Choanal atresia

Choanal atresia refers to a lack of formation of the choanal openings. It can be unilateral or bilateral.

It frequently presents in neonates where it is one of the commonest causes of nasal obstruction in this age group. There is a recognised female predilection. The incidence is estimated at ~1:5000-8000.

Depends on whether it is uni or bilateral. Unilateral choanal atresias present late and can be asymptomatic or present with rhinorrhoea while bilateral atresias can present with neonatal respiratory distress (infants are obligate nose breathers). Another finding is failure to pass a nasogastric tube.

Approximately two-thirds of cases are unilateral 6-7.

Structurally there are two main types:

  • osseous: ~90% 2
  • membraneous: ~10%

Syndromic associations include

Other associations include

General pathogenesis includes


Axial CT scans are best as assessment:

  • may show a uni or bilateral posterior nasal narrowing with an obstruction
  • airway less than 3 mm
    • measurement done at the reference level of the pterygoid plates in the axial plane
  • an air-fluid level may be present above the obstruction point
  • may show thickening of the vomer
  • medial bowing of posterior maxillary sinus

Options include:

  • endoscopic perforation (for membranous types)
  • full choanal reconstruction

On an axial CT scan consider:

Share article

Article information

rID: 9647
Section: Pathology
Synonyms or Alternate Spellings:
  • Atresia of the choanae
  • Choanal atresias

Support Radiopaedia and see fewer ads

Cases and figures

  • Drag
    Case 1: membranous
    Drag here to reorder.
  • Drag
    Case 2
    Drag here to reorder.
  • Drag
    Case 3: bilateral and osseous
    Drag here to reorder.
  • Drag
    Case 4: unilateral and osseous
    Drag here to reorder.
  • Drag
    Case 5: bilateral membranous
    Drag here to reorder.
  • Drag
    Case 6: bilateral osseous
    Drag here to reorder.
  • Drag
    Case 7: unilateral - right
    Drag here to reorder.
  • Drag
    Case 8: unilateral osseous
    Drag here to reorder.
  • Updating… Please wait.

    Alert accept

    Error Unable to process the form. Check for errors and try again.

    Alert accept Thank you for updating your details.