Eustachian Tube Dysfunction

Failure of the Eustachian tube to perform its three functions of middle ear ventilation and pressure equalisation, clearance of secretions, and protection from nasopharyngeal reflux and sound.

Functional anatomy

The tube is 31 to 38 mm long in the adult, with a lateral third that is bony and permanently open into the middle ear and a medial two thirds that is cartilaginous and normally closed at rest, opening intermittently on swallowing and yawning.

Tensor veli palatini, supplied by the mandibular nerve, is the principal dilator; levator veli palatini and salpingopharyngeus contribute.

In the infant the tube is shorter, wider and near horizontal at around 10 degrees, reaching the adult angle of 45 degrees by about 7 years, which explains the childhood pattern of middle ear disease.

Classification, which determines treatment entirely

• Obstructive or dilatory dysfunction: the tube fails to open. Causes are mucosal inflammation from allergic rhinitis, rhinosinusitis and reflux, adenoid hypertrophy, nasopharyngeal mass, cleft palate and submucous cleft with tensor veli palatini dysfunction, radiotherapy fibrosis, and craniofacial anomalies including Down syndrome.
• Baro challenge induced dysfunction: normal function at rest with failure to equalise during rapid ambient pressure change in flying and diving.
• Patulous Eustachian tube: the tube is abnormally open at rest. Causes include weight loss, pregnancy, oestrogen therapy, radiotherapy, neuromuscular disease, chronic nasal decongestant use and dehydration. It is frequently misdiagnosed as obstruction and treated with decongestants and grommets, which makes it worse.

Consequences of untreated obstructive dysfunction

Persistent negative middle ear pressure causes retraction, effusion, atelectasis, retraction pocket formation, ossicular erosion and cholesteatoma. This progression is the reason the condition matters beyond symptom relief.

Obstructive dysfunction

• Aural fullness and pressure, the dominant complaint.
• Muffled hearing, fluctuating and often worse with upper respiratory infection or altitude change.
• Popping, crackling and clicking sounds.
• Otalgia, particularly on descent in an aircraft.
• Tinnitus and mild unsteadiness.
• Symptoms improve transiently on swallowing, yawning or Valsalva.
• Otoscopy: retracted drum with a prominent lateral process of the malleus and foreshortened handle, reduced mobility, effusion or air fluid levels, and in advanced cases atelectasis or a retraction pocket.

Patulous tube

• Autophony of the patient's own voice, which is the cardinal symptom and is described as hearing oneself in a barrel.
• Autophony of breathing, synchronous with respiration, which is essentially pathognomonic.
• Aural fullness that is relieved by lying down, by putting the head between the knees, or during an upper respiratory infection, because venous engorgement closes the tube. Relief on lying down is the key discriminator from obstructive dysfunction.
• Otoscopy: a lateral to medial excursion of the tympanic membrane synchronous with respiration, best seen with the patient breathing forcefully through one nostril with the other occluded.

Red flags

• Unilateral effusion or dysfunction in an adult, requiring nasoendoscopy to exclude nasopharyngeal carcinoma. This is not negotiable, particularly in patients of southern Chinese, Southeast Asian and North African descent.
• Cranial neuropathy, neck node, epistaxis or nasal obstruction alongside a unilateral effusion.
• Progressive retraction pocket with keratin, indicating developing cholesteatoma.

• Otoscopy and pneumatic otoscopy, assessing drum position, mobility and retraction pocket depth.
• Tympanometry: type C with markedly negative pressure below minus 100 daPa indicates obstruction; type B with normal volume indicates effusion. In patulous tube, the tympanogram shows fluctuation of the trace synchronous with respiration.
• Pure tone audiometry with bone conduction, documenting the conductive component.
• Valsalva and Toynbee manoeuvres with tympanometry before and after, demonstrating whether pressure can be equalised.
• Nasoendoscopy in every adult with unilateral disease and in all persistent cases, examining the fossa of Rosenmüller, the tubal orifice, the adenoid pad and the postnasal space, with biopsy of anything suspicious.
• The Eustachian Tube Dysfunction Questionnaire, a seven item instrument scored 1 to 7 per item, with a mean item score above 2.1 indicating dysfunction. It is useful for selecting patients for balloon dilation and for measuring response.
• Tubomanometry and sonotubometry where available, giving objective assessment of tubal opening.
• Computed tomography of the temporal bone and nasopharynx where cholesteatoma, a mass or a bony abnormality is suspected.
• Magnetic resonance imaging for suspected nasopharyngeal malignancy or skull base disease.

