Carotid artery dissection

Opinion statement  Dissection of the carotid artery in the neck is a relatively common condition. Most dissections are spontaneous, likely related to activities that cause sudden stretch of the pharyngeal portion of the carotid artery. Many patients do not develop brain ischemia but have a triad of neck and head pain, Horner’s syndrome, and pulsatile tinnitus. Others present with transient or persistent brain ischemia. Strokes are due to the embolization of thrombus material from the lumen of the dissected artery to the intracranial arteries, most often the middle cerebral artery. Although there have been no randomized therapeutic trials in patients with carotid artery dissection, experience shows that standard anticoagulants in the form of heparin followed by Coumadin (Du Pont Pharma, Wilmington, DE) are effective in preventing further artery-to-artery emboli.     

When and how to study the carotid arteries

STUDY OBJECTIVE: To appraise critically the clinical indications for diagnostic evaluation of carotid artery disease and the efficacy, safety, limitations, and relative costs of commonly used noninvasive diagnostic tests. DESIGN: Formal decision analysis to determine the relative value of several diagnostic strategies and information synthesis of studies evaluating noninvasive diagnostic tests. SETTING: We did a secondary analysis of the literature, using available data to generate estimates for the probability of selected, clinically important events and the utilities of relevant outcomes observed in patients when carotid artery disease is present or absent, and we critically appraised studies reported since 1980 to estimate the sensitivity and specificity, safety, limitations, and costs of diagnostic tests. MAIN RESULTS: For patients with asymptomatic neck bruits who are and who are not being considered as candidates for other vascular surgery, no diagnostic testing is recommended. For symptomatic patients with anterior-circulation transient ischemic attacks or previous minor strokes, noninvasive diagnostic testing is recommended if surgical treatment is being considered. Patients who previously had minor strokes could be directly referred for selective carotid angiography because they have a higher likelihood of a surgically approachable carotid lesion. Patients with nonlateralizing signs and symptoms of ischemia do not need diagnostic evaluation of possible carotid artery disease unless their symptoms are related to ischemia in the carotid artery circulation. The preferred noninvasive diagnostic test is duplex ultrasound, which has a sensitivity of approximately 85% and a specificity of 90%. If duplex ultrasound is not available, an alternative noninvasive test is carotid Doppler ultrasound. CONCLUSIONS: We recommend a conservative diagnostic approach in patients with suspected carotid artery disease. Noninvasive diagnostic testing is indicated only for symptomatic patients with transient ischemic attacks in the anterior circulation who are considered candidates for carotid endarterectomy, when knowledge of the vessel anatomy is necessary.     

30例颈动脉内膜剥脱术的临床总结

目的:对颈动脉内膜剥脱术预防和治疗缺血性脑卒中的临床疗效进行评价,并提出主要外科技术及手术指征。方法:2009年1月至2012年1月收治的患者30例,且根据所有患者的临床表现以及颈部血管多普勒超声、数字减影(DSA)、CT血管造影(CTA)等检查可确诊为脑卒中。对所有患者行颈动脉内膜剥脱术(carotid endarterectomy,CEA),绝大多数病例均采用全麻,几乎所有病例均采用转流管维持脑部供血,剥离颈动脉斑块。结果:随访6～24个月,30例患者术后恢复良好,脑缺血症状有明显改善,所有患者围手术期内均未出现死亡及脑卒中事件,并且在术后1年的随访中均未出现脑卒中,未出现严重并发症,且患者的生活质量有明显改善。结论:颈动脉内膜剥脱术对预防和治疗缺血性脑卒中是安全有效的。     

Feasibility and safety of transradial artery approach for selective cerebral angiography.

The transradial artery (TRA) approach is a conventional means of diagnostic cardiac catheterization and catheter-based coronary intervention. However, to our knowledge, the safety and feasibility of cerebrovascular angiographic studies using the TRA approach for patients with brain ischemia has not been reported. This study investigated whether the TRA approach using 6 Fr Kimny guiding catheter for both extracranial and intracranial angiographies is safe and effective for patients with a history of stroke, transient ischemic attack, or significant carotid stenosis. From February 2003 to June 2004, a total of 46 consecutive patients with an age range from 50 to 83 years were enrolled into the study. The retrograde engagement technique that involved lopping the guiding catheter was utilized. Outpatient carotid angiography was performed in 40% of the study patients. The overall procedural success (defined as completely evaluating both carotid and vertebral arteries and intracranial vessels) was 93.5% (n = 43) using the Kimny guiding catheter. Significant cerebrovascular stenosis (> 50%), including carotid artery in 52.2% (n = 24), vertebral artery in 15.2% (n = 7), and intracranial major artery in 15.2% (n = 7), was found in 82.6% of the patients. Notably, 17 (37.0%) of these patients with severe carotid stenosis (> or = 70%) required staged carotid stenting. Concomitant vertebral artery stenting was performed in four (8.7%) patients because of severe stenosis (> or = 70%) of these vessels. Two patients experienced transient dizziness (duration < 30 min) following the procedure. TRA approach for selective cerebral angiography is safe and feasible in patients with a history of brain ischemia.     

