Revascularization For Acute Ischemic Stroke Research Articles

Abstract TMP56: Accuracy of Dual-Energy Computed Tomography for Differentiation Between Cerebral Hemorrhage and Contrast Extravasation Following Mechanical Revascularization in Acute Ischemic Stroke: A Diagnostic Accuracy Meta-Analysis

Background: Mechanical revascularization has become an essential treatment for acute ischemic stroke patients. Post-treatment imaging frequently displays hyperdense regions, prompting concerns regarding possible cerebral hemorrhage. Dual-energy computed tomography (DECT), as an advanced imaging modality, offers the potential to discern between hemorrhage and harmless contrast leakage. Aim: This study aims to assess the diagnostic precision of DECT in distinguishing cerebral hemorrhage from contrast extravasation post-mechanical revascularization in acute ischemic stroke cases. Methods: A comprehensive search was performed for PubMed, EMBASE, and the Cochrane Library until January 2023. We focused on studies that focused on the diagnostic efficacy of DECT for this specific application. R software (version 4.0.3) coupled with mada package facilitated the analyses pooling metrics such as sensitivity, specificity, false-positive rate estimates, diagnostic odds ratio, and positive and negative Likelihood Ratios. These metrics were reported with a 95% Confidence Interval (CI). Results: Our analysis included 5 studies involving 241 patients. DECT demonstrated a pooled sensitivity of 94.5% (95% CI: 25.9% to 99.9%, I 2 =0%) and a specificity of 99% (95% CI: 77.3% to 100%, I 2 =0%). The false-positive rate was minimal at 1% (95% CI: 0% to 22.7%). The positive likelihood ratio was calculated as 98.94 (95% CI: 3.34 to 2929.22), while the negative likelihood ratio was 0.05 (95% CI: 0.001 to 2.21). The diagnostic odds ratio was substantial at 1795.17 (95% CI: 10.04 to 321055.24), signifying a robust performance of DECT in making the differentiation. Conclusion: While DECT manifests impressive accuracy in differentiating cerebral hemorrhage from contrast extravasation after mechanical revascularization in acute ischemic stroke cases, the wide confidence intervals signify a degree of uncertainty in these estimates. Nevertheless, given its high diagnostic metrics, DECT can substantially influence post-intervention evaluations, paving the way for more informed clinical decisions and potentially reducing patient adverse outcomes. However, further studies with larger sample sizes might help refine these diagnostic estimates.

Update on Large-Vessel Revascularization in Acute Ischemic Stroke

Update on Large-Vessel Revascularization in Acute Ischemic Stroke

Abstract WP117: Post-procedural Screening With ROTEM For Risk Of Hemorrhage Following Revascularization Therapy For Acute Ischemic Stroke

Introduction: Hyperfibrinolysis is associated with intracerebral hemorrhage (ICH) after the use of tPA for acute ischemic stroke (AIS). Point-of-care Rotational ThromboElastoMetry (ROTEM) testing may rapidly detect hyperfibrinolysis and identify AIS patients at high risk for hemorrhage. Hypothesis: Evidence of fibrinogen depletion on ROTEM will accurately predict bleeding following revascularization therapy for AIS. Methods: We reviewed medical records of AIS patients who underwent revascularization therapy between 2019-2020. All patients underwent ROTEM testing post-procedure to facilitate targeted blood product transfusion should hemorrhage occur. However, transfusion was not performed prophylactically. Repeat imaging with dual-energy CT was performed within 24 hours. A quality control registry of all AIS patients who undergo revascularization is maintained for purposes of Joint Commission certification. All variables, including ROTEM values and occurrence of intra- and extracranial hemorrhage, were entered prospectively. We examined the predictive value of a FIBTEM-A10 <10mm for post-procedural hemorrhage. Results: A total of 52 patients were included. Median age was 68 years (Interquartile Range, IQR 60-83), and median admission NIHSS was 16 (IQR 10-20). Thirty-four patients (65%) received tPA, 46 (88%) received mechanical thrombectomy, and 28 (54%) received both. Median post-procedure FIBTEM-A10 was 16mm (IQR 14-22); 5 patients had values <10mm. Overall, 19 (37%) suffered radiographic ICH, 5 (10%) symptomatic ICH, and 3 (6%) extracranial hemorrhage. FIBTEM-A10 <10mm had sensitivity 17% and specificity 97% for any post-procedural hemorrhage. For symptomatic ICH, sensitivity was 0% and specificity 89%. Conclusions: The use of ROTEM to identify hyperfibrinolysis following AIS revascularization therapy achieved poor sensitivity and high specificity for prediction of any post-procedural hemorrhage, but was inaccurate for the prediction of symptomatic ICH.

