Arai Daisuke, Yamaguchi Susumu, Murakami Mamoru, Nakakuki Takuya, Fukuda Shunichi, Satoh-Asahara Noriko, Tsukahara Tetsuya
Department of Neurosurgery, National Hospital Organization, Kyoto Medical Center, Kyoto, Japan.
Acta Neurochir Suppl. 2011;112:15-9. doi: 10.1007/978-3-7091-0661-7_3.
Criteria to decide whether carotid endarterectomy (CEA) or carotid artery stenting (CAS) is the best mode of therapy in a specific case of cervical carotid stenosis have not been established. Overall, recent randomized clinical trials have reported that the effect on the prevention of stroke is not significantly different between CEA and CAS. CEA is more appropriate than CAS for soft atherosclerotic plaques, since such soft plaques are associated with a high incidence of ischemic complications during CAS. Therefore identification of the plaque type with noninvasive preoperative examinations plays an important role for selecting the suitable surgical method, CEA or CAS.
The objective of this study was to evaluate the association among findings of carotid ultrasonography (carotid US), black blood magnetic resonance imaging (BB-MRI), and the histopathological findings of plaque specimens removed during CEA, and secondly to consider whether these diagnostic tools are useful to predict the characteristics of carotid plaques.
We investigated a total of 25 consecutive patients who underwent CEA from November 2008 to June 2010 at Kyoto Medical Center. We examined carotid plaque in 17 patients employing both carotid US and BB-MRI, 7 patients by carotid US, and 1 patient by BB-MRI. The plaque echogenicity was qualitatively assessed as low, intermediate, or high, and the MR signal intensity of the carotid plaque was classified as low or high compared with the intensity of the ipsilateral sternocleidomastoid muscle. The plaque specimens were macroscopically and pathophysiologically classified as soft or hard plaque.
All low-echogenic plaques on carotid US were histologically soft plaques. The high-intensity plaques on T1-weighted imaging (T1WI) showed a tendency toward soft plaque. Thirteen of 14 plaques with high signal intensity on T1WI were morphologically soft. Eleven of 14 plaques with an intermediate echogenicity on carotid US were also morphologically soft.
The findings of carotid ultrasonography and BB-MRI are closely associated with the CEA specimen's morphology. Ultrasonography alone is insufficient to diagnose the plaque type accurately in some patients. Employing both carotid US and BB-MRI is useful for evaluating the characteristics of carotid plaque.
尚未确立在特定的颈段颈动脉狭窄病例中，决定颈动脉内膜切除术（CEA）或颈动脉支架置入术（CAS）哪种是最佳治疗方式的标准。总体而言，近期的随机临床试验报告称，CEA和CAS在预防卒中方面的效果并无显著差异。对于软动脉粥样硬化斑块，CEA比CAS更合适，因为此类软斑块在CAS期间发生缺血性并发症的发生率较高。因此，术前通过无创检查识别斑块类型对于选择合适的手术方法（CEA或CAS）起着重要作用。
本研究的目的是评估颈动脉超声检查（颈动脉超声）、黑血磁共振成像（BB-MRI）的检查结果与CEA期间切除的斑块标本的组织病理学检查结果之间的关联，其次是考虑这些诊断工具是否有助于预测颈动脉斑块的特征。
我们调查了2008年11月至2010年6月在京都医疗中心连续接受CEA的25例患者。我们对17例患者同时采用颈动脉超声和BB-MRI检查颈动脉斑块，7例患者仅通过颈动脉超声检查，1例患者仅通过BB-MRI检查。将斑块回声定性评估为低、中或高，并将颈动脉斑块的磁共振信号强度与同侧胸锁乳突肌强度相比分为低或高。对斑块标本进行宏观和病理生理分类，分为软斑块或硬斑块。
颈动脉超声检查显示的所有低回声斑块在组织学上均为软斑块。T1加权成像（T1WI）上的高信号强度斑块有倾向于软斑块的趋势。T1WI上14个高信号强度斑块中的l3个在形态上为软斑块。颈动脉超声检查中14个中等回声斑块中的11个在形态上也为软斑块。
颈动脉超声检查和BB-MRI的检查结果与CEA标本的形态密切相关。仅靠超声检查在某些患者中不足以准确诊断斑块类型。同时采用颈动脉超声和BB-MRI有助于评估颈动脉斑块的特征。
