A proposed classification system of central airway stenosis

Tracheobronchial stenosis, a serious problem in adults and children, has multiple causes and has been treated in many ways. While developing an international multicentre study to evaluate efficacy of airway stents, it was realised that no adequate description of central airway stenosis regarding type, location and degree has been published. Thus, comparing results of different treatment modalities in different centres has been difficult due to a lack of uniformity of classification. Reports are typically descriptive and precise classification schemes have not adequately addressed either for the trachea or the main bronchi. A standardised classification scheme was proposed with descriptive images and diagrams for rapid and uniform classification of central airway stenosis. The present authors' system divides stenosis into structural and dynamic types and further classifies the disease by degree of stenosis, location and transition zone. Multiple sites can be described and each is transformed into a simple numerical scoring system prompted by a diagram, which can be easily captured for subsequent uniform analysis across sites. A pilot validation of the system, with 18 pulmonologists of varying training background, showed strong precision and agreement between observers. Such a system will enhance the ability to study the effectiveness of treatment modalities for central airway stenosis.