A feasible alternative to transfemoral artery access for endovascular revascularization in acute ischemic stroke in cases with difficult vessel anatomy

Endovascular treatment in acute ischemic stroke is usually performed via a transfemoral approach. Catheterization can be problematic in cases with difficult anatomy: unfavorable arch type, vessel tortuosity and ostial stenosis, aorta coarc‑ tation, iliac artery occlusion. The aim of this review is to describe the place of another arterial approach in the manage‑ ment in acute ischemic stroke: direct common carotid

Transcranial Doppler 6 h after Successful Reperfusion as a Predictor of Infarct Volume

ObjectivesThe aim of the study is to analyze the hemodynamic changes in the middle cerebral artery (MCA) after endovascular revascularization in acute ischemic stroke (AIS) due to large vessel occlusion and its association with the infarct volume size in the control head CT. Materials and MethodsProspective study of patients with AIS due to internal carotid artery terminus or M1 segment of the MCA occlusion, who underwent endovascular treatment with a final TICI 2b-3 score, without concomitant stenosis ≥50% in both cervical carotid arteries. Transcranial Doppler ultrasound (TCD) of both MCAs was carried out at 6 h after the endovascular procedure. Mean flow velocities (MFV) after arterial reperfusion and its association with the infarct volume size in 24−36 h control head CT were determined. Results91 patients (51 women) were included with a median age of 78 years and National institute of Health Stroke Scale of 18. The MCA was occluded in 76.92%, and intravenous thrombolysis was administered in 40.7%. The incidence of symptomatic intracranial hemorrhage was 5.5%. At three months, mortality was 19.8% and a 52.7% of patients achieved functional independence (modified Rankin Scale 0-2). After a multivariable logistic regression analysis, an increase in the MFV greater than 50% at 6 h in the treated MCA compared to contralateral MCA, was an independent predictor of large infarct volume in the control head CT with an OR 9.615 (95%CI: 1.908−47.620), p=0.006 ConclusionsIncreased MFV assessed by TCD examination following endovascular recanalization is independently associated with larger infarct volume

Types of intraparenchymal hematoma as a predictor after revascularization in patients with anterior circulation acute ischemic stroke.

Background: Intracranial hemorrhage after revascularization for acute ischemic stroke is associated with poor outcomes. Few reports have examined the relationship between parenchymal hematoma after revascularization and clinical outcomes. This retrospective study aimed to investigate the risk factors and clinical outcomes of parenchymal hematoma after revascularization for acute ischemic stroke.Methods: Ninety-three patients underwent revascularization for anterior circulation acute ischemic stroke. Patient characteristics and clinical outcomes were compared between patients with and without post procedural parenchymal hematoma using the following parameters: age, sex, occlusion location, presence of atrial fibrillation, diffusion-weighted imaging-Alberta stroke program early computed tomography score (DWI-ASPECTS), National Institute of Health Stroke Scale (NIHSS) score, recombinant tissue plasminogen activator, thrombolysis in cerebral infarction > 2b, door-to-puncture time, onset-to-recanalization time, number of passes, and modified Rankin Scale scores.Results: Parenchymal hematomas were not significantly correlated with age, sex, occlusion location, atrial fibrillation, DWI-ASPECTS, NIHSS score, recombinant tissue plasminogen activator, thrombolysis in cerebral infarction > 2b, door-to-puncture time, onset-to-recanalization time, and number of passes, but were significantly correlated with poor clinical outcomes (P = 0.001) and absence of the anterior communicating artery evaluated using pre procedural time-of-flight magnetic resonance angiography (P = 0.03).Conclusion: Parenchymal hematoma was a predictor of poor outcomes. In particular, the absence of the anterior communicating artery on pre procedural time-of-flight magnetic resonance angiography is a potential risk factor for parenchymal hematoma after revascularization for anterior circulation acute ischemic stroke.

The Dilator-Dotter Technique: A Modified Method of Rapid Internal Carotid Artery Revascularization in Acute Ischemic Stroke.

