Neuroanatomy of the equine dorsal cricoarytenoid muscle: surgical implications.
Authors: Cheetham J, Radcliffe C R, Ducharme N G, Sanders I, Mu L, Hermanson J W
Journal: Equine veterinary journal
Summary
# Neuroanatomy of the Equine Dorsal Cricoarytenoid Muscle: Surgical Implications Recurrent laryngeal neuropathy remains a significant performance-limiting condition in horses, yet surgical treatments have historically lacked the anatomical precision needed for optimal outcomes. Cheetham and colleagues undertook detailed neuroanatomical dissections of 31 equine larynges (25 subjected to gross dissection, with subsets analysed via histochemical staining and motor endplate mapping) to characterise the dorsal cricoarytenoid muscle's structure, innervation patterns and functional mechanics. Their key finding was the identification of two distinct neuromuscular compartments, each receiving separate innervation from the recurrent laryngeal nerve; electrical stimulation demonstrated that the lateral compartment produced significantly greater lateral displacement of the arytenoid cartilage (P<0.05), whilst the medial compartment tended to rotate it dorsally. This anatomical distinction directly informs surgical planning for reinnervation procedures and neuroprosthetic device development, allowing clinicians and researchers to target specific muscle compartments with greater precision and potentially improve functional outcomes in cases of recurrent laryngeal neuropathy.
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Practical Takeaways
- •Understanding the dual compartment anatomy is critical for surgeons planning reinnervation procedures or neuroprosthesis implantation for recurrent laryngeal neuropathy
- •The lateral compartment's superior role in increasing airway diameter may make it a priority target for surgical intervention in RLN cases
- •Knowledge of discrete motor endplate locations informs precise electrode or graft placement for functional restoration
Key Findings
- •The equine dorsal cricoarytenoid muscle contains two distinct neuromuscular compartments (NMC), each with independent innervation from separate recurrent laryngeal nerve branches
- •Lateral NMC stimulation produced significantly greater lateral arytenoid cartilage displacement than medial NMC (P<0.05)
- •Medial NMC stimulation tended to cause dorsal rotation of the arytenoid cartilage
- •Motor endplates were consistently located at the junction of the middle and caudal thirds of each NMC