血管内超声显像在冠心病支架植入术中的应用

目的探讨血管内超声在冠心病支架植入中的作用。方法50例患者的52处病变在支架植入前后分别用血管内超声进行定量和定性分析,并根据血管内超声标准决定支架的直径以及植入的终点,分析CAG和IVUS对支架植入终点判断的差异和最终获得的管腔面积大小的差别以及支架后管腔面积增大的机制。结果IVUS比CAG判断的平均支架直径大[(3.48±0.29)mmvs(3.36±0.33)mm,P=0.011],支架囊的最终峰值压力明显增大[(17.7±2.9)atmvs(12.8±2.4)atm,P<0.001],QCA测得的支架面积狭窄百分比减小(13.2%±6.6%vs16.6%±9.1%,P=0.044);首次高压扩张后支架满意率CAG达96.2%,而IVUS只有37.7%。IVUS指导后最终的球囊压力更高[(16.13±1.87)atmvs(12.62±2.61)atm,P<0.001],获得的管腔直径更大[(3.64±0.53)mmvs(3.31±0.57)mm,P<0.001],管腔面积也更大[(9.90±2.05)mm2vs(8.84±1.67)mm2,P<0.001],面积狭窄百分比更小(49.15%±9.03%vs54.24%±10.05%,P<0.001];所有患者支架的近段和远段CAG均未发现明显的狭窄。而IVUS却发现支架近段血管有39例(75.0%),远段血管有23(44.2%)例存在动脉粥样硬化斑块;支架植入后非脂质斑块较脂质斑块获得的管腔面积更大[(4.50±1.67)mm2vs(3.68±0.97)mm2,P<0.001],其中脂质斑块血管面积增大较非脂质斑块小1.30mm2,斑块压缩程度却增加0.48mm2。结论IVUS较CAG能更好地判断病变的性质,指导支架更好地选择,可获得更大的管腔面积,更小的面积狭窄百分比。     

慢性稳定性心绞痛患者冠状动脉临界病变斑块性质的血管内超声分析

目的探讨慢性稳定性心绞痛患者冠状动脉临界病变血管内超声斑块影像学特征。方法对慢性稳定性心绞痛患者行冠状动脉造影检查,对冠状动脉造影显示为临界病变者,行血管内超声检查,评估斑块特征。结果 163例冠状动脉临界病变患者中薄帽纤维粥样硬化斑块(TCFA)、厚帽纤维粥样硬化斑块(ThCFA)患者分别为37、50例。TCFA、ThCFA患者临床特征、冠状动脉分布情况差异无统计学意义;超过50%的临界病变血管在左冠状动脉前降支;ThCFA患者平均斑块负荷、斑块面积高于TCFA患者;ThCFA及TCFA患者斑块成分以纤维组织最多,其次为纤维脂肪组织和坏死核心成分,高密度钙化面积最低。TCFA患者最小管腔面积≤4.0mm2者占18.92%(7/37),显著高于ThCFA患者。结论慢性稳定性心绞痛冠状动脉临界病变ThCFA患者斑块负荷更重,管腔面积更大。TCFA患者最小管腔面积≤4.0mm2比例更高。     

计算机断层扫描血管成像检查对冠状动脉临界病变的诊断价值

目的探讨计算机断层扫描血管成像(CTA)检查对冠状动脉临界病变的诊断价值。方法收集2019年1月至2021年5月于皖南医学院附属太和医院行冠状动脉CTA和冠状动脉造影(CAG)检查的82例患者的临床资料,以CAG检查结果为金标准,分析CTA检查对冠状动脉临界病变的诊断效能。结果CAG检查共检出251处冠状动脉狭窄病变,其中轻度狭窄53处,中度狭窄137处,重度狭窄及闭塞病变61处。在CTA检查中,3处轻度狭窄病变未被检出,1处轻度狭窄病变被判断为中度狭窄病变,3处重度狭窄病变被判断为中度狭窄病变。CTA检查诊断冠状动脉临界病变的灵敏度为95.6%,特异度为93.9%,阳性预测值为94.9%,阴性预测值为94.7%,准确度为94.8%(P<0.01)。受试者操作特征(ROC)曲线的曲线下面积为0.903。在8例因中度狭窄且合并缺血症状的患者中,两种检查方法诊断的中度狭窄程度比较,差异无统计学意义(P>0.05)。结论CTA诊断冠状动脉临界病变准确、简便,具有较高的诊断价值,对于未明确冠状动脉介入检查和治疗指征的患者具有较高的筛查能力,值得临床推广。     

