Histologic and Rheologic Characterization of Vocal Fold Scarring

Scarring of the vocal fold causes considerable dysphonia and presents significant treatment challenges. A rabbit model was developed to investigate the histologic ultrastructure and rheologic properties of the scarred vocal fold lamina propria. Eleven rabbit larynges were scarred by means of forcep biopsy. Sixty days postoperatively, the rabbits were sacrificed and their vocal folds were harvested. Histological analysis of the scarred and normal lamina propria was completed for collagen, procollagen, elastin, and hyaluronic acid. Linear viscoelastic shear properties of the tissues were also measured, including elastic shear modulus and dynamic viscosity. Compared to normal vocal fold lamina propria, scarred tissues demonstrated significantly less collagen, an increase in procollagen, and a decrease in elastin. Rheologically, both elastic shear modulus and dynamic viscosity were significantly higher for the scarred tissues. Increased stiffness and viscosity do not appear to result from an increase in collagen, but rather appear to be related to the presence of new, disorganized collagen scaffolding. Results are interpreted in terms of the possible role of interstitial proteins in the etiology of increased stiffness and viscosity, which requires further investigation. This animal model should allow for systematic future investigations of vocal fold scarring and its treatment.     

Direct Autogenous Fat Implantation for Augmentation of the Vocal Folds

This report examines the results of autogenous fat implantation into paralyzed or flaccid vocal folds in 23 patients. No complications were encountered in any of these patients and very satisfactory voice improvement was achieved in every case. The voice improvement achieved initially has been sustained for one to four years in all patients but one, whose underlying disease process progressed and worsened the voice.     

Comparison of Telomere Length of Vocal Folds With Different Tissues: A Physiological Measurement of Vocal Senescence

The objective of this article is to determine telomere length, a measure of biological age, in true vocal fold (TVF), false vocal fold (FVF), and five other tissue types, to ascertain whether there is tissue-specific telomere shortening. The study design is that of a prospective, basic science study. Tissue samples were obtained from the TVF, FVF, skin from the back of hand, skin from thigh, aorta, blood, and bone marrow from 12 patients ages 54 to 76 years. Genomic DNA was isolated from each sample, and telomere lengths were calculated with real-time polymerase chain reaction. In our small age group, age was not significantly associated with telomere length across tissue types, nor were there any linear correlations within tissue types and age. Controlling for age, significant differences were found between the following tissues: aorta and blood (P < 0.000), aorta and bone marrow (P = 0.033), aorta and FVF (P = 0.015), aorta and hand skin (P = 0.004), blood and thigh skin (P = 0.012), and blood and TVF (P = 0.048). A significant linear correlation between telomere length and tissue type without considering donor age was established between bone marrow and hand skin (P < 0.05, R2 = 0.766), thigh skin and hand skin (P < 0.01, R2 = 0.926), TVF and blood (P < 0.01, R2 = 0.836), and thigh skin and TVF (P < 0.05, R2 = 0.624). Our findings indicate that surrogate tissue for measurement of telomere length of TVF includes FVF, bone marrow, skin, and aorta. These findings have implications for understanding vocal fold aging at the cellular level.