![Jeremy J. Heit, MD, PhD](https://profiles.stanford.edu/proxy/api/cap/profiles/68286/resources/profilephoto/350x350.1509509284978.jpg)
Jeremy J. Heit, MD, PhD
Associate Professor of Radiology (Neuroimaging and Neurointervention) and, by courtesy, of Neurosurgery
Web page: http://www.heitlab.com
Bio
Dr. Jeremy Heit is an Associate Professor of Radiology and of Neurosurgery and the Chief of Neuroimaging and Neurointervention at Stanford University. Dr. Jeremy Heit is a neurointerventional surgeon (neurointerventional radiologist) who specializes in treating stroke, brain aneurysms, brain arteriovenous malformations, brain and spinal dural arteriovenous fistulae, carotid artery stenosis, vertebral body compression fractures, and congenital vascular malformations. Dr. Heit treats all of these conditions using minimally-invasive, image-guided procedures and state-of-the-art technology.
Dr. Heit’s research seeks to understand the genetic, developmental, and pathophysiologic basis of cerebrovascular disease. In addition, his group is developing new minimally invasive, image-guided treatments for ischemic and hemorrhagic stroke. He has authored over 150 publications and is an investigator on multiple grants, including the CRISP 2 and DEFUSE 3 studies. He is the co-PI of the NIH-funded PRECISE basilar thrombectomy study.
For more information about Dr. Heit's research lab, please visit:
www.heitlab.com
Clinical Focus
- Interventional Neuroradiology
- Neurointerventional Surgery
- Neuroradiology
- Stroke
- Cerebral Aneurysms
- Dural Arteriovenous Fistula
- Cerebral Arteriovenous Malformation (AVM)
- Diagnostic Neuroimaging
Academic Appointments
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Associate Professor - University Medical Line, Radiology
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Associate Professor - University Medical Line (By courtesy), Neurosurgery
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Member, Bio-X
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Member, Wu Tsai Neurosciences Institute
Administrative Appointments
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Chief of Neuroimaging and Neurointervention, Stanford University Medical Center (2022 - Present)
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Director, Stroke Neuroradiology, Stanford Stroke Center, Stanford University Hospital (2021 - Present)
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Director, Neurointerventional Surgery Fellowship, Stanford University Medical Center (2018 - Present)
Honors & Awards
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Valedictorian, Regis Jesuit High School, Aurora, CO (5/1996)
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Boettcher Foundation Scholar, Full Academic Scholarship to the University of Colorado at Boulder, Boettcher Foundation (8/1996 – 5/2000)
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Beta Kappa Honor Society, Phi Beta Kappa (4/1997 – present)
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Summa Cum Laude, Department of Biochemisty, University of Colorado at Boulder (5/2000)
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Graduation with Distinction in Molecular, Cellular and Developmental Biology, University of Colorado at Boulder (5/2000)
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Department of Biochemistry Outstanding Graduating Senior Award, University of Colorado at Boulder (5/2000)
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Medical Scientist dual MD/PhD Training Program, Stanford University School of Medicine (8/2000 – 6/2008)
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Chief Resident in Radiology, Massachusetts General Hospital, Boston, MA (3/2011 – 2/2012)
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Roentgen Resident/Fellow Research Award, RSNA Research and Education Foundation, Radiological Society of North America (5/2011)
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Alpha Omega Alpha Medical Honor Society, Alpha Omega Alpha Medical Honor Society, Stanford University Medical School Chapter (5/2019)
Boards, Advisory Committees, Professional Organizations
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Research Committee, American Society of Neuroradiology (2012 - Present)
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Scientific Program Committee, Neuroradiology/Head and Neck Subcommittee, Radiological Society of North America (2018 - Present)
Professional Education
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Board Certification: American Board of Radiology, Neuroradiology (2018)
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Fellowship: Stanford University Radiology Fellowships (2015) CA
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Board Certification: American Board of Radiology, Diagnostic Radiology (2013)
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Residency: Massachusetts General Hospital Radiology Residency (2013) MA
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Internship: Brigham and Women's Hospital Internal Medicine Residency (2009) MA
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Medical Education: Stanford University School of Medicine (2008) CA
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PhD, Stanford University Medical School, Developmental Biology (2007)
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BA, University of Colorado at Boulder, Biochemistry, Summa Cum Laude, and Molecular, Cellular, and Developmental Biology (2000)
Current Research and Scholarly Interests
Our research seeks to advance our understanding of cerebrovascular disease and to develop new minimally invasive treatments for these diseases. We study ischemic and hemorrhagic stroke, cerebral aneurysms, delayed cerebral ischemia, cerebral arteriovenous malformations (AVMs), dural arteriovenous fistulae, and other vascular diseases of the brain. We use state-of-the-art neuroimaging techniques to non-invasively study these diseases, and we are developing future endovascular technologies to advance neurointerventional surgery.
www.heitlab.com
Clinical Trials
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Endovascular Therapy Following Imaging Evaluation for Ischemic Stroke 3
Not Recruiting
This is a study to evaluate the hypothesis that FDA cleared thrombectomy devices plus medical management leads to superior clinical outcomes in acute ischemic stroke patients at 90 days when compared to medical management alone in appropriately selected subjects with the Target mismatch profile and an MCA (M1 segment) or ICA occlusion who can be randomized and have endovascular treatment initiated between 6-16 hours after last seen well.
