title: Repair of nasal defects using collagen gels containing insulin-like growth factor 1.
abstract: 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).
  
  
  METHODS
  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 microg of type I collagen gel. Six animals were repaired with 300 microg of type I collagen gel augmented with 3.0 microg 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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, University of Virginia Health Sciences Center, Charlottesville, USA.
authors.forename: J S
authors.initials: JS
authors.lastname: Toung
authors.forename: A
authors.initials: A
authors.lastname: Griffin
authors.forename: R C
authors.initials: RC
authors.lastname: Ogle
authors.forename: W H
authors.initials: WH
authors.lastname: Lindsey
mesh_terms: D015502:Absorptiometry, Photon; D000818:Animals; D015519:Bone Density; D003094:Collagen / Q000008:administration & dosage / Q000627:therapeutic use*; D004195:Disease Models, Animal; D005500:Follow-Up Studies; D005782:Gels; D007334:Insulin-Like Growth Factor I / Q000008:administration & dosage / Q000627:therapeutic use*; D008297:Male; D009295:Nasal Bone / Q000473:pathology / Q000601:surgery*; D009667:Nose Deformities, Acquired / Q000473:pathology / Q000601:surgery*; D010012:Osteogenesis; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D014945:Wound Healing
chemical_list: D005782:Gels; D007334:Insulin-Like Growth Factor I; D003094:Collagen