Role of injectable collagen in the treatment of glottic insufficiency: a study of 119 patients.

Injectable bovine collagen has been used for treatment of glottic insufficiency at the University of Wisconsin Clinical Science Center since 1983. This report reviews our experience in treating 119 patients with a variety of vocal fold disorders manifested by glottic insufficiency. Many of the patients were referred because of prior treatment failures or problems that were impossible to treat with other modalities. Results were assessed by comprehensive voice evaluations using subjective patient self-assessments, perceptual judgments made by a panel of experts who had no prior knowledge of the study, objective assessments, and videostroboscopy. Objective assessment included vocal function measures and acoustic analysis. Results indicate that collagen not only is comparable to other injection filler substances but also has unique advantages as a bioimplant. Collagen injection seems uniquely suited for treatment of several problems, including vocal fold atrophy, focal defects, minimal glottic insufficiency, and scarred vocal folds that are not managed optimally with Teflon injection. Overall there were no serious complications and treatment was effective for a broad spectrum of problems. In most instances the correction persisted, and in those instances in which injected collagen seemed improperly distributed, the vocal fold was recontoured or the implant removed without appreciable damage to the surrounding tissues. Injectable collagen has been extensively studied and deserves to be included in the armamentarium of the laryngeal surgeon.