Internal Carotid Artery Disease Research Articles

Carotid artery disease progression and related neurologic events after carotid endarterectomy

During the last decade, there has been a dramatic improvement in best medical treatment for patients with vascular disease. Yet, there is a paucity of contemporary long-term data for restenosis and contralateral internal carotid artery (ICA) progression. This study assessed ipsilateral and contralateral disease progression and cerebrovascular events after carotid endarterectomy (CEA). A consecutive cohort of CEAs between January 1, 2000, and December 31, 2010, was retrospectively analyzed. End points were restenosis ≥50% and ≥70%, contralateral carotid disease progression (50%-69%, 70%-99%, or occlusion) and stroke. Survival analysis and Cox regression models were used to assess the effect of baseline predictors. During the 11-year study period, 1639 patients underwent 1782 CEAs (50.0% patch closure, 23.9% primary closure, 26.1% eversion, and 2.5% combined with coronary artery bypass grafting). The combined stroke/death rate was 2.6% overall and 1.8% in the asymptomatic cohort. The rate of restenosis ≥50% at 2, 5, and 10years was 8.5%, 15.6%, 27.2%, and the rate for restenosis ≥70% was 3.4%, 6.5%, 10.2%, respectively. Restenosis ≥50% was predicted by hypertension (hazard ratio [HR], 2.09; P= .027), female gender (HR, 1.43; P= .042), and younger age (≤65years; HR, 1.56; P= .016), but not by statins, surgical technique, symptoms, or other baseline risk factors. Restenoses remained asymptomatic in 125 of 148 (84.5%). Progression of contralateral ICA disease at 2, 5, and 10years was estimated at 5.4%, 15.5%, and 46.8%, respectively. Contralateral progression was only predicted by smoking (HR, 1.74; P=.008). The stroke rate in patients with disease progression of the contralateral ICA was not different compared with those without progression (7.0% vs 3.3%; P= .063). Any-stroke rates at 2, 5, and 10years were 4.6%, 7.3%, and 15.7%, respectively. Predictors were symptomatic lesion (HR, 1.48; P= .039), renal insufficiency, defined as a glomerular filtration rate (GFR) of 30 to 59 vs<30mL/min/1.73m2 (HR, 0.34; P= .009) or GFR ≥60 vs GFR<30mL/min/1.73m2 (HR, 0.55; P= .109), and statin use (HR, 0.59; P= .006). Restenosis or contralateral disease progression after CEA, to a level that might warrant consideration for treatment, is very low. The potentially associated stroke rates are also very low and not clearly related to disease progression. With the exception of the postoperative duplex, surveillance within short intervals of<1 or 2years cannot be justified.

Abstract WP233: Validation of Multi-parametric Ultrasonography Criteria With Catheter Angiography in Internal Carotid Artery Disease: a Multicenter Study

Introduction: Novel multi-parametric criteria for duplex ultrasonography (DUS) grading of extracranial internal carotid artery (ICA) steno-occlusive disease have been recently introduced by the German ultrasound expert panel (DEGUM). We sought to determine diagnostic accuracy of the DEGUM criteria against the gold standard catheter angiography. Methods: We prospectively enrolled consecutive patients who routinely underwent diagnostic or therapeutic catheter angiography of the extracranial carotid arteries in four German study sites. Internal carotid artery disease was graded according to the DEGUM multi-parametric criteria for DUS. On angiography, extracranial ICA disease was graded using the NASCET approach. Ultrasonography and endovascular raters were blinded to clinical data and any other imaging modalities. To correspond to clinically relevant NASCET groups, all stenosis measurements were stratified into ranges: normal, mild (1-49%), moderate (50-69%), severe (70-99%) and occlusion. Results: We studied 130 patients who underwent both DUS and catheter angiography for assessment of carotid arteries (mean age, 64±11 years; 67% men; median time between DUS and angiography, 1 day [interquartile range, 2.5]). To date, fifty-two carotid artery pairs were independently rated and available for comparative analysis. Compared with catheter angiography, DUS had the following positive (PPV) and negative predictive values (NPV): PPV 50% and NPV 72% (3 true positive, 3 false positive, 33 true negative, 13 false negative) for detection of moderate, and PPV 57% and NPV 77% (20 true positive, 15 false positive, 13 true negative, 4 false negative) for detection of severe stenosis. Conclusions: Our preliminary data indicate that the novel DEGUM multi-parametric ultrasonography criteria do not eliminate the need for a confirmatory test for identification of clinically relevant grades of extracranial ICA disease.

