Hylan B gel restores structure and function to laser-ablated canine vocal folds.

OBJECTIVES We evaluated cross-linked hyaluronic acid (hylan B gel) as a scaffold for tissue regeneration and mucosal wave restoration in carbon dioxide laser-ablated canine vocal folds. METHODS Five beagles underwent stroboscopy before ablation of the left vocal fold with a carbon dioxide laser. Four weeks later, stroboscopy was repeated before and after submucosal injection of hylan B gel into the left vocal fold of 4 animals and of saline solution in 1 animal. Stroboscopy was repeated 12 weeks later, and histologic analysis was performed. RESULTS Four weeks after laser ablation, all animals had soft tissue defects and absence of mucosal waves. Hylan B injection restored mucosal waves, and saline injection did not. Twelve weeks after injection, hylan B-injected larynges had tissue regeneration and mucosal waves, and the saline-injected larynx had neither. Histology showed regenerated lamina propria with residual foci of hylan B in the hylan B-injected larynges and dense submucosal scar in the saline-injected animal. CONCLUSIONS Submucosal hylan B gel injection in laser-ablated canine vocal folds restored tissue volume and mucosal waves and facilitated functional tissue regeneration over 12 weeks. Hylan B gel may have utility as a soft tissue scaffold for rehabilitation of phonatory function in vocal folds with lamina propria defects.