PURPOSE To evaluate the feasibility of utilizing a system of SMP acrylates for a thrombectomy device by determining an optimal crosslink density that provides both adequate recovery stress for blood clot removal and sufficient strain capacity to enable catheter delivery. METHODS Four thermoset acrylic copolymers containing benzylmethacrylate (BzMA) and bisphenol A ethoxylate diacrylate (Mn~512, BPA) were designed with differing thermomechanical properties. Finite element analysis (FEA) was performed to ensure that the materials were able to undergo the strains imposed by crimping, and fabricated devices were subjected to force-monitored crimping, constrained recovery, and bench-top thrombectomy. RESULTS Devices with 25 and 35 mole% BPA exhibited the highest recovery stress and the highest brittle response as they broke upon constrained recovery. On the contrary, the 15 mole % BPA devices endured all testing and their recovery stress (5 kPa) enabled successful bench-top thrombectomy in 2/3 times, compared to 0/3 for the devices with the lowest BPA content. CONCLUSION While the 15 mole% BPA devices provided the best trade-off between device integrity and performance, other SMP systems that offer recovery stresses above 5 kPa without increasing brittleness to the point of causing device failure would be more suitable for this application.

中文翻译：

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交联丙烯酸形状记忆聚合物在血栓切除术装置中的可行性。

目的通过确定最佳的交联密度来评估将SMP丙烯酸酯系统用于血栓切除术的可行性，该交联密度既可提供足够的恢复应力以去除血凝块，又可提供足够的应变能力以实现导管输送。方法设计了四种包含甲基丙烯酸苄酯（BzMA）和双酚A乙氧基化二丙烯酸酯（Mn〜512，BPA）的热固性丙烯酸共聚物，它们具有不同的热机械性能。进行了有限元分析（FEA）以确保材料能够承受压接所施加的应变，并对制成的设备进行力监控的压接，约束恢复和台式血栓切除术。结果BPA含量为25和35摩尔％的设备在受约束的恢复时断裂时表现出最高的恢复应力和最高的脆性响应。相反，15摩尔％的BPA设备经受了所有测试，其恢复应力（5 kPa）使台式血栓切除术成功完成了2/3倍，而BPA含量最低的设备为0/3。结论虽然15摩尔％BPA设备在设备完整性和性能之间提供了最佳折衷，但其他提供恢复应力在5 kPa以上而又不增加脆性到导致设备故障的点的SMP系统将更适合此应用。