Introduction to Laryngomalacia-Bronchomalacia-Tracheomalacia

Laryngomalacia, tracheomalacia, and bronchomalacia are conditions characterized by excessive collapsibility of the upper and lower airways. These disorders can occur in isolation or in combination, affecting breathing and potentially leading to significant respiratory issues.

Key Concepts:

• These conditions are part of a spectrum of airway malacia disorders
• They involve weakness or floppiness of the airway structures
• Can be congenital or acquired
• May occur in isolation or as part of systemic disorders
• Severity ranges from mild to life-threatening

Understanding these conditions is crucial for pediatricians, pulmonologists, and otolaryngologists to ensure proper diagnosis, management, and long-term care of affected patients.

Laryngomalacia

Laryngomalacia is the most common cause of stridor in infants, accounting for 60-70% of congenital laryngeal anomalies.

Pathophysiology:

• Characterized by collapse of supraglottic structures during inspiration
• Involves floppiness of the epiglottis, aryepiglottic folds, and/or arytenoids
• May be associated with neurologic immaturity or altered laryngeal tone

Clinical Features:

• Inspiratory stridor, typically worse when supine or agitated
• Symptoms often worsen in the first 6 months, then improve by 12-18 months
• Feeding difficulties, particularly in severe cases
• Possible failure to thrive
• Sleep-disordered breathing or obstructive sleep apnea in some cases

Classification:

• Type 1: Prolapse of mucosa overlying the arytenoid cartilages
• Type 2: Foreshortened aryepiglottic folds
• Type 3: Posterior displacement of the epiglottis

Associated Conditions:

• Gastroesophageal reflux disease (GERD)
• Neurological disorders (e.g., cerebral palsy)
• Syndromes (e.g., Down syndrome)

Tracheomalacia

Tracheomalacia is characterized by excessive collapsibility of the tracheal walls, leading to airway obstruction during expiration.

Pathophysiology:

• Weakness of the tracheal cartilage
• Decreased or atrophic elastic fibers
• Widened posterior membranous wall

Types:

• Congenital: Associated with developmental abnormalities
• Acquired: Due to prolonged intubation, trauma, or chronic compression

Clinical Features:

• Expiratory stridor or wheeze
• "Barking" or "brassy" cough
• Recurrent respiratory infections
• Feeding difficulties and choking episodes
• Cyanotic spells in severe cases

Classification (based on location):

• Cervical tracheomalacia
• Intrathoracic tracheomalacia
• Diffuse tracheomalacia

Associated Conditions:

• Vascular rings or slings
• Esophageal atresia
• Tracheoesophageal fistula
• GERD

Bronchomalacia

Bronchomalacia refers to the weakening of the bronchial walls, leading to airway collapse during expiration.

Pathophysiology:

• Weakness or deficiency of bronchial cartilage
• Decreased elastic fibers in bronchial walls
• Can be localized or diffuse

Types:

• Primary: Congenital weakness of bronchial cartilage
• Secondary: Acquired due to external compression or chronic inflammation

Clinical Features:

• Chronic cough, often described as "honking"
• Expiratory wheezing or prolonged expiratory phase
• Recurrent bronchitis or pneumonia
• Exercise intolerance
• Atelectasis on chest imaging

Classification:

• Mild: <50% reduction in airway lumen
• Moderate: 50-75% reduction in airway lumen
• Severe: >75% reduction in airway lumen

Associated Conditions:

• Congenital heart diseases
• Bronchopulmonary dysplasia
• Cystic fibrosis
• Chronic lung disease

Diagnosis of Laryngomalacia-Bronchomalacia-Tracheomalacia

Clinical Evaluation:

• Detailed history and physical examination
• Observation of breathing patterns and auscultation
• Assessment of feeding and growth

Imaging Studies:

• Chest X-ray: May show hyperinflation or atelectasis
• Fluoroscopy: Dynamic airway assessment during respiration
• CT or MRI: For associated anomalies or vascular compression

Endoscopic Evaluation:

• Flexible laryngoscopy: Primary diagnostic tool for laryngomalacia
• Rigid bronchoscopy: Gold standard for tracheobronchomalacia diagnosis
• Dynamic airway evaluation during spontaneous breathing

Pulmonary Function Tests:

• Spirometry: May show obstructive pattern
• Flow-volume loops: Characteristic flattening of expiratory limb

Additional Tests:

• Polysomnography: For associated sleep-disordered breathing
• Echocardiogram: To rule out associated cardiac anomalies
• pH probe study: To assess for GERD

Management of Laryngomalacia-Bronchomalacia-Tracheomalacia

Conservative Management:

• Watchful waiting for mild cases
• Positioning techniques (e.g., prone or side-lying)
• Thickened feeds for infants with feeding difficulties
• Treatment of associated GERD
• Respiratory support: Supplemental oxygen or CPAP as needed

Surgical Interventions:

• Laryngomalacia:
  • Supraglottoplasty for severe cases
  • Epiglottopexy for type 3 laryngomalacia
• Tracheomalacia:
  • Aortopexy for severe cases with vascular compression
  • Tracheal stenting (controversial in children)
  • Tracheostomy for life-threatening cases
• Bronchomalacia:
  • Bronchial stenting in select cases
  • Bronchoplasty for localized severe disease

Medical Management:

• Inhaled bronchodilators for associated reactive airway disease
• Prophylactic antibiotics for recurrent infections
• Systemic or inhaled corticosteroids in select cases

Supportive Care:

• Nutritional support and feeding therapy
• Pulmonary rehabilitation and chest physiotherapy
• Immunizations, including RSV prophylaxis when indicated

Multidisciplinary Approach:

• Coordination between pulmonology, otolaryngology, and gastroenterology
• Regular follow-up to monitor growth and development
• Parent education and support

Prognosis and Complications

Prognosis:

• Laryngomalacia:
  • Most cases resolve spontaneously by 18-24 months of age
  • Excellent prognosis after supraglottoplasty for severe cases
• Tracheomalacia:
  • Many cases improve with growth and development
  • Severe cases may require long-term management
• Bronchomalacia:
  • Variable prognosis depending on extent and associated conditions
  • May persist into adulthood in some cases

Potential Complications:

• Recurrent respiratory infections
• Failure to thrive
• Developmental delays due to chronic hypoxia
• Cor pulmonale in severe, untreated cases
• Sudden death (rare, in severe untreated cases)

Long-term Considerations:

• Potential for exercise intolerance
• Increased risk of reactive airway disease
• Need for ongoing pulmonary follow-up
• Possible impact on quality of life in persistent cases

Factors Influencing Prognosis:

• Severity of the malacia
• Associated congenital anomalies or syndromes
• Timing of diagnosis and intervention
• Compliance with treatment and follow-up