High-grade Internal Carotid Artery Stenosis Research Articles

Recruitment of pial collaterals and carotid occlusive disease in large-vessel occlusion ischemic stroke

Background and purposeDespite the fundamental role of pial collateral vessels in limiting the progression of ischemic tissue injury in acute stroke with large vessel occlusion (LVO), in addition to the fact that collateral vessel abundance varies naturally from person to person for genetic reasons, there is limited knowledge regarding potential factors contributing to inherent interindividual variation in pial collateral supply. As it has been repeatedly hypothesized that chronic carotid occlusive disease may favor pial collateralization, we aimed to investigate the association between quantitatively assessed leptomeningeal collateral supply and pre-existing carotid stenosis in patients with acute stroke due to LVO.Materials and methodsPatients with proximal middle cerebral artery (MCA) occlusion with or without additional internal carotid artery (ICA) occlusion were included. The degree of collateral supply was quantitatively assessed based on signal variance in T2*-weighted time series in perfusion-weighted magnetic resonance imaging (PWI). Patients were stratified into two groups according to quantitative collateral status (poor and fair to good collateral supply). The prevalence of high-grade ICA stenosis (≥70%) was evaluated in both groups.ResultsA total of 98 patients (mean age 68.8 ± 16.1 years, n = 52 (53.1%) of whom were female individuals) with MCA and/or ICA occlusion were included in the final analysis. Out of these patients, 42 had poor collateral supply, while 56 exhibited fair to good collateral supply. Additionally, 18 patients showed ipsilateral high-grade ICA stenosis. After classifying the entire cohort based on their collateral status (poor vs. fair to good collateral supply), there was no significant difference in the proportion of the patients with ipsilateral high-grade ICA stenosis between the two groups. Specifically, 6 (14.3%) patients had poor collateral supply, and 12 (21.1%) patients had fair to good collateral supply. The odds ratio (OR) was 1.58, with a 95% confidence interval (CI) of 0.490–5.685 and the p-value of 0.440. In the entire patient cohort, signal variance-based collateral supply was significantly correlated with initial stroke severity (r = −0.360, p < 0.001), baseline ischemic core volume (r = −0.362, p < 0.001), and functional outcomes (score on the modified Rankin Scale) at discharge (r = −0.367, p < 0.01).ConclusionIn this study, we performed a quantitative and observer-independent MRI-based collateral assessment in patients with LVO. We found no significant difference in the prevalence of pre-existing high-grade ICA stenosis between patients with fair to good collateral supply and those with poor collateral supply. The potential influence of demographic and clinical variables on pial collateral supply in patients with acute stroke warrants further exploration in future studies. MRI-based collateral supply is significantly related to initial stroke severity, ischemic core volume, and early functional outcomes.

Superficial temporal artery access for transfemoral or transbrachial carotid artery stenting in selected patients considered unfit for carotid surgery.

Transfemoral (TFCAS) or transbrachial carotid artery stenting (TBCAS) is an alternative to carotid endarterectomy (CEA) for treatment of high-grade internal carotid artery (ICA) stenosis. A difficult aortic arch (i.e., type III or bovine arch) and/or a tortuous/stenosed common carotid artery (CCA) are potential reasons for technical failure. This study explores the benefits of superficial temporal artery access (STAA) in aiding TFCAS or TBCAS for patients with challenging anatomical conditions. Clinical data of patients who underwent TFCAS or TBCAS using STAA between January and November 2023 were prospectively collected. Demographics, comorbidities, clinical presentation, and imaging studies were reviewed. Primary outcomes included 30-day stroke/death and technical success. Secondary outcomes and causes of failures were assessed. Ten patients (mean age: 74 [range: 66-84] years) with difficult aortic arch (N.=2), CCA tortuosity (N.=2), proximal CCA stenosis (N.=2), previous technical TFCAS failure (N.=2) and aortoiliac occlusive disease (AIOD) (N.=2) underwent TFCAS or TBCAS supported by STAA. Successful STAA was possible in eight patients (six facilitated TFCAS and two TBCAS. after TBCAS occurred TIA). In two cases STAA was not successful. There were no deaths or strokes within 30 days, transient ischemic attack (TIA) occurred in one patient. Follow-up Duplex ultrasound confirmed occlusion of the STA in all patients, without clinical consequences. This prospective study suggests that TFCAS/TBCAS supported by STAA is a viable and safe approach when traditional access methods are ineffective and transcarotid artery stenting in not available or not possible. Despite a 20% technical failure in the current series, this technique may be useful for challenging anatomy of the aortic arch, CCA stenosis and tortuosity, and AIOD. When feasible, STAA may be a promising adjunct to TFCAS/TBCAS.