Stanford is currently not accepting patients for this trial.
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PHIL in the Treatment of Intracranial dAVF.
Not Recruiting
This study is a prospective, multicenter, single-arm study. Patients with Dural Arteriovenous Fistulas (dAVF) have a few choice for safe treatment. In this study, all patients with qualifying dAVFs will be treated with PHIL® Liquid Embolic material.
Stanford is currently not accepting patients for this trial.
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Ruptured Aneurysms Treated With Hydrogel Coils
Not Recruiting
To determine safety and occlusion rates when second-generation hydrogel coils are used in the treatment of ruptured intracranial aneurysms.
Stanford is currently not accepting patients for this trial.
Stanford Advisees
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Postdoctoral Faculty Sponsor
Aroosa Zamarud, Henk van Voorst -
Doctoral Dissertation Reader (NonAC)
Matine Azadian
All Publications
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Clinical and Imaging Features Associated With Fast Infarct Growth During Interhospital Transfers of Patients With Large Vessel Occlusions.
Neurology
2024; 103 (6): e209814
Abstract
BACKGROUND AND OBJECTIVES: Acute ischemic stroke patients with a large vessel occlusion (LVO) who present to a primary stroke center (PSC) often require transfer to a comprehensive stroke center (CSC) for thrombectomy. Not much is known about specific characteristics at the PSC that are associated with infarct growth during transfer. Gaining more insight into these features could aid future trials with cytoprotective agents targeted at slowing infarct growth. We aimed to identify baseline clinical and imaging characteristics that are associated with fast infarct growth rate (IGR) during interhospital transfer.METHODS: We included patients from the CT Perfusion to Predict Response to Recanalization in Ischemic Stroke Project, a prospective multicenter study. Patients with an anterior circulation LVO who were transferred from a PSC to a CSC for consideration of thrombectomy were eligible if imaging criteria were fulfilled. A CT perfusion (CTP) needed to be obtained at the PSC followed by an MRI at the CSC, before consideration of thrombectomy. The interhospital IGR was defined as the difference between the infarct volumes on MRI and CTP, divided by the time between the scans. Multivariable logistic regression was used to determine characteristics associated with fast IGR (≥5 mL/h).RESULTS: A total of 183 patients with a median age of 74 years (interquartile range 61-82), of whom 99 (54%) were male and 82 (45%) were fast progressors, were included. At baseline, fast progressors had a higher NIH Stroke Scale score (median 16 vs 13), lower cerebral blood volume index (median 0.80 vs 0.89), more commonly poor collaterals on CT angiography (35% vs 13%), higher hypoperfusion intensity ratios (HIRs) (median 0.51 vs 0.34), and larger core volumes (median 11.80 mL vs 0.00 mL). In multivariable analysis, higher HIR (adjusted odds ratio [aOR] for every 0.10 increase 1.32 [95% CI 1.10-1.59]) and larger core volume (aOR for every 10 mL increase 1.54 [95% CI 1.20-2.11]) remained independently associated with fast IGR.DISCUSSION: Fast infarct growth during interhospital transfer of acute stroke patients is associated with imaging markers of poor collaterals on baseline imaging. These markers are promising targets for patient selection in cytoprotective trials aimed at reducing interhospital infarct growth.
View details for DOI 10.1212/WNL.0000000000209814
View details for PubMedID 39173104
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Deep venous outflow as a surrogate for collaterals in late-window patients with successful revascularization from the DEFUSE 3 cohort.
Interventional neuroradiology : journal of peritherapeutic neuroradiology, surgical procedures and related neurosciences
2024: 15910199241276905
Abstract
Deep venous outflow (VO) may be an important surrogate marker of collateral blood flow in acute ischemic stroke patients with a large vessel occlusion (AIS-LVO). Researchers have yet to determine the relationship between deep VO status in late-window patients and imaging measures of collaterals, which are key in preserving tissue.We performed a multicenter retrospective cohort study on a subset of DEFUSE 3 patients recruited across 38 centers between May 2016 and May 2017 who underwent successful thrombectomy revascularization. Internal cerebral vein opacification was scored on a scale of 0-2. This metric was added to the cortical vein opacification score to derive the comprehensive VO (CVO) score from 0 to 8. Patients were stratified by favorable (ICV+) and unfavorable (ICV-) ICV scores, and similarly CVO+ and CVO-. Analyses comparing outcomes were primarily conducted by Mann-Whitney U and χ2 tests.Forty-five patients from DEFUSE 3 were scored and dichotomized into CVO+, CVO-, ICV+, and ICV- categories, with comparable demographics. Hypoperfusion intensity ratio, a marker of tissue level collaterals, was significantly worse in the ICV- and CVO- groups (p = 0.005). ICV- alone was also associated with a larger perfusion lesion (138 ml vs 87 ml; p = 0.023). No significant differences were noted in functional and safety outcomes.Impaired deep venous drainage alone may be a marker of poor tissue level collaterals and a greater degree of affected tissue in AIS-LVO patients presenting in the late-window who subsequently undergo successful revascularization.
