Hemodynamic significance of internal carotid artery disease

Neurologic symptoms in the region of an internal carotid artery stenosis are considered to be embolic in most instances. Only in a subgroup has carotid occlusive disease with impairment of the collateral supply, caused a state of hemodynamic failure with marked reduction of perfusion pressure. Though unproven, it is reasonable to assume that without surgical intervention, the risk is higher than average for patients with hemodynamic failure. Equally, should there be any postoperative improvement of cerebral blood flow or neurologic deficits, it should be looked for in this group. Thus, it is necessary to distinguish those with low perfusion pressure from the population of patients with carotid artery disease. Preoperative clinical evaluation and direct visualization of the carotid bifurcation should be supplemented by indirect physiological tests which allow assessment of collateral perfusion. Examination of periorbital flow direction or oculoplethysmography could be used as a screening procedure. Negative tests most certainly rule out any severe pressure gradient across the stenosis, irrespective of the luminal reduction. A positive result, on the other hand, should be further quantified since most indirect tests become positive at relatively small pressure gradients. Studies of cerebral blood flow at rest and during cerebral vasodilation makes it possible to identify patients with severe reduction of cerebral perfusion pressure. Such hemodynamic failure of one hemisphere may be identified in most cases by a conventional non-invasive xenon-133 technique and stationary detectors. Smaller focal regions of hypoperfusion may be identified by computer emission tomography, either by the detection of single-photon emission or by paired detection of annihilation photons. Endarterectomy does improve cerebral hemodynamics in terms of increased flow through the reconstructed vessel and elimination of pressure gradients. The cerebral blood flow, though remains unchanged in the majority of patients, at least when measured at baseline. Only in those patients with a reduction in perfusion pressure can a significant improvement in baseline flow occur. Flow reserve determined by cerebral vasodilation, however, will improve in most patients with hemodynamic failure. In addition, some patients in the low-pressure group develop marked, but temporary, hyperperfusion after reconstruction of very high grade carotid stenosis. This is considered a result of chronic low perfusion pressure with subsequent loss of autoregulation, and autoregulatory control is first regained after some days.(ABSTRACT TRUNCATED AT 400 WORDS)     

Facial nerve palsy secondary to internal carotid artery dissection

We report facial palsy as the sole cranial neuropathy complicating an ipsilateral internal carotid artery dissection. A previously healthy 44-year-old man developed retro-orbital and temporal headache with associated nausea while engaged in modest physical exercise. On the following morning he noticed a left ptosis and miotic pupil. One week later he woke with a left facial weakness. On the same day he had a 90-minute episode of expressive dysphasia. Magnetic resonance imaging and angiography demonstrated left internal carotid artery dissection. The temporal association between our patient's facial nerve palsy and typical features of spontaneous internal carotid artery dissection suggests a common aetiology. We suggest that involvement of the VII cranial nerve in isolation followed disruption of an anomalous nutrient artery. The delay in clinical manifestation may imply extension of the dissection.     

The role of vertebral and internal carotid artery disease in the pathogenesis of vertebrobasilar transient ischemic attacks

Summary Color-coded duplex sonography has improved the evaluation of the hemodynamics of the vertebral arteries (VA). A reliable differentiation between a normal vessel, hypoplasia, stenosis and occlusion of VA can now be made. We studied two groups of patients in a prospective study with isolated carotid artery disease (n=48), and with a combination of carotid and vertebral artery disease (n=14), to determine the role of VA in the pathogenesis of transient ischemic attacks (TIAs) in the vertebrobasilar system. Apart from the existing arteriosclerotic changes of the internal carotid arteries, the condition of the VA was of importance for the occurrence of TIAs in the vertebrobasilar territory. We found that 8% of the patients with isolated hemodynamically relevant stenosis or occlusion of one or both internal carotid arteries had a TIA in the vertebrobasilar territory. Patients with combined carotid and vertebral artery disease had an increase of TIAs in the same region in 71%. The high rate of TIAs in this group might be attributed to the combined effect of carotid and vertebral artery disease, as a third group (n=30) with isolated vertebral artery disease showed TIAs in only 13%.     

Comparison between directional Doppler and angiography in the diagnosis of internal carotid artery disease

Directional Doppler examination (DD) with flow registration over the supraorbital and supratrochlear arteries and over the carotid artery in the neck was adopted to 99 carotid arteries in 56 patients without previous knowledge of angiography results, and thereafter DD and angiography findings were compared. On subgrouping of the angiography results into internal carotid artery (ICA) stenosis < 50 %, > 50 %, and occlusion, a correct diagnosis was obtained by DD on 90 vessels (91 %). All 11 ICA occlusions were correctly diagnosed by DD. The incorrect results obtained with DD were as follows: Four ICA stenosis < 50 % were classified as stenosis > 50 %; four stenosis > 50 % were classified as < 50 %; one stenosis > 50 % was classified as occlusion.
DD is a useful noninvasive screening method for the detection of occlusion and > 50 % stenosis of ICA.     

