Prospective study of symptomatic atherothrombotic intracranial stenoses: The GESICA Study

Differences in plaque morphology and correlation of stenosis at the carotid artery bifurcation and the carotid siphon

OBJECTIVE

The purpose of this study was to compare the type of plaque and the degree of stenosis in the carotid artery bifurcation and the carotid siphon to explore potential correlations between these parameters.

MATERIALS AND METHODS

A total of 119 patients (87 men, 32 women; mean age, 69 years) were retrospectively studied using MDCT angiography. Component types of the carotid artery bifurcation and the carotid siphon plaque were defined according to attenuation values, and the volumes of each plaque component were calculated. The degree of stenosis was calculated according to the North American Symptomatic Endarterectomy Trial method. Data were compared using the Wilcoxon signed-rank test, Spearman correlation analysis, and receiver operating characteristic (ROC) analysis.

RESULTS

The results of the Wilcoxon test showed a statistically significant difference (p = 0.0001) between the degree of stenosis at the carotid artery bifurcation and that at the carotid siphon. We observed a statistically significant difference (p = 0.0001) between the total volumes of the carotid artery bifurcation (mean value, 748 mm(3)) and the carotid siphon (mean value, 54 mm(3)) plaque. Moreover, the respective mean percentages of calcified, mixed, and lipid components of plaque were 17%, 56%, and 27% in the carotid artery bifurcation and 73%, 19%, and 8% in the carotid siphon, showing a statistically significant difference (p = 0.001). ROC analysis did not show association between carotid siphon plaque volume and previous cerebrovascular events (Az = 0.562; p = 0.149), whereas the total volume of the carotid artery bifurcation plaque--and, in particular, the volume of the lipid components--showed a statistically significant association (Az = 0.691, and Az = 0.758; p < 0.001).

CONCLUSION

No significant association was found between presence of mixed and fatty components of plaque in the carotid artery bifurcation and presence of similar components in the carotid siphon. The carotid artery bifurcation total plaque volume (and, in particular, carotid artery bifurcation lipid volume) was associated with previous cerebrovascular events, whereas no association with the volume of carotid siphon plaque (and its subcomponents) was found.

Extracranial-intracranial bypass for ischemic cerebrovascular disease: what have we learned from the Carotid Occlusion Surgery Study?

Extracranial-intracranial (EC-IC) arterial bypass has been used in the treatment of various neurosurgical pathologies including skull base tumors requiring sacrifice of a large intracranial artery; complex intracranial aneurysms requiring trapping; and distal revascularization, moyamoya disease, and symptomatic cerebrovascular stenoocclusive disease. The latter indication has been the subject of intense investigations in several large randomized controlled trials, most recently the Carotid Occlusion Surgery Study (COSS). In the present literature review and synthesis, the authors examine the current evidence available for EC-IC arterial bypass for the treatment of ischemic cerebrovascular disease including both extracranial carotid artery occlusive disease and intracranial atherosclerotic disease. They focus particular attention on EC-IC arterial bypass for the treatment of symptomatic hemodynamic cerebral ischemia and how lessons learned from the COSS might guide future investigations into the treatment of this disease.

Ultrasound-based imaging in neurocritical care patients: a review of clinical applications

OBJECTIVE

To analyze the diagnostic, monitoring, and procedural applications of ultrasound (US) imaging in neurocritical care (NCC) patients.

METHOD

US imaging has been extensively validated in various subset of critically ill patients, but not specifically in the NCC population. We reviewed the clinical applications of US imaging for heart, vascular, brain, and lung evaluation and for possible procedural uses in NCC patients. Major neurosurgical books, journals, testimonials, authors' personal experience, and scientific databases were analyzed.

RESULTS

Cardiac US imaging provides accurate information at NCC arrival to stratify risk factors, including presence of atrial septal defect/patent formen ovale, abnormal ventricular function, or pericardial effusion, and to monitor cardiac anatomy and function during the NCC stay for guiding goal-directed therapy. Vascular US in NCC patients has three especially relevant indications: to screen anatomy and flow in extracranial supra-aortic arteries, to diagnose deep vein thrombosis, and to optimize the safety of central venous catheterization. Brain US has important clinical applications in the NCC, including transcranial Doppler and emerging techniques for cerebral blood flow evaluation with contrast-enhanced US imaging. Lung US, as demonstrated in other intensive care unit patients, provides accurate diagnosis of anatomical and functional abnormalities and enables diagnosis of pleural effusion, pneumothorax, lung consolidation, pulmonary abscess and interstitial-alveolar syndrome, and lung recruitment/derecruitment. US imaging can effectively guide percutaneous tracheostomy.

CONCLUSION

In conclusion, US imaging is an important diagnostic tool that provides real-time information at the bedside to stratify risk, monitor for complications, and guide invasive procedures in NCC patients.

Higher numbers of circulating endothelial progenitor cells in stroke patients with intracranial arterial stenosis

Background

Bone marrow-derived endothelial stem cells participate in vascular repairs. Numbers of circulating endothelial progenitor cells (cEPCs) are associated with atherosclerosis. Fibrinogen plays a key role in atherosclerosis. Objective was to assess if cEPC counts were associated with atherosclerotic intracranial artery stenosis (IAS).

Methods

Three hundred subjects (108 patients with stroke and IAS (IAS), 120 control patients with stroke without IAS (CP), and 72 healthy controls (HC)) were retrospectively analyzed. cEPCs were identified and counted by flow cytometry using CD34, CD133 and KDR. Plasma fibrinogen was measured by immunoturbidimetry. cEPC counts were compared between the three groups.

Results

cEPC numbers were significantly higher in IAS (0.059 ± 0.031%) than in CP (0.026 ± 0.012%) (P < 0.001) and HC (0.021 ± 0.011%) (P < 0.001), but without difference between CP and HC (P = 0.401). Multiple logistic regression analysis showed that cEPC levels (OR 3.31, 95%CI 1.26-8.87, P = 0.025; IAS vs. CP) were independent markers of IAS after adjustment for hypertension, diabetes and smoking. No significant correlation between cEPC counts and plasma fibrinogen levels was observed (P > 0.05).

Conclusion

cEPC numbers were associated with degrees of IAS. This measurement may be useful for non-invasive evaluation of atherosclerotic IAS.

