血管超声评估颈动脉粥样硬化斑块易损性的可行性研究

目的前瞻性研究血管超声评估颈动脉粥样硬化斑块易损性的可行性。方法连续纳入2019年3月至10月苏州大学附属第一医院神经外科行颈动脉内膜切除术(CEA)患者44例(46例次),术前常规行颈部血管超声(CDU)、CT血管成像、CT灌注成像和(或)DSA检查,术后观察斑块大体形态并行组织病理苏木素-伊红(HE)及免疫组织化学CD31染色。设定斑块易损分数评分标准:依据CDU评估斑块形态、回声、纤维帽完整与否、有无溃疡、血管狭窄程度分别赋值以0~3分,计算责任斑块的易损分数,并以易损分数>4分为易损斑块,易损分数≤4分为稳定斑块;依据术后组织病理HE结果,将其分为易损组(36例次)和稳定组(10例次);根据术前6个月内是否发生缺血性卒中,将所有患者分为卒中患者33例(35例次)与非卒中患者11例(11例次);依据免疫组织化学CD31染色评估斑块内微血管密度。采用独立样本t检验、Wilcoxon秩和检验和χ2检验比较两组患者一般资料、实验室检查、临床表现、易损分数及易损斑块比率的差异;采用Kappa值评价CDU与组织病理HE评估斑块易损性的一致性。结果(1)一般临床资料:易损组与稳定组美国国立卫生研究院卒中量表评分、神经系统表现差异均有统计学意义(均P<0.05)。(2)易损分数:易损组明显高于稳定组[6.00(5.00,7.00)]分比4.00(4.00,4.25)分],差异有统计学意义(Z=-4.031,P<0.01);卒中患者易损分数明显高于非卒中患者[6.00(5.00,7.00)分比4.00(4.00,5.00)]分,差异有统计学意义(Z=-3.116,P=0.002)。(3)诊断效能:CDU易损分数判断易损斑块的敏感度为88.9%,特异度为8/10,阳性预测值为94.1%,阴性预测值为8/12,约登指数为68.9%,CDU与组织病理HE评估斑块易损性的一致性较强(Kappa=0.642,P<0.01)。(4)新生血管形成:免疫组织化学CD31染色见易损斑块内新生血管形成;易损组中微血管密度高于稳定组[(2.84±1.56)mm 2比(1.38±0.61)mm 2],差异有统计学意义(t=-4.507,P<0.01)。(5)易损斑块与缺血性卒中的关系:卒中患者中易损斑块比率高于非卒中患者[88.6%(31/35)比3/11;χ2=13.286,P<0.01]。结论运用血管超声判断斑块易损分数可准确、定量评估颈动脉斑块易损性,且易损斑块中可见新生血管形成,为临床诊断及精准治疗提供理论依据。

A feasibility study of Doppler ultrasonography in evaluating the vulnerability of carotid atherosclerotic plaque

Objective To investigate the feasibility of Doppler ultrasonography in evaluating the vulnerability of carotid atherosclerotic plaque prospectively.Method A total of 44 patients(46 plaques)who performed carotid endarterectomy were continuously enrolled in the Department of Neurosurgery of the First Affiliated Hospital of Soochow University from March 2019 to October 2019.Several examinations such as carotid Doppler ultrasonography(CDU),CT angiography,CT perfusion imaging,and/or digital subtraction angiography were scheduled conventionally before surgery.Pathologic examination,including the plaque morphology,histopathologic hematoxylin eosin(HE)staining,and immunohistochemical CD31 staining,were evaluated after surgery.The plaque vulnerable score was calculated based on the parameters of CDU consisting of plaque morphology,characteristic of echo,fiber cap integrity,presence of ulcer,degree of vascular stenosis,assigned with 0 to 3 points,respectively.The plaque was defined as the vulnerable plaque if vulnerable score was more than 4,otherwise,the plaque was the stable plaque.Then the plaques were divided into vulnerable group(n=36)and stable group(n=10)according to the pathological results.The patients were divided into the stroke group(n=33)and the non-stroke group(n=11)based on the incidence of ischemic stroke within the last 6 months.The evaluation of neovascularization in the plaque was referring to the immunohistochemical CD31 staining.The independent-sample t test,Wilcoxon rank-sum test,andχ2 test were used to compare the differences between the two groups in general data,laboratory tests,clinical symptoms,vulnerable scores,and the rates of vulnerable plaques.Kappa value was used to evaluate the consistency between CDU and histopathological HE staining in the evaluation of plaque vulnerability.Results(1)The differences in the National Institute of Health stroke scale score and neurological symptoms between the vulnerable group and stable group were statistically significant(all P<0.05).(2)The vulnerable score was significantly different between the vulnerable group and stable group(6.00[5.00,7.00]scores vs.4.00[4.00,4.25]scores,P<0.01),and between the stroke group and non-stroke group(6.00[5.00,7.00]scores vs.4.00[4.00,5.00]scores,P=0.002).(3)Diagnostic efficacy:compared with histopathologic results,the sensitivity and specificity of CDU were respectively 88.9%and 8/10,positive predictive value was 94.1%,negative predictive value was 8/12,and the Youden index was 68.9%.The consistency between CDU and histopathological HE staining was strong(Kappa=0.642,P<0.01).(4)Neovascularization:immunohistochemical CD31 staining showed neovascularization in vulnerable plaque;the microvessel density in vulnerable group was higher than that in stable group([2.84±1.56]mm 3 vs.[1.38±0.61]mm 3).(5)The relationship between plaque vulnerability score and ischemic stroke:the rates of vulnerable plaques in the stroke group was higher than that in the non-stroke group(88.6%[31/35]vs.3/11;χ2=13.286,P<0.01).Conclusion The plaque vulnerable score evaluating by vascular ultrasound can accurately and quantitatively assess the vulnerability of carotid plaques,and angiogenesis can be observed in the vulnerable plaque,which provides a theoretical basis for clinical diagnosis and accurate treatment.