Abstract 1145: A Computational Fluid Dynamics Analysis Of Hemodynamic Differences In Patients With High Grade Asymptomatic Carotid Artery Stenosis

Introduction: Current assessment/management of internal carotid artery (ICA) stenosis is based on estimation of percentage (%) stenosis which does not account for trans-lesional flow, pressure gradient (PG), wall shear stress (WSS), or oscillatory shear index (OSI). Computation fluid dynamics (CFD) can be used to characterize such indices. Hypothesis: We hypothesize that patients asymptomatic >70% ICA stenosis will have hemodynamic differences that are independent of % stenosis. Aims: Evaluate hemodynamic indices in patients with asymptomatic >70% ICA stenosis via CFD. Methods: Patients with asymptomatic >70% ICA stenosis were included. 3D time-of-flight (TOF) and phase-contrast (PC) magnetic resonance imaging (MRI) sequences were obtained. CRIMSON was used to generate CFD models containing the carotid artery (CCA), ICA, and external carotid artery (ECA). PC MRI-derived flow waveforms were prescribed to the CCA and ECA. The ICA outlet was coupled to a three-element Windkessel model. Blood was modeled as an incompressible Non-Newtonian fluid with a dynamic viscosity of 0.004 kg m –1 s –1 and a density of 1,060 kg m -3 . Incompressible Navier-Stokes equations were used to solve for velocity and pressures. Results: Eight patients (average age 73.8 years, 62.5% male) with asymptomatic high-grade ICA stenosis (62.5% left) were included. Hypertension (87.5%), tobacco use (87.5%), and hyperlipidemia (75%) were common. Most patients were medically optimized with anti-hypertensive (100%), statin (87.5%), and aspirin (87.5%). Three patients (37.5%) underwent ICA intervention.. Mean peak systolic velocity was 406 cm/s and mean end-diastolic velocity was 127 cm/s. There was large variability in trans-lesional ICA flow, PG, WSS, and OSI (Table 1). Conclusions: Asymptomatic patients with the same % stenosis have differences in trans-lesional ICA flow, PG, WSS, and OSI. Future work is needed to determine the prognostic value of such differences.

Does Current Evidence Support Carotid Artery Stenting for Asymptomatic Patients?

Carotid interventions, carotid endarterectomy and carotid artery stenting (CAS) have proven to be effective treatments for the prevention of ischaemic stroke in recently symptomatic patients. Most studies were conducted before the development of strict statin guidance and the systematic use of antiplatelet drugs. The advances in medical treatments have raised questions regarding the benefit of carotid endarterectomy or CAS, especially for high-grade asymptomatic internal carotid artery stenosis. Reviewing the literature indicates that carotid artery stenosis of any degree is a relatively weak predictor of ipsilateral stroke, in the absence of recent symptoms referable to the carotid disease. This risk does not appear reduced by revascularisation by CAS if added to modern day best medical therapy. On-going trials are key to understanding if current techniques can provide an additional benefit.

Poststenotic Distal Caliber Reduction Predicts Very High-Grade Proximal Internal Carotid Artery Stenosis.

