This is a prospective, 2-part, multi-center, open-label, non-randomized clinical trial to assess safety and effectiveness of APrevent® VOIS Implants for the treatment of patients with Unilateral Vocal Fold Paralysis (UVFP). In total 30 evaluable patients are planned to be enrolled.

The APrevent® VOIS is intended to be permanently implanted during a type I thyroplasty in individuals suffering from permanent unilateral vocal fold paralysis of various etiologies. Four post-operative follow-up visits are planned: Week 1 (± 7 days), Week 7 (-7/+28 days), Month 6 (-14/+28 days) and Month 12 (-14/+28 days).

This 2-part study will consist of Part A to assess safety of the patients and the following Part B to assess the performance (effectiveness) of the investigational device. In Part A of the study 8 patients will be enrolled sequentially within three groups (N=1, N=2, N=5). After enrolment and 1st Follow-up Visit of each group, a Local Safety Board will review safety and study data. No preliminary/interim analysis of safety and effectiveness data will be performed before the end of the study.

Inclusion Criteria:

• Male and female patients between 18 and 80 years
• Diagnosed with permanent UVFP and insufficient glottal closure
• A significant voice disorder as measured by perceptual rating (Grade ≥2 GRBAS Scale) and Voice Handicap Index (VHI-30 score >33)
• Ability to comprehend the full nature and purpose of the study, including possible risks and side effects
• Ability to co-operate with the Investigator and to comply with the requirements of the entire study
• Availability to volunteer for the entire study duration, willing to adhere to all protocol requirements and willing and able to give informed consent for participation

Exclusion Criteria:

• Any other significant disease or disorder which, in the opinion of the investigator, may either put the participant at risk because of participation in the clinical investigation may influence the result of the clinical investigation, or the participant's ability to participate in the clinical investigation
• Scheduled elective surgery or other procedures requiring general anaesthesia during clinical investigation
• Bilateral vocal fold paralysis
• Had injection medialization laryngoplasty with the injectable still being within the double length of the maximum resorption time frame as stated in their approval or as supported by literature.
• Presence of structural vocal fold lesions such as polyp or nodules
• Presence of oropharyngeal or laryngeal tumors
• Patients with diagnosed severe obstructive sleep apnea (OSA)
• Status post total cordectomy
• Previous laryngeal framework surgery (any type of thyroplasty, arytenoid adduction)
• Status post tracheostomy
• Presence of acute systemic infection at time of screening or shortly before surgery
• Significant non-laryngeal speech abnormality (severe dysarthria determined by a panel of trained speech therapists)
• Severe coagulopathy
• Females who are pregnant, lactating or planning pregnancy are excluded from the investigation
• Patients with bil. Gr. III-IV hypertrophic tonsils
• Diabetes mellitus with poor control and poor wound healing history