Currently available silicone and metallic stents for tracheal stenosis are associated with problems of granulations, mucus trapping, and difficult removals. Our aim was to develop a novel bioabsorbable tracheal stent with mitomycin C (MMC) drug elution to circumvent such problems.
A randomized animal study.
Twenty-five rabbits were randomly assigned into five test groups: 1) controls (without stent), 2) silicone tubular stents (commercially available currently); 3) bioabsorbable helical stents; 4) bioabsorbable tubular stents; and 5) bioabsorbable tubular stents with MMC. Weekly tracheal endoscopy to document granulation, mucus plugging, and extent of tracheal stenosis was performed for 12 weeks. One rabbit was euthanized every 3 weeks for histological analysis of the trachea. In vitro MMC-release profiles in conditions mimicking tracheal conditions were studied.
The bioabsorbable tubular stents with 0.1 mg MMC drug elution performed the best, with the least mucus trapping and airway obstruction due to tracheal stenosis. Tracheal stenosis was most significant for the bioabsorbable helical stents, followed by the control group without stent, the group of bioabsorbable tubular stents, and then the silicone stents. After 12 weeks, tracheal stenosis for the bioabsorbable tubular stents with MMC was only half that of the silicone stents.
This study reports on the development of a novel bioabsorbable tracheal stent with sustained MMC drug elution for preventing tracheal stenosis. Further studies are warranted to optimize stent design and drug dosage.