Angiography relates the residual lumen to the poststenotic distal lumen (NASCET criterion) and expresses the result in percent lumen reduction. This method is not applicable when there is a collapse of the distal lumen, as seen in severe stenosis. The purpose of this study was to evaluate whether the reduced poststenotic caliber could be an additional sonographic criterion for estimation of the degree of stenosis. We measured the caliber of the distal lumen of the extracranial internal carotid artery (ICA) in 57 patients with low-grade stenosis <50% (NASCET criterion), and in 57 patients with unilateral stenosis of ≥ 50 %. All were classified following international recommendations. The criteria used included the poststenotic velocity to discriminate moderate to high-grade stenosis (50-70%) from very high-grade (≥ 80 %) stenosis. In addition, we measured the interrater reliability of the ultrasonic measurement of the lumen in the distal ICA. In the group of patients with 50% to 70% stenosis, the distal lumen was 4.3 ± 0.6 mm. In the group with very high-grade stenosis ≥ 80%, the distal lumen was 2.6±0.5mm (p<0.0001). A distal lumen of 3.2 mm or less predicted a very high-grade stenosis with a sensitivity of 0.92 and a specificity of 0.96 (AUC 0.986; 95% CI 0.97-1.00; p=0.0001). The distal poststenotic lumen is an additional ultrasonic criterion to discriminate a very high-grade ICA stenosis from a lesser degree of ICA stenosis. It can help avoid misinterpretation due to the high variability of intrastenotic peak systolic velocities (PSV) in very high-grade ICA stenoses.

Resting-state BOLD functional connectivity depends on the heterogeneity of capillary transit times in the human brain A combined lesion and simulation study about the influence of blood flow response timing

Functional connectivity (FC) derived from blood oxygenation level dependent (BOLD) functional magnetic resonance imaging at rest (rs-fMRI), is commonly interpreted as indicator of neuronal connectivity. In a number of brain disorders, however, metabolic, vascular, and hemodynamic impairments can be expected to alter BOLD-FC independently from neuronal activity. By means of a neurovascular coupling (NVC) model of BOLD-FC, we recently demonstrated that aberrant timing of cerebral blood flow (CBF) responses may influence BOLD-FC. In the current work, we support and extend this finding by empirically linking BOLD-FC with capillary transit time heterogeneity (CTH), which we consider as an indicator of delayed and broadened CBF responses. We assessed 28 asymptomatic patients with unilateral high-grade internal carotid artery stenosis (ICAS) as a hemodynamic lesion model with largely preserved neurocognitive functioning and 27 age-matched healthy controls. For each participant, we obtained rs-fMRI, arterial spin labeling, and dynamic susceptibility contrast MRI to study the dependence of left-right homotopic BOLD-FC on local perfusion parameters. Additionally, we investigated the dependency of BOLD-FC on CBF response timing by detailed simulations. Homotopic BOLD-FC was negatively associated with increasing CTH differences between homotopic brain areas. This relation was more pronounced in asymptomatic ICAS patients even after controlling for baseline CBF and relative cerebral blood volume influences. These findings match simulation results that predict an influence of delayed and broadened CBF responses on BOLD-FC. Results demonstrate that increasing CTH differences between homotopic brain areas lead to BOLD-FC reductions. Simulations suggest that CTH increases correspond to broadened and delayed CBF responses to fluctuations in ongoing neuronal activity.

Intrinsic functional brain connectivity is resilient to chronic hypoperfusion caused by unilateral carotid artery stenosis

IntroductionChronic cerebral hypoperfusion caused by asymptomatic high-grade stenosis of the internal carotid artery (ICA) has been associated with impaired cognitive function. Only few studies exist on underlying changes of functional connectivity (FC). Methods20 patients with unilateral high-grade ICA stenosis without MRI lesions and 25 aged-match controls underwent resting-state functional MRI (rsfMRI) and neuropsychological assessment. Patients were examined within ten days before and 6–10 weeks after surgical or interventional revascularization of carotid stenosis. We examined mean resting-state FC ipsi- and contralateral to stenosis and network topology using graph-theoretical measures. ResultsAt baseline, intrahemispheric FC was similar for patients and healthy controls. After revascularization mean FC increased moderately without an effect on network topology. Patients performed worse in TMT B and Stroop test, while performance in global screening tests for dementia (Mini Mental Status Examination, DemTect) were comparable. Test results did not improve after revascularization. ConclusionIn our study population, we find no effect of chronic hypoperfusion on FC and global cognitive function, although we observe minor impairments in processing speed and mental flexibility. The subtle increase of FC after revascularization could indicate excessive upregulation after restoration of perfusion. However, it might as well be a coincidental finding due to the limited sample size.

Commentary: Stenting in High-Grade Internal Carotid Artery Stenosis: 2-Dimensional Operative Video

Commentary: Stenting in High-Grade Internal Carotid Artery Stenosis: 2-Dimensional Operative Video

Stenting in High-Grade Internal Carotid Artery Stenosis: 2-Dimensional Operative Video.

