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Physiologic effects of tracheostomy tube occlusion on the pharyngeal swallow
P 102
Otolaryngology Head and Neck Surgery August 1997
ResearchForum - - Monday
Poster 55
Neurological Assessment of Botulinum Toxin Effect ifl the Rat Larynx KATSUHIDE INAGI, MD (presenter), EDWARD SCHUL1-Z,PhD, CHARLES N, FORD, MD, ARTHUR A. RODRIQUEZ, MD, DIANE M. BLESS,PhD, and DENNIS HEISEY,PhD, Madison, Wis.
Increasing use of botulinum toxin (BT) in managing spasmodic dysphonia and related focal dystonias has provoked interest in assessing the neuromuscular recovery from BT injection. This study was designed to investigate the relationship between histological evidence of neuromuscular recovery and measured physiological functional recovery after BT injection in the rat larynx. With the use of botulinum toxin (0.01 Unit) with a v01ume of 0.2 microliters the thyroarytenoid muscle was injected. A custom-designed rat laryngoscope allowed videomicrolaryngoscopic assessment of vocal fold motion and peroral electromyographic recording. Physiologic function was assessed by using three parameters: (1) vocal fold motion, documented during quiet respiration with a video endoscope; (2) spontaneous electrical activity, recorded by electromyography with transorally placed electrodes; and (3) glycogen depletion assay following recurrent laryngeal nerve stimulation and sacrifice, quantified with digitized computer image analysis of those laryngeal muscle fibers staining positive for PAS. The numbers of both innervated and reinnervated subterminal axons were counted. The response to botulinum toxin injection in the rat larynx was documented within 6 hours. The maximum effect was observed 1 to 7 days after injection. During this period, fibrillation potentials developed. Some recovery of vocal fold movement and sprouting from subterminal axon were observed within 14 days after injection. Physiologic functional recovery to the preoperative status was achieved within 56 days after injections. Poster 56
A New Technique for Medialization of the Vocal Fold: Experimental Trial KATSUHIDE INAGI, MD (presenter), CHARLES N. FORD, MD, DIANE M. BLESS,PhD, and DENNIS HEISEY,PhD, Madison, Wis.
Arytenoid adduction, thyroplasty type I, and a combination of both procedures are commonly used for patients with glottal insufficiency. Arytenoid adduction adducts the vocal process of the arytenoid well and can reduce the glottal gap, but this technique results in little change of vocal fold tension. On the other hand, thyroplasty type I changes the vocal fold tension and can close a membranous glottal gap, but it is not often effective in closing the cartilaginous glottal gap. The combination of both techniques is the most effective method for the resolution of unilateral vocal fold paralysis in patients with a very large glottal gap. Unfortunately, this procedure takes a long time and can result in some damage to the larynx. The proposed technique can adjust the arytenoid position in three dimensions while simultaneously increasing tension of the vocal fold.
Excised human larynges were used to simulate unilateral vocal fold paralysis at the cadaveric fixation position. A fine needle with a 0.8 mm diameter and 3.5 mm length was inserted from 2 to 3 mm lateral to the anterior border of the thyroid cartilage at the level of the vocal fold. The needle was advanced through the interface between the thyroarytenoid muscle and the deep layer of the lamina propria to reach the body of arytenoid. The arytenoid position was then easily changed three-dimensionally by altering the direction of the needle. The best vocal function and most efficient vocal fold vibration obtained from medialization thyroplasty and our needle-positioning technique were compared. Poster 57
Physiologic Effects of Tracheostomy Tube Occlusion on the Pharyngeal Swallow ROXANN DIEZGROSS, MA (presenter), JEANNE E. MAHLMANN, PhD, and JUDITH P. GRAYHACK, PhD, Pittsburgh, Pa,
Introduction: Several studies have shown that restoration of subglottic air pressure by decannulation, capping, or the use of a Passy-Muir speaking valve reduces the incidence or severity of aspiration. The mechanism(s) by which restoration of a closed system alters pharyngeal swallowing function has not been systematically addressed. Objective: The purpose of this investigation was to compare bolus transit time, pharyngeal response time, and depth of laryngeal penetration during swallowing in subjects with open and occluded tracheostomy tubes. Methods: Four subjects, serving as their own controls, were studied fluoroscopically while swallowing thin liquid barium boluses under two conditions: open and occluded (using a Passy-Muir valve) tracheostomy tube. Timing measurements were made by frame counting. A penetration-aspiration scale was used to rate laryngeal penetration under the two conditions. Results: Bolus transit times and pharyngeal response times showed increased latency in the open condition when compared with the closed condition in all subjects (X = 61.9 msec and 161.8 msec, respectively). Three of the four subjects showed less penetration or depth of penetration in the closed condition. Conclusions: The results of this study suggest that subglottic air pressure may stimulate subglottic mechanoreceptots, which influence pharyngeal lower motor neuron recruitment. Poster 58
Laryngotracheal Reconstruction With Tracheal Patch Allografts 9 PIERRE DELAERE, MD, PhD (presenter), Leuven, Belgium
The capacity of tracheal allotransplants to provide optimal tissues for laryngotracheal repair was studied in an animal model. Segments of cervical trachea could be completely
Otolaryngology Head and Neck Surgery August 1997
ResearchForum - - Monday
Poster 55
Neurological Assessment of Botulinum Toxin Effect ifl the Rat Larynx KATSUHIDE INAGI, MD (presenter), EDWARD SCHUL1-Z,PhD, CHARLES N, FORD, MD, ARTHUR A. RODRIQUEZ, MD, DIANE M. BLESS,PhD, and DENNIS HEISEY,PhD, Madison, Wis.
