CHOANAL atresia is an obstruction between the posterior nares (choana) and the pharynx. It may be unilateral or bilateral, complete or incomplete. When the atresia is bilateral and complete, any circumstance interfering with the entrance of air into the oropharynx will produce the symptoms of anoxia—irregular, rapid respiration and cyanosis. This occurs when the mouth is closed, when the infant is relaxed, as in sleep, during sucking, or with manual closing of the mouth. Crying opens the oropharynx, air enters the lung, and symptoms of respiratory embarassment clear. The impelling instinct for nasal respiration causes these recurring cycles.
In the newborn because of the presence of the cyanosis and dyspnea the condition may frequently be misdiagnosed as asphyxia neonatorum. It may be easily missed at autopsy examination of newborn infants unless pathologists routinely verify patency of the nares.
Congenital choanal atresia is rather rare. It was first reported by Otto,
COHEN HJ, WITCHELL IS. BILATERAL CONGENITAL CHOANAL ATRESIA IN NEWBORN. AMA Am J Dis Child. 1952;83(3):328-332. doi:10.1001/archpedi.1952.02040070074009