Distinguishing Tracheobronchomalacia and Excessive Dynamic Airway Collapse on Dynamic CT Images

Expiratory central airway collapse (ECAC) is caused by anterior displacement of the posterior membrane (EDAC) or weakening of the cartilaginous walls (TBM). Differentiating the 2 is challenging, resulting in misdiagnosis and missed opportunities for patients. We investigated how accurately providers identify each pathology on computed tomographic (CT) images.

Images from 100 patients who underwent tracheobronchoplasty (TBP) were reviewed by 4 airway experts and categorized into TBM, EDAC, normal airway, or unknown by majority consensus. Selected images of patients with TBM (n=9) and EDAC (n=9) were distributed to respondents. Linear regression was used to investigate overall accuracy; inter-rater agreement was measured using Fleiss' kappa (κ).

We recruited 35 surgeons and 35 pulmonologists. Most practiced at an academic center (68.5%) and cared for patients with ECAC (61.4%). Among surgeons, 14 (40.0%) performed ≥5 complex airway cases yearly, and 13 (37.1%) performed TBP. Only 1 (1.5%) assigned the correct diagnosis to all 18 patients, while 13 (18.6%) identified <50.0% of the correct diagnoses. Inter-rater agreement for respondents was low (κ=0.21; 95% CI: 0.17-0.30; P<0.01). Predictors of accuracy included ≥10 years in practice (β=0.49; 95% CI: 0.03-0.95; P=0.03) and practicing pulmonology (β=0.72; 95% CI: 0.15-1.29; P=0.02).

Distinguishing EDAC and TBM is challenging, with poor agreement among clinicians. Therefore, clinicians should consider referring any patient with ECAC early for multidisciplinary evaluation.