Extracranial Internal Carotid Artery Stenosis Research Articles

Outcome of carotid artery stenting in the hands of vascular surgeons.

To analyze the procedural and clinical outcomes of carotid artery stenting (CAS) in the hands of endovascular trained vascular surgeons. Between April 2008 to May 2013, 1197 patients were treated for extracranial internal carotid artery (ICA) stenosis. The proportion of endovascular treated patients was 5.0% (CAS n=60 vs. carotid endarterectomy (CEA) n=1137). All patients in the CAS group (44 males, median age 70years) were treated by two senior vascular surgeons experienced in endovascular methods. Restenosis was the indication for CAS in 32 out of 60 patients (53.3%). Further indications were contralateral ICA occlusion (n=14, 23.3%), radiogenic ICA stenosis (n=5, 8.3%), high-risk candidates for CEA (n=4, 6.6%), and the presence of contralateral recurrent paresis (n=2, 3.3%). High-risk patients for CEA were defined as patients with history of severe cardiac disease and patients with impaired general condition. 84.4% (n=27) of the restenosis were asymptomatic with a mean degree of stenosis of 83.7%, and 12.9% (n=4) were symptomatic (degree of stenosis of 90%). Mean procedural and fluoroscopy time were 61 and 14min. Study endpoints were periprocedural stroke-related mortality and morbidity, restenosis rate, and overall survival. Follow-up was performed by duplex ultrasound with a median follow-up period of 12 months (range 1-55). The periprocedural stroke rate of CAS within 30 days was 3.3% (one ischemic stroke, one intracranial hemorrhage); two additional patients suffered TIA (3.3%). None of the patients had a myocardial infarction perioperatively. The mortality rate was 0. CAS procedures were completed in 90.0% (n=54) of cases. Dropout rate was 8.3% (n=5) for morphological reasons (e.g., carotid kinking). Intraoperative complication rate was 1.7% (n=1) including one patient who suffered intraoperative rupture of access vessels. The conversion rate with subsequent CEA procedure was 6.6% (n=4 of 5). The restenosis rate during follow-up was 3.3% after CAS. The reintervention rate during the median follow-up period of 12 months (1-55 months) was 5.5% (n=3/54). Two patients received a reintervention with successful balloon angioplasty; in one case, a diagnostic angiography was performed excluding the presence of a relevant restenosis. No additional stent was implanted. The survival rate was 100% at 1 year, 90.4% at 2 years, and 77.7% at 3 years. CAS, in the hands of vascular surgeons, is feasible with a moderate perioperative risk in a highly selected patient cohort. A procedure termination rate of approximately 10% shows that the complementary therapy using CAS procedure is not overused by surgeons.

Impact of MCA stenosis on the early outcome in acute ischemic stroke patients.

BackgroundAsians have higher frequency of intracranial arterial stenosis. The present study aimed to compare the clinical features and outcomes of ischemic stroke patients with and without middle cerebral artery (MCA) stenosis, assessed by transcranial sonography (TCS), based on the Taiwan Stroke Registry (TSR).MethodsPatients with acute ischemic stroke or transient ischemic attack registered in the TSR, and received both carotid duplex and TCS assessment were categorized into those with stenosis (≥50%) and without (<50%) in the extracranial internal carotid artery (ICA) and MCA, respectively. Logistic regression analysis, Kaplan-Meier method and Cox proportional hazard model were applied to assess relevant variables between groups.ResultsOf 6003 patients, 23.3% had MCA stenosis, 10.1% ICA stenosis, and 3.9% both MCA and ICA stenosis. Patients with MCA stenosis had greater initial NIHSS, higher likelihood of stroke-in-evolution, and more severe disability than those without (all p<0.001). Patients with MCA stenosis had higher prevalence of hypertension, diabetes and hypercholesterolemia. Patients with combined MCA and extracranial ICA stenosis had even higher NIHSS, worse functional outcome, higher risk of stroke recurrence or death (hazard ratio, 2.204; 95% confidence intervals, 1.440–3.374; p<0.001) at 3 months after stroke than those without MCA stenosis.ConclusionsIn conclusion, MCA stenosis was more prevalent than extracranial ICA stenosis in ischemic stroke patients in Taiwan. Patients with MCA stenosis, especially combined extracranial ICA stenosis, had more severe neurological deficit and worse outcome.

CREST-2: Identifying the Best Method of Stroke Prevention for Carotid Artery Stenosis: National Institute of Neurological Disorders and Stroke Organizational Update.

