Atherosclerotic disease of the middle cerebral artery

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

AIMS

Remote 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.

METHODS

This 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.

RESULTS

In 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.

CONCLUSION

In 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.

ATHEROMATOSIS OF THE BRAIN-SUPPLYING ARTERIES: CIRCLE OF WILLIS, BASILAR, VERTEBRAL AND THEIR BRANCHES

PURPOSE

Atherosclerotic plaques in the brain-supplying arteries are slowly-developing alterations of vascular structures that can lead to neurological impairment due to stenosis and insufficient oxygenation of eloquent brain areas. The aim of this study is to provide detailed demographic information related to the incidence of atherosclerotic plaques in the cerebral arteries.

MATERIAL AND METHODS

Forty-eight circles of Willis (21 men, 21 women, mean age: 70.26, six samples unknown) were macroscopically analyzed for length, diameter, and presence of atherosclerotic plaques. Statistical analysis was used to identify potential differences in the locations and frequencies of atherosclerotic plaques in relation to age and sex.

RESULTS

The study sample revealed 261 atherosclerotic plaques. The key findings were significant correlations between plaque development and age and between plaque location and age; however, there was no significant sex difference.

CONCLUSION

The upper and lower branches of the middle cerebral artery (MCA) were novel locations predisposing to plaque development. A cut-off value at 60 years revealed a significant difference in plaque development and distribution. There were no significant sex differences in the occurrence of atherosclerotic plaques.

Significance of high resolution MRI in the identification of carotid plaque

The stability of carotid artery plaque serves a key role in the occurrence of stroke. The present study was based on the recruitment of patients with acute ischemic cerebrovascular disease. High-resolution magnetic resonance imaging (HR-MRI) was used to identify the nature of carotid artery plaque, and the results were then used to manage the high-risk group of stroke. The patients were divided equally into a symptomatic group (36 cases) and an asymptomatic group (36 cases). According to the degree of carotid artery stenosis, the patients were divided into mild, moderate and severe stenosis groups, each group comprising 12 patients, and HR-MRI was performed. The proportion of patients with vulnerable plaque in the symptomatic group was higher compared with that in the asymptomatic group (P<0.05). The more severe the stenosis, the higher the proportion of vulnerable plaque that was identified (P<0.05). Compared with carotid ultrasound, HR-MRI was indicated to have the capability to both identify and quantify the different components in the plaque, allowing an assessment of its properties. In conclusion, the present study demonstrated that carotid HR-MRI is able to distinguish and quantify the different components of plaque, which may prove to be helpful for the hierarchical management of a population at high risk of stroke.

Recent glycemic control can predict the progressive motor deficits of acute subcortical infarction with diabetes or prediabetes

BACKGROUND AND PURPOSE

The predictors of progressive motor deficits in acute subcortical infarctions are still controversial. It is not known whether glycemic control influences on stroke progression.

METHODS

A total of 268 consecutive patients with diabetes or prediabetes who had acute (< 24 h) subcortical infarction were enrolled. (1) All patients were divided into 4 groups by quartile of glycated hemoglobin (HbA1c). (2) Only the patients with diabetes were divided by effective glycemic control. Progressive motor deficits were prospectively captured and defined as an increase of motor score ≥ 1 on the upper or lower limb items of the National Institute of Health Stroke Scale within 72 h from stroke onset.

RESULTS

Progressive motor deficits occur in 8/78 (10.3%) for ≤ 5.9, 15/61 (24.6%) for 6.0-6.4, 16/62 (25.8%) for 6.5-7.4, and 30/67 (44.8%) for ≥ 7.5. In diabetic patients alone, those occur in 5/37 (13.5%) for ≤ 6.5, 10/42 (23.8%) for 6.6-7.0, 12/42 (28.6%) for 7.1-8.0, and 24/50 (48.0%) for ≥ 8.1. An adjusted OR of progressive motor deficits was 2.61 (95% confidence interval [CI] 0.98-7.00, P = .056) for 6.0-6.4, 3.42 (95% CI 1.27-9.18, P = .015) for 6.5-7.4, and 6.65 (95% CI 2.38-18.62, P < .001) for ≥ 7.5. In diabetic patients alone, those were 3.15 (95% CI 0.89-11.15, P = .075) for 6.6-7.0, 2.90 (95% CI 0.79-10.61, P = .107) for 7.1-8.0, and 4.17 (95% CI 1.07-16.25, P = .038) for ≥ 8.1. The optimal cutoff value of HbA1c was 6.65% in discriminating progressive motor deficits.

CONCLUSION

Increased HbA1c was associated with higher incidence of progressive motor deficits in acute subcortical infarction with diabetes and prediabetes.

Intracranial Atherosclerosis is the Most Common Stroke Subtype: Ten-year Data from Hyderabad Stroke Registry (India)

Aim:

Limited data regarding stroke subtypes exist from South Asian countries. The aim of the study was to determine the pattern of ischemic stroke subtypes and their associated risk factors, in a 10-year long hospital-based registry in the South Indian city of Hyderabad.

Materials and Methods:

The Hyderabad stroke registry systematically collected clinical, radiological, and laboratory data of fully investigated consecutive stroke patients and studied pattern of ischemic stroke subtypes and their risk factor association.

Results:

The cohort comprised of 2642 patients: 2072 (78.4%) were ischemic and 570 (21.6%) were hemorrhagic strokes. In the ischemic stroke cohort, the mean age was 54.1 years and 1622 (78.3%) were men. The most common ischemic stroke subtype was large artery atherosclerosis (LAA) comprising 37.6% (n = 779), followed by small vessel occlusion comprising 19.9% (n = 413) and cardioembolism 11% (n = 228). Stroke of other determined etiologies constituted 4.2% (n = 86) and stroke of undetermined etiology was observed in 27.3%. Among patients with LAA, 610 (78.3%) patients had intracranial and 169 (21.7%) had extracranial disease as the underlying mechanism. Risk factor profile demonstrated that hyperlipidemia was significantly associated with LAA and ischemic heart disease with cardioembolic strokes.

Conclusions:

The study reveals a distinct pattern of ischemic stroke subtypes in the Indian context that has overlapping features of registries from West and East Asian countries. Both large artery and small vessel diseases are substantially represented with a predominance of intracranial atherosclerosis. The study results have significant implications for developing preventive and management strategies for stroke care and research in India.