Endovascular treatment of intracranial atherosclerotic disease

Stroke is the third leading cause of death in the United States. Intracranial atherosclerotic disease plays a role in cerebrovascular accidents, with well-characterized modifiable and nonmodifiable risk factors. Surgical bypass has so far not proved to be superior to medical therapy. Both medical and endovascular therapies for intracranial atherosclerosis have evolved since the initial off-label use of cardiac devices for its treatment. Initial reports on the results of stent placement for symptomatic high-grade intracranial atherosclerotic disease were initially encouraging. However, debate remains as to the optimal treatment of symptomatic intracranial atherosclerotic disease.

Prevalence and long-term clinical significance of intracranial atherosclerosis after ischaemic stroke or transient ischaemic attack: a cohort study

OBJECTIVES

We investigated the prevalence and long-term risk associated with intracranial atherosclerosis identified during routine evaluation.

DESIGN

This study presents data from a prospective cohort of patients admitted to our stroke unit for thrombolysis evaluation.

SETTING AND PARTICIPANTS

We included 652 with a final diagnosis of ischaemic stroke or transient ischaemic attack (TIA) from April 2009 to December 2011. All patients were acutely evaluated with cerebral CT and CT angiography (CTA). Acute radiological examinations were screened for intracranial arterial stenosis (IAS) or intracranial arterial calcifications (IAC). Intracranial stenosis was grouped into 30-50%, 50-70% and >70% lumen reduction. The extent of IAC was graded as number of vessels affected.

PRIMARY AND SECONDARY OUTCOME MEASURE

Patients were followed until July 2013. Recurrence of an ischaemic event (stroke, ischaemic heart disease (IHD) and TIA) was documented through the national chart system. Poor outcome was defined as death or recurrence of ischaemic event.

RESULTS

101 (15.5%) patients showed IAS (70: 30-50%, 29: 50-70% and 16: >70%). Two-hundred and fifteen (33%) patients had no IAC, 339 (52%) in 1-2 vessels and 102 (16%) in >2 vessels. During follow-up, 53 strokes, 20 TIA and 14 IHD occurred, and 95 patients died. The risk of poor outcome was significantly different among different extents of IAS as well as IAC (log-rank test p<0.01 for both). In unadjusted analysis IAS and IAC predicted poor outcome and recurrent ischaemic event. When adjusted, IAS and IAC independently increased the risk of a recurrent ischaemic event (IAS: HR 1.67; CI 1.04 to 2.64 and IAC: HR 1.22; CI 1.02 to 1.47).

CONCLUSIONS

Intracranial atherosclerosis detected during acute evaluation predicts an increased risk of recurrent stroke.

Imaging and clinical predictors of unfavorable outcome in medically treated symptomatic intracranial atherosclerotic disease

BACKGROUND

Patients with symptomatic intracranial atherosclerotic disease (sICAD) have an increased risk of stroke and vascular death. The aim of the study was to evaluate the natural history and outcome of patients with sICAD treated medically.

METHODS

The study population was first-ever transient ischemic attack (TIA) or stroke patients presenting to our institute who on vascular imaging had isolated intracranial atherosclerosis as cause of their symptoms and have a follow-up of 90 days. Unfavorable outcome was defined as occurrence of TIA, stroke, acute coronary event, and/or vascular death.

RESULTS

Fifty-three (11.8%) of the 449 ischemic stroke patients had sICAD. The risk of stroke in sICAD was 8.9%, 11.1%, 13.3%, and 15.6% in first 7 days, 30 days, 90 days, and 1 year, respectively. Five (11.1%) had cardiovascular events and accounted for 50% of mortality. The predictors of unfavorable outcome were presented as limb weakness (85.7% versus 58.8%, hazard ratio 1.5; 95% confidence interval [CI], .05-.9; P = .04), National Institutes of Health Stroke Scale (NIHSS) score 8 at admission (50% versus 5.9%, hazard ratio 8.5; 95% CI, .007-.5; P = .02), magnetic resonance imaging (MRI) with multiple diffusion-weighted imaging (DWI) lesions (65.4% versus 26.7%; 95% CI, .04-.7; P = .01), and angiography suggestive of diffuse atherosclerosis (50% versus 11.8%; 95% CI, odds ratio .02-.7; P = .009). On stepwise multiple regression, variables for unfavorable outcome were NIHSS score of 8 or more at admission (P = .001), multiple DWI lesion on MRI (P = .04), and diffuse atherosclerosis on angiography (P = .006).

CONCLUSION

The patients with sICAD have a high risk of stroke and cardiac events even on aggressive medical treatment. Clinical and imaging features can identify this high-risk group.

Functional imaging of cerebral perfusion

The functional imaging of perfusion enables the study of its properties such as the vasoreactivity to circulating gases, the autoregulation and the neurovascular coupling. Downstream from arterial stenosis, this imaging can estimate the vascular reserve and the risk of ischemia in order to adapt the therapeutic strategy. This method reveals the hemodynamic disorders in patients suffering from Alzheimer's disease or with arteriovenous malformations revealed by epilepsy. Functional MRI of the vasoreactivity also helps to better interpret the functional MRI activation in practice and in clinical research.

Higher risk of recurrent ischemic events in patients with intracranial in-stent restenosis

BACKGROUND AND PURPOSE

Reliable data concerning prognosis of patients with intracranial in-stent restenosis (ISR) is lacking. We prospectively studied long-term outcomes of patients with and without a catheter angiography-verified ISR.

METHODS

Between September 2001 and May 2009, 540 consecutive patients with symptomatic intracranial atherosclerosis received stenting treatment at our institute. Of them, 226 patients with 233 stented arteries had catheter angiography follow-up after stenting and were enrolled into this study. They were clinically followed up until the end of December 2011. Primary end point was ischemic stroke or transient ischemic attack in the territory of the stented artery after the catheter angiography follow-up. ISR was defined as a catheter angiography-verified stenosis of ≥50% within or immediately adjacent (within range of 3 mm) to the implanted stent.

RESULTS

During a mean follow-up of 38.9 months, 27 (11.6%, 27/233) primary end point events were recorded. The risk of primary end point in ISR group was higher compared with non-ISR group (21.1% [12/57] versus 8.5% [15/176]; hazard ratio, 2.94; 95% confidence interval, 1.37-6.30; P=0.005). Multivariable analysis showed that the ISR was an independent risk factor for the primary end point (hazard ratio, 2.79; 95% confidence interval, 1.20-6.49; P=0.017). The median occurrence time of primary end point was 9.9 (interquartile range, 5.0, 21.1) months in ISR group, earlier than that in non-ISR group (26.6 [13.1, 52.9] months; P=0.01).