View details for DOI 10.1177/15910199241276905
View details for PubMedID 39194997
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Decreased Quantitative Cerebral Blood Volume Is Associated With Poor Outcomes in Large Core Patients.
Stroke
2024
Abstract
BACKGROUND: Recent large core trials have highlighted the effectiveness of mechanical thrombectomy (MT) in acute ischemic stroke with large vessel occlusion. Variable perfusion-imaging thresholds and poor Alberta Stroke Program Early Computed Tomography Score reliability underline the need for more standardized, quantitative ischemia measures for MT patient selection. We aimed to identify the computed tomography perfusion parameter most strongly associated with poor outcomes in patients with acute ischemic stroke-large vessel occlusion with significant ischemic cores.METHODS: In this study from 2 comprehensive stroke centers from 2 comprehensive stroke centers within the Johns Hopkins Medical Enterprise (Johns Hopkins Hospita-East Baltimore and Bayview Medical Campus) from July 29, 2019 to January 29, 2023 in a continuously maintained database, we included patients with acute ischemic stroke-large vessel occlusion with ischemic core volumes defined as relative cerebral blood flow <30% and ≥50 mL on computed tomography perfusion or Alberta Stroke Program Early Computed Tomography Score <6. We used receiver operating characteristics to find the optimal cutoff for parameters like cerebral blood volume (CBV) <34%, 38%, 42%, and relative cerebral blood flow >20%, 30%, 34%, 38%, and time-to-maximum >4, 6, 8, and 10 seconds. The primary outcome was unfavorable outcomes (90-day modified Rankin Scale score 4-6). Multivariable models were adjusted for age, sex, diabetes, baseline National Institutes of Health Stroke Scale, intravenous thrombolysis, and MT.RESULTS: We identified 59 patients with large ischemic cores. A receiver operating characteristic curve analysis showed that CBV<42% ≥68 mL is associated with unfavorable outcomes (90-day modified Rankin Scale score 4-6) with an area under the curve of 0.90 (95% CI, 0.82-0.99) in the total and MT-only cohorts. Dichotomizing at this CBV threshold, patients in the ≥68 mL group exhibited significantly higher relative cerebral blood flow, time-to-maximum >8 and 10 seconds volumes, higher CBV volumes, higher HIR, and lower CBV index. The multivariable model incorporating CBV<42% ≥68 mL predicted poor outcomes robustly in both cohorts (area under the curve for MT-only subgroup was 0.87 [95% CI, 0.75-1.00]).CONCLUSIONS: CBV<42% ≥68 mL most effectively forecasts poor outcomes in patients with large-core stroke, confirming its value alongside other parameters like time-to-maximum in managing acute ischemic stroke-large vessel occlusion.
View details for DOI 10.1161/STROKEAHA.124.047483
View details for PubMedID 39185560
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Assessment of Thrombectomy versus Combined Thrombolysis and Thrombectomy in Patients with Acute Ischemic Stroke and Medium Vessel Occlusion.
Radiology
2024; 312 (2): e233041
Abstract
Background The combination of intravenous thrombolysis (IVT) with mechanical thrombectomy (MT) may have clinical benefits for patients with medium vessel occlusion. Purpose To examine whether MT combined with IVT is associated with different outcomes than MT alone in patients with acute ischemic stroke (AIS) and medium vessel occlusion. Materials and Methods This retrospective study included consecutive adult patients with AIS and medium vessel occlusion treated with MT or MT with IVT at 37 academic centers in North America, Asia, and Europe. Data were collected from September 2017 to July 2021. Propensity score matching was performed to reduce confounding. Univariable and multivariable logistic regression analyses were performed to test the association between the addition of IVT treatment and different functional and safety outcomes. Results After propensity score matching, 670 patients (median age, 75 years [IQR, 64-82 years]; 356 female) were included in the analysis; 335 underwent MT alone and 335 underwent MT with IVT. Median onset to puncture (350 vs 210 minutes, P < .001) and onset to recanalization (397 vs 273 minutes, P < .001) times were higher in the MT group than the MT with IVT group, respectively. In the univariable regression analysis, the addition of IVT was associated with higher odds of a modified Rankin Scale (mRS) score 0-2 (odds ratio [OR], 1.44; 95% CI: 1.06, 1.96; P = .019); however, this association was not observed in the multivariable analysis (OR, 1.37; 95% CI: 0.99, 1.89; P = .054). In the multivariable analysis, the addition of IVT also showed no evidence of an association with the odds of first-pass effect (OR, 1.27; 95% CI: 0.9, 1.79; P = .17), Thrombolysis in Cerebral Infarction grades 2b-3 (OR, 1.64; 95% CI: 0.99, 2.73; P = .055), mRS scores 0-1 (OR, 1.27; 95% CI: 0.91, 1.76; P = .16), mortality (OR, 0.78; 95% CI: 0.49, 1.24; P = .29), or intracranial hemorrhage (OR, 1.25; 95% CI: 0.88, 1.76; P = .21). Conclusion Adjunctive IVT may not provide benefit to MT in patients with AIS caused by distal and medium vessel occlusion. © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Wojak in this issue.
