Ipsilateral Middle Cerebral Artery Research Articles

Decreased flow in ischemic stroke with coexisting intracranial artery stenosis and white matter hyperintensities.

Stroke patients with coexisting intracranial artery stenosis (ICAS) and white matter lesions (WML) usually have a poor outcome. However, how WML affects stroke prognosis has not been determined. To investigate the quantitative forward flow at the middle cerebral artery in ICAS patients with different degrees of WML using 4D flow. Single-center cross-sectional cohort study. Ischemic stroke patients with symptomatic middle cerebral artery (MCA) atherosclerosis were included, and they were divided into 2 groups based on Fazekas scale on Flair image (mild group = Fazekas 0-2, and severe group = Fazekas >2), TOF-MRA and 4D flow were performed to quantify the stenosis degree and forward flow at the proximal of stenosis. The flow parameters were compared between different white matter hyperintensity (WMH) groups, as well as in different MCA stenosis groups, logistic regression was used to validate the association between forward flow and WMH. A total of 66 patients were included in this study (mean age 56 years old, 68.2% male). 77.3% of them presented with WMH (Fazekas 1-5). Comparison of flow index between mild and severe WMH groups found a significantly lower forward flow (2.34 ± 1.09 vs 3.04 ± 1.35), higher PI (0.75 ± 0.43 vs 0.66 ± 0.32), and RI (0.49 ± 0.19 vs 0.46 ± 0.15) at ipsilateral infarction MCA in the severe WMH group, all P-values <0.05. After adjusting for other covariates, forward mean flow at ipsilateral infarction MCA is still associated with severe WMH independently, OR = 0.537, 95% CI (0.294, 0.981), P = 0.043. Intracranial artery stenosis patients with coexisting severe WMH suffer from significantly decreased flow, which could explain the poor clinical outcome in this population, and also provide some insight into recanalization therapy in the future.

The Circle of Willis Status Influences Neurological Complications of Carotid Endarterectomy with Contralateral Carotid Occlusion

ObjectiveTo evaluate the impact of anatomical variations in the Circle of Willis (CoW) on immediate neurological events (INE) after carotid endarterectomy (CEA) without shunting in patients with contralateral carotid occlusion (CCO). Materials and MethodsSingle centre, retrospective study. Patient’s demographic and clinical outcomes data were prospectively collected. CoW segments were reviewed retrospectively. Between January 2013 and May 2018, 2090 patients underwent CEA under general anaesthesia, CCO was found in 113 (5.4%) patients. CoW segments were classified as normal, hypoplastic (diameter ˂ 0.8 mm), or absent based on Computed Tomography Angiography (CTA). We studied the CoW segments as two collateral networks connecting the basilar artery and the ipsilateral middle cerebral artery (MCA): a short semicircle (first segment of the ipsilateral posterior cerebral artery [P1] and posterior communicating artery [Pcom] segment) and a long semicircle (contralateral P1, Pcom, and both first segments of the anterior cerebri artery (A1) anterior communicating artery (Acom)). INE was defined as any transient ischemic attack (TIA) or stroke diagnosed immediately after the procedure. ResultsOut of the 113 patients, 46 underwent endarterectomy with shunting. We further excluded 16 patients from the assessment of the CoW due to unavailability or inadequate quality of CTA. Of the 113 patients, 2 had strokes, one with shunting that occurred hours after surgery. Besides the other stroke case, 4 INE were observed, all without the use of a shunt. Of the 51 patients with CoW assessment, 10 (19.6%) had a complete CoW, while 21 (41.2%) patients had only one semicircle intact (10 short and 11 long intact semicircles), and none of these patients experienced an INE. A total of 20 (39%) patients had both the long and short semicircles incomplete, of which 4 (7.8%) cases had an INE. In all INE cases, at least one of the Pcom was absent or hypoplastic. The absence of both Pcom was a strong predictor of incident INE [odds ratio=11.10 (confidence interval: 1.04-118.60)] for INE. ConclusionPatients with CCO and insufficient CoW collateral flow support are at an increased risk of INE, including stroke, in the absence of shunt protection during CEA cross-clamping. Shunting should always be considered when the collateral flow between the ipsilateral MCA and the basilar artery is compromised in CCO patients.

Exploring the relationship between embolic acute stroke distribution and supra-aortic vessel patency: key findings from an in vitro model study

BackgroundWe investigated differences in intracranial embolus distribution through communicating arteries in relation to supra-aortic vessel (SAV) patency.MethodsFor this experimental analysis, we created a silicone model of the extracranial and intracranial...

Triplicated middle cerebral arteries (duplicated and ipsilateral accessory) associated with triplicated anterior cerebral arteries (accessory) diagnosed by magnetic resonance angiography.

To describe a case of duplicated middle cerebral artery (MCA) combined with ipsilateral accessory MCA, forming a triplicated MCA, associated with the accessory anterior cerebral artery (ACA), forming a triplicated A2 segment of the ACA detected incidentally on magnetic resonance (MR) angiography. A 70-year-old woman with internal carotid artery (ICA) stenosis at the origin, which was detected by ultrasound, underwent cranial MR imaging and MR angiography of the intracranial region for an evaluation of brain and cerebral arterial lesions. The MR machine was a 3-Tesla scanner. MR angiography was performed using a standard 3-dimensional time-of-flight technique. Multiple ischemic white matter lesions are observed. No significant stenotic lesions were observed in intracranial arteries. The right duplicated MCA was originated from right distal ICA. And main MCA was originated from right ICA bifurcation. Right accessory MCA was arisen from the A2 segment of the right ACA. Thus, the right MCA was triplicated. There was also an accessory ACA forming a triplicated ACA at its A2 segment. These findings were clearly identified on partial volume-rendering (VR) images. We herein report a case of triplicated MCA associated with triplicated ACA. MCA variations are relatively rare, and this is the third case of triplicated MCA reported in relevant English-language literature. To identify multiple cerebral arterial variations, creating partial VR images using MR angiographic source images is useful.

Geometry and Symmetry of Willis' Circle and Middle Cerebral Artery Aneurysms Development.

Background: A relationship between the geometry and symmetry of Willis' circle and intracranial aneurysms was reported for anterior communicating and posterior communicating (PCom) aneurysms. A similar association with the middle cerebral artery (MCA) aneurysms instead appeared weaker. Methods: We reviewed 432 patients from six Italian centers with unilateral MCA aneurysms, analyzing the relationship between the caliber and symmetry of Willis' circle and the presence of ruptured and unruptured presentation. CT-angiograms were evaluated to assess Willis' circle geometrical characteristics and the MCA aneurysm side, dimension and rupture status. Results: The hypoplasia of the first segment of the anterior cerebral artery (A1) was in approximately one-quarter of patients and PCom hypoplasia was in almost 40%. About 9% had a fetal PCom ipsilaterally to the aneurysm. By comparing the aneurysmal and healthy sides, only the PCom hypoplasia appeared significantly higher in the affected side. Finally, the caliber of the internal carotid artery (ICA) and the first segment of MCA (M1) caliber were significantly greater in patients with unruptured aneurysms, and PCom hypoplasia appeared related to the incidence of an ipsilateral MCA aneurysm and its risk of rupture. Conclusions: Although according to these findings asymmetries of Willis' circle are shown to be a risk factor for MCA aneurysm formation and rupture, the indifferent association with ipsilateral or contralateral hypoplasia remains a datum of difficult hemodynamic interpretation, thereby raising the concern that this association may be more casual than causal.