Carotid artery stenosis is implicated in up to 40% of all ischemic strokes. Accordingly, symptomatic, high-grade carotid artery stenosis portends an especially high risk of future stroke. Intervention via open or endovascular approaches drastically reduces this risk. Under the appropriate conditions, carotid artery stenting serves as a safe and effective alternative to carotid endarterectomy. We present the case of a 57-yr-old male with symptomatic, high-grade stenosis of his right internal carotid artery, for whom a history of radiation to the head and neck represented a relative contraindication to carotid endarterectomy, and thus endovascular treatment with angioplasty and stenting was performed. Informed consent was obtained prior to the procedure. Intraprocedurally, stent delivery past the area of stenosis proved somewhat challenging. However, by employing several nuanced maneuvers, we utilized our guiding catheter in a nonconventional manner in order to successfully perform the procedure. As the field of neuroendovascular surgery evolves, each case provides us unique lessons, which in turn expands our interventional capabilities and adds to the armamentarium of neuroendovascular techniques. We present this surgical video both as a means to provide a general overview of carotid artery stenting, and to share a lesson learned through the implementation of an interesting technical nuance.

Transcarotid artery revascularization (TCAR) – first experience

Abstract Objective In transcarotid artery revascularization (TCAR) the carotid stent used to treat carotid artery stenosis is introduced via a cut-down to the common carotid artery (CCA). Stent placement is performed during flow reversal using an external shunt to the femoral vein. The advantages compared to transfemoral carotid stenting are that the risks of embolization from the aortic arch and origin of the arch vessels are avoided and that clamping of the common carotid artery allows complete flow-reversal during stent placement. TCAR was developed in 2015 and is extensively used predominately in the USA. To our knowledge, TCAR has until now not been used in Switzerland. We present our first experience with TCAR. Methods Retrospective analysis of consecutive patients. Results We treated 4 patients with TCAR from Dec 2019 to May 2020. All patients were male, median age was 66y. All had high-grade internal carotid artery (ICA) stenosis (3 asymptomatic, 1 symptomatic). All procedures were performed in a hybrid operation room. Technical success was achieved in 3 patients. In these patients there was no peri-interventional stroke or TIA and duplex sonography 6 months postoperatively showed a patent stent without restenosis. In the fourth patient previous attempted transfemoral stenting for symptomatic ICA-stenosis had failed because of a very tortuous CCA. During TCAR, puncture of the CCA was difficult because of atherosclerotic thickening of the vessel wall, furthermore the tip of the guidewire for insertion of the dedicated sheath into the CCA needed to be placed in the CCA rather than in the external carotid artery (ECA) because of ECA occlusion. This led to inadvertent crossing of the stenosis with the guide wire. The procedure was abolished and converted to a conventional carotid endarterectomy. The patient had a perioperative minor stroke with signs of embolization into branches of the medial cerebral artery. He underwent transfemoral intracranial thrombectomy and eventually recovered with only minor deficits. Conclusion Our first experience with TCAR confirmed that patient selection is important: A combination of atherosclerotic disease of the CCA and occlusion of the ECA, both in themselves only relative contraindications to TCAR, led to technical failure and perioperative stroke. With good patient selection TCAR could be performed safely.

Cognitive Impairment Correlates Linearly with Mean Flow Velocity by Transcranial Doppler below a Definable Threshold

