The eustachian tube serves to ventilate and equalize middle ear pressure; clear secretions from the middle ear with mucociliary action; and protect the middle ear from sounds, pathogens, and secretions from the nasopharynx. First described anatomically by Eustachius in 1563 and with its exact function worked out a century later, Valsalva realized in 1703 that its opening was dynamic, not static, and described the namesake maneuver to expel pus from the middle ear into the external auditory canal. By the mid 18th century, multiple authors had attempted Eustachian tube catheterization and by the early 19th century, catheterization with irrigation and air insufflation had been described.(1) This shows how Eustachian tube dilation has been a known treatment for centuries, despite its relative obscurity prior to this decade. ET dysfunction is a common diagnosis many patients receiving care from an otologist or otolaryngologist receive. Dysfunction can be broken down into dilatory, which is caused by inflammation such as a virus, baro-challenge induced such as in scuba divers or those taking flights and patulous, which is of unclear etiology.(2) Symptoms are thought to include but are not limited to ear fullness, the sensation that the ear is underwater, otalgia, muffled hearing, tinnitus, autophony and ear popping amongst others. Clear diagnostic criteria are not present, though it is generally felt that a combination of symptoms and objective findings on otoscopy or tympanogram are enough to support the diagnosis. Many have resorted to using the Eustachian Tube Dysfunction Questionnaire-7 which is a validated symptom driven assessment, although it is only moderately associated with objective measures of ET dysfunction. (3,4) The only population-based study looking at prevalence used otoscopy, tympanogram and audiometry to estimate that it affects 0.9% of adults.(5) Unfortunately, there is currently no gold standard for treatment of ET dysfunction.

The only randomized control study of medical treatments showed no impact of nasal steroids on ET dysfunction.(6) The most common surgical option is a tympanostomy tube, which has been used since the 1950s for both middle ear effusions and ET dysfunction.(7) Tympanostomy tubes can alleviate tympanic membrane retraction, atelectasis and effusion, although they do not address the underlying etiology of the ET dysfunction. Numerous nonrandomized and or noncontrolled studies have showed improvement in symptoms with tympanostomy tube placement. Depending on the study and the definition, 70-100% improvement has been reported. Despite this, high-level evidence for tympanostomy tube efficacy in ET dysfunction remains lacking.(8) Adenoidectomy has also been proposed as a way to improve ET function, but not surprisingly, most studies have shown that it only helps if the adenoids are found to be abutting or obstructing the torus tubarii.(9,10) Furthermore, these studies focus on children, and the adenoid pad is not likely to be a contributing factor in most adults. Eustachian tube balloon dilation recently came back into the mainstream beginning with the 2010 study by Ockermann et al. which showed the procedure was safe and produced good results in a small cohort. Numerous studies since then have shown efficacy, including two separate multicenter randomized controlled trials published in 2017 and 2018. Both of these showed statistically and clinically significant superiority of ET balloon dilation over control as measured by improvement in ETDQ-7 and tympanogram type at up to 1 year. (11,12,13)