Hyaluronan levels in acute vocal fold scar

OBJECTIVES/HYPOTHESIS: The objective was to measure the level of hyaluronan during the first 15 days after vocal fold biopsy in a rabbit model. STUDY DESIGN: Experimental, nonrandomized prospective study. METHODS: Twenty-eight rabbits underwent unilateral vocal fold biopsy. The contralateral vocal fold was preserved as a control sample. On days 3, 5, 10, and 15 after biopsy, hyaluronan levels in the injured and normal vocal folds were measured immunohistologically and with an ELISA assay. RESULTS: Hyaluronan levels in the injured vocal fold were lowest on day 3 and highest on day 5 after injury. Statistical analysis revealed that the injured vocal fold demonstrated significantly lower levels of hyaluronan on day 3 than on days 5, 10, and 15. On day 5, the injured vocal fold demonstrated significantly greater levels of hyaluronan than those observed on days 3, 10, and 15. Compared with the normal vocal fold, the injured vocal fold demonstrated significantly lower levels of hyaluronan on days 3, 10, and 15. No differences were observed between the injured and normal vocal fold on day 5, when the hyaluronan level was maximized in the injured vocal fold. CONCLUSION: Maximizing hyaluronan levels in the early stages of wound repair may have therapeutic potential for decreasing the incidence of vocal fold scar. Decreased hyaluronan levels may provide a less than optimal environment for normal tissue regeneration and may contribute to the formation of scar tissue in vocal fold lamina propria.