Introduction: Low cerebral blood flow can affect cognition in patients with high-grade asymptomatic internal carotid artery stenosis. Current clinical algorithms use stroke risk to determine which patients should undergo revascularization without considering cognitive decline. Although correlations between low-flow and cognitive impairment have been reported, it is not known whether a threshold exists below which such a correlation expresses itself. Such information would be critical in treatment decisions about whether to intervene in patients with high-grade carotid artery stenosis who are at risk for cognitive decline. Objective: To determine how reduced blood flow correlates with lower cognitive scores. Methods: Patients with ≥80% unilateral internal carotid artery stenosis with no history of stroke were recruited from inpatient and outpatient practices at a single, large, comprehensive stroke center. Patients underwent bilateral insonation of middle cerebral arteries with standard 2-Hz probes over the temporal windows with transcranial Doppler. Cognitive assessments were performed by an experienced neuropsychologist using a cognitive battery comprising 14 standardized tests with normative samples grouped by age. Z-scores were generated for each test and averaged to obtain a composite Z-score for each patient. Multivariable linear regression examined associations between mean flow velocity (MFV) and composite Z-score, adjusting for age, education, and depression. The Davies test was used to determine if there was a breakpoint for a non-zero difference in slope of a segmented relationship over the range of composite Z-score values. Results: Forty-two patients with unilateral high-grade internal carotid artery stenosis without stroke were enrolled (26 males, age = 74 ± 9 years, education = 16 ± 3 years). Average composite Z-score was –0.31 SD below the age-specific normative mean (range –2.8 to +1.2 SD). In linear regression adjusted for age, education, and depression, MFV correlated with cognitive Z-score (β = 0.308, p = 0.043). A single breakpoint in the range of composite Z-scores was identified at 45 cm/s. For MFV <45 cm/s, Z-score decreased 0.05 SD per cm/s MFV (95% CI: 0.01–0.10). For MFV >45 cm/s, Z-score change was nonsignificant (95% CI: –0.07 to 0.05). Conclusions: In high-grade, asymptomatic carotid artery stenosis, cognitive impairment correlated linearly with lower flow in the hemisphere fed by the occluded internal carotid artery, but only below a threshold of MFV = 45 cm/s. Identifying a hemodynamic threshold for cognitive decline using a simple, noninvasive method may influence revascularization decision-making in otherwise “asymptomatic” carotid disease.

Predictors of cognitive functioning after carotid revascularization

PurposeHigh-grade carotid stenosis can affect cognition, but the relationship between stenosis correction and cognitive outcome is not fully understood, yet. The aim of this study was to evaluate the predictors of post-operative neurocognitive functioning in patients with symptomatic severe internal carotid artery (ICA) stenosis undergoing carotid endarterectomy (CEA). Materials and methodsPatients with history of transient ischemic attack within the past 6 months and ipsilateral high-grade stenosis of ICA undergoing CEA were prospectively enrolled. Cerebral hemodynamics was assessed by means of the cerebral vasomotor reactivity (CVR) to hypercapnia measured through transcranial Doppler ultrasonography. Coloured Progressive Matrices plus Complex Figure Copy Test, and phonemic plus categorical (ca) Verbal Fluency tests were performed to assess right and left hemisphere cognitive functions, respectively. Cerebral hemodynamics and cognitive functions were assessed before and 6 months after CEA. ResultsOne hundred and eighty-one patients were included. The mean age was 73.2 (6.9) years and 121 (66.9%) were males. At 6 months from CEA, the scores obtained in the cognitive tests exploring the re-vascularized hemisphere's functions and ipsilateral cerebral hemodynamics were improved. At multivariate linear regression analysis, the 6-month change in cognitive performance was inversely associated with age [ß = −0.17, 95% confidence interval (CI) −0.22 to −0.12; p < .001] and CVR value obtained before CEA on the side of ICA stenosis (ß = −6.25, 95% CI −7.40 to −5.10; p < .001). ConclusionsIn patients with symptomatic high-grade ICA stenosis, age and cerebral hemodynamic status before CEA predicted the neurocognitive performance changes after surgical stenosis correction.

Association between gender and stoke recurrence in ischemic stroke patients with high-grade carotid artery stenosis

The association between gender and stroke outcome in patients with high-grade internal carotid artery (ICA) stenosis remains unclear. We investigate gender differences in clinical characteristics and outcomes in ischemic stroke patients with high-grade ICA stenosis. Three-hundred and seventy-two acute ischemic stroke patients with high-grade ICA stenosis were enrolled and followed up for 5 years. Demographic features, vascular risk factors, co-morbidities, and outcomes were compared between male and female genders. Two-hundred and seventy-three (73.4%) patients were males and 99 (26.6%) patients were females. The prevalence of diabetes mellitus and atrial fibrillation was higher in females (P = 0.031 and P = 0.043), whereas the prevalence of smoking was higher in males (P < 0.001). The 5-year mortality rate was not different between males and females (P = 0.437), whereas the 5-year recurrent stroke rate was significantly higher in males (OR, 2.14; 95% CI, 1.22–3.75; P = 0.004). After adjusting for the established clinical predictors of adverse outcomes, the multivariate Cox regression revealed that male gender is a significant predictor of recurrent ischemic stroke (HR, 1.95; 95% CI, 1.19–3.20; P = 0.008). In conclusion, male gender is associated with increased risk of recurrent ischemic stroke in patients with high-grade ICA stenosis during 5-year follow-up. Further prospective trial to assess whether male gender may benefit from more aggressive vascular risk factors control and treatment strategies for stroke prevention is warranted.