Stenting for intracranial stenosis: potential future for the prevention of disabling or fatal stroke

Intracranial stenosis is a common cause of ischaemic strokes, in particular, in the Asian, African and Hispanic populations. The randomised multicentre study Stenting and Aggressive Medical Management for the Prevention of Recurrent stroke in Intracranial Stenosis (SAMMPRIS) showed 14.7% risk of stroke or death in the stenting group versus 5.8% in the medical group at 30 days, and 23% in the stenting group versus 15% in the medical group at a median follow-up of 32.4 months. The results demonstrated superiority of medical management over stenting and have almost put the intracranial stenting to rest in recent years. Of note, 16 patients (7.1%) in the stenting group had disabling or fatal stroke within 30 days mostly due to periprocedural complications as compared with 4 patients (1.8%) in the medical group. In contrast, 5 patients (2.2%) in the stenting group and 14 patients (6.2%) in the medical group had a disabling or fatal stroke beyond 30 days, indicating significant benefit of stenting if periprocedural complications can be reduced. Recently, the results of the Chinese Angioplasty and Stenting for Symptomatic Intracranial Severe Stenosis trial and the Wingspan Stent System Post Market Surveillance Study (WEAVE trial) showed 2%-2.7% periprocedural complications. It is time to evaluate the role of intracranial stenting for the prevention of disabling or fatal stroke.

Comparison of Therapeutic Efficacy Between Isolated Encephaloduroarteriosynangiosis and Medical Treatment in Patients with Atherosclerotic Middle Cerebral Artery Occlusion

BACKGROUND

Encephaloduroarteriosynangiosis (EDAS) as a form of indirect revascularization has been recently proposed as a potentially promising alternative for patients with intracranial atherosclerotic disease (ICAD). The object of this study was to compare the prognostic roles between isolated EDAS and medical therapy in patients with atherosclerotic middle cerebral artery occlusion (MCAO).

METHODS

From January 2014 to June 2017, 125 patients with atherosclerotic MCAO were enrolled in this prospective nonrandomized controlled cohort study. Patients who underwent EDAS (n = 60) were compared with those treated medically (n = 65). Early and late adverse events and functional outcomes including memory ability were compared between groups.

RESULTS

During 23.7 months of mean follow-up, rates of adverse events, including ischemic events in the territory of the qualifying middle cerebral artery, and death from any causes, were not significantly different in patients treated with EDAS and with medical therapy (6.7% vs. 12.3%; P = 0.285). Landmark analyses showed that at initial 6-month follow-up, there was no significant difference for adverse event rates, whereas the opposite finding was shown for the subsequent period (EDAS 1/57 [1.7%] vs. medical management 7/64 [10.9%]; P = 0.024). The P value for the interaction between time (first 6 months vs. subsequent period) was 0.044. No significant differences were found with respect to neural function status and cognitive ability.

CONCLUSIONS

In the long-term, isolated EDAS can be considered effective and safe for patients with atherosclerotic MCAO, whereas it may need additional medical therapy support in the short-term.

Stroke Caused by Atherosclerosis of the Major Intracranial Arteries

Our goal in this review is to discuss the pathophysiology, diagnosis, and treatment of stroke caused by atherosclerosis of the major intracranial arteries. References for the review were identified by searching PubMed for related studies published from 1955 to June 2016 using search terms intracranial stenosis and intracranial atherosclerosis. Reference sections of published randomized clinical trials and previously published reviews were searched for additional references. Intracranial atherosclerotic disease is a highly prevalent cause of stroke that is associated with a high risk of recurrent stroke. It is more prevalent among blacks, Hispanics, and Asians compared with whites. Diabetes mellitus, hypertension, metabolic syndrome, smoking, hyperlipidemia, and a sedentary lifestyle are the major modifiable risk factors associated with intracranial atherosclerotic disease. Randomized clinical trials comparing aggressive management (dual antiplatelet treatment for 90 days followed by aspirin monotherapy and intensive management of vascular risk factors) with intracranial stenting plus aggressive medical management have shown medical management alone to be safer and more effective for preventing stroke. As such, aggressive medical management has become the standard of care for symptomatic patients with intracranial atherosclerotic disease. Nevertheless, there are subgroups of patients who are still at high risk of stroke despite being treated with aggressive medical management. Future research should aim to establish clinical, serological, and imaging biomarkers to identify high-risk patients, and clinical trials evaluating novel therapies should be focused on these patients.

Update on Endovascular Treatment of Cerebrovascular Diseases

Several developments in endovascular technology have greatly expanded the application of these techniques to treat extra- and intracranial cerebrovascular diseases. This review explores the indications, techniques, and clinical results for endovascular treatment of ischemic stroke and intracranial stenoses, aneurysms, and arteriovenous malformations.

Bloodletting at Jing-well points decreases interstitial fluid flow in the thalamus of rats

OBJECTIVE

To investigate the changes in the neuronal microenvironment of the middle cerebral artery (MCA) territory induced by Jing-well points bloodletting acupuncture (WPBA) and to explore the neuroprotective mechanism of WPBA in stroke.

METHODS

Adult male Sprague Dawley (n = 32) rats were randomly divided into four groups of eight animals each: WPBA-thalamus group (WT), WPBA-caudate nucleus group (WC), sham-control thalamus group (ST) and sham-control caudate nucleus group (SC). Animals in the WT and WC groups received 2 µL of the extracellular tracer gadolinium-diethylene triamine pentaacetic acid (Gd-DTPA) injected into the thalamus or caudate nucleus, respectively, and 12 Jing-well points in the distal ends of the rats' digits were used for WPBA. Although 2 µL of Gd-DTPA was injected into the thalamus or caudate nucleus, respectively, for animals in the two sham groups (ST and SC), no acupuncture or bloodletting was performed. Brain extracellular space and interstitial fluid flow parameters were measured using Gd-DTPA-enhanced magnetic resonance imaging.

RESULTS

The brain interstitial fluid flow speed was decreased in the thalamus after WPBA, with a significantly lower Gd-DTPA clearance rate and longer half-life of Gd-DTPA in the thalamus of treated rats than those in sham-control rats [WPBA-treated rats' clearance rate, (7.47 ± 3.15) x 10(-5)/s (P.= 0.009); half-life, (1.52 ± 0.13) h, P = 0.000]. By contrast, no significant changes in brain extracellular space and interstitial fluid flow parameters were detected in the caudate nucleus after WPBA (P = 0.649). In addition, no differences in the morphology of the brain extracellular space or the final distribution of the traced brain interstitial fluid were demonstrated between the WT and WC groups (P = 0.631, P = 0.970, respectively).

CONCLUSION

The WPBA decreased the speed of the local thalamic ISF flow in rats, which is assumed to be a beneficial protection by down-modulated the metabolic rate of the attacked neurons under stroke.

Research on intracranial atherosclerosis from the East and west: why are the results different?