Spontaneous Dissection of Internal Carotid Artery Masquerading as Angioedema

Spontaneous dissection of the internal carotid artery usually presents with stroke-like symptoms secondary to ischemia in its vascular territory, as well as local signs and symptoms, which may include head, face or neck pain, Horner’s syndrome, pulsatile tinnitus, and cranial nerve palsies. We report a case of a 44-year-old healthy white male who presented with tongue swelling mimicking angioedema as an unusual manifestation of spontaneous dissection of the internal carotid artery. Two weeks after the initial presentation, the patient returned with similar symptoms and slurred speech. Upon physical examination, he was noted to have isolated left-sided hypoglossal nerve palsy. Subsequent diagnostic imaging revealed segmental narrowing of the left internal carotid artery. The appearance was consistent with the presence of a spontaneous internal carotid artery dissection with associated pseudoaneurysm formation.     

介入可控性兔颈动脉狭窄导致早期脑缺血动物模型的建立

目的建立能直接观察到颈动脉狭窄对全脑缺血、缺氧的可控性全脑缺血兔实验模型；此模型可进一步开展顼动脉狭窄导致老年脑缺血后相应的形态学、机能代谢学、药物学、临床治疗学等方面的研究。方法通过介入手段。把自制圆柱中空模型输送到兔颈动脉以达到颈动脉理想的狭窄程度，再通过1．5T MRI弥散成像证实颈动脉狭窄后脑缺血的存在。结果能直接观察不同颈动脉狭窄程度对全脑缺血的影响程度。结论本横型克服了以往脑缺血模型建立均为选择性全血管栓塞或血管外致闭塞，耐受缺血时间短。不能直接观察到脑缺血各种状态下的反应，不便于开展药物学、临床治疗学方面的研究等不足，为更深入广泛地进行颈动脉狭窄导致老年脑缺血方面的研究打下了基础。     

Noninvasive evaluation of the extracranial carotid arteries in patients with cerebrovascular events and atrial fibrillations

Noninvasive carotid artery testing was performed in 73 patients with nonvalvular atrial fibrillation who were referred because of symptoms or signs of cerebrovascular disease. Thromboembolism related to atrial fibrillation without valvular heart disease was the probable source of cerebral ischemia in 25 (80%) of 31 patients with stroke and coexisting atherosclerotic disease at the carotid artery bifurcation in six (20%). Nonvalvular atrial fibrillation was the probable source of symptoms in nine (70%) of 13 of patients with transient cerebral ischemia, while coexisting carotid artery disease was present in four (30%). Nonvalvular atrial fibrillation accounted for the symptoms in four of five patients with amaurosis fugax, with atherosclerotic carotid artery disease present in one. The remaining 24 patients had nonhemispheric symptoms of cerebrovascular disease, including vertebrobasilar insufficiency, dizziness, and syncope, and only one had a carotid lesion. A significantly higher proportion of patients with focal hemispheric symptoms had coexisting carotid disease than patients with nonfocal symptoms had, suggesting that atherosclerotic cerebrovascular disease contributes to stroke in patients with nonvalvular atrial fibrillation. Noninvasive carotid artery testing may be helpful in identifying atherosclerotic lesions at the carotid artery bifurcation in patients with atrial fibrillation and cerebrovascular disease, because different therapeutic modalities may be appropriate when two potential sources of cerebral ischemia are present.     

