Three-dimensional models of the equine larynx can be used to perform traditional measures of arytenoid abduction and permit the positioning of modeled implants to demonstrate the anatomic feasibility of placing a rigid implant across the cricoarytenoid joint.

The study is about developing 3D models of horse larynges to compare measurements and test the feasibility of implant placement in a particular joint. The researchers conducted tests involving a plausible surgical procedure for horses affected by recurrent laryngeal neuropathy.

Objective and Methodology

• The main goal of this study was to create three-dimensional (3D) models of equine larynges, which could be used to compare measurements of arytenoid abduction between different specimens and to examine the feasibility of placing an implant across the cricoarytenoid joint (CAJ), an important joint in the horse’s larynx.
• Cadaveric horse larynges were used in the study. CT scans were performed in neutral positions and with two arytenoid treatments: bilateral arytenoid abduction (ABD) and bilateral arytenoid abduction following left cricoarytenoid joint arthrotomy (ARTH), i.e., an incision into the joint.
• Soft tissue, cartilage, and luminal volume three-dimensional models were then generated from these scans. The models were used to measure various parameters including the cross-sectional area (CSA) of the rima glottidis – the space between the vocal cords, left-to-right quotient (LRQ) angles, arytenoid cartilage translation, articular contact area, and the length of modeled implants placed across the CAJ.

Results and Conclusion

• The results indicated that ARTH CSA was larger for actual laryngeal specimens than for 3D models. However, there was no difference in other measurements between treatment groups or between actual specimens and models.
• The study found that the articular contact area was sufficient for placing modeled implants across the CAJ, with a narrow range of implant lengths that could be accommodated across larynges, either with or without arthrotomy.
• Bearing these findings in mind, the authors conclude that their results justify further investigation into a computed tomography (CT)-guided, minimally invasive surgical procedure for the treatment of horses with recurrent laryngeal neuropathy (RLN) – a nervous system condition that affects their larynx.
• The authors suggest that future studies should evaluate the technical precision, biomechanical stability, and post-operative success rates of this new procedure in treating horses with RLN.