External auditory canal atresia

Last revised by Mostafa El-Feky on 22 Dec 2021

External auditory canal atresia, also known as congenital aural atresia, is characterized by complete or incomplete bony atresia of the external auditory canal (EAC), often in association with a dysplastic auricle and an abnormal middle ear cavity or ossicles.

The incidence is 1 in 10,000-20,000 births 2.

Abnormal appearance of the external ear and conductive hearing loss present from birth.

Bilateral involvement is seen in approximately one-third of patients 2. The external auditory canal may be completely absent or incompletely atretic with further narrowing contributed to by soft tissue bands.

Findings in the middle ear are variable. The inner ear and inner auditory canal are typically normal (due to forming earlier in gestation). 

EAC atresia may be complicated by congenital cholesteatoma formation behind the atresia plate or in the middle ear.

Although frequently isolated (in which case the abnormality is less severe and isolated to the EAC) a number of syndromes are associated with external auditory canal atresia 2:

High resolution bony CT reformats is the modality of choice for assessing the external acoustic canal. A number or key points should be looked for and specifically mentioned in reports as it impacts on surgical reconstruction.

Surgical reconstruction requires formation of a new EAC and new tympanic membrane (usually with temporalis fascia). The ossicles often need to be mobilized.

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Cases and figures

  • Case 1: right
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  • Case 2: left (axial)
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  • Case 2: left (coronal)
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  • Case 3
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  • Case 4: right
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  • Case 5: right
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  • Case 6
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  • Case 7: left side
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