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 reaction, 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 mu g of type I collagen gel. Six animals were repaired with 300 mu g of type I collagen gel augmented with 3.0 mu g 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 a 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.