Emanuelsson H
Division of Cardiology, Sahlgrenska University Hospital, Göteborg, Sweden.
J Intern Med. 1995 Aug;238(2):111-9. doi: 10.1111/j.1365-2796.1995.tb00908.x.
Several intravascular techniques have been developed with the purpose of achieving optimal guidance for treatment during coronary angioplasty (PTCA). Although the coronary angiographic technique is well established, there are still some inherent limitations. Due to intimal rupture, tears, dissection and thrombus following PTCA treatment, angiography does not allow exact delineation of the true borders of the vessel. Coronary angioscopy is currently the most sensitive method to detect coronary thrombus and can also be used to classify atheromatous plaques. Furthermore, coronary dissection can be detected with more accuracy than with angiography. One limitation associated with angioscopy is the need to occlude the vessel during imaging, which may create myocardial ischaemia. Furthermore, there is presently no method for quantifying angioscopic findings. Intravascular ultrasound produces a cross-sectional image of the vessel, which permits analysis of the layers of the vascular wall. Characterization and classification of various types of plaque can be made because thrombus, lipid, fibrous tissue and calcium have different ultrasonic echogenicity. Flow velocity measurement with the Doppler technique is an interesting approach to the physiological assessment of coronary stenoses. Coronary flow reserve can be estimated with this method and monitoring of the flow signal following angioplasty will aid in the diagnosis of flow-limiting complications. The trans-stenotic pressure gradient is a valuable measure of the haemodynamic importance of a coronary lesion. Trans-stenotic gradients during maximal hyperaemia obtained with a miniaturized pressure transducer yield reliable information regarding the severity of the stenosis, and the pressure values may be used to calculate the relative coronary flow reserve. In conclusion, all of these intracoronary diagnostic techniques will to some extent play a role in the future of coronary angioplasty. Safety, cost and complexity are some of the factors which will determine the growth potential of each method.
为了在冠状动脉血管成形术（PTCA）期间实现治疗的最佳引导，已经开发了几种血管内技术。尽管冠状动脉血管造影技术已经成熟，但仍然存在一些固有的局限性。由于PTCA治疗后出现内膜破裂、撕裂、夹层和血栓形成，血管造影无法精确描绘血管的真实边界。冠状动脉血管镜检查是目前检测冠状动脉血栓最敏感的方法，也可用于对动脉粥样斑块进行分类。此外，与血管造影相比，冠状动脉夹层的检测准确性更高。血管镜检查的一个局限性是在成像过程中需要阻塞血管，这可能会导致心肌缺血。此外，目前还没有量化血管镜检查结果的方法。血管内超声可生成血管的横截面图像，从而能够分析血管壁的各层结构。由于血栓、脂质、纤维组织和钙具有不同的超声回声性，因此可以对各种类型的斑块进行特征描述和分类。利用多普勒技术测量流速是评估冠状动脉狭窄生理学的一种有趣方法。用这种方法可以估计冠状动脉血流储备，血管成形术后对血流信号的监测将有助于诊断血流受限并发症。跨狭窄压力梯度是衡量冠状动脉病变血流动力学重要性的一个有价值的指标。使用小型化压力传感器在最大充血时获得的跨狭窄梯度可提供有关狭窄严重程度的可靠信息，压力值可用于计算相对冠状动脉血流储备。总之，所有这些冠状动脉内诊断技术在未来的冠状动脉血管成形术中都将在一定程度上发挥作用。安全性、成本和复杂性是决定每种方法发展潜力的一些因素。