Abstract WMP110: Improvement in Cortical Versus Subcortical Perfusion After Superficial Temporal Artery- Middle Cerebral Artery (MCA) Bypass in Patients With Severe Stenosis of Intracranial Carotid and MCA

Background and Objective: The role of superficial temporal artery-middle cerebral artery (STA-MCA) bypass in patients with symptomatic intracranial steno-occlusive disease has been evaluated scarcely. We have recently reported the improvement in clinical and various cerebral hemodynamic parameters after STA-MCA bypass surgery for severe steno-occlusive disease of intracranial internal carotid (ICA) or middle cerebral artery (MCA) and impaired cerebral vasodilatory reserve (CVR). Using acetazolamide challenged hexamethylpropyleneamine-oxime single-photon emission computed tomography (HMPAO-SPECT), we evaluated the differential improvement in metabolic perfusion in cortical and subcortical structures after STA-MCA bypass surgery. Methods: Patients with severe steno-occlusive disease of intracranial ICA or MCA underwent transcranial Doppler (TCD) for CVR assessment using breath-holding index (BHI). Patients with impaired BHI (&lt;0.69) were further evaluated with acetazolamide-challenged SPECT and STA-MCA bypass surgery was offered to patients with impaired CVR on SPECT. All patients underwent SPECT at 4±1 months. Using automated image analyzer, we evaluated differences in metabolic perfusion in cortical and subcortical regions. Results: Of the 126 patients (80 male, mean age 56yrs; range 23-78yrs) that fulfilled our inclusion criteria, 84 (67%) showed impaired CVR on SPECT. Fifty (60%) of them underwent STA-MCA bypass surgery. HMPAO-SPECT repeated 4±1 months after surgery showed significant improvement in all cases. Significantly better improvement (14.5%) in cerebral perfusion was noted in the cortical regions as compared to the subcortical regions (4.5%, p&lt;0.005). Conclusion: STA-MCA bypass surgery in carefully selected patients with symptomatic severe intracranial steno-occlusive disease results in significant improvement in cerebral perfusion, especially in the cortical regions.

Abstract WMP112: Internal Carotid Artery Stenosis and Flow Diversion: Relationship With Headache

Background: The phenomenon of flow diversion in high grade internal carotid artery (ICA) stenosis and secondary head and facial pain from increased regional flow in the external carotid artery (ECA) system remains under-recognized and unreported. We examine this phenomenon in a large study population of Asymptomatic Carotid Atherosclerosis Study Methods: We utilized the Asymptomatic Carotid Atherosclerosis Study (ACAS) data to explore the relationship between ICA stenosis and headache. In ACAS, eligible patients with carotid stenosis ≥ 60 % were randomized to endarterectomy or medical management and risk of stroke or stroke &amp; death over 5 years was observed. Information on headache and its characteristics was collected at the baseline visit and comprised questions inquiring self-reported history of headache, including characteristics of migraine, and physician diagnosis of headache. Carotid stenosis was evaluated by doppler ultrasound (as &lt;60%, 60-80%, 81-99%, and 100%) and catheter angiography (as percent stenosis). All analyses were performed using IBM SPSS (version 20) software. Results: In this study (n= 1662), patients with stenosis (measured by Doppler) of 60% or higher in the right ICA or left ICA, self-reported headache within the past year was reported in 424, and physician diagnosed headache in only 68 patients. Significant relationship was noted between physician diagnosis of headache and right ICA (χ2=10.3, df=4, p 0.036), and left ICA (χ2=15.6, df=4, p=0.004) stenosis categories. Self-reported history was associated with left ICA stenosis (χ2=26.6, df=4, p&lt;0.001). Average stenosis measured by angiogram was 57% in the right ICA and 56% in the left ICA in this study population. No relationship with self-reported or physician diagnosed headache was noted with percent stenosis measured by catheter angiogram. Conclusion: Recognition of flow-diversion into the ECA as a possible mechanism for headaches may help in further understanding of ICA disease, its progression, and the effects of carotid revascularization on quality of life. Headache as a likely surrogate marker of carotid stenosis with flow-diversion warrants more research, and may be critical in the early identification of significant ICA stenosis and prevention of TIA or stroke.