View details for DOI 10.1148/radiol.233041
View details for PubMedID 39105645
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Dual-Energy CTA Iodine Map Reconstructions Improve Visualization of Residual Cerebral Aneurysms following Endovascular Coiling.
AJNR. American journal of neuroradiology
2024
Abstract
Material-specific reconstructions of dual-energy CTA (DECTA) can highlight iodinated contrast, subtract predefined materials, and reduce metal artifact. We present a technique to improve detection of residual aneurysms after endovascular coiling by which iodine-map DECTA (IM-DECTA) reconstructions subtract platinum coil artifacts in MIP images (MIP IM-DECTA) and assess if IM-DECTA offers improved detection over conventional CTA (CCTA) or monoenergetic DECTA.We included consecutive patients who underwent endovascular aneurysm coiling with follow-up DECTA and DSA within 24 months. DECTA was performed at 80- and 150-kVp tube voltages on a rapid kV-switching single-source Revolution scanner. CCTA and IM-DECTA series were reconstructed. Reference-standard DSA was compared with CCTA, 50- and 70-keV virtual monochromatic DECTA, IM-DECTA, and MIP IM-DECTA. Blinded to DSA data, cross-section images were reviewed in consensus by 3 neurointerventionalists for residual aneurysms and assigned modified Raymond-Roy classifications (mRRC). Sensitivity, specificity, and accuracy of each series is reported relative to DSA, and single-factor ANOVA and pair-wise Spearman correlation coefficients compared the accuracy of each series. Readers provided ROI measurements of HU deviation adjacent to the aneurysm neck for quantitative noise assessment and qualitatively scored each series on a 3-point Likert-style scale ranging from uninterpretable to excellent image quality.Twenty-one patients with 25 coiled aneurysms were included. Mean time from DECTA to DSA was 286 ± 212 days. IM-DECTA and MIP IM-DECTA most sensitively (89% and 90%) and specifically (93% and 93%) detected residual aneurysms relative to CCTA (6% and 86%). Relative to DSA, IM-DECTA and MIP IM-DECTA most accurately detected (92% versus 28% for CCTA) and classified residual aneurysms by mRRC (ρC-CTA = -0.08; ρIM = 0.50; ρIM-MIP = 0.55; P < .001). Reader consensus reported the best image quality at the aneurysm neck with IM-DECTA and MIP IM-DECTA, with 56% of CCTAs considered uninterpretable versus 0% of IM-DECTAs, and image noise was significantly lower for IM-DECTA (27.9 ± 3.6 HU) or MIP IM-DECTA (26.8 ± 3.5 HU) than CCTA (103.2 ± 13.3 HU; P < .001).MIP IM-DECTA can subtract coil mass artifact and is more sensitive and specific than CCTA for the detection of residual aneurysms after endovascular coiling.
View details for DOI 10.3174/ajnr.A8305
View details for PubMedID 39089873
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Pretreatment Predictors of Very Poor Clinical Outcomes in Medium Vessel Occlusion Stroke Patients Treated with Mechanical Thrombectomy.
International journal of stroke : official journal of the International Stroke Society
2024: 17474930241270524
Abstract
BACKGROUND: Acute ischemic stroke (AIS) from primary medium vessel occlusions (MeVO) is a prevalent condition associated with substantial morbidity and mortality. Despite the common use of mechanical thrombectomy (MT) in AIS, predictors of poor outcomes in MeVO remain poorly characterized.METHODS: In this prospectively collected, retrospectively reviewed, multicenter, multinational study, data from the MAD-MT registry were analyzed. The study included 1,568 patients from 37 academic centers across North America, Asia, and Europe, treated with mechanical thrombectomy (MT), with or without intravenous tissue plasminogen activator (IVtPA), between September 2017 and July 2021.RESULTS: Among the 1,568 patients, 347 (22.2%) experienced very poor outcomes (mRS 5-6). Key predictors of poor outcomes were advanced age (OR: 1.03; 95% CI: 1.02 to 1.04; p < 0.001), higher baseline NIHSS scores (OR: 1.07; 95% CI: 1.05 to 1.10; p < 0.001), pre-operative glucose levels (OR: 1.01; 95% CI: 1.00 to 1.02; p < 0.001), and a baseline mRS of 4 (OR: 2.69; 95% CI: 1.25 to 5.82; p = 0.011). The multivariable model demonstrated good predictive accuracy with an area under the receiver operating characteristic (ROC) curve of 0.76.CONCLUSIONS: This study demonstrates that advanced age, higher NIHSS scores, elevated pre-stroke mRS, and pre-operative glucose levels significantly predict very poor outcomes in AIS-MeVO patients who received MT. These findings highlight the importance of a comprehensive risk assessment in primary MeVO patients for personalized treatment strategies. However, they also suggest a need for cautious patient selection for endovascular thrombectomy. Further prospective studies are needed to confirm these findings and explore targeted therapeutic interventions.
