Mudra H, Blasini R, Regar E, Klauss V, Rieber J, Theisen K
Medical Clinic, Ludwig-Maximilians University of Munich, Germany.
Coron Artery Dis. 1993 Sep;4(9):791-9. doi: 10.1097/00019501-199309000-00006.
Coronary stenting is an effective method for the treatment of acute coronary dissection and restenosis. In the comprehensive assessment of restenosis and of the complex interaction between coronary stent and vessel wall, coronary arteriography has significant limitations. Intravascular ultrasound as a high-resolution tomographic imaging method is a promising tool for resolving these limitations.
A 3.5, 5.0 or 5.5F, 20 MHz multi-element ultrasound catheter was used in 27 patients who had received a Palmaz-Schatz coronary stent for the treatment of symptomatic coronary dissection. Intravascular ultrasound study was performed during routine follow-up arteriography at 3-10 months in all 27 patients and had also been performed in four patients during stent deployment. Four patients with restenosis within the stent were re-investigated 3 months later after repeat angioplasty.
Complete analysis of the stented coronary segment could be performed in 34 out of 35 studies (97%); no adverse effects occurred. The three layer appearance of the vessel wall was not discernible in most patients because of a complex and often eccentric lesion surrounding the stent resulting in an asymmetrical arrangement of stent filaments. The beginning and the end of the stent, the central strut, and the overlap of a double stent could be well assessed. Luminal diameters ranged from 1.95 to 4.15 mm and cross-sectional areas from 3.83 to 10.85 mm2. Correlations with quantitative arteriography revealed r-values of 0.58 for diameter and 0.59 for area. A stent-covering layer, indicative of neointima, was clearly visible in all patients during follow-up arteriography with a diameter of 0.10-0.95 mm (mean 0.25 +/- 0.15 mm), which resulted in a reduction of 2-63% in the cross-sectional area of the vessel. This layer did not exceed a thickness of 0.4 mm in asymptomatic patients.
This study demonstrates the safe and feasible application of intravascular ultrasound in patients with stented coronary lesions. Differences between the angiographic and ultrasonic measurements are presumably the result of the limitations of radiography in complex and eccentric lesions. Intracoronary ultrasound provides a unique comprehensive assessment of stent expansion, neointimal proliferation, and restenosis mechanisms. Thus, intravascular ultrasound may also have implications regarding the indication for, and optimal deployment of, intracoronary stents.
冠状动脉支架置入术是治疗急性冠状动脉夹层和再狭窄的有效方法。在对再狭窄以及冠状动脉支架与血管壁之间复杂相互作用的综合评估中，冠状动脉造影存在显著局限性。血管内超声作为一种高分辨率断层成像方法，是解决这些局限性的有前景的工具。
对27例因有症状的冠状动脉夹层而接受帕尔马兹-施查茨冠状动脉支架治疗的患者，使用3.5、5.0或5.5F、20MHz的多阵元超声导管。在所有27例患者常规随访血管造影时于3至10个月进行血管内超声研究，并且在4例患者的支架置入过程中也进行了该研究。对4例支架内再狭窄患者在重复血管成形术后3个月再次进行研究。
35项研究中的34项（97%）能够对置入支架的冠状动脉节段进行完整分析；未发生不良反应。由于支架周围存在复杂且常为偏心性病变，导致支架丝排列不对称，大多数患者无法辨别血管壁的三层结构。支架的起始端和末端、中央支柱以及双支架的重叠部分能够得到很好的评估。管腔直径范围为1.95至4.15mm，横截面积为3.83至10.85mm²。与定量血管造影的相关性显示，直径的r值为0.58，面积的r值为0.59。在随访血管造影期间，所有患者均清晰可见一层指示新生内膜的支架覆盖层，其直径为0.10至0.95mm（平均0.25±
0.15mm），导致血管横截面积减少2%至63%。在无症状患者中，该层厚度不超过0.4mm。
本研究证明了血管内超声在置入冠状动脉支架病变患者中应用的安全性和可行性。血管造影测量与超声测量之间的差异可能是由于放射摄影在复杂和偏心病变中的局限性所致。冠状动脉内超声对支架扩张、新生内膜增殖和再狭窄机制提供了独特的综合评估。因此，血管内超声可能对冠状动脉支架的适应证和最佳置入也有影响。
