scholarly journals The impact of native leptomeningeal collateralization on rapid blood flow recruitment following ischemic stroke

2020 ◽  
Vol 40 (11) ◽  
pp. 2165-2178
Author(s):  
Atsushi Kanoke ◽  
Yosuke Akamatsu ◽  
Yasuo Nishijima ◽  
Eric To ◽  
Chih C Lee ◽  
...  
Keyword(s):  
Blood Flow ◽  
Ischemic Stroke ◽  
Independent Predictor ◽  
Mouse Strains ◽  
Collateral Flow ◽  
Stroke Outcome ◽  
Slight Improvement ◽  
Cortical Stroke ◽  
The Impact ◽  
Cortical Perfusion

The leptomeningeal collateral status is an independent predictor of stroke outcome. By means of optical coherent tomography angiography to compare two mouse strains with different extent of native leptomeningeal collateralization, we determined the spatiotemporal dynamics of collateral flow and downstream hemodynamics following ischemic stroke. A robust recruitment of leptomeningeal collateral flow was detected immediately after middle cerebral artery (MCA) occlusion in C57BL/6 mice, with continued expansion over the course of seven days. In contrast, little collateral recruitment was seen in Balb/C mice during- and one day after MCAO, which coincided with a greater infarct size and worse functional outcome compared to C57BL/6, despite a slight improvement of cortical perfusion seven days after MCAO. Both strains of mice experienced a reduction of blood flow in the penetrating arterioles (PA) by more than 90% 30-min after dMCAO, although the decrease of PA flow was greater and the recovery was less in the Balb/C mice. Further, Balb/C mice also displayed a prolonged greater heterogeneity of capillary transit time after dMCAO in the MCA territory compared to C57BL/6 mice. Our data suggest that the extent of native leptomeningeal collaterals affects downstream hemodynamics with a long lasting impact in the microvascular bed after cortical stroke.

Abstract 61: MR Perfusion to Determine the Status of Collaterals in Patients With Acute Ischemic Stroke: Look Beyond Perfusion Time-maps

Stroke ◽  
2016 ◽  
Vol 47 (suppl_1) ◽  
Author(s):  
Kambiz Nael ◽  
James Knitter ◽  
Amish Doshi ◽  
J Mocco ◽  
Thomas Naidich
Keyword(s):  
Ischemic Stroke ◽  
Diagnostic Accuracy ◽  
Cerebral Angiography ◽  
Independent Predictor ◽  
Collateral Flow ◽  
Mr Perfusion ◽  
The Status ◽  
Perfusion Time ◽  
Sensitivity Specificity ◽  
Angiographic Findings

Purpose: Collateral flow is an independent predictor of reperfusion and infarct size in patients with acute ischemic stroke (AIS). MR perfusion time-maps show delayed perfusion but unable to differentiate antegrade from collateral flow if used alone. Using a multiparametric approach, we aimed to identify a perfusion biomarker that can represent the extent of collaterals in comparison to angiographic findings. Methods: AIS patients with MCA proximal occlusion who had baseline MRI and cerebral angiography included. MR perfusion data were processed by Bayesian method to generate arterial tissue delay (ATD) maps at thresholds of 2 & 6 seconds. The volume of delayed perfusion (Vol-ATD 2sec ), critical hypoperfusion (Vol-ATD 6sec ), and hypoperfusion (Vol-ATD 2sec-6sec ) in addition to corresponding rCBV and rCBF were calculated. Baseline angiography collaterals were dichotomized to poor (TICI ≤2a) or good collaterals (TICI≥ 2b). The association of perfusion biomarkers and status of collaterals was assessed by repeated measure of analyses and receiver operating characteristic (ROC) to determine the optimal parameters for predicting the status of collaterals. Results: In 37 patients included, 20 had good collaterals on cerebral angiography. After controlling for age, baseline NIHSS and infarct volume, multivariate logistic regression analysis identified rCBV (p=0.001) and hypoperfused volume (Vol-ATD 2sec-6sec ), but not rCBF, Vol-ATD 2sec or Vol-ATD 6sec , as independent predictors of good collaterals. ROC analysis showed AUC of 0.89 (sensitivity/specificity: 85%90%) for rCBV and AUC of 0.78 (sensitivity/specificity: 70%82%) for Vol-ATD 2sec-6sec . Hypoperfused tissue volume (Vol-ATD 2sec-6sec ) x its rCBV, termed hypoperfused tissue collateral index , remained an independent predictor of good collaterals with improved diagnostic accuracy over each measure alone (AUC: 0.96, sensitivity/specificity: 91%100%). Conclusions: Multiparametric MR perfusion can be used to assess the status of collaterals in patients with AIS. Hypoperfused tissue collateral index defined as hypoperfused volume (Vol-ATD 2sec-6sec ) x rCBV is a new perfusion index with diagnostic accuracy of 96% compared to angiographic findings to predict status of collaterals.