Long-Term Outcome of Symptomatic Patients Undergoing Hybrid Revascularisation for Extracranial Carotid Artery Tandem Stenosis

Carotid tandem lesions are a multilevel significant (>50%) atherosclerotic disease involving both the internal carotid artery (ICA) and either the ipsilateral common carotid artery (CCA) or the innominate artery (IA). These lesions may be challenging to treat. Current guidelines offer no definitive recommendation on the optimal treatment algorithm. The aim of this analysis was to assess the long-term outcome of patients undergoing surgical revascularisation for tandem lesions. In two centres, consecutive patients who underwent carotid endarterectomy (CEA) for a symptomatic carotid artery stenosis between 2003 and 2017 were screened retrospectively for the presence of a carotid artery tandem lesion. All eligible patients were treated by a hybrid approach, consisting of retrograde stenting of the proximal CCA or IA followed by CEA. All patients had a yearly clinical check up including duplex ultrasound. The primary outcome was occurrence of any stroke, death, myocardial infarction (MI), or transient ischaemic attack (TIA) within 30 days. Secondary outcomes were any stroke, death, MI, or TIA and occurrence of restenosis ≥50% during follow up. Sixteen of 2368 symptomatic patients were included. Besides a high grade ICA stenosis, patients had a significant ipsilateral stenosis of the CCA (n=13) or IA (n=3). Within 30 days there were no deaths, strokes, or TIAs. Two patients had a clinical MI. During a median follow up of 73 (interquartile range 22-85) months, three patients died. One patient developed a symptomatic restenosis of the ICA (ipsilateral TIA). Two patients (without restenosis) developed an ipsilateral stroke and a MI. In this small case series, hybrid revascularisation of carotid tandem lesions in symptomatic patients seems feasible and safe. Long-term data show a relatively high number of any adverse events. These surgical outcomes need to be offset against the natural course in patients with a symptomatic carotid tandem lesion.

The Relevance of Vascular Endothelial Growth Factor, Hypoxia Inducible Factor-1 Alpha, and Clusterin in Carotid Plaque Instability

Stroke is one of the leading causes of morbidity and mortality. Thromboembolism, as a major cause of carotid artery-related stroke, can be caused by plaque rupture which is associated with neoangiogenesis within the carotid plaque. We sought to investigate a possible correlation between angiogenesis-related factors and preoperative neurological manifestations in patients with internal carotid artery stenosis, for a better understanding of thromboembolism in internal carotid artery stenosis-related stroke. This study included 54 patients (asymptomatic, n = 20 and symptomatic, n = 34) undergoing carotid endarterectomy for high-grade internal carotid artery stenosis. In the retrieved carotid plaques, angiogenesis-related factors (vascular endothelial growth factor [VEGF], hypoxia inducible factor-1 alpha [HIF-1α], and Clusterin) were measured by immunohistochemistry and quantified by real-time polymerase chain reaction. We demonstrated the expression of VEGF, HIF-1α, and Clusterin by endothelial cells and smooth muscle cells in the carotid plaques. Noteworthy, mRNA VEGF levels were .7-fold higher in symptomatic patients (P = .017) compared to asymptomatic patients. In contrast, mRNA Clusterin levels were 1.8-fold lower (P = .021). Levels of mRNA HIF-1α were 1.5-fold higher in asymptomatic patients, but no statistical significance was reached between the 2 groups. Our results show an association between VEGF and Clusterin and neurological symptoms of patients with high-grade carotid artery stenosis.