One of the great achievements of modern medicine is the successful prevention of stroke and other cardiovascular diseases. Although the incidence of stroke has substantially declined over the last 30 years, ≈200 000 preventable stroke deaths still occur annually in the United States. According to a recent study based on the Greater Cincinnati/Northern Kentucky Stroke Study, annually ≈41 000 strokes in the United States are attributed to extracranial internal carotid artery stenosis. Early revascularization for symptomatic carotid stenosis—that is, in patients with recent ipsilateral stroke or TIA—is well established as effective at preventing ipsilateral stroke. Carotid stenosis in the absence of symptoms is extremely common, but the best treatment is unclear. While 2 randomized trials showed a benefit of carotid endarterectomy (CEA) over antiplatelet therapy with aspirin, the number needed to treat approaches 200. Does aggressive risk factor control change that balance? Population screening for carotid stenosis followed by revascularization is considered to cause net harm. Are complication rates from endarterectomy and stenting now low enough to justify expanding their indications in asymptomatic patients? The National Institute of Neurological Disorders and Stroke (NINDS)–funded CREST-2 trial (Carotid Revascularization and Medical Management for Asymptomatic Carotid Stenosis Trial) is an ambitious attempt to further refine the treatment of asymptomatic carotid stenosis. As one of the largest randomized stroke prevention trials, the first CREST (Carotid Revascularization Endarterectomy Versus Stenting Trial) was designed to compare the safety and efficacy of 2 stroke prevention procedures for carotid artery narrowing—CEA and carotid artery stenting (CAS)—in symptomatic and asymptomatic individuals. Starting in December 2000, this NINDS-funded trial enrolled >2500 patients at 117 sites in the United States and Canada. Because of slow enrollment, the trial took 9 years to complete. In 2010, the results of CREST indicated that the 2 revascularization procedures were equivalent for …

Assessment of Endovascular Management of Extracranial Internal Carotid Artery Stenosis

Background: carotid artery stenting (CAS) had become widely used as an alternative to carotid endarterectomy (CEA) in revascularization therapy of carotid artery stenosis, especially in some high risk patients for surgical intervention. Objective: the purpose of this study was to evaluate the outcome and follow up of cases that undergo extracranial CAS at the Neuroendovascular Unit of Ain Shams University Hospital. Methods: during a 30 month period, 50 cases were enrolled and underwent carotid artery stenting with open cell (Protege® - EV3) or closed cell (Wall stent® - Boston scientific) stents. A filter device for embolic protection (Spider filter® - EV3) was used. Clinical assessment with the National Institute of Health Stroke Scale (NIHSS) together with post procedural diffusion-weighted magnetic resonance imaging (DW-MRI) was used to determine cerebral embolization. Results: CAS was performed in 50 cases; 40 (80%) symptomatic and 10 (20%) asymptomatic . A similar number of open-cell and closed-cell stents were used. New acute cerebral emboli were detected with DW-MRI in 12% (6/50) of cases after the procedure. Three (3/50) cases (6%) showed corresponding clinical deterioration in NIHSS; two cases developed minor stroke and the third case developed a major stroke. Conclusion: CAS at Ain Shams Neuroendovascular Unit showed a high technical success rate and good short term clinical outcome.

Silent Brain Infarction in Patients With Asymptomatic Carotid Artery Atherosclerotic Disease.

The relationship between carotid atherosclerosis and ipsilateral silent brain infarction (SBI) is unclear. We tested the hypothesis that extracranial internal carotid artery (ICA) stenosis is associated with a greater prevalence of SBI in the cerebral hemisphere ipsilateral to ICA disease compared with the unaffected, contralateral side. We identified patients with unilateral extracranial ICA stenosis ≥50% on angiography by standard imaging criteria. We included patients with recent brain magnetic resonance imaging who had no previous history of stroke or transient ischemic attack. Blinded readers ascertained the presence of anterior circulation SBIs. SBI was defined as either a cavitary lacunar infarction in the white or deep gray matter or cortical infarction defined by T2 hyperintense signal in cortical gray matter. The Wilcoxon signed-rank test was used to compare SBI in the cerebral hemispheres and Cohen κ to assess inter-rater reliability of SBI evaluation. Among 104 patients, we found a higher prevalence of SBIs ipsilateral to ICA disease (33%) compared with the contralateral side (20.8%; P=0.0067). There was no significant difference in the prevalence of lacunar SBIs (including both white and deep gray matter) between hemispheres (P=0.109), but there was a significantly higher prevalence of cortical SBIs occurring downstream from ICA disease (P=0.0045). High inter-rater reliability was observed (κ=0.818). Patients with asymptomatic ICA disease demonstrate a higher prevalence of SBI downstream from their ICA atherosclerotic disease compared with the contralateral side but only of the cortical and not lacunar SBI subtype.

