Injection laryngoplasy is a typical treatment for glottal insufficiency. In Japan, silicone, collagen, autologous fat, calcium phosphate cement, and fibroblast growth factor have been used as injectable materials. However, none of these materials meets all of the ideal conditions, such as good biocompatibility, no absorbability, no migration, and ready formulation for easy injection.
Hyaluronic acid (HA) is a component of the extracellular matrix that plays a key role in tissue viscosity, shock absorption, wound healing, and space filling. Research into the role of HA in laryngology indicates that it has profound effects on the structure and viscoelastisity of vocal folds.
Injection laryngoplasty using HA of two different types of hardness was performed on 20 patients with glottal insufficiency. The results were compared preoperatively and at 1, 3, 6, 12, and 24 months postoperatively by acoustic and aerodynamic analyses and self-assessment (Voice Handicap Index-10 [VHI-10]).
For augmentation of vibrating part of vocal fold, injection laryngoplasty with soft type of HA was significantly effective for 12 months by Maximum Phonation Time (MPT), Pitch Perturbation Quotient (PPQ), and VHI-10.
For medialization of vocal fold, injection laryngoplasty using hard type of HA was significantly effective for 24 months by MPT.