Intracranial atherosclerosis (ICAS) is a major cause of stroke worldwide and is more common in Asians than Caucasians. The study results from the East and West are generally similar, but notable differences exist. For example, studies from the East have reported that ICAS is associated with young age, whereas ICAS seems to be associated with old age in the West. Studies from the East have strongly suggested that mild ICAS associated with branch occlusion is one of the main causes of single subcortical infarction, whereas this aspect has not been considered in stroke classification systems developed in the West. While clopidogrel is commonly used in patients with large artery disease in the West, cilostazol has been more extensively studied and commonly used in ICAS patients in the East. A randomized controlled study from the West reported negative results regarding the efficacy of stenting in ICAS patients due largely to a relatively high rate of periprocedural adverse events, whereas research papers from the East have reported a relatively lower rate of complications. Studies to narrow these East-West gaps should be performed, including risk factor studies using homogenous ethnic populations, studies investigating appropriate classification systems, drug trials in different ethnic populations, and rigorous high standard randomized controlled studies on the efficacy of stenting in Eastern populations.

Infarct patterns, collaterals and likely causative mechanisms of stroke in symptomatic intracranial atherosclerosis

BACKGROUND

There are limited data on the specific mechanisms of stroke in patients with intracranial atherosclerotic stenosis (ICAS). We undertook this study to describe infarct patterns and likely mechanisms of stroke in a large cohort of patients with ICAS, and to evaluate the relationship of these infarct patterns to angiographic features (collaterals, stenosis location and stenosis severity).

METHODS

We evaluated infarct patterns in the territory of a stenotic intracranial artery on neuroimaging performed at baseline and during follow-up if a recurrent stroke occurred in patients enrolled in the Warfarin-Aspirin Symptomatic Intracranial Disease (WASID) trial. We defined the likely mechanism of stroke (artery-to-artery embolism, perforator occlusion, hypoperfusion or mixed) according to the site of ICAS and based on the infarct patterns on neuroimaging. Collaterals were assessed using American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN/SIR) grades, and stenosis severity using the WASID trial's measurement technique. We evaluated the association of infarct patterns with angiographic features using χ(2) tests.

RESULTS

The likely mechanisms of stroke based on the infarct patterns at baseline in the 136 patients included in the study were artery-to-artery embolism (n = 69; 50.7%), perforator occlusion (n = 34; 25%), hypoperfusion (n = 12; 8.8%) and mixed (n = 21; 15.5%). Perforator-occlusive infarcts were more frequent in the posterior circulation, and mixed patterns were more prevalent in the anterior circulation (both p < 0.01). Most of the mixed patterns in the anterior circulation combined small pial or scattered multiple cortical infarcts with infarcts in border-zone regions, especially the cortical ones. Isolated border-zone infarcts were not significantly associated with a poor grading for collaterals or the severity of stenosis. Among 47 patients with a recurrent infarct during follow-up, the infarct patterns suggested an artery-to-artery embolic mechanism in 29 (61.7%).

CONCLUSIONS

Artery-to-artery embolism is probably the most common mechanism of stroke in both the anterior and the posterior circulations in patients with ICAS. An extension of intracranial atherosclerosis at the site of stenosis into adjacent perforators also appears to be a common mechanism of stroke, particularly in the posterior circulation, whereas hypoperfusion as the sole mechanism is relatively uncommon. Further research is important to accurately establish the specific mechanisms of stroke in patients with ICAS, since preliminary data suggest that the underlying mechanism of stroke is an important determinant of prognosis.

Atherosclerotic intracranial arterial stenosis: risk factors, diagnosis, and treatment

Intracranial atherosclerosis is one of the most common causes of stroke worldwide and is associated with a high risk of recurrent stroke. New therapeutic approaches to treat this high-risk disease include dual antiplatelet treatment, intensive management of risk factors, and endovascular therapy. Early data from randomised trials indicate that aggressive medical therapy is better than stenting for prevention of recurrent stroke in high-risk patients with atherosclerotic stenosis of a major intracranial artery. Nevertheless, there are subgroups of patients who remain at high risk of stroke despite aggressive medical therapy. Further research is needed to identify these high-risk subgroups and to develop more effective treatments. Non-invasive vascular imaging methods that could be used to identify high-risk patients include fractional flow on magnetic resonance angiography (MRA), quantitative MRA, and high-resolution MRI of the atherosclerotic plaque. Alternative therapies to consider for future clinical trials include angioplasty alone, indirect surgical bypass procedures, ischaemic preconditioning, and new anticoagulants (direct thrombin or Xa inhibitors).

Recent advances in endoluminal revascularization for intracranial atherosclerotic disease

More than 750,000 strokes occur annually in the United States. Of these, 8-10% are due to intracranial atherosclerosis. Less than 50% of patients with strokes from intracranial atherosclerosis will have a transient ischemic attack. For those patients with symptomatic intracranial atherosclerosis, the prognosis is poor; and the recent Warfarin-Aspirin Symptomatic Intracranial Stenosis (WASID) trial results have demonstrated the high risk of warfarin without clear benefit. Intracranial angioplasty and stenting is emerging as a viable and effective treatment alternative for patients with symptomatic intracranial stenosis. Advances in stent design, endovascular wires, and catheters and balloons are allowing endovascular surgeons to safely treat intracranial atherosclerosis. Wider clinical experience has led to refinement of patient selection and endoluminal techniques. Drug eluting-stents have the promise of decreasing the risk of restenosis. In this review, the most recent clinical, laboratory, and technical details for the treatment of intracranial angioplasty and stenting are discussed.

Branch atheromatous plaque: a major cause of lacunar infarction (high-resolution MRI study)

BACKGROUND

Lacunar infarctions account for up to 25% of all ischemic strokes and, thus, constitute a numerically important subgroup. It is important that the two pathogeneses of lacunar infarction, that is, small-vessel occlusion and branch atheromatous disease, be differentiated because prognoses and treatment strategies differ. The authors evaluated the presence of branch atheromatous plaque in parent arteries that supply lacunar infarcts by high-resolution magnetic resonance imaging (HR-MRI).

METHODS

HR-MRI was performed in 15 patients with (1) a clinical presentation consistent with classical lacunar syndromes; (2) an acute lacunar infarction by diffusion-weighted imaging, measuring ≤20 mm in maximal diameter; (3) a magnetic resonance angiography showing a normal middle cerebral artery or basilar artery supplying the ischemic lesion, and (4) no other obvious etiology for small-vessel distribution ischemic stroke.

