Ye B, Abela G S
Institute for Prevention of Cardiovascular Disease, New England Deaconess Hospital, Harvard Medical School, Boston, Massachusetts 02215.
Lasers Surg Med. 1993;13(4):393-404. doi: 10.1002/lsm.1900130402.
Improved detection of plaque during cardiovascular procedures could enhance the outcome of diagnosis and therapy. We evaluated a new method to stain plaque using a special intravenous preparation of beta-carotene (beta-C) in an in vivo model. beta-C was used to enhance the absorption coefficient of plaque and decrease the laser-induced fluorescence emission. Using this approach the difference in fluorescence emission was accentuated between normal artery and atherosclerotic plaque. Twenty-nine NZW rabbits were divided into five groups, each receiving a different intervention. This included the administration of beta-C to rabbits on a normal or a high cholesterol diet, with or without endothelial debridement. Aortae were examined grossly, by histology, and relative total fluorescence was detected at 886 sites using 488 nm or 514 nm laser excitation. At 488 nm excitation, unstained plaque attenuated total fluorescence twice as much as normal controls (7.55 +/- 1.46 vs. 15.06 +/- 3.12; P < 0.0001); beta-C stained plaque attenuated total fluorescence 17 times more than normal controls (0.89 +/- 0.29 vs. 15.06 +/- 3.12; P < 0.0001). Total fluorescence from unstained plaque was eight times greater than plaque stained with beta-C (7.55 +/- 1.46 vs. 0.89 +/- 0.29; P < 0.0001). Results obtained using 514 nm excitation were similar. The attenuation effect persisted up to 8 weeks following beta-C administration. Thus, beta-C stained plaque displayed fluorescence attenuation, which suggests that pretreatment with beta-C may greatly enhance plaque detection. This may be useful as a guide during plaque removal procedures.
在心血管手术过程中改进斑块检测可提高诊断和治疗效果。我们在体内模型中评估了一种使用特殊静脉注射用β-胡萝卜素（β-C）对斑块进行染色的新方法。β-C用于提高斑块的吸收系数并减少激光诱导的荧光发射。使用这种方法，正常动脉和动脉粥样硬化斑块之间的荧光发射差异得以凸显。29只新西兰白兔被分为五组，每组接受不同的干预措施。这包括给正常饮食或高胆固醇饮食的兔子注射β-C，有无内皮剥脱。对主动脉进行大体检查、组织学检查，并使用488 nm或514 nm激光激发在886个部位检测相对总荧光。在488 nm激发下，未染色的斑块使总荧光衰减的程度是正常对照的两倍（7.55±1.46对15.06±3.12；P<0.0001）；β-C染色的斑块使总荧光衰减的程度比正常对照大17倍（0.89±0.29对15.06±3.12；P<0.0001）。未染色斑块的总荧光比β-C染色斑块大8倍（7.55±1.46对0.89±0.29；P<0.0001）。使用514 nm激发获得的结果相似。β-C给药后，衰减效应持续长达8周。因此，β-C染色的斑块显示出荧光衰减，这表明用β-C预处理可能会大大提高斑块检测能力。这在斑块清除手术中可能很有用。
