血管性假血友病因子预测静脉留置针致兔耳缘静脉血栓形成的研究

Research on vWF Predicting Thrombosis in Rabit Ear Vein Caused by Introvenous Catheters

目的观察静脉留置针致兔耳缘静脉血栓形成、局部血管内皮损伤以及血浆血管性假血友病因子(von Willebrand factor,vWF)表达情况,分析vWF改变与血栓形成的相关性。方法60只大耳白兔随机分成3、5、7d三组,取右耳外侧耳缘静脉置20号留置针,每日经留置针输入生理盐水20ml模拟临床输液,检测置针前后血浆vWF水平变化,并各组分别于第3、5、7d取置针侧耳缘静脉做病理切片,光镜下观察血管内血栓形成,透射电镜观察血管内皮超微结构变化。结果3、5、7d组血栓形成率分别为45%、78.9%、89.5%。3d组血管内皮层完整,线粒体、内质网无明显变化;5d组血管内皮层基本完整,局部内皮细胞增生,线粒体、内质网水肿;7d组血管内皮层多破坏缺失,暴露内皮下基质,严重者血管被破坏,结构不清,可见大量脱落坏死细胞。3d组、5d组vWF水平与血栓形成情况呈正相关,7d组内vWF水平与血栓形成情况呈负相关。结论血管内皮损伤为静脉留置针血栓形成机制之一,vWF可以作为预测静脉留置针血栓发生风险指标。

Objective To observe vascular endothelial cell injuries, expression of plasm VWF（ yon Wiilebrand factor） and thrombogenesis of rabbit ear vein caused by intravenous catheter and to analyze the correlation between VWF fluctuation and thrombogenesis. Methods Divide 60 Giant Ear Rabbits into 3 groups： 3- day group, 5-day group and 7-day group respectively. Put type-20 intravenous catheter in right ear vein of each rabbit, then infuse 20 ml normal saline every day through the catheter to simulate clinical transfusion. Next, detect level of plasm VWF before and after the placement. Then, pathological sections of ear vein where the intra- venous catheter was detained are made on the 3ird, 5th and 7th day. Observe intravenous thrombogenesis through microscope and ultramicrostructure of endothelial ceils through transmission electron microscope. Results Incidences of thrombus in three groups are 45%, 78.9% and 89.5% respectively. Vascular endothelial layers of 3- day group are integrated, there is no significant change of mitochondria and endocytoplasmic reticulum. Cells of endothelial layer in 5-day group aren＇ t lost on the whole, part of which is in proliferation. Edema appeared in mitochondria and endocytoplasmic reticulum. However, most of endothelial layers in 7day group are destroyed and lost, exposing the matrix under endothelium. Some vessels were destroyed, the vascular construction cant＇ t be sistinguished. Lots of exfoliated and necrotic cells can be found. A positive correlation exists between VWF and thrombogenesis in 3-day group and 5-day group. However, it reveals a negative correlation in 7-day group. Conclusion Endothelial cell injuries may be one of mechanisms of thrombogenesis caused by intravenous catheter. VWF could be the risk-index to detect the thrombogenesis caused by intravenous catheter.