RESULTS

The median time of vessel wall imaging after index events was 4 days (range, 2-15 days). Six of the 15 patients had a lacunar infarction in the middle cerebral artery territory, and 9 had a lesion in the basilar artery territory. HR-MRI detected underlying atheromatous plaques in 9 patients (60%) with a lacunar infarction. In these 9 patients, asymptomatic intracranial atherosclerotic stenosis was more frequent compared to patients without branch atheromatous plaque (55.6 vs. 16.7%). In pontine infarctions, ischemic lesions that extended to the pial base of the pons were more frequent in patients with branch atheromatous plaques (83.3 vs. 33.3%), and all the ischemic lesions and atheromatous plaques were on the same side (right, n = 2; left, n = 4). All plaques responsible for acute symptomatic lacunar infarction were enhanced in contrast-enhanced T1-weighted HR-MR images.

CONCLUSIONS

HR-MRI results enabled underlying symptomatic branch atheromatous disease to be detected in lacunar infarction patients. The experience gained during this study indicates that HR-MRI better delineates intracranial arterial lesions, suggesting that its use will lead to a further understanding of the mechanisms involved in stroke.

Long-term prognosis of symptomatic isolated middle cerebral artery disease in Korean stroke patients

Background

This study aimed to investigate the long-term mortality and recurrence rate of stroke in first-time stroke patients with symptomatic isolated middle cerebral artery disease (MCAD) under medical management.

Methods

We identified 141 first ever stroke patients (mean age, 64.4 ± 12.5 years; 53% male) with symptomatic isolated MCAD. MCAD was defined as significant stenosis of more than 50% or occlusion of the MCA as revealed by MR angiography. The median follow-up was 27.7 months. We determined a cumulative rate of stroke recurrence and mortality by Kaplan-Meier survival analyses and sought predictors using the Cox proportional hazard model.

Results

The cumulative composite outcome rate (stroke recurrence or any-cause death) was 14%, 19%, 22%, and 28% at years 1, 2, 3, and 5, respectively. The annual recurrence rate of stroke was 4.1%. The presence of diabetes mellitus was the only significant independent predictor of stroke recurrence or any cause of death in multivariate analyses of Cox proportional hazard model adjusted for any plausible potential confounding factors.

Conclusions

We estimated the long-term prognosis of stroke patients with isolated symptomatic MCAD under current medical management in Korea. Diabetes mellitus was found to be a significant predictor for stroke recurrence and mortality.

Efficacy of cilostazol for intracranial arterial stenosis evaluated by digital subtraction angiography/magnetic resonance angiography

INTRODUCTION

Intracranial arterial stenosis is an important factor in the development of cerebral infarction; however, no effective treatment has been established. A phosphodiesterase 3 (PDE3) inhibitor, cilostazol, has been reported to suppress progression of symptomatic intracranial arterial stenosis in combination with aspirin, but the study used magnetic resonance angiography (MRA) for evaluation, which is not considered optimal for assessment of stenotic lesions.

METHODS

A preliminary study was conducted to investigate the efficacy of cilostazol using MRA and intra-arterial digital subtraction angiography (DSA). DSA was performed in 18 patients for whom intracranial arterial stenosis was suspected from MRA. Cilostazol (200 mg/day) was administered orally for 1 year to 13 patients with 16 lesions (nine symptomatic, seven asymptomatic) confirmed by DSA. MRA and DSA were repeated at 6 and 12 months.

RESULTS

Through MRA at 6 and 12 months, regression was observed in nine (56.3%) and eight (50.0%) patients, six (37.5%) and seven (43.8%) patients remained stationary, and one (6.3%) and one (6.3%) patient progressed, respectively. From DSA, percent stenosis for all lesions significantly improved from 49.2 (±15.4%) to 42.6 (±12.7%) at 12 months (P=0.023). In nine symptomatic lesions, stenosis was 55.3 (±7.3%) at baseline, 46.3 (±12.5%) at 6 months (P=0.029), and 47.7 (±9.9%) at 12 months (P=0.049). In contrast, in seven asymptomatic lesions, no significant improvement was observed at 6 months (P=0.113) or 12 months (P=0.157). When evaluated by severity, there was a significant improvement in 11 lesions with ≥50% stenosis, but no significant improvement was observed in five lesions with <50% stenosis. No patient developed symptomatic stroke events.

CONCLUSION

Cilostazol may induce improvement of symptomatic intracranial arterial stenosis or severe lesions. A combination of MRA and DSA might be another diagnostic option for more precise examination.

Wingspan stenting with modified predilation for symptomatic middle cerebral artery stenosis

OBJECTIVES

Our purpose was to assess the feasibility, safety, and effectiveness of a modified predilation for middle cerebral artery (MCA) stenosis.

BACKGROUND

Wingspan stenting of MCA remains a technical challenge, and rates of residual stenosis and restenosis must be lowered.

METHODS

A series of 48 patients with symptomatic MCA stenosis greater than 50% and refractory to medical therapy underwent Wingspan stenting with different balloon/artery ratios before (group 1, Boston guidelines predilation) or after (group 2, modified predilation) July of 2008. Technical success, periprocedural complications, recurrent symptoms, and restenosis were assessed retrospectively, and risk factors for restenosis were analyzed using logistic regression.

RESULTS

Successful stenting occurred in 48 of 49 (98%) lesions. Primary endpoints within 30 days included one (2.12%) minor stroke and two (4.26%) transient ischemic attacks. Stenoses were reduced from 77.11% ± 10.09% to 27.50% ± 6.91% in group 1 versus from 72.56% ± 10.46% to 8.20% ± 5.41% in group 2. A total of 43 patients were followed up for 12.92 ± 5.08 months, and recurrent stroke or transient ischemic attack occurred in two (4.65%) patients. Vessels were followed with transcranial Doppler (43 vessels), angiography (23 vessels), or computed tomographic angiography (one vessel). The restenosis rate was 8 of 18 (44%) in group 1 and 3 of 25 (12%) in group 2. Restenosis was associated with residual stenosis and diabetes.

CONCLUSIONS

Wingspan stenting for symptomatic MCA stenosis can be performed with high success and low complication rates, and modified predilation with the Gateway balloon can reduce the rates of residual stenosis and restenosis.

