Symptomatic Extracranial Internal Carotid Artery Research Articles

Risk of new cerebral ischemic events in patients with symptomatic internal carotid artery stenosis while awaiting carotid stent placement.

Although there is an emphasis on performing carotid artery stent (CAS) placement within 2weeks after index event of transient ischemic attack (TIA) or minor stroke in patients with significant extracranial internal carotid artery (ICA) stenosis, the risks and characteristics of recurrent cerebral ischemic event while waiting for CAS placement are not well defined. We analyzed patients admitted to our institution over a 45-month period with symptomatic extracranial ICA stenosis. We identified any new cerebral ischemic events that occurred between index cerebral or retinal ischemic event and CAS placement and categorized them as TIA and minor or major ischemic strokes. We calculated the risk of new ipsilateral cerebral ischemic events between index cerebral or retinal ischemic event and CAS placement. The mean age of 131 patients analyzed was 67years (range: 47-94 years; 92 were men), and 94 and 37 patients had 70%-99% and 50%-69% severity of stenosis, respectively. The mean and median time intervals between index cerebral or retinal ischemic event and CAS performance were 28 (standard deviation [SD] 30) and 7 (interquartile range 33) days, respectively. A total of 9 of 131 patients (6.9%, 95% confidence interval 2.5%-11.2%) experienced new cerebral ischemic events over 3637 patient days of observation. The risk of new ipsilateral cerebral ischemic events was 2.5 per 1000 patient days of observation. We estimated the risk of new ipsilateral cerebral ischemic events in patients with ICA stenosis ≥50% in severity while waiting for CAS placement to guide appropriate timing of procedure.

Radiological Spectrum of Pseudoaneurysms After Extracranial Internal Carotid Artery Dissection

Radiological Spectrum of Pseudoaneurysms After Extracranial Internal Carotid Artery Dissection

A Protocol for Carotid Artery Stenting in COVID Times. A Single Canadian Centre Experience.

The COVID-19 pandemic has resulted in huge disruption to healthcare delivery worldwide. There is a need to balance the urgent needs of the neurovascular patient population with the desire to preserve critical inpatient hospital capacity. It is incumbent on neurointerventionalists to advocate for their patients to minimise future disability. Patients still require semiurgent carotid revascularisation after ischaemic embolic events. We present a review of a novel protocol for expediting patient flow through the carotid stenting process, in accordance with government directives to minimise nonessential inpatient admissions, ensure its efficacy, and evaluate its safety. We also evaluate the literature regarding complications with attention to the timing of these related to the procedure. A retrospective review of 45 consecutive carotid stenting cases performed at London Health Sciences Centre between March 2020 and March 2021 for symptomatic extracranial internal carotid artery stenosis utilising a default same-day discharge policy was performed. Complications were plotted as a function of time. Twenty-four patients underwent carotid artery stenting with same-day discharge and 21 patients underwent stenting with an overnight inpatient stay. A single stent occlusion occurred 27 h post stenting. Simple modification of protocol for symptomatic carotid artery stenting during the COVID-19 outbreak with radial access as first approach appears to provide safe, efficacious care.

Abstract P260: Ischemic Strokes on Direct Oral Anticoagulants

Introduction: The objective of our study was to identify the underlying causes of acute ischemic strokes (AIS) in patients prescribed direct oral anticoagulants (DOACs). Methods: This is a retrospective study of patients presenting to a large urban comprehensive stroke center from December 1, 2019 to May 31, 2020 who were prescribed DOACs at the index event. Two board-certified vascular neurologists independently reviewed medical charts including patient baseline characteristics, laboratory results, stroke mechanism, and patient-reported adherence. DOAC “failure” was defined as AIS occurring in the setting of self-reported adherence to the FDA-indicated dosing regimen. Results: Of 302 AIS patients admitted during the study period, 18 (6.0%) patients had AIS while on DOACs. Median age was 82 (IQR 72, 86) years, 9 (50%) were black and 14 (78%) were female. Eight patients (44%) presented within the IV Alteplase window and 5 (28%) patients presented with large vessel occlusion. At the time of stroke, 13 (72%) patients were on apixaban, 4 (22%) were on rivaroxaban and 1 (6%) on dabigatran. Atrial fibrillation (mean CHADS-VASc score 4.7) was the most common indication for DOAC (72%), followed by deep venous thrombosis (17%), and embolic stroke (11%). The most frequent causes of AIS on DOACs were underdosing in patients ≥ 80 years (n=6), known active malignancy (n=5), and non-adherence (n=4). The remaining cases included procedure-related discontinuation of the DOAC (n=1), symptomatic extracranial internal carotid artery stenosis (n=1), and unknown cause (n=1). Overall, the frequency of DOAC “failure” was 39%. In 6 (33%) patients, the initial anticoagulant was switched to an alternative anticoagulant at discharge. Conclusion: In this cohort of patients who had AIS while on DOAC therapy, 39% of cases were attributed to DOAC “failure” and primarily occurred in patients with active malignancy. Underdosing in the elderly and non-adherence remained the leading cause of AIS in patients on DOAC. Our findings highlight the importance of accurate dosing in the elderly and reinforcing adherence to medications. Further studies are needed to understand the role of DOACs in patients with active malignancy.

