Quantitative investigation of airway lumen and area changes before and after surgical tracheostomy using CT imaging: A multicentre retrospective cohort study

Post-tracheostomy airway narrowing may be observed after decannulation, but its persistence and clinical significance remain uncertain; quantitative evidence describing post-tracheostomy tracheal changes remains limited. This multicentre retrospective cohort study aimed to quantify computed tomography (CT)-based changes in tracheal area and minimal diameter before tracheostomy and after decannulation and to characterise the longitudinal anatomical variability of post-tracheostomy airway changes. Adult patients who underwent surgical tracheostomy between 2014 and 2024 across five affiliated hospitals were reviewed. Inclusion required both pre-tracheostomy and post-decannulation CT imaging. The tracheal area and minimal diameter were measured at the narrowest axial slice between C6 and T2. Among 4660 tracheostomy patients, 300 met eligibility. Post-decannulation CT demonstrated a mean 13.6% reduction in tracheal area (−52.8 mm 2 ) and 11.2% reduction in diameter (−2.2 mm). Airway narrowing tended to be greater in patients undergoing tracheostomy for head and neck surgery. Tube sizes showed no clear pattern with airway reduction. Of 123 patients later re-intubated, 47.2% required a smaller endotracheal tube, and 12.2% needed multiple tube size attempts. Longitudinal analysis showed substantial inter-individual variability, with no clear temporal trend in recovery. In this multicentre cohort, surgical tracheostomy was followed by modest but measurable decreases in tracheal area and diameter after decannulation. These findings provide descriptive CT-based data on post-tracheostomy airway narrowing and highlight the need for further studies linking anatomical changes with functional airway outcomes.