Abstract 13250: Gender Differences in Asymptomatic Carotid Artery Stenosis; the Association of Age and Smoking With Disease Progression in Males

Background: A direct relationship exists between internal carotid artery (ICA) disease progression and stroke incidence. For asymptomatic patients with known ICA disease, there is no proven surveillance strategy. It remains unclear which individuals are at greater risk for disease progression, and whether there are gender-specific risk factors. We examined clinical characteristics associated with ICA disease progression in men and women undergoing carotid duplex ultrasound (CDU) surveillance. Methods: We retrospectively studied 289 patients with known ICA stenosis at baseline who underwent CDU from 2008-2014 and had at least one other CDU ≥11 months later. Categories of stenosis included minimal (0-15%), mild (16-49%), moderate (50-79%), and severe (80-99%). Symptomatic patients (stroke or TIA within 6 months), those with severe baseline stenosis, and arteries with prior interventions were excluded. The primary outcome was progression of stenosis to a level of moderate or higher. Baseline clinical data was recorded, and logistic regression analysis was performed. Results: Twenty-seven (23%) of 116 females and 30 (17%) of 173 males had progression of ICA stenosis (p=0.21). Females with disease progression were more likely to have moderate baseline stenosis (52% vs 26%, p = 0.01) compared to mild or minimal. Males with disease progression were older (74y vs 70y, p &lt; 0.04), more likely to be current or past smokers (66% vs 44%, p = 0.03), and more likely to have moderate baseline stenosis (50% vs 23 %, p&lt;0.003). Multivariate analysis in males showed age, smoking, and moderate baseline stenosis to be independent predictors of disease progression. Conclusion: There was no significant difference in proportion of disease progression between genders. In addition to relying on baseline stenosis for both genders, our findings suggest a role for age and smoking history to help determine effective surveillance protocols for monitoring ICA disease progression in males.

Increase in [18F]-Fluoroacetate Uptake in Patients With Chronic Hemodynamic Cerebral Ischemia.

[18F]-fluoroacetate ((18)F-FACE) can be used for evaluating glial cell metabolism. Experimental studies have shown an increase in (18)F-FACE uptake in rodent models of cerebral ischemia. The aim of this study was to determine whether (18)F-FACE uptake is increased in the noninfarcted cerebral cortex in patients with hemodynamic ischemia owing to atherosclerotic internal carotid artery or middle cerebral artery disease. We evaluated 9 symptomatic patients with unilateral atherosclerotic internal carotid artery or middle cerebral artery disease and no cortical infarction using positron emission tomography with (18)F-FACE and (15)O-gases. (18)F-FACE uptake during 40 to 60 minutes after injection was compared with the cerebral blood flow, cerebral metabolic rate of oxygen, oxygen extraction fraction, and cerebral blood volume in the middle cerebral artery distributions. Significant decreases of cerebral blood flow and cerebral metabolic rate of oxygen and increases of oxygen extraction fraction and cerebral blood volume were found in the hemisphere ipsilateral to the arterial lesion, and (18)F-FACE uptake in this region was greater than that in the contralateral hemisphere. The relative (18)F-FACE uptake (ipsilateral/contralateral ratio) was negatively correlated with cerebral blood flow or cerebral metabolic rate of oxygen values and was positively correlated with oxygen extraction fraction values. Multivariate analysis showed that the ipsilateral/contralateral (18)F-FACE uptake ratio was independently correlated with the cerebral blood flow (or oxygen extraction fraction) and cerebral metabolic rate of oxygen values. In patients with atherosclerotic internal carotid artery or middle cerebral artery disease, (18)F-FACE uptake is increased in the noninfarcted cerebral cortex with chronic hemodynamic ischemia characterized by misery perfusion with decreased oxygen metabolism. Increased (18)F-FACE uptake may indicate the cortical regions that are at particular risk for ischemic damage.

Vascular tortuosity may be related to intracranial artery atherosclerosis.

Conventional risk factors cannot explain the individual or ethnic difference in the location of cerebral atherosclerosis. Vascular geometry may play a role on this. To investigate the association between the geometrical properties of the middle cerebral artery and intracranial atherosclerosis. Stroke patients with either symptomatic middle cerebral artery or proximal internal carotid artery diseases were enrolled. The diameter, length, and tortuosity (arc-chord ratio, by percent) of the middle cerebral artery was compared between stroke patients and the age- and gender-matched healthy subjects. The geometrical property was also compared between the symptomatic middle cerebral artery and the normal-looking contralateral middle cerebral artery, and between the contralateral middle cerebral arteries in patients with symptomatic middle cerebral artery and proximal internal carotid artery diseases. One hundred seventy-seven patients (101 with middle cerebral artery disease and 76 with proximal internal carotid artery disease) were studied. Symptomatic middle cerebral artery was more tortuous (119·31 ± 16·95 vs. 112·98 ± 14·16; P = 0·009) than the contralateral middle cerebral artery. The contralateral middle cerebral artery of patients with symptomatic middle cerebral artery disease demonstrated a smaller proximal diameter (P = 0·007) and a greater vascular tortuosity than the contralateral middle cerebral artery of patients with proximal internal carotid artery disease (112·01 ± 12·25 vs. 107·46 ± 9·35; P = 0·008) and corresponding middle cerebral artery of healthy control subjects (112·01 ± 12·25 vs. 108·73 ± 9·79; P = 0·04). Young age, female, small diameter, the absence of diabetes, and high tortuosity of the contralateral middle cerebral artery were independently associated with middle cerebral artery atherosclerotic disease. High tortuosity and small diameter are related to middle cerebral artery atherosclerosis, probably by altering hemodynamics. Different degree of tortuosity may be one of the reasons for individual differences in location of cerebral atherosclerosis.

