A preliminary study of injectable collagen in human vocal fold augmentation.

Soluble bovine collagen was injected for vocal fold augmentation in 27 patients with glottic insufficiency. Preliminary observations show that glottic closure was enhanced in all patients with no serious complications. Subjective and objective measures of vocal efficiency indicated improvement with reduction in airflow, improved glottic closure, and increased vocal intensity. Recent studies that reveal distant migration of injected Teflon suggest the need for the development of a safe biologic material for soft tissue augmentation. Collagen appears to satisfy criteria as an ideal bioimplant, tends to soften scar tissue, and is structurally similar to natural collagen in the human vocal fold. Further longitudinal studies and the development of potentially more stable cross-linked collagen preparations seem indicated.