Extracranial internal carotid artery stenosis in children with sickle cell disease - Which transducer, what measurement?

Transcranial Doppler ultrasound is used to screen and assess the intracranial arteries of children with sickle cell disease. Recent findings suggest that extracranial internal carotid artery (eICA) stenosis is also a contributing factor to silent cerebral infarction. Stenosis has been measured using phased array transducers with no beam/flow angle correction and linear arrays with angle correction. A total of 124 children undergoing TCD assessment were investigated for eICA velocities. Manual measurements of peak systolic velocity and TCD mean velocity were made with phased and linear array transducers. Peak systolic velocities ranged from 60 to 534 cm/s (median 126 cm/s) using the linear array and 53 to 394 cm/s (median 115 cm/s) using the phased array transducers. TCD mean ranged from 39 to 419 cm/s (median 81 cm/s) using the linear array and 34 to 295 cm/s (median 72 cm/s) using the phased array transducers. There are advantages and disadvantages of each method, but stenoses were readily identified as focal velocity increases. We suggest thresholds for each transducer and recommend that imaging of the eICA forms part of screening for this group of children.

Higher Levels of Cystatin C Are Associated with Extracranial Carotid Artery Steno-Occlusive Disease in Patients with Noncardioembolic Ischemic Stroke

Background: Large artery atherosclerosis is a major cause of ischemic stroke worldwide. Differential biomarker profiles associated with extra- and intracranial atherosclerosis are a topic of considerable interest. Cystatin C (CysC), a marker of renal function, is a risk factor for cardiovascular disease. Aim: We sought to determine whether CysC levels were associated with extra- and intracranial large artery stenosis (LAS) in patients with acute ischemic stroke. Methods: We retrospectively analyzed data of acute noncardioembolic ischemic stroke patients who were admitted to our stroke center within 5 days from symptom onset. Serum CysC levels were measured using latex agglutination turbidimetric immunoassay. Extra- and intracranial LAS were defined as ≥50% diameter stenosis or occlusion of the relevant internal carotid artery (ICA) and/or middle cerebral artery (MCA) using carotid echography and volume rendering on magnetic resonance angiography. Multivariate logistic analyses were used to assess the association between CysC levels and LAS after adjustment for potential confounders. Results: Of 205 patients (mean age 70.2 years), 76 (37.1%) had LAS. The distribution of LAS was 29 extracranial ICA, 34 intracranial ICA/MCA (8 ICA only, 25 MCA only, 1 ICA+MCA) and 13 tandem stenosis (both extracranial ICA and intracranial ICA/MCA). Levels of CysC were higher in patients with extracranial ICA stenosis than in those with intracranial ICA/MCA stenosis (1.23 ± 0.33 vs. 0.97 ± 0.21 mg/l, p < 0.001). In multivariate analysis, the highest CysC tertile (>1.04 mg/l) was significantly associated with extracranial ICA stenosis (adjusted odds ratio [OR] 5.01, 95% confidence interval [CI] 1.51-16.63, p = 0.009) after adjustment for age, sex, diabetes, chronic kidney disease, current smoking, systolic blood pressure, HDL cholesterol, high-sensitivity C-reactive protein (hs-CRP) and premorbid lipid-lowering drugs use. When CysC was considered as a continuous variable, 1 SD increase in CysC was significantly associated with extracranial ICA stenosis (adjusted OR 3.01, 95% CI 1.58-5.72, p = 0.001). However, there were no significant associations between CysC levels and intracranial ICA/MCA stenosis. In addition, CysC levels showed a weak but statistically significant correlation with hs-CRP levels (r = 0.195, p = 0.021). Using receiver operating characteristic curve analysis, CysC value displayed good performance in discriminating extracranial ICA stenosis (c-statistic 0.79, 95% CI 0.69-0.89, p < 0.001). Conclusions: This preliminary study suggests that higher levels of CysC were independently associated with symptomatic extracranial ICA stenosis, but not with intracranial ICA/MCA stenosis in patients with noncardioembolic stroke. Our findings provide new insights into the link between serum CysC and carotid atherosclerosis.

