Surgical Method to Create Vocal Fold Injuries in Mice

Abstract

The goal of this study was to develop a surgical method for the creation of vocal fold injuries in mice, as a precursor to the use of genetically engineered mouse models in the study of vocal fold wound healing and scar formation. Seven FVB strain mice were used in this study. A laryngoscope and 3 micro-instruments were designed and fabricated to facilitate endoscopic vocal fold visualization and the creation of vocal fold surgical injuries. The larynges were harvested 1 and 7 days after surgery, and the vocal fold injury sites were evaluated by routine hematoxylin and eosin staining. Additional immunohistochemical analysis of collagen type I and elastin distribution in the lamina propria was performed for an uninjured control larynx. Endoscopic visualization and vocal fold stripping resulting in thyroarytenoid muscle exposure were successful in all animals. Histologic and immunohistochemical analyses revealed a simple lamina propria structure with relatively even collagen type I and elastin distribution in the control vocal fold, obliteration of vocal fold mucosa 1 day after surgery, and complete reepithelialization by 7 days. These results demonstrate the feasibility of creating reproducible vocal fold injuries via an endoscopic approach in mice. The observation that the mouse lamina propria may have a relatively simple histologic structure indicates that additional characterization should be performed and caution used in translating findings between this and other model systems.