Phrenic Nerve Reinnervation of the Cat's Larynx: A New Technique with Proven Success

1993 ◽  
Vol 102 (11) ◽  
pp. 837-842 ◽  
Author(s):  
Patrick J. Doyle ◽  
Brian D. Westerberg ◽  
Douglas B. Chepeha ◽  
Dietrich W. F. Schwarz
Keyword(s):  
Vocal Cord ◽  
Fibrin Glue ◽  
Phrenic Nerve ◽  
Retrograde Labeling ◽  
Phrenic Motoneurons ◽  
Posterior Cricoarytenoid Muscle ◽  
Complete Failure ◽  
A New Technique ◽  
Posterior Cricoarytenoid ◽  
Nerve Trauma

Reinnervation of the posterior cricoarytenoid muscle (PCA) should provide vocal cord abduction on inspiration, and passive adduction to enable phonation. Previous investigators have shown that reinnervation is possible, but results have not been clinically encouraging. When reinnervation was successful, the question remained whether it was provided by the transplanted nerve or by the ingrowth of adjacent nerves. In this study the phrenic nerve was transplanted directly into the PCA in a series of 12 cats. Fibrin glue was used to overcome nerve trauma and to prevent retraction of the nerve from the PCA. Laryngoscopy, electromyography, and retrograde labeling of the phrenic motoneurons provided evidence of functional reinnervation in 9 cats. Partial or complete failure in the remaining 3 was due to retraction of the nerve from the muscle. These results appear to justify trials of the procedure in humans.

Endoscopic Laser Medial Arytenoidectomy for Airway Management in Bilateral Laryngeal Paralysis

1993 ◽  
Vol 102 (2) ◽  
pp. 81-84 ◽  
Author(s):  
Roger L. Crumley
Keyword(s):  
Vocal Cord ◽  
Phrenic Nerve ◽  
Carbon Dioxide Laser ◽  
Recent Experience ◽  
Posterior Commissure ◽  
Laryngeal Paralysis ◽  
Nerve Transfers ◽  
Posterior Cricoarytenoid Muscle ◽  
Endoscopic Laser ◽  
Posterior Cricoarytenoid

A review of our recent experience in patients with bilateral laryngeal paralysis is described. While we continue to use phrenic nerve transfers in patients with mobile arytenoids, patients with fixed arytenoids generally require some sort of vocal cord lateralization, either by arytenoidectomy and arytenoidopexy or by partial vocal cord resection. The endoscopic laser medial arytenoidectomy is a convenient and effective method for opening the posterior glottic airway. One arytenoid is reduced medially with the carbon dioxide laser. After about 3 months the opposite arytenoid can be treated similarly, if necessary. The procedure does not appear to affect arytenoid mobility, as the posterior commissure mucosa and underlying interarytenoid muscle are protected and hence unaffected by the procedure. Those patients with at least one mobile arytenoid cartilage are candidates for posterior cricoarytenoid muscle reinnervation. Although ansa cervicalis and phrenic nerve techniques have been described, the author has concentrated efforts on the phrenic nerve. This report describes the endoscopic laser medial arytenoidectomy procedure, while the phrenic nerve patients will be reported in a subsequent manuscript.

Respiratory Activity of the Rat Posterior Cricoarytenoid Muscle

1997 ◽  
Vol 106 (11) ◽  
pp. 897-901 ◽  
Author(s):  
Robert G. Berkowitz ◽  
John Chalmers ◽  
Qi-Jian Sun ◽  
Paul M. Pilowsky
Keyword(s):  
Phrenic Nerve ◽  
Muscle Activity ◽  
Electrophysiological Study ◽  
Emg Activity ◽  
Diaphragmatic Muscle ◽  
Posterior Cricoarytenoid Muscle ◽  
Inspiratory Activity ◽  
Intramuscular Nerve ◽  
Posterior Cricoarytenoid ◽  
Nerve Discharge

An anatomic and electrophysiological study of the rat posterior cricoarytenoid (PCA) muscle is described. The intramuscular nerve distribution of the PCA branch of the recurrent laryngeal nerve was demonstrated by a modified Sihler's stain. The nerve to the PCA was found to terminate in superior and inferior branches with a distribution that appeared to be confined to the PCA muscle. Electromyography (EMG) recordings of PCA muscle activity in anesthetized rats were obtained under stereotaxic control together with measurement of phrenic nerve discharge. A total of 151 recordings were made in 7 PCA muscles from 4 rats. Phasic inspiratory activity with a waveform similar to that of phrenic nerve discharge was found in 134 recordings, while a biphasic pattern with both inspiratory and post-inspiratory peaks was recorded from random sites within the PCA muscle on 17 occasions. The PCA EMG activity commenced 24.6 ± 2.2 milliseconds (p < .0001) before phrenic nerve discharge. The results are in accord with findings of earlier studies that show that PCA muscle activity commences prior to inspiratory airflow and diaphragmatic muscle activity. The data suggest that PCA and diaphragm motoneurons share common or similar medullary pre-motoneurons. The earlier onset of PCA muscle activity may indicate a role for medullary pre-inspiratory neurons in initiating PCA activity.

