Measurement of tracheal size in children with congenital heart disease by computed tomography

Background To establish a reference of tracheal size in children with congenital heart disease to allow detection of airway stenosis. Methods We conducted a retrospective study using existing data from children referred for computed tomography (CT) scanning. From January 1999 to February 2001, 540 consecutive children with congenital heart disease who received electron beam CT scanning at our hospital were considered eligible for inclusion in the study. After exclusion criteria were considered, 99 children (50 girls and 49 boys; aged 4 days to 16 years 10 months) were enrolled in the study. Tracheal width was measured at three levels on CT images. The relationship between tracheal width and the patientʹs height, weight, age, and sex were analyzed by multiple regression and formula transformation. Results Height was the most effective parameter for predicting the transverse diameter of the intrathoracic trachea, and tracheal size could be predicted based on height using the established equations. In addition, tracheal width increased from the thoracic inlet to the carina. Reference curves based on the subjectʹs height were created for convenient use. Conclusions Tracheal stenosis in children with congenital heart disease may be diagnosed by comparing the size of the trachea of the individual to the 95% confidence interval of predicted values based on the patientʹs height.