Abstract
The purpose of this investigation was to propose an experimental basis on which technical developments in phonosurgery can be expected. Canine larynges were used for the experiment. Six surgical procedures were applied along the length of unilateral vocal fold.
(1) Removal of the superficial layer of the lamina propria.
(2) Following the procedure 1, the wound was covered with an advanced mucosal flap.
(3) Removal of the entire mucosa.
(4) Following the procedure 3, the wound was covered with an advanced mucosal flap.
(5) Removal of the entire vocal fold.
(6) Following the procedure 5, the wound was covered with an advanced mucosal flap.
Phonatory function was investigated at earliest three months after the surgery in each canine. The function tests included measurements of subglottal pressure and mean air flow rate, observation of vibration of the vocal fold, and psychoacoustic evaluation of voice under different glottal adjustments.
The results were summarized as follows:
1. The greater the extent of removal was, the worse the phonatory function was.
2. Mucosal flap lessened disturbance of phonatory function in each experimented condition.
3. When removal of the superficial layer of the lamina propria was followed by mucosal flap procedure, almost normal function was obtained.
4. When removal of the entire mucosa was followed by mucosal flap procedure, the disturbance of function was thought to be compensated for by glottal adjustments.
5. When the entire vocal fold was removed, the recovery of phonatory function was impossible even by mucosal flap procedure. A necessity of reconstruction of a bulge comparable to the vocal fold was suggested for this condition.
