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Veterinary surgery : VS2026; doi: 10.1111/vsu.70083

Functional and histopathologic evidence of laryngeal reinnervation using the spinal accessory nerve in horses.

Abstract: To evaluate functional and histopathologic outcomes of standing selective laryngeal reinnervation using the spinal accessory nerve (SAN) in horses with experimentally induced recurrent laryngeal neuropathy (RLN). Methods: Five Thoroughbred mares. Methods: Prospective cohort study. Methods: The horses underwent left recurrent laryngeal neurectomy followed 8 weeks later by selective laryngeal reinnervation using the SAN. Follow-up evaluations at 4.5, 6, 8, and 12 months included treadmill exercising endoscopy, ultrasonography of intrinsic laryngeal muscles, and percutaneous electrical stimulation of the SAN. Twelve months postoperatively, the horses were euthanized for macroscopic and histopathologic examination of the cricoarytenoideus dorsalis (CAD), cricoarytenoideus lateralis (CAL), sternomandibularis (SM), spinal accessory and recurrent laryngeal nerves. Results: Twelve months following laryngeal reinnervation, mean left-to-right quotient angle ratio (LRQ) recovered to 94% of predenervation values with no difference from the baseline (95% CI [90, 98]; p = .69). One horse exhibited a slower and incomplete recovery. Post-mortem examination confirmed successful spinal accessory nerve implantation in the left CAD muscle in all horses. Histopathologic examination revealed axonal regeneration of the spinal accessory nerve and reinnervation of the left lateral CAD muscle belly with fiber type grouping and a shift toward an increased proportion of type I fibers consistent with functional reinnervation. Conclusions: Selective laryngeal reinnervation using the spinal accessory nerve restored functional arytenoid abduction at exercise in 4/5 horses with experimentally induced RLN. Conclusions: In horses with RLN and mild to moderate CAD muscle atrophy, selective laryngeal reinnervation using the SAN represents a physiological and effective treatment option.
© 2026 American College of Veterinary Surgeons.
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Publication Date: 2026-02-18 PubMed ID: 41705478DOI: 10.1111/vsu.70083Google Scholar: Lookup
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APA
Campos Schweitzer A, Mespoulhes-Rivière C, Perkins JD, Ducharme NG, Piercy RJ, Lynch N, Rossignol F. (2026). Functional and histopathologic evidence of laryngeal reinnervation using the spinal accessory nerve in horses. Vet Surg. https://doi.org/10.1111/vsu.70083

Publication

Veterinary surgery : VS
ISSN: 1532-950X
NlmUniqueID: 8113214
Country: United States
Language: English

Researcher Affiliations

Campos Schweitzer, Ariane
  • Grosbois Equine Clinic, Boissy-Saint-Léger, France.
Mespoulhes-Rivière, Céline
  • National Veterinary School of Alfort, Equine Referral Hospital, Maisons-Alfort and Goustrainville, France.
  • Royal Veterinary College, Equine Referral Hospital, Hatfield, UK.
Perkins, Justin D
  • Royal Veterinary College, Equine Referral Hospital, Hatfield, UK.
Ducharme, Norm G
  • Equine Referral Hospital, Cornell University, Ithaca, New York, USA.
Piercy, Richard J
  • Royal Veterinary College, Equine Referral Hospital, Hatfield, UK.
Lynch, Nicola
  • Comparative Neuromuscular Diseases Laboratory, Royal Veterinary College, London, UK.
Rossignol, Fabrice
  • Grosbois Equine Clinic, Boissy-Saint-Léger, France.

Grant Funding

  • Sport Horse Research Foundation Inc.
  • European College of Veterinary Surgeons (ECVS)

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