Abstract 1122‐000181: Collateral Circulation in Ischemic Stroke is Not Determined by Anatomical Variants of the Cerebral Arteries

2021 ◽  
Vol 1 (S1) ◽  
Author(s):  
Karolina Brzegowy ◽  
Bernard Solewski ◽  
Paweł Brzegowy ◽  
Agata Musiał ◽  
Tadeusz Popiela ◽  
...  
Keyword(s):  
Blood Flow ◽  
Ischemic Stroke ◽  
Collateral Circulation ◽  
Cerebral Arteries ◽  
Anatomical Variations ◽  
Detailed Knowledge ◽  
Collateral Blood Flow ◽  
Posterior Portion ◽  
Cortical Vein ◽  
Anatomical Variants

Introduction : In acute ischemic stroke, collateral circulation determines tissue fate and treatment results. The aim of this study was to evaluate the role of anatomical variations of the Circle of Willis (CoW) in formation of cerebral collateral blood flow in patients with acute M1 occlusion. Methods : This study was a retrospective assessment of radiological examinations of patients with stroke due to middle cerebral artery M1 segment occlusion. All patients underwent mechanical thrombectomy from January 2015 until March 2021. The anatomy of the CoW was assessed on initial CT‐angiography and DSA. CTA was utilized to grade cranial collateral vasculature status and cortical vein opacification score (COVES). Non‐contrast CT scans and ASPECTS scores (using RAPID software) were used to determine the ischemic area. Results : A total of 100 patients were included in the analysis (58 females and 42 males, mean age: 71.6 +/‐ 13.9). We classified the anatomy of the CoW according to its continuity as a full circle. Patients with fully continuous CoW (n = 19) had worse COVES scores than those with CoW incomplete at both anterior and posterior portion (n = 9) (89% vs 68% with COVES 0–2, p = 0.179). No statistically significant results were found when comparing the enhancement of collaterals between these two groups (p = 0.390). The COVES scores were similar for patients with complete and incomplete anterior portions of CoW (77% vs 80% with COVES 0–2, p = 0.812). Patients with incomplete posterior portions of CoW had lower COVES scores than those with complete (80% vs 67% with COVES 0–2, p = 0.206). No statistically significant differences were discovered when comparing different types of the posterior communicating artery (adult, transitional and fetal). Analysis of ischemic areas determined as ASPECTS scores pre‐ and post‐thrombectomy yielded no significant differences between any of the groups. Conclusions : Although certain variants of the CoW have been reported to increase the risk of ischemic stroke, our results show that the anatomy of CoW has no large effect on collateral blood flow during acute M1 occlusion. We presume that the greater role is played by pial arterioles than anatomical variants of major cerebral arteries in cerebral collateral circulation formation. Detailed knowledge about the factors that influence collateral blood flow is crucial as it may aid in identification of patients prone to worse outcomes of ischemic stroke. Anatomical variants of CoW do not play a major role in formation of cerebral collaterals.

scholarly journals Augmenting Collateral Blood Flow during Ischemic Stroke via Transient Aortic Occlusion

2013 ◽  
Vol 34 (1) ◽  
pp. 61-71 ◽  
Author(s):  
Ian R Winship ◽  
Glenn A Armitage ◽  
Gomathi Ramakrishnan ◽  
Bin Dong ◽  
Kathryn G Todd ◽  
...  
Keyword(s):  
Blood Flow ◽  
Ischemic Stroke ◽  
Middle Cerebral Artery ◽  
Cerebral Artery ◽  
Collateral Circulation ◽  
Aortic Occlusion ◽  
Collateral Flow ◽  
Collateral Blood Flow ◽  
Flow Through ◽  
Transient Aortic Occlusion

