Transcutaneous Laryngeal Ultrasound for Assessing Hyaluronic Acid Status in Patients Undergoing Injection Laryngoplasty.

ABSTRACT

OBJECTIVE: Injection laryngoplasty (IL) with hyaluronic acid (HA) is an effective treatment for patients with glottic insufficiency. The duration of HA maintenance in the vocal fold remains unknown. In this study, transcutaneous laryngeal ultrasound (TLUS) was used to evaluate the absorption and migration of HA after IL. Subsequent management might be provided based on the TLUS finding. METHODS: Patients diagnosed with unilateral vocal fold paralysis (UVFP) or vocal fold atrophy were recruited. All patients underwent IL with HA in an office-based setting along with TLUS to monitor the status of HA. The schedule of TLUS included assessments before and after IL until non-visualization. RESULTS: The study population comprised 38 women and 17 men. Of the patients, 54.1% underwent IL for UVFP, whereas 45.9% underwent IL for vocal fold atrophy. Multivariate Cox regression analysis for factors affecting HA absorption revealed that the cause of injection was the most important independent predictor (hazard ratio [HR], 2.15; 95% confidence interval [CI], 1.03-4.46; p = 0.040). The duration of HA maintenance was significantly longer in patients with UVFP than in those with vocal fold atrophy (8.77 vs. 4.70 months, HR, 2.33; 95% CI, 5.47-8.18; p = 0.002). CONCLUSION: TLUS is an objective assessment method for patients undergoing IL with HA. Subsequent tailor-made management could be offered based on the TLUS findings during follow-up. For patients at high risk of upper respiratory tract infection or who are intolerant to flexible nasopharyngoscopy, TLUS can be used as an alternative tool to evaluate the condition of the glottis after IL with HA. LEVEL OF EVIDENCE Level 4 Laryngoscope, 2024.