Acute ischemic stroke due to tandem occlusive lesions involves high-grade ICA stenosis or occlusion with a distal intracranial occlusion. Several approaches and devices exist in the treatment of tandem occlusions; however, a consensus on the optimal technique does not exist. The Dotter technique is a method of catheter-based angioplasty to recanalize cervical ICA occlusions. We present a modified dilator-Dotter technique, which involves a polyethylene, tapered inner dilator to initially cross the occlusion, followed by guide catheterization and subsequent intracranial thrombectomy. The purpose of this study was to examine the safety and efficacy of this dilator-Dotter technique. We performed a retrospective review of patients with acute stroke due to tandem ICA intracranial occlusions, treated with our dilator-Dotter technique and thrombectomy between June 2018 and December 2019. We examined clinical, radiographic, and procedural data, as well as complications and outcomes. Thirty-two patients were included. In 100% of cases, the dilator-Dotter technique resulted in ICA recanalization allowing successful thrombectomy. TICI 2b-3 revascularization was obtained in 31 patients (96%), within an average time of 25 minutes. The average preprocedural ICA stenosis was 98%, including 23 patients (72%) with complete occlusion. Following the dilator-Dotter technique, average ICA stenosis improved to 59%. There were no instances of death, iatrogenic dissection, emboli to new territory, or symptomatic intracranial hemorrhage. The dilator-Dotter technique may be a safe and effective modification of the traditional Dotter technique in allowing rapid ICA recanalization in cases of acute ischemic stroke due to tandem occlusions.

Abstract WP433: Factor Associated With Significant Delay in Acute Stroke Triage Process

Background: Benefit of revascularization in acute ischemic stroke declines over time. Any delay in acute stroke care contributes to poor treatment outcome. We aimed to identify factors associated with the delay in the process of acute stroke triage. Methods: All patients presented at the emergency room at the Siriraj Hospital, Mahidol University, Thailand under stroke fast track protocol (ASFP) from January 2015 to March 2017 were reviewed. Demographic data, stroke subtypes, time measures, initial NIHSS were recorded. Delay in triage was defined as either door to first physician > 10 minutes or door to activate stroke fast track > 15 minutes. Multivariable logistic regression model were performed to identify independent variables associated with triage delay. Results: A total of 1,000 patients were enrolled under ASFP with a mean age of 63.5+15.3 years and 53.9% were male. Triage delay was found in 11.2%. Factors associated with a delay in stroke triage were inaccurate presenting symptom(s) OR17.69 (95% CI 10.86, 28.82), dizziness and dysphagia as an initial presentation OR 3.26 (95% CI 1.64, 6.48) and OR 8.02 (95% CI 1.31, 49.28) respectively and uncertain chief complaint OR 3.35 (95% CI 1.56, 7.19). Conclusion: Unclear chief complaint, dizziness and vertigo as an initial symptoms and inaccurate presenting symptoms significantly associated with the delay in acute stroke triage in an emergency department. Further research is needed to clarify if strategic questioning could help nurses and ER physicians in reducing this delay.

Texture parameters of R2* maps are correlated with iron concentration and red blood cells count in clot analogs: A 7-T micro-MRI study

Background and purposePrevious studies have suggested that mechanical revascularization in acute ischemic stroke (AIS) patients could be affected by clot histology. In this 7-T micro-MRI study, we used R2* relaxometry of clot analogs to evaluate the relationship between texture parameters of R2* maps and clot constituents. Materials and methodsTwelve AIS clot analogs were experimentally generated to obtain a wide range of red blood cell concentrations. All clots underwent a MR acquisition using a 7-T micro-MR system. A 3D multi-echo gradient-echo sequence was performed and R2* maps were generated. First order and second order statistics of R2* histograms within the clots were calculated. Iron concentration in clots was measured using absorption spectrometry and red blood cell count (RBC) was obtained by histopathological analysis. ResultsRBC count was strongly correlated with iron concentration within clots (r=0.87, P<.001). Higher RBC count and iron concentration were significantly correlated with first order parameters including: (a) global positive shift of the R2* histogram with higher ‘10th percentile’, ‘median’, ‘mean’ and ‘90th percentile’; (b) increase of the global magnitude of voxel values with higher ‘total energy’ and ‘root mean squared’; (c) greater uniformity of the voxel values with higher ‘uniformity’ and lower ‘entropy’. Second order statistical parameters confirmed that higher RBC count and iron concentration correlated with (a) greater concentration of high gray-level values in the image; (b) more “coarse” texture of R2* maps. ConclusionsTexture analysis of MRI-R2* maps can accurately estimate the red blood cell count and iron content of AIS clot analogs.

