Comparative Results of Vocal Fold Injury According to the Fiber-Based Laser in a Rabbit Vocal Fold Model

Gyeong Hwa Jeon; Sang Woo Seon; Seung Won Lee

doi:10.1016/j.jvoice.2023.01.029

Comparative Results of Vocal Fold Injury According to the Fiber-Based Laser in a Rabbit Vocal Fold Model

J Voice. 2023 Feb 25:S0892-1997(23)00029-2. doi: 10.1016/j.jvoice.2023.01.029. Online ahead of print.

Authors

Gyeong Hwa Jeon¹, Sang Woo Seon², Seung Won Lee³

Affiliations

¹ Department of Otolaryngology-Head and Neck Surgery, Soonchunhyang University Seoul Hospital, Soonchunhyang University College of Medicine, Seoul, Republic of Korea.
² Department of Otolaryngology-Head and Neck Surgery, Soonchunhyang University Bucheon Hospital, Soonchunhyang University College of Medicine, Bucheon, Republic of Korea.
³ Department of Otolaryngology-Head and Neck Surgery, Soonchunhyang University Bucheon Hospital, Soonchunhyang University College of Medicine, Bucheon, Republic of Korea. Electronic address: lsw0922@schmc.ac.kr.

PMID: 36849301
DOI: 10.1016/j.jvoice.2023.01.029

Abstract

Objectives: We assessed the safety of flexible fiber-based lasers including the potassium-titanyl-phosphate (KTP), CO₂, and Holmium lasers using a rabbit vocal fold model and provided the safety evidence of laser before human clinical trial.

Methods: In all, 120 male New Zealand white rabbits were used. Each laser was used to induce acute and chronic vocal fold injuries in 40 rabbits. The same laser energy with the same intensity and frequency were used in all cases, and we evaluated outcomes via surface scanning electron microscopy (SEM) and histological examination 1 day after injury. Histological and high-speed vocal fold vibration examinations were evaluated 1 month after injury. Surface injury roughness grading was done via SEM, and the Acute injury ratio and lamina propria (LP) ratio were also calculated. The dynamic glottal gap was measured through functional analyses based on recordings from a high-speed digital camera.

Results: The Holmium laser caused significantly more vocal fold damage than did the KTP and CO₂ lasers as revealed by SEM and evaluation of acute and chronic injuries. Functional analysis with high-speed digital camera indicated that the holmium laser reduced dynamic glottal gap compared with the normal vocal fold, where the other lasers did not.

Conclusions: The histological and functional analyses of rabbit vocal fold experiments indicated that fiber-based laryngeal laser surgery for vocal fold lesions could be performed relatively safely using a KTP or CO₂ laser.

Keywords: Animal model; Fiber-based; Laser; Vocal fold.