Extracranial-intracranial bypass in atherosclerotic cerebrovascular disease: report of a single centre experience

Despite the failure of the international extracranial-intracranial (EC-IC) bypass study in showing the benefit of bypass procedure for prevention of stroke recurrence, it has been regarded to be beneficial in a subgroup of well-selected patients with haemodynamic impairment. This report includes the EC-IC bypass experience of a single centre over a period of 14 years. All consecutive 72 patients with atherosclerotic occlusive cerebrovascular lesions associated with haemodynamic compromise treated by EC-IC bypass surgery were retrospectively reviewed. Pre-operatively, 61% of patients presented with minor stroke and the remaining 39% with recurrent transient ischemic attacks (TIAs) despite maximal medical therapy. Angiography revealed a unilateral internal carotid artery (ICA) stenosis/occlusion in 79%, bilateral ICA stenosis/occlusion in 15%, MCA stenosis/occlusion in 3% and other multiple vessel stenosis/occlusion in 3% of the cases. H(2)(15)O positron emission tomography (PET) or 99mTc-HMPAO SPECT with acetazolamide challenge was performed for haemodynamic evaluation of the cerebral blood flow (CBF). All the patients had impaired haemodynamics pre-operatively in terms of reduced regional cerebrovascular reserve capacity and rCBF. Standard STA-MCA bypass procedure was performed in all patients. A total of 68 patients with 82 bypasses were reviewed with a mean follow-up period of 34 months. Stroke recurrence took place in 10 patients (15%) resulting in an annual stroke risk of 5%. Improved cerebral haemodynamics was documented in 81% of revascularised hemispheres. Patients with unchanged or worse haemodynamic parameters had significantly more post-operative TIAs or strokes when compared to those with improved perfusion reserves (30% vs.5% of patients, p<0.05). In conclusion, EC-IC bypass procedure in selected patients with occlusive cerebrovascular lesions associated with haemodynamic impairment has revealed to be effective for prevention of further cerebral ischemia, when compared with a stroke risk rate of 15% reported to date in patients only under antiplatelet agents or anticoagulant therapy.

Angioplasty and stenting of atherosclerotic middle cerebral arteries with Wingspan: evaluation of clinical outcome, restenosis, and procedure outcome

BACKGROUND AND PURPOSE

MCA is a common location of intracranial stenosis. It is relatively more peripherally located and of a smaller caliber, and could therefore be a site technically more challenging and risky for angioplasty and stenting. The study aimed to evaluate the clinical outcome, restenosis rate, and procedural safety of Wingspan stent placement for atherosclerosis in the MCA compared with stenosis in other arteries.

MATERIALS AND METHODS

Patients who underwent Wingspan stent placement for symptomatic intracranial stenosis of ≥70% (or stenosis of ≥50% for recurrent ischemia despite medical therapy) were recruited prospectively and allocated into a study group (MCA stenosis, n=35) and a control group (other stenosis, n=25). Primary end points were the following: 1) all stroke or death rate at 1 year, and 2) significant in-stent restenosis rate at 1 year. Secondary end points were the following: 1) periprocedural complications within 24 hours, rate of TIA during the procedure, all stroke or death rate within 30 days; and 2) the inability to complete the procedure due to technical problems.

RESULTS

Results of study group versus the control group were the following: degree of stenosis, 78.4 ± 10.9% versus 72.5 ± 11.2% (P value=.0456); diameter of stenosis, 0.6 ± 0.3 versus 1.0 ± 0.5 mm (P=.0017); all stroke or death rate at 1 year, 14.3% versus 12% (OR=1.22); in-stent restenosis rate at 1 year, 10% versus 10.5% (OR=1.05); periprocedural complication rate at 24 hours, 2.9% versus 4% (OR=0.70); TIA rate during the procedure, 8.6% versus 4% (OR=2.25); all stroke or death rate at 30 days, 5.7% versus 12% (OR=0.44); and technical failure rate, 2.9% versus 0%.

CONCLUSIONS

In this study, there were no significant differences in procedural safety, patient outcome, and restenosis rates of stent placement between the group with MCA stenosis and the group with stenoses located at other sites.

Wingspan stent for symptomatic M1 stenosis of middle cerebral artery

OBJECTIVE

Stent placement for intracranial atherosclerotic stenosis has become an alternative treatment technique; however, stent placement for middle cerebral artery (MCA) stenosis remains a technical and clinical challenge. Our purpose was to assess the safety and feasibility of Wingspan stent for patients with symptomatic M1 stenosis, and its initial effect on prevention of ischemic events.

METHODS

Fifty-three cases with recurrent symptomatic MCA stenosis resistant to medical therapy treated by self-expanding stent were reviewed retrospectively (average 58±18.5 years old, 19 women). All patients underwent angioplasty and stenting with the Gateway balloon-Wingspan stent system, and advised follow-up with DSA or TCD at 6th month.

RESULTS

Patients had an average stenosis ratio of 76.5±15.4% prior to the treatment. Of the 53 patients, the technical success rate was 98.1% as a whole (52/53). The mean degree of stenosis reduced from (76.5±15.4)% to (18.2±11.3)%. Complications associated with the procedure include subarachnoid hemorrhage (1.89%) and occlusion (3.78%) occurred. During a follow-up of 6 months, there was no recurrence of transient ischemic attack or stroke in 52 cases with successful stenting. Cerebral hemodynamics of MCA using transcranial Doppler monitoring were at normal level (<120 cm/s) in 41 follow-up patients. The follow up angiography at 6 month post-procedure was conducted in 32 patients and showed good patency in stented vessels.

CONCLUSIONS

Wingspan stent for symptomatic stenosis of middle cerebral artery is a safe and feasible procedure. It improves clinical outcome in the intermediate follow up, but its long-term effect remains to be further evaluated.

Middle cerebral artery occlusive disease: the New England Medical Center Stroke Registry

To analyze the clinical features, vascular lesions, and infarct distribution in Asian and white patients with middle cerebral artery (MCA) territory ischemia, we studied age, sex, race, risk factors, angiographic, and neuroimaging findings among patients in the New England Medical Center Stroke Registry. We included patients with well-defined intrinsic occlusive lesions of the MCAs and patients with embolic MCA territory infarcts. Among 695 patients in the stroke registry, 89 (12.8%) qualified. They had 28 MCA intrinsic stenoses, 17 MCA embolic occlusions (cardiogenic or unknown origin), and 44 carotid artery (CA) stenoses or occlusions. MCA intrinsic disease patients were more often Asians and women, and more often had hypertension. Asians were older than whites. Coronary artery disease (27%), peripheral vascular disease (20.5%), and smoking (39%) were more common in CA disease patients. The most common site of MCA intrinsic stenosis (78%) and embolic occlusion (59%) was the mainstem MCA. Infarcts in patients with MCA intrinsic disease mostly involved the striatocapsular area (61%). Infarcts in patients with MCA embolic occlusion (75%) and CA disease (43%) most often involved the parietal lobe. In our hospital, most patients with MCA intrinsic disease are Asians and women and have hypertension and striatocapsular infarctions. Asian patients are usually older than white patients. The most common site of vascular lesions is the mainstem MCA.

Therapeutic modalities in symptomatic intracranial arterial occlusive disease

Intracranial atherosclerotic disease (ICAD) is a frequent cause of stroke that is sometimes underdiagnosed. In this review, we survey the literature concerning ICAD and present the prognostic factors and the therapeutic options pertinent to it by comparing medical, surgical and endovascular approaches.

