Evaluation of distal extracranial internal carotid artery by transoral carotid ultrasonography in patients with severe carotid stenosis

BACKGROUND AND PURPOSE: Conventional ultrasonography techniques do not allow visualization of the distal cervical segment of the internal carotid artery (ICA). In a study of patients with severe ICA stenosis, we performed transoral carotid ultrasonography (TOCU) to assess its ability to image this segment of the artery. METHODS: The study participants consisted of 20 consecutive patients who had severe carotid stenosis and who underwent carotid endarterectomy between 1999 and 2000. TOCU, conventional carotid ultrasonography, and cerebral angiography were prospectively performed before and after carotid endarterectomy. RESULTS: In all patients, the distal portion of the ICA could be clearly detected by B mode using TOCU and no plaque was observed. The diameter of the distal portion of the ICA significantly increased after carotid endarterectomy (3.9 +/- 0.5 mm [mean +/- SD]), compared with before (3.5 +/- 0.8 mm), when it was estimated by TOCU (P <.01). In seven patients, the postoperative diameter of the distal ICA increased >10%. The mean increase in the postoperative diameter was estimated to be 15.0 +/- 23.0% by TOCU, which significantly correlated with the findings (23.9 +/- 33.7%) based on cerebral angiography (P <.01). The diameter increased >10% postoperatively in 71% of the patients with the degree of cross-sectional stenosis >95% as shown by carotid ultrasonography and in 86% of the patients whose preoperative diameter was <3.0 mm. CONCLUSION: TOCU provides additional information regarding the characteristics of the distal ICA that can be obtained neither by conventional carotid ultrasonography nor by angiography.     

Incidental intracranial vascular pathology in patients investigated for carotid stenosis

The assessment of cervical and cranial carotid arteries for atherosclerotic disease is the second commonest referral for angiography in our neuroradiological department; in 1993 this accounted for approximately 17 % of the total cases. This is due to the resurgence of interest in endarterectomy for severe carotid stenosis. Although the degree of stenosis can usually be assessed adequately by duplex Doppler ultrasonography, angiography is still recommended as a preoperative examination. The intracranial vessels are visualised, which we consider important when planning vascular surgery. We present a prospective study of 100 patients referred for angiographic assessment of carotid stenosis. As well as giving information about the carotid bifurcation, angiography showed 9 patients to have aneurysms, 2 arteriovenous malformations and 15 severe intracranial atherosclerosis. We consider these “incidental” findings important for future management and highlight the need for thorough assessment of the intracranial vessels in these patients by angiography.     

Incidental intracranial vascular pathology in patients investigated for carotid stenosis

The assessment of cervical and cranial carotid arteries for atherosclerotic disease is the second commonest referral for angiography in our neuroradiological department; in 1993 this accounted for approximately 17% of the total cases. This is due to the resurgence of interest in endarterectomy for severe carotid stenosis. Although the degree of stenosis can usually be assessed adequately by duplex Doppler ultrasonography, angiography is still recommended as a preoperative examination. The intracranial vessels are visualised, which we consider important when planning vascular surgery. We present a prospective study of 100 patients referred for angiographic assessment of carotid stenosis. As well as giving information about the carotid bifurcation, angiography showed 9 patients to have aneurysms, 2 arteriovenous malformations and 15 severe intracranial atherosclerosis. We consider these incidental findings important for future management and highlight the need for thorough assessment of the intracranial vessels in these patients by angiography.     

Emergent combined intracranial thrombolysis and carotid stenting in the hyperacute management of stroke patients with severe cervical carotid stenosis

