Homologous collagen substances for vocal fold augmentation

Area of Science:

• Laryngology
• Biomaterials Science
• Regenerative Medicine

Background:

• Dysphonia due to glottic insufficiency is a challenging clinical issue.
• Homologous collagen compounds present a potential therapeutic option for voice disorders.
• Understanding optimal placement and effects of collagen grafts is crucial for effective treatment.

Purpose of the Study:

• To evaluate collagen graft placement sites and volumes in human vocal folds.
• To assess the impact of superficial vocal fold implants on laryngeal vibratory patterns and adduction forces.
• To determine the host response to different forms of cadaveric collagen.

Main Methods:

• Cadaveric larynges were injected with collagen compounds to assess placement and volume.
• Laryngeal vibratory patterns and adduction forces were manipulated and measured before and after collagen injection.
• A nude mouse model was utilized to evaluate host response to collagen implants.

Main Results:

• Collagen compounds were reliably injected into the superficial lamina propria and thyroarytenoid (TA) muscle.
• Injection into the TA muscle significantly reduced the force needed for vocal fold adduction without impairing vibration.
• Both AlloDerm® and Dermalogen® showed good tolerability in mice with minimal inflammation and host integration.

Conclusions:

• Homologous collagen can be safely injected into the human larynx, particularly the TA muscle.
• TA muscle injections effectively reduce the force required for phonation with minimal impact on vocal fold vibration.
• These collagen materials demonstrate good tolerability and persistence, supporting further clinical investigation for dysphonia.