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Tracheomalacia/Laryngomalacia, Pediatric

Basics

Description

- Laryngomalacia - Anatomic abnormalities: - Short aryepiglottic folds - Elongated, flaccid, omega-shaped epiglottis prolapses posteriorly. - Redundant arytenoid mucosa

- Tracheomalacia - Weakness of the tracheal wall secondary to softening of the anterior cartilaginous rings and/or decreased tone of the posterior membranous wall - Classified as primary or secondary - Primary: congenital; results from immature development of the tracheal structures; may occur with other congenital anomalies such as tracheoesophageal fistula, laryngomalacia, and facial anomalies - Secondary: acquired in a normally developed trachea after some insult such as prolonged positive pressure ventilation, recurrent infection or aspiration, or external compression

- Tracheomalacia - Primary: Symptoms may be delayed until 2 " 3 months of age. - Secondary: Symptoms delayed until after causative insult occurs. - Expiratory wheeze, if intrathoracic portion of trachea involved - Inspiratory stridor, if extrathoracic portion of trachea involved - Harsh barking cough - Symptoms worsen with crying, agitation, feeding, and infections. - Impaired mucus clearance, frequent infections - Rarely, cyanosis, hyperextension of neck, breath-holding spells, feeding difficulties

- Laryngomalacia - High-pitched or vibratory, inspiratory stridor - Suprasternal retractions - Positional changes noted: usually worsens with flexion of neck, supine position - Stridor transmitted throughout the chest on auscultation

- Barium esophagography - Used to evaluate for external vascular compression of the esophagus - Might help to identify gastroesophageal reflux

- Chest radiograph - Usually normal in both laryngomalacia and tracheomalacia - Important to rule out other causes of chronic cough or abnormalities that may cause external airway compression

- Airway fluoroscopy - Insensitive except in severe cases; unable to visualize AP and lateral caliber simultaneously

- CT - Paired end-inspiratory and dynamic expiratory multidetector CT, free-breathing cine CT " both sensitive and specific - Exposure to radiation

- Laryngomalacia: differential diagnosis of chronic stridor - Vocal cord abnormalities: vocal cord paralysis/paresis - Laryngeal abnormalities: laryngeal cleft, laryngeal web, subglottic hemangioma, papilloma - Subglottic stenosis (biphasic stridor)

- Tracheomalacia: differential diagnosis of chronic homophonous wheeze - Structural abnormalities: vascular compression/ring, tracheal stenosis/web, cystic lesion, mass/tumor - Nonstructural abnormalities: gastroesophageal reflux disease (GERD), retained foreign body, persistent bacterial bronchitis

- Tracheomalacia - For severe cases, little evidence supporting noninvasive and surgical therapies - Tracheostomy may be needed in severe cases to bypass lesion or to provide continuous positive airway pressure. - Consider aortopexy (suspending the anterior trachea to widen the airway) in severe cases refractory to more conservative management. - Airway stents are associated with significant complications; reserved for children with otherwise poor prognosis - External airway splints currently under investigation

  • Malacia refers to "softness " of airway structures.
  • LaryngomalaciaDynamic collapse of the supraglottic structures of the larynx resulting in airway obstructionMost common congenital anomaly of the larynxMost common noninfectious cause of stridor in children
  • TracheomalaciaDynamic collapse of the trachea resulting in airway obstructionCommon cause of chronic wheezing in infants and childrenClinical manifestations depend on if lesion is part of the intrathoracic or extrathoracic portions of the trachea.

