Age-dependent treatment effect of vocal fold steroid injection for benign vocal fold lesions.

Objective: Benign vocal fold lesions (BVFLs) cause voice disorders and impair social life. Recently, office-based vocal fold steroid injection (VFSI) has gained attention as a minimally invasive treatment for BVFLs. This study aimed to analyze the age-dependent treatment effect of VFSI and to clarify the indications for treatment. Methods: In this retrospective cohort study, a total of 83 patients with BVFLs were treated with a similar regimen of VFSI. Three or four months after the injection, age-dependent phonological functions were evaluated. The differences between pre- and post-treatment findings were analyzed using the Wilcoxon matched-pair signed-rank test, and the correlation between patient age and improvement rates were determined by Pearson's correlation coefficient. Results: Improvement in voice handicap index (VHI), which was the primary endpoint, was observed. Subjective and objective voice quality measurements also showed significant improvements. Subgroup analyses revealed that there was no age-related difference in the improvement of voice quality and that there was no improvement in aerodynamic effect in patients over 45 years of age. Conclusion: This study clarified the age-dependent treatment effect of VFSI and provided the important suggestion of establishing indication criteria for BVFLs. The study results provided clarity on the indication criteria of VFSI and served as an important indicator for tailoring treatment to patients' needs. Level of Evidence: 4.

Intracordal injection therapy for vocal fold scarring: Steroid versus basic fibroblast growth factor.

Objectives: Vocal fold scarring is caused by replacement of vocal fold mucosa with fibrous tissue due to repeated inflammation or trauma. It can lead to severe dysphonia. It is currently treated conservatively and with phonosurgery and intracordal injections. Intracordal injection of steroid or basic fibroblast growth factor (bFGF) has been recently found to be useful for treating vocal fold scarring that does not respond to voice therapy. Methods: This retrospective study involved the administration of steroid injection and bFGF injection bilaterally under local anesthesia in 16 patients each. Laboratory measurements of voice parameters were performed before and 3-6 months after injection. Results: In the steroid injection group, the Voice Handicap Index (VHI) score significantly improved from 57.1 to 40.5, total Grade, Roughness, Breathiness, Asthenia, Strain (tGRBAS) score significantly improved from 4.2 to 2.6, and mean speech fundamental frequency (SFF) increased from 192.5 to 211.4 dB, but there was no improvement in maximum phonation time (MPT) and mean airflow rate (MFR). In the bFGF injection group, significant improvements in the VHI score (from 53.3 to 35.7), MPT (from 16.9 to 21.8 s) and MFR (from 314.6 to 210.5 ml/s) were seen; however, the tGRBAS score did not improve. In addition, the SFF significantly decreased from 178.1 to 160.5 Hz. Conclusion: These results suggest that both steroid and bFGF injections are effective for treating vocal fold scarring, with steroids improving voice quality and bFGF improving glottic closure, thereby contributing to improvements in VHI scores. Level of Evidence: 4.