Voice recovery in eight Yucatan mini-pigs after vocal fold implantation surgery

As there currently exists no standardized framework to assess pig voice health, and voice parameters designed for humans do often not work on aperiodic pig voice, new approaches must be developed. We performed cell-based outer vocal fold replacement (COVR) surgery in six Yucatan mini-pigs (with two pigs in the control group) and tracked functional and structural voice recovery over up to six months. Recovery of voice function was assessed by tracking acoustic parameters and spectrograms in three pigs. Structural recovery was assessed by histologic analysis and Amino Acid Quantitation after harvest of vocal fold tissue in three pigs each. The results of functional analysis reflect expected voice worsening right after surgery and gradual recovery in one pig that was tracked the longest. Structural analysis shows small differences in fiber directionality between control group and pigs after surgery. Increasing amounts of detected amino acid markers for collagen and elastin over time after surgery may hint on gradual structural recovery. With this preliminary work, we form the basis for a larger long-term pre-clinical safety and efficacy study of COVR implantation.