Correlations of Radiographic and Endoscopic Observations in Subglottic Stenosis

Objective(s): Subglottic stenosis (SGS) represents a constellation of diverse pathologic processes that ultimately lead to narrowing of the subglottic region and can produce significant morbidity. Existing endoscopic and radiographic assessments may not be consistent in practice. Methods: Severity of stenosis was evaluated and reported using the Cotton-Myer classification system from 33 endoscopic procedures from 32 unique subjects. Radiographic imaging within the preceding 3 month period was subsequently reviewed and narrowing was measured by a blinded radiologist. Degree of stenosis was reported as a percentage in 30 out of 33 endoscopic evaluations and subsequently compared to radiographically determined percentage of stenosis. Statistical analyzes were conducted to evaluate concordance between endoscopic and radiographic assessments. Results: About 45.5% (15/33) of the evaluations were in agreement using Cotton-Myer scoring, while 27.3% (9/33) were discrepant by 1 grade and 27.3% (9/33) by 2 grades. Correlation of degree of stenosis as a percentage using Spearman (coefficient: 0.233, P-value: .214) and Pearson (coefficient: 0.138, P-value: .466) methods demonstrated very weak relationships. Radiographic scoring did not predict endoscopic classification to a significant degree using mixed effects regression. Conclusions: Radiographic and endoscopic grading of subglottic stenosis may not be reliably concordant in practice.