Abstract

Purpose

High-intensity focused ultrasound (HIFU) is a potential noninvasive thermal ablation method for the treatment of peripheral artery disease. Dual-mode ultrasound arrays (DMUA) offer the possibility of simultaneous imaging and treatment. In this study, safety and feasibility of femoral artery robot-assisted HIFU/DMUA therapy was assessed.

Methods

In 18 pigs (∼50kg), angiography and diagnostic ultrasound were used to visualize diameter and blood flow of the external femoral arteries (EFA). HIFU/DMUA-therapy was unilaterally applied to the EFA dorsal wall using a 3.5 MHz, 64-element transducer, closed-loop-control was used to automatically adjust energy delivery to control thermal lesion formation. A continuous lesion of at least 25 mm was created by delivering 6–8 HIFU shots per imaging plane perpendicular to the artery spaced 1 mm apart. Directly after HIFU/DMUA-therapy and after 0, 3 or 14 days follow up, diameter and blood flow were measured and the skin was macroscopically examined for thermal damage. The tissue was removed for histological analysis.

Results

No complications were observed. The most frequently observed treatment effect was formation of scar tissue, predominantly in the adventitia and the surrounding tissue. No damage to the endothelium or excessive damage of the surrounding tissue was observed. There was no significant decrease in the mean arterial diameter after HIFU/DMUA-therapy.

Conclusion

HIFU/DMUA therapy successfully targeted the vessel walls of healthy porcine arteries, without causing endothelial damage or other vascular complications. Therefore, this therapy can be safely applied to healthy arterial walls in animals. Future studies should focus on safety and dose-finding in atherosclerotic diseased arteries.

中文翻译：

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机器人辅助高强度聚焦超声靶向动脉壁的安全性和可行性：一项临床前研究。

摘要

目的

高强度聚焦超声（HIFU）是一种潜在的无创热消融方法，用于治疗周围动脉疾病。双模超声阵列（DMUA）提供了同时成像和治疗的可能性。在这项研究中，评估了股动脉机器人辅助HIFU / DMUA治疗的安全性和可行性。

方法

在18头猪（约50公斤）中，使用血管造影和超声诊断来可视化股外动脉（EFA）的直径和血流。HIFU / DMUA治疗使用3.5 MHz，64元素换能器单方面应用于EFA背壁，采用闭环控制来自动调节能量传递以控制热病变的形成。通过在垂直于动脉且相距1 mm的每个成像平面上进行6–8个HIFU注射，可形成至少25 mm的连续病变。在HIFU / DMUA治疗后和随访0、3或14天后，立即测量直径和血流量，并宏观检查皮肤的热损伤。取出组织用于组织学分析。

结果

没有观察到并发症。最经常观察到的治疗效果是瘢痕组织的形成，主要在外膜和周围组织中。没有观察到内皮损伤或周围组织过度损伤。HIFU / DMUA治疗后平均动脉直径没有明显减少。

结论

HIFU / DMUA治疗成功地靶向了健康猪动脉的血管壁，而没有引起内皮损伤或其他血管并发症。因此，该疗法可以安全地应用于动物的健康动脉壁。未来的研究应集中在动脉粥样硬化病变动脉的安全性和剂量寻找上。