Common carotid intima–media features determine distal disease phenotype and vulnerability in asymptomatic patients

ObjectivesThere is a growing awareness of the importance of carotid plaque features evaluation in stroke prediction. Carotid intima–media thickness (IMT) and recently its echogenicity were used for stroke prediction, although their clinical relevance was not well determined. The aim of this study was to assess the relationship between common carotid artery (CCA) ultrasound markers of atherosclerosis and distal, bifurcation and internal carotid artery (ICA), plaque features. MethodsWe analyzed 137 carotid arteries in 87 asymptomatic patients with known carotid disease (mean age 69±6year, 34.5% females). Intima media thickness (IMT) and its gray scale median (IM-GSM) were measured at the CCA. Plaque textural features including gray scale median (GSM), juxtaluminal black area (JBA-mm2) without a visible cap, and plaque coarseness, at bifurcation and ICA were also determined. CCA measurements were correlated with those of the distal plaques. ResultsAn increased IMT in CCA correlated with plaque irregularities in the bifurcation and ICA (r=0.53, p<0.001), while IM-GSM was closely related to plaque echogenicity (GSM) (r=0.76, p<0.001), and other textural plaque features. Both, IMT and IM-GSM correlated weakly with stenosis severity (r=0.27, p=0.001 and r=−0.18, p=0.026) respectively. ConclusionIn asymptomatic patients, measurements of CCA reflect distal, bifurcation and ICA disease, with IMT reflecting plaque irregularities and IM-GSM as markers of textural plaque abnormalities. Integrating measurements of both IMT and IM-GSM in a model could be used as a better marker of disease vulnerability over and above each measure individually.

Improvement in cerebral hemodynamic parameters and outcomes after superficial temporal artery-middle cerebral artery bypass in patients with severe stenoocclusive disease of the intracranial internal carotid or middle cerebral arteries.

Both the older and the recent extracranial-intracranial (EC-IC) bypass trials for symptomatic carotid occlusion failed to demonstrate a reduction in stroke recurrence. However, the role of superficial temporal artery (STA)-middle cerebral artery (MCA) bypass in patients with symptomatic intracranial stenoocclusive disease has been rarely evaluated. The authors evaluated serial changes in various cerebral hemodynamic parameters in patients with severe stenoocclusive disease of the intracranial internal carotid artery (ICA) or middle cerebral artery (MCA) and impaired cerebral vasodilatory reserve (CVR), treated by STA-MCA bypass surgery or medical treatment. Patients with severe stenoocclusive disease of the intracranial ICA or MCA underwent transcranial Doppler (TCD) ultrasonography and CVR assessment using the breath-holding index (BHI). Patients with impaired BHI (< 0.69) were further evaluated with acetazolamide-challenge technitium-99m hexamethylpropyleneamine oxime ((99m)Tc HMPAO) SPECT. STA-MCA bypass surgery was offered to patients with impaired CVR on SPECT. All patients underwent TCD and SPECT at 4 ± 1 months and were followed up for cerebral ischemic events. A total of 112 patients were included. This total included 73 men, and the mean age of the entire study population was 56 years (range 23-78 years). (99m)Tc HMPAO SPECT demonstrated impaired CVR in 77 patients (69%). Of these 77 patients, 46 underwent STA-MCA bypass while 31 received best medical treatment. TCD and acetazolamide-challenge (99m)Tc HMPAO SPECT repeated at 4 ± 1 months showed significant improvement in the STA-MCA bypass group. During a mean follow-up of 34 months (range 18-39 months), only 6 (13%) of 46 patients in the bypass group developed cerebral ischemic events, as compared with 14 (45%) of 31 patients receiving medical therapy (absolute risk reduction 32%, p = 0.008). STA-MCA bypass surgery in carefully selected patients with symptomatic severe intracranial stenoocclusive disease of the intracranial ICA or MCA results in significant improvement in hemodynamic parameters and reduction in stroke recurrence.

