Evaluation of a prototype dynamic laryngoplasty system in vitro with an equine vacuum airflow system.
Authors: Ahern Benjamin J, Lukas Emily, Lam Kimberly, Wilke Emma, Bertin Francois-Rene, Van Eps Andrew, Franklin Samantha
Journal: Veterinary surgery : VS
Summary
# Editorial Summary Laryngeal hemiplegia remains a significant performance-limiting condition in horses, and whilst conventional laryngoplasty using suture fixation is well-established, this in vitro study explored whether a novel dynamic laryngoplasty system (DLPS)—essentially an implantable device capable of adjusting arytenoid abduction via applied pressure—could improve airway patency beyond what static suturing alone achieves. Ahern and colleagues tested ten equine larynges using a vacuum airflow model calibrated to 55 L/s (approximating high-intensity exercise), measuring translaryngeal impedance (TLI) as the primary indicator of airway resistance across varying suture lengths and DLPS activation pressures. Static laryngoplasty sutures reduced impedance substantially when shortened up to 6 mm, but additional tightening provided no further benefit; critically, activating the DLPS at 25 psi reduced TLI from 0.43 to 0.16 mm Hg/L/s—a 63% reduction—with no further improvement at maximal (50 psi) activation. For practitioners managing horses with laryngeal dysfunction, these findings suggest that a dynamic system capable of load-responsive arytenoid positioning could theoretically outperform static correction, potentially maintaining effective airway diameter across varying exercise intensities rather than being fixed at one point. Although this remains preliminary in vitro work, it warrants progression to in vivo trials to determine whether the DLPS could offer functional advantages over conventional laryngoplasty in clinical cases.
Read the full abstract on PubMed
Practical Takeaways
- •A dynamic laryngoplasty system shows promise for improving airway patency in laryngeal hemiplegia by reducing resistance during airflow, potentially offering better performance than static suture procedures alone
- •The system appears to reach optimal efficacy at moderate pressure levels (25 psi), suggesting clinical protocols should target this range rather than maximum pressurization
- •These in vitro findings warrant progression to in vivo and clinical trials to determine real-world applicability and whether dynamic systems outperform conventional static laryngoplasty techniques
Key Findings
- •Static suture shortening reduced translaryngeal impedance (TLI) up to 6 mm but provided no further benefit with additional shortening
- •Dynamic laryngoplasty system activation at 25 psi reduced TLI from 0.43 to 0.16 mm Hg/L/s (63% reduction)
- •Maximum psi activation (50 psi) provided no additional TLI reduction beyond 25 psi, suggesting optimal pressure threshold exists