BACKGROUND AND PURPOSE: The timely re-establishment of intracranial perfusion, the effective prevention of early recurrent strokes, and the limitation of the incidence of reperfusion injury are the major factors that are key to successful treatment of patients with hyperacute stroke who had severe ipsilateral cervical internal carotid artery (ICA) stenosis. In an effort to reduce both the extent of the ongoing neurologic injury and the risk of early recurrent stroke, we have adopted an aggressive combined endovascular approach of intracranial thrombolysis and cervical carotid stent placement during the hyperacute phase. We report on the results of 5 such consecutive patients who presented to our center from January 2003 through January 2005. MATERIALS AND METHODS: From January 2003 through January 2005, 5 consecutive patients presented to our center with hyperacute strokes and severe ipsilateral cervical ICA stenosis. All were treated with emergent carotid stent placement and intra-arterial thrombolysis. The medical records were reviewed and summarized. RESULTS: One patient died. The remaining 4 patients had an average hospital stay of 4 days (range, 3-5 days) and a mean National Institutes of Health Stroke Scale (NIHSS) score of 2 (range, 0-3) at the time of discharge. With a mean clinical follow-up of 11 months (range, 6-24 months), all had excellent functional outcome with a modified Rankin score of 0 or 1. CONCLUSIONS: Data on emergent carotid stent placement in the hyperacute management of stroke are limited. The summarized experience in these 5 patients demonstrates the feasibility of this aggressive therapeutic strategy that may bring about a good outcome.     

超声对颈动脉内膜剥除前、后颅内外血流动力学变化的评价

目的:探讨彩色多普勒血流成像(CDFI)和经颅彩色多普勒血流成像(TCCDFI)评价颈动脉内膜剥除术(CEA)治疗前、后患者颅内外动脉血流动力学的变化。方法:用CDFI和TCCDFI分别对23例颅外段颈内动脉(EICA)狭窄患者CEA治疗前、后狭窄局部管径、收缩期峰值流速(PSV)及同侧大脑中动脉(MCA)、眼动脉(OA)CEA治疗前、后PSV、搏动指数(PI)和颅内侧支循环的建立情况进行分析。结果:EICA狭窄患者CEA术后原狭窄处内径、PVS及患侧MCA、OA的PSV、PI恢复正常,侧支循环关闭。结论:CDFI与TCCDFI结合可评价颈动脉狭窄患者行CEA治疗前、后颅内外动脉的血流动力学变化,对判断CEA的疗效具有重要的临床价值。     

Poststenotic signal attenuation on 3 D phase-contrast MR angiography: a useful finding in haemodynamically significant carotid artery stenosis

We performed blinded visual evaluation of MR angiography (MRA) films in 44 patients with unilateral carotid artery stenosis to determine whether a flow gap and poststenotic signal attenuation on 3 D-PC MRA were useful signs of severe carotid artery stenosis. Although nine patients with a flow gap alone had various degrees of stenosis ranging from 22.2 to 77.3 % without any decrease in regional cerebral blood flow (rCBF), 13 patients with both a flow gap and poststenotic signal attenuation had severe stenoses of 80 % or more, with a definite decrease in baseline rCBF. The presence of both a flow gap and poststenotic signal attenuation on 3 D-PC MRA appeared to be a reliable marker of severe carotid artery stenosis with a decrease in rCBF. Received: 30 April 1999/Accepted: 11 August 2000     

Pattern of atherosclerotic carotid stenosis in Korean patients with stroke: different involvement of intracranial versus extracranial vessels

BACKGROUND AND PURPOSE: The clinical pattern of stroke and the angiographic distribution of cerebral atherosclerosis in the Japanese and Chinese are different from those in whites. Our purpose was to evaluate the location and distribution of severe atherosclerotic stenoses in Korean patients by using cerebral angiography. METHODS: We retrospectively reviewed the cerebral angiographic findings in 268 patients (219 male, 49 female; mean age, 56 years) with one or more severe atherosclerotic stenoses (> or =70%), as shown on angiograms. These patients were selected from 1436 patients who were examined between 1996 and 1997. The analysis focused on the intracranial or extracranial location of the stenosis, the anterior and posterior circulations, and the multiplicity of the lesions. Statistical analysis was performed by using the chi(2) test. The data were then compared with data reported in other races and ethnic groups. RESULTS: A total of 389 severe stenotic sites were detected in 268 patients. A single stenosis was found in 56 (21%), and multiple stenoses were found in 212 (79%). Lesions were located in the intracranial area in 52% and in the extracranial area in 48%. They were detected in anterior circulation in 59% and in posterior circulation in 41%. Thirty-seven (66%) of 56 single stenosis were located in the intracranial area, and 19 (34%) were in the extracranial area. Of 333 lesions, 167 (50%) were multiple stenoses in the extracranial area, and 166 lesions (50%) were located in the intracranial vessels. The prevalence of intracranial stenosis was significantly higher in the single-stenosis group than in the multiple stenosis group (P <.05). CONCLUSION: Korean patients with severe atherosclerotic stenoses tend to have more intracranial stenoses. In particular, those with an isolated stenosis have more intracranial stenoses, compared with those with multiple stenoses.     

