- M/C cause of infant stridor (50-75%)
- M/C laryngeal anomaly in infants
The etiology of laryngomalacia is likely multifactorial, with anatomic, inflammatory, and neurologic factors all contributing to the disease process.
- Anatomical theory: Abnormal placement of flaccid tissue resulting in stridor
- Cartilaginous theory: Cartilages of the larynx are immature and abnormally pliable
- Neurologic theory (M/C accepted): Laryngomalacia may be a consequence of an underdeveloped or abnormally integrated CNS system, particularly the peripheral nerves and brainstem nuclei responsible for breathing and airway patency
Patients typically present with inspiratory stridor during the first few weeks of life, which usually worsens over the first 6 months of life and peaks in severity at about 6 months of age, followed by gradual improvement in the symptoms, with most patients being symptom free by age 18-24 months.
- Inspiratory stridor (classic faetures): Worse with agitation, crying, feeding, and supine positioning.
- Wheezing, coarse voice
- Feeding difficulty
- Gastroesophageal reflux disease (GERD)
- Obstructive sleep apnea
- Pulmonary hypertension (severe cases)
ComplicationsGiven that swallowing interrupts breathing, infants with airway compromise or respiratory distress may not be able to safely coordinate sucking, swallowing, and breathing, leading to dysphagia and aspiration.
- Severe respiratory distress: respiratory failure, apnea, cyanosis
- Feeding disorders: Swallowing and feeding difficulties with choking, regurgitation, and microaspiration events
- Failure to thrive
The diagnosis of laryngomalacia is suspected by the typical clinical history but is confirmed by flexible laryngoscopy in an awake infant.
- Clinical swallowing evaluations (CSE) (performed by a speech pathologist)
- Objective instrumental swallowing studies:
- Modified barium swallow studies (MBS)
- Fiberoptic endoscopic evaluation of swallowing (FEES) examinations
Flexible fiberoptic laryngoscopy:mainstay in the diagnostic evaluation of infant stridor for visualization of the upper aerodigestive tract during respiration.
- Collapse of supraglottic structures during inspiration, leading to inspiratory stridor and airway obstruction
- Inspiratory prolapse of the arytenoid cartilages
- Redundant arytenoid mucosa
- Shortened aryepiglottic folds
- Omega-shaped or tubular epiglottis
Surgical management is indicated in those with severe disease.
Surgical management:Common indications for surgery are stridor with respiratory compromise and feeding difficulties with failure to thrive
- Supraglottoplasty (mainstay of surgical treatment)
- Tracheostomy (reserved for life-threatening airway obstruction and who fail to improve after supraglottoplasty)