What is a Patulous Eustachian Tube?
A patulous Eustachian tube (PET) is a condition where the Eustachian tube—the slender passage connecting the back of the nose to the middle ear—remains abnormally open instead of staying closed at rest, causing distressing symptoms like autophony (hearing one's own voice), breathing sounds in the ear, and aural fullness 1, 2, 3.
Normal Eustachian Tube Function vs. Patulous State
Normally, the Eustachian tube should remain closed to seal off the middle ear from germs and mucus in the back of the nose 4. It opens briefly only when swallowing or yawning to equalize pressure and replace air naturally absorbed by the middle ear lining 5.
In PET, this protective mechanism fails—the tube stays open intermittently or continuously 6, 7. This creates a direct acoustic pathway between the nasopharynx and middle ear, allowing patients to hear their own breathing, voice, and sometimes even their heartbeat 1, 2.
Clinical Presentation
The hallmark symptoms of PET include:
- Autophony: Hearing one's own voice abnormally loud in the affected ear (present in 59.9-81.8% of cases) 8
- Breathing autophony: Hearing one's own breathing sounds (35.3-47.1% of cases) 1, 8
- Aural fullness: Sensation of blockage or pressure in the ear 1, 3
- Pulsatile tinnitus: Hearing one's heartbeat 2
- Hypernasality: In some cases, affecting speech quality 1
On examination, the tympanic membrane may appear atrophic and can visibly move with respiration, though this objective finding is not always present even in symptomatic patients 3.
Common Associations and Risk Factors
PET is frequently associated with peritubal atrophy and conditions causing tissue loss around the Eustachian tube 3, 9:
- Significant weight loss (including post-bariatric surgery) 2, 10
- Pregnancy or estrogen use (affects one-third of female patients) 3
- General tissue atrophy in the peritubal region 9
Interestingly, recent evidence suggests that while weight loss is associated with PET symptoms, the actual incidence of confirmed PET following bariatric surgery may be lower than historically reported when strict diagnostic criteria are applied 10.
Diagnostic Considerations
The Japan Otological Society established diagnostic criteria classifying cases as "definite PET" (both symptoms and objective findings present) or "possible PET" (either symptoms relieved by Eustachian tube-closing maneuvers OR objective findings present, but not both) 8.
Important clinical pearl: Patients with symptom relief from Eustachian tube-closing maneuvers but lacking objective findings (possible PET group A) have nearly 5-fold higher likelihood of progressing to definite PET compared to those with objective findings but no symptom relief (possible PET group B), who more often have alternative diagnoses like hearing loss 8.
Why "U-Shaped" Description?
While the provided evidence doesn't specifically address why PET might be described as "U-shaped," this likely refers to the anatomical configuration of the Eustachian tube itself, which curves from the middle ear downward and forward to the nasopharynx. In children, this tube is described as more horizontal, becoming longer, stiffer, and more vertical with growth 5, 4. The "U-shaped" descriptor may emphasize the curved anatomical pathway that remains pathologically open in PET.
Management Implications
PET is considered a benign but distressing condition 3, 9. Conservative management includes weight gain and mucus-producing agents, with various surgical options available for refractory cases 9, 7. The condition requires careful differentiation from obstructive Eustachian tube dysfunction, which presents with overlapping symptoms but requires opposite management strategies 7.