Application of pitch range evaluation subsequent to arytenoid adduction and thyroplasty

The purpose of this study was to figure out the application of pitch range (PR) evaluation subsequent to arytenoid adduction (AA) combined with type 1 thyroplasty (TP1) in unilateral vocal fold paralysis (UVFP).

Retrospective review of clinical records.

Subjects were 50 patients with UVFP for whom PR and maximum phonation time (MPT) could be evaluated before and 1 year after AA + TP1. Subjects were divided into two groups based on preoperative PR (pre-PR) (group 1: ≤1 semitone (ST); group 2: ≥2 ST). Correlations among pre-PR and post-PR, MPT, and age were assessed. We also evaluated PRs in subjects with PR deterioration and PRs by causative diseases.

PR was significantly extended from a median of 17.0-22.0 ST in all subjects. Pre-PR was correlated with post-PR. Post-PR correlated with post-MPT in group 2 but not in group 1. There was no correlation between post-PR and age or causative diseases. The mean change in PR among subjects with PR deterioration (28.0%, 14/50) was -3.6 ST. Pre-PR and the improvement of post-PR were negatively correlated in group 2.

PR evaluation can be useful for predicting post-PR. The effects of age and causative diseases were small compared with other factors, such as pre-PR width and surgical effects. The successful surgery may improve both PR and MPT. However, several cases showed obvious discrepancy of those postoperative improvements. It will be necessary to assess this discrepancy, particularly in subjects with postoperative voice insufficiency.