冠状动脉旁路移植术同期颈内动脉内膜剥脱术3例

我们于 2 0 0 0年 1月下旬至 2 0 0 0年 12月同期完成冠状动脉旁路移植 (ＣＡＢＧ)手术和颈内动脉内膜剥脱 (ＣＥＡ)手术 3例 ,现总结报道如下。临床资料　 3例病人中男 2例 ,年龄分别为 73、80岁 ;女1例 ,6 3岁。 2例因脑缺血症状、1例因不稳定心绞痛入院。颈动脉造影证实 ,2例男病人左颈内动脉狭窄分别为 4 0 %和2 0 % ,右颈内动脉狭窄分别为 90 %和 96 % ;女病人右颈动脉85 %狭窄 ,左颈内动脉长段串珠状狭窄 ,最狭窄处达 95 %。冠状动脉造影发现 2例为 3支血管病变 ,1例为 2支血管病变 ,狭窄均大于 70 %。追问病史 2例有劳累后心绞痛症状…     

血管内超声显像在诊断主动脉夹层动脉瘤中的应用

目的　评价血管内超声 (IVUS)显像在诊断主动脉夹层动脉瘤中的作用。　方法　选择血管外科收治的主动脉夹层动脉瘤患者 82例。评价IVUS在明确夹层真假腔、破口位置、末端部位、假腔内血栓、内脏动脉与真假腔的关系、内脏动脉的缺血原因和主动脉直径等方面的作用 ,并与CT、MRI、经胸超声 (TTE)、经食管超声 (TEE)、双功能超声 (Duplex)和动脉造影 (DSA)相对照。结果　通过IVUS发现的真假腔外侧壁的超声结构差异、真假腔外侧壁交界处的特征性改变和假腔内血栓可鉴别真假腔。IVUS可发现静态狭窄和动态狭窄等内脏动脉缺血的原因。IVUS对近端破口的检出率为 1 0 0 % ,高于CT(2 8% )、MRI(2 2 % )、TTE(2 % )和TEE(61 % ) (P <0 0 1 ) ;与DSA(88% )差异无显著性意义 (P >0 0 5)。IVUS对夹层末端的检出率为 1 0 0 % ,高于Duplex(2 1 % ) (P <0 0 1 ) ;与CT(89% )和MRI(86 % )差异无显著性意义 (P >0 0 5)。IVUS对内脏动脉的检出率为 98% ,高于CT(56 % )、MRI(57% )、Duplex(1 7% )和DSA(66 % ) (P <0 0 1 )。IVUS测得的主动脉直径与CT测量值的相关系数r=0 94(P <0 0 1 )。　结论　应用IVUS能够对主动脉夹层动脉瘤的全貌有比较全面的认识。在明确内脏动脉与真假腔的关系和内脏动脉的缺血原因方面 ,IVUS优     