Increasing use of botulinum toxin (BT) in managing spasmodic dysphonia and related focal dystonias has provoked interest in assessing the neuromuscular recovery from BT injection. This study was designed to investigate the relationship between histological evidence of neuromuscular recovery and measured physiological functional recovery after BT injection in the rat larynx. With the use of botulinum toxin (0.01 Unit) with a v01ume of 0.2 microliters the thyroarytenoid muscle was injected. A custom-designed rat laryngoscope allowed videomicrolaryngoscopic assessment of vocal fold motion and peroral electromyographic recording. Physiologic function was assessed by using three parameters: (1) vocal fold motion, documented during quiet respiration with a video endoscope; (2) spontaneous electrical activity, recorded by electromyography with transorally placed electrodes; and (3) glycogen depletion assay following recurrent laryngeal nerve stimulation and sacrifice, quantified with digitized computer image analysis of those laryngeal muscle fibers staining positive for PAS. The numbers of both innervated and reinnervated subterminal axons were counted. The response to botulinum toxin injection in the rat larynx was documented within 6 hours. The maximum effect was observed 1 to 7 days after injection. During this period, fibrillation potentials developed. Some recovery of vocal fold movement and sprouting from subterminal axon were observed within 14 days after injection. Physiologic functional recovery to the preoperative status was achieved within 56 days after injections. Poster 56
A New Technique for Medialization of the Vocal Fold: Experimental Trial KATSUHIDE INAGI, MD (presenter), CHARLES N. FORD, MD, DIANE M. BLESS,PhD, and DENNIS HEISEY,PhD, Madison, Wis.
Arytenoid adduction, thyroplasty type I, and a combination of both procedures are commonly used for patients with glottal insufficiency. Arytenoid adduction adducts the vocal process of the arytenoid well and can reduce the glottal gap, but this technique results in little change of vocal fold tension. On the other hand, thyroplasty type I changes the vocal fold tension and can close a membranous glottal gap, but it is not often effective in closing the cartilaginous glottal gap. The combination of both techniques is the most effective method for the resolution of unilateral vocal fold paralysis in patients with a very large glottal gap. Unfortunately, this procedure takes a long time and can result in some damage to the larynx. The proposed technique can adjust the arytenoid position in three dimensions while simultaneously increasing tension of the vocal fold.
Excised human larynges were used to simulate unilateral vocal fold paralysis at the cadaveric fixation position. A fine needle with a 0.8 mm diameter and 3.5 mm length was inserted from 2 to 3 mm lateral to the anterior border of the thyroid cartilage at the level of the vocal fold. The needle was advanced through the interface between the thyroarytenoid muscle and the deep layer of the lamina propria to reach the body of arytenoid. The arytenoid position was then easily changed three-dimensionally by altering the direction of the needle. The best vocal function and most efficient vocal fold vibration obtained from medialization thyroplasty and our needle-positioning technique were compared. Poster 57
Physiologic Effects of Tracheostomy Tube Occlusion on the Pharyngeal Swallow ROXANN DIEZGROSS, MA (presenter), JEANNE E. MAHLMANN, PhD, and JUDITH P. GRAYHACK, PhD, Pittsburgh, Pa,
Introduction: Several studies have shown that restoration of subglottic air pressure by decannulation, capping, or the use of a Passy-Muir speaking valve reduces the incidence or severity of aspiration. The mechanism(s) by which restoration of a closed system alters pharyngeal swallowing function has not been systematically addressed. Objective: The purpose of this investigation was to compare bolus transit time, pharyngeal response time, and depth of laryngeal penetration during swallowing in subjects with open and occluded tracheostomy tubes. Methods: Four subjects, serving as their own controls, were studied fluoroscopically while swallowing thin liquid barium boluses under two conditions: open and occluded (using a Passy-Muir valve) tracheostomy tube. Timing measurements were made by frame counting. A penetration-aspiration scale was used to rate laryngeal penetration under the two conditions. Results: Bolus transit times and pharyngeal response times showed increased latency in the open condition when compared with the closed condition in all subjects (X = 61.9 msec and 161.8 msec, respectively). Three of the four subjects showed less penetration or depth of penetration in the closed condition. Conclusions: The results of this study suggest that subglottic air pressure may stimulate subglottic mechanoreceptots, which influence pharyngeal lower motor neuron recruitment. Poster 58
Laryngotracheal Reconstruction With Tracheal Patch Allografts 9 PIERRE DELAERE, MD, PhD (presenter), Leuven, Belgium
The capacity of tracheal allotransplants to provide optimal tissues for laryngotracheal repair was studied in an animal model. Segments of cervical trachea could be completely