Etiology

  • LaryngomalaciaAnatomic abnormalities:Short aryepiglottic foldsElongated, flaccid, omega-shaped epiglottis prolapses posteriorly.Redundant arytenoid mucosaNeurologic abnormalities:Immaturity of neuromuscular control results in hypotonia of pharyngeal muscles.
  • TracheomalaciaWeakness of the tracheal wall secondary to softening of the anterior cartilaginous rings and/or decreased tone of the posterior membranous wallClassified as primary or secondaryPrimary: congenital; results from immature development of the tracheal structures; may occur with other congenital anomalies such as tracheoesophageal fistula, laryngomalacia, and facial anomaliesSecondary: acquired in a normally developed trachea after some insult such as prolonged positive pressure ventilation, recurrent infection or aspiration, or external compressionDuring exhalation, increased collapsing pressure across a compliant airway wall causes invagination of the posterior membrane.With increasing age, the length, area, thickness, and amount of cartilage increases in the anterior rings as well as the size and contractility of the membranous wall.

Diagnosis

History

  • LaryngomalaciaSymptoms may be present at birth or delayed until 1 " 2 months of age.Inspiratory stridorMay be asymptomatic during sleep or quiet breathingWorsens with crying, agitation, feeding, upper respiratory infections, supine positioning
  • TracheomalaciaPrimary: Symptoms may be delayed until 2 " 3 months of age.Secondary: Symptoms delayed until after causative insult occurs.Expiratory wheeze, if intrathoracic portion of trachea involvedInspiratory stridor, if extrathoracic portion of trachea involvedHarsh barking coughSymptoms worsen with crying, agitation, feeding, and infections.Impaired mucus clearance, frequent infectionsRarely, cyanosis, hyperextension of neck, breath-holding spells, feeding difficulties

Physical Exam

  • LaryngomalaciaHigh-pitched or vibratory, inspiratory stridorSuprasternal retractionsPositional changes noted: usually worsens with flexion of neck, supine positionStridor transmitted throughout the chest on auscultation
  • TracheomalaciaHomophonous expiratory wheeze (intrathoracic malacia)High-pitched inspiratory stridor (extrathoracic malacia)Intercostal retractions, worse during activity, and acute respiratory infections

Diagnostic Tests & Interpretation

Diagnostic Procedures/Other

  • Flexible fiberoptic laryngo/bronchoscopyGold standard for diagnosis of dynamic airway collapsePerformed during spontaneous breathingVisualize the degree, extent, and location of laryngomalacia and/or tracheomalacia.Evaluate for other airway lesions in the differential diagnosis.
  • Barium esophagographyUsed to evaluate for external vascular compression of the esophagusMight help to identify gastroesophageal reflux
  • Chest radiographUsually normal in both laryngomalacia and tracheomalaciaImportant to rule out other causes of chronic cough or abnormalities that may cause external airway compression
  • Airway fluoroscopyInsensitive except in severe cases; unable to visualize AP and lateral caliber simultaneously
  • MRIUseful to evaluate for extrinsic vascular airway compression
  • CTPaired end-inspiratory and dynamic expiratory multidetector CT, free-breathing cine CT " both sensitive and specificExposure to radiation
  • Pulmonary function testsMight show flow limitation, typical notching in expiratory portion of flow-volume loop

Differential Diagnosis

  • Laryngomalacia: differential diagnosis of chronic stridorVocal cord abnormalities: vocal cord paralysis/paresisLaryngeal abnormalities: laryngeal cleft, laryngeal web, subglottic hemangioma, papillomaSubglottic stenosis (biphasic stridor)
  • Tracheomalacia: differential diagnosis of chronic homophonous wheezeStructural abnormalities: vascular compression/ring, tracheal stenosis/web, cystic lesion, mass/tumorNonstructural abnormalities: gastroesophageal reflux disease (GERD), retained foreign body, persistent bacterial bronchitis

Alert

  • The differential diagnosis for stridor in children includes life-threatening causes.
  • If history or clinical course deviates from expected pattern, consider comorbidities (asthma, GERD) or investigating for alternative diagnosis.
  • Investigate lower airways in more severe cases of laryngomalacia for other airway anomalies.
  • The use of beta2 agonists may increase the tracheal wall collapsibility by decreasing muscular tone, thereby making the symptoms worse.
  • Bronchoscopy should ideally be done under conscious sedation during spontaneous breathing to avoid altering vocal cord movement and airway dynamics.
  • The use of rigid bronchoscopy may stent open the trachea, making tracheomalacia more difficult to identify; flexible bronchoscopy is a more appropriate test.