Assessing internal carotid artery stenosis with a semiautomated computed tomography angiography tool and duplex ultrasound

Duplex ultrasound (DUS) and computed tomography angiography (CTA) are both used as first-line noninvasive methods to investigate patients for internal carotid artery (ICA) disease. Although manual assessment of CTA is well established, semiautomated vessel analysis programs have yet to prove their clinical benefit. We compared one such vessel analysis program (TeraRecon, Foster City, Calif) with DUS. A total of 85 arteries in 50 patients (35 men, 15 women; mean age, 73 ± 10 years) were eligible for comparison with the North American Symptomatic Carotid Endarterectomy Trial method. Duplex scanning comprised stenosis estimation based on (1) the intrastenotic and distal ICA diameter measurements on color-coded imaging (CCI), (2) the application of German Society for Ultrasound in Medicine (DEGUM) criteria (intrastenotic peak systolic velocity [PSV] ≥ 2 00 cm/s indicates 50% stenosis; intrastenotic PSV ≥ 300 cm/s together with a PSV of ≥ 50 cm/s in the distal ICA indicates 70% stenosis), and (3) the application of the University of Washington stenosis criteria (≥ 50% stenosis is indicated by PSV >125 cm/s and end-diastolic velocity <140 cm/s; ≥ 80% stenosis is indicated by PSV >125 cm/s and end-diastolic velocity ≥ 140 cm/s). The minimum and maximum diameters at the stenosis site and at the distal reference ICA were automatically measured with the CTA vessel analysis tool. In addition, automated tracking generated corresponding cross-sectional areas at these two sites. Angiographic stenosis was then calculated using the minimum diameter (CTAmin), the average of the minimum and maximum diameters (CTAavg), and the areas (CTAarea) at both sites. Compared with duplex CCI, the three CTA modalities exhibited only a moderate agreement in terms of regression analysis (R(2) = 0.41-0.54) and Bland-Altman analysis (the standard deviation of the stenosis differences was >20%). In terms of sensitivity, specificity, positive predictive value, negative predictive value, and accuracy, DEGUM stenosis graduation was best balanced by duplex CCI (50% stenosis: 100%, 93%, 85%, 100%, 95%; 70% stenosis: 71%, 100%, 100%, 97%, 98%) followed by CTAarea (50% stenosis: 80%, 73%, 54%, 90%, 75%; 70% stenosis: 66%, 94%, 55%, 96%, 96%). University of Washington stenosis was best balanced by duplex CCI followed by CTAarea. CTA analysis with a semiautomated vessel analysis tool provides variable results. Large discrepancies between methods in the degree of reported stenosis must be taken into consideration when CTA and DUS are used for clinical purposes. The semiautomated software tools need further improvements.

Abstract T P181: Static And Dynamic Cerebral Autoregulation Dissociate In Asymptomatic Carotid Artery Disease

Background: High grade internal carotid artery (ICA) disease can alter cerebral autoregulation and thus increase risk for ischemia. We aimed to differentiate two types of autoregulation - dynamic cerebral autoregulation (DCA), thought to be a homeostatic process, and vasomotor reactivity (VMR), which determines cerebrovascular reserve - in patients with asymptomatic ICA stenosis. Methods: Twenty-two patients (age 50-93, 16M) with unilateral 80-100% ICA occlusion but no stroke underwent quantitative CBF measurements using continuous arterial spin labeling (CASL) MRI. DCA was performed by continuous insonation of both middle cerebral arteries with transcranial Doppler for 10 minutes at depth 56mm using a standard head frame. Phase shift (PS) between spontaneous oscillations in blood pressure (measured with finger photoplethysmography (Finapres)) and MCA mean flow velocities (MFV) at frequencies .06-.12 Hz was calculated for each hemisphere using transfer function analysis. Lower degree of PS indicated worse autoregulation (abnormal &lt;24deg1). VMR was determined as a response to 2 minutes of 5% CO2 inhalation (abnormal &lt;2% rise in MCA MFV per mmHg PCO2 by Doppler-integrated inline capnometer (Spencer Technologies)). T-test Chi-square, and multivariable linear regression were used to look for associations between VMR, DCA, and hemispheral CBF (SPSS v.22). Results: MCA MFV (p&lt;.001), VMR (p=.002), and CBF (p&lt;.003), were lower in the ICA occlusion hemisphere. DCA difference approached significance (p=0.064). Controlling for age and anterior circle of Willis collateral cross-filling, DCA (p=0.024), but not VMR (p=0.079) on the occluded side was associated with greater hemispheral CBF asymmetry (F=6.87, p=0.024). VMR and DCA were not correlated (Fisher exact =.61). Conclusions: DCA but not VMR correlated with a low flow state produced by high grade ICA disease in asymptomatic patients. Our results suggest that in ICA stenosis dynamic/homeostatic mechanisms may be affected without substantially altering the static/protective mechanism of cerebrovascular reserve. Ongoing studies will investigate the effect of these two autoregulatory mechanisms on vascular cognitive impairment. 1 Ortega-Gutierrez S, et al. J Neuroimaging. 2014 24:379-86