血管成形术治疗症状性重度颈动脉狭窄的临床研究

目的 探讨颈动脉内膜剥脱术(carotid endarterectomy,CEA)和颈动脉支架成形术(carotid artery stenting,CAS)治疗症状性重度颈动脉狭窄的近期和中期临床效果.方法 回顾性地分析了2016年1月至2018年12月在我院接受CEA或CAS治疗的203例症状性重度颈动脉狭窄患者的...     

A rare cause of transient ischemic attacks: Saccular aneurysm of the internal carotid artery

Summary Two patients are described with an unusual cause of transient ischemic attacks: saccular aneurysm of the extracranial part of the internal carotid artery. As both patients experienced amaurosis fugax, we assumed that emboli were being formed in the aneurysm. Both patients were treated with aspirin and suffered no further symptoms.

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Zusammenfassung Bei zwei Patienten wurde als ungewöhnliche Ursache von transienten ischämischen Attacken ein sackförmiges Aneurysma der extrakraniellen Portion der Carotis interna nachgewiesen. Da bei beiden Patienten eine Amaurosis fugax vorkam, nehmen wir an, daß aus einem Thrombus im Aneurysma Emboli entstanden war. Beide Patienten wurden mit Aspirin behandelt und hatten unter dieser Therapie keine weiteren Symptome.

     

颈内动脉狭窄相关性脑缺血病变的临床分析

目的 探讨颈内动脉狭窄致脑缺血病变的临床特点及发生机制,为临床指导治疗及判断预后提供依据.方法 回顾分析111 例经CT 血管造影(CTA)证实的颈内动脉狭窄患者的颅内Willis 环形态、TCD 资料及临床表现.结果 颈内动脉轻、中、重度狭窄组脑梗死发生率分别为14.7% 、30.6% 、46.3%,三组间差异具有显...     

颈内动脉系统TIA型脑梗死与高同型半胱氨酸血症关系的临床研究

目的 探讨血同型半胱氨酸水平与颈内动脉系统短暂性脑缺血发作(transient ischemic attack,TIA)及颈内动脉系统短暂性脑缺血发作(TIA型)脑梗死的关系.方法 对颈内动脉系统TIA及颈内动脉系统TIA型脑梗死的患者血同型半胱氨酸水平进行分析.结果 颈内动脉系统TIA型脑梗死患者血同型半胱氨酸水平高于颈内动脉系统TIA患者,且两组患者的血同型半胱氨酸水平水平均高于对照组.结论 高同型半胱氨酸血症与颈内动脉系统短暂性脑缺血发作相关,且其升高水平与是否进展为脑梗死有关.     

Chronic remote ischemic conditioning for symptomatic internal carotid or middle cerebral artery occlusion: A prospective cohort study

AimsRemote ischemic conditioning (RIC) has been demonstrated to reduce recurrent stroke in patients with intracranial artery stenosis. This study aimed to evaluate the effects of RIC in patients with the symptomatic internal carotid artery (ICA) or middle cerebral artery (MCA) occlusion.MethodsThis study is based on a high‐volume single‐center prospective cohort study in China, which included patients with symptomatic ICA or MCA occlusion with impaired hemodynamics and receiving chronic RIC. Clinical follow‐up visits were performed regularly, and cardio‐cerebrovascular events were assessed.ResultsIn total, 131 patients (68 with ICA occlusion and 63 with MCA occlusion; mean age, 52.6 ± 13.7 years; stroke, 73.5%; transient ischemic attack TIA, 26.5%) qualified for the analysis; the mean follow‐up period was 8.8 years (range, 3–14 years). The compliance of RIC was 95.6 ± 3.7%, and no associated severe adverse events happened. The annual risk of ischemic stroke and ischemic cerebrovascular events was 2.4% and 3.3%, respectively. The cumulative probabilities of ischemic cerebrovascular events and major adverse cardiovascular and cerebrovascular events were 32.8% and 44.8% at 14 years, respectively.ConclusionIn patients with symptomatic ICA or MCA occlusion with impaired hemodynamics, chronic RIC is well‐tolerated, and it appears to be associated with a low annual risk of ischemic stroke and cardio‐cerebrovascular events.     