NONINVASIVE DIAGNOSTICS OF EXTRACRANIAL ARTERIES TORTUOSITY

Deformations of carotid artery – deviation, tortuosity, coiling, hold the 2nd placeamong other carotid pathologies. They are the cause of 10-17% of cerebrovasculardisorders. It should also be noted that this pathology is common for a relatively youngage. It is considered that in the elderly carotid deformation is an acquired lesion mostcommonly seen in patients suffering from arteriosclerosis and hypertension, while inchildren and younger patients, the kinks and coils are congenital. For diagnostics ofdeformations of magistral arteries, highly efficient non-invasive methods are applied:ultrasound duplex-scanning, MR angiography, and multi-slice CT angiography. We havestudied deformations of magistral carotid and vertebral arteries in cases of isolatedatherosclerosis, isolated arterial hypertension, and a combination of atherosclerosisand hypertension. Out of 205 patients we diagnosed deformations of carotid arteriesin 93 (30%) cases, and deformations of vertebral arteries in 64 (21%) cases. Bilateraldeformation of carotid arteries was diagnosed in 43 (17%) cases. C- or S-shaped deformationsin 55 (81%) cases were located in proximal or medial parts of CCA or ICA. 76%of patients with this pathology had arterial hypertension. In the case of C- or S-typedeformation rate amounted to 30%, in the case of coiling increase of flow it reached50%, and in the case of kinking – exceeded 60%. In the case of C- or S-type elongation,flow volume (Q) is practically within the normal range - 488±38 ml/min. In the case ofspiral shape elongation, it showed the tendency of decrease -402±22 ml/min, which ismore obvious in the case of kinking - 332±22 ml/min. The frequency of elongations ispractically the same in the case of isolated atherosclerosis or hypertension, however,in the case of their combination the frequency increases. In order to study the impactof the deformation of magistral arteries on intracranial hemodynamics, we examined84 patients without any hemodynamically significant atherosclerotic pathology of carotids.We found a total of 91 elongations: In the case of C- or S-shaped deformation,flow parameters remain within the normal range, as in the case of spiral elongation orcoiling. In the case of kinking, there is an obvious tendency for a decrease in flow rate – the average flow rate is 20% below the normal value. Our data correspond to similar data of other authors, who revealed the tendency of a 20-35% decrease of flow rate in the ipsilateral middle cerebral artery, in case of significant tortuosity or kinking of the carotid artery.

Abstract TP206: Transcranial Doppler Markers of Increased Microvascular Resistance After Successful Endovascular Revascularization Are Associated With Larger Infarct Volumes

Background: Markers of increased microvascular resistance on Transcranial Doppler (TCD) obtained shortly after successful endovascular therapy (EVT) in patients with large-vessel occlusion (LVO) stroke have been associated with unfavorable outcomes. We aim to investigate whether post-EVT pulsatility index (PI) correlates with final infarct volume in this population. Methods: We analyzed consecutive anterior circulation LVO patients who underwent successful EVT (mTICI 2c-3) from 2012 to 2022. Patients with available TCD within 48 hours of EVT and brain MRI during admission were included. The TCD-derived PI was obtained from the ipsilateral middle cerebral artery. The ABC/2 method was used to estimate the final infarct volume in mL on MRI diffusion-weighted imaging. Pearson correlation and adjusted linear regression analysis were used to investigate the relationship between post-EVT PI and final infarct volume. Linear regression analysis was adjusted for age, NIHSS, and ASPECTS. Results: Out of 155 LVO patients with successful EVT during the study period, 40 were included in the analysis (mean age, 69 ± 16.7 years; 57% female; median NIHSS 15 (IQR 10); and median ASPECTS 9 (IQR, 2)). The median time from EVT to TCD and EVT to MRI was 21 hours (IQR, 17 hours) and 41 hours (IQR, 33 hours), respectively. Post EVT PI displayed a positive moderate correlation with final infarct volume (r=0.39, p&lt;0.01; Figure 1). Larger PI values were independently associated with larger infarct volumes (β = 42.2 mL, 95% CI 37.0 - 47.5 mL). Conclusion: TCD-derived PI shortly after EVT correlated with final infarct volume in successfully revascularized LVO patients. TCD may serve as a valuable tool to identify those at risk for infarct progression and reveal potential therapeutic targets to maximize EVT benefit in this population.

Cerebral Blood Flow Patterns in Patients With Low-Flow Carotid Artery Stenosis, a 4D-PCMRI Assessment.