Extracranial internal carotid artery stenosis associated with internal carotid artery aneurysm: a rare case in the literature

Extracranial internal carotid artery stenosis associated with internal carotid artery aneurysm: a rare case in the literature

Initial Clinical Experience With the Micromesh Roadsaver Carotid Artery Stent for the Treatment of Patients With Symptomatic Carotid Artery Disease

Purpose: To assess the effectiveness, technical aspects, handling, and safety of the micromesh Roadsaver Carotid Artery Stent in the treatment of atherosclerotic carotid artery stenosis and tandem lesions in ischemic stroke patients. Methods: Seven patients (5 men; mean age 75±11.4 years, range 53–86) suffering from symptomatic internal carotid artery (ICA) stenosis (mean 76% diameter reduction) were treated with the dual layer closed-cell stent without embolic protection. Postdilation was performed in 6 of 7 patients. Two patients were treated in the context of ischemic stroke and concurrent middle cerebral artery occlusion. Mean National Institutes of Health Stroke Scale score at admission was 12.8±5. Results: All devices were deployed satisfactorily. One wall-adherent thromboembolus in a proximal ICA was covered with the Roadsaver stent in a tandem lesion setting. The modified Rankin Scale (mRS) declined from 3.7±0.7 to 2.4±0.8 in hospital, showing an improvement in clinical symptoms. No complications were detected during or after the procedure. The 30-day mRS was 1.7±1.1. At 6 months, ultrasound examination demonstrated patency of stents and the external carotid arteries. Conclusion: The Roadsaver double layer micromesh stent seems to be safe and effective in the treatment of extracranial ICA stenosis and in the context of tandem lesions in ischemic stroke. Further studies with larger populations are warranted.

Abstract W MP21: Diagnostic Accuracy of CT-Angiography for Internal Carotid Artery Stenosis - Comparison with a Revisited Multiparametric Ultrasound Approach

Background: A novel multiparametric approach from the Neurosonology Research Group (NSRG) of the World Federation of Neurology has been proposed for duplex ultrasound (DUS) grading of internal carotid artery (ICA) stenosis. We aimed to determine the accuracy of CT-angiography (CTA) compared with the widely used NSRG ultrasound criteria for diagnosis of extracranial ICA stenosis. Methods: We studied consecutive acute ischemic stroke patients who were admitted to our tertiary stroke center from 01/2012 to 12/2012 and underwent CTA and DUS. On DUS, ICA stenosis and complete occlusion were graded according to the published NSRG multiparametric criteria. Axial CTA source images were independently assessed and NASCET-type measurements were manually performed for each extracranial ICA. In addition, each ICA was reviewed for complete occlusion. We calculated accuracy parameters of CTA for identification of 50-99% and 70-99% ICA stenosis, as well as complete ICA occlusion using DUS as reference. Results: A total of 339 patients (age 72±12yrs; 58% men; median NIHSS 4, interquartile range 8) provided 651 DUS and CTA measurement pairs for comparison. On DUS, 50-99% stenosis was found in 28, 70-99% stenosis in 16, and complete occlusion in 29 internal carotid arteries. The sensitivity of CTA against DUS was low for both detection of 50-99% and 70-99% ICA stenosis (64% and 31%, respectively). Further accuracy parameters of CTA were as follows: specificity 97%, PPV 49%, NPV 98% and overall accuracy 96% (18 true positive, 604 true negative, 19 false positive and 10 false negatives), and 99%, 56%, 98% and 98% (5 true positive, 631 true negative, 4 false positive and 11 false negatives), respectively. The highest accuracy of CTA was obtained for discriminating between complete ICA occlusion and non-occlusion: 100%, 96%, 91%, 100% and 99%. Conclusions: In comparison with the new and widely used NSRG criteria, CTA NASCET-type measurements seem to underestimate the degree of extracranial ICA stenosis. The validity of the NSRG criteria is currently evaluated in a prospective multicenter validation study utilizing invasive angiography as the gold standard.