View details for DOI 10.1177/17474930241270524
View details for PubMedID 39075759
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Simplifying venous outflow: Prolonged venous transit as a novel qualitative marker correlating with acute stroke outcomes.
The neuroradiology journal
2024: 19714009241269475
Abstract
BACKGROUND: Prolonged venous transit (PVT), defined as presence of time-to-maximum ≥ 10 s within the superior sagittal sinus (SSS) and/or torcula, is a novel, qualitatively assessed computed tomography perfusion surrogate parameter of venous outflow with potential utility in pretreatment acute ischemic stroke imaging for neuroprognostication. We aim to characterize the correlation between PVT and neurological functional outcomes in thrombectomy-treated patients.METHODS: A prospectively-collected database of large vessel occlusion acute ischemic stroke patients treated with thrombectomy was retrospectively analyzed. Spearman's rank correlation coefficient and point-biserial correlations were performed between PVT status (i.e., no region, either SSS or torcula, or both), 90-day modified Rankin score (mRS), mortality (mRS 6), and poor functional outcome (mRS 4-6 vs 0-3).RESULTS: Of 128 patients, correlation between PVT and 90-day mRS (rho = 0.35, p < 0.0001), mortality (r = 0.26, p = 0.002), and poor functional outcome (r = 0.27, p = 0.002) were significant.CONCLUSION: There is a modest, significant correlation between PVT and severity of neurological functional outcome. Consequently, PVT is an easily-ascertained, qualitative metric that may be useful as an adjunct for anticipating a patient's clinical course. Future analyses will determine the significance of incorporating PVT in clinical decision-making.
View details for DOI 10.1177/19714009241269475
View details for PubMedID 39067016
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Endovascular therapy versus best medical management in distal medium middle cerebral artery acute ischaemic stroke: a multinational multicentre propensity score-matched study.
Journal of neurology, neurosurgery, and psychiatry
2024
Abstract
BACKGROUND: The efficacy of endovascular treatment (EVT) in acute ischaemic stroke due to distal medium vessel occlusion (DMVO) remains uncertain. Our study aimed to evaluate the safety and efficacy of EVT compared with the best medical management (BMM) in DMVO.METHODS: In this prospectively collected, retrospectively reviewed, multicentre cohort study, we analysed data from the Multicentre Analysis of primary Distal medium vessel occlusions: effect of Mechanical Thrombectomy registry. Patients with acute ischaemic stroke due to DMVO in the M2, M3 and M4 segments who underwent EVT or received BMM were included. Primary outcome measures comprised 10 co-primary endpoints, including functional independence (mRS 0-2), excellent outcome (mRS 0-1), mortality (mRS 6) and haemorrhagic complications. Propensity score matching was employed to balance the cohorts.RESULTS: Among 2125 patients included in the primary analysis, 1713 received EVT and 412 received BMM. After propensity score matching, each group comprised 391 patients. At 90 days, no significant difference was observed in achieving mRS 0-2 between EVT and BMM (adjusted OR 1.00, 95%CI 0.67 to 1.50, p>0.99). However, EVT was associated with higher rates of symptomatic intracerebral haemorrhage (8.4% vs 3.0%, adjusted OR 3.56, 95%CI 1.69 to 7.48, p<0.001) and any intracranial haemorrhage (37% vs 19%, adjusted OR 2.61, 95%CI 1.81 to 3.78, p<0.001). Mortality rates were similar between groups (13% in both, adjusted OR 1.48, 95%CI 0.87 to 2.51, p=0.15).CONCLUSION: Our findings suggest that while EVT does not significantly improve functional outcomes compared with BMM in DMVO, it is associated with higher risks of haemorrhagic complications. These results support a cautious approach to the use of EVT in DMVO and highlight the need for further prospective randomised trials to refine treatment strategies.
View details for DOI 10.1136/jnnp-2024-333669
View details for PubMedID 39043567
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Symptomatic intracerebral hemorrhage in proximal and distal medium middle cerebral artery occlusion patients treated with mechanical thrombectomy.
