Pilot Study to Assess the Use of Ultrasound in Evaluating the Abnormal Pediatric Airway

Point-of-care ultrasound-guided submucosal paclitaxel injection in tracheal stenosis model

Background and Objectives

Transcutaneous point-of-care ultrasound (POCUS) is a good tool to monitor the trachea in many clinical practices. The aim of our study is to verify the feasibility of POCUS-guided submucosal injection as a potential drug delivery method for the treatment of tracheal stenosis.

Materials and methods

The inner wall of the trachea was monitored via a bronchoscope during the POCUS-guided submucosal injection of methylene blue in fresh ex vivo porcine trachea to evaluate the distribution of methylene blue. The feasibility and eficacy of POCUS-guided submucosal injection were evaluated in a tracheal stenosis rabbit model. Animals were divided into sham group, tracheal stenosis group, and treatment group. Ten days after the scraping of the tracheal mucosa or sham operation, POCUS-guided submucosal injection of paclitaxel or saline was performed. Seven days after the submucosal injection, the trachea was assessed by cervical computed tomography (CT) scan and ultrasound.

Results

The distribution of methylene blue in trachea proved the technical feasibility of POCUS-guided submucosal injection. CT evaluation revealed that the tracheal stenosis index and the degree of tracheal stenosis increased significantly in the stenosis group, while POCUS-guided submucosal injection of paclitaxel partially reversed the tracheal stenosis. POCUS-guided submucosal injection of paclitaxel also decreased the lamina propria thickness and collagen deposition in the stenosed trachea.

Conclusion

POCUS-guided submucosal paclitaxel injection alleviated tracheal stenosis induced by scraping of the tracheal mucosa. POCUS-guided submucosal injection might be a potential method for the treatment of tracheal stenosis.

Correlation of airway ultrasonography and laryngoscopy findings in adults with subglottic stenosis: a pilot study

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.