Magnetic resonance angiography in coronary artery bypass grafting

An attempt was made to reduce the incidence of perioperative stroke by detecting cerebrovascular disease with preoperative head and neck magnetic resonance angiography and by selecting the coronary artery bypass grafting technique. This strategy was used in 268 patients with ischemic heart disease who had undergone both head and neck magnetic resonance angiography before elective coronary artery bypass in our hospital between May 1997 and April 2001. In patients with significant stenosis or obstruction detected by head and neck magnetic resonance angiography, the findings were evaluated and cerebral blood flow was examined using brain single-photon emission computed tomography. In those with a high risk of cerebrovascular ischemia, off-pump coronary artery bypass was performed to maintain cerebral blood flow. No stroke occurred during surgery, and hemodynamic cerebrovascular ischemia was prevented in all 268 patients. Postoperative stroke occurred in 3 patients (1.1%), but the incidence of perioperative stroke was reduced.     

Special cerebral perfusion in surgery for the ruptured thoracic aortic aneurysm.

BACKGROUND: For surgical treatment of the ruptured thoracic aortic aneurysm (TAA), it is important to control bleeding and to protect the brain, spinal cord, and myocardium. We have developed and performed a new procedure on 6 patients with a ruptured TAA, a true aneurysm in 3 patients and a type A dissection in the other 3. METHOD: Cardiopulmonary bypass is installed with cannulations to the iliac artery and vein and to the common carotid arteries on both sides of the neck before the sternum is divided. For control of bleeding, venous drainage is accelerated, whereas cerebral perfusion is maintained via the carotid arteries. After insertion of the occlusion catheters into the descending aorta and the left subclavian artery following the aortotomy, the bypass flow to the iliac artery is increased. RESULTS: The arch replacement was performed in 4 patients and hemiarch replacement in two. Five patients are alive without neurologic deficits; one patient died of multi-organ failure on the 24th postoperative day. CONCLUSIONS: We conclude that our procedure may be advantageous for patients with a ruptured TAA, a large retrosternal aneurysm, or reoperation of the thoracic aorta.     

Unilateral and Bilateral Vertebral Artery Dissection Following Motor Vehicle Injury—Two Cases and a Mini-Review

Vertebral artery dissection in two patients with traumatic brain and cervical spine injury was treated in the intensive care unit. In both cases vertebral artery dissection was suspected solely by the presence of ischemic lesions on the cervical spine and by magnetic resonance imaging of the brain, performed because of a failure to recover consciousness. In the intensive care unit patients with head and neck trauma, symptoms of posterior circulation ischemia due to traumatic vertebral artery dissection, often overlap with those with traumatic brain injury. A high level of suspicion for vertebral artery dissection has to be maintained in order to prompt further investigation in to these cases.     

Hemodynamic characteristic of the common carotid arteries in diabetic atherosclerotic patients

Early detection of stenosis is an important task in noninvasive examinations. The authors analyzed 50 patients with diabetic macroangiopathy in lower limbs, but without signs, or symptoms of brain ischemia, and 50 supposedly healthy subjects of similar sex and age composition as control. Eight hemodynamic parameters were measured in the common carotid artery using Doppler ultrasound with spectral analysis. Only 6% of the control group, but 64% of the diabetic patients had two or more altered parameters. The authors conclude that persons with high risk of cerebrovascular disease could be identified by Doppler ultrasound examination of common carotid artery.     

Focal ischemia of the brain after neuroprotected carotid artery stenting

OBJECTIVES: This study sought to assess the incidence of cerebral ischemia in nonselected patients undergoing neuroprotected carotid angioplasty and stenting (CAS) without preceding multiple-vessel diagnostic angiography. BACKGROUND: Protection devices to prevent distal embolization during CAS are presently under clinical investigation. Diffusion-weighted magnetic resonance imaging (MRI) visualizes recent ischemia of the brain and may aid in assessing the efficacy of protection devices. METHODS: Elective CAS was performed in 42 consecutive patients (15 female, 27 male; mean age, 67 +/- 9 years) using six different types of cerebral protection systems. All patients underwent MRI of the brain before and after a total of 44 interventions. RESULTS: Placement and retrieval of the devices and stent deployment was achieved in all procedures. New ischemic foci were seen on postinterventional MRI in 10 cases (22.7%). One patient had sustained a major stroke, whereas no adverse neurological sequelae were associated with the other nine procedures. In the latter, one to three foci (maximum area 43.0 mm(2)) were detected in cerebral regions subtended by the ipsilateral carotid artery in eight cases and by the contralateral carotid artery in one case. In the stroke patient, 12 ischemic foci (maximum area 84.5 mm(2)) were exclusively located in the contralateral hemisphere. Follow-up MRI at 4.1 months (median, n = 7) identified residuals of cerebral ischemia only in this patient. CONCLUSIONS: Neuroprotected CAS is associated in about 25% of cases with predominantly silent cerebral ischemia. Our findings suggest manipulation of endoluminal equipment in the supraaortic vessels to be a major risk factor for cerebral embolism during neuroprotected CAS.     