CONCLUSIONS

In-stent restenosis after stenting of intracranial atherosclerosis is significantly associated with an increased risk and an earlier occurrence of recurrent ischemic events in the territory of the stented intracranial artery.

Calcifications of vertebrobasilar arteries on CT: detailed distribution and relation to risk factors in 245 ischemic stroke patients

INTRODUCTION

Intracranial atherosclerosis is responsible for a substantial proportion of strokes worldwide but its detailed morphology in the vertebrobasilar arteries (VBA) is unknown.

SUBJECT AND METHODS

Cases with ischemic strokes were retrospectively sought from the hospital database. Native CT scans were assessed for vessel area and intracranial artery calcifications (ICACs) in VBA. The calcifications were classified as focal (FCs), crescent, and circular.

RESULTS

245 patients (mean age: 77.1 ± 10.2 years, 57.6% females) had visible ICACs. Calcifications were found in 75.9%, 63.3%, and 17.1% in the left vertebral artery (LVA), the right vertebral artery (RVA), and the basilar artery (BA), respectively. FCs were present in 91.0%, 90.3%, and 100.0%; crescents in 30.3%, 29.0%, and 7.1%, and circulars in 6.4%, 4.8%, and 0.0% ) and 46 (27.4%) for RVA and LVA, respectively. Risk factors associated with vertical dispersion of ICACs were male gender (OR : 2.69, 1.38-5.28) and diabetes of the RVA, LVA, and BA, respectively. FCs in dorsolateral quadrant were least prevalent in both vertebral arteries (VAs): 46 (29.8%(OR : 2.28, 1.04-4.99).

CONCLUSIONS

FCs in VAs are least prevalent in dorsolateral quadrants. The vertical dispersion of ICACs seems to be associated with the male gender and diabetes.

Comprehensive gene expression profiling reveals synergistic functional networks in cerebral vessels after hypertension or hypercholesterolemia

Atherosclerotic stenosis of cerebral arteries or intracranial large artery disease (ICLAD) is a major cause of stroke especially in Asians, Hispanics and Africans, but relatively little is known about gene expression changes in vessels at risk. This study compares comprehensive gene expression profiles in the middle cerebral artery (MCA) of New Zealand White rabbits exposed to two stroke risk factors i.e. hypertension and/or hypercholesterolemia, by the 2-Kidney-1-Clip method, or dietary supplementation with cholesterol. Microarray and Ingenuity Pathway Analyses of the MCA of the hypertensive rabbits showed up-regulated genes in networks containing the node molecules: UBC (ubiquitin), P38 MAPK, ERK, NFkB, SERPINB2, MMP1 and APP (amyloid precursor protein); and down-regulated genes related to MAPK, ERK 1/2, Akt, 26 s proteasome, histone H3 and UBC. The MCA of hypercholesterolemic rabbits showed differentially expressed genes that are surprisingly, linked to almost the same node molecules as the hypertensive rabbits, despite a relatively low percentage of ‘common genes’ (21 and 7%) between the two conditions. Up-regulated common genes were related to: UBC, SERPINB2, TNF, HNF4A (hepatocyte nuclear factor 4A) and APP, and down-regulated genes, related to UBC. Increased HNF4A message and protein were verified in the aorta. Together, these findings reveal similar nodal molecules and gene pathways in cerebral vessels affected by hypertension or hypercholesterolemia, which could be a basis for synergistic action of risk factors in the pathogenesis of ICLAD.

Combination aspirin and clopidogrel for secondary prevention of ischemic stroke

OPINION STATEMENT

Though antiplatelet agents are the mainstay of antithrombotic therapy for secondary prevention of noncardioembolic cerebral ischemic events, the efficacy of combination aspirin and clopidogrel has yet to be clarified by clinical trials. Current evidence suggests that there is no role for long-term combination of aspirin/clopidogrel for secondary stroke prevention. Recent preliminary data from the CHANCE (Clopidogrel in High-risk Patients with Acute Non-disabling Cerebrovascular Events) trial suggests that stroke recurrence at 90 days is reduced by a short course (21 days) of combination aspirin/clopidogrel initiated within 24 hours of minor stroke or TIA (Transient Ischemic Attack) compared with aspirin alone [1••] (Table 1). Other ongoing trials, which are also investigating the role of short-term combination antiplatelet therapy initiated immediately after minor stroke and TIA, will determine if these findings will be replicated.

Advances in imaging of intracranial atherosclerotic disease and implications for treatment

OPINION STATEMENT

Intracranial atherosclerotic disease (ICAD) is one of the most common causes of ischemic stroke worldwide and is associated with a high risk of recurrent stroke despite aggressive therapy. ICAD may lead to cerebral ischemia through a variety of mechanisms, the interactions of which are largely unknown. The use of endovascular therapy for the prevention of stroke related to severe ICAD has been studied but was associated with a higher risk of recurrent stroke and death in the Stenting and Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis (SAMMPRIS) study. With advances in diagnostic testing, it may be possible to better delineate the specific mechanism of stroke from ICAD and identify those patients at higher risk for recurrent ischemia. There may be a subset of patients less responsive to medical interventions, such as those with hemodynamic failure as opposed to those with perforator syndromes, who would benefit from medical plaque stabilization or safer endovascular approaches such as angioplasty alone. These will need to be tested in future clinical trials. Overall, symptomatic ICAD remains a high risk condition with suboptimal treatment options.

Burden of intracranial steno-occlusive lesions on initial computed tomography angiography predicts poor outcome in patients with acute stroke

BACKGROUND AND PURPOSE

Computed tomography angiography is an accurate noninvasive method to diagnose intracranial steno-occlusive disease (ICAD) at initial presentation for stroke. We aimed to identify features of computed tomography angiography associated with unfavorable outcome.

METHODS

We identified patients with ICAD in the Screening Technology and Outcomes Project in Stroke Study, a prospective imaging-based study of stroke outcomes, in consecutive patients with ischemic stroke or transient ischemic attack (TIA) presenting to 2 academic medical centers. All patients underwent computed tomography angiography, which were graded by 2 neuroradiologists independently. Univariate and multiple logistic regression was used to evaluate predictors of favorable outcome at 6 months, defined as a modified Rankin Scale ≤ 2.

