What is the management of tracheobronchomalacia?

Tracheobronchomalacia: Diagnosis and Management

Tracheobronchomalacia (TBM) is characterized by excessive collapse of the trachea and/or bronchi during expiration, causing significant respiratory symptoms that typically improve with conservative management in 90% of cases, though severe cases may require surgical intervention.

Definition and Pathophysiology

Tracheobronchomalacia refers to abnormal collapsibility of the central airways due to weakness in the cartilaginous support structures and/or excessive laxity of the posterior membranous wall. It can be:

• Primary/Congenital: Most common congenital tracheal anomaly (1 in 2100 children) 1
• Secondary/Acquired: Resulting from prolonged intubation, barotrauma, chronic inflammation, or external compression

TBM is classified based on anatomical involvement:

• Tracheomalacia: Isolated to the trachea
• Bronchomalacia: Affecting main bronchi
• Tracheobronchomalacia: Involving both structures

Clinical Presentation

Common symptoms include:

• Expiratory wheezing or stridor (often homophonous)
• Barking or "brassy" cough resistant to bronchodilators
• Recurrent respiratory infections
• Dyspnea that worsens with increased expiratory effort
• In infants: cyanotic episodes ("BPD spells") 2
• In severe cases: Acute life-threatening events (ALTE) or brief resolved unexplained events (BRUE) 3

Diagnostic Approach

1. Dynamic CT scan with inspiratory/expiratory phases:

   • Gold standard imaging modality
   • Shows excessive airway narrowing during expiration
   • May reveal "lunate" or "lemon" shape of trachea on inspiration 2
   • Low-dose techniques (40-80 mA) are comparable to standard higher-dose techniques 2

2. Flexible bronchoscopy:

   • Confirms diagnosis by visualizing dynamic airway collapse
   • In TBM, coronal narrowing with coughing exceeds 50% (vs. <40% in healthy individuals) 2
   • Allows assessment of other airway abnormalities

3. Pulmonary function tests:

   • May show flow-volume loop abnormalities
   • Helps evaluate severity and response to treatment

Management Algorithm

1. Mild to Moderate TBM (Asymptomatic or Minimal Symptoms)

• Observation and conservative management 2, 4

  • Most cases (90%) improve spontaneously with time, especially in children 2
  • Regular respiratory monitoring until remission

• Supportive care:

  • Prompt treatment of respiratory infections
  • Airway clearance techniques
  • Avoidance of triggers that increase expiratory effort

2. Moderate to Severe TBM (Symptomatic)

• Medical management:
  • Continuous positive airway pressure (CPAP) to maintain airway patency 2, 4
  • Treatment of comorbidities (gastroesophageal reflux, asthma)
  • Judicious use of nebulizer treatments
  • Minimal use of inhaled corticosteroids 1
  • Antibiotics for respiratory infections

3. Severe TBM (Life-threatening or Quality-of-Life Impacting)

• Surgical options (for cases unresponsive to conservative management):

  • Tracheobronchoplasty: Posterior membranous wall plication through right thoracotomy 5
  • Tracheopexy: Anterior or posterior fixation of the trachea 1, 3
  • Aortopexy: Relieves obstruction in virtually all patients with isolated tracheomalacia (100%), but less effective in tracheobronchomalacia (25%) 2

• Other interventions:

  • Tracheostomy: For severe cases requiring ventilatory support
  • Airway stenting: May provide temporary relief but has high complication rate (50%), including granulation tissue formation, migration, or erosion, with potential mortality 2

Special Considerations

• Children vs. Adults: TBM in children often improves with age as cartilage matures and airways stiffen naturally 2, 4

• Complications of stenting: Formation of granulation tissue, migration, erosion (50% of cases), and potential mortality (2 of 22 infants in one series) 2

• Surgical outcomes:

  • Vascular surgery (for compression): 88-100% improvement in respiratory symptoms 2
  • Tracheobronchoplasty: Generally good results with symptom improvement and better quality of life, though pulmonary function tests may not show significant improvement 5

• Common pitfalls:

  • Misdiagnosis as asthma due to similar wheezing presentation
  • Inappropriate use of bronchodilators, which may worsen symptoms in TBM by reducing airway tone
  • Failure to identify associated conditions (vascular rings, pulmonary hypertension)

TBM requires a high index of suspicion, particularly in patients with persistent wheezing despite standard treatments. Dynamic imaging and bronchoscopy are essential for accurate diagnosis, and management should be tailored to symptom severity, with most mild cases improving with conservative measures alone.