冠状动脉计算机断层扫描血管成像对冠状动脉狭窄程度的诊断价值

目的探讨冠状动脉计算机断层扫描血管成像(CTA)技术对冠状动脉狭窄程度的诊断价值。方法收集2020年7月至2021年6月贵州医科大学附属兴义市人民医院收治的119例冠状动脉相关疾病患者的医学影像学资料。以冠状动脉血管造影(CAG)检查结果为诊断冠状动脉狭窄的“金标准”,评估CTA检查对冠状动脉狭窄的诊断效能。采用受试者工作特征(ROC)曲线分析CTA检查与CAG检查诊断冠状动脉狭窄的一致性。比较CTA与CAG检查对冠状动脉狭窄程度分级的评估情况,以及两种检查方法下冠状动脉狭窄情况的各项参数,包括外弹力膜(EEM)面积、最小管腔面积(MLA)、斑块面积(PA)、斑块负荷(PB)、斑块偏心指数(EI)、重构指数(RI)。结果CAG检查结果显示,119例冠状动脉相关疾病患者中,冠状动脉狭窄患者108例,非冠状动脉狭窄患者11例。CTA检查诊断冠状动脉狭窄的灵敏度为98.15%,特异度为72.23%,准确度为95.80%。CTA检查与CAG检查诊断冠状动脉狭窄具有良好的一致性(Kappa=0.739,P<0.01)。ROC曲线分析结果显示,CTA检查诊断冠状动脉狭窄的曲线下面积(AUC)为0.854(95%CI:0.673~1.000),对冠状动脉狭窄具有中等诊断价值。CTA检查与CAG检查对冠状动脉狭窄程度分级的评估情况、冠状动脉狭窄情况的评估参数比较,差异均无统计学意义(P>0.05)。结论CTA检查对冠状动脉狭窄具有较好的诊断价值,能够较为准确地评估冠状动脉狭窄程度,对冠状动脉狭窄情况与相关参数的诊断准确度均较高,且具有无创、重复性好、患者耐受度高等优势。     

血管内超声定位下主动脉夹层球囊开窗术的研究

目的　观察血管内超声 (IVUS)定位下主动脉夹层球囊开窗术的疗效。方法　制作犬降主动夹层模型 (n =8) ,在IVUS定位下行球囊开窗术。观察夹层远端血压和血流量以及真假腔血压差、面积和形态等的变化 ,评价球囊开窗术的有效性。比较IVUS测得的夹层长度与解剖学长度 ,测量开窗后残留夹层的长度 ,评价IVUS定位的准确性。结果　夹层远端血压和血流量由( 10 4± 8)mmHg和 ( 61± 12 )ml/min下降为夹层形成后的 ( 5 2± 2 0 )mmHg和 ( 2 7± 11)ml/min(P <0 .0 1) ,开窗后恢复为 ( 10 0± 8)mmHg和 ( 5 9± 12 )ml/min( P >0 .0 5 )。真假腔血压差在夹层形成后为 ( 5 9± 15 )mmHg ,开窗后为 ( 11± 4)mmHg( P <0 .0 1)。假腔面积和百分比由夹层形成后的 ( 5 6.4± 10 .3 )mm2 和 ( 64 .0± 10 .9) %下降为开窗后的 ( 4 4.5± 6.4)mm2 和 ( 5 1.3± 5 .8) %(P <0 .0 1)。夹层形态由凹陷型转变为开窗后的凸出型。IVUS测得的夹层长度与解剖学长度明显相关 (r=0 .97,P <0 .0 1)。开窗后残留夹层的长度≤ 3mm。结论　IVUS定位下的球囊开窗术是治疗夹层引起的外周动脉缺血的有效方法。     

血管内超声测量心外膜脂肪厚度与冠状动脉病变程度的相关性

目的评价血管内超声(IVUS)测量心外膜脂肪厚度(EAT)与冠状动脉病变的相关性。方法收集92例接受冠状动脉IVUS患者,应用常规超声测量EAT,并用IVUS测算冠状动脉狭窄率及斑块类型,根据检查结果将患者分为冠状动脉疾病(CAD)组和非CAD组,再根据冠状动脉狭窄率将CAD组患者分为轻度病变亚组、中度病变亚组及严重病变亚组;比较各组EAT的差异,观察EAT与冠状动脉狭窄率、斑块类型以及CAD相关危险因素之间的关系。结果 CAD组EAT值为(6.54±1.21)mm,非CAD组为(4.98±1.33)mm,二者差异有统计学意义(t=5.12,P<0.01)。随着CAD病变程度的加重,轻度、中度及严重病变亚组间EAT值逐渐升高,两两比较差异均有统计学意义(P均<0.05)。软斑块亚组EAT较钙化斑块亚组[(7.16±1.00)mm vs(5.34±1.40)mm,F=0.085,P<0.05]及混合斑块亚组[(6.20±1.95)mm,F=0.005,P<0.01]明显升高。EAT是CAD的独立危险因子(Wald值5.057,P=0.028)。结论超声测量EAT与冠状动脉病变严重程度具有相关性,可用于CAD患者的筛查。     

