Evaluation of injection augmentation treatment of hyaluronic acid based materials on rabbit vocal folds viscoelasticity.

The viscoelastic properties of vocal folds after injection of hyaluronic acid (hyaluronan, HA) based materials have been studied in an animal model (rabbit) six months after injection. The results indicate that the viscoelastic properties of the vocal folds injected with the HA based materials are similar to the healthy vocal folds (non-injected samples) used as control. Histological analysis has been also performed to investigate on the fate of the injected materials after six months from the implant. The HA based materials remain up to six months and they recruited fibroblasts that induce the ingrowth of new connective tissue resulting in an endogenous soft tissue augmentation. The HA based compounds are good candidate for further studies aimed at restoring/preserving the vibratory capacity of the vocal folds with injection treatment in glottal insufficiency.