RESULTS

Among 539 patients that met study entry criteria, ICAD was identified in 212 patients (39%); 116 patients (22%) had concurrent extraintracranial lesions, and 66 patients (12%) had multiple sites of ICAD. Patients with ICAD had more severe stroke (median National Institutes of Health Stroke Scale, 9 versus 3; P<0.001), worse outcomes at 6 months (modified Rankin Scale, 0-2; 57% versus 73%; P<0.001), and higher mortality (18% versus 8%; P=0.001). In the multivariate model, age (odds ratio [OR], 0.75 per decade; 95% confidence interval [CI], 0.65-0.87), female sex (OR, 0.49; 95% CI, 0.32-0.73), multiple sites of ICAD (OR, 0.53; 95% CI, 0.29-0.97), complete occlusion (OR, 0.42; 95% CI, 0.25-0.72), and concurrent extraintracranial lesions (OR, 0.51; 95% CI, 0.31-0.84) negatively predicted favorable outcome.

CONCLUSIONS

Findings of multiple sites of ICAD from computed tomography angiography, concurrent extraintracranial lesions, and complete occlusion are independent predictors of unfavorable outcome at 6 months.

Chronic hemodynamic compromise and cerebral ischemic events in asymptomatic or remote symptomatic large-artery intracranial occlusive disease

BACKGROUND AND PURPOSE

In asymptomatic or remote symptomatic LAICOD, the risk of ischemic events is low in general, but there may be a subgroup of higher risk patients who require aggressive medical management. The purpose of this study was to determine whether chronic hemodynamic compromise is a predictor of ischemic events in asymptomatic or remote symptomatic LAICOD.

MATERIALS AND METHODS

We prospectively studied 51 asymptomatic, 19 coexistent asymptomatic, and 19 remote (>6 months) symptomatic patients with atherosclerotic intracranial internal carotid artery or middle cerebral artery disease by using (15)O-PET. MP was defined as decreased CBF, increased OEF, and a decreased CBF/CBV ratio. All patients were followed up for 2 years or until occurrence of stroke or TIA or death.

RESULTS

Bypass surgery was performed in 4 patients (2 with MP). Three cerebral ischemic events (1 TIA in an asymptomatic patient, 1 stroke, and 1 TIA in a remote symptomatic patient) occurred in the vascular territory ipsilateral to LAICOD. Kaplan-Meier analysis with censoring at the time of bypass surgery revealed that the incidence of ipsilateral ischemic events in patients with MP (2/5) was significantly higher than that in patients without MP (1/84) (log-rank test; P < .0001). The relative risk conferred by MP was 83.1 (95% confidence interval, 6.8-1017.4; P < .001). The incidence of ipsilateral ischemic events in patients with decreased CBF/CBV (2/9) was also significantly higher than that of patients without it (1/80) (P = .0001).

CONCLUSIONS

Chronic hemodynamic compromise may be a predictor of ischemic events in both asymptomatic and remote symptomatic LAICOD.

Normalization of cerebral vasoreactivity using BOLD MRI after intravascular stenting

BACKGROUND AND PURPOSE

Intravascular angioplasty and stenting of intracranial arterial stenosis provided controversial results. Besides the expertise of the practitioners, the selection of the patients remains challenging. BOLD MRI of the cerebral vasoreactivity (BOLD MRI CVR) to hypercapnia provides reproducible maps of the entire brain of the vascular reserve, and could be helpful to assess the best therapeutic strategy.

CASE HISTORY

We report the case of a 63-year-old woman referred for a severe stenosis of the proximal portion of the left middle cerebral artery, revealed by a lenticulostriate and precentral infarction. Despite an aggressive medical treatment during 5 months, the occurrence of iterative transient ischemic attacks motivated intravascular stenting. Functional MRI of the vasoreactivity to hypercapnia using both Blood Oxygen Level Dependent (BOLD) and arterial spin labeling sequences showed normal basal perfusion and impaired vasoreactivity in the left middle cerebral artery territory. Three months after stenting, the BOLD MRI CVR showed vasoreactivity normalization. Since, the patient remains free of ischemic disorders one year after stenting.

CONCLUSION

BOLD MRI of the CVR to hypercapnia may be helpful to optimize the treatment of patients with intracranial arterial stenosis, and could be performed in future therapeutic trials.

Effect of statin on progression of symptomatic intracranial atherosclerosis

BACKGROUND

Symptomatic intracranial atherosclerosis (ICAS) is a dynamic disease that frequently progresses. Statins have been shown to have anti-atherosclerotic activity. We therefore investigated whether statins could prevent progression of ICAS.

METHODS

This retrospective cohort study assessed 55 patients with acute ischemic stroke and symptomatic ICAS in the middle cerebral or basilar arteries as shown on magnetic resonance angiography (MRA), with follow-up MRA performed more than 1 year after the index stroke. Change in ICAS was classified as progressive, regressive, or stable. Baseline clinical characteristics and risk factor control during follow-up were assessed, and laboratory tests were performed at the time of follow-up MRA. The statin group was defined as patients regularly treated with statins for more than 75% of the follow-up period; the remaining patients were defined as the non-statin group.

RESULTS

At a median follow-up time of 21.8 months (range, 11.8-66.1 months), the statin group consisted of 26 (47.3%) patients and the non-statin group of 29 (52.7%). During follow-up, 6 (10.9%) patients progressed, 14 (25.5%) regressed, and 35 (63.6%) remained stable. Statin treatment was significantly associated with non-progression of ICAS (p=0.024). Two patients in the non-statin group had recurrent strokes. Border-zone infarcts were associated with progression of ICAS (3/6, 50%; p=0.007), whereas risk factors and inflammatory biomarkers were not related to progression.

CONCLUSIONS

Treatment with statins may prevent progression of symptomatic ICAS. Prospective randomized controlled trials are required to confirm that statins protect against such progression.

Wingspan Stenting for Intracranial Atherosclerotic Stenosis

BACKGROUND:

Intracranial atherosclerotic stenosis (ICAS) is responsible for 9% to 37% of ischemic strokes.

OBJECTIVE:

To evaluate the clinical outcome and risk factors for in-stent restenosis (ISR) after treatment of ICAS with a Wingspan stent.

