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 recognized female predilection. The incidence is estimated at ~1:5000-8000.

Clinical presentation

Presentation depends on whether it is uni- or bilateral. Unilateral choanal atresia presents late and can be asymptomatic or present with rhinorrhea. Bilateral atresia can present with neonatal respiratory distress as infants are obligate nose breathers. Another finding is failure to pass a nasogastric tube.

Approximately two-thirds of cases are unilateral .


Structurally there are two main types:

  • osseous: ~90%
  • membranous: ~10%

Syndromic associations include

Other associations include

General pathogenesis includes

Radiographic features


Assessment with axial CT 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 above the obstruction point
  • thickening of the vomer
  • medial bowing of posterior maxillary sinus

Treatment and prognosis

Options include:

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

Differential diagnosis

On an axial CT scan consider:

Siehe auch:
und weiter: