External Carotid Artery Stenosis Research Articles

Cerebral hemodynamics and cognitive functions in the acute and subacute stage of mild ischemic stroke: a longitudinal pilot study.

The association between cerebral hemodynamics and cognitive impairment has been reported in neurodegenerative and cerebrovascular disorders (CVD). However, it is still unclear whether changes occur in the acute phase of CVD. Here we investigated cognitive and hemodynamic parameters and their association in patients with CVD during the acute and subacute phases. Seventy-three patients with mild stroke, not undergoing endovascular treatment, were recruited. All subjects were devoid of intracranial or external carotid stenosis, significant chronic cerebrovascular pathology, dementia or non-compensated cardiovascular diseases. Patients were evaluated within 7days from symptoms onset (T1) and after 3months (T2). Clinical and demographic data were collected. NIHSS, MoCA, FAB, and Word-Color Stroop test (WCST) were used to evaluate disease severity and cognitive functions. Basal hemodynamic parameters in the middle cerebral artery were measured with transcranial Doppler. Differences between T2 and T1, correlations between cognitive and hemodynamic variables at T1 and T2, as well as correlations between the T2-T1 variation in cognitive and hemodynamic parameters were assessed. At T1, cognitive performance of MoCA, FAB, and WCST was lower compared with T2; and pulsatility index, a parameter reflecting distal vascular resistance, was higher. However, no correlations between the changes in cognitive and hemodynamic variables were found; therefore, the two seems to be independent phenomena. In the acute phase, the linear association between cerebral blood flow and cognitive performances was lost, probably due to a differential effect of microenvironment changes and vascular-specific phenomena on cognition and cerebral hemodynamics. This relationship was partially restored in the subacute phase.

Abstract 097: Un‐stumped by Carotid Stump Syndrome: Use of External Carotid Stenting in Preventing Ischemic Stroke

Introduction Recurrent infarcts to the internal carotid artery territory in the setting of a corresponding occlusion raises concern for carotid stump syndrome. Over time, robust anastomoses may develop between the patent ipsilateral external carotid artery and the anterior circulation distal to the site of occlusion. A carotid stump’s disturbance of flow uncommonly can form emboli that travel via retrograde flow from the occluded internal carotid artery to the ipsilateral external carotid artery and its collaterals. Stenosis of the external carotid artery in such patients can be a source of atheroembolism or hypoperfusion. We describe a case of external carotid stenting with carotid stump coil occlusion. Methods We present a case report. Verbal consent to share this information was obtained directly from the patient. Results A 75‐year‐old man with aortic stenosis, atrial arrhythmia, multiple prior bi‐hemispheric strokes, on aspirin and clopidogrel, presented with left facial droop, arm weakness, and slurred speech. Magnetic resonance imaging revealed embolic appearing strokes in the right middle cerebral artery territory (Figure 1A). Cerebral angiography revealed complete occlusion of the right internal carotid artery with perfusion of the right middle cerebral artery by external carotid artery anastomoses, and the external carotid was found to be stenosed proximally. Digital subtraction angiography revealed right external carotid – middle cerebral artery anastomoses via the right sphenopalatine artery, middle meningeal artery, internal maxillary artery, and ophthalmic collaterals (Figure 1B). The patient underwent coiling of the right internal carotid artery stump (Figure 1C) followed by stenting of the right external carotid using a 9 mm x 40 mm Cordis precise Pro stent. Post‐stenting angiogram demonstrated good apposition of the stent to the parent vessel walls and improvement of flow into the right external carotid and intracranial circulation (Figure 1D). The patient was treated with aspirin and ticagrelor for 3 months. Repeat imaging at follow up did not show further embolic episodes, with improvement in the patient’s deficits. After three months, he was continued on aspirin alone. Conclusion In patients with an occluded internal carotid artery and recurrent embolic infarcts ipsilateral to the side of the occlusion, carotid stump syndrome may be considered. In this case, we believe the patient’s carotid occlusion served as a nidus for emboli formation, or that there was atheroembolism from the stenosed external carotid artery despite adherence to dual antiplatelet therapy. By coiling the stump, we addressed a possible source of emboli, and stenting of the proximal external carotid optimized anterograde flow and prevented further atheroembolism. Our case showcases an interventional neuroradiology approach to carotid stump emboli and external carotid artery stenosis.

