Difficult tracheal extubation in a patient with an unsuspected congenital subglottic stenosis.

A case is described of difficulty in advancing a tracheal tube and subsequent difficult extubation in an asymptomatic patient. The origin of this complication was an unsuspected subglottic stenosis, and a subsequent experiment showed how the relatively large folds of the cuff of an armoured tracheal tube could become caught on a narrow section of airway.