory otitis media. The site of ET obstruction in chronic middle ear disease appears to be at the protympanic portion of the ET more so than at the NP cartilaginous portion, which is the portion affected by balloon Eustachian tuboplasty. Previous researches have used nebulized pulmonary surfactants and shown a trend or actual improvements in ET passive opening pressure in animal models. However, due to the physicochemical properties of surfactants, nebulizing them dramatically reduces their ability to ‘de-stick’ apposed mucosal surfaces. Additionally, animal-derived medical surfactants are expensive and pose potential risks. We have developed a fully synthetic surfactant delivered intranasally as an aerosol via a metered dose inhaler. In normal ears, our surfactant dramatically reduced passive opening pressure of the ET in mouse and gerbil models. In gerbils with otitis media with effusion, once-daily surfactant spray reduced days of effusion from 16 to 10; twice-daily surfactant spray and once-daily surfactant with steroid spray reduced it to 8 days; and twice-daily surfactant with steroid spray reduced it further to 6 days. There was no recurrence of effusion after stopping treatment. In chinchillas with acute bacterial otitis media, intranasal surfactant spray significantly reduced effusion, severity of disease and bacterial burden without concomitant administration of antibiotics. We postulate that our synthetic, dry powder, aerosolized surfactant spray when delivered intranasally in humans will ameliorate many cases of Eustachian tube dilatory dysfunction and a range of cases of otitis media. Clinical studies to evaluate surfactant effects in humans with middle ear disease are planned.