In vitro mechanical testing of braided polyurethane elastic fiber and braided polyester for equine laryngoplasty.
Authors: Willsallen Hadley, Heller Jane, Kark Lauren, Hilbert Bryan J
Journal: Veterinary surgery : VS
Summary
# Editorial Summary: Laryngoplasty Suture Materials—Mechanical Performance in Equine Cadaver Models Laryngeal hemiplegia remains a significant performance-limiting condition in horses, and laryngoplasty procedures commonly employ suture materials anchored through the arytenoid cartilage to maintain airway patency. This in vitro study compared two braided materials—polyurethane elastomer (Lycra) and polyester (Ethibond)—to evaluate their mechanical suitability for this application. Using thirty arytenoid muscular processes from fifteen equine cadaver larynges, researchers subjected both materials to cyclic loading (25–50 N) followed by failure testing, whilst isolated suture loops underwent identical cycling plus creep testing protocols. The results revealed a critical trade-off between material properties. Lycra prostheses pulled through the cartilage at substantially lower failure loads (95.9 ± 23.4 N versus Ethibond's 155.2 ± 24.4 N, *P* = 0.0041) and demonstrated greater slippage during cyclic testing (*P* = 0.015)—a concerning finding suggesting reduced cartilage-anchoring security. However, when isolated as suture loops without the cartilage interface, Lycra demonstrated superior tensile strength (233.0 ± 38.7 N versus 201.6 ± 47.4 N, *P* = 0.042). Both materials showed significantly greater displacement with Lycra, indicating greater elasticity throughout testing. For practitioners, these findings suggest that whilst Lycra's inherent strength as suture material is advantageous, its greater compliance and poorer cartilage interface retention may compromise long-term prosthesis security
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Practical Takeaways
- •Ethibond™ appears mechanically superior for laryngoplasty as it resists pull-through of the arytenoid cartilage better than Lycra®, which may translate to improved long-term surgical outcomes
- •The greater displacement properties of Lycra® could result in prosthesis loosening and recurrence of clinical signs despite theoretical advantages in suture loop strength
- •Material selection for laryngoplasty should prioritize resistance to pull-through forces through cartilage rather than isolated suture strength, based on these biomechanical findings
Key Findings
- •Lycra® prostheses pulled through arytenoid cartilage at significantly lower loads (95.9 N) compared to Ethibond™ (155.2 N), P=0.0041
- •Lycra® showed greater displacement than Ethibond™ both with and without cartilage interface (P<0.001 and P<0.002)
- •Lycra® isolated suture loops paradoxically failed at higher loads (233.0 N) than Ethibond™ loops (201.6 N), P=0.042
- •Lycra® prostheses pulled through cartilage in significantly more cyclic fatigue tests than Ethibond™ (P=0.015)