Reporting standards for angioplasty and stent-assisted angioplasty for intracranial atherosclerosis

BACKGROUND AND PURPOSE

Intracranial cerebral atherosclerosis causes ischemic stroke in a significant number of patients. Technological advances over the past 10 years have enabled endovascular treatment of intracranial atherosclerotic stenosis. The number of patients treated with angioplasty or stent-assisted angioplasty for this condition is increasing. Given the lack of universally accepted definitions, the goal of this document is to provide consensus recommendations for reporting standards, terminology, and written definitions when reporting clinical and radiological evaluation, technique, and outcome of endovascular treatment using angioplasty or stent-assisted angioplasty for stenotic and occlusive intracranial atherosclerosis.

SUMMARY OF REPORT

This article was written under the auspices of Joint Writing Group of the Technology Assessment Committee, Society of NeuroInterventional Surgery, Society of Interventional Radiology; Joint Section on Cerebrovascular Neurosurgery of the American Association of Neurological Surgeons and Congress of Neurological Surgeons; and the Section of Stroke and Interventional Neurology of the American Academy of Neurology. A computerized search of the National Library of Medicine database of literature (PubMed) from January 1997 to December 2007 was conducted with the goal to identify published endovascular cerebrovascular interventional data in stenotic intracranial atherosclerosis that could be used as benchmarks for quality assessment. We sought to identify those risk adjustment variables that affect the likelihood of success and complications. This document offers the rationale for different clinical and technical considerations that may be important during the design of clinical trials for endovascular treatment of intracranial stenotic and occlusive atherosclerosis. Included in this guidance document are suggestions for uniform reporting standards for such trials. These definitions and standards are primarily intended for research purposes; however, they should also be helpful in clinical practice and applicable to all publications.

CONCLUSION

In summary, the definitions proposed represent recommendations for constructing useful research data sets. The intent is to facilitate production of scientifically rigorous results capable of reliable comparisons between and among similar studies. In some cases, the definitions contained here are recommended by consensus of a panel of experts in this writing group for consistency in reporting and publication. These definitions should allow different groups to publish results that are directly comparable.

Case report of a patient who underwent thrombolysis of a "silent" thrombus in the middle cerebral artery

INTRODUCTION

Some stroke patients present with mild or absent measurable neurologic deficits in spite of a significant thromboembolic event. A thrombus in the distal region of the middle cerebral artery may have such a presentation. CT angiography in the acute phase helps to identify the culprit thrombus. Thrombolysis might be beneficial in these patients in spite of the lack of measurable neurologic deficits. We present a patient with a 'silent' thrombus in the middle cerebral artery.

CASE REPORT

A 70-year-old man presented with a history of fluctuating neurologic symptoms for 2 days. Neurologic examination at the time of presentation revealed no measurable deficits. CT angiography showed a thrombus in the M2 segment of the middle cerebral artery which was treated with intravenous thrombolysis. Patient did not have recurrence of symptoms after thrombolysis. MR angiogram a day after thrombolysis showed partial recanalization of the artery.

CONCLUSION

Some stroke patients with an intracranial thrombus may present with minimal or absent measurable neurologic deficits. CT angiography is a useful tool in identifying the thrombus. Intravenous thrombolysis may be beneficial in stroke patients presenting with a "silent" thrombus.

Treatment of symptomatic middle cerebral artery stenosis with balloon-mounted stents: long-term follow-up at a single center

OBJECTIVE

Primary stenting is a well-established treatment for coronary artery disease and has been applied to symptomatic intracranial stenosis in selected patients. This study reports a large case series of middle cerebral artery revascularization using balloon-mounted coronary stents.

METHODS

The series consisted of 113 consecutive patients with symptomatic middle cerebral artery stenosis and more than 70% occlusion who underwent intracranial stenting at a single center from 2001 to 2006. Technical success, periprocedural complications, recurrent symptoms, and restenosis were retrospectively reviewed. Risk factors for restenosis were analyzed using logistic regression and the chi(2) test.

RESULTS

The mean age of the patients was 48 +/- 11 years (range, 25-79 years). Seventy-three patients presented with transient ischemic attacks, and 40 patients were diagnosed with acute stroke. The technical success rate was 96.46%. The mean stenosis was reduced from 80.83 +/- 8.77% to 3.71 +/- 8.15%. The rate of stroke and death within 30 days was 4.42%. Eighty-nine patients were followed for an average period of 29 +/- 16 months (range, 9 months-5 years). Seventy-nine vessels were followed with transcranial Doppler and 36 vessels with angiography or computed tomographic angiography. Recurrent stroke or transient ischemic attacks occurred in 6 patients (6.74%). The restenosis rate was 20.25%. Restenosis was associated with diabetes and hyperlipidemia but not with age, sex, hypertension, or drug-eluting stent.

CONCLUSION

Primary stenting of symptomatic middle cerebral artery stenosis can be performed with high success and low complication rates. Randomized clinical studies are warranted to compare the safety and efficacy of various endovascular revascularization techniques with maximal medical therapy in patients with symptomatic intracranial atherosclerosis.

[Intracranial atherosclerosis]

Until recently, intracranial atheromatosis was a probably underdiagnosed clinicopathological entity that was rarely studied in depth. In the last years the advance and expansion in the use of non-invasive diagnostic tools have led intracranial atheromatosis to the front page among the most prevalent causes of stroke worldwide. Important efforts have been accomplished with the aim of identifying markers of poor outcome, which, besides the underlying mechanisms of cerebral ischemia in these patients, are the most important factors on which clinical and therapeutic decisions should be based. To date, the therapeutic armamentarium is scarce and far from optimun, regarding medical and endovascular measures. In this review we address the most important aspects of the natural history and cure treatment of intracranial atheromatosis.

Percutaneous transluminal angioplasty for atherosclerotic stenoses of intracranial vessels

SUMMARY

To study the efficacy and long-term outcome of percutaneous transluminal angioplasty (PTA) with/without stent placement for intracranial atherosclerotic stenoses, we reviewed our treated cases retrospectively. Between May 1992 and October 2003, PTA with/without stents was performed in 64 intracranial and skull base vessels in 62 patients, including 24 middle cerebral arteries, 16 internal carotid arteries, 13 vertebral arteries, and 11 basilar arteries. PTA was technically successful in 55 vessels (86%). However, four vessels (6%) failed to achieve satisfactory dilatation. We encountered five periprocedural strokes as symptomatic complications, for a mortality rate of 4.7% and a morbidity rate of 3.1%. All the patients with stent placements survived angioplasty without any complication. In the clinical follow-up available for one week to 11.5 years (mean, 4.7 years), there were three strokes related to the treated vessels. The annual stroke rate in the affected territory was estimated at 1.2% per year. According to these results, PTA for intracranial atherosclerotic stenoses seems to be a beneficial therapy for immediate anatomical results and long-term stroke prevention. Stent-assisted PTA could help patients achieve successful dilatation and avoid complications.

