Can Choanal Stenosis Occur Unilaterally?
Yes, choanal stenosis and choanal atresia absolutely occur unilaterally, and in fact, unilateral presentation is common—accounting for approximately 48-60% of all cases 1, 2, 3.
Key Clinical Patterns
Distribution of Unilateral vs. Bilateral Disease
The evidence clearly demonstrates that choanal atresia/stenosis presents in both unilateral and bilateral forms:
- Unilateral cases: 48-60% of all choanal atresia/stenosis cases 1, 2, 3
- Bilateral cases: 40-46.5% of cases 1
- In the large German series of 41 patients, 14 had right-sided unilateral disease and 14 had left-sided unilateral disease, showing equal distribution between sides 1
Critical Clinical Distinction
Unilateral choanal stenosis/atresia is fundamentally different from bilateral disease in presentation and urgency:
- Bilateral cases are life-threatening in neonates due to obligate nasal breathing, requiring emergency surgical correction within the first week of life 1, 4
- Unilateral cases are typically NOT emergencies and often go undiagnosed for months, years, or even into adulthood 1, 2, 5, 4
Clinical Presentation Differences
Unilateral Disease
Unilateral choanal stenosis presents with:
- Mucoid nasal discharge (most common complaint) 1
- Upper airway infections 1
- Headache 1
- Rhinolalia 1
- Persistent unilateral nasal obstruction 5, 4
- Often mimics chronic sinusitis in adults 5
Association with Other Anomalies
Unilateral cases are significantly more likely to be isolated (occurring alone without other malformations):
- 53.2% of unilateral cases are isolated (no other congenital anomalies) 2
- Only 1.6% of bilateral cases are isolated 2
- Bilateral cases are strongly associated with CHARGE syndrome (25.6% of all cases), chromosomal abnormalities, and multiple congenital anomalies 1, 2
Timing of Surgical Intervention
For unilateral choanal atresia/stenosis, the recommended timing differs markedly from bilateral cases:
- Elective surgical correction before school age, preferably around age 2 years 1
- Some surgeons have performed correction as early as 6 months for unilateral cases 1
- The benefit of restored ventilation and drainage must be weighed against potential need for revision as the child grows 1
Important Clinical Pitfall
Unilateral choanal stenosis can remain undiagnosed until adulthood 5, 4. Clinicians should maintain high suspicion in adults with:
- Persistent unilateral nasal obstruction
- Recurrent unilateral sinusitis
- Unilateral nasal discharge
The diagnosis is confirmed by inability to pass a catheter through the affected nostril, nasal endoscopy, and CT imaging 1.
Acquired Forms
Choanal stenosis can also be acquired unilaterally, particularly after radiotherapy for nasopharyngeal carcinoma, with onset typically 2-40 months post-radiation 6. Two patients in one series developed severe unilateral choanal stenosis requiring surgical correction 6.