Treatment depends absolutely on which type is present. Treating a patulous tube as obstruction, and vice versa, is the commonest error.

Obstructive dysfunction, medical management

• Treat the underlying nasal disease, which is where most of the benefit lies.
• Intranasal corticosteroid for allergic rhinitis and rhinosinusitis: mometasone furoate 100 micrograms per nostril once daily, or fluticasone furoate 55 micrograms per nostril once daily, for at least 6 to 8 weeks. Teach correct technique with the spray directed laterally away from the septum, since poor technique is the usual reason for failure. Intranasal steroids do not treat Eustachian dysfunction directly, and their benefit comes from treating the nasal inflammation.
• Antihistamine where allergy is confirmed: cetirizine 10 mg daily or loratadine 10 mg daily in adults.
• Nasal saline irrigation.
• Treat reflux where laryngopharyngeal reflux is present, with a proton pump inhibitor such as omeprazole 20 mg twice daily 30 minutes before meals for 8 to 12 weeks, and lifestyle modification.
• Topical decongestants such as xylometazoline 0.1 percent are useful for a maximum of 5 days for acute barotrauma prevention, and cause rhinitis medicamentosa beyond that.
• Autoinflation with a nasal balloon, performed three times daily, which has modest evidence in children with effusion and is a reasonable first line self management measure.
• Politzerisation in the clinic.
• Antihistamines and decongestants do not improve chronic dysfunction and should not be prescribed long term.

Obstructive dysfunction, procedural management

• Ventilation tube insertion is the definitive symptomatic treatment. It bypasses the tube rather than correcting it, and provides reliable relief of fullness and hearing loss. Anticipate otorrhoea, water precautions issues and a small risk of persistent perforation.
• Balloon Eustachian tuboplasty: a balloon catheter passed transnasally into the cartilaginous portion and inflated to 10 atmospheres for 2 minutes, remodelling the cartilaginous lumen and reducing submucosal inflammation. Indicated for persistent obstructive dysfunction with an abnormal tympanogram and a raised questionnaire score, after at least 6 to 12 weeks of failed medical therapy, and in baro challenge dysfunction. It is contraindicated in patulous tube, in patients with a nasopharyngeal mass, and where the dysfunction is due to a craniofacial or neuromuscular cause. Carotid injury is a theoretical risk given the proximity of the internal carotid artery to the tubal cartilage, and subcutaneous emphysema occurs occasionally.
• Adenoidectomy where adenoid hypertrophy or chronic adenoiditis contributes, particularly in children over 4 years and those requiring repeat tube insertion.
• Address nasal obstruction with septoplasty and turbinate reduction where relevant.

Patulous Eustachian tube

• Reassure and explain, since patients are often distressed and have been told the ear is normal.
• Weight restoration where weight loss precipitated it.
• Adequate hydration.
• Stop topical and systemic decongestants.
• Nasal saline, and preparations that promote mucosal oedema such as potassium iodide, or oestrogen or benzyl alcohol nasal drops in refractory cases.
• Avoid grommets, which usually worsen autophony by removing the drum's damping effect, though a small tube occasionally helps by altering middle ear compliance.
• Surgical options in severe refractory cases: injection of filler around the tubal orifice, cartilage or fascia plugging of the tube, and patulous Eustachian tube reconstruction with a shim. Reserve these for disabling symptoms, and counsel that overcorrection produces obstructive dysfunction.

Baro challenge dysfunction

• Prophylactic topical decongestant 30 minutes before descent, together with an oral decongestant such as pseudoephedrine 60 mg 30 minutes before flying where not contraindicated by hypertension, ischaemic heart disease or arrhythmia.
• Frequent swallowing, chewing and gentle Valsalva during descent, and pressure equalising earplugs.
• Avoid flying and diving with an active upper respiratory infection.
• Balloon dilation or ventilation tubes for professionals who cannot avoid pressure change, such as aircrew and divers, noting that a ventilation tube contraindicates diving.

Follow up

Reassess symptoms, tympanometry and audiometry at 6 to 12 weeks. Persistent retraction requires surveillance for pocket formation and cholesteatoma, with microscopic examination at 6 monthly intervals and surgical intervention if the pocket deepens or accumulates keratin.