1997 Fiscal Year Final Research Report Summary
PHONATORY MECHANISM OF ALARYNGEAL VOICE
| Project/Area Number |
07671855
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Otorhinolaryngology
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| Research Institution | Kobe University |
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Principal Investigator |
MOHRI Mitsuhiro KOBE UNIVERSITY SCHOOL OF MEDICINE DEPARTMENT OF OTORHINOLARYNGOLOGY HEAD & NECK SURGERY,INSTRUCTOR, 医学部・附属病院, 講師 (20166317)
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| Project Period (FY) |
1995 – 1997
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| Keywords | LARYNGEAL CANCER / TOTAL LARYNGECTOMY / TRACHEOESOPHAGEAL PHONATION / NEOGLOTTIS / THYROPHARYNGEAL MUSCLE / ELECTROMYOGRAPHY / ESOPHAGUS / EXPIRATION |
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| Research Abstract |
(1) Although tracheoesophageal (TE) speakers have lost the larynx, they produce voiceless and voiced sounds with articulatory adjustment. Fiberotic examination and electromyography (EMG)of the retropharyngeal prominence on which the neoglottis is located, revealed a transient neoglottal opening and decrease of EMG activity for voiceless sound production. This indicates that the neoglottic adjustment plays an important role to open the neoglottis in TE speech.
(2) The thyropharyngeal muscle which mainly consists of the neoglottis in TE speech is also reported to be activated by the expiratory act alone. Under equivalent tracheal pressure, there is clear difference in the muscle activity between the phonatory and the expiratory acts. Fluoroscopy and fiberscopy revealed a difference of the change in the volume of retropharyngeal prominence, which is characterized by the reduction of the craniocaudal length for phonation. EMG revealed lower activity of the muscle for phonation than that exp
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iratory act. These findings strongly suggests that TE speakers aquire a regulatory mechanism suitable for phoation by reducing contraction of the thyropharyngeal muscle.
(3) Two alarygeal voices, conventional esophageal voice and TE voice, have their own neoglottises. Manometry at the neoglottis performed in the subjects who could use both metods showed coincidence of the vibratory places in two voices. This indeicates that the neoglottises of TE and esophageal voices are located in the same position.
(4) The patient who employs TE phonation uses expiratory air passing through the TE fistula to vibrate the mucosa of the neoglottis located in the hypopharynx. Fiberscopy revealed a concentric closure of the esophagus through a ballooning of the subneoglottic lumen during phonation and its opening for the respiratory phase. Fluoroscopy revealed a dilated subneoglottic lumen with a closure of the esophagus at the bottom during phonation. These findings provide evidence for a mechanism to protect against the influx of the air deep into the esophagus during TE phonation. We conclude that, during phonation, a closed airway is established from the lung to the neoglottis, thatenables the TE speaker to use expiratory air most effectively for phonation.
(5) In 1983, a short procedure against aspiration was added to the original TE fistulization. It was arranged to obtain sphincter mechanism by looping the esophagus and TE fistula with muscle flaps obtained from the posterolateral aspect of the esophagus. The rate of aspiration during deglutition has been markedly decreased after this modification. Fluoroscopic examination was performed to TE speakers without aspiration to clarify the protective mechanism.The contrast medium in the fistula was trapped at the level of the muscle flaps, and esophageal dilation with slight elevation was seen at the upper level of the muscular loop. From these facts, the mechanism against aspiration was concluded to be the muscular loop constricting the fistula when esophagus dilates at swallowing. Less
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