Abstract 74: Improvement in Cerebral Hemodynamic Parameters and Outcome after Superficial Temporal Artery- Middle Cerebral Artery Bypass in Patients with Severe Steno-occlusive Disease of Intracranial Carotid and Middle Cerebral Artery

Background and Objective: Older and the recent extracranial-intracranial (EC/IC) bypass trials for symptomatic carotid occlusion failed to demonstrate reduction in stroke recurrence. However, role of superficial temporal artery-middle cerebral artery (STA-MCA) bypass in patients with symptomatic intracranial steno-occlusive disease has been evaluated scarcely. We evaluated serial changes in various cerebral hemodynamic parameters in patients with severe steno-occlusive disease of intracranial internal carotid (ICA) or middle cerebral artery (MCA) and impaired cerebral vasodilatory reserve (CVR), treated with STA-MCA bypass surgery or medical treatment. Methods: Patients with severe steno-occlusive disease of intracranial ICA or MCA underwent transcranial Doppler (TCD) ultrasonography and CVR assessment using breath-holding index (BHI). Patients with impaired BHI (&lt;0.69) were further evaluated with acetazolamide-challenged hexamethylpropyleneamine-oxime single-photon emission computed tomography (HMPAO-SPECT). STA-MCA bypass surgery was offered to patients with impaired CVR on SPECT. All patients underwent TCD and SPECT at 4±1 months and followed-up for cerebral ischemic events. Results: A total of 112patients (73males, mean age 56yrs; range 23-78yrs) were included. HMPAO-SPECT demonstrated impaired CVR in 77 (69%) patients. Of them, 46 underwent STA-MCA bypass while 31 received best medical treatment. TCD and acetazolamide-challenged HMPAO-SPECT repeated 4±1months showed significant improvement in STA-MCA bypass group. During follow-up (mean 34months; range 18-39months), only 6/46 (13%) patients in bypass group developed cerebral ischemic events as compared to 14/31 (45%) cases on medical therapy (absolute risk-reduction 32%, p=0.008). Conclusion: STA-MCA bypass surgery in carefully selected patients with symptomatic severe intracranial steno-occlusive disease results in significant improvement in hemodynamic parameters and reduction in stroke recurrence.

Evidence for Cerebral Hemodynamic Measurement-based Therapy in Symptomatic Major Cerebral Artery Disease.

In patients with atherosclerotic internal carotid artery or middle cerebral artery occlusive disease, chronic reduction in cerebral perfusion pressure (chronic hemodynamic compromise) increases the risk of ischemic stroke and can be detected by directly measuring hemodynamic parameters. However, strategies for selecting treatments based on hemodynamic measurements have not been clearly established. Bypass surgery has been proven to improve hemodynamic compromise. However, the benefit of bypass surgery for reducing the stroke risk in patients with hemodynamic compromise is controversial. The results of the two randomized controlled trials were inconsistent. Hypertension is a major risk factor for stroke, and antihypertensive therapy provides general benefit to patients with symptomatic atherosclerotic major cerebral artery disease. However, the benefit of strict control of blood pressure for reducing the stroke risk in patients with hemodynamic compromise is a matter of debate. The results of the two observational studies were different. We must establish strategies for selecting treatments based on hemodynamic measurements in atherosclerotic major cerebral artery disease.

Can Internal Carotid Artery Occlusion Produce Simultaneous Anterior and Posterior Circulation Stroke?