scholarly journals The impact of leptomeningeal collaterals in acute ischemic stroke

2020 ◽  
Author(s):  
Nida Fatima ◽  
Maher Saqqur ◽  
Ashfaq Shuaib
Keyword(s):  
Blood Flow ◽  
Ischemic Stroke ◽  
Clinical Outcome ◽  
Acute Ischemic Stroke ◽  
Meta Analysis ◽  
Random Effect ◽  
Random Effect Model ◽  
Mesh Terms ◽  
Favorable Clinical Outcome ◽  
The Impact

Abstract Objectives: Leptomeningeal collaterals provide an alternate pathway to maintain cerebral blood flow in stroke to prevent ischemia, but their role in predicting outcome is still unclear. So, our study aims at assessing the significance of collateral blood flow (CBF) in acute stroke. Methods: Electronic databases were searched under different MeSH terms from Jan 2000 to Feb 2019. Studies were included if there was available data on good and poor CBF in acute ischemic stroke (AIS). The clinical outcomes included were modified rankin scale (mRS), recanalization, mortality, and symptomatic intracranial hemorrhage (sICH) at 90 days. Data was analyzed using random-effect model.Results: A total of 47 studies with 8,194 patients were included. Pooled meta-analysis revealed that there exist 2-fold higher likelihood of favorable clinical outcome (mRS≤2) at 90 days with good CBF compared with poor CBF (RR: 2.27; 95%CI: 1.94-2.65; p<0.00001) irrespective of the thrombolytic therapy [RR with IVT: 2.90; 95%CI: 2.14-3.94; p<0.00001, and RR with IAT/EVT: 1.99; 95% CI: 1.55-2.55; p<0.00001]. Moreover, there exists 1-fold higher probability of successful recanalization with good CBF (RR: 1.31; 95% CI: 1.15-1.49; p<0.00001). However, there was 54% and 64% lower risk of sICH and mortality respectively in patients with good CBF in AIS (p<0.00001).Conclusions: The relative risk of favorable clinical outcome is more in patients with good pretreatment CBF. This could be explained due to better chances of recanalization, combined with lesser risk of intracerebral hemorrhage in good CBF status.

scholarly journals The impact of recanalization on ischemic stroke outcome: A clinical case presentation

2012 ◽  
Vol 1 (1-12) ◽  
pp. 455-458 ◽  
Author(s):  
Silva Andonova ◽  
Filip Kirov ◽  
Chavdar Bachvarov
Keyword(s):  
Ischemic Stroke ◽  
Clinical Case ◽  
Stroke Outcome ◽  
Case Presentation ◽  
The Impact

Abstract T P83: Strain Differences In Leptomeningeal Collateral Flow Dynamics Correlate With Differences In Stroke Outcome

Stroke ◽  
2015 ◽  
Vol 46 (suppl_1) ◽  
Author(s):  
Yasuo Nishijima ◽  
Yosuke Akamtsu ◽  
Chih Cheng Lee ◽  
Jialing Liu
Keyword(s):  
Blood Flow ◽  
Acute Phase ◽  
Collateral Circulation ◽  
Artery Occlusion ◽  
Flow Dynamics ◽  
Mouse Strains ◽  
Collateral Flow ◽  
Doppler Flowmetry ◽  
Collateral Arteries ◽  
Retrograde Filling