Clinical Review: Best Medical Therapy Superior to Carotid Endarterectomy in Secondary Stroke Prevention in Symptomatic Extracranial Internal Carotid Artery Stenosis of 50-69%

Transient ischemic attacks (TIA) are known as a herald to an impending stroke or another TIA. Past medical assessment of the risk of stroke following a transient ischemic attack (TIA) commonly quoted a 1-2% risk of stroke at seven days following a TIA and 2-4% risk of stroke at one-month following a TIA

A case of symptomatic extracranial internal carotid artery aneurysm

A case of symptomatic extracranial internal carotid artery aneurysm

Acute symptomatic extracranial internal carotid occlusion - natural course and clinical impact.

Background: To assess the vascular and clinical course of acute symptomatic extracranial internal carotid artery (ICA) occlusion. Patients and methods: Patients with an acute ischemic event in the anterior circulation and corresponding extracranial ICA occlusion at CT angiography and/or color-coded duplex sonography underwent recurrent duplex follow-up for detection of spontaneous recanalization. Stroke recurrence and functional outcome 4.5 months after the ischemic index event assessed by modified Rankin scale served as secondary outcome parameters. Results: 133 patients (91 men, mean age 62.3years, SD 10.8) demonstrated symptomatic occlusion of the extracranial ICA with open intracranial ICA and open middle cerebral artery and were followed-up for spontaneous recanalization. Twenty-eight recanalized spontaneously, 25 to high-grade focal stenosis within 12 days, revealing an early cumulative recanalization rate of 23%. Detection of recanalization was independently associated with de novo dual anti-platelet therapy (adjusted odds ratio [OR], 3.24; 95% confidence interval [CI], 1.34 to 7.80). Ischemic recurrence occurred in 16 patients, of which 10 deemed to be embolic and 5 hemodynamic. Spontaneous ICA recanalization and an exhausted cerebrovascular reserve in the hemisphere distal to the occluded ICA were both independently associated with the occurrence of a recurrent ischemic event at Cox regression. An increasing NIHSS score at admission, a decreasing middle cerebral artery flow velocity and an ischemic recurrence independently predicted poor outcome (modified Rankin scale 3 to 6) in multivariate analysis. Conclusions: Acute symptomatic extracranial ICA occlusion is an unstable condition with frequent spontaneous recanalization to severe stenosis and early embolic stroke recurrence, demanding appropriate prevention especially in those patients with only mild deficit.

Extracranial internal carotid artery occlusion-a prospective study

Backround Symptomatic and asymptomatic occlusions of the extracranial internal carotid artery (EICA) is linked with high risk of stroke event. Objective This study aimed to compare symptomatic and asymptomatic occlusion of EICA by carotid duplex ultrasonography (CDU) and determine the risk factors of atherosclerotic plaques and identify the clinical features. Methods This was a hospital based prospective study, conducted at the Third General Central Hospital , between 2015- 2017. Totally, 492 ischemic stroke and complained before symptoms of transient ischemic attack patients aged below and above 50 years of both sexes were included in the CDU study from which 56 cases were determined total EICA occlusions. RESULTS: Of these 56 (11.38%) patients with complete occlusion of EICA, men were predominant (81.6%) with mean age of 58.0±14.8 years and sex ratio 2.5:1. Symptomatic EICA was detected in 49 (87.5%) cases with mean age of 57.5±17.6 while asymptomatic EICA was determined in 7 cases (12.5%) with mean age of 48.3±15.3 years. The most frequent identified risk factors were hypertension (87.5%), smoking (63.6%) and coronary artery disease (69.2%)(p