颈动脉粥样硬化狭窄患者的斑块特征及斑块中内脏脂肪素的表达

目的研究颈动脉粥样硬化患者的斑块特征并探讨内脏脂肪素(visfatin)与斑块稳定性之间的关系。方法 56例颈动脉粥样硬化狭窄患者根据临床表现及发作时间分为有症状组和无症状组;HE染色及Masson染色观察斑块的病理学特征,并根据纤维帽厚度和脂质坏死核心大小将斑块分为稳定性斑块和不稳定性斑块;免疫组化染色观察2组斑块中visfatin的表达情况。结果 1有症状组不稳定性斑块的比例(67.74%)明显高于无症状组(36.00%),P0.05。2与稳定性斑块相比,不稳定性斑块的纤维帽较薄、脂质坏死核心较大及发生出血者比例较高:(49.87±8.75)μm比(74.54±6.80)μm(P0.001);(65.63±12.97)%比(31.81±5.13)%(P0.001);63.33%比30.77%(P0.05)。3不稳定性斑块visfatin表达的积分光密度值(84 165.47±9 183.12)明显高于稳定性斑块(55 694.08±4 818.57),P0.001。结论 1斑块的不稳定性与动脉粥样硬化临床症状的发生密切相关;2纤维帽厚度、脂质坏死核心大小及出血在斑块的稳定性中发挥着重要作用;3 visfatin与动脉粥样硬化形成和斑块的不稳定性有关。     

游离三碘甲腺原氨酸水平与冠状动脉斑块虚拟组织学血管内超声容积参数的关系及其预测斑块性质的价值

目的 观察血清游离三碘甲腺原氨酸（FT3）水平与冠状动脉斑块虚拟组织学血管内超声（VH-IVUS）容积参数的关系及其预测斑块性质的价值。方法 收集66例接受冠状动脉造影及VH-IVUS检查的冠状动脉粥样硬化性心脏病（CHD）患者,通过分析其VH-IVUS检查结果获得斑块容积兴趣段的容积参数,包括坏死核心（NC）容积百分比、钙化组织（DC）容积百分比、纤维组织（FI）容积百分比、纤维脂肪组织（FF）容积百分比及斑块体积,并评价斑块是否为炎性薄纤维帽粥样硬化斑块（TCFA）。依据FT3水平中位数将患者分为高FT3组及低FT3组,比较组间斑块容积兴趣段容积参数的差异,并采用受试者工作特征（ROC）曲线分析以FT3预测TCFA的效能。结果全部患者血清FT3为2.94～6.40mmol/L,中位数4.55mmol/L。低、高FT3组各33例,各有11例、5例存在TCFA斑块。低FT3组FI容积百分比低于高FT3组（P<0.05）,其余参数组间差异均无统计学意义（P均>0.05）。低FT3组TCFA斑块占比高于高FT3组（P<0.01）。ROC曲线显示,FT3水平预测TCFA的曲...     

冠状动脉周围脂肪CT衰减与斑块类型的关系

目的观察冠状动脉周围脂肪组织(PCAT)CT衰减与斑块类型之间的关系。方法选取101例冠心病患者共196个斑块,包括非钙化斑块55个(A组)、混合斑块70个(B组)、钙化斑块71个(C组),比较3组斑块解剖特性指标及PCAT CT值,分析斑块周围PCAT CT值的影响因素,观察其与斑块中高衰减成分百分比之间的相关性。结果 3组间斑块最大横截面积、斑块体积、重构指数、病变狭窄程度、斑块中高衰减成分百分比、斑块平均CT值差异均有统计学意义(P均0.05);A、B、C组斑块中高衰减成分百分比、平均CT值及PCAT CT值均依序增加,两两比较差异均有统计学意义(P均0.05)。PCAT CT值与斑块中高衰减成分百分比呈正相关(r=0.677,P0.05)。斑块中高衰减成分百分比是PCAT CT值升高的独立影响因素(OR=1.041,P0.001)。结论伴随冠状动脉粥样硬化进展,病变周围PCAT发生细胞组成成分及间质纤维化等组织重塑,影像学表现为CT值逐渐增加。     

