Pathophysiology of subglottic tracheal stenosis in childhood.

Two particularly problematic clinical entities are chosen from the many possible causes of the pathophysiology of subglottic tracheal stenoses in childhood: malformations of the "hard" and "soft" types of stenosis occurring typically as primary lesions; and stenoses caused by trauma (following intubation or faulty tracheostomy) as the most common secondary lesions. It is shown with reference to experimental investigations that subepithelial layers play the leading role in the origin of stenoses, in contrast to hitherto existing ideas based on clinical observations. Traumatic stenoses caused by unphysiological mechanical stressing show striking parallels to those in other age groups, suggesting the conclusion that a reaction of the mesenchymal tissue layers of the airway regions in question is a typical response to mechanical forces.