Comparative Histological Analysis of Collagen and Elastic Fibers Present in the Ventricular Folds and the Vocal Folds of Cadaveric Larynges

Introduction: Knowledge of the structural features of the vocal fold and the ventricular fold may help to understand the phonation process, and consequently may facilitate the use of the ventricular fold in phonation after laryngeal damage. Objective: To compare the histology and the distribution of collagen and elastic fibers between the ventricular folds and the vocal folds. Methods: Hemilaringes from 14 male cadavers were collected, processed for histology, sections stained for collagen and elastic fibers and analyzed. Results: The major part of the ventricular fold was lined with pseudostratified ciliated columnar epithelium containing goblet cells. In the ventricular folds the collagen fibers are homogeneously distributed in layers. In contrast, in the vocal fold the collagen fibers are unorganized and have a heterogeneous distribution. The percent of total collagen and of type I and type III collagen is similar between the vocal fold and the ventricular fold. However, the percent of type I collagen is increased in the ventricular fold in comparison to type III collagen. In the ventricular fold the elastic fibers are found in all layers of lamina propria, while in the vocal fold these elastic fibers are preferentially found in the deep layer of the lamina propria. The percent of elastic fibers is similar between the vocal folds and the ventricular folds. Conclusion: The percentage of collagen fibers and elastic fibers is similar between the vocal fold and the ventricular fold. However, in the ventricular fold the percentage of type I collagen is greater than type III collagen.