Subglottic stenosis: Correlation between computed tomography and bronchoscopy

The evaluation of subglottic stenosis has been limited by the lack of stand ardized methods for determining the cross-sectional area and length of the stenotic segment. A rabbit model was used to prospectively evaluate the cor relation between computed tomography (CT) and bronchoscopy in the evaluatio n of this disease. Subglottic stenosis was produced in 39 New Zealand White rabbits by a transoral endoscopic technique. The animals were evaluated 3 weeks later with spiral CT, rigid bronchoscopy, and open laryngotracheal ex ploration. Spiral CT was performed with the location, degree, and length of subglottic stenosis being determined by a blinded observer. Each animal th en underwent rigid bronchoscopy and open laryngotracheal exploration for de termination of the same measurements. Data were analyzed to determine the c orrelation between the radiographic and surgical techniques in evaluating t he airway stenosis. With regard to the degree of stenosis, 94% of the rabbi ts were determined to have CT and bronchoscopic measurements that were with in 15% (Pearson correlation .94, p < .05). With regard to the length of ste nosis, 94% of animals had a measurement on CT that was within 2 mm of that observed upon open exploration (Pearson correlation .81, p < .05). The CT e valuation of subglottic stenosis correlated well with the currently used me thod of visual inspection at bronchoscopy in evaluating tracheal stenosis i n this animal model. These data suggest that CT could serve as a useful adj unct in the evaluation of tracheal stenosis, especially when serial examina tions are required.