PT  - JOURNAL ARTICLE
AU  - Alexandros Mitropoulos
AU  - Woo-Jung Song
AU  - Fatma Almaghlouth
AU  - Samuel Kemp
AU  - Michael Polkey
AU  - James H. Hull
TI  - Detection and diagnosis of large airway collapse: a systematic review
AID  - 10.1183/23120541.00055-2021
DP  - 2021 Jul 01
TA  - ERJ Open Research
PG  - 00055-2021
VI  - 7
IP  - 3
4099  - http://openres.ersjournals.com/content/7/3/00055-2021.short
4100  - http://openres.ersjournals.com/content/7/3/00055-2021.full
SO  - erjor2021 Jul 01; 7
AB  - Large airway collapse (LAC) is a frequently encountered clinical problem, caused by tracheobronchomalacia +/− excessive dynamic airway collapse, yet there are currently no universally accepted diagnostic criteria. We systematically reviewed studies reporting a diagnostic approach to LAC in healthy adults and patients, to compare diagnostic modalities and criteria used. Electronic databases were searched for relevant studies between 1989 and 2019. Studies that reported a diagnostic approach using computed tomography (CT), magnetic resonance imaging or flexible fibreoptic bronchoscopy were included. Random effects meta-analyses were performed to estimate the prevalence of LAC in healthy subjects and in patients with chronic obstructive airway diseases. We included 41 studies, describing 10 071 subjects (47% female) with a mean±sd age of 59±9 years. Most studies (n=35) reported CT findings, and only three studies reported bronchoscopic findings. The most reported diagnostic criterion was a ≥50% reduction in tracheal or main bronchi calibre at end-expiration on dynamic expiratory CT. Meta-analyses of relevant studies found that 17% (95% CI: 0–61%) of healthy subjects and 27% (95% CI: 11–46%) of patients with chronic airways disease were classified as having LAC, using this threshold. The most reported approach to diagnose LAC utilises CT diagnostics, and at a threshold used by most clinicians (i.e., ≥50%) may classify a considerable proportion of healthy individuals as being abnormal and having LAC in a quarter of patients with chronic airways disease. Future work should focus on establishing more precise diagnostic criteria for LAC, relating this to relevant physiological and disease sequelae.CT is mostly used to diagnose LAC, and at a threshold used by most clinicians (i.e. ≥50%) that would classify a large proportion of healthy individuals as being abnormal and LAC in a quarter of patients with chronic airway diseases https://bit.ly/3izAuSk