Evaluation of the airway mechanics of modified toggle laryngoplasty constructs using a vacuum chamber airflow model

Objective: To evaluate the airway mechanics of modified toggle LP constructs in an airflow chamber model and compare these to the airway mechanics of standard LP constructs. Study design: Ex-vivo experimental study. Sample population: Fifty-one equine cadaveric larynges. Methods: Bilateral LP constructs were performed using a modified toggle (n = 23) or a standard (n = 21) LP technique. Constructs were tested in an airflow model before and after cyclic loading which was designed to mimic postoperative swallowing. The cross-sectional area (CSA), peak translaryngeal airflow (L/s), and impedance (cmH₂0/L/s) were determined and compared between LP constructs before and after cycling. Results: The mean CSA of the rima glottidis of the modified toggle LP constructs was 15.2 ± 2.6 cm² before and 14.7 ± 2.6 cm² after cyclic loading, and the mean CSA of the rima glottidis of the standard LP constructs was 16.4 ± 2.9 cm² before and 15.7 ± 2.8 cm² after cyclic loading. The modified toggle LP constructs had similar peak translaryngeal impedance before and after cyclic loading (p =.13); however, the standard LP constructs had higher peak translaryngeal impedance after cyclic loading (p =.02). Conclusion: The modified toggle and standard LP constructs had comparable airway mechanics in an ex-vivo model. Clinical significance: Further investigation is warranted to determine the extent to which the modified toggle LP technique restores normal airway function in horses with RLN.