Association Between Total Cholesterol and 5 year Mortality in Patients with Carotid Artery Stenosis and Poststroke Functional Dependence

Background: Aggressive lipid-lowering treatment reduces the risk of cardiovascular events, but remains controversial in stroke patients. We investigate the influence of total cholesterol level on 5-year outcomes of ischemic stroke patients with high-grade internal carotid artery (ICA) stenosis and poststroke functional dependence.Methods: One-hundred and ninety-six acute ischemic stroke patients with high-grade ICA stenosis and modified Rankin Scale score ≥ 3 upon discharge were enrolled and prospectively observed for 5 years. Patients were divided into 2 groups according to total cholesterol level at admission: ≥200 mg/dL or <200 mg/dL. Demographic features, vascular risk factors, co-morbidities, and outcomes were compared between the 2 groups. Results: 117 (59.7%) patients had higher and 79 (40.3%) patients had lower total cholesterol levels. The prevalence of older age and atrial fibrillation was significantly higher in patients with lower total cholesterol; the prevalence of diabetes mellitus was higher in patients with higher total cholesterol. After adjusting for the established clinical predictors of adverse outcomes, the multivariate Cox regression revealed that lower total cholesterol level is a significant predictor of 5-year mortality (HR (hazard ratio) = 1.88, 95% CI (confidence interval) = 1.09-3.23, P = .023). Conclusions: Lower total cholesterol level is associated with increased risk of 5-year mortality in ischemic stroke patients with high-grade ICA stenosis and post-stroke functional dependence. Aggressive treatment of hyperlipidemia should be carefully considered in these patients although it could reduce the risk of atherosclerotic cardiovascular diseases and stroke recurrence in some stroke patients.

The stronger one-sided relative hypoperfusion, the more pronounced ipsilateral spatial attentional bias in patients with asymptomatic carotid stenosis

Patients with asymptomatic, high-grade internal carotid artery stenosis often suffer from subtle cognitive impairments with unclear underlying neuro-cognitive mechanisms. Thus, we hypothesized that stenosis-related unilateral cerebral hypoperfusion leads to an ipsilateral attentional bias; 22 patients with asymptomatic, one-sided high-grade carotid stenosis and 24 age-matched healthy controls underwent pseudo-continuous arterial spin labeling to assess brain perfusion in the territory of the carotid arteries. Furthermore, a parametric assessment of attention functions was carried out on the basis of the computational Theory of Visual Attention. Both patients' perfusion and spatial attention were significantly more lateralized than those of healthy controls. Critically, both asymmetry indices were significantly correlated in patients, i.e. the stronger one-sided relative hypoperfusion, the stronger ipsilateral bias of attention. This association was specifically pronounced in parietal cortices and independent of white matter hyperintensities as a surrogate for cerebrovascular brain damage. Results provide evidence for a link between lateralized hypoperfusion and lateralized attentional weighting in asymptomatic, high-grade carotid stenosis. Data suggest that lateralized hypoperfusion with simultaneous spatial attentional bias might serve as a potential therapeutic target in one-sided carotid stenosis.

CAR 10. Endarterectomy for Acute Symptomatic Thrombotic Occlusion of the Entire Extracranial Internal Carotid Artery: A Case Report

We report the case of a 60-year-old woman who was admitted with a sudden onset of numbness of the left upper extremity. Two weeks before admission, the patient presented with a right hemispheric transient ischemic attack and temporary right facial paresis. Duplex ultrasound and magnetic resonance (MR) angiography revealed an occlusion of the right internal carotid artery (ICA) as well as a high-grade stenosis of the left ICA with patency of the cerebral arteries (middle cerebral artery [MCA]). A cranial computed tomography scan showed a small hypodense lesion of the right hemisphere and several lacunar infarctions without signs of intracranial bleeding. An exploration of the right carotid bifurcation was performed, and an atherosclerotic plaque at the carotid bifurcation with a fresh clot downstream was found. Thrombectomy was performed using a 2F balloon catheter, resulting in a sufficient backflow from the ICA. In addition, thromboendarterectomy with patch plasty was performed. On the final intraoperative angiogram, the entire right ICA and the downstream intracranial vessels were patent. Intraoperative duplex ultrasound confirmed a sufficient hemodynamic profile without major turbulences. The postoperative MR angiogram confirmed patency of the ICA with an undisturbed perfusion of the right hemisphere. The postoperative course was uneventful; no neurologic symptoms occurred, and she was discharged on postoperative day 8. Six weeks later, the left ICA stenosis (North American Symptomatic Carotid Endarterectomy Trial [NASCET] 90%) was treated successfully by conventional thromboendarterectomy. During follow-up of 61 months, no neurologic or cardiac events occurred. A recurrent ICA stenosis was not detected. Comparing the perfusion of the right MCA with the preoperative MR angiogram, we conclude that a sufficient blood supply to the right MCA could probably not have been achieved by a simple left-sided carotid thromboendarterectomy. Whereas chronic ICA occlusion is generally accepted as a condition not suitable for extracranial reconstruction, our patient profited from revascularization as she suffered from an acute occlusion on top of a chronic stenosis. It remains uncertain which occluded artery should be explored and, specifically, at what time. In symptomatic patients, exploration of the ICA and carotid bifurcation might be justified to restore blood flow and to prevent a severe stroke event.

