Hausmann D, Mügge A, Daniel W G
Abteilung Kardiologie, Zentrum Innere Medizin und Dermatologie, Medizinische Hochschule Hannover.
Z Kardiol. 1994 Oct;83(10):717-26.
In addition to the degree of vessel obstruction and to the composition of the atheroma, the geometric shape of the plaque--in particular the presence of non-diseased wall segments--is an important factor in the pathophysiology and therapy of coronary heart disease. The relevance of the plaque shape has been emphasized by pathoanatomic studies in the late 1970s. The in vivo assessment of the plaque shape using coronary angiography has major limitations: The lumen silhouette obtained by angiography does not accurately reflect the histologic extent of the plaque due to compensatory vessel enlargement, atrophy of the media, and diffuse plaque accumulation. In contrast, intravascular ultrasound (IVUS) allows direct, cross-sectional visualization of the plaque. Although this method has a small, but definite acute risk, it provides the first technique for in vivo assessment of the extent and shape of coronary plaque. In agreement with prior pathoanatomic investigations, IVUS studies have confirmed that the majority of advanced coronary plaques are located eccentrically in the vessel and that non-diseased wall segments are often present in these lesions. Using IVUS imaging, it has also been proven that in vivo relaxation of advanced coronary stenoses by vasodilatory drugs is mainly based on expansion of the non-diseased wall segment. IVUS studies have also shown that the presence of non-diseased wall segments may be important for the effect of intracoronary interventions: Balloon angioplasty of eccentric coronary lesions often causes dilatation of the non-diseased wall segments; immediate and chronic elastic recoil of these vessel segments may diminish the lumen gain from this procedure. During directional coronary atherectomy IVUS imaging of the exact location and shape of the plaque may limit subintimal tissue retrieval and thereby also reduce restenosis.
除了血管阻塞程度和动脉粥样硬化的成分外，斑块的几何形状——特别是未病变的血管壁段的存在——是冠心病病理生理学和治疗中的一个重要因素。20世纪70年代后期的病理解剖学研究强调了斑块形状的相关性。使用冠状动脉造影对斑块形状进行体内评估存在重大局限性：由于血管代偿性扩张、中膜萎缩和斑块弥漫性积聚，造影获得的管腔轮廓不能准确反映斑块的组织学范围。相比之下，血管内超声（IVUS）可以直接对斑块进行横断面成像。尽管这种方法有小但明确的急性风险，但它提供了第一种用于体内评估冠状动脉斑块范围和形状的技术。与先前的病理解剖学研究一致，IVUS研究证实，大多数晚期冠状动脉斑块偏心位于血管内，并且这些病变中经常存在未病变的血管壁段。使用IVUS成像还证明，血管扩张药物使晚期冠状动脉狭窄在体内舒张主要基于未病变血管壁段的扩张。IVUS研究还表明，未病变血管壁段的存在可能对冠状动脉内介入治疗的效果很重要：偏心冠状动脉病变的球囊血管成形术常导致未病变血管壁段扩张；这些血管段的即时和慢性弹性回缩可能会减少该手术的管腔增益。在定向冠状动脉旋切术中，对斑块的确切位置和形状进行IVUS成像可能会限制内膜下组织的取出，从而也减少再狭窄。