Journal of neurointerventional surgery
2024
Abstract
BACKGROUND: Acute ischemic stroke (AIS) caused by distal medium vessel occlusions (DMVOs) represents a significant proportion of overall stroke cases. While intravenous thrombolysis (IVT) has been a primary treatment, advancements in endovascular procedures have led to increased use of mechanical thrombectomy (MT) in DMVO stroke patients. However, symptomatic intracerebral hemorrhage (sICH) remains a critical complication of AIS, particularly after undergoing intervention. This study aims to identify factors associated with sICH in DMVO stroke patients undergoing MT.METHODS: This retrospective analysis utilized data from the Multicenter Analysis of Distal Medium Vessel Occlusions: Effect of Mechanical Thrombectomy (MAD-MT) registry, involving 37 centers across North America, Asia, and Europe. Middle cerebral artery (MCA) DMVO stroke patients were included. The primary outcome measured was sICH, as defined per the Heidelberg Bleeding Classification. Univariable and multivariable logistic regression were used to identify factors independently associated with sICH.RESULTS: Among 1708 DMVO stroke patients, 148 (8.7%) developed sICH. Factors associated with sICH in DMVO patients treated with MT included older age (adjusted odds ratio (aOR) 1.01, 95% confidence interval (95% CI) 1.00 to 1.03, P=0.048), distal occlusion site (M3, M4) compared with medium occlusions (M2) (aOR 1.71, 95% CI 1.07 to 2.74, P=0.026), prior use of antiplatelet drugs (aOR 2.06, 95% CI 1.41 to 2.99, P<0.001), lower Alberta Stroke Program Early CT Scores (ASPECTS) (aOR 0.75, 95% CI 0.66 to 0.84, P<0.001), higher preoperative blood glucose level (aOR 1.00, 95% CI 1.00 to 1.01, P=0.012), number of passes (aOR 1.27, 95% CI 1.15 to 1.39, P<0.001), and successful recanalization (Thrombolysis In Cerebral Infarction (TICI) 2b-3) (aOR 0.43, 95% CI 0.28 to 0.66, P<0.001).CONCLUSION: This study provides novel insight into factors associated with sICH in patients undergoing MT for DMVO, emphasizing the importance of age, distal occlusion site, prior use of antiplatelet drugs, lower ASPECTS, higher preoperative blood glucose level, and procedural factors such as the number of passes and successful recanalization. Pending confirmation, consideration of these factors may improve personalized treatment strategies.
View details for DOI 10.1136/jnis-2024-021879
View details for PubMedID 38977305
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Neurological outcomes for patients meeting radiographic criteria for DEFUSE 3 and SELECT2.
Journal of neurointerventional surgery
2024
Abstract
The DEFUSE 3 and SELECT2 thrombectomy trials included some patients with similar radiographic profiles, although the rates of good functional outcomes differed widely between the studies.To report neurological outcomes for patients who meet CT and CT perfusion (CTP) inclusion criteria common to both DEFUSE 3 and SELECT2.Retrospective study of thrombectomy patients, presenting between November 2016 and December 2023 to a large health system, with Alberta Stroke Program Early CT score ≥6, core infarction 50-69 mL, mismatch ratio ≥1.8, and mismatch volume ≥15 mL. The primary outcome was 90-day modified Rankin Scale score 0-2. A logistic regression analysis was performed to identify independent predictors of the primary outcome.85 patients, with mean age 64.6 (16.6) years and median National Institutes of Health Stroke Scale score 18 (15-23), were included. Thirty-eight of 85 patients (44.7%) were functionally independent at 90 days. Predictors of functional independence included age (OR=0.943, 95% CI 0.908 to 0.980; P=0.003), initial glucose (OR=0.989, 95% CI 0.978 to 1.000; P=0.044), and time last known well to skin puncture (OR=0.997, 95% CI 0.994 to 1.000; P=0.028). The area under the curve for the multivariable model predicting the primary outcome was 0.82 (95% CI 0.73 to 0.92).Nearly half of patients meeting radiographic criteria common to DEFUSE 3 and SELECT2 are functionally independent at 90 days, similar to rates reported for the treated DEFUSE 3 cohort. This might be due to their moderate core volumes and large ischemic penumbra.
View details for DOI 10.1136/jnis-2024-021976
View details for PubMedID 38969496
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Multicenter evaluation of mechanical thrombectomy for distal medium vessel occlusions with National Institute of Health Stroke Scale Scores≥6 and≤6.
Journal of neurology
2024
Abstract
BACKGROUND: While mechanical thrombectomy is considered standard of care for large vessel occlusions, scientific evidence to support treatment for distal and medium vessel occlusions remains scarce.PURPOSE: To evaluate feasibility, safety, and outcomes in patients with low National Institute of Health Stroke Scale scores undergoing mechanical thrombectomy for treatment of distal medium vessel occlusions.MATERIALS AND METHODS: Retrospective data review and analysis of prospectively maintained databases at 41 academic centers in North America, Asia, and Europe between January 2017 and January 2022. Characteristics and outcomes were compared between groups with low stroke scale score (≤6) versus and higher stroke scale scores (>6). Propensity score matching using the optimal pair matching method and 1:1 ratio was performed.RESULTS: Data were collected on a total of 1068 patients. After propensity score matching, there were a total of 676 patients included in the final analysis, with 338 patients in each group. High successful reperfusion rates were seen in both groups, 90.2% in≤6 and 88.7% in the>6 stroke scale groups. The frequency of excellent and good functional outcome was seen more common in low versus higher stroke scale score patients (64.5% and 81.1% versus 39.3% and 58.6%, respectively). The 90-day mortality rate observed in the≤6 stroke scale group was 5.3% versus 13.3% in the>6 stroke scale group.CONCLUSION: Mechanical thrombectomy in distal and medium vessel occlusions, specifically in patients with low stroke scale scores is feasible, though it may not necessarily improve outcomes over IVT.
