Single injection of basic fibroblast growth factor to treat severe vocal fold lesions and vocal fold paralysis

Abstract

Objectives/hypothesis: Severe vocal fold lesions such as vocal fold sulcus, scars, and atrophy induce a communication disorder due to severe hoarseness, but a treatment has not been established. Basic fibroblast growth factor (bFGF) therapies by either four-time repeated local injections or regenerative surgery for vocal fold scar and sulcus have previously been reported, and favorable outcomes have been observed. In this study, we modified bFGF therapy using a single of bFGF injection, which may potentially be used in office procedures.

Study design: Retrospective chart review.

Methods: Five cases of vocal fold sulcus, six cases of scars, seven cases of paralysis, and 17 cases of atrophy were treated by a local injection of bFGF. The injection regimen involved injecting 50 µg of bFGF dissolved in 0.5 mL saline only once into the superficial lamina propria using a 23-gauge injection needle. Two months to 3 months after the injection, phonological outcomes were evaluated.

Results: The maximum phonation time (MPT), mean airflow rate, pitch range, speech fundamental frequency, jitter, and voice handicap index improved significantly after the bFGF injection. Furthermore, improvement in the MPT was significantly greater in patients with (in increasing order) vocal fold atrophy, scar, and paralysis. The improvement in the MPT among all patients was significantly correlated with age; the MPT improved more greatly in younger patients.

Conclusions: Regenerative treatments by bFGF injection—even a single injection—effectively improve vocal function in vocal fold lesions.

Level of evidence: 4

Keywords: Basic fibroblast growth factor; local anesthesia; regenerative medicine; single injection; vocal fold lesion.

Figure 1

Fifty micrograms of basic fibroblastic growth factor (bFGF) dissolved in 0.5 mL saline are injected and spread into the superficial lamina propria (SLP). A 23‐gauge injection needle is used under transnasal fiberscopic monitoring of the larynx (A) before and (B) after the injection of the right vocal fold, and (C) before and (D) after the injection of the left vocal fold. The bFGF is injected into the SLP as if inflating a balloon.

Figure 2

Stroboscopic findings of a representative case. (A–L) show the stroboscopic findings at the first visit: on both sides, there is severe vocal fold atrophy that hardly vibrates. (M–X) After the injection of bFGF, the stroboscopic findings show an increase in the vocal fold membrane with improved vibration of the vocal folds.

Figure 3

The preinjective and postinjective values of (A) the maximum phonation time and (B) the mean airflow rate. All patients and subgroup analyses are presented. The open bar indicates the preinjective values, and the closed bar indicates the postinjective values. *P < .05. **P < .05.

Figure 4

The preinjective and postinjective values of (A) the pitch range and (B) the speech fundamental frequency. All patients and subgroup analyses are presented. The open bar indicates the preinjective values, and the closed bar indicates the postinjective values. *P < .05. **P < .05. ST = semitome.

Figure 5

The preinjective and postinjective values of (A) jitter and (B) the voice handicap index. All patients and subgroup analyses are presented. The open bar indicates the preinjective values, and the closed bar indicates the postinjective values. *P < .05. **P < .05.

Figure 6

Analysis of the correlation between the improvement after a single basic fibroblast growth factor injection and age. In all patients, the improvement in maximum phonation time is significantly correlated with age. The maximum phonation time (MPT) improved more in younger patients (P < .05).