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 ◽  
...  

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.

2019 ◽  
Vol 5 (1) ◽  
pp. 533-536
Author(s):  
Lorena Krames ◽  
Rosa Daschner ◽  
Yannick Lutz ◽  
Axel Loewe ◽  
Olaf Dössel ◽  
...  

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.


Stroke ◽  
2012 ◽  
Vol 43 (suppl_1) ◽  
Author(s):  
Ethem Murat Arsava ◽  
Osman Melih Topcuoglu ◽  
Erhan Akpinar ◽  
Kader K Oguz ◽  
Mehmet Akif Topcuoglu

Background: Previous studies have shown reduced penumbral salvage in ischemic stroke patients with higher leukoaraisosis (LA) volume. Although unproven, decreased cerebral vessel density and diminished capacity of cerebral vessels to dilate in response to reduced blood flow in severe LA, are considered among the factors that might explain the association between LA burden and infarct growth in ischemic stroke. Both of these factors, in theory, might negatively affect the extent of collateral blood flow, an important predictor of tissue and clinical outcome in patients with acute ischemic stroke. In this study, we therefore analyzed whether extent of LA adversely affected the degree of collateral circulation in a cohort of patients presenting with middle cerebral artery occlusion. Methods: We retrospectively analyzed a consecutive series of patients admitted with a diagnosis of middle cerebral artery occlusion. Computed tomography angiography source images (CTA-SI) were used to assess the degree of collateral circulation, based on a previously validated scoring system which grades collateral vessels in the sylvian fissure and leptomeningeal convexity separately on a scale from 1 to 5, with 1 being the worst and 5 the best. The extent of LA was determined on FLAIR images by using the Fazekas scale. Multivariate analysis was used to explore the relationship between extent of LA and degree of collateral circulation, adjusted for other covariates like age, gender, vascular risk factors and time from symptom onset to CTA imaging. Results: A total of 51 patients (31 female, 20 male) were included into the study. LA severity was significantly and negatively correlated with the degree of collateral supply (r=-0.31, p=0.03). LA severity (OR 5.9, 95%CI 1.5-24.0) and history of prior stroke (OR 7.8, 95%CI 1.0-59.3) were the only significant variables associated with insufficient collaterals (defined as a combined sylvian and lepotmeningeal collateral score of 5 or less) in the multivariate logistic regression analysis. Conclusion: Patients with higher LA burden have a poor recruitment of collateral vessels after middle cerebral artery occlusion. This association might contribute to reduced penumbral salvage and increased susceptibility to infarct growth observed in patients with severe LA.


2020 ◽  
Vol 38 (4) ◽  
pp. 311-321
Author(s):  
Jiaying Zhu ◽  
Mengmeng Ma ◽  
Jinghuan Fang ◽  
Jiajia Bao ◽  
Shuju Dong ◽  
...  

Background: Statin therapy has been shown to be effective in the prevention of ischemic stroke. In addition, recent studies have suggested that prior statin therapy could lower the initial stroke severity and improve stroke functional outcomes in the event of stroke. It was speculated that prestroke statin use may enhance collateral circulation and result in favorable functional outcomes. Objective: The aim of the study was to investigate the association of prestroke statin use with leptomeningeal collaterals and to determine the association of prestroke statin use with stroke severity and functional outcome in acute ischemic stroke patients. Methods: We prospectively and consecutively enrolled 239 acute ischemic stroke patients with acute infarction due to occlusion of the middle cerebral artery within 24 h in the neurology department of West China Hospital from May 2011 to April 2017. Computed tomographic angiography (CTA) imaging was performed for all patients to detect middle cerebral artery thrombus; regional leptomeningeal collateral score (rLMCS) was used to assess the degree of collateral circulation; the National Institutes of Health Stroke Scale (NIHSS) was used to measure stroke severity at admission; the modified Rankin scale (mRS) was used to measure outcome at 90 days; and premorbid medications were recorded. Univariate and multivariate analyses were performed. Results: Overall, 239 patients met the inclusion criteria. Fifty-four patients used statins, and 185 did not use statins before stroke onset. Prestroke statin use was independently associated with good collateral circulation (rLMCS > 10) (odds ratio [OR], 4.786; 95% confidence interval [CI], 1.195–19.171; P = 0.027). Prestroke statin use was not independently associated with lower stroke severity (NIHSS score≤14) (OR, 1.955; 95% CI, 0.657–5.816; p = 0.228), but prestroke statin use was independently associated with favorable outcome (mRS score≤2) (OR, 3.868; 95% CI, 1.325–11.289; P = 0.013). Conclusions: Our findings suggest that prestroke statin use was associated with good leptomeningeal collaterals and clinical outcomes in acute ischemic stroke (AIS) patients presenting with occlusion of the middle cerebral artery. However, clinical studies should be conducted to verify this claim.


Author(s):  
Karolina Brzegowy ◽  
Bernard Solewski ◽  
Paweł Brzegowy ◽  
Agata Musiał ◽  
Tadeusz Popiela ◽  
...  

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.


