3. INTRODUCTION
⢠The choanae are the posterior openings that connect the
nasal cavities with the nasopharynx.
⢠They develop between the third and seventh embryonic
weeks, following rupture of the vertical epithelial fold
between the olfactory groove and the roof of the primary
oral cavity (pronasal membrane)
6. DEFINITION
⢠Choanal atresia is defined as congenital stenosis of the
posterior nasal apertures.
⢠It is the absence of communication between the posterior
nasal cavity and the nasopharynx.
7. EPIDEMIOLOGY
⢠The incidence ranges from 1 in 5000 to 1 in 8000 live births.
⢠Up to two thirds of cases are unilateral, with atresia most
commonly occurring on the right side.
⢠Fifty percent of all patients with choanal atresia and up to
75% of patients with bilateral disease have other associated
congenital anomalies.
⢠Female to male ratio is 2:1
8. EPIDEMIOLOGY
⢠Slightly increased risk exists in twins.
⢠Approximately 2 out of 3 cases are unilateral
⢠More commonly right-sided
⢠Maternal age or parity does not increase the frequency of
occurrence.
⢠Chromosomal anomalies are found in 6% of infants with
choanal atresia.
⢠Choanal atresia occurs with equal frequency in people of all
races.
9. EPIDEMIOLOGY
⢠Bilateral atresia associated with other congenital anomalies
in 75% of cases
⢠â CHARGE, Crouzonâs, Treacher Collins
⢠â Polydactyly, craniosynostosis, cleft lip/palate,
⢠nasal/palatal deformities
10. AETIOLOGY
A)Embryogenesis
4 theories of etiology of atresia plate
1. Persistence of buccopharyngeal membrane from the
foregut
2. Abnormal persistence of the nasobuccal membrane
3. Abnormal location of mesoderm forming adhesions in the
choanal region
4. Misdirection of neural crest cell migration
⢠Current popular theory- Neural Crest
11. AETIOLOGY
⢠#2 was previously most popular theory; now itâs #4
⢠#4 supported by fact that Treacher Collins syndrome has a
high rate of choanal atresia and itâs a disease of abnormal
neural crest migration.
12. AETIOLOGY
⢠B)Prenatal/maternal
⢠use of antithyroid (methimazole, carbimazole) medications
was linked to choanal atresia.
⢠Intake in the highest quantity: Vitamin B-12, zinc, niacin
⢠Intake in the lowest quantity: Methionine, vitamin D
⢠Cigarette smoking
⢠Coffee (⼠3 cups per day)
13. TYPES
⢠There are two forms of choanal atresia,
⢠unilateral atresia.
⢠bilateral atresia
⢠Can also be classified as
-membranous atresia
-bony atresia.
14. Unilateral choanal atresia
⢠Unilateral choanal atresia is less threatening to a newborn
because the nasal passage is only blocked on one side.
⢠This allows an infant to breathe somewhat normally at birth,
but a mucus discharge is noticeable in the affected side of
the nose.
15. Bilateral choanal atresia
⢠Bilateral choanal atresia is a blockage of both sides of the
nasal passage.
⢠This is life threatening because the baby cannot breathe at
birth.
⢠Crying allows the child to breathe until the infant discovers
that it can breathe through itsâ mouth.
⢠A tube is placed in the childâs mouth and taped in place to
allow for air passage.
17. Associated abnormalities
⢠May occur in isolation , or
⢠May be part of a multiple congenital anomaly syndrome like,
CHARGE syndrome, Treacher Collins, and Crouzonâs disease
(75% of cases).
18. CHARGE syndrome
⢠Coloboma of the iris, choroid, and/or microphthalmia
⢠Heart defect such as atrial septal defect (ASD).
⢠Atresia of choanae
⢠Retarded growth and development
⢠Genitourinary abnormalities such as cryptorchidism,
microphallus, and/or hydronephrosis
⢠Ear defects with associated deafness
19. Clinical features
⢠BILATERAL
⢠Complete nasal obstruction
⢠Immediate respiratory distress
⢠Potential death due to asphyxia
⢠Cyclic respiratory obstruction
⢠Childâs cries opens the mouth and obstruction is relieved
20. Clinical features
⢠In some cases, this may present as cyanosis while the baby is
feeding, because the oral air passages are blocked by the
tongue, further restricting the airway.
⢠Symptoms of severe airway obstruction and cyclical cyanosis
are the classic signs
⢠The cyanosis may improve when the baby cries, as the oral
airway is used at this time
⢠These babies may require airway resuscitation soon after
birth
21. Clinical features
⢠UNILATERAL
⢠Sometimes, a unilateral choanal atresia is not detected until
much later in life because the baby manages to get along
with only one nostril available for breathing
⢠Rarely causes respiratory distress
⢠Mucoid discharge
23. Diagnosis
⢠Inability to pass catheter or NG tube
â 6 Fr
â 32 mm as proposed distance
⢠Absence of fogging of mirror under nose
⢠CT scan
⢠Nasal endoscopy to confirm
24. Diagnosis
⢠The lack of movement of a thin wisp of cotton under the
nostrils while the mouth is closed.
