Choanal atresia

Choanal atresia is associated with a higher risk of other airway problems, including:

• tracheomalacia.[1]
• laryngomalacia.[1]
• subglottic stenosis.[1]

Sometimes, babies born with choanal atresia also have other abnormalities:

• coloboma.[1]
• heart defects and cardiovascular disease.[1]
• intellectual disability.[1]
• growth impairment.[1]
• genital hypoplasia.[1]
• CHARGE syndrome.[1]
• others.

Also any condition that causes significant depression of the nasal bridge or midface retraction can be associated with choanal atresia. Examples include the craniosynostosis syndromes such as Crouzon syndrome,[1] Pfeiffer syndrome,[1] Treacher Collins syndrome,[1] Apert syndrome,[1] and Antley-Bixler syndrome.

Very few risk factors for choanal atresia have been identified. In general, choanal atresia is associated with a higher risk of other birth defects.[1] Bilateral choanal atresia is more associated than unilateral choanal atresia.[1]

While causes are unknown, both genetic and environmental triggers are suspected.[3] One study suggests that chemicals that act as endocrine disrupters may put an unborn infant at risk. A 2012 epidemiological study looked at atrazine, a commonly used herbicide in the U.S., and found that women who lived in counties in Texas with the highest levels of this chemical being used to treat agricultural crops were 80 times more likely to give birth to infants with choanal atresia or stenosis compared to women who lived in the counties with the lowest levels.[4] Another epidemiological report in 2010 found even higher associations between increased incidents of choanal atresia and exposure to second-hand-smoke, coffee consumption, high maternal zinc and B-12 intake and exposure to anti-infective urinary tract medications.[5] The anti-thyroid medication methimazole has been associated with the development of choanal atresia in rare cases if given during the first trimester of pregnancy.

Choanal atresia can be suspected if it is impossible to insert a nasal catheter.[2] The length of catheter that can be inserted indicates where choanal atresia has occurred: shorter distances indicate a problem with the vomer, while longer distances indicate a problem with the posterior choanae.[1] Mucus can be cleared (using suction) to visualise the abnormality.[1]

Diagnosis is confirmed using CT scan.[1][2] This is also useful for differential diagnosis.[1]

As bilateral choanal atresia is an emergency, the airway is secured. A small tube may be placed to the laryngopharynx.[1] Tracheal intubation can also be used.[1] If surgery cannot be performed soon after birth, tracheostomy may have better outcomes.[1]

Surgery may be used to reopen the airway,[6] particularly with bilateral choanal atresia.[1] This may be approaches through the nasal cavity or through the palate (accessed through the mouth).[6] A stent may be inserted to keep the newly formed airway patent.[7] Repeated dilatation may be performed.[8] CT guidance may be used.[6]