Compromised cerebral blood flow can contribute to future ischemic events in patients with symptomatic carotid artery disease. However, there is limited knowledge of the effects on cerebral hemodynamics resulting from a reduced internal carotid artery (ICA) blood flow rate (BFR). Investigate how reduced ICA-BFR, relates to BFR in the cerebral arteries. Prospective. Thirty-eight patients, age 72 ± 6 years (11 female). 3-Tesla, four-dimensional phase-contrast magnetic resonance imaging (4D-PCMRI). Patients with ischemic stroke or transient ischemic attack were evaluated regarding the degree of stenosis. 4D-PCMRI was used to measure cerebral BFR in 38 patients with symptomatic carotid stenosis (≥50%). BFR in the cerebral arteries was assessed in two subgroups based on symptomatic ICA-BFR: reduced ICA-flow (<160 mL/minutes) and preserved ICA-flow (≥160 mL/minutes). BFR laterality was defined as a difference in the paired ipsilateral-contralateral arteries. Patients were grouped based on ICA-BFR (reduced vs. preserved). Statistical tests (independent sample t-test/paired t-test) were used to compare groups and hemispheres. Significance was determined at P < 0.05. The degree of stenosis was not significantly different, 80% (95% confidence interval [CI] = 73%-87%) in the reduced ICA-flow vs. 72% (CI = 66%-76%) in the preserved ICA-flow; P = 0.09. In the reduced ICA-flow group, a significantly reduced BFR was found in the ipsilateral middle cerebral artery and anterior cerebral artery (A1), while significantly increased in the contralateral A1. Retrograde BFR was found in the posterior communicating artery and ophthalmic artery. Significant BFR laterality was present in all paired arteries in the reduced ICA-flow group, contrasting the preserved ICA-flow group (P = 0.14-0.93). 4D-PCMRI revealed compromised cerebral BFR due to carotid stenosis, not possible to detect by solely analyzing the degree of stenosis. In patients with reduced ICA-flow, collaterals were not sufficient to maintain symmetrical BFR distribution to the two hemispheres. 2 TECHNICAL EFFICACY: Stage 3.

Absence of periictal hyperperfusion on arterial spin labeling perfusion images in a patient with posttraumatic epilepsy and underdevelopment of ipsilateral internal carotid and middle cerebral arteries

Absence of periictal hyperperfusion on arterial spin labeling perfusion images in a patient with posttraumatic epilepsy and underdevelopment of ipsilateral internal carotid and middle cerebral arteries

The Positional Relationship between Lacunae and White Matter Hyperintensity in Patients with Cerebral Small Vessel Disease.

Lacunae and white matter hyperintensity (WMH) are two crucial imaging biomarkers of cerebral small vessel disease (CSVD). Multiple studies have revealed a close relationship between WMH and lacunae and found that a double penumbra existed at the edge of WMH that affects lacunae formation. The study aimed to explore the spatial distribution characteristics and possible influencing factors of lacuna in relation to white matter hyperintensity in patients with CSVD. A total of 480 CSVD patients with WMH and with or without lacunae were included. Data about blood biochemical indicators, cerebrovascular CT angiography, 24-hour ambulatory blood pressure and ambulatory electrocardiogram, brain magnetic resonance imaging, and transcranial Doppler ultrasound were gathered from all subjects. They were categorised into four groups based on the spatial interaction between lacunae and WMH. Univariate analyses and multiple logistic regression analyses were used to compare the differences in traditional vascular risk factors, heart rate and blood pressure indicators, arterial pulsatility index (PI) values, and arterial stenosis among different groups. The average age of 480 patients was (58.63 ± 11.91) years, with 347 males (72.3%). Univariate analysis indicated that age, fasting blood glucose, triglycerides, total cholesterol, highdensity lipoprotein, 24-hour and daytime and night systolic and diastolic blood pressure, nocturnal heart rate, heart rate variability, PI values of ipsilateral and contralateral MCA (middle cerebral artery) and ICA (Internal carotid artery) of the lacunae, Fazekas score of PWMH (periventricular white matter hyperintensities), the proportion of MCA or ICA with stenosis rate over 50% on the ipsilateral side of the lacunae were significantly different between different groups (p < 0.05). High fasting blood glucose (OR=1.632, 95% CI= (1.128, 2.361), p =0.009), (OR=1.789, 95%CI= (1.270, 2.520), p = 0.001), (OR=1.806, 95% CI= (1.292, 2.524), p =0.001) was identified as a risk factor for lacunae formation by logistic regression analysis. High fasting blood glucose can be considered a risk factor for lacunae formation in patients with WMH. The more severe the PWMH and the higher the nocturnal heart rate, the more likely the lacunae, as well as PWMH, overlap completely. Ipsilateral arteriosclerosis and stenosis are independent risk factors for no contact between lacunae and PWMH.

