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.