Investigations for Suspected Neonatal Laryngeal Anomalies

Initial Clinical Assessment

• Stridor characteristics (timing, severity, persistence, audibility) guide the decision to investigate for laryngeal anomalies – European Respiratory Society (ERS) recommendation. 1
• Associated symptoms such as hoarseness, weak cry, oxygen desaturation, apneic episodes, feeding difficulty, or failure to thrive increase suspicion for airway pathology – ERS. 1
• Severity of respiratory distress (degree of work of breathing and need for supplemental oxygen) should be evaluated before endoscopy – ERS. 3, 4

Primary Investigation – Flexible Bronchoscopy (FB)

• FB is the first‑line investigation for neonates with severe or persistent stridor, hoarseness, oxygen desaturation, or apnea – ERS. 1, 2
• Neonatal bronchoscopes with an outer diameter of 2.2–2.7 mm are suitable for all but the smallest preterm infants – ERS. 1, 5
• Nasal insertion of the flexible scope permits examination of the adenoids, larynx, and hypopharynx under physiological conditions while the stridor remains audible – ERS. 1, 2
• Both upper and lower airways must be inspected; abnormalities below the epiglottis are present in up to 68 % of neonates with laryngeal anomalies – ERS. 1, 2, 6

Diagnostic Yield of Flexible Bronchoscopy

These data reflect the most common reasons for performing FB in neonates – ERS. 7, 3, 4

• In a subgroup of 79 neonates with abnormal chest radiographs, only 19 % had normal FB findings; 28 % had tracheal/bronchial stenosis, 13 % vascular compression, with the remainder showing tracheomalacia, bronchomalacia, or granulomas – ERS. 7, 3, 4

Adjunctive Imaging – Laryngeal Ultrasound (LUS)

• LUS cannot reliably exclude a laryngeal cleft; when a cleft is strongly suspected, rigid bronchoscopy is required for definitive diagnosis – ERS. 1, 2, 8

Indications for Rigid Bronchoscopy

• Suspected laryngeal cleft (may be missed by FB) mandates rigid bronchoscopy – ERS. 1, 2, 8, 6
• Therapeutic needs such as foreign‑body removal or clearance of resistant mucus plugs require rigid bronchoscopy – ERS. 7, 3
• Detailed assessment of subglottic stenosis for surgical planning is an indication for rigid bronchoscopy – ERS. 7, 3

Radiographic Findings Prompting Endoscopy

• Chest radiography that shows persistent atelectasis, recurrent pneumonia, or mass lesions should trigger bronchoscopy – ERS. 7, 3, 4
• In the Paris neonatal series, 81 % of infants with abnormal chest radiographs had significant airway pathology confirmed by bronchoscopy – ERS. 7, 3, 4

Common Laryngeal Anomalies to Identify

• Laryngomalacia is the most frequent congenital laryngeal anomaly – ERS. 1, 2, 5
• Vocal‑cord paralysis ranks as the third most common congenital laryngeal anomaly – ERS. 1, 2, 5
• Additional anomalies that should be sought include laryngoceles, saccular cysts, laryngeal webs, atresia, laryngotracheal stenosis, laryngeal/tracheal clefts, and congenital hemangiomas – ERS. 1, 2, 5

Critical Pitfalls

• Limiting the examination to the larynx alone is unsafe; up to 68 % of affected neonates have concomitant lower‑airway abnormalities – ERS. 1, 2, 6
• Relying solely on flexible bronchoscopy when a laryngeal cleft is suspected can miss the diagnosis; rigid bronchoscopy is required – ERS. 1, 2, 8, 6
• A normal flexible bronchoscopy does not guarantee the absence of pathology but can be useful for excluding suspected problems and guiding management – ERS. 1, 2, 5
• In mechanically ventilated neonates with extubation failure, bronchoscopy should not be delayed because subglottic stenosis or other upper‑airway lesions may impede successful extubation – ERS. 7, 3, 4