Abstract WP39: Radiographic Classification of ICA Occlusions Predicts Clinical Fluctuation and Post-Stenting Hemorrhage Risk

Introduction: The optimal treatment strategy for symptomatic extra-cranial internal carotid artery (ICA) occlusion remains unknown. A radiographic classification of ICA occlusions has been proposed to help predict technical feasibility and the risk of complications with revascularization. The classification includes 4 main types (A-D) based on the morphology of the ICA stump (A having a tapered stump, B having a non-tapered stump, C and D having no stump) as well as the presence of reconstitution of flow in the intracranial ICA (C having reconstitution of the ICA within the cavernous and/or petrous segment and D having no reconstitution). In this study, we assess the predictive value of this classification scheme in understanding clinical phenotype and post-stenting complications. Methods: A retrospective review of a prospectively maintained database was conducted of clinical and radiological data from patients undergoing attempted angioplasty and stenting of complete symptomatic cervical ICA occlusion without tandem intracranial occlusion. Results: Seventy-two patients were included in the study, with a mean age of 63 years and 36% female gender. Classification type was as follows: 36% (type A), 25% (type B), 32% (type C) and 7% (type D). Revascularization was successful in 66/72 (92%) of patients. Clinical fluctuation prior to revascularization was most frequent in type A occlusions (p=0.02) and least frequent in type B occlusion (p=0.02). Only 8% of patients had peri-procedural intracerebral hemorrhage and the highest frequency occurred in group D (p=0.05). In a multivariate analysis, lower age, lower pre-treatment NIH Stroke Scale and favorable Alberta Stroke Program Early CT Score were predictors of higher modified Rankin Scale at 3 months (p=0.025, 0.004, 0.049, respectively). Conclusions: Radiographic classification of ICA occlusions can help classify patient phenotypes and potentially predict the technical safety of angioplasty and stenting. Prospective studies are warranted to confirm these findings.

Comparison of Clinical Characteristics among Subtypes of Visual Symptoms in Patients with Transient Ischemic Attack: Analysis of the PROspective Multicenter registry to Identify Subsequent cardiovascular Events after TIA (PROMISE-TIA) Registry

A transient visual symptom (TVS) is a clinical manifestation of transient ischemic attack (TIA). The aim of this study was to investigate differences in clinical characteristics among subtypes of TVS using multicenter TIA registry data. Patients with TIA visiting within 7 days of onset were prospectively enrolled from 57 hospitals between June 2011 and December 2013. Clinical characteristics were compared between patients with 3 major subtypes of TVS (transient monocular blindness [TMB], homonymous lateral hemianopia [HLH], and diplopia). Of 1365 patients, 106 (7.8%) had TVS, including 40 TMB (38%), 34 HLH (32%), 17 diplopia (16%), and 15 others/unknown (14%). Ninety-one patients with 1 of the 3 major subtypes of TVS were included. Symptoms persisted on arrival in 12 (13%) patients. Isolated TVS was significantly more common in TMB than in HLH and diplopia (88%, 62%, and 0%, respectively; P < .001). Duration of symptoms was shorter in patients with TMB than those with HLH (P = .004). The ABCD2 score was significantly lower in patients with TMB compared with those with HLH and diplopia (median 2 [interquartile range 2-3] versus 3 [2-4] and 4 [2-5], respectively; P = .005). Symptomatic extracranial internal carotid artery stenosis or occlusion was seen in 14 (16%) patients, and was more frequent in TMB than in HLH and diplopia (28%, 9%, and 0%, respectively; P = .015). TVS was an uncommon symptom in our TIA multicenter cohort. Some differences in clinical characteristics were found among subtypes of TVS.

Comparison of Best Medical Management with Carotid Intervention Procedures in the Prevention of Stroke Recurrence in Patients with Symptomatic Internal Carotid Artery Stenosis.

