Tracheomalacia, bronchomalacia and tracheobronchomalacia

These conditions are characterised by excessive collapse of the trachea and main bronchi (intrathoracic trachea collapsing during exhalation and extrathoracic trachea collapsing during inhalation) associated with increased compliance of the airway wall, cartilaginous rings or both. It is a common finding in those born with OA/TOF. A prospective study found that 87% TOFs had TM. (7) TM can significantly impair secretion clearance, impair cough and increase risk of infection, and in turn delays recovery from infections. TBM can also aggravate airway reflux. There is also associated upper airway inflammation, with over a third found to have inflammation on bronchoscopy visually and even higher histologically.(8)

Pathophysiology

Cartilage deficiency and cilia loss at fistula site →Airway collapse →Retention secretions→ Bacterial colonisation →Chronic bronchitis → Recurrent pneumonia → Bronchiectasis. (12)

Complicating factors

The unique nature of the OA/TOF anatomy post-surgery means that many factors can aggravate the TM, which can cause flares in symptoms. These include:

• Vocal cord paralysis
• Extrinsic tracheal compression
• Oesophageal stricture
• Food bolus (this can press on the floppy trachea through the oesophagus wall)
• Recurrent aspiration
• Cardiac/ vascular anomalies, eg VACTERL, aorta scarred onto trachea and oesophagus post surgery
• Allergic sensitisation of airways (12)

Symptoms

• Dyspnoea
• Chronic brassy/hoarse cough
• Wheeze due to collapse of the tracheal lumen and not responsive to bronchodilators
• Recurrent respiratory tract infections
• Delayed recovery from infections
• Aggravation of airway reflux
• Difficulty clearing secretions (13)
• Exercise intolerance
• Impaired lung function (12)

Investigations

• Flexible bronchoscopy – This is the gold standard for investigation of TBM. It is recommended for anyone with OA/TOF with unexplained wheeze or exercise intolerance. (12) It may show upper airway inflammation – one prospective study found visible inflammation in a third of patients and higher levels histologically. (8,12)
• CT scan can also assess TBM.
• Spirometry can also assess severity of TBM.

Treatment

Aimed at improving secretion clearance

• Carbocysteine can thin sputum viscosity, aiding clearance.
• Hypertonic saline nebuliser/device to thin sputum viscosity. (10)
• Chest physiotherapy can also help facilitate secretion drainage.

Aimed at treating airway inflammation

• Bronchodilators should not be used as they may worsen airway collapse.
• Inhaled steroids should be used routinely in the presence of chronic airway inflammation and suspected pneumonia.
• Systemic steroids can also be helpful in suspected pneumonia.

Other treatments

• Annual influenza vaccination is recommended in people born with OA/TOF.
• Trial of anti-reflux treatment in those with persistent symptoms.
• Antibiotic threshold should be lower if there are worsening symptoms in a patient with TBM.
• Prophylactic azithromycin is recommended if there are persistent symptoms and a background of bronchiectasis. (12)