DSA对单侧颈内动脉系统大动脉狭窄或闭塞后侧支循环建立的应用价值

目的 探讨DSA对单侧颈内动脉系统大动脉狭窄或闭塞后侧支循环建立的应用价值,探讨三级侧支循环在单侧颈内动脉开口部位狭窄或闭塞及大脑中动脉M1段狭窄或闭塞中的特点.方法 分别对56例颈内动脉开口处狭窄或闭塞及94例大脑中动脉M1段狭窄或闭塞的患者进行脑血管造影检查,根据其狭窄程度分析其侧支循环建立的情况.结果 颈内动脉开口部位闭塞组大脑动脉环开放率约38.5%,颅内外沟通开放率30.8%,软脑膜吻合支开放率约30.8%;重度狭窄组大脑动脉环开放率35.1%,软脑膜吻合支开放率16.2%,颅内外沟通开放率约5.4%;中轻度狭窄组无侧支循环建立.大脑中动脉M1段闭塞组大脑动脉环开放率5%,软脑膜吻合支开放率95%;重度狭窄组仅软脑膜吻合支开放,开放率约61%;轻中度狭窄组无侧支形成.结论 在颈内动脉开口部位重度狭窄或闭塞的病例中,一级侧支循环的开放代偿最为重要,二级侧支循环起着重要的辅助作用.在大脑中动脉M1段重度狭窄或闭塞的病例中,二级和三级侧支循环的开放起主要的代偿作用.     

颈内动脉扭曲的特点及其脑血流动力学变化

目的 研究颈内动脉(ICA)扭曲的特点及其脑血流动力学变化.方法 对223例缺血性脑血管病患者进行全脑血管造影和经颅多普勒超声检查.观察ICA扭曲的形态,将患者分为ICA扭曲组及正常组.比较两组的脑血流动力学参数.结果 全脑血管造影示ICA扭曲159例(ICA扭曲组),其中双侧扭曲127例(79.9％),单侧扭曲32例(20.1％);无扭曲64例(正常组).扭曲的类型以迂曲型最多(47.8％),折曲型次之(36.8％),盘曲型最少(5.3％);其中ICA左侧迂曲率(56.7％)显著高于右侧(43.3％)(P＜0.05).与正常组比较,ICA扭曲组及双侧折曲患者的大脑中动脉的收缩期峰速、舒张末期血流速度、平均血流速度、搏动指数及阻力指数明显降低(均P＜0.05);双侧迂曲患者各血流动力学参数的差异无统计学意义.结论 ICA扭曲以迂曲型和折曲型为主.ICA扭曲及其折曲型可引起脑血流动力明显降低,迂曲型则无显著改变.     

颈内动脉重度狭窄或闭塞患者的侧支循环与神经功能的单因素分析

目的 探讨颈内动脉重度狭窄或闭塞患者侧支循环的代偿作用与临床神经功能缺损程度的关系. 方法对52例连续颈内动脉狭窄或闭塞所致的脑梗死患者入院时行神经功能缺损评分(NIHSS)评分,利用数字减影脑血管造影技术(DSA)评估颅内动脉的侧支循环代偿情况.应用统计学方法探讨两者之间的关系.结果 DSA发现52例患者18例出现颈内动脉闭塞,单侧颈内动脉重度狭窄28例,6例双侧重度狭窄.52例患者中出现前交通动脉代偿18例,后交通动脉代偿8例,前后交通动脉同时代偿12例,14例患者未出现Willis环血管的代偿.无Willis环代偿组与Willis环代偿组NIHSS评分平均秩次分别为35.75和23.09,两组差异有统计学意义(P<0.05).前交通代偿组与后交通代偿组NIHSS评分平均秩次分别为12.42和15.94,两组差异无统计学意义(P<0.05).结论颈内动脉狭窄或闭塞时可通过多种方式进行有效的代偿.NIHSS评分与血管代偿及阻塞位置显著有关.DSA对侧支循环的判定在治疗干预中显得尤为重要.     

Pharyngo-occipital artery variant arising proximal to occluded internal carotid artery: The risk of an unnecessary endarterectomy

Collateral branches originating from the cervical internal carotid artery (ICA) are rare but can have significant clinical and surgical implications. We present a case of pharyngo-occipital artery arising proximal from an occluded ICA that was missed and confused for severe stenosis of the ICA, leading to the misguided indication for carotid endarterectomy. Advanced preoperative studies allowed timely recognition of this anomaly and reconsideration of the therapeutic plan. We stress the importance of recognizing these variants by careful examination of multimodal pre-surgical exams. Awareness of these variants will allow a more precise diagnosis, and more appropriate management of patients with carotid artery disease.     

