The effect of polyethylene orbital implant(Medpor(R)) pretreated with autogenous fibrovascular tissues in rabbits

ABSTRACT

PURPOSE: The purpose of this study is to determine whether partially neovascularized Medpor(R) by preplacement of implant to buttock area for one month before secondary orbital insertion demonstrates earlier refibrovascular ingrowth into implant than that in primary orbital placement. METHODS: Thirty-five rabbits were divided into two groups Group A (15 rabbits) ; primary orbital implantation of Medpor(R)(nonvascularized) after enucleation, Group B (15 rabbits) ; secondary orbital implantation of implant (vascularized) after enucleation after harvesting implants from buttock area, inserted for one month prior to orbital implantation. Five neovascularized implants by preplacement of implant to buttock area for one month were sectioned and investigated for the fibrovascular ingrowth, expression of bFGF, and CD-31 to evaluate the influence of pretreatment. Implants from group A and B were harvested from the orbit at 1, 2, 4, 6, and 8 weeks postoperatively. The implants were sectioned and studied grossly and histopathologically. Immunohistochemical study on bFGF and CD-31 were conducted to detect the angiogenetic factor and degree of angiogenesis in both group A and B. RESULTS: The fibrovascular ingrowth and expression of bFGF and degree of angiogenesis in group B were higher than those in group A. The degrees of angiogenesis were well correlated with bFGF expression. CONCLUSIONS: This animal model may provide the basis for the future investigation of agents and structural modifications directed towards optimization of fibrovascular ingrowth into porous anophthalmic socket implants and clinically apply to enucleation for the vascular compromised patients such as in the settings of postirradiation, diabetes.