Collateral circulation provides an alternative route for blood flow to reach ischemic tissue during a stroke. Blood flow through the cerebral collaterals is a critical predictor of clinical prognosis after stroke and response to recanalization, but data on collateral dynamics and collateral therapeutics are lacking. Here, we investigate the efficacy of a novel approach to collateral blood flow augmentation to increase collateral circulation by optically recording blood flow in leptomeningeal collaterals in a clinically relevant model of ischemic stroke. Using high-resolution laser speckle contrast imaging (LSCI) during thromboembolic middle cerebral artery occlusion (MCAo), we demonstrate that transiently diverting blood flow from peripheral circulation towards the brain via intra-aortic catheter and balloon induces persistent increases in blood flow through anastomoses between the anterior and middle cerebral arteries. Increased collateral flow restores blood flow in the distal middle cerebral artery segments to baseline levels during aortic occlusion and persists for over 1 hour after removal of the aortic balloon. Given the importance of collateral circulation in predicting stroke outcome and response to treatment, and the potential of collateral flow augmentation as an adjuvant or stand-alone therapy for acute ischemic stroke, this data provide support for further development and translation of collateral therapeutics including transient aortic occlusion.

scholarly journals Laser Speckle Contrast Imaging of Collateral Blood Flow during Acute Ischemic Stroke

2010 ◽  
Vol 30 (8) ◽  
pp. 1432-1436 ◽  
Author(s):  
Glenn A Armitage ◽  
Kathryn G Todd ◽  
Ashfaq Shuaib ◽  
Ian R Winship
Keyword(s):  
Blood Flow ◽  
Ischemic Stroke ◽  
Cerebral Arteries ◽  
Artery Occlusion ◽  
Laser Speckle ◽  
Collateral Blood Flow ◽  
Contrast Imaging ◽  
Vessel Occlusion ◽  
Laser Speckle Contrast Imaging ◽  
Speckle Contrast

Collateral vasculature may provide an alternative route for blood flow to reach the ischemic tissue and partially maintain oxygen and nutrient support during ischemic stroke. However, much about the dynamics of stroke-induced collateralization remains unknown. In this study, we used laser speckle contrast imaging to map dynamic changes in collateral blood flow after middle cerebral artery occlusion in rats. We identified extensive anastomatic connections between the anterior and middle cerebral arteries that develop after vessel occlusion and persist for 24 hours. Augmenting blood flow through these persistent yet dynamic anastomatic connections may be an important but relatively unexplored avenue in stroke therapy.

Abstract P321: The Cerebral Collateral Cascade: Rethinking the Assessment of Vascular Pathways in Acute Ischemic Stroke Patients

Stroke ◽  
2021 ◽  
Vol 52 (Suppl_1) ◽  
Author(s):  
Tobias D Faizy ◽  
Michael Mlynash ◽  
Reza Kabiri ◽  
Soren Christensen ◽  
Gabriella Kuraitis ◽  
...  
Keyword(s):  
Blood Flow ◽  
Ischemic Stroke ◽  
Acute Ischemic Stroke ◽  
Ct Perfusion ◽  
Infarct Volume ◽  
Strong Predictor ◽  
Secondary Outcome ◽  
Collateral Blood Flow ◽  
Vessel Occlusion ◽  
Cortical Vein

Background and Purpose: Robust collateral blood flow in patients with acute ischemic stroke due to large vessel occlusion (AIS-LVO) has been correlated with favorable outcomes. Collaterals are commonly assessed by the number of arteries present on non-invasive CT angiography (CTA) overlying ischemic brain, but blood transit from these arteries through the brain tissue and the venous drainage is not assessed by this technique. We hypothesized that a comprehensive imaging analysis of the cerebral collateral cascade (CCC) would predict clinical and radiological outcomes in patients with AIS-LVO patients. Materials and Methods: Multicenter retrospective cohort study of AIS-LVO patients undergoing thrombectomy triage. CCC was determined on pre-treatment imaging by scoring for pial arterial collaterals, tissue-level collaterals (TLC), and venous outflow. Pial arterial collaterals were determined by CTA (Tan scale), TLC were assessed on CT perfusion data using the Hypoperfusion Intensity Ratio, and venous egress was assessed on CTA using the cortical vein opacification score system. 3 groups were defined: CCC+ (good pial collaterals, TLC, and venous perfusion), CCC- (poor pial collaterals, TLC, and venous perfusion) and CCCmixed (reminder of patients). Primary outcome was a good functional outcome (modified Rankin Scale [mRS] 0-2 at 90 days). Secondary outcome was final infarct volume. Results: 647 patients met inclusion criteria: 176 CCC+, 345 CCCmixed and 126 CCC-. Multivariate ordinal logistic regression showed that CCC+ predicted good functional outcomes (mRS 0-2: OR=20.8 [95% CI 9.3-46.8]; p<0.001) compared to CCC- and CCCmixed. CCCmixed (β: 27.1, SE: 7.7; p<0.001) and CCC- (β: 86.6, SE: 9.9; p<0.001) profiles were associated with higher final infarct volumes after treatment compared to CCC+. Conclusion: Comprehensive assessment of the collateral blood flow cascade in AIS-LVO patients is a strong predictor of clinical and radiological outcomes in AIS-LVO patients.