THE BENEFITS OF DUPLEX SCANNING OF EXTRACRANIAL CAROTID PATHOLOGIES FOR RISK STRATIFICATION OF ISCHEMIC STROKE

Abstract Introduction: Recent retrospective cohort study demonstrated the benefit of duplex scanning in the examination of the extracranial carotid artery pathologies for preventing cerebrovascular disorders. The aim of this study: was to evaluate the clinical and demographical characteristics and outcome in patients treated at National Scientific Center of Surgery, after detecting extracranial carotid artery stenosis ≥70%. Material and methods: A retrospective cohort study was conducted; 204 patients were included. Results: The most significant risk factors were: ischemic heart diseases – 95.6%, arterial hypertension – 80.1%, chronic heart failure – 83.8%, cholesterol level above the norm of 5.2 mmol/L-39.2%; 30.4% of patients had a history of postinfarction cardiosclerosis. There were a significant statistically difference between the prevalence of extracranial carotid artery stenosis depending on the risk factors (blood cholesterol levels, a clinical history of chronic heart failure, and acute cerebrovascular diseases p=0.048, p=0.003, p=0.048 respectively (p>0.05)). Conclusion: In summary, we conclude that surgery should be considered, and duplex ultrasound plays a crucial role in assessing the severity of carotid stenosis in atherothrombotic stroke patients with severe external carotid stenosis. These data indicate that physicians, should be aware of the usefulness of carotid duplex ultrasound scanning in stratifying the risk of cerebral and cardiovascular diseases based on various aspects.

Is External Carotid Artery Hemodynamics Helpful in Detecting Internal Carotid Artery Stenosis?

Introduction: There is a paucity of validated external carotid artery (ECA) velocity criteria and data on the association between ECA velocities and internal carotid artery (ICA) stenosis by carotid duplex ultrasound (CDU) scanning. Our objectives were to determine the relationships between ECA peak systolic velocity (PSV) and percent stenosis seen on confirmatory imaging, as well as to correlate ECA hemodynamics with known ICA disease by CDU. Methods: A retrospective chart review was performed for patients who had CDU, as well as confirmatory testing such as angiography, at a single academic medical center. ICA stenosis was grouped into 4 categories (0 = <50%, 1 = 50%-69%, 2 = 70%-99%, 3 = 100%) based on validated CDU criteria. ECA PSVs were analyzed, in addition to degree of both ECA and ICA stenosis from the same CDU study. Results: Of 247 carotid arteries reviewed, 136 vessels were included in the final analysis. The mean PSV of the normal ECA cohort (<50% ECA stenosis per the NASCET measurement method) was 135.3 ± 82.1 cm/s, and the mean PSV of the diseased ECA cohort was 279.7 ± 112.2 cm/s. Mean ECA PSV for each category of ICA stenosis was: ICA category 0 = 119.9 cm/s; category 1 = 200.4 cm/s; category 2 = 167.7 cm/s; and category 3 = 155.5 cm/s. There was a statistically significant but non-linear difference in ECA velocities between ICA stenosis categories 0 vs 1 (mean rank diff. −49.91 cm/s; P = .0007); and 0 vs 2 (mean rank diff. −32.61 cm/s; P = .0047). Conclusion: We have demonstrated a possible separation of <50% vs ≥50% stenosis of the ICA using ECA PSV. Although the data suggest a weak but statistically significant correlation between ECA PSV and degree of ICA stenosis, further data with a larger sample size and confirmatory studies are needed to utilize ECA hemodynamics to indicate ICA disease.

Impact of radiotherapy for nasopharyngeal carcinoma on carotid stenosis risk: a meta-analysis

ObjectsRadiotherapy (RT) serves as the most effective treatment for Nasopharyngeal Carcinoma (NPC) and can cause carotid stenosis. The aim of this study is to assess the impact of RT on carotid stenosis in NPC patients, as well as to explore the risk factors for significant carotid stenosis. MethodsStudies reporting the carotid stenosis in NPC patients who underwent RT were found on PubMed, Embase and Web of Science. Outcomes of our interest included incidence of overall/significant stenosis, Common Carotid Artery (CCA) stenosis, External Carotid Artery (ECA) stenosis, Internal Carotid Artery (ICA) stenosis, and risk factors for significant carotid stenosis. ResultsSixteen studies met the inclusion criteria and were included in this meta-analysis. Pooled estimate showed that RT was associated with a significantly higher incidence of overall stenosis (Risk Ratio [RR = 3.53], 95% CI: 2.32‒5.37; p < 0.001) and significant stenosis (RR = 7.06, 95% CI: 3.61‒13.79; p < 0.001) as compared with controls. Moreover, patients treated with RT had a significantly higher risk of stenosis in CCA (RR = 6.87, 95% CI: 4.08‒11.58; p < 0.001), ICA (RR = 3.43, 95% CI: 1.35‒8.73; p = 0.010), ECA (RR = 9.37, 95% CI: 2.06‒42.68; p = 0.004), and ECA/ICA (RR = 2.18, 95% CI: 1.52‒3.13; p < 0.001). Meta-analysis indicated that age (RR = 1.46, 95% CI: 1.05‒2.04; p = 0.024), smoking habit (RR = 1.20, 95% CI: 1.02‒2.78; p = 0.045) and time interval from radiotherapy (RR = 1.56, 95% CI: 1.07‒2.28; p = 0.02) were independent predictors of significant carotid stenosis. ConclusionOur results suggested that RT increased the risk of carotid stenosis in patients with NPC. Prevention and control measurements should be made for older NPC patients with longer interval from RT, especially those with smoking habit. Level of evidence3.

The AIUM Practice Parameter for the Performance of an Ultrasound Examination of the Extracranial Cerebrovascular System.

The AIUM Practice Parameter for the Performance of an Ultrasound Examination of the Extracranial Cerebrovascular System.

External carotid artery to internal carotid artery transposition to augment flow for a superficial temporal artery to middle cerebral artery bypass associated with severe external carotid artery stenosis.

Donor vessel quality can impact the outcome of extracranial-intracranial (EC-IC) bypass. External carotid artery (ECA) disease may produce embolism into the anastomosis and cerebral territory and possibly reduce flow in the superficial temporal artery (STA). Previously reported remedies to ECA stenosis include ECA endarterectomy, stenting, and angioplasty. Clinical presentation A middle-aged patient with chronic left MCA occlusion, progressive ischemic symptoms on maximal medical therapy, and imaging confirmation of compromised hemodynamic reserve was evaluated for EC-IC bypass. Angiography demonstrated severe ECA origin stenosis. An ECA-ICA transposition was performed, primarily to eliminate the risk of emboli and secondarily to possibly improve the STA flow. The patient sustained an excellent radiological and clinical outcome, and the STA donor cut-flow was increased modestly by 22% (45 to 55mL/min). This case is the first report of an ECA to internal carotid artery transposition as an option in the management of ECA stenosis in preparation for an STA-MCA bypass for the purpose of flow augmentation.

External carotid artery stenting in patients with ipsilateral internal carotid artery occlusion: Peri-operative and 12-month follow-up.

This study aimed to evaluate the safety and clinical efficacy of external carotid artery (ECA) stenting in patients with ipsilateral internal carotid artery (ICA) occlusion. In patients with ICA occlusion, severe ipsilateral ECA stenosis may exacerbate pre-existing cerebral ischemia and cognitive impairment. It remains unclear whether ECA stenting to normalize ECA collaterals to the cerebralis alleviates cerebral ischemia and improves cognitive function. From January 2008 to June 2019, we retrospectively collected clinical data of 36 consecutive patients with ipsilateral ICA occlusion who had undergone ECA stenting (mean age, 66.7 ± 8.3 years; males, n = 26 [72.2%]). Neurocognitive test results, including Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MOCA) tests, symptom assessment, and adverse events were recorded. ECA stenting was successful in all 36 patients. Intra-operatively, six (16.7%) patients experienced hemodynamic depression during balloon dilation and recovered completely within 2 days. Within a 12-month follow-up period, two patients experienced a transient ischemic attack, one patient had a contralateral minor stroke, and 33 patients remained asymptomatic. No other adverse events occurred in the peri-operative or follow-up periods. Compared with baseline, significant MMSE (25.3 ± 1.3 vs. 23.6 ± 1.7; p < .05) and MOCA (24.1 ± 1.3 vs. 22.8 ± 1.7; p < .05) test score improvements were observed 3 months post-operatively and were maintained throughout follow-up. ECA stenting may improve cerebral ischemia and cognitive function in patients with severe ECA stenosis and ipsilateral ICA occlusion; however, further research is required to support our findings.