缺血性脑血管病患者颈内动脉斑块的形态学研究

目的　探讨缺血性脑血管病患者和对照组颈内动脉斑块的形态学差异。方法　对 8例有缺血性脑血管病症状的死者进行尸体解剖 ,并对其颈内动脉进行连续取材 ,光镜观察斑块形态 ,并通过图像分析系统对斑块内脂质大小、斑块纤维帽厚度进行测定。同时对 8例年龄相当的无缺血性脑血管病症状的死亡病例 ,做颈内动脉对照研究。选取部分稳定及不稳定斑块进行免疫组织化学染色 ,观察二者巨噬细胞含量的差异。结果　 8例缺血性脑血管病组共 12 1个颈内动脉取材块中 ,不稳定斑块占 2 1.5 % (2 6 12 1) ;而对照组 10 9个颈内动脉取材块中不稳定斑块仅占11.0 % (12 10 9)。差异有显著性意义 (P <0 .0 1)。纤维帽厚度在有症状组和无症状组分别为 (0 .3± 0 .2 )mm和(0 .5± 0 .3)mm ,差异有显著性意义 (P <0 .0 1)。免疫组织化学显示不稳定斑块中巨噬细胞数量明显多于稳定斑块。结论　缺血性脑血管病患者颈内动脉斑块破裂与血栓形成的机会增加 ,斑块脂质中心越大 ,斑块表面纤维帽越薄 ,巨噬细胞越多 ,则斑块越不稳定 ,越容易破裂导致缺血性脑血管病症状的发生。     

6例颈内动脉盗血综合征的临床分析

目的 探讨颈内动脉盗血综合征的临床特点.方法 分析6例颈内动脉盗血综合征患者的临床表现、CT或MRI、数字减影血管造影及血流代偿情况.结果 6例患者中,单侧颈内动脉闭塞2例,严重狭窄4例(其中左侧2例,右侧1例,双侧1例).颈内动脉盗血综合征患者临床表现为分水岭区脑梗死和短暂性脑缺血发作,后循环缺血4例,前循环缺血2例.数字减影血管造影提示,6例患者均有侧支循环建立,前交通动脉、后交通动脉和软膜动脉是常见的代偿血管.结论 颈内动脉盗血综合征可表现为前、后循环缺血症状,侧支循环在代偿中起重要作用.

Abstract：

Objective To investigate the clinical features of internal carotid steal syndrome. Methods The clinical manifestations, CT or MRI, digital subtraction angiography, and blood flow compensation in 6 patients with internal carotid steal syndrome were analyzed. Results Of the 6 patients, 2 had unilateral internal carotid artery stenosis, 4 had severe stenosis (in which 2 were on the left side, 1 was on the right side, and 1 was on both sides). The clinical manifestations of the patients with internal carotid steal syndrome were watershed infarction and transient ischemic attack. Four patients had posterior circulation ischemia and 2 had anterior circulation ischemia. Digital subtraction angiography demonstrated that collateral circulation was established in all the 6 patients. The anterior communicating artery, posterior communicating artery, and pial artery were the common compensatory vessels. Conclusions Internal carotid artery steal syndrome can be presented as anterior or posterior circulation ischemia, and the collateral circulation plays an important role in the compensation.     

颈部大动脉粥样硬化与短暂性脑缺血发作的相关研究

目的　评价颈部大动脉粥样硬化与短暂性脑缺血发作 (TIA)的相关性。方法　对 16 8例TIA患者进行颈部大动脉彩色多普勒检测 ,同期来院健康体检者 6 0例为对照组。结果　TIA患者颈动脉内膜中层厚度 (IMT)和斑块的发生率较对照组明显增加 ,两组比较差异有显著性意义 (P <0 .0 1)。椎 基底动脉系统TIA患者锁骨下动脉起始处的斑块发生率明显多于颈内动脉系统TIA患者 ,差异有显著性意义 (P <0 .0 1)。TIA患者颈内动脉的IMT值与血浆总胆固醇、甘油三酯、纤维蛋白原的含量成正相关 (P <0 .0 1)。结论　彩色多普勒超声可作为颈部大动脉粥样硬化检测的可靠方法。颈部大动脉粥样硬化的形成与TIA的发病密切相关     