颈内动脉中重度狭窄支架置入血管成形术后局部脑灌注的变化及意义

目的 探讨颈内动脉支架置入血管成形术后脑血流动力学的变化情况.方法 对38例颈内动脉中重度狭窄患者行支架置入血管成形术,在手术前后对患者行脑CT灌注成像检查,观察患侧和对侧局部脑血流量(CBF)、脑血容量(CBV)及造影剂平均通过时间(MTT)的变化.结果 在支架置入血管成形术前,与对侧比较,患者患侧CBF、CBV降低...     

Combined use of color duplex ultrasonography and B-flow imaging for evaluation of patients with carotid artery stenosis

BACKGROUND AND PURPOSE: Color duplex ultrasonography (CDU) is a standard method of noninvasive evaluation of internal carotid artery stenosis (ICAS). B-flow imaging (BFI), on the other hand, is a newer method. We investigated the accuracy of the two noninvasive tests--CDU and BFI--each separately and as a combination of the two tests by comparing with digital subtraction angiography as a reference standard. METHODS: We performed CDU, BFI, and digital subtraction angiography on 95 consecutive patients with ICAS. Separate and combined test results of CDU and BFI were compared with digital subtraction angiography results. RESULTS: For identifying 70% to 99% ICAS, as CDU criterion, the ratio of internal carotid artery to common carotid artery peak systolic velocity had the highest diagnostic accuracy (sensitivity, 94%; specificity, 96%). The sensitivity and specificity of BFI were 65% and 98%, respectively. With CDU and BFI, results were concordant in 144 (89%) cases for 70% to 99% ICAS. Sensitivity and specificity of combined CDU and BFI results for identification of ICAS were 95% and 99%, respectively. The misclassification rates of CDU and BFI were 4.7% and 8.1%, respectively. When combined test results were concordant, the misclassification rate decreased to 1.4%. CONCLUSION: CDU showed a slightly better accuracy than did BFI in the diagnosis of carotid artery stenosis. Combined use of CDU and BFI is more accurate than use of either test alone.     

症状性颅外颈动脉狭窄的血管内支架和药物治疗的临床疗效研究

目的　对比分析症状性颅外颈动脉狭窄的血管内支架和单纯药物治疗的疗效 ,评价两种治疗方法的有效性和安全性。方法　 2 0 0 1年到 2 0 0 3年我科门诊及病房治疗的症状性颅外颈动脉狭窄2 6 5例 ,其中支架治疗组 16 0例 ,单纯药物治疗组 10 5例。结果　颈动脉支架成形术 (CAS)手术的技术成功率 10 0 % ,血管狭窄由术前平均 79.5 %± 14 .6 %降至术后平均 11.2 %± 7.8% (P <0 .0 1) ,血管直径由术前 1.5± 0 .6mm恢复至 4 .1± 0 .4mm。治疗 30d内支架组和药物组各有 1例大卒中 (0 .6 3%、0 .95 % ,P >0 .0 5 ) ,药物组死亡 1例 (0 .95 % ) ,支架组无死亡。平均随访 13.5个月 ,支架组无死亡 ,同侧卒中 1例(0 .6 3% ) ,总的卒中和死亡 2例 (1.2 5 % ) ,药物组同侧卒中 4例 (3.81% ) ,死亡 1例 (0 .95 % ) ,总的卒中和死亡 5例 (4 .76 % )。支架组再狭窄 1例 (0 .6 3% ) ,因患者临床没有脑缺血症状 ,未进行再次治疗。结论　颈动脉支架成形术是治疗症状性颅外颈动脉狭窄和预防卒中安全而有效的方法 ,其围手术期总的卒中和死亡率低 ,1年随访卒中复发率和再狭窄率低 ,较单纯药物疗效更好。     

Diagnostic accuracy of colour Doppler ultrasonography, CT angiography and blood-pool-enhanced MR angiography in assessing carotid stenosis: a comparative study with DSA in 170 patients

Purpose

This study was undertaken to prospectively evaluate the diagnostic performance of colour Doppler ultrasonography (CDUS), first-pass (FP) and steady-state (SS) contrast-enhanced magnetic resonance angiography (MRA) and computed tomography angiography (CTA) of the carotid arteries using digital subtraction angiography (DSA) as the reference standard.

