Purpose: Ultrasonography of the airway has potential as an alternative, non-invasive, method to monitor patients with subglottic stenosis in an outpatient setting. This prospective, interventional, double-blinded study aimed to correlate ultrasound-based and laryngoscopy-based subglottic stenosis assessment in adults.
Methods: The study was conducted between July 2020 and March 2021 at a tertiary referral center. Consecutive adult patients with subglottic stenosis were evaluated using airway ultrasonography 1 day prior to scheduled laryngoscopy. The radiologist was blinded to the preoperative endoscopic findings, and the primary surgeon was blinded to the ultrasonographic measurements. The intraoperative subglottic diameter was defined as the outer diameter of an endotracheal tube passing through the subglottis without producing an air leak.
Results: Sixteen patients (11 females; age range, 17-66 years; mean = 44.06, SD = 12.79) were included. The ultrasonographic subglottic diameter ranged from 5.20 mm to 8.00 mm (mean = 6.24 mm, SD = 0.90). In 15 of 16 patients, the diameter difference between the ultrasonographic and intraoperative measurements ranged from -0.80 mm to 0.30 mm (mean = -0.20 mm, SD = 0.35). However, patient 6 had a difference of - 2.10 mm between the two measurements, which was attributed to thick laryngotracheal secretions interfering with the ultrasonographic air shadow. Data analysis of all 16 patients showed a statistically significant correlation between the readings obtained by the two techniques (r = 0.84, P = 0.000051).
Conclusion: This study found a significant correlation between ultrasonography-based and laryngoscopy-based subglottic stenosis assessment in adult patients. It provides a basis for an alternative and potentially reliable method to monitor patients with subglottic stenosis.
Keywords: Airway imaging; Subglottic diameter; Ultrasonography.
© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.