METHODS:

Seventy-seven patients with 79 total target ICAS &gt; 60% (mean, 79.9 ± 8.4%; symptomatic ICAS, 96.2%) underwent attempted treatment with Wingspan stenting between March 2010 and March 2011. A retrospective review of the prospectively registered data was conducted to assess the risk factors for ISR and the clinical outcomes of these patients.

RESULTS:

The 30-day transient ischemic attack/stroke and death rates were 5.3% (95% confidence interval [CI], 0.1-10.5) and 0%, respectively. All patients but 1 were followed up clinically for a mean of 18.9 months (range, 12–23 months). During the period, cumulative transient ischemic attack/stroke and death rates were 8.1% (95% CI, 1.7-14.5) and 0%, respectively. Only 1 patient suffered a disabling stroke (subarachnoid hemorrhage), which was associated with retreatment of an ISR with a drug-eluting balloon-expandable stent. Follow-up angiography was available in 69 treated vessels (89.6%) at 3 to 24 months (median, 12 months). Binary ISR rate was 24.6%, of which 17.6% (3 of 17 cases) was symptomatic. Rapid balloon inflation (95% CI, 5.490-530.817) and longer length of stenosis (95% CI, 1.093-1.891) were independent risk factors for ISR.

CONCLUSION:

Wingspan stenting may be effective for appropriately selected ICAS patients. Rapid balloon inflation and longer lengths of stenosis were independent risk factors for ISR.

Impact of metabolic syndrome on the prognosis of ischemic stroke secondary to symptomatic intracranial atherosclerosis in Chinese patients

OBJECTIVES

To analyze the effect of metabolic syndrome (MetS) on prognosis of ischemic stroke secondary to intracranial stenosis in Chinese patients.

METHODS

A prospective cohort of 701 patients with ischemic stroke, caused by intracranial stenosis, were followed at 3-month intervals for 1 year to monitor development of recurrent stroke or death. Imaging was performed using magnetic resonance angiography. MetS was defined using International Diabetes Federation (IDF) criteria.

RESULTS

MetS was identified in 26.0% of the cohort of stroke patients. Patients with MetS were more likely to be female, nonsmokers, and more likely to have a prior history of diabetes mellitus, high blood glucose and a family history of stroke than patients without MetS. During 1-year follow-up, patients with MetS had a non-significantly higher rate of stroke recurrence (7.1%) than patients without MetS (3.9%; P = 0.07). There was no difference in mortality (3.3% versus 3.5%, respectively). Multivariate Cox proportional hazards analysis (adjusting for gender, BMI, smoking, diabetes, and LDL-C) identified an association between that 1-year stroke recurrence and the presence of MetS (hazard ratio 2.30; 95% CI: 1.01-5.22) and large waist circumference (hazard ratio: 2.39; 95% CI: 1.05-5.42). However, multivariable analysis adjusting for the individual components of MetS found no significant associations between MetS and stroke recurrence. There were no associations between these parameters and mortality.

CONCLUSIONS

Chinese patients with symptomatic intracranial atherosclerosis who have MetS, are at higher risk of recurrent stroke than those without MetS. However, MetS was not predictive of stroke recurrence beyond its individual components and one-year mortality.

Endovascular treatment of symptomatic intracranial atheromatous stenosis: a single center study of 21 consecutive cases

OBJECTIVES

This retrospective single-center study evaluated the technical success as well as the periprocedural and long-term complications of angioplasty with stenting of symptomatic intracranial atheromatous stenosis.

PATIENTS AND METHODS

From January 2005 to December 2010, 21 patients were treated by angioplasty with stent implantation for symptomatic atheromatous intracranial stenosis greater or equal to 50% at least 7 days after a stroke.

RESULTS

The median population age was 65 years (range: 41-88 years), and 76% (16/21) of the candidates had a history of transient ischemic attack (TIA) or stroke before the event qualifying them for an endovascular procedure. In addition, 86% (18/21) were taking antithrombotic medication at the time of the qualifying event. Technical success was obtained in all cases. The periprocedural stroke or death rate was 9.5% (2/21), and there was no other stroke or death after 30 days during the mean follow-up of 1.4 years.

CONCLUSION

Endovascular treatment of symptomatic intracranial atherothrombotic stenosis can lead to severe complications, particularly during the periprocedural period, but it also represents the only alternative treatment for patients who fail with medical therapy. Future studies need to focus on improvement of periprocedural complications. Essentially, this should include more rigorous selection of candidates as well as a better understanding of the pathophysiological mechanism(s) of the ischemic phenomenon related to stenosis.

Predictors of Recurrent Stroke in Patients With Symptomatic Intracranial Arterial Stenosis

Background and Purpose—

Our goal was to investigate whether initial ischemic lesion pattern can predict stroke recurrence in patients with symptomatic intracranial arterial stenosis.

Methods—

Of the Trial of Cilostazol in Symptomatic Intracranial Arterial Stenosis (TOSS)-2 trial participants, we included patients who underwent diffusion-weighted imaging and fluid attenuation inversion recovery imaging at baseline with a follow-up fluid attenuation inversion recovery imaging at 7 months. Based on the diffusion-weighted imaging findings, we classified the initial ischemic lesion patterns according to location (subcortical versus cortical versus subcorticocortical) and multiplicity (single versus multiple). We also evaluated the occurrence of new ischemic lesions on follow-up fluid attenuation inversion recovery as well as clinical stroke in the symptomatic intracranial arterial stenosis territory.

Results—

Of 353 patients included in this study, 44 (12.5%) and 13 (3.7%) patients had new ischemic lesions and clinical recurrent stroke in the initial symptomatic intracranial arterial stenosis territory, respectively. On multivariable analysis, the initial lesion patterns of subcorticocortical and multiple lesions were independent predictors of new ischemic lesions in the symptomatic intracranial arterial stenosis territory (OR, 3.01; 95% CI, 1.33–7.01; P =0.03; OR, 2.81; 95% CI, 1.34–5.9; P =0.006). These patterns also predicted clinical recurrent stroke.

Conclusion—

Subcorticocortical lesions and multiple lesions are radiological predictors of recurrent ischemic stroke in symptomatic patients with intracranial arterial stenosis.

Clinical Trial Registration—

URL: www.clinicaltrials.gov . Unique identifier: NCT00130039.

Symptomatic intracranial arterial disease: incidence, natural history, diagnosis, and management

Symptomatic intracranial arterial disease is associated with a high rate of recurrent ischemic events. The management of this condition is controversial, with some advocating medical therapy as a sole means of treatment and others recommending endovascular therapy in addition to best medical management. In rare cases, surgical intervention is considered. A thorough review of the available literature was performed, and treatment recommendations based on these data are provided.