Peak systolic velocity and color aliasing are important in the development of duplex ultrasound criteria for external carotid artery stenosis

ObjectiveThe external carotid artery (ECA) serves as a major collateral pathway for ophthalmic and cerebral artery blood supply. It is routinely examined as part of carotid duplex ultrasound, but criteria for determining ECA stenosis are poorly characterized and typically extrapolated from internal carotid artery data. This is despite the fact that the ECA is smaller in diameter, with a higher resistance and lower volume flow pattern. We hypothesized that using the cutoff of a peak systolic velocity (PSV) ≥125 cm/s, extrapolated from internal carotid artery data, will overestimate the prevalence of ≥50% ECA stenosis and aimed to determine a more appropriate criterion. MethodsFrom December 2016 to July 2017, consecutive carotid duplex ultrasound studies performed in our university hospital Intersocietal Accreditation Commission-accredited vascular laboratory were prospectively identified and categorized with respect to prevalence and distribution of ECA PSVs and color aliasing, an indication of turbulent flow or flow acceleration. Presence of color aliasing was determined by two individual reviewers and agreement assessed by Cohen κ coefficient. ECA stenosis was calculated by the North American Symptomatic Carotid Endarterectomy Trial (NASCET) method in patients with computed tomography angiography (CTA) performed within 3 months of carotid duplex ultrasound without an intervening intervention. Receiver operating characteristic analysis was performed to identify best criteria for determining ≥50% ECA stenosis. ResultsThere were 1324 ECAs from 662 patients analyzed; 174 patients had a total of 252 ECAs with PSV ≥125 cm/s (19% of the total sample). Of those ECAs with PSVs ≥125 cm/s, 30.5% were between 125 and 149 cm/s, 22.2% were between 150 and 174 cm/s, 13.1% were between 175 and 199 cm/s, and 34.1% were ≥200 cm/s. There were 341 ECAs that were analyzed for the presence of color aliasing. In 86 ECAs with PSV ≥200 cm/s, 58.1% had color aliasing, whereas in 255 ECAs with PSV <200 cm/s, only 19.2% had color aliasing (P = .0001). There were 325 CTA studies reviewed and assessed for the presence of a ≥50% ECA stenosis as determined by CTA. Overall, the combination of an ECA PSV ≥200 cm/s with the presence of color aliasing provided the highest combination of sensitivity (90%), specificity (96%), positive predictive value (83%), and negative predictive value (98%) and the greatest area under the curve of 0.971 for determining the presence of a ≥50% ECA stenosis based on CTA. ConclusionsA PSV ≥125 cm/s alone probably overestimates the prevalence of ≥50% ECA stenosis. A PSV ≥200 cm/s combined with color aliasing is highly predictive of >50% ECA stenosis based on correlation with CTA.

External Carotid Artery Stenosis – a duplex ultrasound based study

External Carotid Artery Stenosis – a duplex ultrasound based study

Diameter of External Carotid Arteries in Patients With Mandibular Osteoradionecrosis.

To evaluate the association between osteoradionecrosis (ORN) of the mandible and stenosis of the external carotid artery after radiation therapy (RT) for head and neck cancer. The computed tomography images of 42 patients (36 men, six women; median age, 64.5 years) treated with RT for head and neck cancer between January 2011 and December 2015 were reviewed. The cross-sectional diameters of the bilateral external carotid arteries were measured on contrast-enhanced images taken after completion of RT. Nine of the 42 included patients (21.4%) developed ORN after a median interval of 34 months from completion of RT. Univariate analysis revealed that external carotid artery diameter ≤ the median diameter was significantly associated with ORN development (p=0.008 and 0.013). In multivariate analysis, left external carotid artery diameter ≤ the median was significantly associated with ORN development (p=0.023). External carotid artery stenosis was significantly associated with ORN development.

