Histologic Evaluation of Intracordal Autologous Cartilage Injection in the Paralyzed Canine Vocal Fold at Two and Three Years

Abstract

OBJECTIVE: Intracordal injection for vocal fold augmentation is easy and simple and does not require a cervical skin incision. We reported previously on the 1-year results of injected autologous auricular cartilage for volumetric augmentation in paralyzed canine vocal cord. This study evaluates the long-term histomorphologic results of injected autologous auricular cartilage for the augmentation of the paralyzed canine vocal fold at 2 and 3 years. STUDY DESIGN AND SETTING: A prospective trial of autologous cartilage augmentation of vocal cord in animal model. Five dogs were operated on. A piece of auricular cartilage was harvested from the ear and minced into tiny chips with a scalpel. Fat was harvested from inguinal area and minced with a scalpel. The minced cartilage and fat-paste (0.2 ml) was injected using a pressure syringe into the paralyzed thyroarytenoid muscle using direct laryngoscopy. Three animals were sacrificed at 2 years, two at 3 years. Each subject underwent laryngectomy and serial coronal sections of paraffin blocks from the posterior vocal fold were made. RESULTS: There was no significant complications perioperatively or postoperatively. The injected cartilage that seemed to have lost viability existed in the vocalis muscles until 36 months. Fibrotic change was exhibited in the surrounding injected cartilage. There were no differences between 2 and 3 years in histomorphologic results of the injected cartilage. CONCLUSION: The autologous auricular cartilage graft is well tolerated and may be a very effective material for long-term volumetric augmentation in the paralyzed vocal cord.