PDF(Pubmed)
Abstract：
Photo-mediated ultrasound therapy (PUT) is a novel therapeutic technique based on the combination of ultrasound and laser. The underlying mechanism of PUT is the enhanced cavitation effect inside blood vessels. The enhanced cavitation activity can result in bio-effects such as reduced perfusion in microvessels. The reduced perfusion effect in microvessels in the eye has the potential to control the progression of eye diseases such as diabetic retinopathy and age-related macular degeneration. Several in vivo studies have demonstrated the feasibility of PUT in removing microvasculature in the eye using rabbit eye model and vasculature in the skin using rabbit ear model. Numerical studies using a bubble dynamics model found that cavitation is enhanced during PUT due to the dramatic increase in size of air/vapor nuclei in blood. In addition, the study conducted to model cavitation dynamics inside a blood vessel during PUT found stresses induced on the vessel wall during PUT are higher than that at normal physiological levels, which may be responsible for bio-effects. The concentration of vasodilators such as nitric oxide and prostacyclin were also found to be affected during PUT in an in vitro study, which may limit blood perfusion in vessels. The main advantage of PUT over conventional techniques is non-invasive, precise, and selective removal of microvessels with high efficiency at relatively low energy levels of ultrasound and laser, without affecting the nearby structures. However, the main limitation of vessel rupture/hemorrhage needs to be overcome through the development of real-time monitoring of treatment effects during PUT. In addition to the application in removing microvessels, PUT-based techniques were also explored in treating other diseases. Studies have found a combination of ultrasound and laser to be effective in removing blood clots inside veins, which has the potential to treat deep-vein thrombosis. The disruption of atherosclerotic plaque using combined ultrasound and laser was also tested, and the feasibility was demonstrated.
摘要：
光介导超声治疗（PUT）是一种基于超声和激光结合的新型治疗技术。PUT的潜在机制是血管内空化效应的增强。增强的空化活性可以导致生物效应,例如减少微血管中的灌注。眼睛微血管中灌注效应的降低具有控制眼部疾病如糖尿病性视网膜病变和年龄相关性黄斑变性的进展的潜力。一些体内研究已经证明了PUT在使用兔眼模型去除眼睛中的微脉管系统和使用兔耳模型去除皮肤中的脉管系统中的可行性。使用气泡动力学模型进行的数值研究发现，由于血液中空气/蒸气核的大小急剧增加，因此在PUT过程中空化现象会增强。此外,对PUT过程中血管内空化动力学进行建模的研究发现，PUT过程中血管壁上引起的应力高于正常生理水平，这可能是生物效应的原因。在体外研究中，在PUT期间，还发现血管扩张剂如一氧化氮和前列环素的浓度受到影响，这可能会限制血管中的血液灌注。与传统技术相比，PUT的主要优势是非侵入性的，精确，以及在相对较低能量水平的超声和激光下高效选择性去除微血管，不会影响附近的建筑。然而,需要通过在PUT期间实时监测治疗效果来克服血管破裂/出血的主要限制.除了在去除微血管中的应用外，还探索了基于PUT的技术在治疗其他疾病中的应用。研究发现，超声波和激光的组合可以有效清除静脉内的血凝块，有可能治疗深静脉血栓形成。还测试了使用超声和激光组合的动脉粥样硬化斑块的破坏，并论证了可行性。