Duplex Criteria for Grading of External Carotid Stenosis

External carotid artery (ECA) stenosis is an independent mortality predictor. Additionally, concomitant ECA and internal carotid artery (ICA) stenosis progression has been associated with an increased risk of ipsilateral ischemic events in asymptomatic patients. Universally accepted ECA duplex velocity criteria, for the prediction of stenosis, do not exist. Consecutive patients undergoing angiography and carotid duplex assessments were compared (n=140). ICA, common carotid artery (CCA), and ECA peak systolic velocities (PSVs) were recorded. ECA/CCA PSV ratio was calculated. These parameters were compared with angiographic ECA measurements. Receiver-operator curve analysis was used to determine optimal criteria in identifying ECA stenosis of >50%. In patients with little ipsilateral ICA disease, for the detection of ECA stenosis of ≥50%, an ECA PSV >148cm/sec provided a sensitivity of 80%, specificity of 76.2%, and an overall accuracy of 77.1%. An ECA/CCA PSV ratio of 1.45 demonstrated a sensitivity of 73.7%, specificity of 66.7%, and an accuracy of 68.2%.In patients with ICA stenosis ≥50%, for the detection of ECA stenosis of ≥50%, an ECA PSV >179cm/sec provided a sensitivity of 50%, specificity of 79.6%, and overall accuracy of 71.3%. An ECA/CCA PSV ratio of ≥1.89 provided a sensitivity of 71.9%, specificity of 72.7%, and overall accuracy of 72.5%. ECA PSV and ECA/CCA PSV ratios appear as useful metrics for the prediction of unilateral high-grade ECA stenosis.

CME Test for Are You Puzzled When Credentialing Entities Ask You for Criteria for External Carotid Artery Stenosis? A Study Correlating Peak Systolic Velocities and Degree of External Carotid Artery Stenosis Based on CT Angiography

CME Test for Are You Puzzled When Credentialing Entities Ask You for Criteria for External Carotid Artery Stenosis? A Study Correlating Peak Systolic Velocities and Degree of External Carotid Artery Stenosis Based on CT Angiography

Are You Puzzled When Credentialing Entities Ask You for Criteria for External Carotid Artery Stenosis? A Study Correlating Peak Systolic Velocities and Degree of External Carotid Artery Stenosis Based on CT Angiography

External carotid artery (ECA) disease has been understated in the current literature, likely secondary to the lack of clinical neurological symptoms when this vessel is stenotic. However, vascular ultrasound credentialing entities request the adoption of specific criteria for the assessment of the ECA. Our purpose is to determine the ultrasound criteria for the detection of hemodynamically significant stenosis (50%-99%) using computed tomography angiography (CTA) as the reference standard. We included patients who had a carotid ultrasound and a CTA of the neck performed both within a 12-month period. Ultrasound measurements were reviewed for technical accuracy. CTAs were reassessed to determine the degree of stenosis of the bilateral ECAs adopting the North American Symptomatic Carotid Endarterectomy Trial criteria. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were calculated for different peak systolic velocity (PSV) cutoff points to determine the most accurate PSV for detecting 50% to 99% stenosis of the ECA. Receiver operating curve analysis was used to assess diagnostic performance. Of the 536 ECAs included in this study, 13 were noted to be occluded by CTA. Six of these occlusions were accurately detected by ultrasound. There were 82 ECAs with 50% to 99% stenosis on CTA; these vessels had a significantly higher mean PSV compared to ECAs with &lt;50% stenosis (294 vs 122 cm/s) ( P &lt; .0001). A cutoff velocity of ⩾200 cm/s demonstrated a sensitivity, specificity, and overall accuracy of 0.84, 0.93, and 0.91, respectively. Using univariate analysis, smoking was significantly associated with the presence of ⩾50% ECA stenosis. We determined that a PSV cutoff of ⩾200 cm/s showed high sensitivity and specificity for detecting 50% to 99% ECA stenosis based on CTA.

PC182. Development of Duplex Ultrasound Criteria for External Carotid Artery Stenosis: Importance of Assessing Both Peak Systolic Velocity and Presence of Color Aliasing

PC182. Development of Duplex Ultrasound Criteria for External Carotid Artery Stenosis: Importance of Assessing Both Peak Systolic Velocity and Presence of Color Aliasing

Progression of external and internal carotid artery stenosis is associated with a higher risk of ischemic neurologic events in patients with asymptomatic carotid artery stenosis.

