Vocal Fold Injury Produces Similar Biomechanical Outcomes in Male and Female Rabbits

Area of Science:

• Otolaryngology
• Vocal Fold Physiology
• Comparative Anatomy

Background:

• Sex differences in physiological responses to injury are well-documented across organ systems.
• However, such differences in the larynx, particularly concerning vocal fold injury, remain largely undefined.
• Understanding these differences is crucial for targeted therapeutic strategies.

Purpose of the Study:

• To establish an endoscopic rabbit model for inducing vocal fold injury.
• To comparatively analyze the structural and functional sequelae of this injury in male versus female rabbits.
• To investigate potential sex-based disparities in vocal fold healing and mechanics.

Main Methods:

• A unilateral endoscopic cordectomy was performed on four rabbits (two male, two female).
• Post-operative assessment at 8 weeks included excised larynx phonation analysis using high-speed videography and kymography.
• Vocal fold tissue elasticity was quantified using Young's modulus measurements via indentation.

Main Results:

• The developed rabbit model successfully induced vocal fold scarring.
• Scarred vocal folds in both sexes exhibited increased tissue stiffness (Young's modulus) compared to uninjured contralateral folds.
• No significant sex-based differences were observed in fundamental frequency, glottal closure patterns, or vocal fold oscillation symmetry.

Conclusions:

• An effective endoscopic model for studying vocal fold scarring in rabbits has been established.
• The study found comparable structural and vibrational outcomes between male and female rabbits following vocal fold injury.
• These findings suggest that sex may not be a significant factor in the immediate biomechanical response to this specific type of vocal fold trauma.