Introduction: Emerging evidences suggest that the collateral circulation plays a key role in the risk of stroke and the severity of infarction. The current study aimed to investigate the effect of the brain collateral circulation in acute phase of stroke and outcome in two inbred mouse strains that differ markedly in anatomical collateralization. Methods: Male C57BL/6 and Balb/C mice were subjected to permanent unilateral common carotid artery occlusion (CCAO) or temporary distal middle cerebral artery occlusion (dMCAo). Regional cerebral blood flow (rCBF) was assessed by laser doppler flowmetry. In vivo imaging of collateral blood flow and flow velocity was evaluated by doppler optical coherence tomography (DOCT). Infarct size and motor function was assessed at 24 hours and 1 week after dMCAo, respectively. DiI-labeling was used to reveal anastomoses and to determine vessel diameter. Results: The diameters of the ICA and ACA on the ischemic side in both strains markedly decreased at 24 hours after CCAO but recovered at 7 days, although the diameters of ICA, MCA and ACA are larger in the Balb/C compared to the C57BL/6 strain before and after CCAO. Balb/C mice exhibited significantly less leptomeningeal connecting collateral arteries compared to C57BL/6 (0.6±0.3 vs 11.3±0.4, p<0.001), coincided with a larger infarction and worse neurological outcomes after dMCAo compared to C57BL/6. During the acute phase of occlusion of the CCA or MCA, C57BL/6 mice also demonstrated a much more robust retrograde filling of several distal branches of the MCA from ACA compared to Balb/C mice. Conclusion: Our results demonstrate that anatomical insufficiency of the leptomeningeal collateralization is associated with an impaired collateral flow dynamics, resulting in reduced rCBF during the acute phase of MCA stroke, which might in part, contribute to the larger infarction observed in the Balb/C strain.

scholarly journals Modeling of the Human Cerebral Collateral Circulation: Evaluation of the Impact on the Cerebral Perfusion in Case of Ischemic Stroke

2019 ◽  
Vol 5 (1) ◽  
pp. 533-536
Author(s):  
Lorena Krames ◽  
Rosa Daschner ◽  
Yannick Lutz ◽  
Axel Loewe ◽  
Olaf Dössel ◽  
...  
Keyword(s):  
Blood Flow ◽  
Ischemic Stroke ◽  
Middle Cerebral Artery ◽  
Cerebral Artery ◽  
Collateral Circulation ◽  
Treatment Method ◽  
Developed Countries ◽  
Extended Model ◽  
Flow Through ◽  
The Impact

AbstractStroke is the third-most cause of death in developed countries. A new promising treatment method in case of an ischemic stroke is selective intracarotid blood cooling combined with mechanical artery recanalization. However, the control of the treatment requires invasive or MRI-assisted measurement of cerebral temperature. An auspicious alternative is the use of computational modeling. In this work, we extended an existing 1D hemodynamics model including the characteristics of the anterior, middle and posterior cerebral artery. Furthermore, seven ipsilateral anastomoses were additionally integrated for each hemisphere. A potential stenosis was placed into the M1 segment of the middle cerebral artery, due to the highest risk of occlusion there. The extended model was evaluated for various degrees of collateralization (“poor”, “partial” and “good”) and degrees of stenosis (0%, 50%, 75% and 99.9%). Moreover, cerebral autoregulation was considered in the model. The higher the degree of collateralization and the degree of stenosis, the higher was the blood flow through the collaterals. Hence, a patient with a good collateralization could compensate a higher degree of occlusion and potentially has a better outcome after an ischemic stroke. For a 99.9% stenosis, an increased summed mean blood flow through the collaterals of +97.7% was predicted in case of good collateralization. Consequently, the blood supply via the terminal branches of the middle cerebral artery could be compensated up to 44.4% to the physiological blood flow. In combination with a temperature model, our model of the cerebral collateral circulation can be used for tailored temperature prediction for patients to be treated with selective therapeutic hypothermia.

scholarly journals Prevention of the collapse of pial collaterals by remote ischemic perconditioning during acute ischemic stroke

2016 ◽  
Vol 37 (8) ◽  
pp. 3001-3014 ◽  
Author(s):  
Junqiang Ma ◽  
Yonglie Ma ◽  
Bin Dong ◽  
Mischa V Bandet ◽  
Ashfaq Shuaib ◽  
...  
Keyword(s):  
Blood Flow ◽  
Ischemic Stroke ◽  
Acute Ischemic Stroke ◽  
Cerebral Artery ◽  
Laser Speckle ◽  
Laser Scanning Microscopy ◽  
Collateral Flow ◽  
Contrast Imaging ◽  
Peripheral Ischemia ◽  
Remote Ischemic Perconditioning

