Laryngomalacia-Bronchomalacia-Tracheomalacia
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
Laryngomalacia-Bronchomalacia-Tracheomalacia
- What is the common feature of laryngomalacia, bronchomalacia, and tracheomalacia?
Excessive collapsibility of the airway structures during respiration - Which age group is most commonly affected by laryngomalacia?
Infants, typically presenting in the first few weeks of life - What is the characteristic sound associated with laryngomalacia?
Inspiratory stridor, often described as a high-pitched wheeze - How does feeding affect the symptoms of laryngomalacia?
Symptoms often worsen during feeding due to increased negative pressure in the airway - What is the most common cause of chronic stridor in infants?
Laryngomalacia - How is the diagnosis of laryngomalacia typically confirmed?
Flexible laryngoscopy showing collapse of supraglottic structures during inspiration - What is the natural history of laryngomalacia in most cases?
Spontaneous resolution by 12-18 months of age - When is surgical intervention considered in laryngomalacia?
In severe cases with feeding difficulties, failure to thrive, or obstructive sleep apnea - What is the most common surgical procedure for severe laryngomalacia?
Supraglottoplasty - How does tracheomalacia differ from laryngomalacia?
Tracheomalacia involves collapse of the tracheal walls, while laryngomalacia affects supraglottic structures - What are the common symptoms of tracheomalacia?
Expiratory stridor, barking cough, and recurrent respiratory infections - How is the diagnosis of tracheomalacia confirmed?
Dynamic airway evaluation with flexible bronchoscopy or dynamic CT - What conditions are often associated with tracheomalacia?
Tracheoesophageal fistula, vascular rings, and chronic lung disease - How does positive pressure ventilation affect patients with tracheomalacia?
It can temporarily improve airway patency by stenting the airway open - What is bronchomalacia?
Excessive collapsibility of the bronchi during expiration - How does bronchomalacia typically present in children?
Persistent wheezing, recurrent pneumonia, and atelectasis - What imaging technique can help diagnose bronchomalacia non-invasively?
Dynamic expiratory CT scan - How does the management of bronchomalacia differ from that of asthma?
Bronchodilators may worsen symptoms in bronchomalacia by increasing airway collapsibility - What is the role of continuous positive airway pressure (CPAP) in managing these conditions?
It can provide pneumatic stenting of the airway, reducing collapse - How does gastroesophageal reflux disease (GERD) relate to these conditions?
GERD is often associated with airway malacia and can exacerbate symptoms - What is the concept of synchronous airway lesions?
The presence of multiple levels of airway malacia or other airway abnormalities - How does airway malacia affect a child's ability to clear secretions?
It impairs effective cough and mucociliary clearance, predisposing to infections - What is the role of tracheostomy in severe cases of tracheomalacia?
It can bypass the collapsible segment and provide a stable airway - How does exercise tolerance typically change as children with airway malacia grow?
It often improves with age as the airway cartilage becomes more rigid - What is aortopexy, and when is it considered in tracheomalacia?
Surgical attachment of the aorta to the sternum to relieve compression on the trachea, considered in severe cases - How does crying affect the symptoms of laryngomalacia?
It often improves stridor temporarily due to increased airway tone - What is the significance of pectus excavatum in children with tracheomalacia?
It can exacerbate tracheal compression and symptoms - How does positioning affect symptoms in infants with laryngomalacia?
Prone positioning often improves symptoms by reducing supraglottic collapse - What is the role of polysomnography in evaluating children with airway malacia?
It assesses for obstructive sleep apnea, which can be associated with severe malacia - How does airway malacia affect the approach to mechanical ventilation?
It may require higher PEEP or longer inspiratory times to maintain airway patency
Further Reading
- Laryngomalacia: A Review and Summary of Current Clinical Practice - Comprehensive review in Paediatric Respiratory Reviews
- Tracheobronchomalacia and Excessive Dynamic Airway Collapse - American Journal of Respiratory and Critical Care Medicine
- Bronchomalacia in children: pathophysiology, diagnosis and management - European Respiratory Journal
- Evaluation and Management of Laryngomalacia - Pediatric Clinics of North America
