Which are the causes of Tracheobronchomalacia?

Tracheobronchomalacia (TBM) is a condition characterized by the excessive collapse of the tracheal and bronchial walls during breathing, typically caused by a deficiency in the structural integrity of the airway cartilage. While the exact etiology varies, it is fundamentally driven by either congenital structural weakness or acquired degradation of the airway support tissues.

What causes Tracheobronchomalacia?

Tracheobronchomalacia results from a loss of the normal rigidity of the airway walls. Think of the trachea like a vacuum cleaner hose: it is supported by C-shaped cartilage rings that keep it open. In Tracheobronchomalacia, these rings are either malformed, too soft, or damaged, causing the airway to flatten or collapse when you exhale or cough.

Is Tracheobronchomalacia genetic or acquired?

The condition is generally categorized into two distinct forms:

• Congenital Tracheobronchomalacia: Often present at birth, this is linked to developmental abnormalities where the cartilage fails to mature properly. It is sometimes associated with genetic syndromes like Polychondritis or connective tissue disorders, though it frequently occurs sporadically.


• Acquired Tracheobronchomalacia: This form develops later in life due to chronic inflammation, prolonged mechanical ventilation, or recurrent infections that weaken the airway walls over time.

What are the primary risk factors for airway collapse?

While causes are the direct physiological triggers, risk factors increase the likelihood of developing Tracheobronchomalacia. Key factors include:

• Chronic Obstructive Pulmonary Disease (COPD) or chronic bronchitis.


• External compression of the trachea from enlarged thyroids or vascular rings.


• Long-term exposure to airway irritants or trauma from intubation.


• Systemic connective tissue diseases that affect cartilage metabolism.

What does current research say about the etiology?

Researchers are currently investigating the molecular pathways involved in cartilage maintenance. Because Tracheobronchomalacia is complex, studies are focused on how inflammatory cytokines contribute to the degradation of the extracellular matrix in the airway. With 41 members currently sharing their experiences on DiseaseMaps.org, we are gaining a better understanding of how patient-reported symptoms correlate with different structural causes of Tracheobronchomalacia.

Next steps

• Consult a pulmonologist or an otolaryngologist for a dynamic airway evaluation, such as a cine-CT or bronchoscopy.


• Keep a symptom diary to track triggers, such as coughing or physical exertion, to discuss with your specialist.


• Join our community at DiseaseMaps.org to connect with others managing this condition.

Medical disclaimer: This information is for educational purposes only and should not replace professional medical advice, diagnosis, or treatment.

References

• NIH Genetic and Rare Diseases Information Center (GARD) - Tracheobronchomalacia.


• Orphanet: Portal for rare diseases and orphan drugs.


• OMIM (Online Mendelian Inheritance in Man) regarding connective tissue associations.


• American Thoracic Society (ATS) clinical guidelines on central airway obstruction.