National trends in endovascular therapy for acute ischemic stroke: utilization and outcomes

ObjectiveFollowing widespread acceptance of endovascular therapy (ET) for large vessel occlusion stroke in 2015, we assessed nationwide utilization of revascularization for acute ischemic stroke (AIS).MethodsWe utilized the 2013–2016 Healthcare Cost...

Presence of an Anterior Communicating Artery as a Prognostic Factor in Revascularization for Anterior Circulation Acute Ischemic Stroke

No reports have evaluated collateral circulation using simpler measures involving magnetic resonance imaging. Because an anterior communicating artery (A-com) is important in collateral circulation, we investigated whether the presence of an A-com affected the clinical revascularization outcomes in acute ischemic stroke (AIS) in the anterior circulation. The present retrospective study included 73 patients who had undergone continuous administration of recombinant tissue plasminogen activator and revascularization for AIS in the anterior circulation from April 2014 to September 2018. The presence of an A-com was evaluated using preoperative time-of-flight magnetic resonance angiography. The patient characteristics and clinical outcomes were compared, and we investigated the influence of the presence or absence of an A-com on these clinical outcomes. The clinical outcomes were analyzed using multiple logistic regression. The clinical outcomes did not significantly correlate with age, sex, or occlusion location but did significantly correlate with the preoperative National Institute of Health stroke scale score, diffusion-weighted Alberta Stroke Program early computed tomography score, reperfusion >50% (thrombolysis in cerebral infarction grade >2b), and onset to recanalization time. The presence of an A-com correlated significantly with good clinical outcomes (modified Rankin scale score 0-3; P= 0.0081) and reduced mortality (P= 0.03). Multiple logistic regression predicted for significantly good clinical outcomes with the presence of an A-com (odds ratio, 17.03; 95% confidence interval, 1.85-157.10; P= 0.012). The presence of an A-com on preoperative time-of-flight magnetic resonance angiography is a good prognostic factor for revascularization in patients with anterior circulation AIS, confirms collateral circulation, and allows for faster and safer endovascular treatment.

3224 Impact of aortic arch anatomy on technical performance and clinical outcomes in acute ischemic stroke patients

OBJECTIVES/SPECIFIC AIMS: This study aims to examine the relative impact of aortic arch and carotid artery anatomy on the procedural times and clinical outcomes in patients who have suffered acute ischemic strokes (AIS). Mechanical thrombectomy remains the gold-standard of care for large vessel ischemic stroke. Given that short procedural times are necessary for good clinical outcomes, arterial access is an important technical consideration. It has been recently demonstrated that abnormal carotid artery anatomy can increase endovascular procedure times in this patient population. However, there are no studies examining the impact of aortic arch anatomy on operative times. Additionally, no studies have looked at the impact of aortic arch and carotid artery tortuosity on clinical outcomes in AIS. Thus, we sought to exam the influence of various aortic arch and carotid artery anatomic variables on interventional procedure times and clinical outcomes. METHODS/STUDY POPULATION: We included 56 patients who underwent embolectomy with successful revascularization for acute ischemic stroke in the anterior circulation from a period of 01/2016-05/2018. The average age was 71 (+/− 17 years) with 39% being male. We calculated anatomic variables on the affected side from CT angiograms immediately prior to embolectomy including the medial-to-lateral span, as well as the anterior-to-posterior span, of both the aortic arch and carotid arteries. In addition, the take-off angle of the respective vessel (left common carotid or right brachiocephalic) was calculated. Charts were reviewed for procedural times and epidemiologic information (HTN, HLD, DM, CAD and Afib). Modified Rankin Scale (mRS) was calculated from PT/OT and outpatient neurology notes. Partial correlation coefficients were performed between anatomic variables, temporal variables and outcome variables after adjustment for age, gender and epidemiologic information. RESULTS/ANTICIPATED RESULTS: There was a significant positive correlation between procedure time (time at groin puncture to time at reperfusion) and take-off angle. There were no other significant correlations between anatomic measures and procedure time. In addition, there was as a significant positive correlation between both procedure time and time from last seen normal to reperfusion and delta mRS (the difference between pre-stroke and post-stroke mRS). DISCUSSION/SIGNIFICANCE OF IMPACT: These results suggest that patients with larger take-off angles have an association with longer procedural times and worse outcomes. If these patients can be effectively identified prior to the procedure, operators could feasibly use a non-femoral access method initially to reduce procedure time.