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 Effect of Collateral Blood Flow on Patients Undergoing Endovascular Therapy for Acute Ischemic Stroke

Stroke ◽  
2014 ◽  
Vol 45 (4) ◽  
pp. 1035-1039 ◽  
Author(s):  
Michael P. Marks ◽  
Maarten G. Lansberg ◽  
Michael Mlynash ◽  
Jean-Marc Olivot ◽  
Matus Straka ◽  
...  
Keyword(s):  
Blood Flow ◽  
Ischemic Stroke ◽  
Acute Ischemic Stroke ◽  
Endovascular Therapy ◽  
Collateral Blood Flow

scholarly journals Analysis of Thrombi Retrieved from Cerebral Arteries of Patients with Acute Ischemic Stroke.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 263-263
Author(s):  
Victor J. Marder ◽  
Dennis J. Chute ◽  
Sidney Starkman ◽  
Anna M. Abolian ◽  
Chelsea Kidwell ◽  
...  
Keyword(s):  
Blood Flow ◽  
Ischemic Stroke ◽  
Carotid Artery ◽  
Middle Cerebral Artery ◽  
Acute Ischemic Stroke ◽  
Cerebral Artery ◽  
Cerebral Arteries ◽  
Clinical Consequence ◽  
Initiation Of Therapy ◽  
Stroke Center

Abstract To obtain insights into the pathogenesis of ischemic stroke, we analyzed thromboemboli and other occlusive material retrieved acutely from the cerebral arteries of patients. The experimental design was an observational study in 25 consecutive patients with acute ischemic stroke treated by endovascular mechanical thromboembolectomy. Patients with acute occlusion of a proximal cerebral artery, a disabling neurologic deficit, and either initiation of therapy within 8 hours of onset or initiation of therapy beyond 8 hours if imaging demonstrated substantial residual penumbral tissue at risk were treated at a tertiary Comprehensive Stroke Center (the UCLA Stroke Center). Thrombus was removed by an endovascular mechanical embolectomy device (Merci® Retriever System, Concentric Medical, Mountain View, CA) after placement by angiographic catheter into the occluded intracranial carotid artery, middle cerebral artery or vertebral-basilar artery under fluoroscopic guidance. Our results show that the large majority (20 of 25) of extracted thrombi have similar histologic architecture, a complex of layered, sometimes serpentine, lengths of fibrin:platelet deposits interspersed with linear streaks of nucleated cells. This histology was prevalent with both cardioembolic and atherosclerotic etiologies, indicating the same pathogenetic influences of blood flow and shear in thrombus formation. This histologic pattern among thrombi was present in both the internal carotid artery (ICA) and the middle cerebral artery (MCA). Clots composed uniformly of erythrocytes were uncommon (3 of 25) and were observed only with incomplete extractions, suggesting that sampling was of the proximal thrombus tail where post-occlusion thrombosis had occurred under conditions of stagnant flow. Calcifications or cholesterol were not present. Thrombus size, not histology, predicted the site of arterial occlusion, with no thrombus larger than 3 mm width causing stroke limited to the MCA and no thrombus larger than 5 mm width removed from the ICA. Fungus-containing thrombus was extracted from one patient who had mycotic valvular disease, and an unusual complication occurred in another case, namely, scraping of a small atheroma and attached intima from the MCA, albeit without clinical consequence. We conclude that thromboemboli that cause acute ischemic stroke are of similar, complex structure, regardless of macroscopic dimensions, and are similarly influenced by blood flow, whether the primary etiology is cardioembolic or atherosclerotic. Embolus size is the critical aspect that determines its ultimate destination, those of more than 5 mm width appearing to bypass the cerebral vessels entirely. The mixed fibrin:platelet pattern present in the preponderance of thromboemboli provides foundation for the success of both antiplatelet and anticoagulant treatment strategies in stroke prevention.

