Ex Vivo Perfused Larynx Model of Phonation: Preliminary Study

Abstract

Objectives: Although excised laryngeal models and physical models of the larynx are important in the study of laryngeal dynamics, they cannot be used to study the influence of neuromuscular contraction on vocal fold vibration, especially with regard to the thyroarytenoid muscle. Our aim was to develop an ex vivo larynx model of phonation, and combine the benefits of the in vivo and excised laryngeal models to the ex vivo situation. Methods: Three canine larynges were surgically removed and perfused ex vivo with modified Krebs-Henseleit reperfusion solution. The laryngeal nerves were stimulated, and an assessment of neuromuscular viability, phonation, and vocal fold vibration was made. Results: Neuromuscular stimulation, phonation, and experimental manipulation were possible for several hours after the onset of ex vivo perfusion. Repeatable periodic phonation in short bursts was achieved. Perfusion appears critical to maintain ex vivo viability, as adductory force was almost immediately lost upon cessation of ex vivo perfusion. Conclusions: The ex vivo larynx model has the potential to facilitate the measurement of glottal variables in a neuromuscularly correct model. We propose that the further development of this laryngeal model may be useful in the study of laryngeal dynamics, particularly when invasive measurements, such as that of glottal exit flow, are required.