A small percentage of patients with asymptomatic carotid artery stenosis (ACAS) who are on optimal medical management do go on to develop ischemic stroke or transient ischemic attacks (IS/TIA). Several diagnostic tools have been studied to identify those patients who are at increased risk. However, most of these diagnostic tools are not available for routine clinical use or are resource intensive. We performed a retrospective study to assess the incremental value of external carotid artery stenosis progression (ECASP) along with internal carotid artery stenosis progression (ICASP) in predicting risk of ipsilateral IS/TIA in a cohort of patients with ACAS. We conducted a retrospective analysis of patients with ACAS who had at least two serial duplex ultrasounds (DUS) at our center. A total of 356 patients (712 carotid arteries) were included in the study (mean age 74.7±9 years, 49.2% male) with a mean follow-up of 60.7±32.7 months. In univariate analysis, concurrent progression of ICA and ECA stenosis on the same side arteries was associated with a very significant increased risk of ipsilateral IS/TIA (14.7% vs 4.6%, p<0.001). Also, multivariable regression analysis showed that concurrent ECA/ICA progression was an independent predictor of IS/TIA (OR=3.6, 95% CI 1.64-7.8; p=0.001). ECASP along with ICASP is significantly associated with increased risk of ipsilateral IS/TIA and provides incremental risk stratification over that provided by ICASP alone. The ECA is routinely evaluated in clinical practice, and it could serve as an additional marker for identifying higher risk patients with ACAS.

Transverse Cervical Artery: Consistent Anatomical Landmarks and Clinical Experience with Its Use as a Recipient Artery in Complex Head and Neck Reconstruction.

Many head and neck reconstructions occur in patients with extensive history of surgery or radiation treatment. This leads to complicated free flap reconstructions, especially in choosing recipient vessels in a "frozen neck." The transverse cervical artery is an optimal second-line recipient artery in head and neck reconstruction. Seventy-two neck sides in 36 cadavers were dissected, looking for the transverse cervical artery and transverse cervical vein. Anatomical location of these vessels, their diameter, and length were documented. A retrospective analysis on 19 patients who had head and neck reconstruction using the transverse cervical artery as a recipient artery was undertaken as well with regard to outcome of procedures, reason for surgery, previous operations, and use of vein grafts during surgery. The transverse cervical artery was present in 72 of 72 of cadaveric specimens, and was infraclavicular in two of 72 specimens. Transverse cervical artery length ranged from 4.0 to 7.0 cm, and the mean diameter was 2.65 mm. The transverse cervical vein was present in 61 of 72 cadaveric specimens, the length ranged from 4.0 to 7.0 cm, and the mean diameter was 2.90 mm. The transverse cervical artery averaged 33 mm from midline, and branched off the thyrocervical trunk at an average 17 mm superior to the clavicle. Transverse cervical artery stenosis was markedly less in comparison with external carotid artery stenosis. In a 20-year clinical follow-up study, the transverse cervical artery was the recipient artery in 19 patients. A vein graft was used in one patient, and no flap loss occurred in any of the 19 patients. The transverse cervical artery is a reliable and robust option as a recipient artery in free flap head and neck reconstruction.

Fluid-Structure Interaction Study of Stenotic Flow in Subject Specific Carotid Bifurcation—A Case Study

Advances in numerical simulation have allowed the investigation of complex interaction of blood flow through elastic arteries which can be useful in demonstrating the disease progression and haemodynamics of cardiovascular diseases such as atherosclerosis. In the present study, patient is diagnosed with an occluded right Internal Carotid Artery (ICA) with partial stenosis at root of right External Carotid Artery (ECA) and partial stenosis at the root of left ICA. 3D patient specific carotid bifurcation is generated based on CT scan data using MIMICS-14.0 and numerical analysis is performed using FSI in ANSYS-14.5. The blood flow is assumed to be incompressible, homogenous and Newtonian, while artery wall is assumed to behave linearly elastic. The two-way sequentially coupled transient FSI analysis is performed using FSI solver for three pulse cycles and haemodynamic parameters such as flow pattern, Wall Shear Stress (WSS), pressure contours and arterial wall deformation are studied at the bifurcation and critical zones. The variation in flow behavior is investigated throughout the pulse and simulation results obtained reveals that there is a considerable increase in the flow behavior in partially stenosed carotid unlike occluded carotid. The investigation also demonstrates disturbed flow pattern especially at the bifurcation and stenosed zone elevating the haemodynamic variation during peak systole and later part of pulse cycle. The obtained results agree well with the clinical observation and demonstrate the potential of patient specific numerical studies in prognosis of disease progression and plaque rupture