Abstract WP23: Impact of Aortic Arch Anatomy on Technical Performance and Clinical Outcomes in Acute Ischemic Stroke Patients

Introduction: Arterial access is a technical consideration of mechanical thrombectomy that may affect procedure time. Few studies exist detailing the impact of aortic arch and carotid anatomy on procedure times and patient outcomes. Methods: We included 56 patients who underwent embolectomy with successful revascularization for acute ischemic stroke in the anterior circulation from a period of 01/2016-05/2018. The average age was 71 (+/- 17 years) with 39% being male. We calculated anatomic variables on the affected side from CT angiograms immediately prior to embolectomy including the medial-to-lateral span, as well as the anterior-to-posterior span, of both the aortic arch and carotid arteries. In addition, the take-off angle of the respective vessel (left common carotid or right brachiocephalic) was calculated. Charts were reviewed for procedural times and epidemiologic information (HTN, HLD, DM, CAD and Afib). Modified Rankin Scale (mRS) was calculated from PT/OT and outpatient neurology notes. Partial correlation coefficients were performed between anatomic variables, temporal variables and outcome variables after adjustment for age, gender and epidemiologic information. Results: There was a significant positive correlation between procedure time (time at groin puncture to time at reperfusion) and take-off angle. There were no other significant correlations between anatomic measures and procedure time. In addition, there was as a significant positive correlation between both procedure time and time from last seen normal to reperfusion and delta mRS (the difference between pre-stroke and post-stroke mRS). See table 1 for correlations. Conclusion: These results suggest that patients with larger take-off angles have an association with longer procedural times and worse outcomes. If these patients can be effectively identified prior to the procedure, operators could feasibly use a non-femoral access method initially to reduce procedure time.

Approach to Endovascular Revascularization for Acute Ischemic Stroke in Kinki Region

Approach to Endovascular Revascularization for Acute Ischemic Stroke in Kinki Region

Emergency Extracranial-Intracranial Bypass to Revascularize Salvageable Brain Tissue in Acute Ischemic Stroke Patients.

To present an algorithm based on clinical and radiologic factors, including magnetic resonance imaging (MRI) perfusion/diffusion mismatch (PDM), for the indication of urgent cerebral bypass in patients with acute ischemic stroke. Clinical and radiologic data of 8 consecutive patients undergoing urgent cerebral revascularization for acute ischemic stroke owing to occlusion of internal carotid or middle cerebral artery between 2012 and 2015 were analyzed. All patients either were ineligible for or failed first-line treatment with emergent endovascular revascularization. Indication for urgent bypass was based on clinical worsening and MRI PDM, indicating threat for stroke extension. Clinical outcome was measured using National Institutes of Health Stroke Scale and modified Rankin Scale before and after bypass surgery, at 3-month follow-up, and at last follow-up. All patients presented with clinical worsening after initiation of acute stroke treatment. Cerebral revascularization was performed 9.6 hours (SD 9.0) after clinical worsening. All patients had preoperative MRI PDM. No bypass complications, such as anastomosis failure or postoperative hemorrhage, occurred. MRI diffusion ratio before and after bypass was stable or improved in 7 patients and progressed in 1 patient without clinical worsening. MRI PDM and perfusion improved in all 4 patients who underwent postoperative MRI. Clinical outcome was favorable with a median improvement of 7 points on National Institutes of Health Stroke Scale and of 2 points on modified Rankin Scale at last follow-up. Based on an algorithm indicating salvageable brain tissue, cerebral revascularization can be safely performed in an emergency setting in a highly selected group of patients with acute ischemic stroke with favorable clinical outcome.

Transfer to High-Volume Centers Associated With Reduced Mortality After Endovascular Treatment of Acute Stroke.