View details for DOI 10.1007/s00415-024-12537-4
View details for PubMedID 38967650
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Overestimation of the Ischemic Core Is Associated With Higher Core Lesion Volume and Degree of Reperfusion After Thrombectomy.
Radiology
2024; 312 (1): e231750
Abstract
Background CT perfusion (CTP)-derived baseline ischemic core volume (ICV) can overestimate the true extent of infarction, which may result in exclusion of patients with ischemic stroke from endovascular treatment (EVT). Purpose To determine whether ischemic core overestimation is associated with larger ICV and degree of recanalization. Materials and Methods This retrospective multicenter cohort study included patients with acute ischemic stroke triaged at multimodal CT who underwent EVT between January 2015 and January 2022. The primary outcome was ischemic core overestimation, which was assumed when baseline CTP-derived ICV was larger than the final infarct volume at follow-up imaging. The secondary outcome was functional independence defined as modified Rankin Scale scores of 0-2 90 days after EVT. Successful vessel recanalization was defined as extended Thrombolysis in Cerebral Infarction score of 2b or higher. Categorical variables were compared between patients with ICV of 50 mL or less versus large ICV greater than 50 mL with use of the χ2 test. Adjusted multivariable logistic regression analyses were used to assess the primary and secondary outcomes. Results In total, 721 patients (median age, 76 years [IQR, 64-83 years]; 371 female) were included, of which 162 (22%) demonstrated ischemic core overestimation. Core overestimation occurred more often in patients with ICV greater than 50 mL versus 50 mL or less (48% vs 16%; P < .001) and those with successful versus unsuccessful vessel recanalization (26% vs 13%; P < .001). In an adjusted model, successful recanalization after EVT (odds ratio [OR], 3.14 [95% CI: 1.65, 5.95]; P < .001) and larger ICV (OR, 1.03 [95% CI: 1.02, 1.04]; P < .001) were independently associated with core overestimation, while the time from symptom onset to imaging showed no association (OR, 0.99; P = .96). Core overestimation was independently associated with functional independence (adjusted OR, 2.83 [95% CI: 1.66, 4.81]; P < .001) after successful recanalization. Conclusion Ischemic core overestimation occurred more frequently in patients presenting with large CTP-derived ICV and successful vessel recanalization compared with those with unsuccessful recanalization. © RSNA, 2024 Supplemental material is available for this article.
View details for DOI 10.1148/radiol.231750
View details for PubMedID 39078297
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Advancing diagnostic precision of delayed cerebral ischemia in aneurysmal subarachnoid hemorrhage: The potential for a vasospasm index score on perfusion imaging to detect vasospasm.
European journal of radiology
2024; 178: 111578
Abstract
The occurrence of delayed cerebral ischemia and vasospasm following aneurysmal subarachnoid hemorrhage (aSAH) results in high morbidity and mortality, but the diagnosis remains challenging. This study aimed to identify neuroimaging perfusion parameters indicative of delayed cerebral ischemia in patients with suspected vasospasm.This is a case-control study. Cases were adult aSAH patients who underwent magnetic resonance perfusion or computed tomography perfusion (CTP) imaging ≤ 24 h before digital subtraction angiography performed for vasospasm diagnosis and treatment. Controls were patients without aSAH who underwent CTP. Quantitative perfusion parameters at different thresholds, including Tmax 4-6-8-10 s delay, cerebral blood flow and cerebral blood volume were measured and compared between cases and controls. The Vasospasm Index Score was calculated as the ratio of brain volume with time-to-max (Tmax) delay > 6 s over volume with Tmax > 4 s.54 patients with aSAH and 119 controls without aSAH were included. Perfusion parameters with the strongest prediction of vasospasm on cerebral angiography were the combination of the Vasospasm Index Score (Tmax6/Tmax4) + CBV ≤ 48 % (area under the curve value of 0.85 [95 % CI 0.78-0.91]) with a sensitivity of 63 % and specificity of 95 %.The Vasospasm Index Score in combination with CBV ≤ 48 % on cerebral perfusion imaging reliably identified vasospasm as the cause of DCI on perfusion imaging.
View details for DOI 10.1016/j.ejrad.2024.111578
View details for PubMedID 38981177
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Predictors of Futile Recanalization in Ischemic Stroke Patients with low baseline NIHSS.