Treatment

General Measures

  • LaryngomalaciaMost cases resolve spontaneously by 15 " 18 months of age.Observation and reassuranceConsider feeding modifications (pacing, positioning, texture change).Strong association with GERD. Treat if symptomatic; empiric treatment is controversial.
  • TracheomalaciaUsually resolves spontaneously by 18 " 24 months of ageObservation and reassurance, chest physiotherapy for mucus clearanceTreatment of exacerbating factors, such as upper respiratory infections, asthma, or GERD

Surgery

  • Laryngomalacia10% of cases of laryngomalacia are severe (apnea, cyanosis, severe retractions, failure to thrive, feeding difficulty, obstructive apnea), and require further investigation and treatment.Supraglottoplasty: excision of redundant arytenoid mucosa, trimming of epiglottis, division of tight aryepiglottic foldsTracheostomyPostoperative complications: scarring, dysphagia
  • TracheomalaciaFor severe cases, little evidence supporting noninvasive and surgical therapiesTracheostomy may be needed in severe cases to bypass lesion or to provide continuous positive airway pressure.Consider aortopexy (suspending the anterior trachea to widen the airway) in severe cases refractory to more conservative management.Airway stents are associated with significant complications; reserved for children with otherwise poor prognosisExternal airway splints currently under investigation

Ongoing Care

Follow-up Recommendations

Monitor for recurrent respiratory symptoms, poor growth, and other exacerbating conditions (asthma, GERD).

Prognosis

  • In cases of isolated laryngomalacia and/or tracheomalacia, prognosis is usually excellent.
  • In patients with history of tracheoesophageal fistula, vascular ring, or other airway anomalies, tracheal dysfunction may persist after corrective surgery.

Additional Reading

  • Ambrosio A, Brigger MT. Pediatric supraglottopasty. Adv Otorhinolaryngol. 2012;73:101 " 104. [View Abstract]
  • Carden KA, Boiselle PM, Waltz DA, et al. Tracheomalacia and tracheobronchomalacia in children and adults: an in-depth review. Chest. 2005;127(3):984 " 1005. [View Abstract]
  • Kugler C, Stanzel F. Tracheomalacia. Thorac Surg Clin. 2014;24(1):51 " 58. [View Abstract]
  • Masters IB. Congenital airway lesions and lung disease. Pediatr Clin North Am. 2009;56(1):227 " 242. [View Abstract]
  • Masters IB, Chang AB. Tracheobronchomalacia in children. Expert Rev Respir Med. 2009;3(4):425 " 439. [View Abstract]

Codes

ICD09

  • 748.3 Other anomalies of larynx, trachea, and bronchus

ICD10

  • Q32.0 Congenital tracheomalacia
  • Q31.5 Congenital laryngomalacia

SNOMED

  • 95434006 tracheomalacia (disorder)
  • 253737007 Congenital laryngomalacia (disorder)
  • 95467005 Congenital tracheomalacia (disorder)
  • 308232009 Laryngotracheomalacia (disorder)
  • 38086007 laryngomalacia (disorder)

FAQ

  • Q: When will the symptoms improve?
  • A: As anatomic structures mature with age, laryngomalacia symptoms may improve by 6 months of age, with usual resolution by 18 months of age. Primary tracheomalacia may last longer, but in both entities symptoms usually resolve completely by age 2 years. Natural history of secondary tracheomalacia is dependent on cause.
  • Q: Should all patients have an endoscopic evaluation?
  • A: No. Diagnosis is usually made based on the history and physical examination. Infants with mild to moderate typical presentation need only careful monitoring for recurrence or worsening of symptoms and for poor growth. However, airway evaluation should be performed in all cases where a different pathology is considered or when symptoms worsen or persist past the expected age of resolution.