In vitro model for testing novel implants for equine laryngoplasty

Area of Science:

• Equine respiratory physiology
• Biomechanical engineering
• Surgical technique development

Background:

• Laryngoplasty is a surgical procedure to correct laryngeal hemiplegia in horses.
• Maximal exercise in horses generates significant airflow and negative pressures within the larynx.
• Existing in vitro models may not accurately replicate the dynamic pressures and flows experienced during maximal exercise.

Purpose of the Study:

• To develop and validate an in vitro laryngeal model that mimics the airflow and pressures horses experience during maximal exercise.
• To create a platform for testing and comparing different laryngoplasty techniques.

Main Methods:

• Cadaveric equine larynges (n=10) were utilized.
• A bilateral prosthetic laryngoplasty was performed using #5 Fiberwire suture for maximal arytenoid abduction.
• Larynges were subjected to static and dynamic (2 Hz) airflow in a flow chamber, with tracheal and chamber pressures recorded.

Main Results:

• The model generated static inspiratory tracheal pressures of -33.0+/-0.98 mm Hg at 54.48+/-1.8 L/s.
• Dynamic conditions at 2 Hz produced peak inspiratory tracheal pressures of -35.54+/-1.6 mm Hg at 51.65+/-2.3 L/s.
• The generated pressures and flows closely approximated published physiological values for horses at maximal exercise.

Conclusions:

• The developed in vitro model effectively replicates the inspiratory pressures and airflows horses encounter during maximal exercise.
• This model provides a valuable tool for evaluating existing laryngoplasty techniques and advancing the development of new surgical methods.