- Newborn with difficulty breathing whilst feeding
- Narrowed nasal pyriform aperture
- Single central maxillary incisor, holoprosencephaly
Description
Congenital Pyriform Aperture Stenosis (CPAS) is a rare craniofacial anomaly characterised by the narrowing of the nasal pyriform aperture, the bony entrance to the nasal cavity. This condition can lead to significant nasal airway obstruction in neonates, given their obligate nasal breathing nature. CPAS may occur as an isolated anomaly or be associated with other craniofacial syndromes, such as holoprosencephaly.
Pathogenesis
The exact pathogenesis of CPAS is not fully understood, but it is believed to result from abnormal development of the nasal and maxillary processes during embryogenesis. Genetic factors may play a role, especially in cases associated with syndromic presentations.
Epidemiology, Risk Factors & Associations
- CPAS is a rare condition, with exact incidence rates difficult to ascertain.
- Male predominance has been noted in some case series.
- Associated with holoprosencephaly and single central maxillary incisor in syndromic cases.
Clinical Features
- Respiratory distress that worsens during feeding or crying.
- Difficulty in nasal breathing, observed as nasal flaring and retraction.
- Cyclical cyanosis that improves with crying (as the mouth opens, allowing for better air passage).
Complications
- Failure to thrive due to feeding difficulties.
- Chronic hypoxia can lead to developmental delays if not addressed promptly.
- Recurrent respiratory infections due to impaired nasal breathing.
Radiological Features
General Features
- Medial deviation of the maxillary nasal processes resulting in occlusion of the anterior nasal passages is diagnostic
CT
- Non-Contrast: The gold standard for diagnosis. Shows narrowing of the bony nasal aperture anteriorly, with the critical measurement being the width of the pyriform aperture. A measurement of less than 11 mm in a full-term neonate is diagnostic of CPAS.
- Presence of single central maxillary incisor is indicative of more complex syndromic associations.
Differential Diagnosis
Imaging-based
Midline facial anomalies should prompt brain imaging to exclude midline disorders such as holoprosencephaly (remember the phrase “the face predicts the brain”).
- Choanal atresia: Characterised by obstruction of the posterior nasal passages due to bony narrowing &/or soft tissue membranes. It can be unilateral or bilateral. Associated with CHARGE syndrome.
- Nasal septum deviation: Uncommon in neonates but may contribute to airway obstruction.
Clinically-based
- Nasal mass or cyst: Such as dacryocystocele, can lead to nasal obstruction.
Management
- Initial Management: Stabilisation of the airway, which may include nasal decongestants and humidified air. In severe cases, temporary airway support with nasal trumpets or intubation may be necessary.
- Surgical Intervention: Definitive treatment is surgical enlargement of the pyriform aperture. This is typically performed via sublabial or intranasal approach to remove the bony overgrowth obstructing the nasal entrance.