Repair of nasal defects using collagen gels containing insulin-like growth factor 1^†

Objective: Facial osseous defects are a common and challenging problem for the otolaryngologist—head and neck surgeon. Current methods of repair including synthetic grafts, cadaveric material, and autologous tissue have drawbacks of foreign body reactions, infectious agent transmission, and the morbidity of a second surgical site. In the effort to develop an ideal technique for osseous reconstruction, a critical-size facial defect has previously been developed in the Sprague-Dawley rat. This model exhibits less than 10% healing by surface area over 6 months. A novel approach to osseous reconstruction is attempted using this model with type I collagen gel augmented with insulin-like growth factor 1 (IGF-1). Study Design: Randomized controlled trial using a rodent model. Methods: Twelve adult male Sprague-Dawley rats underwent a surgical procedure to produce a critical-size nasal defect by removing the nasal bones with a cutting burr. Six animals were repaired with 300 μg of type I collagen gel. Six animals were repaired with 300 μg of type I collagen gel augmented with 3.0 μg of IGF-1. Thirty days later, the animals were examined after necropsy. Precise planimetry, radiodensitometric analysis, and histologic sectioning were performed. Results: All animals had complete coverage of this defect with a thin layer of bone. Radiodensitometric analysis indicated that there was a statistically significant (P < .037) increase in bone density in the collagen plus IGF-1 group compared with that of collagen only. In addition, histologic evaluation revealed increased bone density and thickness in the IGF-1 group. Conclusion: Type I collagen gel augmented with IGF-1 results in a significant increase in healing of a nasal critical-size defect in a rodent model. Laryngoscope, 108:1654–1658, 1998