Safety and Efficacy of Injection Laryngoplasty- Hyaluronic Acid Versus Calcium Hydroxylapatite in Local and General Anesthesia Settings.

BACKGROUND

Injection laryngoplasty (IL) is a widely used and effective treatment for unilateral vocal fold paralysis (UVFP). However, the optimal choice of injectable material and anesthesia technique remains controversial. This study aimed to evaluate the safety and efficacy of IL and to compare voice outcomes between hyaluronic acid (HA) and calcium hydroxylapatite (CaHA), as well as between procedures performed under local (LA) and general anesthesia (GA).

METHODS

A total of 121 IL procedures were performed at a tertiary laryngology center in Malaysia between October 2014 and December 2023. Demographic data, anesthesia type, biomaterial, and complications were recorded. Patients were stratified by biomaterial and anesthesia type for outcome comparison. Multidimensional voice parameters, including the Bahasa Malaysia Voice Handicap Index-10 (mVHI-10), maximum phonation time (MPT), perceptual voice assessment, and acoustic analysis, were evaluated at baseline and 1 month post procedure. Pre- and post-procedure outcomes were analyzed using the Wilcoxon signed-rank test. The mean change of voice parameters at 1 month between groups was compared using the Mann-Whitney U test.

RESULTS

Iatrogenic injury was the most common cause of UVFP (60.3%). Statistically significant improvements (P < 0.05) were observed across all multidimensional voice parameters in both HA and CaHA groups, and in both LA and GA groups, at 1 month. No statistically significant differences in outcomes were found between HA and CaHA. However, the LA group demonstrated significantly greater improvements in most voice parameters compared with the GA group, except for MPT and perceptual breathiness. In multivariable linear regression analysis, baseline mVHI-10 score was the only independent improvement (P < 0.001), with higher baseline scores predicting greater improvement. Nine minor complications were reported (6.2% of injections).

CONCLUSIONS

IL is a safe and effective treatment for glottic insufficiency in patients with UVFP. Comparable short-term voice outcomes were observed between HA and CaHA. IL under LA may provide a better subjective voice outcome compared with the GA technique.