Angioplasty with stenting for intracranial atherosclerosis: a systematic review

OBJECTIVE

Intracranial artery stenosis can be fatal, requiring fast, safe and effective intervention. The introduction of the Wingspan™ stent system with Gateway™ percutaneous transluminal angioplasty balloon catheter has made intracranial intervention possible in a clinical trial setting. This systematic review planned to identify and review all randomized controlled trials comparing angioplasty and stenting of intracranial arteries with standard medical care.

METHODS

Electronic databases and relevant records were examined for possible trials using predefined inclusion and exclusion criteria.

RESULTS

A total of 3661 records were identified by searching several English language databases and other sources including Chinese academic journals. The recently discontinued Stenting and Aggressive Medical Management for Preventing Recurrent stroke in Intracranial Stenosis (SAMMPRIS) trial was the single qualifying study and showed clear advantage of medical management over percutaneous transluminal angioplasty and stenting (PTAS).

CONCLUSIONS

The SAMPRASS trial indicated that PTAS is associated with high complication and morbidity rates. Definitive recommendations cannot be made until convincing results from additional robustly designed randomized trials become available.

Usefulness of stent implantation for treatment of intracranial atherosclerotic stenoses

Purpose

We evaluated the usefulness of intracranial stent implantation for treating patients with atherosclerotic stenosis and with recurrent, ischemic, neurological symptoms despite having undergone medical therapy.

Materials and Methods

Between March 2004 and April 2010, we attempted intracranial, stent-assisted angioplasty in 77 patients with 85 lesions (anterior circulation 73 cases, posterior circulation 12 cases) and who had ischemic neurological symptoms with more than 50% major cerebral artery stenosis. We analyzed the results regarding the technical success rate, complication rate, and restenosis rate during the mean 29.4 month follow-up period.

Results

Intracranial stent implantation was successfully performed in 74 cases (87.1%). In nine cases among the 11, failed cases, stent implantation failure was due to the tortuosity of the target vessel. One patient experienced middle cerebral artery rupture during the procedure, and we embolized the vessel using a microcoil. Five patients developed cerebral infarction in three weeks after the procedure, three of whom improved using conservative management, although the other, two patients expired. The mean number of residual stenoses decreased from 72.3% to 14.7%. Three patients demonstrated significant in-stent restenosis, i.e. more than 50%, during the follow-up period.

Conclusion

As stent-assisted angioplasty in intracranial, atherosclerotic stenosis is effective and relatively safe, it can be considered as an alternative treatment for patients with recurrent, ischemic, neurologic symptoms despite having undergone medical therapy.

Rate of Postprocedural Stroke and Death in SAMMPRIS Trial–Eligible Patients Treated With Intracranial Angioplasty and/or Stent Placement in Practice

BACKGROUND:

The SAMMPRIS (Stenting vs Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis) trial, comparing aggressive medical vs stent treatment in patients with symptomatic intracranial stenosis, was halted after a 14% stroke and death rate was observed in the stent-treated group.

OBJECTIVE:

To study the 30-day stroke and death rate in intracranial angioplasty- and stent-treated patients meeting SAMMPRIS trial eligibility criteria.

METHODS:

A retrospective analysis of 96 patients treated with intracranial angioplasty and stent placement at 3 university-affiliated institutions was performed. Patients were divided into SAMMPRIS trial eligible and ineligible groups based on inclusion and exclusion criteria for the SAMMPRIS trial.

RESULTS:

Sixty-nine patients were determined to be SAMMPRIS eligible and 27 patients were ineligible. The SAMMPRIS-eligible group was divided into angioplasty- and stent-treated subgroups (30 and 39 patients, respectively). The overall 30-day postprocedure stroke and death rate was 7.2% in the SAMMPRIS-eligible group and 7.4% in the SAMMPRIS-ineligible group (P = .97). The 30-day postprocedure stroke and death rate was 3.3% in the SAMMPRIS-eligible, angioplasty-treated subgroup and 10.2% in the SAMMPRIS-eligible, stent-treated subgroup (P = .27).

CONCLUSION:

The overall 30-day postprocedure stroke and death rate in our study was lower in both SAMMPRIS-eligible and -ineligible groups than the reported 14% stroke and death rate in the SAMMPRIS trial. We hypothesize that a more judicious use of primary angioplasty may be responsible for better postprocedure outcomes and should be considered an acceptable treatment in future trials.

[Endovascular treatment of symptomatic intracranial stenoses: short- and long-term results in a single center]

OBJECTIVES

We present the short- and long-term results of a series of patients with symptomatic intracranial arterial stenoses treated with angioplasty and stenting.

MATERIAL AND METHODS

We reviewed patients with symptomatic intracranial stenoses greater than 50% who were treated with angioplasty, stenting, or both. We recorded demographic data and risk factors (hypertension, diabetes, dyslipemia, ischemic heart disease). We classified all lesions treated according to their location, degree of stenosis, and length. The degree of stenosis was classified as moderate (50%-70%) or severe (>70%). In the follow-up, we assessed cerebrovascular accidents, episodes of ischemic heart disease, and deaths in the first 30 days and in later follow-up.

RESULTS

Between 2006 and 2010, we treated 26 patients (21 men and 5 women; age range, 44-79 years; mean age, 63 years) with 29 intracranial lesions. The endovascular procedure (angioplasty+stenting) was successfully performed in 23 cases (92.0%). In the first 30 days after the procedure, 3 (11.5%) patients had adverse effects of vascular origin: 1 stroke, 1 hemorrhage, and 1 death due to thrombosis of the stent. Long-term follow-up (5-46 months) in the 25 patients who survived more than 30 days detected no recurrence of symptoms.

CONCLUSION

Endovascular treatment of intracranial stenosis is technically feasible. Short-term complications are highly prevalent. No recurrence of symptoms was detected during long-term follow-up.

Low-Molecular-Weight Heparin Versus Aspirin for Acute Ischemic Stroke With Large Artery Occlusive Disease

Background and Purpose—

The Fraxiparin in Stroke Study for the treatment of ischemic stroke (FISS-tris) study showed no superiority of low-molecular-weight heparin (LMWH) over aspirin for the primary end point (Barthel Index) in acute ischemic stroke due to large artery occlusive disease. This study aims to evaluate the efficacy of LMWH and aspirin in selected subgroups so as to generate hypotheses for further studies.

