Effects of topically applied dexamethasone on mucosal wound healing using a drug-releasing stent

Abstract

Objective/hypothesis: Evaluation of the impact of continuously topically released dexamethasone using a drug-releasing stent on quality of regenerated mucosa after full thickness injury in the paranasal sinuses.

Study design: Prospective, controlled, randomized, double-blinded animal study.

Methods: Nineteen New Zealand white rabbits were subjected to surgery: via an external approach, a 4 mm circular wound was created on the medial side of the maxillary sinus. The wound was covered in a randomized fashion with either a silicone foil or a new drug releasing stent system. Twelve to 30 days later, the animals were killed and histology and electron microscopy were performed. One animal was used for baseline comparisons at day 0.

Results: No animals were lost due to infection or dislocation of the stent, leaving 18 animals for evaluation of postoperative healing quality. According to macroscopic examination, extent of granulations was smaller in the treatment group (dexamethasone: median 0 [95% confidence interval: 0.1-0.6]) than the silicone group (2 [1.5-2.3]; P < or = .05). Epithelial wound healing was complete in all specimens, whereas the stroma was significantly thinner in the dexamethasone-group (44 [37-60]; 178 [148-214]). Improved healing quality was achieved significantly more often on the treatment, than on the control side. Scanning electron microscopy revealed no difference between both groups.

Conclusions: Using a new drug-releasing stent system, dexamethasone efficiently decreases granulation formation and stroma thickness without impeding epithelial differentiation. Therefore, the use of this system may be of value to decrease restenosis rates in selected patients after frontal sinus surgery.