Intracranial Atherosclerotic Stenosis Is Associated with Cognitive Impairment in Patients with Nondisabling Ischemic Stroke: A pCASL-Based Study.

Background: Intracranial atherosclerotic stenosis (ICAS) is a key risk factor for vascular cognitive impairment. Cerebral blood flow (CBF) and the spatial coefficient of variation (sCoV) of CBF images (based on pseudocontinuous arterial spin labeling) are used to explore abnormal cerebral perfusion. We aimed to probe the mechanisms underlying cognitive impairment in patients with nondisabling anterior circulation macrovascular disease. Methods: This study included 47 patients with ICAS or occlusion and 40 controls. All participants underwent global and individual neuropsychology assessments and magnetic resonance imaging scan. The correlations between cognitive function and abnormal perfusion were explored. Results: The CBF in the ipsilateral middle cerebral artery (MCA) territory of the lesion side decreased significantly, while it increased on the contralateral side. CBF value had a significant correlation with the memory function in the right cerebral artery lesion group. The sCoV in both gray matter (GM) and the ipsilateral MCA territory of the lesion increased significantly. The sCoV value based on the GM territory or MCA territory was significantly correlated with global cognitive function, memory function, and executive function in patients with ICAS. Conclusions: The cognitive function of patients with severe ICAS or occlusion in anterior circulation was significantly impaired. sCoV could be a better indicator of cognitive impairment than CBF. Interventions to relieve vascular stenosis or occlusion and delay cognitive impairment or improve cognitive function should be actively considered. Impact statement Intracranial atherosclerotic stenosis (ICAS) is a key risk factor for stroke and vascular cognitive impairment (VCI). VCI seriously affects the physical and mental health of patients and their caregivers, significantly increasing the social burden. The most direct changes in patients with ICAS are the decrease of cerebral blood flow in the blood supply area and the abnormality of local or whole cerebral perfusion. This study explores the relationship between abnormal cerebral perfusion and cognitive impairment in patients with ICAS, which helps to increase the attention paid to VCI and promote the improvement of diagnosis and treatment measures.

Transcranial Doppler After Successful Endovascular Revascularization and Hospitalization Outcomes