Methods—

The FISS-tris study was a multicenter, randomized trial to investigate the efficacy and safety of LMWH (nadroparin calcium 3800 antifactor Xa IU/0.4 mL subcutaneously twice daily) or aspirin (160 mg once daily) for the treatment of patients with acute ischemic stroke and large artery occlusive disease. The primary outcome was the Barthel Index score dichotomized at 85 6 months poststroke. Exploratory subgroup analysis was performed using different levels of baseline characteristics and the distribution of symptomatic arteries.

Results—

Compared with aspirin, LMWH improved outcome among older patients >68 years ( P =0.043; OR, 1.86; 95% CI, 1.02–3.41) without ongoing antiplatelet treatment on admission ( P =0.029; OR, 1.85; 95% CI, 1.06–3.21) and with symptomatic posterior circulation arterial disease ( P =0.001; OR, 5.76; 95% CI, 2.00–16.56).

Conclusions—

Our findings suggest that LMWH may be of benefit in certain subgroups of patients with acute cerebral infarct and large artery occlusive disease. Hence, further investigation of LMWH may be justified in subgroups such as the elderly, nonusers of antiplatelet agents, and patients with posterior circulation stenosis.

Clinical Trial Registration—

URL: www.strokecenter.org/trials . Unique identifier: registration no. 493.

Comparison of NASCET and WASID criteria for the measurement of intracranial stenosis using digital subtraction and computed tomography angiography of the middle cerebral artery

BACKGROUND AND PURPOSE

Intracranial large-artery atherosclerosis is considered a frequent cause of stroke worldwide, particularly in Asian populations. The current evidence suggests that symptomatic patients with severe stenosis may benefit from intracranial stents. There are two methods for calculating the degree of intracranial stenosis, Warfarin-Aspirin Symptomatic Intracranial Disease (WASID) and North American Symptomatic Carotid Endarterectomy Trial (NASCET), but they have never been compared.

METHODS

A total of 25 patients with suspected middle cerebral artery (MCA) stenosis based on their acute presentation were imaged by computed tomography angiography (CTA), then confirmed by digital subtraction angiography (DSA). Measurements were carried out on symptomatic MCA using both methods for determining the degree of stenosis.

RESULTS

The degree of stenosis was significantly different using NASCET and WASID methods in DSA (48.2% vs. 54.6%; P<0.01), whereas CTA values did not differ significantly (54.2% vs. 52.0%; P = 0.9). All measurements were highly correlated between methods (Spearman r = 0.92 and 0.89, respectively; P<0.01).

CONCLUSION

The results of this study suggest that NASCET and WASID measures are, on average, generally similar, although substantial disagreement in a given patient may be seen.

Current management of symptomatic intracranial stenosis

Intracranial arterial stenosis (IAS) is the cause of about 10% of all ischemic strokes in the United States, but may account for about 40% of strokes in some populations. After a stroke or transient ischemic attack due to IAS, patients face a 12% annual risk of recurrent stroke on medical therapy, with most strokes occurring in the first year. Warfarin is no better than aspirin in preventing recurrent strokes but poses a higher risk of serious bleeding and death. Groups with the highest risk of recurrent stroke are those with high-grade (≥ 70%) stenosis, those with recent symptom onset, those with symptoms precipitated by hemodynamic maneuvers, and women. Endovascular treatment of IAS is a rapidly evolving therapeutic option. Antiplatelet agents are currently recommended as the primary treatment for symptomatic IAS, with endovascular therapy reserved for appropriate high-risk cases refractory to medical therapy.

Urgent recanalization with stenting for severe intracranial atherosclerosis after transient ischemic attack or minor stroke

OBJECTIVE

Stenting of symptomatic intracranial stenosis has recently become an alternative treatment modality. However, urgent intracranial stenting in patients with intracranial stenosis following a transient ischemic attack (TIA) or minor stroke is open to dispute. We sought to assess the feasibility, safety, and effectiveness of urgent intracranial stenting for severe stenosis (>70%) in TIA or minor stroke patients.

METHODS

Between June 2009 and October 2010, stent-assisted angioplasty by using a balloon-expandable coronary stent for intracranial severe stenosis (>70%) was performed in 7 patients after TIA and 5 patients after minor stroke (14 stenotic lesions). Technical success rates, complications, angiographic findings, and clinical outcomes were retrospectively analyzed.

RESULTS

Stenting was successful in all 12 patients. The mean time from symptom onset to stenting was 2.1 days (1-8 days). Post-procedural angiography showed restoration to a normal luminal diameter in all patients. In-stent thrombosis occurred in one patient (n=1, 8.3%), and was lysed with abciximab. No device-related complications, such as perforations or dissections at the target arteries or intracranial hemorrhaging, occurred in any patient. The mortality rate was 0%. No patient had an ischemic event over the mean follow-up period of 12.5 months (range, 7-21 months), and follow-up angiography (n=7) revealed no significant in-stent restenosis (>50%).

CONCLUSION

Urgent recanalization with stenting is feasible, safe, and effective in patients with TIA or acute minor stroke with intracranial stenosis of ≥70%.

