Deckelbaum L I, Stetz M L, O'Brien K M, Cutruzzola F W, Gmitro A F, Laifer L I, Gindi G R
Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut.
Lasers Surg Med. 1989;9(3):205-14. doi: 10.1002/lsm.1900090303.
Laser-induced fluorescence (LIF) spectroscopy can only be used for laser angioplasty guidance if high-power laser ablation does not significantly alter the pattern of tissue fluorescence. Although the spectra of normal and atherosclerotic arteries differ, the change in fluorescence spectra following laser angioplasty has not been well studied. Therefore, the purpose of this study was to assess whether laser-induced fluorescence spectroscopy could guide selective laser ablation of atherosclerotic plaque and, if so, to develop a quantitative LIF score that could be used to control a "smart" laser angioplasty system. Baseline LIF spectroscopy of 50 normal and 50 atherosclerotic human aortic specimens was performed using an optical fiber coupled to a He-Cd laser and optical multichannel analyzer. LIF was then serially recorded during erbium:YAG laser ablation of 27 atherosclerotic specimens. Laser ablation was terminated when the arterial LIF spectrum visually appeared normal. Histologic analysis revealed a mean initial plaque thickness of 1,228 +/- 54 microns and mean residual plaque thickness of 198 +/- 27 microns. Ablation of the media occurred in only three specimens. A discriminant function was derived to discriminate atherosclerotic from normal tissue for computer guidance of laser angioplasty. The LIF score, derived from stepwise multivariate linear regression analysis of the LIF spectra, correctly classified 93% of aortic specimens. The spectra obtained from the atherosclerotic specimens subjected to fluorescence-guided laser revealed a change in score from "atherosclerotic" to "normal" following plaque ablation. Seven atherosclerotic specimens were subjected to laser angioplasty with on-line computer control using the LIF score. Mean initial plaque thickness was 1,014 +/- 86 microns, and mean residual plaque thickness was 78 +/- 29 microns. There was no evidence of ablation of the media. Therefore, LIF guidance of laser ablation resulted in minimal residual plaque without arterial perforation. These findings support the feasibility of an LIF-guided laser angioplasty system for selective atherosclerotic plaque ablation.
只有在高功率激光消融不会显著改变组织荧光模式的情况下，激光诱导荧光（LIF）光谱才可用于激光血管成形术的引导。尽管正常动脉和动脉粥样硬化动脉的光谱有所不同，但激光血管成形术后荧光光谱的变化尚未得到充分研究。因此，本研究的目的是评估激光诱导荧光光谱是否能够引导对动脉粥样硬化斑块进行选择性激光消融，如果可以，则开发一种定量LIF评分，用于控制“智能”激光血管成形术系统。使用与氦镉激光器和光学多通道分析仪耦合的光纤，对50个正常和50个动脉粥样硬化的人体主动脉标本进行基线LIF光谱分析。然后，在对27个动脉粥样硬化标本进行铒：钇铝石榴石激光消融期间，连续记录LIF。当动脉LIF光谱在视觉上看起来正常时，停止激光消融。组织学分析显示，初始斑块平均厚度为1228±54微米，残余斑块平均厚度为198±27微米。仅在三个标本中发生了中膜消融。推导了一种判别函数，用于区分动脉粥样硬化组织和正常组织，以指导激光血管成形术的计算机操作。从LIF光谱的逐步多元线性回归分析得出的LIF评分正确分类了93%的主动脉标本。在接受荧光引导激光治疗的动脉粥样硬化标本中获得的光谱显示，斑块消融后评分从“动脉粥样硬化”变为“正常”。使用LIF评分对7个动脉粥样硬化标本进行了在线计算机控制的激光血管成形术。初始斑块平均厚度为1014±86微米，残余斑块平均厚度为78±29微米。没有中膜消融的证据。因此，激光消融的LIF引导导致残余斑块最小且无动脉穿孔。这些发现支持了LIF引导的激光血管成形术系统用于选择性动脉粥样硬化斑块消融的可行性。