Imaging of the Vulnerable Carotid Plaque: Biological Targeting of Inflammation in Atherosclerosis using Iron Oxide Particles and MRI

Identification of those patients with high-risk asymptomatic carotid plaques remains an elusive but essential step in stroke prevention. Inflammation is a key process in plaque destabilization and the propensity of atherosclerotic lesions to cause clinical sequelae. There is currently no clinical imaging technique available to assess the degree of inflammation associated with plaques. This study aims at visualizing and characterizing atherosclerosis using antibody-conjugated superparamagnetic iron oxide (SPIO) particles as an MRI probe to assess inflammation in human atherosclerotic plaques. Atherosclerotic plaques were collected from 20 consecutive patients (n=10 from symptomatic patients, n=10 from asymptomatic patients) undergoing carotid endarterectomy (CEA) for extracranial high-grade internal carotid artery (ICA) stenosis (>70% luminal narrowing). Inflammatory markers on human atherosclerotic plaques were detected and characterized by ex vivo magnetic resonance imaging (MRI) using anti-VCAM-1 antibody and anti-E-selectin antibody-conjugated SPIO with confirmatory immunohistochemistry. Inflammation associated with human ex vivo atherosclerotic plaques could be imaged using dual antibody-conjugated SPIO by MRI. Symptomatic plaques could be distinguished from asymptomatic ones by the degree of inflammation, and the MR contrast effect was significantly correlated with the degree of plaque inflammation (r=.64, p<.001). The asymptomatic plaque population exhibited heterogeneity in terms of inflammation. The dual-targeted SPIO-induced MR signal not only tracked closely with endothelial activation (i.e. endothelial expression of VCAM-1 and E-selectin), but also reflected the macrophage burden within plaque lesions, offering a potential imaging tool for quantitative MRI of inflammatory activity in atherosclerosis. These functional molecular MRI probes constitute a novel imaging tool for ex vivo characterization of atherosclerosis at a molecular level. Further development and translation into the clinical arena will facilitate more accurate risk stratification in carotid artery disease in the future.

Evaluation of cerebrovascular reserve using xenon-enhanced CT scanning in patients with symptomatic middle cerebral artery stenosis

Cerebrovascular reserve (CVR) is an important prognostic factor in patients with major cerebral arterial steno-occlusive disease. However, few studies have examined CVR in symptomatic intracranial stenosis without ipsilateral extracranial internal carotid artery stenosis. This study sought to evaluate CVR in patients with symptomatic middle cerebral artery (MCA) stenosis using xenon-enhanced computed tomography (Xe/CT) with acetazolamide (ACZ) challenge. Twelve patients with symptomatic MCA stenosis were recruited. All patients were examined by Xe/CT to quantitatively measure resting cerebral blood flow (CBF) and received ACZ challenge to evaluate CVR. For resting CBF, no significant differences were found between the sides in four regions of interest. After the ACZ challenge test, the CVR was significantly different between hemispheres (ipsilateral versus contralateral CVR: 12.9±24.3% versus 28.0±16.8%, respectively; p=0.005) and in the MCA territory (ipsilateral versus contralateral CVR: 8.7±24.7% versus 29.3±24%, respectively; p=0.003). However, no significant differences in CVR were detected between cortical comparisons and white matter comparisons from the two sides. Thus, ACZ-challenge Xe/CT is useful for the measurement of CBF and CVR in these patients. Impaired CVR is an important characteristic of patients with symptomatic MCA stenosis.

Coexistence of Internal Carotid Artery Stenosis with Intracranial Aneurysm

Studies have hypothesized that alterations in haemodynamics and rheological properties in the main vessels like the main stem of the carotid artery or the internal carotid arteries are responsible for the formation of cerebral aneurysms. The objectives of the current analyses were to collate data that have examined the occurrence of cerebral aneurysm with coexisting internal carotid artery stenosis. Data sources were collated from detailed PubMed search obtained from 1990 till current. Published literature that deals with the epidemiologic properties as well as prevalence was scanned for data extraction. Publications that reported coexistence of internal carotid artery stenosis with intracranial aneurysm, detected by any modality of imaging, was included in the current study. Spearman's correlation analyses were used to obtain significant information of coexistence of an intracranial aneurysm with an extracranial internal carotid artery stenosis. The frequency of concurrent extracranial internal carotid artery stenosis and an unruptured cerebral artery aneurysm is not known exactly, but has been estimated to be approximately 4%. The major limitations of the current analyses actually can be retrospectively traced to the lack of detailed analyses in this important area of investigation. Although low in absolute occurrence, there is a significant correlation of the existence of an intracranial aneurysm with carotid artery stenosis. Thus, if peripheral stenosis is detected by any imaging modality including carotid Ultrasonography scan, we recommend digital subtraction intracranial angiography to detect any potential aneurysm and define its radiologic morphology.

