Early Injection Laryngoplasty: Acoustic and Aerodynamic Outcomes with a Modified General Anesthesia Approach

Background and Objectives: This study aimed to evaluate postoperative changes in voice quality and glottic function following early injection laryngoplasty with hyaluronic acid performed using a modified general anesthesia approach without airway instrumentation in patients with unilateral vocal fold paralysis. Materials and Methods: Thirty-two patients (19 females, 13 males; mean age 51.8 years, range 21-70) who underwent injection laryngoplasty within the first three months after the onset of paralysis were included in this retrospective study. All procedures were performed under general anesthesia without endotracheal intubation, using endoscopic visualization. Objective acoustic and aerodynamic analyses and videostroboscopic examinations were performed preoperatively and postoperatively. Data were analyzed using the Wilcoxon signed-rank test, with p < 0.05 considered statistically significant. Results: Significant postoperative improvement was observed in acoustic and aerodynamic parameters. Shimmer, jitter, and noise-to-harmonic ratio (NHR) values significantly decreased (p < 0.001, p < 0.001, and p = 0.001, respectively), while maximum phonation time (MFT) increased markedly (p < 0.001) and the S/Z ratio decreased (p = 0.006). The mean fundamental frequency (F0) decreased slightly but not significantly (p = 0.085). Videostroboscopic findings demonstrated improved glottic closure and vocal fold vibration. No major complications occurred. Conclusions: Early injection laryngoplasty with hyaluronic acid performed under general anesthesia and endoscopic guidance provides significant improvement in objective voice parameters and glottic efficiency in unilateral vocal fold paralysis. Early intervention appears to enhance phonatory stability and may prevent maladaptive laryngeal changes.