Background Almost half of large‐vessel occlusion strokes have unfavorable outcomes despite successful endovascular therapy. We aim to investigate whether postrevascularization cerebral hemodynamics, determined by transcranial Doppler (TCD), associate with hospitalization outcomes in this population. Methods The current observational cohort study analyzed 155 patients with successfully revascularized anterior circulation large‐vessel occlusion stroke (mean age, 68.3±15.4 years; 55% women) who had TCD within 48 hours from endovascular therapy. TCD parameters (mean flow velocity, peak systolic velocity, and pulsatility index) were recorded at the ipsilateral middle cerebral artery, and blood flow signals were categorized using the Thrombolysis in Brain Ischemia grades into normal (grade 5), stenotic (grade 4), or dampened (grade ≤3). Hospitalization outcomes comprised favorable discharge modified Rankin Scale score (0–2), favorable discharge destination (home or acute inpatient rehabilitation), and in‐hospital mortality. Logistic regression models adjusted for age, initial National Institutes of Health Stroke Scale score, and Alberta Stroke Program Early CT [Computed Tomography] Score were fit to determine TCD findings in association with study outcomes. Results Abnormal TCD‐derived blood flow was found in 54 (35%) cases, including 35 (23%) with Thrombolysis in Brain Ischemia grade 4 and 19 (12%) with Thrombolysis in Brain Ischemia grade ≤3. Overall, 31% had favorable discharge modified Rankin Scale score, 65% had favorable destination, and 14% died. Thrombolysis in Brain Ischemia grade ≤3 was associated with lower likelihood of both favorable discharge modified Rankin Scale score (adjusted odds ratio [OR], 0.09 [95% CI, 0.01–0.81]) and favorable destination (adjusted OR, 0.22 [95% CI, 0.07–0.71]). Mean flow velocity and peak systolic velocity were not associated with study outcomes. Conversely, increased pulsatility index was inversely associated with favorable destination (adjusted OR, 0.34 [95% CI, 0.13–0.87]). Conclusions TCD after successful endovascular therapy identified abnormal blood flow in one‐third of cases. Dampened flow and markers of increased microvascular resistance were associated with unfavorable hospitalization outcomes. TCD could provide valuable prognostic information in this population and identify potential therapeutic targets.

A randomized, double-blind, placebo-controlled, multicenter trial- DL-3-n-butylphthalide therapy for cerebral hypoperfusion from unilateral internal carotid system stenosis study: study protocol

Background: Cerebral hypoperfusion caused by large-vessel stenosis is an important risk factor for ischemic stroke and vascular cognitive impairment. In vitro, animal and clinic studies demonstrated that DL-3-n-butylphthalide (NBP) can improve the collateral circulation and the cerebral perfusion. In this trial, the benefit of NBP to ameliorate the chronic cerebral hypoperfusion resulting from unilateral internal carotid system stenosis will be explored. Methods: This trial is a randomized, double-blind, placebo-controlled, multicenter clinical study. A total 480 subjects with ≥70% stenosis or occlusion in unilateral internal carotid artery system, cerebral hypoperfusion in the ipsilateral middle cerebral artery (MCA) territory, and no transient ischemic attacks (TIA) or ischemic strokes within 2 weeks will be enrolled in China. Patients will be assigned in a 1:1 ratio to NBP and placebo groups. Patients in NBP or placebo group received 200 mg or 20 mg of NBP capsules three times daily for 4 weeks respectively. The cerebral perfusion will be assessed again after 12 weeks. The primary efficacy outcome is the proportion of patients with cerebral blood flow (CBF) amelioration, stabilization and deterioration after treatment. Conclusions: This trial will provide a high-level of evidence for NBP to treat the cerebral hypoperfusion, and a novel strategy to improve the cerebral hemodynamic impairment due to large intracranial and extracranial atherosclerotic stenosis in the surgical high-risk patients, especially in the aged and Asians. Trial registration: This trial is registered as ChiCTR2100053112 on November 12th, 2021.

Determination of the Unilaterally Damaged Region May Depend on the Asymmetry of Carotid Blood Flow Velocity in Hemiparkinsonian Monkey: A Pilot Study.

The hemiparkinsonian nonhuman primate model induced by unilateral injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) into the carotid artery is used to study Parkinson's disease. However, there have been no studies that the contralateral distribution of MPTP via the cerebral collateral circulation is provided by both the circle of Willis (CoW) and connections of the carotid artery. To investigate whether MPTP-induced unilaterally damaged regions were determined by asymmetrical cerebral blood flow, the differential asymmetric damage of striatal subregions, and examined structural asymmetries in a circle of Willis, and blood flow velocity of the common carotid artery were observed in three monkeys that were infused with MPTP through the left internal carotid artery. Lower flow velocity in the ipsilateral common carotid artery and a higher ratio of ipsilateral middle cerebral artery diameter to anterior cerebral artery diameter resulted in unilateral damage. Additionally, the unilateral damaged monkey observed the apomorphine-induced contralateral rotation behavior and the temporary increase of plasma RANTES. Contrastively, higher flow velocity in the ipsilateral common carotid artery was observed in the bilateral damaged monkey. It is suggested that asymmetry of blood flow velocity and structural asymmetry of the circle of Willis should be taken into consideration when establishing more efficient hemiparkinsonian nonhuman primate models.