Materials and methods

A total of 170 patients with previous cerebrovascular events and suspected carotid artery stenoses underwent CDUS, blood-pool MRA, CTA and DSA. Accuracy, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated for CDUS, FP MRA, SS MRA and CTA. The McNemar and Wilcoxon tests and receiver operating characteristic (ROC) curve analysis were used to determine significant differences (p<0.05) between the diagnostic performances of the four modalities, and the degree of stenosis was compared using linear regression.

Results

A total of 336 carotid bifurcations were studied. The area under the curve (AUC) for degree of stenosis was: CDUS 0.85±0.02, FP MRA 0.982±0.005, SS MRA 0.994±0.002 and CTA 0.997±0.001. AUC analysis showed no statistically significant difference between CTA and MRA (p=0.0174) and a statistically significant difference between CDUS and the other techniques (p<0.001). Plaque morphology analysis showed no significant difference between CTA and SS MRA; a significant difference was seen between CTA and SS MRA versus FP MRA (p=0.04) and CDUS (p=0.038). Plaque ulceration analysis showed a statistically significant difference between MRA and CTA (0.04< p<0.046) versus CDUS (p=0.019).

Conclusions

CTA is the most accurate technique for evaluating carotid stenoses, with a slightly better performance than MRA (97% vs. 95% for SS MRA and 92% for FP MRA) and a greater accuracy than CDUS (97% vs. 76%). Blood-pool contrast-enhanced SS sequences offer improved evaluation of degree of stenosis and plaque morphology with accuracy substantially identical to CTA.     

Recognizing subtle near-occlusion in carotid stenosis patients: a computed tomography angiographic study

Introduction

Near-occlusion of the internal carotid artery (ICA) is a significant luminal diameter (LD) reduction beyond a tight atherosclerotic carotid stenosis (CS). Recognition of even subtle near-occlusions is essential to prevent underestimation of the stenosis degree. Our goal was to investigate the prevalence of near-occlusion among CS patients using a single standard criterion to facilitate its recognition, even when distal ICA LD reduction is not visually evident in computed tomography angiography (CTA).

Methods

We analysed carotid artery CTAs of 467 patients with moderate-to-severe CS scheduled for endarterectomy. We performed measurements of the bilateral distal ICA LDs from thin axial source images and utilized a 1.0 mm intra-individual side-to-side distal ICA LD difference to distinguish near-occlusions, based on a previous study, aware of the vagaries of measurement. For analysis stratification, we excluded cases with significant carotid pathology affecting LD measurements.

Results

We discovered 126 near-occlusions fulfilling our criterion of ipsilateral near-occlusion: the mean LD side-to-side difference (mm) with 95% confidence interval being 1.8 (1.6, 1.9) and a standard deviation of 0.8 mm. Among the 233 cases not meeting our near-occlusion criterion, we found 140 moderate (50–69%) and 93 severe (70–99%) ipsilateral stenoses.

Conclusion

The utilization of 1.0 mm cut-off value for the intra-individual distal ICA LD side-to-side difference to distinguish atherosclerotic ICA near-occlusion leads to a relatively high incidence of near-occlusion. In CTA, recently suggested to be used for near-occlusion diagnosis, a discriminatory 1.0 mm cut-off value could function as a pragmatic tool to enhance the detection of even subtle near-occlusions.

     

Transoral ultrasonographic evaluation of carotid flow in predicting cerebral hemodynamics after carotid endarterectomy

