Histologic Study of Acute Vocal Fold Wound Healing after Corticosteroid Injection in a Rabbit Model

Objectives: Injectable corticosteroids have been used in phonosurgery to prevent scarring of the vocal fold because of their effects on wound healing, and to ensure better voice quality. We histologically evaluated the effects of dexamethasone sodium phosphate infiltration on acute vocal fold wound healing in rabbits 3 and 7 days after surgically induced injury by quantification of the inflammatory reaction and collagen deposition. Methods: A standardized surgical incision was made in the vocal folds of 12 rabbits, and 0.1 mL dexamethasone sodium phosphate (4 mg/mL) was injected into the left vocal fold. The right vocal fold was not injected and served as the control. The larynges were collected 3 and 7 days after surgery. For histologic analysis, the vocal folds were stained with hematoxylin-eosin for quantification of the inflammatory response and with picrosirius red for quantification of collagen deposition. Results: There was no quantitative difference in the inflammatory response between vocal folds injected with the corticosteroid and control vocal folds. However, the rate of collagen deposition was significantly lower in the corticosteroid-treated group at 3 and 7 days after injury (p = 0.002). Conclusions: The present results suggest that dexamethasone reduces collagen deposition during acute vocal fold wound healing.