Collateral circulation is a key variable determining prognosis and response to recanalization therapy during acute ischemic stroke. Remote ischemic perconditioning (RIPerC) involves inducing peripheral ischemia (typically in the limbs) during stroke and may reduce perfusion deficits and brain damage due to cerebral ischemia. In this study, we directly investigated pial collateral flow augmentation due to RIPerC during distal middle cerebral artery occlusion (MCAo) in rats. Blood flow through pial collaterals between the anterior cerebral artery (ACA) and the MCA was assessed in male Sprague Dawley rats using in vivo laser speckle contrast imaging (LSCI) and two photon laser scanning microscopy (TPLSM) during distal MCAo. LSCI and TPLSM revealed that RIPerC augmented collateral flow into distal MCA segments. Notably, while control rats exhibited an initial dilation followed by a progressive narrowing of pial arterioles 60 to 150-min post-MCAo (constricting to 80–90% of post-MCAo peak diameter), this constriction was prevented or reversed by RIPerC (such that vessel diameters increased to 105–110% of post-MCAo, pre-RIPerC diameter). RIPerC significantly reduced early ischemic damage measured 6 h after stroke onset. Thus, prevention of collateral collapse via RIPerC is neuroprotective and may facilitate other protective or recanalization therapies by improving blood flow in penumbral tissue.

EARLY PREDICTION OF ACUTE ISCHEMIC STROKE OUTCOME BY USING ALBERTA STROKE PROGRAM EARLY CT SCORE (ASPECTS)

2014 ◽  
pp. 168-176
Author(s):  
Vu Xuan Loc Doan ◽  
Thanh Thao Nguyen ◽  
Minh Loi Hoang ◽  
Trong Hao Vo
Keyword(s):  
Computed Tomography ◽  
Ischemic Stroke ◽  
Clinical Outcome ◽  
Acute Ischemic Stroke ◽  
Independent Predictor ◽  
Univariate Analysis ◽  
Early Prediction ◽  
Stroke Outcome ◽  
Good Outcome ◽  
Poor Outcome

Background and Purpose: The Alberta Stroke Program Early CT Score (ASPECTS) scale semiquantitatively assesses extent and location of ischemic changes within the middle cerebral artery (MCA) territory using a 10-point grading system. ASPECTS measured at baseline using noncontrast computed tomography (CT) scan. The aim of this study was to assess early prediction of clinical outcome after acute ischemic stroke by ASPECTS scale. Methods: The study based on convenience sample which included 82 first-ever acute ischemic stroke patients, admitted to Hue Central Hospital within 72 hours of stroke onset, from October 2013 to October 2014. Ischemic territory changes were defined as parenchymal CT hypoattenuation. We assessed all baseline CT scans, dichotomized ASPECTS at ≤ 7 and >7, defined good outcome (0 to 2) and poor outcome (3 to 6) as modified Rankin Scale (mRS) score at discharge. Univariate analysis and multivariable logistic regression analysis were performed to define the independent predictors for stroke outcome. Results: Mean age was 68.35 ± 13.93 years, proportion of male (51.2%) and female (48.8%) are approximately the same. ASPECTS score > 7 in 57 patients and ≤ 7 in 25 patients. Mean ASPECTS was 7.51 ± 2.25. Mean mRS at discharge was 2.28 ± 1.33. Good outcome (mRS ≤ 2) and poor outcome (mRS > 2) at discharge were 63.4% and 36.6% respectively. There is a negative correlation between ASPECTS and mRS (r = -0.86, p < 0.001). In the univariate analysis, atrial fibrillation, Glasgow Coma Scale (GCS) score at admisison, ASPECT score and infarct volume were significantly associated with stroke outcome. All of aforementioned variables underwent multivariate analysis, but none of them was proven to be an independent predictor of early outcome. Conclusion: In patients with first-ever acute ischemic stroke, ASPECT score which bases on conventional computed tomography scan is not independent predictor for clinical outcome at discharge. Key words: ischemic stroke, ASPECTS, outcome

Abstract 11: Assessing the True ImpACT-24B: Magnitude of Benefit of Sphenopalatine Ganglion Stimulation for Acute Ischemic Stroke with Confirmed Cortical Involvement

Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Fausto E Ordonez ◽  
David Liebeskind ◽  
Mersedeh Bahr ◽  
Ashfaq Shuaib Shuaib ◽  
Natan Bornstein ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Acute Ischemic Stroke ◽  
Absolute Risk ◽  
Number Needed To Treat ◽  
Collateral Flow ◽  
Sphenopalatine Ganglion ◽  
Stroke Patients ◽  
Sham Stimulation ◽  
Cortical Involvement ◽  
The Impact

Background: Sphenopalatine ganglion (SPG) stimulation enhances collateral flow, stabilizes blood-brain barrier, and showed evidence of benefit in patients with confirmed cortical involvement (CCI) when started 8-24h after onset in the ImpACT-24B randomized trial. To characterize SPG stimulation benefit magnitude, we derived number needed to treat (NNT) values based on shifts over all levels of 3 month global disability. Methods: From the distribution of the 7-level modified Rankin Scale (mRS) at 3m in SPG- and sham-stimulation CCI patients, NNT to benefit (NNTB) and NNT to harm (NNTH) values were derived by automated (algorithmic min-max) and expert generation of joint outcome distribution tables. For dichotomized mRS outcomes, net NNT values were derived directly from absolute risk differences. Results: Among 520 patients with confirmed cortical infarction ineligible for thrombolysis, 244 were treated with SPG and 276 with sham stimulation. NNT values for dichotomized and shift mRS outcomes are shown in the Table. Of the 6 possible binary cutpoints on the mRS, 4 showed more favorable outcome with SPG stimulation. The dichotomized endpoint with the greatest group difference was ambulatory and capable of bodily self-care (mRS 0-3), 62.3% vs 51.1%, NNTB 8.9. Across all 6 individual possible dichotomizations of the mRS, the NNTB ranged from 8.9 to -166.7. For shifts by 1 or more levels across all 6 transitions of the mRS, the biologically most plausible NNTB was 5.7 (IQR 5.6-6.5), NNTH 34.5 (IQR 30.3-40.0), and net NNTB 6.8 (IQR 6.5-7.7), These values correlated closely with the automatically derived net NNTB of 5.9. Conclusions: The findings of this pivotal trial indicate that, out of every 1000 CCI patients treated with SPG stimulation, 146 patients will have a less disabled 3-month outcome, including 76 more who will be functionally independent. SPG stimulation can substantially improve the outcome of thrombolysis-ineligible acute ischemic stroke patients.

scholarly journals Analyzing Circle of Willis blood flow in ischemic stroke patients through 3D Stroke Arterial Flow Estimation

2017 ◽  
Vol 23 (4) ◽  
pp. 427-432 ◽  
Author(s):  
Aichi Chien ◽  
Fernando Viñuela
Keyword(s):  
Blood Flow ◽  
Ischemic Stroke ◽  
Flow Patterns ◽  
Circle Of Willis ◽  
Arterial Flow ◽  
Patient Specific ◽  
Collateral Flow ◽  
Flow Data ◽  
Time Resolved ◽  
Flow Estimation

Background The objective of ischemic stroke (IS) treatment is to achieve revascularization in cerebral arteries to restore blood flow. However, there is no available method to extract arterial flow data from clinical CTA images. We developed 3D Stroke Arterial Flow Estimation (SAFE), which provides blood flow data throughout the Circle of Willis based on 3D CTA and allows comparison of arterial flow distribution in the brain. Methods We implemented a newly developed 3D vascular reconstruction algorithm for clinical stroke CTA images. Based on the patient-specific vascular structure, SAFE calculates time-resolved blood flow information for the entire Circle of Willis and allows quantitative flow study of IS cases. Clinical IS cases are presented to demonstrate the feasibility. Four patients with CTA images and CT perfusion data were studied. To validate the SAFE analysis, correlation analysis comparing blood flow at the MCA, ICA, and BA was performed. Results Different blood flow patterns were found in individual IS patients. Altered flow patterns and high collateral flow rates were found near occlusions in all cases. Quantitative comparison of blood flow data showed that SAFE obtained flow data and CTP were significantly correlated and provide complementary information about cerebral blood flow for individual patients. Conclusions We present SAFE analysis for collecting detailed time-resolved cerebral arterial flow data in the entire Circle of Willis for IS. Further study with more cases may be important to test the clinical utilization of SAFE and helpful to the study of the underlying hemodynamics of stroke.

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