Functional Remobilization Evaluation of the Paralyzed Vocal Cord by End‐to‐Side Neurorrhaphy in Rats

Abstract

Vocal cord paralysis cannot be treated by this microsurgical technique.

Novel Model to Assess Laryngeal Function, Innervation, and Reinnervation

“…The arytenoid cartilage and vocal processes dominate the glottal opening and may deceive an investigator into thinking that these are the entire true vocal folds. Coupled with anatomic dissection, endoscopic analysis of the larynx with a 30° endo- [16][17][18][19] The use of the suspension laryngoscope and 30° endoscope provided adequate visualization of the entire rat larynx.…”

“…A majority of published pictures of the rat larynx consist of pictures of the vocal processes similar to our Fig 3. [16][17][18][19] The use of the suspension laryngoscope and 30° endoscope provided adequate visualization of the entire rat larynx.…”

“…A majority of studies have provided pictures of the rat arytenoid cartilages and vocal processes, but not the true vocal folds. [16][17][18][19] The ratio of the length of the musculomembranous vocal folds to that of the vocal processes is quite different in humans, because the musculomembra-nous portions dominate the human glottal opening, in contrast to what is found in the rat larynx. Despite this difference, anatomic and muscle-staining studies support the use of the rat larynx for modeling human diseases.…”

Comparison of inhaled versus intravenous anesthesia for laryngoscopy and laryngeal electromyography in a rat model

“…Several anesthetics in experimental animal models have been used to perform safe, interpretable and reliable endoscopy and/or LEMG, but direct comparisons and proof of reproducibility are limited [ 13 – 17 , 27 – 32 ]. These included intraabdominal barbitone sodium [ 27 ], mixture of intramuscular ketamine hydrochloride and xylazine hydrochloride [ 14 , 15 , 30 ] intramuscular ketamine only [ 28 ], combination of inhaled isoflurane and intraperitoneal ketamine and xylazine [ 16 , 17 , 29 , 31 ], intraperitoneal/intravenous pentobarbital sodium [ 32 ], and isoflurane only [ 13 ]. With the exception of ketamine and isoflurane, none of these drugs are used in clinical practice.…”

“…Multiple intrinsic laryngeal muscles were described in the literature as a point for recording LEMG activity in both animals and humans. This includes thyroarytenoid [ 9 – 12 , 15 – 18 , 33 , 36 – 39 , 44 – 49 ], cricothyroid [ 44 , 46 , 48 , 50 ], PCA [ 11 – 13 , 15 , 16 , 18 , 27 , 32 , 33 , 37 , 38 , 44 , 45 , 49 , 51 , 52 ] and lateral cricoarytenoid [ 15 ] either individually or in combination. The authors have selected the PCA muscle, as it’s the single laryngeal muscle responsible for vocal fold abduction.…”