Thromboembolism in blood vessels poses a serious risk of stroke, heart attack, and even sudden death if not properly managed. Sonothrombolysis combined with ultrasound contrast agents has emerged as a promising approach for the effective treatment of thromboembolism. Recent reports have highlighted the potential of intravascular sonothrombolysis as a safe and effective treatment modality for deep vein thrombosis (DVT). However, its efficiency has not been validated through in vivo testing of retracted clots. This study aimed to develop a miniaturized multidirectional transducer featuring two four-layer lead zirconate titanate (PZT-5A) stacks with an aperture size of 1.4 mm × 1.4 mm, enabling both forward- and side-looking treatment. Integrated into a custom two-lumen 10-French (Fr) catheter, the capability of this device for intravascular sonothrombolysis was validated both in vitro and in vivo. With low-dose tissue plasminogen activators and nanodroplets, the rotational multidirectional transducer reduced the retracted clot mass (800 mg) by an average of 52% within 30 min during in vitro testing. The lysis rate was significantly higher by 37% than that in a forward-viewing transducer without rotation. This improvement was particularly noteworthy in the treatment of retracted clots. Notably, a long-retracted clot (> 10 cm) was successfully treated within 40 min in vivo by creating a flow channel with a diameter > 4 mm in a porcine DVT model. In conclusion, these findings strongly suggest the potential of this technique for clinical applications in sonothrombolysis, offering a feasible solution for effectively treating thromboembolism, particularly in challenging cases involving retracted clots.

中文翻译：

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用于回缩凝块超声溶栓的旋转血管内多向超声导管：体外和体内研究


如果管理不当，血管血栓栓塞会带来中风、心脏病发作甚至猝死的严重风险。超声溶栓联合超声造影剂已成为有效治疗血栓栓塞的一种很有前途的方法。最近的报告强调了血管内超声溶栓作为深静脉血栓形成 （DVT） 安全有效的治疗方式的潜力。然而，其效率尚未通过回缩凝块的体内测试得到验证。本研究旨在开发一种小型化多向换能器，具有两个孔径尺寸为 1.4 mm × 1.4 mm 的四层锆钛酸铅 （PZT-5A） 堆栈，可实现前视和侧视治疗。集成到定制的双腔 10-French （Fr） 导管中，该设备的血管内超声溶栓能力在体外和体内均得到了验证。在体外测试期间，使用低剂量组织纤溶酶原激活剂和纳米液滴，旋转多向换能器在 30 分钟内将回缩的凝块质量 （800 mg） 平均减少了 52%。裂解率显著高于无旋转的前视换能器，高出 37%。这种改善在治疗回缩的凝块方面尤其值得注意。值得注意的是，通过在猪 DVT 模型中创建直径为 > 4 mm 的流道，在 40 分钟内在体内成功处理了长回缩的凝块 （> 10 cm）。总之，这些发现强烈表明该技术在超声溶栓临床应用方面的潜力，为有效治疗血栓栓塞提供了可行的解决方案，尤其是在涉及回缩凝块的具有挑战性病例中。