Chapter 31: Chronic Upper Airway Obstruction--mdash; LARYNGOMALACIA

Patient Story

A 4-month-old infant presents to your office with noisy breathing. His mother notes it began at a few weeks of life and has gradually worsened. The noise is described as a high-pitched wheeze with inspiration. It worsens when the baby is feeding, crying, or supine. Laryngoscopy confirms the diagnosis of laryngomalacia (Figure 31-1). The infant is treated with acid suppression therapy. The infant--rsquo;s symptoms resolve by 18 months of age.

Introduction

Laryngomalacia is a congenital abnormality of the larynx. It results in dynamic collapse of supraglottic structures leading to airway obstruction.

Synonyms

Laryngomalacias, Larynx chondromalacia.

Epidemiology

• Most common cause of stridor in newborns, affecting 45 to 75 percent of all infants with congenital stridor.¹

Etiology and Pathophysiology

• Exact etiology of laryngomalacia is unknown.

• Theories include anatomic displacement of flaccid tissue, immaturity of cartilage, neurologic underdevelopment affecting laryngeal function, and tone.¹

Risk Factors

• Gastroesophageal and laryngopharyngeal reflux.

• Neurologic disease.

• Secondary airway lesions.

• Congenital heart disease.

• Congenital abnormalities/genetic disorders.

Diagnosis

Clinical Features

• Presents with inspiratory stridor that typically worsens with feeding, crying, supine, or positioning.

• Symptoms begin within first few weeks of life, peak at 6 to 8 months, and usually resolve by 12 to 24 months.

• Common associated symptoms include regurgitation, coughing, choking, and slow feeding.

• Less common symptoms include respiratory distress, cyanosis, pectus excavatum, and failure to thrive.

Procedures

• Diagnosis suspected by clinical history and confirmed by awake dynamic flexible laryngoscopy.

• Typical features include supraglottic tissue prolapse during inspiration, omega-shaped epiglottis, retroflexed epiglottis, foreshortened aryepiglottic folds, and redundant arytenoid tissue (Figure 31-1).

• Based on history, patients may need to be screened for secondary, synchronous airway lesions.

Laboratory Testing and Imaging

• Usually not indicated. If there is concern for a synchronous airway lesion, may consider bronchoscopy or imaging.

Differential Diagnosis

• Subglottic stenosis--mdash;Congenital or acquired narrowing of the subglottic airway (Figure 31-2).

• Tracheomalacia--mdash;Flaccidity of tracheal cartilage leading to tracheal collapse especially with increased airflow (Figure 31-3).

• Vocal cord paresis or paralysis--mdash;Weakness or immobility of one or both vocal cords (Figure 31-4).