Silent coronary atheromatosis in type 1 diabetic patients and its relation to long-term glycemic control

Type 1 diabetic patients have a pronounced risk of premature coronary artery disease and death. We sought to evaluate the prevalence of silent coronary atheromatosis and to evaluate the relation between coronary atheromatosis and glycemic control. Coronary atheromatosis was evaluated in type 1 diabetic patients with no symptoms of coronary artery disease by exercise electrocardiogram (ECG) in 39 patients and quantitative coronary angiography and by intravascular ultrasound (IVUS) examinations in 29 patients. The findings from the IVUS examinations were related to mean HbA(1c) collected prospectively over 18 years. Abnormal exercise ECGs were found in 15% of patients, and angiographic diameter stenosis of >50% in one or more of the main coronary arteries was found in 34% of patients. All patients examined with intracoronary ultrasound had developed atherosclerotic plaques with an increased intimal thickness (>0.5 mm) in one or more of the coronary arteries. Coronary artery plaque formation, as judged by ultrasound, was significantly related to mean HbA(1c) during 18 years (P < 0.05) after adjustment for total cholesterol and age. This study demonstrates a high prevalence of silent coronary atheromatosis in type 1 diabetic patients with no symptoms of coronary heart disease. Long-term glycemic control was shown to be associated with coronary atheromatosis.     

Virtual histology and color flow intravascular ultrasound in peripheral interventions

The quality and interpretation of intravascular ultrasound (IVUS) imaging has been revolutionized in recent years by two new and major advances: virtual histology and color flow IVUS. Virtual histology intravascular ultrasound (VHIVUS) is a catheter-based technology where IVUS is generated from the transducer on the catheter tip and the reflected signals from the artery wall produce a color-coded map of the arterial disease. Different histological constituents of the plaque produce different reflected signals and these are assigned different colors (dark green, fibrous; yellow/green, fibrofatty; white, calcified; red, necrotic lipid core plaque). This color-coded map assists the interventionalist in understanding more fully how the lesion will behave at the moment of treatment, whether it will resist complete stent deployment or be liable to embolization. Originally introduced for coronary interventions, VHIVUS is now being applied to peripheral situations. Because it provides a detailed and close-proximity view of plaque, its potential to improve the safety and efficacy of carotid endoluminal repair is stimulating substantial interest. Similarly, color flow IVUS provides greater understanding for the operator of blood flow, and the interface between the vessel wall and the blood stream, lumen size, and success of treatment. Color flow IVUS does not use the Doppler effect, but creates real-time images that resemble color flow Doppler ultrasound. These two technological advances in IVUS have greatly improved the ability of the endovascular specialist to understand the arterial disease they are treating and to assess the completion of treatment.     

Effect and outcome of balloon angioplasty and stenting of the iliac arteries evaluated by intravascular ultrasound.

OBJECTIVES: To document the mechanism of percutaneous transluminal angioplasty (PTA) and stenting of the iliac arteries, and to relate the effect to patency. MATERIALS AND METHODS: Thirty-seven stenotic iliac arteries were examined by intravascular ultrasound (IVUS) and arteriography before and after PTA, and after stent deployment (n = 16). The patients were followed prospectively by duplex scanning at 3, 6, 12, 18 and 24 months after the intervention. RESULTS: The effect of PTA was established by both compression and stretching with the major contribution arising from stretching. There were differences in the effect of PTA dependent on plaque morphology: in homogeneous eccentric lesions, stretching contributed significantly more than compression to the luminal gain, while stretching and compression contributed equally in concentric or heterogeneous plaques. Stenting of the arteries had no effect on the free luminal area as measured by IVUS. The primary 1-year patency rate was 72%. The patency was related to the free luminal area and diameter and the heterogenicity of the plaque as evaluated by IVUS. The arteriographic measurements did not have any predictive value. CONCLUSION: IVUS was able to document the effect of PTA and stenting in the iliac arteries, and predict the outcome. The luminal gain and reduction in degree of stenosis seemed to be accomplished primarily by stretching of the arteries and to a lesser extent by plaque compression. Stenting did not change the IVUS measurements. Patency was related to the size of the free lumen and the heterogenicity of the plaque.     

