Department of Radiology, University of Michigan Health System, Ann Arbor, Michigan, USA.
Microcirculation. 2012 Aug;19(6):501-9. doi: 10.1111/j.1549-8719.2012.00176.x.
Embolotherapy is a potential means to treat a variety of cancers. Our approach-gas embolotherapy-introduces the droplets upstream from the tumor and then acoustically activates them to form bubbles for occlusion-a process known as ADV. We wanted to provide the first optical documentation of ADV, lodged bubbles, or vessel occlusion in vivo.
We used the rat cremaster muscle for in vivo microscopy. Perfluorocarbon droplets were administered into the aortic arch. Ultrasound exposures in the cremaster induced vaporization. The cremaster was examined pre- and post-exposure for ADV-related effects. Two sets of experiments compared the effect of exposure in the capillaries versus the first order arteriole.
Bubbles that lodge following capillary exposure are significantly larger (76 μm mean length, 36 μm mean diameter) than those following feeder vessel exposure (25 μm mean length, 11 μm mean diameter). Despite the differing sizes in bubbles, the ratio of bubble length to the hydraulic diameter of all lodged bubbles was 2.11 (±0.65; n = 112), which agrees with theoretical predictions and experimental observations.
Our results provide the first optical evidence of targeted vessel occlusion through ADV. These findings could lay the groundwork for the advancement of gas embolotherapy.
栓塞疗法是治疗多种癌症的一种潜在手段。我们的方法——气体栓塞疗法——将液滴引入肿瘤上游，然后通过声学激活它们形成气泡以实现闭塞——这一过程被称为 ADV。我们希望提供 ADV、驻留气泡或血管闭塞的首例光学记录。
我们使用大鼠提睾肌进行体内显微镜检查。将全氟碳液滴注入主动脉弓。提睾肌中的超声暴露会引起蒸汽化。在暴露前后检查提睾肌以观察与 ADV 相关的影响。两组实验比较了毛细血管与一级小动脉暴露的效果。
毛细血管暴露后驻留的气泡明显更大（平均长度为 76μm，平均直径为 36μm），而供养血管暴露后驻留的气泡较小（平均长度为 25μm，平均直径为 11μm）。尽管气泡大小不同，但所有驻留气泡的气泡长度与水力直径之比均为 2.11（±0.65；n=112），这与理论预测和实验观察一致。
我们的结果提供了通过 ADV 进行靶向血管闭塞的首例光学证据。这些发现为气体栓塞疗法的发展奠定了基础。
