CVPath Institute, Inc., Gaithersburg, MD, USA.
EuroIntervention. 2019 Mar 20;14(16):1685-1693. doi: 10.4244/EIJ-D-17-00728.
Durable fluoropolymer-coated everolimus-eluting stents (FP-EES) have shown lower rates of stent thrombosis (ST) versus bare metal stents (BMS) and first-generation bioabsorbable polymer (BP) DES. The aim of the study was to evaluate the specific role of the FP in thromboresistance.
A total of 57 stents were assessed in three separate ex vivo swine arteriovenous shunt model experiments (first shunt experiment, custom-made fluoropolymer-coated BMS [FP-only] vs. BMS [n=8 each]; second shunt experiment, FP-EES vs. abluminally coated biodegradable polymer sirolimus-eluting stents [BP-SES] vs. BMS [n=8 each]; and third shunt experiment, FP-EES vs. polymer-free Biolimus A9-coated stents [PF-BCS] vs. BMS [n=6 each]). After one hour of circulation, stents were bisected, and each half was dual-immunostained using a platelet cocktail and a marker for inflammation. Antibody staining was visualised by confocal microscopy. In addition, stents were evaluated by scanning electron microscopy. FP-only stents showed significantly lower platelet adherence compared with BMS (% fluorescence-positive area: FP-only=1.8%, BMS=5.6%, p=0.047) with similar inflammatory cell density. FP-EES also demonstrated the lowest platelet adherence compared with BP-SES (p=0.056), PF-BCS (p=0.013) and BMS (p=0.003) with the significantly lowest inflammatory cell density.
Fluoropolymer coating imparts greater thromboresistance relative to BMS and to polymer-free DES designs, which reflects an unique phenomenon known as fluoropassivation, representing one proposed mechanism for clinically observed low ST rates in FP-EES.
与金属裸支架（BMS）和第一代生物可吸收聚合物（BP）DES 相比，耐用型含氟聚合物涂层依维莫司洗脱支架（FP-EES）显示出较低的支架血栓形成（ST）发生率。本研究旨在评估 FP 在抗血栓形成方面的特定作用。
在三个独立的体外猪动静脉分流模型实验中评估了 57 个支架（第一次分流实验，定制含氟聚合物涂层 BMS [FP-only]与 BMS [n=8 个]；第二次分流实验，FP-EES 与无涂层可生物降解聚合物西罗莫司洗脱支架 [BP-SES]与 BMS [n=8 个]；第三次分流实验，FP-EES 与无聚合物涂层 Biolimus A9 支架 [PF-BCS]与 BMS [n=6 个]）。循环 1 小时后，将支架切成两半，并用血小板鸡尾酒和炎症标志物对每一半进行双重免疫染色。通过共聚焦显微镜观察抗体染色。此外，还通过扫描电子显微镜评估支架。FP-only 支架的血小板黏附率明显低于 BMS（%荧光阳性面积：FP-only=1.8%，BMS=5.6%，p=0.047），而炎症细胞密度相似。FP-EES 与 BP-SES（p=0.056）、PF-BCS（p=0.013）和 BMS（p=0.003）相比，血小板黏附率最低，炎症细胞密度也最低，这表明氟聚合物涂层相对于 BMS 和无聚合物 DES 设计具有更强的抗血栓形成能力，这反映了一种称为氟钝化的独特现象，这是临床上观察到 FP-EES 低 ST 发生率的一种拟议机制。