Collateral circulation in the brain is important for maintaining a sufficient cerebral blood flow in case of obstructive disease of arteries. In case of hemodynamic compromise to the anterior circulation, the posterior circulation supplies the anterior circulation via the collaterals. Simultaneous anterior and posterior circulation stroke is a very rare occurrence. It can occur due to cardioembolic stroke or due to anatomical variants of the circle of Willis. Fetal origin of the posterior cerebral artery (PCA) from the internal carotid artery (ICA), persistent trigeminal artery, and persistent hypoglossal artery are known to present with posterior circulation stroke due to occlusive disease of ICA. Here we report a 85-year-old man who presented to us with left hemiparesis. On evaluation, he had right middle cerebral artery (MCA), anterior cerebral artery (ACA), and PCA infarct. Our case most likely had fetal PCA, which can readily explain the PCA infarction in ICA occlusion. Although cases of simultaneous MCA and PCA infarction had been reported in past, we report the first case with simultaneous ACA, MCA, and PCA infarction secondary to fetal PCA.

External Carotid Artery Stenosis after Internal and Common Carotid Stenting

The external carotid artery (ECA) can be an important collateral for cerebral perfusion in the presence of severe internal carotid artery (ICA) disease. ICA stenting that covers the ECA origin may put the ECA at increased risk of stenosis. Our objective was to determine the rate of ECA stenosis secondary to ICA stenting, determine predictive factors, and describe any subsequent associated symptoms. We retrospectively reviewed clinical data on all ICA stents crossing the origin of the ECA placed by vascular surgeons at our institution. We analyzed patient demographics, comorbidities, stent type and sizes, as well as medication profile to determine predictors of ECA stenosis. Between 2005 and 2013, there were 72 (out of 119 total ICA stenting) patients (mean age 71, 68% male) who underwent placement of ICA stents that also crossed the origin of the ECA. Six patients (8.3%) had a significantly increased ECA stenosis postprocedure. There were no occlusions. All patients with ECA stenosis maintained patency of their ICA stent and were asymptomatic. Age, gender, comorbidities, stent type and size, and medication profile were not associated with ECA stenosis after stenting. ECA stenosis after ICA stenting covering the ECA origin is uncommon and not clinically significant in patients with patent ICA stents. The clinical significance of concurrent ECA and ICA stenosis after stenting is unclear as it is not captured here. The potential for ECA stenosis should not deter stenting across the ECA origin if necessary. Patient and stent factors are not predictive of ECA stenosis.

Pasado, presente y futuro de la angioplastia y stent carotídeo

With more than 45,000 patients treated worldwide and 33 prospective registries, 8 multicenter randomized trials, and a 15-year history of carotid artery stenting (CAS), there are still many unresolved issues. Carotid endarterectomy (CEA) is a preventive treatment with established preventive efficacy in patients with atherosclerotic disease of the extracranial internal carotid artery. But not all patients are perfect candidates. When analyzing the most recent data, CEA seems to be the «clear winner», but CAS is undoubtedly a very welcome addition to our armamentarium.

Paradoxical reduction of cerebral blood flow after acetazolamide loading: a hemodynamic and metabolic study with (15)O PET.

Paradoxical reduction of cerebral blood flow (CBF) after administration of the vasodilator acetazolamide is the most severe stage of cerebrovascular reactivity failure and is often associated with an increased oxygen extraction fraction (OEF). In this study, we aimed to reveal the mechanism underlying this phenomenon by focusing on the ratio of CBF to cerebral blood volume (CBV) as a marker of regional cerebral perfusion pressure (CPP). In 37 patients with unilateral internal carotid or middle cerebral arterial (MCA) steno-occlusive disease and 8 normal controls, the baseline CBF (CBF(b)), CBV, OEF, cerebral oxygen metabolic rate (CMRO2), and CBF after acetazolamide loading in the anterior and posterior MCA territories were measured by (15)O positron emission tomography. Paradoxical CBF reduction was found in 28 of 74 regions (18 of 37 patients) in the ipsilateral hemisphere. High CBF(b) (> 47.6 mL/100 mL/min, n = 7) was associated with normal CBF(b)/CBV, increased CBV, decreased OEF, and normal CMRO2. Low CBF(b) (< 31.8 mL/100 mL/min, n = 9) was associated with decreased CBF(b)/CBV, increased CBV, increased OEF, and decreased CMRO2. These findings demonstrated that paradoxical CBF reduction is not always associated with reduction of CPP, but partly includes high-CBF(b) regions with normal CPP, which has not been described in previous studies.

A cohort study of duplex Doppler examinations of the carotid artery in primary open angle glaucoma.

