Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, Massachusetts.
Winchester Engineering and Analytical Center, US Food and Drug Administration, Winchester, Massachusetts.
Catheter Cardiovasc Interv. 2019 Feb 1;93(2):278-285. doi: 10.1002/ccd.27726. Epub 2018 Sep 23.
Drug-eluting stent (DES) strut fracture (SF) is associated with higher incidence of In-stent restenosis (ISR)-return of blockage in a diseased artery post stenting-than seen with bare metal stents (BMS). We hypothesize that concomitance of drug and SF leads to greater neointimal response.
Controlled release of therapeutic agents, such as sirolimus and its analogs, or paclitaxel from has reduced tissue based DES failure modes compared to BMS. ISR is dramatically reduced and yet the implications of mechanical device failure is magnified.
Bilateral Xience Everolimus-eluting stents (EES) were implanted in 20 New Zealand White rabbits on normal (n = 7) or high fat (HF)/high cholesterol (HC) (n = 13) diets. Implanted stents were intact or mechanically fractured. Everolimus concentration was as packaged or pre-eluted. After 21 days, stented vessels were explanted, resin embedded, MicroCT scanned, and analyzed histomorphometrically.
Fractured EES were associated with significant (P < 0.05) increases in arterial stenosis and neointimal formation and lower lumen-to-artery area ratios compared to intact EES. Hyperlipidemic animals receiving pre-eluted EES revealed no significant difference between intact and fracture groups.
SF increases intimal hyperplasia, post EES implant, and worse with more advanced disease. Pre-eluted groups, reflective of BMS, did not show significant differences, suggesting a synergistic effect of everolimus and mechanical injury, potentially explaining the lack of SF reports for BMS. Here, we report that ISR has a higher incidence with SF in EES, the clinical implication is that patients with SF after DES implantation merit careful follow-up.
药物洗脱支架（DES）的支架断裂（SF）与支架内再狭窄（ISR）的发生率较高有关-支架置入后病变动脉再次阻塞-比裸金属支架（BMS）更常见。我们假设药物和 SF 的同时存在会导致更大的新生内膜反应。
与 BMS 相比，西罗莫司及其类似物或紫杉醇等治疗药物的控释可降低基于组织的 DES 失效模式。ISR 显著降低，但机械装置失效的影响却放大了。
在正常（n = 7）或高脂肪（HF）/高胆固醇（HC）（n = 13）饮食的 20 只新西兰白兔中植入双侧 Xience 依维莫司洗脱支架（EES）。植入的支架完整或机械断裂。依维莫司浓度为包装或预洗脱。21 天后，取出支架血管，树脂包埋，微 CT 扫描，进行组织形态计量学分析。
与完整的 EES 相比，断裂的 EES 与动脉狭窄和新生内膜形成的显著增加（P < 0.05）以及管腔与动脉面积比降低相关。接受预洗脱 EES 的高脂血症动物在完整和断裂组之间没有发现显著差异。
SF 增加了 EES 植入后的内膜增生，并且在疾病更严重时更严重。预洗脱组，反映了 BMS，没有显示出明显的差异，这表明依维莫司和机械损伤的协同作用，可能解释了 BMS 中 SF 报道缺乏的原因。在这里，我们报告说，EES 中的 SF 与 ISR 的发生率较高，临床意义是，DES 植入后发生 SF 的患者需要密切随访。