Mechanisms of angioplasty in hemodialysis fistula stenoses evaluated by intravascular ultrasound.

Quantification of luminal dimensions and the mechanisms by which angioplasty (PTA) corrects non-atheroma venous fistula stenoses have been poorly studied. In 38 consecutive percutaneous balloon angioplasties of hemodialysis fistula stenoses, catheter-based, mechanically-rotated intravascular ultrasound (IVUS) images were obtained along with cineangiography. Images from 24 brachial vein, 11 central vein, 2 graft anastomoses, and 1 brachial artery were quantitatively and qualitatively evaluated. Semiautomated quantitative angiographic stenosis was 64 +/- 13% pre-PTA and reduced to 36 +/- 19% post-PTA (P less than 0.001). Post-PTA IVUS minimal lesion diameter and cross sectional area were 5.7 +/- 1.5 mm and 2.9 +/- 1.5 mm2, respectively. With IVUS, mechanisms observed were: vessel dissection in 16 (42%), arterial stretch (defined as vessel diameter: balloon diameter ratio = 0.75 to 1.0) in 19 (50%), and elastic recoil (defined as vessel diameter: balloon diameter ratio less than 0.75) in 19 (50%). Compared to angiography, morphologic information provided by IVUS were plaque composition (hard 11%, soft 89%), plaque topography (eccentric 94%, concentric 6%), thrombus (IVUS: N = 6 vs. angio: N = 1), dissection (IVUS: N = 16 vs. angio: N = 1). Thus, IVUS can evaluate lesion morphology and define luminal dimensions after angioplasty. Mechanisms of successful angioplasty of hemodialysis fistula stenosis occur primarily by vessel stretching and dissection, and significant post-PTA narrowing is due to elastic recoil.     

Arterial calcification increases in distal arteries in patients with peripheral arterial disease

The aim of this study was to determine if significant differences in plaque composition exist between the popliteal and tibial vessels in patients with severe peripheral arterial disease (PAD). Forty-four patients with PAD required either above-knee (n = 38), below-knee (n = 5), or through-knee (n = 1) amputation for pedal sepsis/gangrene. The 51 vessels (anterior tibial, n = 9; posterior tibial, n = 10; peroneal, n = 3; popliteal, n = 29) were obtained and underwent intravascular ultrasound (IVUS) evaluation ex vivo within 24 hr of amputation. Sequential IVUS data were obtained at known intervals throughout the vessel length and then analyzed with radiofrequency techniques for quantification of plaque composition, plaque volume, and total vessel volume. Plaque composition was categorized as fibrous, fibro-fatty, necrotic core, and dense calcium. Clinical data were obtained via review of electronic records at the time of amputation. Two-sided t-tests were performed to compare components within each plaque. Results are expressed as mean percentage +/- standard error of the mean. Tibial vessels had more dense calcium within these plaques than popliteal arteries (33.8 +/- 5.6% vs. 10.6 +/- 1.9%, p < 0.001). Consequently, distal vessels had less fibro-fatty and fibrous plaque than popliteal arteries (7.7 +/- 1.4% vs. 13.1 +/- 1.2%, p < 0.005; 42.4 +/- 4.7% vs. 61.4 +/- 2.2%, p < 0.001, respectively). Necrotic core plaque composition was found to be similar when comparing tibial versus popliteal arteries (16.1% vs. 14.9%, p = nonsignificant). Clinical factors including diabetes, hyperlipidemia, and chronic renal insufficiency were not associated with plaque composition differences using a univariate analysis. As we progress distally in the arterial tree of patients with PAD, calcium plaque content increases with decreasing burden of fibro-fatty plaque. Clinical and demographic factors, with the exception of smoking, were not found to be associated with atherosclerotic plaque composition.     

