In vitro mechanical evaluation of equine laryngeal tie-forward constructs prepared with different suture materials and placement patterns.

This research examines the mechanical properties of different laryngeal tie-forward (LTF) surgical approaches in horses, utilizing various suture materials and placement strategies. The study reveals that all the materials and methods tested are feasible for LTF procedures in live horses.

Study Methodology

• The researchers used larynges procured from 50 horse cadavers and 5 intact horse cadavers.
• They created in vitro LTF constructs with various types of sutures and techniques, including standard techniques using polyester and polyethylene sutures, modified techniques employing metallic implants and polyester or polyethylene sutures, and modified tie-off techniques with polyester sutures.
• Each type of construct was prepared 10 times.
• Maximal load (N) at failure and the mode of failure were compared among the constructs.
• The maximal load at failure of the in vitro LTF constructs was compared with the loads exerted on the sutures tightened to achieve rostral laryngeal advancement (forward movement of the larynx) in the intact cadaveric specimens.

Study Findings

• The study revealed that constructs prepared using a standard technique with polyethylene sutures demonstrated significantly higher pullout strength compared to those prepared using a modified technique with metallic implants and either polyester or polyethylene sutures.
• Between constructs prepared with a standard technique using either polyethylene or polyester sutures, there was no significant difference in the maximal load at failure. However, the mode of failure differed significantly between these two groups.
• The load to failure for all in vitro constructs was higher than the maximal load measured during a range of motion test in intact horse cadavers. This suggests that the in vitro constructs are mechanically stronger than what would be needed in a real-life scenario.

Study Conclusions

• The results suggest that it is possible to perform LTF procedures in live horses using any of the suture materials and techniques tested in this study.
• This has potential implications for veterinary surgeons considering the most effective suture material and technique for LTF procedures in horses.