Acceleration time ratio for the assessment of extracranial internal carotid artery stenosis.

To apply the acceleration time (AcT) ratio as an additional marker for diagnosing internal carotid artery (ICA) stenosis. Carotid artery sonography was performed in 140 patients, and the AcT ratio was calculated as the AcT of the ICA divided by the AcT of the ipsilateral common carotid artery, and compared with diameter stenosis. There was a significant correlation between diameter stenosis and the AcT ratio. The receiver operating characteristic curve revealed a cutoff level of 1.5, with 90.0% sensitivity and 93.5% specificity for stenosis >65%. Our results indicate that applying the AcT ratio can help in the diagnosis of ICA stenosis.

Periprocedural Thromboembolic Events Associated with Angioplasty and Stenting of the Extra- and Intracranial Carotid Artery Assessed by Neurological Status and Diffusion-Weighted Magnetic Resonance Imaging (DWI)

Objective. The purpose of this study was to determine the frequency of thromboembolic events associated with angioplasty and stenting of the carotid artery with special regard to extra- or intracranial localization of stenosis. Methods. Twenty patients with symptomatic intracranial or extracranial internal carotid artery stenosis were treated with stenting and/or angioplasty. In 4 patients stenting was technically not feasible (all in the group with intracranial stenosis). All patients underwent diffusion-weighted imaging (DWI) and neurological examination within 48 hours before and after the procedure to detect periprocedural thrombembolic events. Results. Extracranial carotid angioplasty and stenting (eCAS) was technically feasible and successfull without procedure-related neurological complications in all cases. Intracranial stenting (iCAS) was not feasible in four cases including one patient with a fateful course. Concerning the restoration of the vessel diameter intracranial stenting was not as successful as eCAS, but more effective than balloon angioplasty alone. Incidence of thrombembolic events assessed by DWI was low. The detected periprocedural thrombembolic events were small and clinically silent. Conclusion. The risk of thromboembolic events during the endovascular treatment of symptomatic carotid artery stenosis was rather low for intra- and extracranial stenosis of the ICA in our patient sample, but one fatal course was observed.

Carotid Artery Stenosis as a Cause of Stroke

Background: Population-based studies have estimated that about 15% of ischemic strokes are caused by large-vessel cerebrovascular disease. We determined the types of large-vessel atherosclerosis responsible for ischemic strokes in a population-based stroke study. Methods: Patients with first-ever or recurrent ischemic stroke in the Greater Cincinnati area were identified during 2005 at all local hospitals. Study physicians assigned ischemic stroke subtypes. Overall event rates and incidence rates for first-ever events were calculated, and age-, race- and sex-adjusted to the 2000 US population. Results: There were 2,204 ischemic strokes, including 365 strokes of large-vessel subtype (16.6% of all ischemic strokes). Extracranial internal carotid artery (ICA) stenosis was associated with 8.0% of all ischemic strokes, while extracranial ICA occlusion and intracranial atherosclerosis were each associated with 3.5% of strokes. The annual rate of first-ever and recurrent stroke attributed to extracranial ICA was 13.4 (11.4–15.4) per 100,000 persons. We conservatively estimate that about 41,000 strokes may be attributed to extracranial ICA stenosis annually in the United States. Conclusions: Large-vessel atherosclerosis is an important cause of stroke, with extracranial ICA stenosis being significantly more common than extracranial ICA occlusion or intracranial atherosclerotic disease.

Ischaemic Stroke - Stenting versus Surgery for Carotid Disease

Extracranial internal carotid artery stenosis is one of the most common and best studied causes of stroke. Revascularisation with carotid endarterectomy (CEA) has been shown to be beneficial for patients with severe stenosis associated with stroke or transient ischaemic attack (TIA) and for many patients with moderate stenosis associated with stroke or TIA. CEA has also been shown to be beneficial for patients with asymptomatic severe stenosis if they have a reasonable expected lifespan and surgical risk, but the benefit is greater for men compared with women. Carotid angioplasty and stenting (CAS) has become a viable alternative procedure for carotid revascularisation with less risk of major bleeding complications and cranial nerve injury. Randomised studies of CEA versus CAS have found that the endovascular approach is associated with a lower risk of myocardial infarction but a higher risk of peri-procedural stroke which has a greater impact on long-term quality of life. Thus, recommending CEA or CAS must be based upon individual patient characteristics and their preferences, but at this point it appears that most patients should still be receiving CEA if an intervention is required.

