Kellar Robert S, Kleinert Leigh B, Williams Stuart K
Biomedical Engineering Program, University of Arizona, 1501 North Campbell Avenue, Tucson, Arizona 85724-5084, USA.
J Biomed Mater Res. 2002 Aug;61(2):226-33. doi: 10.1002/jbm.10021.
The response of epicardial tissue to the implantation of expanded polytetrafluoroethylene (ePTFE) was evaluated and compared with identical material implanted within subcutaneous and adipose tissues. These two tissue environments were selected for comparison with epicardial implants because they represent tissue often involved in device implantation. Discs of ePTFE (6 mm) were implanted into three different tissue sites in Sprague-Dawley rats. At 5 weeks, polymers and surrounding tissues were harvested and processed for light microscopy. General histology and histochemistry data indicated all polymers to be well incorporated with new tissue. Subcutaneous implants were covered by a dense fibrous capsule (55-70 microm). Epicardial and adipose implants had no fibrous capsule and a significantly greater number of microvessels (arterioles, capillaries, and venules) within the surrounding tissues compared with subcutaneous implants. An increased level of inflammation was also observed around epicardial implants compared with the other implants. Additionally, the new vasculature surrounding epicardially implanted ePTFE revealed an altered microvessel density and vessel type distribution compared with normal (control) epicardium. These results suggest that epicardial tissue responds to implanted ePTFE with a robust inflammatory response that may support the formation of a new microvasculature that is uniquely different from the native epicardial microvasculature.
评估了心外膜组织对膨体聚四氟乙烯（ePTFE）植入的反应，并与皮下和脂肪组织中植入的相同材料进行了比较。选择这两种组织环境与心外膜植入物进行比较，是因为它们代表了常参与装置植入的组织。将ePTFE圆盘（6毫米）植入Sprague-Dawley大鼠的三个不同组织部位。在5周时，收集聚合物和周围组织并进行光学显微镜检查。一般组织学和组织化学数据表明，所有聚合物都与新组织良好结合。皮下植入物被一层致密的纤维囊（55-70微米）覆盖。与皮下植入物相比，心外膜和脂肪植入物没有纤维囊，周围组织中的微血管（小动脉、毛细血管和小静脉）数量明显更多。与其他植入物相比，在心外膜植入物周围也观察到炎症水平升高。此外，与正常（对照）心外膜相比，心外膜植入的ePTFE周围的新生血管显示出微血管密度和血管类型分布的改变。这些结果表明，心外膜组织对植入的ePTFE产生强烈的炎症反应，这可能支持形成一种与天然心外膜微血管独特不同的新生微血管。
