Preliminary Results on the Safety and Efficacy of Silk-Hyaluronic Acid for Treatment of Glottic Insufficiency.

Objectives: Silk-Hyaluronic Acid (Silk-HA) is a novel vocal fold augmentation material that has been used in humans since July 2020. There is a paucity of published data on Silk-HA and its longevity remains a question. This study aimed to evaluate a single surgeon's initial experience performing Silk-HA injection laryngoplasty for the treatment of glottic insufficiency.

Methods: Retrospective chart review of Silk-HA injections between July 2020 and December 2021. Subject demographics, diagnoses, volume of material injected, VHI-10 data, and complications were collected. A blinded perceptual voice analysis of voice samples was performed by two voice-specialized speech-language pathologists (SLP) for a subset of unilateral vocal fold paralysis patients before and 3-months following silk-HA injection. Univariate assessment of the change in VHI-10 and perceptual voice analyses at 3-month follow up was determined.

Results: 58 patients (43.1% female) underwent Silk-HA injection with a mean age of 64 (range 21-88). 38 subjects had unilateral paralysis (65.6%), and the remaining had scar, atrophy, paresis or a combination thereof. 49 injections were unilateral (84.5%). Mean volume of silk injected was 0.26 mL. Complications were rare, most notable though for 2 admissions for dyspnea and laryngoscopic evidence of hemi-laryngeal edema (3.4%). Mean change in CAPE-V overall severity rating was -32.9 (P<0.0001), and VHI-10 was -14.6 ± 10 (P=0.0013). 14 patients underwent a repeat silk-HA injection for ongoing glottic insufficiency (loss of augmentation vs under-augmentation).

Conclusions: Preliminary results for Silk-HA show potential for ongoing improvement of glottic insufficiency at 3 months from date of augmentation. Clinician and patient perception of voice outcomes showed overall improvement at three months, though longevity remains to be determined. While overall well tolerated and without serious complications in 96% of the cohort, patients should be counseled on the potential for airway edema and symptomatic dyspnea requiring steroid management and observation.