Predictors of Tissue-Type Plasminogen Activator Nonresponders According to Location of Vessel Occlusion

Information on the clinical and hemodynamic profile of intravenous tissue-type plasminogen activator nonresponders, at different locations of arterial occlusion, may improve the selection of candidates for rescue reperfusion therapies. Therefore, we aim to investigate predictors of failing intravenous tissue-type plasminogen activator therapy according to occluded vessel and location of the clot. We prospectively evaluated consecutive patients with an acute ischemic stroke admitted within the first 6 hours of onset. Five hundred forty-eight patients with documented intracranial occlusion were included. Patients were categorized according to site of vessel occlusion into 4 distinct groups: proximal middle cerebral artery occlusion (n=251), distal middle cerebral artery occlusion (n=194), internal carotid artery bifurcation occlusion (n=61), and basilar artery occlusion (n=42). Recanalization was assessed on transcranial Doppler at 1 hour of tissue-type plasminogen activator bolus. Among patients with proximal middle cerebral artery occlusion, the presence of severe extracranial internal carotid artery stenosis or occlusion (OR, 2.36; 95% CI, 1.15-4.84; P=0.02) and age >74 years (OR, 1.84; 95% CI, 1.02-3.31; P=0.04) independently predicted no recanalization. No independent predictors of no recanalization were identified in patients with distal middle cerebral artery occlusion. In patients with internal carotid artery bifurcation occlusion, a previous diagnosis of hypertension (OR, 12.77; 95% CI, 2.12-76.88; P=0.05), and absence of atrial fibrillation (OR, 8.15; 95% CI, 1.40-47.44; P=0.02) emerged as independent predictors of no recanalization. Similarly, among patients with basilar artery occlusion, absence of atrial fibrillation was as an independent predictor of no recanalization (OR, 7.50; 95% CI, 1.40-40.35; P=0.02). The use of relevant predictors of no recanalization and a rapid neurovascular evaluation may improve the selection of patients for more aggressive rescue strategies.

Improvement in executive function after unilateral carotid artery stenting for severe asymptomatic stenosis

Executive functions are crucial for organizing and integrating cognitive processes. While some studies have assessed the effect of carotid artery stenting (CAS) on cognitive functioning, results have been conflicting. The object of this study was to assess the effect of CAS on cognitive status, with special interest on executive functions, among patients with severe asymptomatic internal carotid artery (ICA) stenosis. The authors prospectively assessed the neuropsychological status of 20 patients with unilateral asymptomatic extracranial ICA stenosis of 60% or more by using a comprehensive assessment battery focused on executive functions before and after CAS. Individual raw scores on neuropsychological tests were converted into z scores by normalizing for age, sex, and years of education. The authors compared baseline and 3-month postoperative neuropsychological scores by using Wilcoxon signed-rank tests. The mean preoperative cognitive performance was within normal ranges on all variables. All patients underwent a successful CAS procedure. Executive function scores improved after CAS, relative to baseline performance as follows: set shifting (Trail-Making Test Part B: -0.75 ± 1.43 vs -1.2 ± 1.48, p = 0.003) and processing speed (digit symbol coding: -0.66 ± 0.85 vs -0.97 ± 0.82, p = 0.035; and symbol search: -0.24 ± 1.32 vs -0.56 ± 0.77, p = 0.049). The benefit of CAS for working memory was marginally significant (digit span backward: -0.41 ± 0.61 vs -0.58 ± 0.76, p = 0.052). Both verbal (immediate Rey Auditory Verbal Learning Test: 0.35 ± 1.04 vs -0.22 ± 0.82, p = 0.011) and visual (delayed Rey-Osterrieth Complex Figure: 0.27 ± 1.26 vs -0.22 ± 1.01, p = 0.024) memory improved after CAS. The authors found a beneficial effect on executive function and memory 3 months after CAS among their prospective cohort of consecutive patients with unilateral and asymptomatic ICA stenosis of 60% or more.

Reply:

We thank Dr Linn for her response to our letter entitled “Extracranial Internal Carotid Artery Stenosis as a Cause of Cortical Subarachnoid Hemorrhage.”[1][1] We certainly agree that cerebral amyloid angiopathy (CAA) is an important cause of focal sulcal subarachnoid hemorrhage (fsSAH) in the