颈内动脉分叉上间隙的显微外科解剖

目的 探讨颈内动脉分叉上间隙的解剖特征及其手术意义。方法 在30侧尸体标本上观察该间隙的显微解剖。结果 该间隙狭小、深在，血管多，90％呈三角形、A1段为前下边，M1段为外下边，前穿质为上边。10％呈四边形，视交叉或视束构成其内侧边。间隙内常有Heubner回返动脉和大脑中深静脉等走行，经间隙可见下方的诸多小血管。结论 在至少1／3的间隙内容易展开显微操作，多数需慎重处理间隙内的小血管。     

颅外段颈内动脉夹层的治疗

目的 探讨颅外段颈内动脉夹层（eICAD）抗血小板药物治疗及血管内治疗的疗效。方法 2013年6月至2014年12月收治4例eICAD患者,采用抗血小板药物（阿司匹林100mg/d+氯吡格雷75mg/d）治疗或血管内支架治疗。结果 出院后随访6个月,1例在药物治疗2周后出现新发脑缺血事件,给予血管内支架成形术治疗后无再发脑缺血事件;其余3例随访期内未出现新发脑缺血事件。1例血管闭塞的患者,经双抗治疗后,血管再通;2例血管重度狭窄的患者,经双抗治疗后,血管狭窄明显减轻;1例药物治疗无效后血管内支架治疗患者,血管恢复通畅,无残余狭窄。发生脑卒中的3例患者,改良Rankin评分均不同程度的改善。结论 对eICAD的治疗,可以选择在阿司匹林联合氯吡格雷抗血小板治疗的基础上,严密观察患者病情,对有新发脑缺血事件的病例,采用血管内支架成形术治疗,可以取得良好的疗效。     

Effects of uncomplicated carotid endarterectomy on cognitive function and brain perfusion in patients with unilateral asymptomatic severe stenosis of the internal carotid artery by comparison with unoperated patients

Objective: The purpose of the present exploratory study was to evaluate the effects of uncomplicated carotid endarterectomy (CEA) on cognitive function and brain perfusion in patients with unilateral asymptomatic severe stenosis of the internal carotid artery (ICA) by comparison with unoperated patients.

Methods: Patients with age ≤75 years and unilateral asymptomatic severe stenosis (≥70%) of the cervical ICA underwent CEA with antiplatelet therapy (surgically treated group: 116 patients) or antiplatelet therapy alone or neither (medically treated group: 45 patients). For the surgically treated group, neuropsychological testing and brain perfusion measurement using single-photon emission computed tomography were performed within one month before surgery and one month after surgery. For the medically treated group, the same testing and measurement were performed twice at an interval of 1 to 2 months.

Results: None of the operated patients developed new major ischemic events after surgery or intraoperative cerebral hyperperfusion. None of the patients in the medically treated group experienced neurological deficits including transient ischemic attacks during the study period. The incidence of patients with interval cognitive improvement was significantly greater in the surgically treated group (11 patients: 9%) than in the medically treated group (0%) (p = 0.0352). The incidence of patients with interval brain perfusion improvement in the ipsilateral cerebral hemisphere was significantly greater in the surgically treated group (24 patients: 21%) than in the medically treated group (0%) (p = 0.0003).

Conclusions: Uncomplicated CEA may improve cognitive function and brain perfusion in patients with unilateral asymptomatic severe stenosis of the ICA when compared with unoperated patients.     

颈内动脉血泡样动脉瘤的CTA诊断

目的 分析颈内动脉血泡样动脉瘤(BBA)CT三维血管重建(CTA)的诊断价值及形态特征. 方法 回顾性分析广州军区广州总医院神经外科自2008年1月至2009年12月收治的143例自发性蛛网膜下腔出血(SAH)患者资料.所有患者均先后行CTA及DSA检查,并对结果进行对比分析. 结果 所有患者经平扫CT诊断为自发性SAH,其中6例经DSA确诊为颈内动脉BBA.该6例患者中4例在DSA检查之前即经CTA确诊,未经CTA确诊的2例患者中1例后虽经DSA检查明确,但回顾分析CTA仍未发现明确病变.全部6例患者均经血管内支架治疗,术后均单纯经DSA随访,平均随访时间8.3个月(6～18个月).4例患者复发并再手术. 结论 当自发性SAH经CTA检查未发现明确原因时,有必要进行详细的DSA检查,以除外是否存在颈内动脉BBA.     

Patency and flow velocity profiles in the internal carotid artery assessed by digital subtraction angiography and Doppler studies two years after endarterectomy

A follow-up of 55 patients 2 years after a total of 60 carotid endarterectomies. Fifty-two patients who had a total of 57 endarterectomies survived the first 2 post-operative years and were re-examined using pulsed Doppler spectral analysis and intravenous digital subtraction angiography (IVDSA). One patient had died following a stroke and 2 after a cardiac infarction. The Doppler and IVDSA examinations revealed a non-symptomatic restenosis of the relevant internal carotid artery in 2 patients. There were no relevant occlusions and no symptomatic re-stenoses were detected. Spectral spreading of the Doppler signal at the site of the endarterectomy was found in 18% of the internal carotid arteries, whereas wall irregularities (diameter reduction less than 10%) were demonstrated in 25% by IVDSA. A stenosis or occlusion was found in 14 (25%) of the 57 ipsilateral external carotid arteries.