Background:As per the current recommendations, carotid interventional procedures (carotid endarterectomy/carotid artery stenting) are considered superior to medical management in reducing the stroke recurrence in patients with symptomatic extracranial internal carotid artery (ICA) stenosis.Objective:The objective of this study is to compare the best medical management with carotid interventional procedures in the prevention of stroke recurrence in the patients with symptomatic extracranial ICA stenosis.Materials and Methods:This was a parallel, prospective, two-arm, open-label, observational study. Participants were selected consecutively and prospectively among patients from Outpatient and Inpatient Departments of Neurology at Nizam's Institute of Medical Sciences, Hyderabad, Telangana, India. The study period was from January 2012 to December 2017.Results:Of 150 patients with symptomatic extracranial ICA stenosis of ≥50%, 100 preferred best medical management (m = 75, f = 25) and 50 (m = 37, f = 13) opted for carotid intervention. The mean age of the patient cohort was 59.8 ± 12.7. Follow-up was done at regular intervals from 3 months to 1 year. In the medical group, the recurrence occurred in 10 patients; 4 (40%) within 6 months, 5 (50%) within 6–12 months, and 1 (10%) after 1 year. In the intervention group, the recurrence occurred in 6 patients; 5 (83%) within the first 6 months and 1 (17%) within 6–12 months.Conclusions:Overall, there was no statistically significant difference in the rate of recurrence between the best medical management and the carotid interventional procedures.

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.

Computed Tomography Perfusion Imaging in the Selection of Acute Stroke Patients to Undergo Emergent Carotid Endarterectomy

Severe acute stroke patients with critical carotid stenosis or occlusion without intracranial thrombus typically do not undergo emergent carotid thromboendarterectomy (CEA) because of the risk of reperfusion-related intracranial hemorrhage. Past studies have not consistently demonstrated benefit of early operative intervention. Cerebral computed tomography (CT), cervical and cerebral CT angiography (CTA), and cerebral CT perfusion (CTP) imaging may identify a subset of acute stroke patients without intracranial thrombus who may benefit from emergent CEA. Acute stroke patients underwent unenhanced brain CT imaging to exclude pathology that would contraindicate emergent therapy. Emergent CTAs of the intracranial and extracranial vessels were utilized to identify patients who presented with stroke symptoms based on the presence of isolated extracranial carotid disease in the absence of intracranial thromboembolism. CTP was then used to assess the extent of potentially reversible cerebral ischemia (penumbral tissue). Patients with isolated extracranial carotid lesions with significant reversible ischemia in the absence of large areas of irreversible cerebral damage underwent emergent CEA to salvage ischemic penumbra. In 1 year, 3 patients presented with large acute strokes in which CTA disclosed symptomatic extracranial internal carotid artery preocclusive or occlusive lesions without intracranial thromboembolic occlusions. CTP indicated a large area of ischemic penumbra with limited permanent injury. Mean age, time to presentation, and National Institutes of Health stroke score (NIHSS) were 66 years, 4.2 hr, and 19.3. All patients underwent emergent CEA with cervical carotid thrombectomy. Average time from stroke symptom onset to revascularization was 12.5 (range 5.9-19.0) hr. There were no perioperative deaths. At day 5, the mean NIHSS decreased to 7.6 and at day 30 was 4.7. The modified Rankin scale score dropped from a poststroke, preoperative level of 5 to 2.3 by day 30. Emergent CEA should be considered in patients presenting with large acute strokes based on favorable CT, CTA, and CTP findings. Emergent clot localization and physiological assessment of brain "tissue at risk" relative to irreversible cerebral infarction using CT, CTA, and CTP is now available. Utilization of this information by an experienced stroke team of neurologists, radiologists, and surgeons may aid in the recognition of a select group of patients in which emergent CEA may drive to improved outcomes.

Carotid Revascularization: An Update

Symptomatic extracranial internal carotid artery stenosis poses a high short-time risk of ischemic cerebral stroke, as high as 20% to 30% in the first three months. Timely performed carotid endarterectomy (CEA) has been shown to be highly effective in reducing this risk although, in recent years, there has been great interest in replacing this procedure with less invasive carotid angioplasty and stenting (CAS). In this update we review recent studies and provide recommendations regarding the indications, methods and timing of surgical intervention as well as the anaesthetic management of CEA, and we report on recently published randomized controlled trials comparing CEA to CAS. We also provide recommendations regarding the sometime neglected but important medical management of patients undergoing carotid intervention, including antithrombotic and antihypertension therapy, lipid lowering agents, assistance with smoking cessation, and diabetes control.