Post-reperfusion hyperperfusion after endovascular stroke treatment: a prospective comparative study of TCD versus MRI

BackgroundIncreased middle cerebral artery (MCA) blood flow velocities on transcranial duplex sonography (TCD) were recently reported in individual patients after successful mechanical thrombectomy (MT) and were related to intracranial hemorrhage...

Postoperative vascular event prediction using angiography and ultrasonography in patients with Moyamoya disease

ObjectiveIndirect revascularization surgery reduce the risk of recurrent vascular events in patients with moyamoya disease (MMD), but the roles of postoperative angiography and ultrasonography in predicting these events remain unclear. MethodsThis prospective study enrolled patients with MMD who would undergo their first unilateral indirect revascularization surgery. They received preoperative and postoperative ultrasound examination at 1, 3, and 6 months and conventional cerebral angiography. On ultrasonography, postoperative emerging flow (PEF) in an intracranial artery was defined as emerging flow postoperatively with absence of flow preoperatively. Predictors of vascular event frequency reduction were identified from angiographic and ultrasonographic parameters. ResultsIn total, 52 patients (including 24 pediatric and 24 male patients), who underwent 52 preoperative and 82 postoperative ultrasound examinations, were enrolled. Significant postoperative changes were noted in all the ultrasonographic parameters of ipsilateral superficial temporal artery (STA) and the end-diastolic velocity and flow volume in contralateral STA. During a median follow-up of 5.3 years, indirect revascularization surgery significantly reduced the occurrence of ipsilateral vascular events. Predictors of vascular event frequency reduction included Matsushima grade A or B on the ipsilateral side on angiography (odds ratio [OR] = 22.00, P = 0.002) and lower resistance index (RI) in ipsilateral STA (OR = 0.0001, P = 0.012) but no PEF pattern in ipsilateral middle cerebral artery (OR = 0.14, P = 0.029) on ultrasonography performed within 6 months. ConclusionsReduction of long-term vascular event frequency probably can be predicted through postoperative angiography and ultrasonography within 6 months after indirect revascularization surgery.

Association of carotid artery geometries with middle cerebral artery atherosclerosis

Background and aimsEvidence shows that artery geometries play a role in atherogenesis by influencing blood flow dynamics. However, whether upstream artery geometries influence downstream atherosclerosis remains unclear. We aimed to investigate whether carotid artery geometries were associated with middle cerebral artery (MCA) atherosclerosis. MethodsWe reviewed our institutional database of 3-dimensional head-neck combined high-resolution magnetic resonance imaging. The carotid artery geometries, carotid atherosclerosis, MCA configurations, and MCA atherosclerosis were examined. The associations between carotid artery geometry and MCA atherosclerosis were also analyzed. A final model integrating carotid artery geometries was established, and the incremental diagnostic value was evaluated and compared to a basic model that included only traditional risk factors. ResultsAmong the 575 artery units of the ipsilateral carotid artery and MCA, the artery units with MCA plaques (n = 273) were associated with a larger bifurcation angle (odds ratio [OR], 1.138 per 10-degree increase; 95% confidential interval [CI], 1.023–1.264) and kinking-type extracranial internal carotid artery (ICA; OR, 2.193; 95%CI, 1.283–3.748) compared with those without MCA plaques (n = 302). These associations were independent of traditional risk factors, carotid atherosclerosis, and MCA configuration. A larger carotid bifurcation angle was also associated with tandem ICA and MCA atherosclerosis (OR, 1.211 per 10-degree increase; 95%CI, 1.110–1.321). The incremental diagnostic value of carotid artery geometry to traditional risk factors was revealed by comparing the area under the curves of the two diagnostic models (basic model, 0.673 vs. final model, 0.701; p = 0.016). ConclusionsCarotid artery geometries are independently associated with ipsilateral MCA atherosclerosis, providing new insights into the pathophysiology of intracranial atherosclerosis.

