高密度多孔聚乙烯兔眶壁植入后的血管纤维化进程

Fibrovascularization of high-density porous polyethylene implanted into the rabbit's orbit

目的探讨高密度多孔聚乙烯(high-density porous polyethylene,商品名Medpor)在兔眶壁植入后其血管纤维化进程和特点,为该材料临床应用的有效性与安全性提供理论指导。方法将相同厚度的Medpor修剪成相同大小块状植入兔眶壁,分不同时间点取出做组织学检查与电镜观察,对各时段不同切面、边缘和中央部分纤维化进程进行比较,并做相应统计学分析。所有标本取出后均从中部切开成两半,分别从断面和端面两个切面观察。结果高密度多孔聚乙烯植入11d后,所有标本完全纤维化,各个切面的纤维长入比率随时间推移呈递增趋势。端面边缘和中央纤维化进程差别有统计学意义,断面边缘和中央纤维化进程差别无统计学意义。4周后,各个切面毛细血管密度达到一致。电镜观察植入2周后,材料间隙纤维稀疏,4周后纤维致密。结论通道结构对相应部位的纤维血管化进程有一定的促进作用。高密度多孔聚乙烯植入4周后可以认为其度过临床危险期。

Objective To study the fibrovascularization of high- density porous polyethylene （Medpor） implanted into the rabbit＇s orbit to provide theoretical guidelines for the clinical application of the material. Methods The Medpor was cut to fit the superior or- hital floor and implanted into the orbital floor. The implanted Med- pors were removed at 2, 5, 8, 11, 14 and 28 days after implan- tation for histological study and removed 1, 2, 4, 6 and 8 weeks after implantation for observation under a scanning electron micro- scope. The density of the fibre and the ratio of fibrovaseularization in different sections and in different parts of sections were calculat- ed for statistical analysis. Each specimen was cut in the middle, and both surfaces of the transection and the butt end were evaluated. Results All specimens were completely fibrated at 11 days after implantation. The fibrovascularization rate gradually increased and there was a statistically significant difference between each interval. There was no statistical difference between the fibovaseular- ization of different parts of the transection, but a statistically sig- nificant difference was found between different parts of the butt end. There was no statistical significance of the fibovascularization difference between the transection and the butt end. Vascularization reached the same levels in the different parts of each section after 4 weeks. Under scanning electron microscopy, fibers were found to be sparse 2 weeks after implantation, while all the pores were full of compact fibres that bio-integrated with the implants after 4 weeks. Conclusion The channel-like structure in the material can accelerate fibovascularization. It can be assumed that the implant has the ability to resist infection and exposure 4 weeks after im- plantation.