Laryngomalacia

Laryngomalacia is the most common congenital laryngeal anomaly and the leading cause of stridor in infants: dynamic collapse of supraglottic structures into the airway during inspiration.

• Mechanisms: neuromuscular immaturity, excessive redundancy of arytenoid mucosa, short aryepiglottic folds, and an omega shaped or tubular epiglottis that curls on itself.
• Anatomical patterns: prolapse of redundant arytenoid mucosa, foreshortened aryepiglottic folds, posterior displacement of the epiglottis, and combinations.
• Association with gastro oesophageal reflux (common), neurological disease (hypotonia, cerebral palsy), genetic syndromes (trisomy 21, CHARGE), and cardiac disease.
• Natural history: onset in the first 2 weeks of life, peak severity at 6 to 8 months, resolution by 12 to 24 months in over 90 percent of mild to moderate cases.

• Inspiratory stridor, high pitched and fluttering ("crowing"), worse when supine, feeding, crying, agitated, or with a respiratory infection, and improved prone, in a calm state, or with neck extension.
• Mild: stridor only with normal feeding and growth.
• Moderate: feeding difficulty, regurgitation, mild suprasternal and subcostal retractions, and some interrupted feeds.
• Severe: failure to thrive, apnoea, cyanotic episodes, marked retractions, pectus excavatum, pulmonary hypertension, and cor pulmonale.
• Reflux symptoms: vomiting, irritability with feeds, arching, and cough.
• Voice and cry are normal, which distinguishes it from vocal fold paralysis and subglottic lesions.

• Clinical history and examination are suggestive; confirmation is by awake flexible laryngoscopy (transnasal), which shows collapse of the supraglottic structures during inspiration. The study must be done in spontaneous breathing without sedation.
• Synchronous airway lesions occur in 15 to 20 percent of children (subglottic stenosis, tracheomalacia, vocal fold paralysis, laryngeal cleft); formal airway endoscopy under anaesthesia is indicated for severe disease, discordant findings, failure to thrive, cyanotic or hypoxic events, or when stridor is atypical (biphasic, persistent beyond 18 months, or associated with an abnormal cry).
• Overnight oximetry or polysomnography for suspected obstructive sleep apnoea or hypoxaemia.
• Evaluation of feeding and swallowing: modified barium swallow or fibreoptic endoscopic evaluation of swallowing for aspiration.
• Echocardiography in severe disease (pulmonary hypertension).
• Genetic and neurological evaluation if dysmorphism, hypotonia, or other malformations are present.

• Mild disease: reassurance, observation, and monitoring of weight at 1 to 3 month intervals; educate parents about positioning (head elevated or prone supervised awake, supine only for sleep), safe sleeping, and when to seek urgent care (cyanosis, apnoea, poor feeding, respiratory distress).
• Moderate disease: feeding adjustments (small frequent feeds, upright feeding, paced bottle, thickened feeds, nipple flow control, calorie fortification) and treatment of reflux.
• Reflux treatment when symptoms or endoscopic signs (arytenoid oedema, erythema) are present: omeprazole 0.7 mg/kg to 1 mg/kg orally once daily or esomeprazole 1 mg/kg once daily for 4 to 8 weeks, then reassess and stop when asymptomatic. Avoid indefinite use without indication.
• Supraglottoplasty is indicated for severe disease: failure to thrive, recurrent apnoea or cyanosis, cor pulmonale, hypoxaemia, and severe feeding difficulty with aspiration:
  • Endoscopic division of the shortened aryepiglottic folds, trimming of redundant arytenoid mucosa, and when needed epiglottopexy or partial epiglottic reduction, using cold steel, CO2 laser, or microdebrider. Bilateral posterior procedures should be avoided to reduce stenosis.
  • Success rate about 90 percent in isolated laryngomalacia; lower with neurological disease, syndromes, or synchronous lesions.
  • Postoperative: observation in a unit with airway skills, dexamethasone 0.25 mg/kg every 6 hours for 24 hours, humidified air, and PPI therapy; feeding resumes early.
• Tracheostomy is rarely needed and reserved for failed supraglottoplasty or severe multi level obstruction.
• Complications of supraglottoplasty: supraglottic stenosis, granuloma, aspiration, and bleeding.
• Follow up until resolution of stridor and normal growth; revise the diagnosis if symptoms persist beyond 24 months.