One-Stage Revascularization to the Ipsilateral Middle Cerebral Artery and Contralateral Anterior Cerebral Artery Territories

Patients with multiple intracranial atherosclerotic stenoses often present with hemodynamic instability in 2 remote regions without a reciprocal vascular network. In this situation, revascularization to each region may be required. In this report, 2 patients who had coexisting unilateral middle cerebral artery (MCA) and contralateral anterior cerebral artery territory ischemia were treated by using ipsilateral superficial temporal artery (STA)-radial artery graft-contralateral A3 bypass and ipsilateral STA-MCA bypass in one stage. Postoperatively, the bypass conduit was well established, and the patients' hemodynamic instability was improved. In patients with severe hemodynamic instability in the remote unilateral MCA and contralateral anterior cerebral artery regions, as in our 2 cases, ipsilateral STA-MCA and ipsilateral STA-radial artery graft-contralateral A3 bypasses in one stage can be a treatment option.

TCD hemodynamics findings in the subacute phase of anterior circulation stroke patients treated with mechanical thrombectomy.

Despite mechanical thrombectomy, the prognosis for many patients with anterior circulation ischemic stroke (ACIS) remains poor. This retrospective study reports consecutive mechanical thrombectomy procedures for ACIS at our hospital over 4 years. Hemodynamics were explored using transcranial Doppler ultrasound. The functional outcome was assessed using the modified Rankin scale. A total of 121 eligible cases were included: 61 (50.4%) exhibited good outcomes (modified Rankin scale score ≤2) by day 90. The logistic regression analysis showed that ipsilateral middle cerebral artery (iMCA) systolic blood flow (SBF) (OR = 0.983, 95% CI: 0.969–0.997, P = 0.014), preoperative National Institutes of Health Stroke Scale (NIHSS)score (OR = 1.160, 95% CI: 1.067–1.261, P < 0.001), intracranial hemorrhage after therapy (OR = 19.514, 95% CI: 4.364–87.265, P < 0.001), and Alberta Stroke Program Early Computed Tomography Score (OR = 0.639, 95% CI: 0.416–0.981, P = 0.040) were independently associated with prognosis. The iMCA SBF and preoperative NIHSS score were significantly predictive of a good outcome in the receiver operating characteristic analysis. In conclusion, elevated iMCA SBF might be a prognostic indicator of a good 90-day outcome following endovascular treatment in ACIS patients treated with mechanical thrombectomy, but large prospective studies are mandatory to validate the findings of our study.

Investigation of Flow Changes in Intracranial Vascular Disease Models Constructed with MRA Images.

This study aimed to develop a magnetic resonance imaging (MRI)-compatible flow delivery system and individualized models of circle of Willis (CoW), which include 50% and 100% blockage in internal carotid artery (ICA50 and ICA100), and 100% blockage in vertebral artery (VA100). Images were obtained using 3D time-of-flight and phase-contrast magnetic resonance angiography (MRA) sequences, and changes in velocity and flow direction at CoW models were analyzed. For the ICA50 and VA100 models, the flow was similar to that of the normal model. For the ICA 50 model, it was found that 50% blockage did not affect cerebral blood flow. For the VA100 model, decreased flow in the posterior cerebral artery and a change to the flow direction in the posterior communicating artery were found. For the ICA100 model, particularly, decreased flow in the ipsilateral middle and anterior cerebral arteries and a change to the flow direction in the ipsilateral anterior cerebral artery of the CoW were found. These results demonstrated that the flow system with various CoW disease models tailored to individual characteristics could be used to predict stroke onset more quickly. For the ICA50 and VA100 models, the possibility of cerebral infarction was significantly lower. On the other hand, for the ICA100 model, there was a high possibility of decreased flow, which could lead to cerebral infarction.