An Experimental Study On Angiogenesis Of Non-vascularized Autogenous Bone Graft With Vascular Bundle Implantation

Objective: Bone transplantation is a convenient and efficient method of bone defect reconstruction. Autogenous bone is transplanted from another part of the patient's own body. Autogenous bone grafts have currently been the material of choice in reconstructive surgeries because of advantages such as mechanical stability and lack of immunogenicity. Bone healing relies on revascularization of bone graft. This study was to accelerate angiogenesis in autogenous bone graft by vascular bundle implantation.Methods: Thirty-six New Zealand White rabbits were evaluated in this study. A portion of a rabbit bilateral radio bones were removed as free bone grafts, whose periostea were peeled off. In test group, the external maxillary artery bundle was passed through the marrow cavity of the bone. In control group, there were no vascular bundle implantation. Each bone was placed in the masseter muscle separately. The rabbits were sacrificed and the specimens were procured at 3 days, 1, 2, 3, 4 and 6 weeks after surgery for histological observation, Chinese ink perfusion, tetracycline fluorescence labeling and CD34 immunohistochemistry. Microvessel density(MVD) and tetracycline fluorescence labeling intergrated optical density(IOD) were assessed in order to evaluate angiogenesis and rate of new bone formation of autogenous bone grafts.Results: The bone grafts were found revasculatized at 3 days after surgery in the test group, whereas at 2 weeks in the control group. At 3 days, 1 week, 2 weeks, 3 weeks and 4 weeks after surgery, the MVD of test group was significantly higher than that of control group. At 4 weeks after surgery, angiogenesis of test group reached a peak. At 2 weeks, 3 weeks, 4 weeks and 6 weeks after surgery, the tetracycline fluorescence labeling intergrated optical density(IOD) of test group was significantly higher than that of control group.Conclusions: Vascular bundle implantation improved angiogenesis in non-vascularized autogenous bone graft in this study. Improved angiogenesis accelerated new bone formation, thereby availing to bone healing.