⢠Acoustic rhinometry
⢠Administering into the nose a colored solution that is visible
in the pharynx
26. INVESTIGATIONS
⢠CT scanning is the radiographic procedure of choice in the evaluation
of choanal atresia.
⢠For good results, careful suctioning is performed to clear excess
mucus, and a topical decongestant is applied.
⢠The purpose of CT scanning is outlined as follows:
⢠Confirm the diagnosis of choanal atresia (unilateral or bilateral).
⢠Evaluate choanal atresia
⢠Exclude other possible nasal sites of obstruction.
⢠Determine the degree of bony, membranous, or mixed atresia.
⢠Delineate abnormalities in the nasal cavity and nasopharynx.
29. MANAGEMENT
⢠The most crucial initial interventions in a child with bilateral
atresia should focus on stabilizing the patient.
⢠The goal is finding a way to oxygenate the patient despite
the crippling upper airway obstruction.
⢠For this purpose one may use a special nipple called a
McGovern nipple which has a large hole in its center for air
passage or a plastic oral airway piece.
30. MANAGEMENT
⢠Immediate management of infants with choanal atresia
includes placement of an oral airway and initiation of gavage
feedings
⢠Definitive repair involves transnasal puncture and stenting or
endoscopic resection of the posterior nasal septum through
a transnasal approach with or without stenting.
35. Transnasal Approach
⢠Endoscopic vs Microscope vs Blind Puncture
⢠Curved/straight urethral sounds- puncture
⢠May choose to puncture with dilation only
⢠Powered instruments (microdebrider, diamond burr drill)- open
choana
⢠Must direct the dissection inferomedially
⢠Preserving mucosal flaps
36. Transnasal Endoscopic Approach
1. Decongest the nose topically (oxymetazoline) and local
anesthesia injection with 1% lidocaine with epinephrine
into the borders of the atretic plate
2. Expose the palate and nasopharynx (may use mouth gag)
and visualize the atresia with a 120 degree endoscope from
below
3. Directing it inferomedially, use a spinal needle to puncture
through the plate and visualize it from below to confirm
proper position
Note: inferomedial placement is crucial to avoid
complications such as brain trauma
37. Transnasal Endoscopic Approach
⢠Create laterally based anterior mucosal flaps with sickle knife over
plate
⢠Mechanically open the atretic plate (drill or microdebrider) and
remove the thickened posterior vomer with a drill or backbiter
⢠Enlarge the new choana to the size of a 16 French catether/urethral
sound
⢠+/- stenting and/or Mitomycin C placement
40. Transpalatal approach
⢠For the transpalatal approach, first a mouth gag is inserted and then
local anesthesia applied into the palate.
⢠The greater palatine artery is the main supply for this operative area.
Next, typically a Ushaped palatal mucosal flap based on this artery is
made (must preserve).
⢠Once the mucosal flap is elevated, the involved bone creating the
atresia and the palatal bone anterior to the vessels is resected using a
drill or bone rongeur.
⢠Lastly, stents are put in placed, and the palatal flap is put back into
place which is used to resurface the mucosa.
43. Transpalatal- Complications
Why Itâs Not First line
⢠May stunt/alter palate growth
⢠Crossbite deformity- 52% chance
⢠Palate flap necrosis and fistula
⢠High rate of restenosis
Note: often recommend only in kids > 5yrs after most palatal
growth has finished.
45. Complications
⢠Stent complications: foreign body complications, alar erosions,
pressure necrosis from columella stitch
⢠Transpalatal approach: alter palatal growth
⢠Mucosal flap death
⢠Eustachian tube dysfunction: damage to tori
⢠Restenosis: if multiple endoscopic attempts failed, consider
transpalatal approach and adjuncts such as Mitomycin C
⢠CNS trauma: entrance to anterior cranial fossa with blind puncture
(rare).
47. Conclusion
⢠When faced with a neonate or other aged child with signs of
nasal/upper airway obstruction or respiratory distress, one
must consider the possibility of a unilateral or bilateral
choanal atresia.
⢠If choanal atresia is identified, it is necessary for the
physician to investigate other possible associated anomalies
such as those of CHARGE syndrome (3Câs of coloboma,
choanal atresia, semicircular canals absence).
⢠If bilateral atresia is found, this is considered an upper airway
emergency and the proper measures should be taken to
stabilize the patient first before considering surgical
intervention.
48. REFERENCES
⢠Choanal Atresia: Diagnosis, Management and Association with
CHARGE syndrome by Matthew Yantis, M.D. Department of
Otolaryngology Grand Rounds Presentation January 27, 2014
⢠Choanal Atresia: Diagnosis, Management, and Association with
CHARGE Syndrome Grand Rounds Presentation, Department of
Otolaryngology The University of Texas Medical Branch (UTMB
Health) Matthew Yantis, MD
⢠Choanal atresia by Fahad zakwan