Laryngeal response to passively induced hypocapnia during NREM sleep in normal adult humans

1993 ◽  
Vol 75 (3) ◽  
pp. 1088-1096 ◽  
Author(s):  
S. T. Kuna ◽  
M. P. McCarthy ◽  
J. S. Smickley
Keyword(s):  
Vocal Cord ◽  
Spontaneous Breathing ◽  
Nrem Sleep ◽  
Normal Adult ◽  
Positive Pressure ◽  
Adductor Muscles ◽  
Posterior Cricoarytenoid Muscle ◽  
Adult Humans ◽  
Inspiratory Activity ◽  
Posterior Cricoarytenoid

Passively induced hypocapnia in animals activates vocal cord adductor muscles and decreases the glottic aperture. The purpose of this study was to determine if passively induced hypocapnia has similar effects in normal adult humans in stage 3/4 non-rapid-eye-movement (NREM) sleep. Hypocapnia was induced by hyperventilating the subjects with a positive-pressure ventilator via a nose mask. At hypocapnic levels below the CO2 apneic threshold, abrupt cessation of mechanical ventilation was followed by an apnea. In protocol 1, intramuscular electromyographic recordings of intrinsic laryngeal muscles were obtained in nine subjects. Activity of the posterior cricoarytenoid muscle, a vocal cord abductor, disappeared during passive hyperventilation. The muscle remained electrically silent during an apnea, but phasic inspiratory activity reappeared with the first respiratory effort. The thyroarytenoid and arytenoideus muscles, both vocal cord adductors, were electrically silent during spontaneous breathing in NREM sleep. Hypocapnia was frequently associated with activation of both adductor muscles. Once activated, the adductor muscles remained tonically active during an ensuring apnea. In protocol 2, a fiber-optic scope was advanced transnasally into the hypopharynx to determine glottic aperture size during passively induced hypocapnic apnea. In the seven subjects who achieved stable NREM sleep, the glottic aperture during an apnea was smaller than at any time throughout the respiratory cycle during spontaneous breathing just before positive-pressure ventilation. The results suggest that the decrease in glottic aperture observed during an induced hypocapnic apnea is due to suppression of the posterior cricoarytenoid muscle and/or activation of vocal cord adductor muscles.

Laryngeal Synkinesis: Its Significance to the Laryngologist

1989 ◽  
Vol 98 (2) ◽  
pp. 87-92 ◽  
Author(s):  
Roger L. Crumley
Keyword(s):  
Vocal Cord ◽  
Vocal Cord Paralysis ◽  
Basic Research ◽  
Laryngeal Electromyography ◽  
Bilateral Vocal Cord Paralysis ◽  
Laryngeal Function ◽  
Adductor Muscles ◽  
Posterior Cricoarytenoid Muscle ◽  
Posterior Cricoarytenoid ◽  
Intrinsic Laryngeal Muscles

Basic research and surgical cases have shown that the injured recurrent laryngeal nerve (RLN) may regenerate axons to the larynx that inappropriately innervate both vocal cord adductors and abductors. Innervation of vocal cord adductor muscles by those axons that depolarize during inspiration is particularly devastating to laryngeal function, since it produces medial vocal cord movement during inspiration. Many patients thought to have clinical bilateral vocal cord paralysis can be found to have synkinesis on at least one side. This will make the glottic airway smaller, particularly during inspiration, than would true paralysis of all the intrinsic laryngeal muscles. Patients with bilateral vocal cord paralysis should undergo laryngeal electromyography. If inspiratory innervation of the adductor muscles is present, simple reinnervation of the posterior cricoarytenoid muscle will fail. The adductor muscles also must be denervated by transection of the adductor division of the regenerated RLN.

Delayed Reinnervation of Unilateral Vocal Cord Paralysis in Dogs

1981 ◽  
Vol 89 (4) ◽  
pp. 608-612 ◽  
Author(s):  
G. David Neal ◽  
Charles W. Cummings ◽  
Dwight Sutton
Keyword(s):  
Vocal Cord ◽  
Vocal Cord Paralysis ◽  
Histologic Examination ◽  
Implantation Technique ◽  
Posterior Cricoarytenoid Muscle ◽  
Chronic Denervation ◽  
Posterior Cricoarytenoid ◽  
Unilateral Vocal Cord Paralysis

The neuromuscular implantation technique for rehabilitation of unilateral vocal cord paralysis was performed in four dogs at the time of denervation and in six dogs after varying intervals of chronic denervation. As would be expected, the chronically denervated animals did not achieve the vocal cord excursion of the acute denervations, but some return of motion was noted even after six months. Histologic examination of the posterior cricoarytenoid muscle was correlated with the return of movement.

Histochemical Study of Posterior Cricoarytenoid Muscle Reinnervation by a Nerve-Muscle Pedicle in the Cat

1987 ◽  
Vol 96 (5) ◽  
pp. 479-487 ◽  
Author(s):  
Joseph J. Fata ◽  
Leslie T. Malmgren ◽  
Richard Dum ◽  
Richard R. Gacek ◽  
Peak Woo
Keyword(s):  
Electrical Stimulation ◽  
Vocal Cord ◽  
Spontaneous Respiration ◽  
Glycogen Depletion ◽  
Quantitative Evidence ◽  
Airway Occlusion ◽  
Posterior Cricoarytenoid Muscle ◽  
Posterior Cricoarytenoid ◽  
Nerve Muscle ◽  
And Control

Reinnervation of the posterior cricoarytenoid (PCA) muscle with a nerve-muscle pedicle (NMP) has been proposed for patients with bilateral abductor vocal cord paralysis. Since its success has been controversial, a glycogen depletion histochemical technique was used to examine reinnervation. An ansa cervicalis NMP was implanted into the denervated PCA in nine cats. Eight months later, vocal cord activity was evaluated. The NMP nerve was stimulated extensively in seven cats (experimental group). Optical densities of NMP-supphed PCA muscle fibers from experimental and control groups were compared to detect differences in glycogen content. The results demonstrated quantitative evidence of reinnervation in two experimental animals. Electrical stimulation of the NMP produced abduction in one of these two animals, but was never observed during spontaneous respiration or airway occlusion. These observations indicate that reinnervation can occur but abduction requires electrical stimulation. The NMP technique may be more successful with an electrical pacer.

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