Plain Neck Radiography for Triage of High Grade Laryngotracheal Stenosis: A Retrospective Diagnostic Accuracy Study

Description

Abstract Background: In low-resource settings, endoscopic confirmation of laryngotracheal stenosis (LTS) is often delayed. Plain neck radiography is widely available but lacks validation for severity triage. We validated radiographic criteria for detecting high-grade stenosis requiring urgent intervention. Methods: This STARD 2015 compliant retrospective study at a South African tertiary hospital included consecutive patients (≥12 years) with endoscopically confirmed acquired LTS (2005 2024). Two blinded radiologists assessed soft tissue neck radiographs for minimal central airway diameter and qualitative signs. The reference standard was laryngotracheobronchoscopy with Cotton Myer grading. The primary outcome was diagnostic accuracy for high grade stenosis (Grade III IV). Results: Among 176 patients (median age 24 years, 64% male, 91% Black), high grade stenosis prevalence was 74% (130/176). Minimal diameter correlated strongly with endoscopic grade (Spearman's ρ = –0.81). For detecting high grade stenosis, a diameter ≤7 mm yielded sensitivity 94.2% (95% CI 89.3 97.3), specificity 88.9% (95% CI 75.9 96.3), positive likelihood ratio 8.5, negative likelihood ratio 0.07, and AUC 0.96 (95% CI 0.93 0.98). Inter rater reliability was excellent (ICC = 0.92 for diameter; κ 0.78 0.91 for signs). Diagnostic performance was similar across PROGRESS Plus strata. The ≤7 mm threshold closely approximated the data derived optimal threshold (6.8 mm). Conclusions: A minimal central airway diameter ≤7 mm on plain neck radiography accurately identifies high grade LTS requiring urgent intervention. This derived and internally validated threshold may assist referral prioritisation where endoscopy is delayed or unavailable. Prospective multi centre validation is warranted. Keywords: Airway obstruction; Cotton-Myer grade; Diagnostic accuracy; Laryngotracheal stenosis; Plain radiography; Resource-limited settings; Triage

Institutions

• Walter Sisulu University

  Eastern Cape, Mthatha

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Licence