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Mok A, Allen J, Haney MM, Deninger I, Ballenger B, Caywood V, Osman KL, Zitsch B, Hopewell BL, Thiessen A, Szewczyk M, Ohlhausen D, Newberry CI, Leary E, Lever TE. A Surgical Mouse Model for Advancing Laryngeal Nerve Regeneration Strategies. Dysphagia 2019; 35:419-437. [PMID: 31388736 DOI: 10.1007/s00455-019-10045-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 02/06/2019] [Accepted: 07/31/2019] [Indexed: 01/16/2023]
Abstract
Iatrogenic recurrent laryngeal nerve (RLN) injury is a morbid complication of anterior neck surgical procedures. Existing treatments are predominantly symptomatic, ranging from behavioral therapy to a variety of surgical approaches. Though laryngeal reinnervation strategies often provide muscle tone to the paralyzed vocal fold (VF), which may improve outcomes, there is no clinical intervention that reliably restores true physiologic VF movement. Moreover, existing interventions neglect the full cascade of molecular events that affect the entire neuromuscular pathway after RLN injury, including the intrinsic laryngeal muscles, synaptic connections within the central nervous system, and laryngeal nerve anastomoses. Systematic investigations of this pathway are essential to develop better RLN regenerative strategies. Our aim was to develop a translational mouse model for this purpose, which will permit longitudinal investigations of the pathophysiology of iatrogenic RLN injury and potential therapeutic interventions. C57BL/6J mice were divided into four surgical transection groups (unilateral RLN, n = 10; bilateral RLN, n = 2; unilateral SLN, n = 10; bilateral SLN, n = 10) and a sham surgical group (n = 10). Miniaturized transoral laryngoscopy was used to assess VF mobility over time, and swallowing was assessed using serial videofluoroscopy. Histological assays were conducted 3 months post-surgery for anatomical investigation of the larynx and laryngeal nerves. Eight additional mice underwent unilateral RLN crush injury, half of which received intraoperative vagal nerve stimulation (iVNS). These 8 mice underwent weekly transoral laryngoscopy to investigate VF recovery patterns. Unilateral RLN injury resulted in chronic VF immobility but only acute dysphagia. Bilateral RLN injury caused intraoperative asphyxiation and death. VF mobility was unaffected by SLN transection (unilateral or bilateral), and dysphagia (transient) was evident only after bilateral SLN transection. The sham surgery group retained normal VF mobility and swallow function. Mice that underwent RLN crush injury and iVNS treatment demonstrated accelerated and improved VF recovery. We successfully developed a mouse model of iatrogenic RLN injury with impaired VF mobility and swallowing function that can serve as a clinically relevant platform to develop translational neuroregenerative strategies for RLN injury.
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Affiliation(s)
- Alexis Mok
- Department of Communication Science and Disorders, University of Missouri School of Health Professions, Columbia, MO, USA
| | - Jakob Allen
- Department of Medicine, University of Missouri School of Medicine, Columbia, MO, USA
| | - Megan M Haney
- Department of Veterinary Pathobiology, University of Missouri College of Veterinary Medicine, Columbia, MO, USA
| | - Ian Deninger
- Department of Otolaryngology - Head & Neck Surgery, University of Missouri School of Medicine, Columbia, MO, USA
| | - Brayton Ballenger
- Department of Otolaryngology - Head & Neck Surgery, University of Missouri School of Medicine, Columbia, MO, USA
| | - Victoria Caywood
- Department of Otolaryngology - Head & Neck Surgery, University of Missouri School of Medicine, Columbia, MO, USA
| | - Kate L Osman
- Department of Otolaryngology - Head & Neck Surgery, University of Missouri School of Medicine, Columbia, MO, USA
| | - Bradford Zitsch
- Department of Medicine, University of Missouri School of Medicine, Columbia, MO, USA
| | - Bridget L Hopewell
- Department of Otolaryngology - Head & Neck Surgery, University of Missouri School of Medicine, Columbia, MO, USA
| | - Aaron Thiessen
- Department of Otolaryngology - Head & Neck Surgery, University of Missouri School of Medicine, Columbia, MO, USA
| | - Marlena Szewczyk
- Department of Medicine, University of Missouri School of Medicine, Columbia, MO, USA
| | - Daniel Ohlhausen
- Department of Otolaryngology - Head & Neck Surgery, University of Missouri School of Medicine, Columbia, MO, USA
| | | | - Emily Leary
- Department of Orthopedic Surgery, University of Missouri School of Medicine, Columbia, MO, USA
| | - Teresa E Lever
- Department of Otolaryngology - Head & Neck Surgery, University of Missouri School of Medicine, Columbia, MO, USA. .,One Hospital Dr. MA314, Columbia, MO, 65212, USA.
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