Prospective >12 Months Outcomes After Vocal Fold Injection Medialization With Silk Microparticle-Hyaluronic Acid Material.

OBJECTIVE: Vocal fold injection medialization (VFIM) is widely used as an initial treatment for unilateral vocal fold paralysis (UVFP). Current practices employ materials that share the limitation of temporary clinical effect from variable resorption rates. A novel silk protein microparticle-hyaluronic acid-based material (silk-HA) has demonstrated cellular infiltration and tissue deposition that may portend a durable medialization effect. We report on ≥12 months outcomes after VFIM with silk-HA.

METHODS: Prospective open-label study of patients with UVFP that elected treatment with VFIM with silk-HA. Blinded experts rated laryngeal stroboscopic exams.

RESULTS: Seventeen patients with UVFP underwent VFIM with silk-HA. Twelve of the 17 patients have ≥12 months follow-up. Seven patients demonstrated durable treatment benefit ≥12 months after injection with median improvement of 19 (p = 0.0156) in VHI-10. There was no significant change in VHI-10 between 1 and 12 months for these patients. Blinded ratings indicated that 5/7 patients with sustained improvements in VHI-10 exhibited complete or touch glottal closure at 12 months. Two of the seven patients exhibited a small (<1 mm) glottal gap at 12 months. Seven patients experienced initial benefit with later regression 3-4 months after injection.

CONCLUSION: VFIM with silk-HA can offer durable improvement in voice-related outcomes for UVFP past 12 months. A subset of patients treated with silk-HA experienced early loss of effect around 3-4 months postinjection. Clinical factors predictive of sustained treatment response to silk-HA injection require further exploration.

LEVEL OF EVIDENCE: 3 Laryngoscope, 2023.