OS 18-02 ANTIHYPERTENSIVE TREATMENT AND RISK OF BRAIN ISCHEMIA DUE TO CAROTID STENOSIS IN A SURVEY OF HOSPITALISED PATIENTS AGED 90 YEARS AND OLDER

Objective: In elderly hypertensive patients, systolic blood pressure (sBP) goals recommended by US and European guidelines (ESH) for the initiation of treatment are more liberal than in younger patients because of an increased risk of treatment-associated side-effects and hypotension. Carotid stenosis increases with age and poses a risk of brain ischemia if hypotension occurs. Its relevance for the routine care of elderly hypertensives, however, remains unclear. We analyzed data on precerebral artery morphology and BP evolution from a survey of aged hospitalized patients. Design and Method: All patients ≥ 90 years admitted to the medical ward of a primary care hospital were prospectively included over 15 months. Ultrasound exams of the precerebral arteries were performed for routine evaluation of cardiovascular risk. Intima-media thickness (IMD) of the common carotid arteries (CCA) and internal and external carotid artery (I/ECC) stenosis were analyzed together with BPs (admission and discharge). Patients who died, with circulatory shock and readmissions were excluded (n = 9). Results: Sixty-three patients aged 92 ± 3 years (mean ± SD; range 90–101) with a median hospital stay of 11 days were analyzed (78% female, 35% diabetics, 24% atrial fibrillation, 41% coronary heart disease). On admission, 76% were on antihypertensive drugs and 43% had their number changed. Mean BP was 149/88 mmHg (36% sBP < 140 mmHg) vs. 129/72 mmHg at discharge (64% sBP <140 mmHg; p<0.05). Mean IMD (right/left) was 8.7/9.4 mm. Frequencies of non-stenotic plaque were: CCA 13/16%, ICC 13/16%, ECC 19/29%, bulb 62/70%; of ICC stenosis (≥ 60%) 5/5%, ECC stenosis (≥ 60%) 10/19%, ICC occlusion 2/2%, bilateral ICC stenosis 2% (1/63); none with bilateral ICC occlusion. Conclusions: In very old treated hypertensive patients, the risk of carotid stenosis-associated brain ischemia appears to be very low compared to stroke risk by the global burden of atrial fibrillation. Concerning carotid stenosis, sBP targets < 140 mmHg should be safe for the majority of nonagenarians.

Anterior temporal artery tap to identify systemic interference using short-separation NIRS measurements: A NIRS/EEG-tDCS study.

Transcranial direct current stimulation (tDCS) has been shown to modulate neural activity. Neural activity has been shown to be closely related, spatially and temporally, to cerebral blood flow (CBF) that supplies glucose via neurovascular coupling. Therefore, noninvasive and continuous monitoring of neural activity is possible with a measure of cerebral hemoglobin oxygenation using near-infrared spectroscopy (NIRS). In principal accordance, NIRS can capture the hemodynamic response to tDCS but the challenge remains in removing the systemic interference occurring in the superficial layers of the head that are also affected by tDCS. An approach may be to use short optode separations to measure systemic hemodynamic fluctuations occurring in the superficial layers which can then be used as regressors to remove the systemic contamination. Here, we demonstrate that temporal artery tap may be used to better identify systemic interference using this short-separation NIRS. Moreover, NIRS-EEG joint-imaging during anodal tDCS was used to measure changes in mean cerebral haemoglobin oxygen saturation (rSO2) along with changes in the log-transformed mean-power of EEG within 0.5 Hz-11.25 Hz. We found that percent change in the mean rSO2 better correlated with the corresponding percent change in log-transformed mean-power of EEG within 0.5 Hz-11.25 Hz frequency band after removing the systemic contamination using the temporal artery tap method. Based on our findings, we propose that anterior temporal artery tap technique presented in this paper may be able to classify carotid stenosis, external carotid artery stenosis, and internal carotid artery stenosis patients using the laterality in the hemodynamic response evoked by anodal tDCS both at the brain as well as at the superficial layers. These findings may have important implications for both prognosis and rehabilitation of patients with intracranial stenosis.