Volume relationships between cricoid and main stem bronchi in children using three-dimensional computed tomography imaging

Abstract

There are limited data to guide the selection of the appropriate sized endobronchial tube for main stem intubation to provide one-lung ventilation in children. The relationship between the cricoid and the main bronchi (right and left) has been previously evaluated using two-dimensional computed tomography (CT) imaging and video-bronchoscopic images. The present study defines the three-dimensional, CT-derived volume-based relationships between the right main-stem bronchus (RMB), left main-stem bronchus (LMB), and the cricoid ring. The three-dimensional CT images of 35 children, less than 8 years of age, undergoing radiological evaluation unrelated to airway or mediastinal symptomatology were examined. The images of the airway column were evaluated at the level of the cricoid and main stem bronchi (right and left). Volumes were calculated and comparisons made between these levels. There was no statistically significant difference based on gender for the cricoid and main stem bronchi volumes. A statistically significant difference was observed between the cricoid and left main stem bronchi volumes as well as between the right and left main stem bronchi. The relationship (ratio) between the volumes of the cricoid and main stem bronchi remains constant by age. The cricoid dimensions can be used to predict the main stem bronchi dimensions.