Association Between Stroke Severity and 5-Year Mortality in Ischemic Stroke Patients with High-Grade Stenosis of Internal Carotid Artery

BackgroundThe clinical presentations and outcomes of patients with high-grade stenosis of internal carotid artery (ICA) are highly variable. We investigate the influence of different stroke severity on outcomes of ischemic stroke patients with high-grade stenosis of ipsilateral ICA. Methods372 acute first-ever ischemic stroke patients with high-grade stenosis (70%-99%) or occlusion of ipsilateral ICA were enrolled and followed up for 5years. Stroke severities of the enrolled patients were grouped according to the Oxfordshire Community Stroke Project classification system as total anterior circulation infarcts (TACI) or non-TACI. Demographic features, vascular risk factors, comorbidities, and outcomes were compared between the 2 groups. ResultsA total of 71 patients (19.1%) were presented with TACI. Of laboratory data, the values of white blood cell count and high-sensitivity C-reactive protein were significantly higher in patients with TACI (P = .008 and P = .003, respectively). Of clinical course, the occurrence of initial impaired conscious, stroke-in-evolution, pneumonia, gastrointestinal bleeding, and urinary tract infection were significantly higher in patients with TACI. The prevalence of dependent functional status was higher in patients with TACI. Multivariate Cox regression revealed that TACI is a significant predictor of 5-year all-cause mortality in first-ever ischemic stroke patients with high-grade stenosis of ipsilateral ICA (HR [hazard ratio] = 3.66, 95% confidence interval = 2.23-6.00, P < .001). ConclusionsTACI is associated with increased risk of 5-year mortality in ischemic stroke patients with high-grade stenosis of ipsilateral ICA. Intensive medical treatment for stroke prevention in patients with severe carotid artery stenosis is warranted.

Coexistent Ipsilateral Internal Carotid Artery Occlusion and Cerebral Venous Thrombosis in Hepatitis C.

A 58-year-old male, known to have hepatitis C virus (HCV), presented with intermittent headaches and left-sided sensorimotor symptoms. There were no focal neurological deficits on examination. Electrocardiogram was unremarkable. Computed tomography angiography head and neck displayed extracranial right internal carotid artery occlusion. Magnetic resonance imaging showed right cortical vein thrombosis, with hemorrhagic infarction. Echocardiography with bubble study was unremarkable. Hypercoagulable workup was significant for protein S deficiency. He was treated with warfarin for 6 months. Repeat protein S levels remained low 9 months later. The coexistence of arterial and venous thrombotic events gives rise to a limited differential. In this case, it may be related to chronic HCV infection. The underlying pathogenesis is not clear; however, it is possible the patient had chronic high-grade internal carotid artery stenosis, which occluded leading to his presenting symptoms. The cortical vein thrombosis is likely an incidental finding here. The extent by which HCV contributed to the cerebral thrombosis and carotid artery occlusion in our case is not clear; however, the hypercoagulable and atherosclerotic properties of the virus cannot be disregarded. The virus can promote carotid atherosclerosis and cerebral venous thrombosis as well as other venous and arterial thromboembolic events. Furthermore, HCV is associated with impaired venous flow and procoagulant properties, which can fuel a hypercoagulable state. Also of note cirrhosis is associated with protein S deficiency. We recommend considering an underlying hypercoagulable state including both arterial and venous thrombosis in HCV infection.