EVALUATION OF LASERS IN THE CARDIOVASCULAR SYSTEM

这项建议的目的是研究激光的影响， 动脉粥样硬化和血栓形成闭塞的动脉再通。 的 益处以及副作用将立即进行评估， 在各种动物模型中激光再通后的长期时间， 还将评估激光对心肌的影响， 用于希氏束和心律失常病灶消融。 激光已被证明可以再通血管阻塞， 通过中断狗的希氏束来实现完全性心脏传导阻滞。 然而，在这方面， 尽管有初步结果，但仍有几个问题没有得到回答：1） 什么是理想的激光波长的再通和心肌 蒸发; 2）温度对动脉有什么影响， 周围组织; 3）是否产生组织碎片; 4）将 光学特性的表征提高了激光器的应用; 5） 发色团是否会增强激光能量的局部化， 安全性; 6）激光应用的血栓形成潜力; 7）可以 光纤的设计应减少穿孔，8）是否有足够的通道 在人类中制造;如果是这样，这些专利将保留多久; 9）可以 激光器可用作生物探针， 再通 三个领域的调查将试图解决这些问题：1） 体外研究将调查基本的激光-组织相互作用。 这些 包括对正常人组织学、生物化学和光学研究， 动脉粥样硬化和心肌的最佳选择 蒸发的波长和参数。 发色团将用于 加强这一进程。 这些数据将允许光学 这些组织的特征，从而使激光生物 探针 温度记录和热电偶将用于测量温度 动脉再通期间的变化，以评估对 周围组织 碎片将被收集和测量。 2)体内 动物研究将包括各种光纤装置的测试， 评价再通和希氏束消融技术。 3)临床 试验将提供关于血管通道的充分性和寿命的数据 用于外周动脉闭塞的患者。 本研究将 利用血管镜、血管造影和生理学评价来评估 维持流向闭塞性血管疾病区域的血流。

The objective of this proposal is to study the effects of laser recanalization in arteries occluded by atherosclerosis and thrombosis. The benefits as well as the side effects will be evaluated in the immediate and long-term periods after laser recanalization in various animal models and in man. Also evaluation of the laser effects on myocardial muscle will be done for purposes of His Bundle and arrhythmia foci ablation. The laser has been shown to recanalize vascular obstructions and to create complete heart block by interruption of His Bundle in dogs. However, despite the preliminary results, several questions remain unanswered: 1) What is the ideal laser wavelength for recanalization and myocardial muscle vaporization; 2) What effect does temperature have on the artery and surrounding tissues; 3) Is there production of tissue debris; 4) Will characterization of the optical properties improve laser applications; 5) Will chromophores enhance laser energy localization and increase its safety; 6) What is the thrombogenic potential of laser applications; 7) Can optical fibers be designed to reduce perforations, 8) Can adequate channels be made in humans; if so, will these remain patent and for how long; 9) Can the laser be used as a biological probe to identify tissue during recanalization. Three areas of investigation will attempt to address these questions: 1) In vitro studies will investigate basic laser-tissue interactions. These include histologic, biochemical and optical studies of normal and atherosclerotic arteries, and cardiac muscle for selection of the optimal wavelength and parameters for vaporization. Chromophores will be used to enhance this process. These data will allow for the optical characterization of these tissues, thus making the laser a biological probe. Thermography and thermocouples will be used to measure temperature changes during arterial recanalization to assess thermal injury to the surrounding tissue. Debris will be collected and measured. 2) In vivo animal studies will include testing of various optical fiber devices to evaluate recanalization and His Bundle ablation techniques. 3) A clinical trial will provide data on the adequacy and longevity of vascular channels made in patients with occluded peripheral arteries. This study will utilize angioscopic, angiographic and physiologic evaluation to assess the maintenance of blood flow to areas of occlusive vascular disease.