In vitro and in vivo high-intensity focused ultrasound thrombolysis.
In vitro and in vivo high-intensity focused ultrasound thrombolysis.
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DOI：
10.1097/rli.0b013e31823cc75c
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发表时间：
2012-04
影响因子：
6.7
通讯作者：
Goertz D
中科院分区：
文献类型：
--
作者：
Wright C;Hynynen K;Goertz D
表征高强度聚焦超声（HIFU）在体外实现溶栓的能力，并研究该方法作为体内血栓闭塞动脉血流恢复手段的可行性。所有实验均得到机构动物护理委员会的批准。使用 1.51MHz 聚焦超声换能器进行溶栓，脉冲长度为 0.1-10 ms，声功率高达 300W。体外实验使用兔动脉血形成的血凝块进行，血凝块位于直径 2 毫米的管道中。进行了单位置和流量旁路再通实验。使用 30MHz 超声波评估体外凝块侵蚀，并使用过滤器和库尔特计数器测量碎片尺寸。体内血栓在兔子的股动脉中启动（n = 26）。监测暴露期间形成的气泡的空化信号。使用 23MHz 多普勒超声评估体内血流恢复情况。在单个位置，体外凝块侵蚀体积随着暴露功率和脉冲长度的增加而增加，碎片尺寸随着脉冲长度的增加而减小。流量旁路实验实现了 99.2% 的凝块侵蚀，其中 1.1% 的碎片尺寸超过 0.5 毫米。在体内，10ms 脉冲与出血相关，但在 1ms 时，可以在 6/10 的血栓中实现部分血流恢复，其中只有 1/10 显示出血迹象。在所有情况下，溶栓仅在存在空洞的情况下发生。在没有溶栓剂的情况下，HIFU 溶栓作为一种恢复血栓闭塞动脉部分血流的方法是可行的。这种方法出血的可能性需要进一步研究。
To characterize the ability of high intensity focused ultrasound (HIFU) to achieve thrombolysis in vitro and investigate the feasibility of this approach as a means of restoring blood flow in thrombus occluded arteries in vivo. All experiments were approved by the institutional animal care committee. Thrombolysis was performed with a 1.51MHz focused ultrasound transducer with pulse lengths of 0.1–10 ms and acoustic powers up to 300W. In vitro experiments were performed with blood clots formed from rabbit arterial blood and situated in 2mm diameter tubing. Both single location and flow-bypass recanalization experiments were conducted. In vitro clot erosion was assessed with 30MHz ultrasound, with debris size measured with filters and a Coulter counter. In vivo clots were initiated in the femoral arteries of rabbits (n = 26). Cavitation signals from bubbles formed during exposure were monitored. In vivo flow restoration was assessed with 23MHz Doppler ultrasound. At a single location, in vitro clot erosion volumes increased with exposure power and pulse length, with debris size reducing with increasing pulse length. Flow bypass experiments achieved 99.2% clot erosion with 1.1% of debris above 0.5mm in size. In vivo, 10ms pulses were associated with bleeding, but at 1ms it was feasible to achieve partial flow restoration in 6/10 clots with only 1/10 showing evidence of bleeding. In all cases, thrombolysis occurred only in the presence of cavitation. HIFU thrombolysis is feasible as a means of restoring partial blood flow in thrombus occluded arteries in the absence of thrombolytic agents. The potential for bleeding with this approach requires further investigation.