Common Carotid Artery Stenosis and Amaurosis Fugax

Clinical characteristics of common carotid artery (CCA) stenosis have been reported relatively rarely, compared with those of internal carotid artery (ICA) stenosis. The current retrospective study aimed to clarify the symptomatology of CCA stenosis. Summarized records of patients admitted were reviewed to identify patients with CCA stenosis or extracranial ICA stenosis. Clinical histories and neurologic symptoms were identified and analyzed. CCA stenosis was present in 12 patients (symptomatic, n = 8; asymptomatic, n = 4). Among symptomatic patients, 4 (50%) had amaurosis fugax. Among 137 patients with symptomatic extracranial ICA stenosis, amaurosis fugax occurred in 9 patients (6.6%). Frequency of amaurosis fugax was significantly higher in CCA stenosis than in ICA stenosis. Patients with CCA stenosis may be susceptible to transient hemodynamic insufficiency of the retina as a result of simultaneous reductions in blood supplies from both the external carotid artery and the ICA.

RECANALIZATION OF A SYMPTOMATIC EXTRACRANIAL INTERNAL CAROTID ARTERY NEAR OCCLUSION WITH PROXIMAL AND DISTAL PROTECTION

To describe a novel approach to recanalizing symptomatic extracranial internal carotid artery near occlusion using proximal and distal emboli protection devices. Patients presenting with symptomatic extracranial internal carotid artery near occlusion who underwent endovascular recanalization between October 2004 and July 2005 were included in this study. During these procedures, a 9-French Concentric Balloon Guide Catheter (Concentric Medical, Mountain View, CA) was advanced into the common carotid artery proximal to the site of occlusion. During the prestent angioplasty of the lesion, the proximal balloon was inflated and aspiration was performed. After initial angioplasty and before stent placement, a distal filter protection device was placed in the distal internal carotid artery. Stent placement and repeat angioplasty were performed with both protection devices active. All patients were placed on dual antiplatelet therapy. There were four patients treated with a mean age of 74 years; three of these four patients were men. All patients had signs of ischemia and carotid occlusion or near occlusion on noninvasive imaging. Three right internal carotid arteries were treated. All patients were successfully recanalized. No procedurally related complications or deaths occurred. This series demonstrates the feasibility of recanalization of symptomatic carotid artery occlusion or near occlusion using proximal and distal emboli protection devices. Such an approach may provide an added level of safety during carotid recanalization procedures.

Safety of latest-generation self-expanding stents in patients with NASCET-ineligible severe symptomatic extracranial internal carotid artery stenosis.

Patients with symptomatic extracranial internal carotid artery stenosis (> or =70%) benefit from carotid endarterectomy when compared with medical management. However, independent risk factors can significantly increase the combined stroke and death risk after carotid endarterectomy. Carotid angioplasty and stenting (CAS) is a therapeutic option in patients who are otherwise at high risk or ineligible for carotid endarterectomy. Previous-generation self-expanding stents were hampered by length foreshortening, which limited their application in multifactorial occlusive extracranial internal carotid artery stenosis. This is a single-center, prospective, open-label, safety study of CAS with the latest-generation self-expanding stents in patients with extracranial internal carotid artery symptomatic stenosis (> or =70%). All patients included were adjudicated to be ineligible for carotid endarterectomy by a vascular surgeon and/or a neurologist according to the exclusion criteria. Primary adverse events included death and all strokes (ipsilateral and contralateral). Secondary adverse events included transient ischemic attack, myocardial infarction, stent thrombosis, need for reintervention, and presence of hematomas. All adverse events were recorded at 24 hours, 30 days, and 6 months after CAS. Between June 1, 2001, and January 30, 2003, 23 consecutive patients (14 women and 9 men; mean age, 65 years; age range, 48-85 years) underwent 24 extracranial CAS procedures with the latest-generation self-expanding stents. All patients had one or multiple criteria for ineligibility according to the North American Symptomatic Carotid Endarterectomy Trial. Extracranial CAS was successful in all patients, with average residual stenosis of less than 20%. One patient (4%) experienced a stroke by the 30-day periprocedure examination. The total number of primary adverse events at 6 months after CAS was 2 strokes (9%), 1 of which was contralateral to the stent placement; there were no deaths. Twenty-two patients were asymptomatic at 6 months, with a modified Rankin scale score of 1 or less. Of the 2 patients who had a stroke, 1 had a follow-up modified Rankin scale score of 3. Extracranial CAS with the latest-generation self-expanding stents is a valid alternative treatment in high-risk or North American Symptomatic Carotid Endarterectomy Trial-ineligible patients.