Schlaganfallprävention: intrakranielle arterielle Stenosen

Intrakranielle arterielle Stenosen (IAS) sind für etwa 6,5–8% aller ischämischen Schlaganfälle verantwortlich. Für Patienten mit einer symptomatischen IAS wurde bislang trotz medikamentöser Sekundärprophylaxe innerhalb eines Jahres ein hohes Reinsultrisiko bis zu 12% in dem zugehörigen Gefäßterritorium beschrieben. Dabei haben IAS mit einem Stenosegrad ≥ 70% das höchste Reinsultrisiko (18%). Die Warfarin vs. Aspirin for Symptomatic Intracranial Stenosis Studie (WASID) führte zu der Empfehlung, dass bei symptomatischen IAS zunächst eine medikamentöse Sekundärprophylaxe mit Azetylsalizylsäure erfolgen sollte. Bei einem unter Thrombozytenfunktionshemmern auftretenden erneuten ischämischen Schlaganfall/TIA im Gefäßterritorium der symptomatischen IAS kann insbesondere bei Stenosen ≥ 70% eine interventionelle (stentgestützte) Angioplastie in einem spezialisierten Zentrum empfohlen werden. Zahlreiche aktuelle Veröffentlichungen legten nahe, dass durch die zunehmende Erfahrung der interventionell tätigen Neuroradiologen die periprozedurale Komplikationsrate zwischen 6 und 7% liegt, das Reinfraktrisiko bei bis zu 7,8% bei IAS > 70% liegen. Allerdings zeigte eine neue randomisierte Studie (SAMMPRIS), die bei symptomatischen IAS eine aggressive medikamentöse Sekundärprophylaxe mit der interven­tionellen Therapie vergliechen hat, dass in dieser Kohorte die Letalität im interventionellen Arm bei 14% lag, im medikamentösen Arm nur bei 5,8%. Eine abschließende Bewertung dieser noch sehr neuen Daten kann aktuell noch nicht erfolgen; ein Zwischenfazit könnte sein, dass eine endovaskuläre Therapie an speziellen Zentren in Betracht gezogen werden sollte wenn Patienten unter doppelter Thrombozytenfunktionshemmung weiterhin symptomatisch sind. Die Leitlinien werden sicher eine Weiterentwicklung und erneute Diskussion erfahren.

The prognostic value of pulsatility index, flow velocity, and their ratio, measured with TCD ultrasound, in patients with a recent TIA or ischemic stroke

BACKGROUND - Increased flow velocities, and combinations of low mean flow velocity (MFV) and a high pulsatility index (PI) are associated with intracranial arterial disease. We investigated the association of MFV and the ratio of PI and MFV (PI-MFV ratio) in the middle cerebral artery (MCA) with recurrence of vascular events in patients with a transient ischemic attack (TIA) or minor ischemic stroke. METHODS - Five hundred and ninety-eight consecutive patients underwent TCD investigation. Outcome events were fatal or non-fatal stroke and the composite of stroke, myocardial infarction, or vascular death (major vascular events). Hazard ratios (HR) were estimated with Cox proportional hazards multiple regression method, adjusted for age, gender, and vascular risk factors. RESULTS - TCD registration was successful in 489 patients. Mean follow-up was 2.1 years. Cumulative incidence was 9% for all stroke and 12% for major vascular events. MFV over 60.5 cm/s increased the risk for both stroke (HR 2.8; 95% CI: 1.3-6.0) and major vascular events (HR 2.6; 95% CI: 1.3-5.0). Each unit increase in PI-MFV ratio was associated with a HR 2.8 (95% CI: 1.7-4.8) for stroke and HR 2.2 (95% CI: 1.3-3.6) for major vascular events. CONCLUSION - In patients with a TIA or non-disabling ischemic stroke, MFV and the PI-MFV ratio in the MCA are independent prognostic factors for recurrent vascular events.

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.

Endovascular treatment of symptomatic intracranial stenosis with the Wingspan stent system and Gateway PTA balloon: a multicenter series of 60 patients with acute and midterm results

Object

The limitations of the medical management of symptomatic intracranial arterial stenosis (SIAS) have encouraged the development of new strategies, such as endovascular treatment. In this study, the authors report and analyze a series of 63 endovascular procedures in which the Wingspan stent system was used.

Methods

Data from 60 patients presenting with refractory SIAS, treated in 5 French neurointerventional centers between September 2006 and August 2009, were retrieved. An angiogram was systematically obtained 6 months after the procedure and yearly thereafter. The clinical neurological status was assessed and reported using the modified Rankin scale at 1-month, 6-month, and 1-year follow-up visits.

Results

A total of 63 stenotic lesions was treated. The mean age of the patients was 65.3 years, and the mean diameter of the stenosis was 80.2%. Technical success was achieved in 95.2% of cases. The overall incidence of procedural complications was 20.6%, with a 4.8% rate of permanent postoperative morbidity and death. In-stent restenosis (ISR)/occlusion occurred in 11 cases (17.4%), of which 10 were asymptomatic and 9 were detected less than 1 year from the endovascular treatment. In 1 case, the patient presented with a recurrent transient ischemic attack and was treated again with angioplasty. The mean follow-up was 13.2 months.

Conclusions

Endovascular treatment of SIAS demonstrates a moderate risk of neurological complication. Nevertheless, considering the critical natural history of severe refractory lesions, this may be considered the first alternative in cases of failed medical therapy. Technical failure, residual stenosis, or in-stent restenosis did not lead to systematic recurrent stroke in this series, which suggests the importance of plaque stabilization and neoendothelialization.

Intracranial atherosclerotic disease

Intracranial atherosclerotic disease (ICAD) is the most common proximate mechanism of ischemic stroke worldwide. Approximately half of those affected are Asians. For diagnosis of ICAD, intra-arterial angiography is the gold standard to identify extent of stenosis. However, noninvasive techniques including transcranial ultrasound and MRA are now emerging as reliable modalities to exclude moderate to severe (50%-99%) stenosis. Little is known about measures for primary prevention of the disease. In terms of secondary prevention of stroke due to intracranial atherosclerotic stenosis, aspirin continues to be the preferred antiplatelet agent although clopidogrel along with aspirin has shown promise in the acute phase. Among Asians, cilostazol has shown a favorable effect on symptomatic stenosis and is of benefit in terms of fewer bleeds. Moreover, aggressive risk factor management alone and in combination with dual antiplatelets been shown to be most effective in this group of patients. Interventional trials on intracranial atherosclerotic stenosis have so far only been carried out among Caucasians and have not yielded consistent results. Since the Asian population is known to be preferentially effected, focused trials need to be performed to establish treatment modalities that are most effective in this population.

Indications and applications of arterial stents for stroke prevention in atherosclerotic intracranial stenosis

Intracranial stenosis accounts for 8-10% of all ischemic strokes in North America, a frequency slightly less than that of extracranial carotid stenosis. Among patients presenting with transient ischemic attack or stroke due to intracranial stenosis, the risk of recurrent stroke in the first year after initial symptoms is about 14%. Those with high-risk features (recent stroke and severe stenosis) have up to a 23% rate of recurrent stroke in the year after their initial event. Angioplasty with stenting has emerged as a potential treatment strategy, particularly in high-risk patients, although evidence is currently limited to uncontrolled prospective trials and retrospective case series. In this article, we critically review the clinical results supporting the use of stenting and highlight some key considerations in the application of this technology, including patient selection, procedural management, technical issues, and risk factors for complications and in-stent restenosis.