Warfarin and low-dose aspirin for stroke prevention from severe intracranial stenosis

Management of symptomatic, intracranial, large-arterial atherosclerosis is controversial. We assessed the safety and efficacy of combining warfarin and low-dose aspirin to prevent stroke from intracranial atherosclerotic stenosis failing prior treatment with either aspirin or warfarin. Patients with severe intracranial stenosis were prescribed combination therapy, warfarin (international normalized ratio [INR] 2 to 3) and aspirin 81 mg daily. Ten men and six women treated with combination therapy had one recurrent ischemic event during 382 months of therapy. No patient suffered a myocardial infarction or sudden vascular death. No serious hemorrhagic complication occurred. The combination of warfarin and low-dose aspirin seems safe and effective in preventing recurrent stroke from symptomatic, intracranial, large-arterial occlusive disease after failure with either aspirin or warfarin monotherapy.

Relation between interleukin-6 level and subclinical intracranial large-artery atherosclerosis

BACKGROUND

The levels of systemic inflammatory markers have been shown to predict future cardiovascular events, but whether they are associated with intracranial large-artery atherosclerosis is uncertain. We investigated the relation between the level of inflammatory markers interleukin-6 (IL-6) and high-sensitivity C-reactive protein (hsCRP) and subclinical intracranial large-artery atherosclerosis in patients with risk factors for atherosclerosis.

METHODS

Magnetic resonance angiography (MRA) was performed in 226 Japanese patients age range, 45-87 years without a history of cerebrovascular disease. Serum IL-6 and hsCRP and conventional risk factors for atherosclerosis were assessed.

RESULTS

Forty-six patients (20.4%) were found by MRA to have one or more intracranial steno-occlusive lesions. Mean IL-6 levels were higher in patients with intracranial large-artery atherosclerosis than in those without. In addition, patients in the highest IL-6 tertile had higher unadjusted odds ratio (OR) for intracranial large-artery atherosclerosis than that of those in the lowest tertile (OR 3.25, 95% CI; 1.42-7.39). These associations were only slightly attenuated upon adjustment for conventional atherosclerotic risk factors and carotid intima-media thickness.

CONCLUSIONS

Increased levels of IL-6 appear to be associated with intracranial large-artery disease, suggesting a role for the inflammatory process in atherosclerosis of intracranial large arteries.

Use of stents to treat intracranial cerebrovascular disease

Intracranial atherosclerosis is a common cause of stroke. Although it has been recognized for decades, the lack of successful treatment strategies has limited clinical interest until recently. We review the natural history and pathophysiology of intracranial atherosclerosis. Vascular biomechanics are important to define differences between cerebral arteries and extracranial vessels and partly explain the technical challenges facing cerebral artery revascularization as compared with revascularization of coronary arteries. Pharmacological interventions to prevent stroke have had limited success, but technological developments offer improved methods for endovascular revascularization of symptomatic and asymptomatic cerebral artery stenosis. Identification of appropriate candidates for treatment also remains a challenge, and our knowledge about the natural history of the disease is limited. At this time, patients with significant intracranial stenosis should receive information on the benefits and risks of revascularization therapy. Determining which patients should undergo revascularization procedures will require carefully planned, randomized clinical trials.

Primary stent therapy for symptomatic intracranial atherosclerotic stenosis: 1-year follow-up angiographic and midterm clinical outcomes

OBJECT

The aim of this study was to report 1-year angiographic follow-up results and midterm clinical outcomes in patients with symptomatic intracranial atherosclerotic lesions treated with stent placement.

METHODS

Ten patients with ischemic symptoms referable to stenotic intracranial atherosclerotic arteries, with greater than 60% stenosis, underwent elective surgery in which a primary stent was placed. All patients underwent pretreatment (> or =1 week) combination oral antiplatelet (clopidogrel and aspirin) therapy and long-term (6-month) combination oral antiplatelet (clopidogrel and aspirin) therapy after stents were placed. The procedure involved selecting stents of the same size as the diameter of the target vessel and slowly inflating the balloon to its nominal pressure. One-year angiography and midterm clinical follow-up data were obtained. The stents were successfully placed in all patients without any perioperative complication. The mean preoperative stenosis rate of 81% decreased to 4% after the stent was placed. Nine patients who underwent follow-up angiography (one patient refused) at a mean of 12.3 months (range 10-19 months) had no changes in luminal diameter compared with the immediate postoperative luminal diameter. Luminal narrowing increased, from 15 to 38%, in one case in which there was comparatively greater residual stenosis (15%). No patient suffered new ischemic symptoms during a mean clinical follow-up period of 21 months (range 12-36 months).

CONCLUSIONS

Elective stent surgery can provide good angiographic and clinical midterm outcomes in patients with symptomatic intracranial atherosclerotic stenosis, and the procedure is associated with a high degree of technical success. Reassessment of these promising results is needed in a larger population and in a randomized prospective comparison study.

Early and intermediate-term outcomes with drug-eluting stents in high-risk patients with symptomatic intracranial stenosis

OBJECTIVE

To report the 1-month and intermediate-term results of treatment of symptomatic intracranial stenosis using drug-eluting stents.

BACKGROUND

Patients with intracranial stenosis who are at high risk because of either high-grade stenosis or medication failure may have an annual risk of recurrent ischemic events in excess of 40%. Drug-eluting stents may reduce the rate of ischemic events in patients with a low restenosis rate.

METHODS

We determined rates of technical success (defined as reduction of target lesion to stenosis <30%) and 1-month major stroke or death in patients with symptomatic intracranial stenosis (> or =70% and/or medication failure). Patients' clinical and follow-up information during a mean period of 14.3 +/- 7 months were obtained. Kaplan-Meier analysis was performed to determine the rate of major stroke-free survival during 12 months.

RESULTS

There were 18 patients (mean age, 58 +/- 16 yr; 12 were men) treated with either a sirolimus-eluting stent (n = 14) or a paclitaxel-eluting stent (n = 4) for stenosis located in the: intracranial internal carotid artery (n = 6), proximal middle cerebral artery (n = 4), intracranial vertebral artery (n = 4), vertebrobasilar junction (n = 2), or basilar artery (n = 2). There was one major stroke and no death observed in the 1-month follow-up. At the 6-month follow-up examination, no major stroke or death was observed. Major stroke-free survival was 86% (+/-standard error of 9%) at 12 months after the procedure. One symptomatic angiographic restenosis was observed during the follow-up period.