Some have argued that it may be beneficial to expand the availability of endovascular revascularization services to lower-volume hospitals to minimize the morbidity associated with transfer to larger endovascular centers. We compared the outcomes after revascularization of patients directly admitted to a low-volume center and those transferred to a high-volume center. We searched a national database of hospital-reported outcomes for patients who underwent endovascular revascularization for acute ischemic stroke. Hospitals were categorized as low, medium, or high procedural volume hospitals. Outcomes of inpatient admissions were collected and compared on the basis of admission source and hospital procedural volume. A total of 118 institutions with 8533 patients were included. Mortality rate (14.9% versus 18.6%; P=0.049) and mortality index (1.1 versus 1.6; P=0.048) were significantly lower among directly admitted relative to transferred patients. For all patients, there were significant differences in institutional mortality rate (low: 19.7%, medium: 14.9%, high: 9.8%; P=0.003) and mortality index (low: 1.5, medium: 1.1, high: 0.8; P=0.004) between low-, medium-, and high-volume hospitals. For transferred patients to high-volume centers, both mortality rate (high: 10.0% versus low: 20.4%; P=0.005) and mortality index (high: 0.8 versus low: 1.5; P=0.034) were significantly lower than that observed for directly admitted patients to low-volume hospitals. We report a beneficial effect of treatment at high-volume hospitals in spite of the detrimental effects of transfer. These findings argue for the centralization of care.

Abstract WP411: Evaluation of Strategies to Reduce Time to Revascularization in Acute Ischemic Stroke

Background: There is growing support for the need for process improvement surrounding treatment of acute ischemic stroke, specifically, reducing time to reperfusion in endovascular therapy (EVT). Streamlining protocols from patient presentation to revascularization can lead to improved timelines to treatment and functional outcomes. Purpose: The purpose of this study was to identify the impact on specific hospital based process improvement strategies in the acute ischemic stroke patient population undergoing endovascular therapy with specific intent to decrease median arrival to revascularization time, thus increasing the potential for good functional outcome. Methods: The study includes a pre- and post-intervention retrospective review of patients 18 years or older, hospital admission between January 1, 2014 and December 31, 2015, who underwent EVT for treatment acute ischemic stroke. The primary outcome variable was time from arrival to revascularization during the acute ischemic stroke admission. The secondary outcome variables were specific to functional outcome analysis in the acute ischemic stroke patient. The data points were collected from the local America Heart Association’s Get with the Guidelines-Stroke (GWTG) dataset. Results: Twenty eight consecutive endovascular ischemic stroke patients were reviewed, pre process improvement (PI) (Group 1, n=10) and post PI (Group 2, n=18). There were no significant differences between baseline characteristics between the groups. The primary outcome analysis revealed significant improvement in door to revascularization between the pre and post PI groups, 2:56 and 2:11 (p=.002) respectively, a 45 minute decrease in time to treatment. Rates of good clinical outcomes (modified Rankin Scale 0-2 at 3 months) were similar in both groups, 33.3% pre PI and 46.2% post PI (p=0.59). Conclusions: Hospital based PI initiatives including: early notification, streamlined transport process, and utilization of feedback tool significantly improve door to revascularization times and can potentially lead to improved functional outcomes in the acute ischemic stroke patient undergoing EVT.

Intracranial Hemorrhage after Endovascular Revascularization for Acute Ischemic Stroke

Intracranial Hemorrhage after Endovascular Revascularization for Acute Ischemic Stroke

Hospital transfer associated with increased mortality after endovascular revascularization for acute ischemic stroke

BackgroundPatients with an acute ischemic stroke (AIS) due to large vessel occlusion often require transfer to an endovascular center for treatment.ObjectiveTo assess the effect of hospital transfer on outcomes after...

Imaging-based selection for revascularization in acute ischemic stroke.

With the positive results of recent endovascular thrombectomy (EVT) trials, intravenous thrombolysis (IVT) and EVT provide physicians with two majorly effective acute treatment options for patients with acute ischemic stroke. IVT and EVT can be used as a single treatment or as a combined IVT/EVT treatment approach. This review summarizes how imaging findings can help in selecting stroke patients who are likely to benefit from these revascularization therapies. IVT applied within 4.5 h from symptom onset remains the mainstay of acute stroke therapy and was also applied to most patients in the randomized EVT trials. Recent studies have failed to demonstrate the effectiveness of IVT in later time windows. Vascular imaging is crucial to identify patients with a target intracranial occlusion prior to EVT. Patients with a small ischemic core, with good leptomeningeal collaterals or with evidence of penumbral tissue may particularly benefit from EVT. These imaging findings may also identify patients who benefit from EVT if applied more than 6 h from symptom onset. Pretherapeutic imaging findings help in identifying stroke patients who are likely to benefit from endovascular stroke therapies, and may identify patients who benefit from revascularization therapies in later time windows.