1. Choanal atresia Brian Wells, MPH, MSM St. George’s University
Presentation available online at:

2. Preface to Presented Research
"There is increasing concern that most current published research findings are false. The probability that a research claim is true may depend on study power and bias, the number of other studies on the same question, and, importantly, the ratio of true to no relationships among the relationships probed in each scientific field."
Ioannidis JPA (2005) Why most published research findings are false. PLoS Med 2(8): e124.

3. Historical Background
In 1755, Roederer first described congenital choanal atresia; therefore, this condition has been recognized for more than 200 years.
In 1854, Emmert reported the first successful surgical procedure for congenital choanal atresia in a 7-year-old boy using a curved trocar transnasally.
Over the years, the necessity of serial dilatations to maintain patency of the choanae has been clearly recognized.

4. Condition Overview
Is obliteration or blockage of the posterior nasal aperture
Often associated with bony abnormalities of pterygoid plates and mid-facial growth abnormalities

5. Etiology
The nasal cavities extend posteriorly during development under the influence of the posteriorly directed fusion of the palatal processes.
Thinning of the membrane occurs, which separates the nasal cavities from the oral cavity.
By the 38th day of development, the 2-layer membrane consisting of nasal and oral epithelia ruptures and forms the choanae (posterior nares).
Failure of this rupture results in choanal atresia. Although these choanae are not in the same location as the definitive choanae, which are eventually located more posteriorly, the unexpectedly anterior extent of choanal atresia is explained.
In 2008, Barbero et al suggested that prenatal use of antithyroid (methimazole, carbimazole) medications was linked to choanal atresia.

7. Anatomy Boundaries of the atresia plate Superior: sphenoid
Lateral: medial pterygoid lamina
Medial: vomer
Inferior: horizontal portion of the palatal bone

8. Nasopharyngeal Obstruction DDx
Some causes in the newborn
Apert syndrome
Choanal atresia
Craniofacial anomalies
Crouzon syndrome
Macroglossia
Pierre Robin syndrome
Traumatic deviated nasal septum

9. Epidemiology Occurs in ~1 in 5,000 – 7,000 live births
More common in girls than boys
Approximately 2 out of 3 cases are unilateral
More commonly right-sided
Slightly increased risk exists in twins.
Maternal age or parity does not increase the frequency of occurrence.
Chromosomal anomalies are found in 6% of infants with choanal atresia. Five percent of patients have monogenic syndromes or conditions.
Choanal atresia occurs with equal frequency in people of all races.

10. Presentation Bilateral – cyclic cyanosis relieved by crying
Varies depending on whether one or both sides are involved
Those with unilateral choanal atresia typically present later in life with
unilateral nasal discharge
And/or obstruction
Bilateral – cyclic cyanosis relieved by crying
Unilateral – chronic nasal obstruction, thick tenacious mucus

12. When to suspect?
If a #5 or #6 French catheter cannot be passed from the nose to oropharynx a distance of at least 32 mm
Qualitative measures of nasal airflow, such as the movement of a wisp of cotton under the nostrils or fogging of a mirror adds support to the clinical diagnosis

14. Diagnosis Confirmation
Confirmed with CT with intranasal contrast that shows narrowing of the posterior nasal cavity at the level of the pterygoid plate

15. CT Scan Evaluation
Choanal airspace measurement: mean normal is 0.67cm. Mixed atresia is 1/3 of normal, bony atresia measures 0.
Vomer width – Mean 0.23cm, bony atresia mean 0.6cm, membranous atresia 0.3 cm.

16. Associated abnormalities
May occur in isolation
May be part of a multiple congenital anomaly syndrome
Treacher-Collins, CHARGE, Kallman, VATER association
(C)oloboma of the eye, (C)NS abnormalities, (H)eart defects, (A)tresia of the choanae, (R)etardation of growth or development, (G)enital or urinary defects, (E)ar anomalies and/or deafness
(V)ertebral anomalies, (A)nal atresia, (C)ardiovascular anomalies, (T)racheoesophageal fistula, (E)sophageal atresia, (R)enal and/or radial anomalies, (L)imb defects
Other congenital abnormalities are present in 50% to 60% of individuals with unilateral and bilateral choanal atresia, respectively

17. Ancillary Services
In addition to a through physical exam, cardiology and ophthalmology consults are indicated
Associated anomalies include
Facial, nasal, or palatal deformities
Polydactylism
Congenital heart disease
Coloboma of the iris and retina
Intellectual disability
Malformations of the external ear
Esophageal atresia
Craniosynostosis
Tracheoesophageal fistula
Meningocele

18. Management
Immediate management of infants with choanal atresia includes placement of an oral airway and initiation of gavage feedings
Surgery indicated when conservative management is ineffective in sustaining adequate respiration and nutrition.
Definitive repair involves transnasal puncture and stenting or endoscopic resection of the posterior nasal septum through a transnasal approach with or without stenting
Transnasal puncture not favored due to high rate of recurrence
Classic, transpalatal approach is reserved for difficult or recurrent cases
Recurrent stenosis may occur even after successful surgery

19. Thank you! Presentation available for download at: http://d.pr/YYYj