Evaluation of Surgical Strategies for Bilateral Vocal Fold Paralysis Using Excised Canine Larynges.

OBJECTIVE

The objective of this study was to provide a theoretical basis for the selection of optimal surgical procedures in ex vivo simulated bilateral vocal fold paralysis (BVFP).

STUDY

DESIGN

Four surgical stages were sequentially performed on 10 excised canine larynges with simulated BVFP: (1) transverse cordotomy, (2) medial arytenoidectomy, (3) subtotal arytenoidectomy, and (4) total arytenoidectomy.

MATERIALS AND

METHODS

The sound pressure level, the signal-to-noise ratio, the glottal resistance, the glottal airflow (GF), the maximal glottal area (MGA), and spectrograms were measured after each stage. For comparative analysis of variance, a randomized block design and the Student-Newman-Keuls test were performed.

RESULTS

Under stable phonation, the sound pressure level showed no significant differences among the four stages. The signal-to-noise ratio was significantly different between the preoperative period and stage 1, as well as between stages 2 and 3. Glottal resistance was significantly different between the preoperative period and stage 1 and between stages 1 and 2. GF and MGA were significantly different among all stages, compared with those between stages 3 and 4 for GF and the preoperative period and stage 1 for MGA. The spectrograms indicated that the degree of disorder in the acoustic signals gradually increased.

CONCLUSIONS

Based on a comprehensive analysis of GF and voice quality in excised canine larynges, which simulated BVFP, our results suggest that the optimal surgical choice for BVFP is either medial or subtotal arytenoidectomy.