Permeability of canine vocal fold lamina propria

Abstract

Objective Determine the permeability of excised canine vocal fold lamina propria Study Design Basic Science Methods Vocal folds were excised from canine larynges and mounted within a device to measure the flow of 0.9% saline through the tissue over time. The resultant fluid volume displaced over time was then used in a variation of Darcy’s law to calculate the permeability of the tissue. Permeability was found through each anatomical plane of the vocal fold, with 5 samples per plane. Permeability was also found for lamina propria stretched to 10%, 20%, and 30% of initial length to determine the effects of tensile strain on permeability, with 5 samples per level of strain. Results Permeability was found to be 1.40×10−13 m3s/kg through the sagittal plane, 1.00×10−13 m3s/kg through the coronal plane, and 4.02×10−13 m3s/kg through the axial plane. It was significantly greater through the axial plane than both the sagittal (p=0.025) and coronal (p=0.009) planes. Permeability under strain through the sagittal plane was found to be 1.94×10−13 m3s/kg under 10% strain, 3.35×10−13 m3s/kg under 20% strain, and 4.80×10−13 m3s/kg under 30% strain. The permeability significantly increased after 20% strain (p<0.05). Conclusion Permeability in canine vocal fold lamina propria was found to be increased along the anterior-posterior axis, following the length of the vocal folds. This may influence fluid distribution within the lamina propria during and after vibration. Similarly, permeability increased after 20% strain was imposed on the lamina propria, and may influence vocal fold dynamics during certain phonation tasks.

A Computational Study of Vocal Fold Dehydration During Phonation

“…Three sets of vocal fold permeability coefficients and three sets of epithelium permeability coefficients were considered. Due to the lack of experimental data of epithelial permeability in human, the epithelium permeability coefficients were chosen based on measured permeability through the coronal plane of the lamina propria in an excised canine model [29]. Although the permeability may increase during vibration [29], for simplicity, in this study all permeability coefficients were kept constant during the 5-min phonation.…”

“…Due to the lack of experimental data of epithelial permeability in human, the epithelium permeability coefficients were chosen based on measured permeability through the coronal plane of the lamina propria in an excised canine model [29]. Although the permeability may increase during vibration [29], for simplicity, in this study all permeability coefficients were kept constant during the 5-min phonation. Because the collagen, elastin, and muscle fibers within the vocal folds are aligned primarily along the AP direction [15], the permeability coefficient κ vf _ x was set to be larger than those in other directions κ vf _ y and κ vf _ z .…”

A Method to Administer Agents to the Larynx in an Awake Large Animal

“…Isotonic saline is used as a therapeutic for individuals with voice problems secondary to inhaling desiccated air or Sjogren's syndrome (Tanner et al, 2010;Tanner, Roy, & Merrill, 2013). Isotonic saline preserves vocal fold hydration homeostasis by maintaining the transepithelial ionic balance (Sivasankar & Fisher, 2007) and is routinely used in ex vivo phonation studies to keep the vocal fold hydrated at baseline (Meyer, Kvit, Devine, & Jiang, 2015;Meyer, McAvoy, & Jiang, 2013). Isotonic saline is also the gold standard for testing and validating new techniques that can be applied to understand laryngeal pathophysiology (Jungheim et al, 2016).…”

A computational study of vocal fold dehydration during phonation

“…Due to the lack of experimental data of epithelial permeability in human, the epithelium permeability coefficients were chosen based on measured permeability through the coronal plane of the lamina propria in an excised canine model [29]. Although the permeability may increase during vibration [29], for simplicity, in this study all permeability coefficients were kept constant during the 5-min phonation. Because the collagen, elastin, and muscle fibers within the vocal folds are aligned primarily along the AP direction [15], the permeability coefficient κ vf_x was set to be larger than those in other directions κ vf_y and κ vf_z .…”