Age-related voice change is characterized as weak, harsh, and breathy. These changes are caused by histologic alteration of the lamina propria of the vocal fold mucosa as well as atrophy of the thyroarytenoid muscle. Several therapeutic strategies involving laryngeal framework surgery and injection laryngoplasty have been tried, but effects have been limited. Vocal function exercises (VFE) have been used to treat age-related vocal fold atrophy although the effectiveness has been shown with limited analysis. The present study aims to determine the effectiveness of VFE for the treatment of aged atrophy using multidimensional analysis. This is a retrospective study. Sixteen patients with vocal fold atrophy aged 65-81 years underwent voice therapy using VFE. Six patients with vocal fold atrophy aged 65-85 years were involved as a historical control group. The grade, roughness, breathiness, asthenia, strain (GRBAS) scale, stroboscopic examinations, aerodynamic assessment, acoustic analysis, and Voice Handicap Index-10 (VHI-10) were performed before and after VFE. Normalized mucosal wave amplitude (NMWA), normalized glottal gap (NGG), and bowing index (BI) were measured by image analysis during stroboscopic examinations. After VFE, significant improvements were shown in GRBAS, maximum phonation time, jitter, NMWA, NGG, and VHI-10 although BI has not changed significantly. There were no significant improvements in the historical control. The data suggest that VFE produces significant improvement in subjective, objective, and patient self-evaluation and deserves further attention as a treatment for aged atrophy of the vocal fold. It was also suggested that VFE does not improve the vocal fold bowing but may improve muscular function during voicing.
Transforming growth factor (TGF)-β1 and TGF-β3 have been reported to exert differential effects on wound healing, and possibly even account for tissue-specific differences in scar formation. Scarring is particularly detrimental in the vocal fold mucosa (VFM), where destruction of the native extracellular matrix causes irreparable biomechanical changes and voice impairment. Here, in a series of in vitro and in vivo experiments, we identified differences in TGF-β1 and TGF-β3 transcription and immunolocalization to various cell subpopulations in naïve and injured rat VFM, compared with oral mucosa (which undergoes rapid healing with minimal scar) and skin (which typically heals with scar). Treatment of cultured human vocal fold fibroblasts with TGF-β3 resulted in less potent induction of profibrotic gene transcription, extracellular matrix synthesis and fibroblast-myofibroblast differentiation, compared with treatment with TGF-β1 and TGF-β2. Finally, delivery of exogenous TGF-β3 to rat VFM during the acute injury phase modulated the early inflammatory environment and reduced eventual scar formation. These experiments show that the TGF-β isoforms have distinct roles in VFM maintenance and repair, and that TGF-β3 redirects wound healing to improve VFM scar outcomes in vivo.
18 November 2015 in Science Translational Medicine
Objectives/Hypothesis: Therapeutic challenges exist in the management of vocal fold scarring. We have previously demonstrated the therapeutic potential of hepatocyte growth factor (HGF) in the management of acute phase vocal fold scarring using a novel hydrogel‐based HGF drug delivery system (DDS). However, the effect of HGF on matured vocal fold scarring remains unclear. The current study aims to investigate the effect of HGF‐DDS on chronic vocal fold scarring using a canine model.Study Design: Animal model.Methods: Vocal folds from eight beagles were unilaterally scarred by stripping the entire layer of the lamina propria; contralateral vocal folds were kept intact as normal controls. Six months after the procedures, hydrogels (0.5 mL) containing 1 μg of HGF were injected into the scarred vocal folds of four dogs (HGF‐treated group). Hydrogels containing saline solution were injected into the other four dogs (sham group). Histological and vibratory examinations on excised larynges were completed for each group 9 months after the initial surgery.Results: Experiments conducted on excised larynges demonstrated significantly better vibrations in the HGF‐treated group in terms of mucosal wave amplitude. Although phonation threshold pressure was significantly lower in the HGF‐treated group compared with the sham group, no significant differences were observed in the normalized glottal gap between HGF‐treated and sham groups. Histological examinations of the HGF‐treated vocal folds showed reduced collagen deposition and less tissue contraction with favorable restoration of hyaluronic acid.Conclusions: Results suggest that administration of HGF may have therapeutic potential in the treatment of chronic vocal fold scarring. Laryngoscope, 2010