A neonate presents with cyanosis that worsens with feeding and improves with crying. There is no nasal airflow bilaterally. The diagnosis is bilateral choanal atresia. The embryological basis is failure of:

• A Rupture of the nasobuccal membrane (bucconasal membrane) at 6 weeks gestation ✓
• B Fusion of the lateral nasal processes
• C Migration of neural crest cells to form the nasal bones
• D Formation of the primary palate from the medial nasal processes

Explanation

Choanal atresia results from failure of the bucconasal (nasobuccal) membrane to rupture at approximately 6 weeks of gestation, leaving a bony or membranous plate obstructing the posterior choana. Neonates are obligate nasal breathers, so bilateral atresia causes cyclical cyanosis that worsens with feeding (mouth needed for suckling) and improves with crying. Management requires immediate oral airway, then endoscopic or transpalatal surgical perforation and stenting.

Reference: Dhingra Diseases of Ear, Nose and Throat, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.