Ex vivo biomechanical stability of 5 cricoid-suture constructs for equine laryngoplasty

Abstract

Objective: To determine the biomechanical properties of 5 suture constructs in the equine cricoid under cyclic loading and load to failure testing.

Study design: Ex vivo study.

Samples: Seventy-five equine cadaver larynges.

Methods: Each larynx was implanted with 1 of 5 cricoid-suture constructs. The standard laryngoplasty, where a suture is passed once through the cricoid, including its caudal edge, was used in 2 constructs: 1 with 5 USP Ethibond (ES) and 1 with 2 mm Fibertape (FS). In the third construct, the 2 mm Fibertape was passed twice through the cricoid including its caudal edge (Double Loop-DL). Constructs 4 and 5 used 2 mm Fibertape in a U-shaped loop passed through the cricoid but excluding its caudal edge. One construct was supported with a metallic button (MB) on the caudo-ventral aspect of the cricoid while the other included only the U-shaped loop (U). Constructs were subjected to cyclic loading and to single cycle to failure. Reduction of the left-to-right arytenoid angle quotient (LRQ), suture migration, and load at failure were compared.

Results: LRQ reduction after cyclic loading was lower in MB and U than ES constructs. During cyclic loading, suture migration was reduced in MB, U, and DL compared to ES constructs. Mean load at failure was lower in FS and U than in ES constructs.

Conclusion: Loss of abduction after equine laryngoplasty may be reduced and pullout forces increased by applying a MB construct in the cricoid cartilage. In vivo testing is required to verify these results.