CONCLUSION

A low rate of major stroke or death was observed after treatment of symptomatic intracranial stenosis using drug-eluting stents in high-risk patients.

Angioplasty of an idiopathic intracranial arterial stenosis

Treatment of symptomatic intracranial atherosclerotic stenosis usually involves maximizing medical therapy. In patients with medically refractory symptoms despite maximum pharmacologic therapy, intracranial angioplasty and/or stenting has become an accepted treatment option. The use of percutaneous transluminal angioplasty (PTA) for idiopathic intracranial stenoses has not been reported to date.We describe a case of idiopathic intracranial stenosis which was refractory to medical therapy and was successfully treated with percutaneous transluminal angioplasty. The presenting symptoms included multiple episodes of aphasia and right-sided weakness as well as a left basal ganglia infarct. The patient underwent treatment with two intracranial angioplasty procedures. There was a recurrence of the stenosis and symptoms following the first procedure. However, after a second treatment with a slightly larger balloon, flow in the MCA normalized. Furthermore, the symptoms attributed to her MCA stenosis had essentially resolved. This case suggests that patients with medically refractory idiopathic intracranial stenosis can be successfully treated with percutaneous transluminal angioplasty.

Endovaskuläre Behandlung intrakranieller Stenosen

Intracranial stenoses cause 5-10% of all strokes and are increasingly detected by means of modern imaging methods. The stroke danger of high-grade symptomatic stenoses is relatively high, with an annual risk of approximately 10% under medical treatment. Coumadin increases the risk of hemorrhage, and after risk/benefit considerations, antiplatelets should be preferred for antithrombotic therapy. Despite optimized medical treatment, a small group of patients with recurrent symptoms or symptomatic stenoses without adequate collateral supply probably carry higher spontaneous stroke risk and may be considered for intracranial stenting, which itself is associated with procedural risks of up to 10%. Currently published case series show relatively high complication rates as a major drawback of endovascular treatment, mainly strokes after occlusion of perforating branches extending from the stenotic vessel segment or hemorrhagic complications. According to data from smaller feasibility studies, stroke rates in follow-up after successful stenting seem to be low. The average rate of high-grade restenosis with possible indication for reintervention is 10%. Improvements in endovascular treatment aim at reducing vessel wall trauma during balloon angioplasty by underdilatation or the use of self-expanding stents. Until complication rates are dependably reduced to values of 5-6%, indication for endovascular treatment should be restricted to patients without therapeutic alternatives. According to limited data with large variation between different studies, a prospective multicentric registry is proposed for systematic evaluation and further development of the method.

Management of symptomatic intracranial arterial stenosis: endovascular therapy

Patients with symptomatic intracranial stenosis are at high risk of subsequent stroke despite the use of antithrombotic agents or surgical management. Although endovascular therapy appears to promise therapeutic solutions, the reported high peri-procedural adverse event rate limits the widespread use of this technique. In the past few years, the morbidity and mortality associated with intracranial angioplasty and stenting have decreased with the development of new intracranial specific devices. The most recent prospective studies on intracranial stenting have been nothing more than registries of patients with symptomatic intracranial stenosis of 50% or greater who have failed medical therapy. However, no randomized controlled data exist on the comparison between endovascular therapy and medical treatment. There are new data identifying factors associated with a higher risk of stroke in medically treated patients. These findings will help to define a high-risk patient population on whom the initial controlled trials will be conducted.

Intracranial angioplasty and stenting for cerebrovascular disease

The use of stent-assisted techniques to manage a variety of cerebrovascular conditions has exploded in recent years. Although the safety of devices is expected to continue to improve, the absence of scientific validation remains an issue in many indications. In posterior circulation arterial disease, considering the absence of valid and reasonable surgical options and the results of the WASID trial, there is widespread consensus that endovascular therapy will become the main option. In anterior circulation intracranial disease, surgical revascularization (EC/IC bypass) may continue to remain an option in selected patients, although it is unclear whether or not randomized clinical trials would be either useful or feasible. The treatment of wide-necked intracranial aneurysms has benefited greatly from the advent of stenting. Intracranial arterial dissections are uncommon and life threatening enough for stenting to remain a major, if not the only, treatment option in many; flexible covered microstents may become the preferred treatment in arterial segments that do not harbor perforators. Concerning the endovascular management of pseudotumor cerebri, as more insight is gained into the epidemiology and the pathophysiology of the disease, it is likely that validation against conventional surgical shunt techniques will be required, at least in subgroups of patients. There is no doubt at this point that large numbers of patients will continue to benefit from the technique. A strong focus on patients' specific needs, a thorough multidisciplinary approach, and continuing efforts in research are necessary to help maintain procedural risks as low as possible.

Current Concepts in the Management of Intracranial Atherosclerotic Disease

MEDICALLY REFRACTORY, SYMPTOMATIC intracranial atherosclerotic disease has a poor prognosis. Based on the results of the Warfarin-Aspirin Symptomatic Intracranial Disease study, the risk of ipsilateral stroke at 1.8 years is between 13 and 14% in patients with symptomatic intracranial atherosclerosis. Synergistic advances in intracranial angioplasty and stenting, modern neuroimaging techniques, and periprocedural and postprocedural antithrombotic regimens are creating new models for the diagnosis and successful endovascular treatment of intracranial stenosis. In this article, the most recent clinical developments and concepts for the diagnosis and endovascular treatment of intracranial atherosclerotic disease are discussed.

Six-month follow-up study in patients with symptomatic intracranial arterial stenosis

Ischaemic stroke due to intracranial atherosclerosis is estimated to comprise 8-12% of all ischaemic strokes. It is known that the risk of recurrence is extremely high in patients with ischaemic stroke caused by intracranial stenosis. In the present study we aimed to evaluate the clinical and radiological findings over a 6-month follow-up period in patients with intracranial atherosclerosis. Prospective data for the ischaemic stroke patients admitted to our clinic between 2001 and 2004 were collected. The localization of stenosis/occlusion detected by magnetic resonance angiography (MRA) was recorded and patients were divided into two groups according to the presence of one or more arterial stenoses on MRA. The patients were followed up for 6 months at regular intervals and stroke recurrence and deaths were noted. Of the 47 patients, 11 had posterior circulation stenosis and 36 had anterior circulation stenosis. Thirty-three patients had only one intracranial artery stenosis, whereas 14 had more than one intracranial artery stenosis. Of the 38 patients who completed the 6-month follow-up period, 13 had recurrent stroke, and 10 died. The rate of stroke recurrence in patients with intracranial artery stenosis may be higher than in patients with stroke due to other aetiologies, and stenosis of multiple intracranial arteries increases the rate of recurrence.