The contribution of inducible nitric oxide and cytomegalovirus to the stability of complex carotid plaque

Background: Although the association between inflammation and atherosclerosis is well established, the biologic events that trigger the local inflammatory response within plaque are not fully understood. Cytotoxic free radicals and infectious agents, both of which are associated with an inflammatory response, have previously been implicated in the initiation and progression of atherosclerosis. In this study, we analyzed carotid plaque for evidence of oxidative vascular injury by determining the presence and distribution of inducible nitric oxide synthase (iNOS) expression and nitrotyrosine formation and for evidence of infection with cytomegalovirus. Methods: Carotid plaque from 51 patients who underwent endarterectomy for either primary (n = 37) or recurrent (n = 14) stenosis were examined histologically (hematoxylin-eosin staining and Masson's trichrome staining) and with immunohistochemistry with specific antibodies to α–smooth muscle actin, macrophages (CD68), T-lymphocytes (CD3), and T-cell activation (human leukocyte antigen–DR). Twenty-eight specimens from patients with primary (n = 15) and recurrent (n = 13) stenosis were examined for the presence of iNOS and nitrotyrosine with immunohistochemistry and in situ hybridization (iNOS). Twenty-three additional specimens (22 primary, and 1 recurrent) were analyzed with antibodies to p53, cytomegalovirus, and the polymerase chain reaction (cytomegalovirus, n = 8). Results: Primary atherosclerotic lesions were either complex heterogenous cellular plaques (n = 29) or relatively acellular fibrous plaques (n = 8). Ten of 14 recurrent plaques were either complex or fibrous lesions, and the remaining four were typical of myointimal thickening. CD68-positive staining cells were detected in all specimens regardless of their structural morphology. CD3-positive cells were interspersed between macrophages in all heterogeneous cellular plaques and only infrequently noted in fibrous plaques. iNOS and nitrotyrosine immunoreactivity were detected in macrophages and smooth muscle cells in all complex and fibrous plaques and in two of four myointimal plaques. The presence of iNOS and nitrotyrosine in plaque correlated with the existence of symptoms in 80% of primary and 62% of recurrent lesions. Cytomegalovirus was detected in only two of 23 carotid specimens (9%). Conclusion: The association between ischemic cerebrovascular symptoms and iNOS and nitrotyrosine immunoreactivity in complex primary and recurrent carotid plaque and the infrequent occurrence of cytomegalovirus in primary carotid lesions suggests that ongoing free radical oxidative damage rather than viral infection may contribute to plaque instability in patients with complex and fibrous carotid plaques. (J Vasc Surg 1999;30:36-50.)     

256层螺旋CT血管造影术评价颈动脉溃疡斑块

目的探讨256层螺旋CTA评价颈动脉溃疡斑块的价值。方法回顾性分析136例颈动脉粥样硬化患者的256层螺旋CTA资料,观察斑块的分布情况及颈动脉管腔狭窄程度,并分析斑块的构成成分,重点分析其中溃疡斑块的相关情况,并分析溃疡斑块与临床症状的相关性。结果 136例患者中共发现颈动脉斑块452个,其中溃疡斑块78个,溃疡发生率为17.26%（78/452）,位于颈总动脉14个,分叉部32个,颈内动脉13个,颈外动脉19个;纤维斑块7个,脂肪斑块49个,钙化斑块3个,混合性斑块19个;溃疡斑块导致管腔轻、中、重度狭窄及闭塞分别为7、29、34和8个。溃疡斑块与脑缺血症状存在统计学关联（OR=3.433,P〈0.01）。结论 256层螺旋CTA可无创地评价颈动脉溃疡斑块的特征,具有较高应用价值。