6例颈内动脉盗血综合征的临床分析

目的 探讨颈内动脉盗血综合征的临床特点.方法 分析6例颈内动脉盗血综合征患者的临床表现、CT或MRI、数字减影血管造影及血流代偿情况.结果 6例患者中,单侧颈内动脉闭塞2例,严重狭窄4例(其中左侧2例,右侧1例,双侧1例).颈内动脉盗血综合征患者临床表现为分水岭区脑梗死和短暂性脑缺血发作,后循环缺血4例,前循环缺血2例.数字减影血管造影提示,6例患者均有侧支循环建立,前交通动脉、后交通动脉和软膜动脉是常见的代偿血管.结论 颈内动脉盗血综合征可表现为前、后循环缺血症状,侧支循环在代偿中起重要作用.     

颈动脉狭窄支架置入术后眼部并发症的临床分析

目的分析动脉内支架置入治疗过程中的眼部并发症,为减少严重的视力丧失提供指导方法收集412例住院行颈动脉内支架置入治疗的颈动脉狭窄患者的临床资料,分析其眼部并发症。结果 412例患者中有3例患者发生眼部并发症,其中发生眼缺血综合征1例,缺血性视神经病变1例,视网膜分支动脉栓塞1例,发生率为0.7%。结论颈动脉内支架置入治疗时需要注意颈动脉狭窄相关眼部并发症,详细的病史采集和眼部检查以及在治疗前和治疗过程中,明确眼动脉的起源或代偿供血血管非常重要。     

The brain scan and cervical artery lesions. Correlations: clinical-arteriographic-scanning

Cerebral angiography and CT brain scan are performed on a group of 174 patients (28 asymptomatic patients; 109 patients with symptoms of stroke in relation with a clinically defined vascular territory; 37 patients with symptoms in relation with a clinically uncertain vascular territory). Angiographic findings are: cervical artery lesions in 143 patients, brain artery lesions in 6 patients, both extra and intra cranial artery lesions in 22 patients, and non atheromatous artery lesions in 3 patients. CT brain scan shows: hypodensity in 19 cases, hyperdensity in 1 case, cortical and/or sub cortical atrophy in 141 cases. Only 13 patients have normal CT brain scan. Authors also note: 4 infarction areas in asymptomatic patients and only 4 hypodensities out of 21 cases of internal carotid artery occlusion. Ulcerated cervical artery lesions seem to be the main cause (73%) of cerebral infarction.     

Rapid Noninvasive Continuous Monitoring of Oxygenation in Cerebral Ischemia and Hypoxia

The brain is most sensitively dependent on oxygen to maintain its normal function. Methods to assess the degree of its oxygenation have generally been invasive and indirect. Rapid assessment of brain oxygenation is particularly vital during cerebrospinal ischemia and hypoxia. We have developed a noninvasive electro-optical method using pulsed near-infrared (NIR) light to quantify brain oxygenation during ischemia and hypoxia in anesthetized rabbits. Cerebral ischemia was induced through 30–40 s of bi-lateral carotid artery occlusion. Cerebral hypoxia was induced by varying inspired oxygen levels. The NIR light response to the interventions was expressed in terms of relative absorption (RA). Results showed that our pulsed NIR system could rapidly detect sudden alterations in oxygenation and blood flow to the brain. The response patterns during cerebral ischemia and hypoxia were significantly different, although both decreased brain oxygenation. The overall RA response to ischemia was much faster (in seconds) than during hypoxia (in minutes). These different response patterns can serve as early warning signal of low brain oxygenation and to discriminate the cause of the diminished oxygenation. The present pulsed NIR system is capable to provide a rapid, noninvasive and continuous monitoring of such decreases in brain oxygenation.     

Endovascular treatment of carotid artery aneurysms with stent grafts

Two patients with cervical carotid artery aneurysms were treated with stent grafts. Case report #1 was a 65-year-old male with aneurysm of the right internal carotid artery and recurrent transient ischemic attacks. Case report #2 describes a 64-year-old male with a pulsatile neck mass and persistent neck discomfort. Both patients underwent successful implantation of stent grafts with complete obliteration of the aneurysms and alleviation of symptoms. Case report #2 also underwent coil embolization of the right external carotid artery to prevent retrograde filling of the aneurysmal sac. Endovascular stent graft obliteration of carotid aneurysms appears safe, feasible and a less invasive option compared to surgical repair.