Purpose: Persistent unilateral vocal fold paralysis (UFVP) with glottal insufficiency often requires type I medialization thyroplasty (MT). Previous implants cannot be adjusted postoperatively if necessary. The newly developed APrevent® VOIS implant (VOIS) can provide postoperative re-adjustment to avoid revision MT. The objective of this pilot study is to evaluate the VOIS intraoperatively concerning voice improvement, surgical feasibility and device handling.
Methods: During routine MT, VOIS was applied short time in eight patients before the regular implantation of the Titanium Vocal Fold Medialization Implant (TVFMI™). In all patients, perceptual voice sound analysis using R(oughness)-B(reathiness)-H(oarseness)-scale, measurement of M(aximum)-P(honation)-T(ime) and glottal closure in videolaryngoscopy were performed before and after implanting VOIS/TVFMI™. Acoustic analyses of voice recordings were performed using freeware praat. Surgical feasibility, operative handling and device fitting of VOIS and TVFMI™ were assessed by the surgeon using V(isual)-A(nalog)-S(cale). Data were statistically analyzed with paired t test.
Result: All patients showed significant improvement of voice sound parameters after VOIS/TVFMI™ implantation. The mean RBH-scale improved from preoperative R = 2.1, B = 2.3, H = 2.5 to R = 0.6, B = 0.3, H = 0.8 after VOIS and R = 0.5, B = 0.3, H = 0.8 after TVFMI™ implantation. The mean MPT increased from preoperative 7.9 to 14.6 s after VOIS and 13.8 s after TVFMI™ implantation. VOIS/TVFMI™ achieved complete glottal closure in 7/8 patients. The satisfaction with intraoperative device fitting and device handling of VOIS was as good as that of TVFMI™.
Conclusion: The novel APrevent® VOIS implant showed similar intraoperative voice improvement compared to routinely used TVFMI™ without adverse device events and with safe device fitting.
Keywords: Laryngology; Medialization thyroplasty; TVFMI; UVFP; VOIS; Vocal fold paresis/paralysis.