Pre-clinical evaluation of APrevent® VOIS for unilateral vocal fold paralysis medialization

Guan-Min Ho; Jasmin Rast; Li-Chun Hsieh; Arne Böttcher; Stefan Meng; Lukas F Reissig; Chieh-Han Tzou; Markus Maria Hess; Berit Schneider-Stickler; Jack Jiang; Yin-Ta Lai; Sheng-Po Yuan; Ying-Piao Wang; Stefan H Geyer; Wolfgang J Weninger

doi:10.1002/lio2.1059

Pre-clinical evaluation of APrevent® VOIS for unilateral vocal fold paralysis medialization

Laryngoscope Investig Otolaryngol. 2023 Apr 21;8(3):712-719. doi: 10.1002/lio2.1059. eCollection 2023 Jun.

Authors

Guan-Min Ho^{1

2

3}, Jasmin Rast^{4

5}, Li-Chun Hsieh¹, Arne Böttcher⁶, Stefan Meng^{7

8}, Lukas F Reissig⁸, Chieh-Han Tzou^{4

9

10}, Markus Maria Hess¹¹, Berit Schneider-Stickler¹², Jack Jiang¹³, Yin-Ta Lai¹⁴, Sheng-Po Yuan^{14

15}, Ying-Piao Wang¹, Stefan H Geyer⁸, Wolfgang J Weninger⁸

Affiliations

¹ Department of Otolaryngology-Head and Neck Surgery Mackay Memorial Hospital Taipei Taiwan.
² Yomin ENT and Pediatric Clinic Taipei Taiwan.
³ APrevent Medical Taipei Taiwan.
⁴ Plastic and Reconstructive Surgery, Department of Surgery Hospital of Divine Savior Vienna Austria.
⁵ Department of Plastic and Reconstructive Surgery St. Josef Hospital Vienna Austria.
⁶ Otolaryngology-Head and Neck Surgery University Medical Center Hamburg-Eppendorf (UKE) Hamburg Germany.
⁷ Department of Radiology Hanusch Hospital Vienna Austria.
⁸ Division of Anatomy, MIC, CMI Medical University of Vienna.
⁹ Medical Faculty Sigmund Freud University Vienna Austria.
¹⁰ TZOU Medical Vienna Austria.
¹¹ Medical Voice Center (MEVOC) Hamburg Germany.
¹² Department of Otorhinolaryngology Medical University of Vienna Vienna Austria.
¹³ Department of Surgery, Division of Otolaryngology-Head and Neck Surgery University of Wisconsin School of Medicine and Public Health Madison Wisconsin USA.
¹⁴ Department of Otolaryngology, Shuang Ho Hospital Taipei Medical University Taipei Taiwan.
¹⁵ Graduate Institute of Biomedical Informatics, College of Medical Science and Technology Taipei Medical University Taipei Taiwan.

Abstract

Objective: To evaluate the concept and efficacy of an adjustable implant (Prototype SH30: porcine implant and APrevent® VOIS: human concept) for treatment of unilateral vocal fold paralysis (UVFP) via in vivo mini-pig studies, human computed tomographic (CT) and magnetic resonance (MR) image analysis, ex-vivo aerodynamic and acoustic analysis.

Methods: Feasibility testing and prototype implantation were performed using in-vivo UVFP porcine model (n = 8), followed by a dimensional finding study using CT and MR scans of larynges (n = 75) for modification of the implant prototypes. Acoustic and aerodynamic measurements were recorded on excised canine (n = 7) larynges with simulated UVFP before and after medialization with VOIS-Implant.

Results: The prototype showed in the in-vivo UVFP porcine model an improved glottic closure from grade 6 incomplete closure to complete closure (n = 5), to grade 2 incomplete closure (n = 2) and grade 3 incomplete closure (n = 1). On human CT/MR scans the identification of the correct size was successful in 97.3% using the thyroid cartilage alar "distance S" as the only parameter, which is an important step towards procedure standardization and implant design. Results were confirmed with implantation in human laryngeal cadavers (n = 44). Measurements of the acoustic and aerodynamic effects after implantation showed a significant decreased phonation threshold pressure (p = .0187), phonation threshold flow (p = .0001) and phonation threshold power (p = .0046) on excised canine larynges with simulated UVFP. Percent jitter and percent shimmer decreased (p = .2976; p = .1771) but not significant.

Conclusions: Based on the preclinical results four sizes, differing in medial length, implant width and expansion direction of silicone cushions, seem to be enough to satisfy laryngeal size variations. This concept is significantly effective in medializing UVFP and improving the aerodynamic and acoustic qualities of phonation as reported in a preliminary clinical outcome study with long-term implantation.

Level of evidence: N/A.

Keywords: UVFP; VOIS; adjustable implant; type I (medialization) thyroplasty; vocal fold paralysis.