An Experimental Study of the Effects Anatomical Variations Have on Collateral Flows Within the Circle of Willis

2011 ◽  
Author(s):  
Paul Fahy ◽  
Patrick Delassus ◽  
Padraig O’Flynn ◽  
Liam Morris
Keyword(s):  
Experimental Study ◽  
Blood Flow ◽  
Cerebral Arteries ◽  
Anatomical Variations ◽  
Flow Patterns ◽  
Circle Of Willis ◽  
Collateral Flow ◽  
Arterial Network ◽  
Flow Feature ◽  
The Brain

The circle of Willis (CoW) is a complex arterial network comprising of major cerebral arteries that converge to form a pentagonal arrangement as shown in Figure 1(A). This arterial network supplies oxygen-enriched blood to the brain. An incomplete CoW can exist in up to 50% of cases [1]. These missing vessels can be accommodated by the collateral flow feature within the CoW configuration. In certain circumstances, anatomical variations within the CoW can result in undesirable flow patterns [2–3]. It is unclear from the literature what effects these variations can have on blood flow collision paths within a complete CoW.

scholarly journals Strategies of Collateral Blood Flow Assessment in Ischemic Stroke: Prediction of the Follow-Up Infarct Volume in Conventional and Dynamic CTA

2014 ◽  
Vol 36 (3) ◽  
pp. 488-494 ◽  
Author(s):  
S.E. Beyer ◽  
K.M. Thierfelder ◽  
L. von Baumgarten ◽  
M. Rottenkolber ◽  
F.G. Meinel ◽  
...  
Keyword(s):  
Blood Flow ◽  
Ischemic Stroke ◽  
Infarct Volume ◽  
Collateral Blood Flow

scholarly journals Predictive Value of CT Perfusion Imaging on the Basis of Automatic Segmentation Algorithm to Evaluate the Collateral Blood Flow Status on the Outcome of Reperfusion Therapy for Ischemic Stroke

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Qingsong Gong ◽  
Botao Yu ◽  
Mengjie Wang ◽  
Min Chen ◽  
Haowen Xu ◽  
...  
Keyword(s):  
Blood Flow ◽  
Ischemic Stroke ◽  
Perfusion Imaging ◽  
Ct Perfusion ◽  
Automatic Segmentation ◽  
Reperfusion Therapy ◽  
Segmentation Algorithm ◽  
Collateral Flow ◽  
Collateral Blood Flow ◽  
Ct Perfusion Imaging

Our objective was to study the predictive value of CT perfusion imaging based on automatic segmentation algorithm for evaluating collateral blood flow status in the outcome of reperfusion therapy for ischemic stroke. All data of 30 patients with ischemic stroke reperfusion in our hospital were collected and examined by CT perfusion imaging. Convolutional neural network (CNN) algorithm was used to segment perfusion imaging map and evaluate the results. The patients were grouped by regional leptomeningeal collateral score (rLMCs). Binary logistic regression was used to analyze the independent influencing factors of collateral blood flow on brain CT perfusion. The modified Scandinavian Stroke Scale was used to evaluate the prognosis of patients, and the effects of different collateral flow conditions on prognosis were obtained. The accuracy of CNN segmentation image is 62.61%, the sensitivity is 87.42%, the similarity coefficient is 93.76%, and the segmentation result quality is higher. Blood glucose (95% CI = 0.943, P = 0.028 ) and ischemic stroke history (95% CI = 0.855, P = 0.003 ) were independent factors affecting the collateral blood flow status of stroke patients. CBF (95% CI = 0.818, P = 0.008 ) and CBV (95% CI = 0.796, P = 0.016 ) were independent influencing factors of CT perfusion parameters. After 3 weeks of onset, the prognostic function defect score of the good collateral flow group (11.11%) was lower than that of the poor group (41.67%) ( P < 0.05 ). The automatic segmentation algorithm has more accurate segmentation ability for stroke CT perfusion imaging and plays a good auxiliary role in the diagnosis of clinical stroke reperfusion therapy. The collateral blood flow state based on CT perfusion imaging is helpful to predict the treatment outcome of patients with ischemic stroke and further predict the prognosis of patients.

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