• Clinical science

Choanal atresia

Abstract

Choanal atresia is a congenital condition characterized by a bony and/or membranous obstruction of the posterior nasal passage. This obstruction may occur either unilaterally or bilaterally. Unilateral choanal atresia often presents late with chronic inflammation (e.g., rhinorrhea, congestion) of the affected nasal passage. Bilateral choanal atresia manifests as obstructed nasal breathing with intermittent cyanosis immediately after birth; breathing improves when crying, as it allows the infant to breathe through his or her mouth. The diagnosis is confirmed with contrast rhinography or CT imaging. The definitive treatment is surgery, in which the obstructive membrane or bony portion is perforated.

Definition

  • Congenital condition characterized by a bony (90% of cases) and/or membranous (10%) obstruction of the posterior nasal passage

Epidemiology

  • Sex: > (∼ 2:1)
  • Unilateral choanal atresia is twice as common as bilateral choanal atresia.
  • Frequently associated with other anomalies (“CHARGE syndrome” - coloboma, heart defects, atresia choanae (also known as choanal atresia), retardation of growth, genital abnormalities, and ear abnormalities)

References:[1]

Epidemiological data refers to the US, unless otherwise specified.

Etiology

Choanal atresia has a positive association with periconceptional maternal exposure to:

Pathophysiology

  • It has been hypothesized that the condition is due to:
    • Failed resorption of the oronasal membrane during the embryonic period
    • Outgrowth of the palatine bone
    • Atypical mesodermal adhesions
    • Altered local growth factors

Clinical features

  • Bilateral choanal atresia
    • Early presentation
    • Infants are only able to breathe through the mouth (immediately postpartum)
    • Cyanosis that worsens when feeding and improves when crying
    • Upper airway obstruction (e.g., noisy breathing, dyspnea)
    • Food intake impossible: Complete airway obstruction is a life-threatening condition immediately following birth because of the worsening dyspnea associated with feeding.
  • Unilateral choanal atresia
    • Typically presents later in life
    • Chronic rhinitis in the affected nasal passage with purulent nasal discharge over several weeks

Diagnostics

  • The inability to pass the catheter through the nasal cavity is an indication of choanal atresia.
  • Confirmatory tests: Contrast rhinography in the supine position or CT scan
    • Unilateral or bilateral narrowing of the posterior nasal passage
    • Airway width < 3 mm

References:[2][3][4][1]

Treatment

  • Bilateral choanal atresia
  • Unilateral choanal atresia
    • Observation; and subsequent surgery when the infant is 1–2 years old

In suspected cases of bilateral choanal atresia, do not feed! A feeding tube is required due to the increased risk of aspiration!
References:[5][6]

Prognosis

  • With appropriate management, full recovery occurs in most cases.
  • Periodic dilatations may be needed, as stenosis can recur postoperatively.