1990 ◽  
Vol 259 (2) ◽  
pp. H560-H566 ◽  
Author(s):  
C. M. Loftus ◽  
G. M. Greene ◽  
K. N. Detwiler ◽  
G. L. Baumbach ◽  
D. D. Heistad

Previous studies of intracranial collateral circulation have not distinguished between true "collateral" blood flow (flow to a region that occurs only when a primary artery is occluded) and "overlap" flow (flow to a region that is present under both normal and demand conditions). These experiments had three purposes: 1) to identify tissues that were truly collateral dependent, 2) to determine potential for true collateral flow in the absence of overlap flow, and 3) to determine whether an anatomical basis for overlap flow could be demonstrated. Branches (700-900 microns) of the dog middle cerebral artery (MCA) were perfused with autologous blood. The perfused region, which was the area at risk, was identified by intravenous injection of neutral red dye. Microspheres were used to measure regional cerebral blood flow (rCBF). Overlap flow was determined by perfusion of the artery with microsphere-free blood. True collateral flow (total rCBF minus overlap flow) was determined by analysis of rCBF to the risk area after cessation of vessel perfusion. Most of the risk area had substantial levels of overlap flow (about one-third of base line). In the center of the area at risk, the true collateral-dependent area was identified [mean overlap flow 4 +/- 1 (mean +/- SE) ml.min-1.100 g-1], which had high levels of perfusion from collateral vessels (102 +/- 14) within 30 s of vascular occlusion. Microfil injection into two adjacent MCA branches showed discrete borders between vascular territories, with no overlapping vessels.(ABSTRACT TRUNCATED AT 250 WORDS)


2000 ◽  
Vol 8 (5) ◽  
pp. 1-4 ◽  
Author(s):  
Emanuela Keller ◽  
Thorsten Steiner ◽  
Javier Fandino ◽  
Stefan Schwab ◽  
Werner Hacke

Object Moderate hypothermia has been reported to be effective in the treatment of postischemic brain edema. The effect of hypothermia on cerebral hemodynamics is a matter of controversial discussion in literature. Clinical studies have yet to be performed in patients with ischemic stroke after induction of hypothermia. Methods Measurements during mild hypothermia (33–34°C) were made in six patients with severe ischemic stroke involving the middle cerebral artery territory. Hypothermia was induced as soon as possible and maintained for 48 to 72 hours. Cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRO2) were estimated by a new double-indicator dilution method. Measurements of CBF were made during normothermia, immediately after induction of hypothermia, at the end of hypothermia, and after rewarming. A total of 19 measurements of CBF and jugular bulb O2 saturation were made. Immediately after induction of hypothermia, CBF decreased in all patients. During late hypothermia, CBF improved in patients who survived but remained diminished in the two patients who died. Reduced CMRO2 levels were observed during all phases of hypothermia in all but one case. Conclusions Preliminary oberservations indicate that moderate hypothermia seems to reduce CMRO2 Immediately after induction of hypothermia, CBF may decrease in all patients. During late hypothermia CBF seems to recover in patients with good outcome but remains diminished in patients who die. Serial bedside CBF measurements with the new double-indicator dilution technique may be useful to describe cerebral hemodynamic characteristics in patients with severe ischemic stroke during hypothermia.


1995 ◽  
Vol 15 (6) ◽  
pp. 1075-1081 ◽  
Author(s):  
Michael G. Muhonen ◽  
Christopher M. Loftus ◽  
Donald D. Heistad

Adenosine is a potent cerebral vasodilator. We tested the hypothesis that dilatation of collateral vessels in cerebrum, in response to topical adenosine and 2-chloroadenosine (2-CAD), would increase blood flow to collateral-dependent cerebrum. In dogs anesthetized with halothane, a branch of the middle cerebral artery (MCA) was occluded proximally and cannulated distally. The collateral-dependent area at risk for infarction was perfused from a reservoir with microsphere-free blood, and blood flow to normal cerebrum and to cerebrum dependent on collateral flow was measured with radioactive microspheres injected into the left ventricle through a femoral artery catheter. Perfusion through the cannulated MCA branch was stopped, and flow to normal and collateral-dependent cerebrum was measured after adenosine (10−2 M) or 2-CAD (10−4 M) was added to the superfusate over the cerebrum. In normal cerebrum, topical application of adenosine increased flow to outer but not inner layers. Topical application of adenosine had little effect on flow to collateral-dependent tissue. In normal cerebrum, 2-CAD increased flow to outer layers, whereas flow to inner layers tended to increase. During 2-CAD, flow to outer cortical layers of collateral-dependent cerebrum increased from 140 ± 20 ml/100 g/min (mean ± SD) to 231 ± 68, whereas flow to the inner collateral-dependent tissue did not change. The findings indicate that, after occlusion of a cerebral artery, topical 2-CAD increases blood flow to outer layers of collateral-dependent and normal cerebrum. The findings suggest also that, after arterial occlusion, collateral circulation to cerebrum has dilator reserve, and flow to tissues that are dependent on collaterals may be augmented.


2016 ◽  
Vol 37 (8) ◽  
pp. 3001-3014 ◽  
Author(s):  
Junqiang Ma ◽  
Yonglie Ma ◽  
Bin Dong ◽  
Mischa V Bandet ◽  
Ashfaq Shuaib ◽  
...  

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.


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