ObjectivesTo explore the possibility of pathological change in the common carotid artery at the bifurcation and in the internal carotid artery beyond the bifurcation which could contribute to a reduced diastolic pressure as observed in primary open angle glaucoma.DesignDuplex ultrasonic examinations of carotid bifurcations were conducted on 80 patients. Carotid artery defects were allocated into three types: no demonstrable flow defects, internal carotid artery abnormalities and disease in the carotid bulb.SettingBristol Royal Infirmary Vascular Laboratory.ParticipantsEighty patients (mean age 69.6 years) providing a total of 160 sides to the analysis.Main outcome measuresAn estimated central retinal artery pressure, intraocular pressure and field loss were recorded for each side measured.ResultsDoppler investigations revealed significant levels of pathological change in the internal carotid distinct from changes at the carotid bulb. The disease revealed in the internal carotid artery was significantly associated with intraocular pressure (p = 0.032), with an effect small to medium in magnitude. The Q2 measure, derived from mean arterial pressure and intraocular pressure, was also substantively associated with disease in the internal carotid artery. Both intraocular pressure and the Q2 measure effectively discriminated between groups, with field loss providing rather less discriminating capability. There was a strong trend towards a higher intraocular pressures and a greater visual field loss with internal carotid artery disease.ConclusionsPathological changes in the extra cranial carotid artery in primary open angle glaucoma exceed those in the arteries classified as normal. The presence of disease specifically in the internal carotid artery emphasised the need for a mechanism for the evaluation of the internal carotid apart from the carotid bulb. A basis for clarifying the presence of an ischaemic zone is proposed.

Left ventricular systolic dysfunction inoutpatients with peripheral atherosclerotic vascular disease: prevalence and association with location of arterial disease.

We aimed to determine the prevalence of left ventricular systolic dysfunction (LVSD) in outpatients with peripheral atherosclerotic vascular disease (PAVD). Further, the associations of stenotic internal carotid artery disease (SICAD) and lower extremity artery disease (LEAD) with LVSD were evaluated. In the Peripheral Artery Disease in Västmanland study, consecutive outpatients with ultrasonographically identified mild to severe stenosis in the internal carotid artery or symptoms of claudication combined with either ankle brachial index of ≤0.90 or ultrasonographic occlusive findings were included (n = 437). Population-based control subjects were matched to the patients (n = 395). LVSD was defined as echocardiographically determined left ventricular ejection fraction (LVEF) <55%, and moderate or greater LVSD was defined as LVEF <45%. The prevalence of LVSD was significantly greater in patients than in controls (13.7% vs. 6.1%, P < 0.001). The prevalence of moderate or greater LVSD in participants not on treatment with a combination of angiotensin-converting enzyme inhibitor and beta-blocker was 2.3% in patients and 1.3% in controls (P = 0.31). When LEAD and SICAD were analysed together, adjusted for potential confounders, SICAD [odds ratio (OR) 2.54, 95% confidence interval (CI) 1.03-6.32], but not LEAD (OR 1.59, 95% CI 0.80-3.18), was independently associated with LVSD. In outpatients with PAVD, we found a 13.7% prevalence of LVSD. However, the prevalence of at least moderate LVSD in patients not on treatment with angiotensin-converting enzyme inhibitor and a beta-blocker was only 2.3% and not significantly different from controls. Stenotic artery disease in the internal carotid artery, but not in the lower extremities, was independently associated with LVSD.

Thyroid antibodies are associated with stenotic lesions in the terminal portion of the internal carotid artery

Several studies have reported moyamoya syndrome associated with thyroid disease, and the mechanism involved in this relationship is unknown. This study aimed to clarify the involvement of thyroid antibodies and thyroid function in intracranial arterial stenosis. The study included 30 patients <65years of age with intracranial arterial steno-occlusion. Patients with definitive moyamoya disease were excluded. Thyroid function and thyroid antibody levels were evaluated. The steno-occlusive site and the presence of moyamoya vessels were evaluated using digital subtraction angiography. The characteristics of intracranial arterial lesions were compared between patients with and without elevated thyroid antibody levels, and between patients with increased thyroid function and those with normal thyroid function. Five patients had increased thyroid function and seven had elevated thyroid antibody levels. Four were diagnosed with Graves' disease, 13 with atherosclerotic intracranial stenosis, two with intracranial arterial dissection, one with vasculitis syndrome and 10 with intracranial stenosis of unknown cause. All patients with Graves' disease and patients with elevated antithyroid peroxidase antibody levels had steno-occlusion in the terminal portion of the internal carotid arteries, whereas most of the patients with normal thyroid function or without elevated thyroid antibody levels had stenosis in the middle cerebral arteries. In young and middle-aged patients, a lesion in the terminal portion of the internal carotid artery was associated with elevated thyroid antibody levels and increased thyroid function. Stenoses found in the terminal portion of the internal carotid artery and immune-mediated thyroid diseases may share a common background.