PURPOSE: We investigated whether measurement of blood flow in the extracranial distal internal carotid artery (ICA) by transoral carotid ultrasonography (TOCU) can predict the cerebral hemodynamics and the hemodynamic effect of carotid endarterectomy (CEA) in patients with unilateral carotid stenosis. METHODS: Forty-nine patients with unilateral ICA stenosis who underwent CEA were studied. Preoperative blood flow in the poststenotic portion of the extracranial ICA was studied by using TOCU. Regional cerebral blood flow (rCBF) and vasoreactivity to acetazolamide (VR) in the territory of the middle cerebral artery were investigated by using single-photon emission CT (SPECT) before, 2 weeks after, and 3 months after CEA. RESULTS: Doppler flow velocities in the extracranial distal ICA measured transorally by TOCU correlated with baseline as well as postacetazolamide rCBF in the ipsilateral side (regression analysis, P < .05). Diameter and blood flow volume in the extracranial distal ICA were associated with ipsilateral postacetazolamide rCBF and VR (regression analysis, P < .05). When the patients were divided into 2 groups according to the ICA volume flow distal to a carotid stenosis, group I < 3.5 mL/s and group II > 3.5 mL/s, ipsilateral postacetazolamide rCBF in group I was significantly lower than that in group II (P = .008). Ipsilateral postacetazolamide rCBF (analysis of variance [ANOVA], P = .02) and VR (ANOVA, P = .03) significantly improved after CEA for 3 months in group I but not in group II. CONCLUSION: TOCU can detect the decrease in poststenotic flow of the distal extracranial ICA that is indicative of impaired intracranial hemodynamics and predictive for improvement of cerebral blood flow after CEA in patients with unilateral carotid stenosis.     

颈动脉内膜剥脱术治疗颈动脉粥样硬化狭窄的临床研究

目的探讨颈动脉内膜剥脱术（carotid endarterectomy,CEA）的适应证及围手术期处理。方法回顾性总结2001年2月—2011年2月在我科治疗的98例因颈动脉硬化狭窄（狭窄＞50%）而行CEA治疗的患者资料;其中,有症状77例（786%）,无症状21例（214%）。结果术后除2例（20%）死亡、3例（30%）发生一过性偏瘫和7例（71%）出现脑高灌注综合征外,其他患者疗效良好,未出现短暂脑缺血（transient ischemic attack,TIA）表现。术后随访1~10年,平均56年;随访76例,13例（17.1%）再狭窄＞70%,9例（118%）再发TIA症状,4例（53%）出现脑梗死。结论对于临床检查发现一侧或双侧颈动脉狭窄＞50%,特别是有TIA发作史的患者,可以考虑行CEA;双侧颈动脉狭窄者应分期手术治疗;做好围手术期处理,有助于减少手术并发症发生。     

影响颈动脉狭窄患者认知功能的因素调查

 目的 调查影响颈动脉狭窄患者认知功能的因素,为早期识别认知功能损害提供参考。方法 选择经全脑血管数字减影血管造影(DSA)技术诊断的颈动脉狭窄患者116例,通过蒙特利尔认知评估量表(MoCA)评估其认知功能,利用多重线性回归分析筛选认知功能的影响因素。结果 MoCA总分平均为19.23±2.52,检出认知功能损害患者72例,检出率为62.1%;多元线性回归分析结果显示年龄(β=-3.71,P=0.02)、吸烟(β=-2.02,P=0.02)、高血压(β=-2.40,P=0.02)、高血脂(β=-2.65,P=0.02)、糖尿病(β=-3.29,P=0.03)、狭窄程度(β=-4.41,P=0.03)等为颈动脉狭窄患者认知功能的影响因素。结论 颈动脉狭窄患者认知功能的影响因素可能包括血管性危险因素及狭窄本身的病理特征因素。     

颈动脉狭窄或闭塞患者数字记忆的功能磁共振成像研究

目的:探讨左侧颈内动脉/大脑中动脉狭窄和闭塞患者与正常人数字工作记忆的激活脑区差异及其记忆障碍的脑加工机制。方法:对12例左侧颈动脉狭窄/闭塞患者(其中左侧颈内动脉狭窄4例,左侧颈内动脉闭塞2例,左侧大脑中动脉狭窄5例,左侧大脑中动脉闭塞1例,24例正常对照组进行数字记忆任务的功能磁共振成像,采用AFNI软件进行数据分析和脑功能区活动图像。结果:左侧颈内动脉/大脑中动脉狭窄和闭塞患者的反应时间较对照组显著延长(P0.05),正确率较对照组明显降低(P0.05)。脑激活图显示数字工作记忆的编码期、保持期、提取期患者组的脑激活明显少于正常对照组,而且脑激活的左侧半球优势减弱,右侧半球出现代偿性激活,其中提取期最为明显。结论:左侧颈动脉狭窄/闭塞患者数字记忆任务的脑激活区存在损害,功能磁共振成像研究能为早期诊断认知障碍提供影像学依据。