Prevention of vocal fold scarring by local application of basic fibroblast growth factor in a rat vocal fold injury model.

Objectives/Hypothesis: Vocal fold scarring, which causes severe hoarseness, is intractable. The optimal treatment for vocal fold scarring has not been established; therefore, prevention of scarring is important. The aim of this study was to clarify the effectiveness of basic fibroblast growth factor ( bFGF) for prevention of postsurgical vocal fold scarring. Study Design: Prospective animal experiments with controls. Method: The vocal folds of Sprague-Dawley rats were injured unilaterally or bilaterally after local application of a 10 mu L solution of bFGF. Larynges ware harvested for histological and immunohistochemical examination 2 months postoperation and for quantitative real-time polymerase chain reaction ( qRT-PCR) analysis 1 week postoperation. Results: Histological examination showed significantly increased hyaluronic acid and decreased deposition of dense collagen in the bFGF-treated group at 100 ng/10 mu L compared with the sham-treated group. Immunohistochemical examination showed significantly decreased collagen type III deposition in the bFGF-treated group at 100 ng/10 mu L compared with the sham-treated group. qRT-PCR revealed that hyaluronan synthase 2 ( Has2), Has3, and hepatocyte growth factor were upregulated in bFGF-treated groups compared with sham-treated group. Conclusion: The current results suggest that local application of bFGF at the time of injury has the potential to prevent vocal fold scarring. Preventive injection of bFGF could be applied at the time of phonomicrosurgery to avoid postoperative scar formation.