International journal of stroke : official journal of the International Stroke Society
2024: 17474930241264737
Abstract
There is yet no randomized controlled evidence that mechanical thrombectomy (MT) is superior to best medical treatment in patients with large vessel occlusion but minor stroke symptoms (National Institutes of Health Stroke Scale [NIHSS] <6). Prior studies of patients with admission NIHSS scores >6 observed unfavorable functional outcomes despite successful recanalization, commonly termed as futile recanalization (FR), in up to 50% of cases.The aim of this study is to determine the prevalence of FR in patients with minor stroke and identify associated patient-specific risk factors.Our multicenter cohort study screened all patients prospectively enrolled in the German Stroke Registry Endovascular Treatment from 2015 to 2021 (n=13082). Included were patients who underwent MT for anterior circulation vessel occlusion with a baseline NIHSS score of <6 and successful recanalization (modified Thrombolysis in Cerebral Infarction [mTICI] score of 2b-3). FR was defined by a modified Rankin Scale (mRS) score of 2-6 at 90 days. Multivariable logistic regression analysis was conducted to explore factors associated with FR.A total of 674 patients met the inclusion criteria. FR occurred in 268 (40%) patients. Multivariable logistic regression analysis indicates that higher age (adjusted odds ratio: 1.04 [95% confidence interval: 1.02-1.06]), pre-stroke mRS 1 (aOR: 2.70 [1.51-4.84]), transfer from admission hospital to comprehensive stroke center (aOR: 1.67 [1.08-2.56]), longer time from symptom onset/last seen well to admission (aOR: 1.02 [1.00-1.04]), MT under general anesthesia (aOR: 1.78 [1.13-2.82]), higher NIHSS after 24 hours (aOR: 1.09 [1.05-1.14]), and symptomatic intracranial hemorrhage (aOR: 16.88 [2.03-140.14]) increased the odds of FR. There was no significant difference in primary outcome between achieving mTICI 2b or 3.Unfavorable functional outcomes despite successful vessel recanalization were frequent in acute ischemic stroke patients with low NIHSS scores on admission. We provide patient-specific risk factors that indicate an increased risk of FR and should be considered when treating patients with minor stroke.The data that support the findings of our study are available on reasonable request after approval of the GSR steering committee.
View details for DOI 10.1177/17474930241264737
View details for PubMedID 38888031
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Exploring the Limits of Endovascular Therapy for Large Core Patients: Where Do We Need More Data?
Stroke
2024
View details for DOI 10.1161/STROKEAHA.124.047228
View details for PubMedID 38836345
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Lower admission stroke severity is associated with good collateral status in distal medium vessel occlusion stroke.
Journal of neuroimaging : official journal of the American Society of Neuroimaging
2024
Abstract
BACKGROUND AND PURPOSE: Distal medium vessel occlusions (DMVOs) are a significant contributor to acute ischemic stroke (AIS), with collateral status (CS) playing a pivotal role in modulating ischemic damage progression. We aimed to explore baseline characteristics associated with CS in AIS-DMVO.METHODS: This retrospective analysis of a prospectively collected database enrolled 130 AIS-DMVO patients from two comprehensive stroke centers. Baseline characteristics, including patient demographics, admission National Institutes of Health Stroke Scale (NIHSS) score, admission Los Angeles Motor Scale (LAMS) score, and co-morbidities, including hypertension, hyperlipidemia, diabetes, coronary artery disease, atrial fibrillation, and history of transient ischemic attack or stroke, were collected. The analysis was dichotomized to good CS, reflected by hypoperfusion index ratio (HIR) <.3, versus poor CS, reflected by HIR ≥.3.RESULTS: Good CS was observed in 34% of the patients. As to the occluded location, 43.8% occurred in proximal M2, 16.9% in mid M2, 35.4% in more distal middle cerebral artery, and 3.8% in distal anterior cerebral artery. In multivariate logistic analysis, a lower NIHSS score and a lower LAMS score were both independently associated with a good CS (odds ratio [OR]: 0.88, 95% confidence interval [CI]: 0.82-0.95, p<.001 and OR: 0.77, 95% CI: 0.62-0.96, p=.018, respectively). Patients with poor CS were more likely to manifest as moderate to severe stroke (29.1% vs. 4.5%, p<.001), while patients with good CS had a significantly higher chance of having a minor stroke clinically (40.9% vs. 12.8%, p<.001).CONCLUSIONS: CS remains an important determinant in the severity of AIS-DMVO. Collateral enhancement strategies may be a worthwhile pursuit in AIS-DMVO patients with more severe initial stroke presentation, which can be swiftly identified by the concise LAMS and serves as a proxy for underlying poor CS.
View details for DOI 10.1111/jon.13208
View details for PubMedID 38797931
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Arterial Recanalization During Interhospital Transfer for Thrombectomy.
Stroke
2024
Abstract
Patients with acute ischemic stroke harboring a large vessel occlusion admitted to nonendovascular-capable centers often require interhospital transfer for thrombectomy. We evaluated the incidence and predictors of arterial recanalization during transfer, as well as the relationship between interhospital recanalization and clinical outcomes.We analyzed data from 2 cohorts of patients with an anterior circulation large vessel occlusion transferred for consideration of thrombectomy to a comprehensive center, with arterial imaging at the referring hospital and on comprehensive stroke center arrival. Interhospital recanalization was determined by comparison of the baseline and posttransfer arterial imaging and was defined as revised arterial occlusive lesion (rAOL) score 2b to 3. Pretransfer variables independently associated with interhospital recanalization were studied using multivariable logistic regression analysis.Of the 520 included patients (Montpellier, France, n=237; Stanford, United States, n=283), 111 (21%) experienced interhospital recanalization (partial [rAOL=2b] in 77% and complete [rAOL=3] in 23%). Pretransfer variables independently associated with recanalization were intravenous thrombolysis (adjusted odds ratio, 6.8 [95% CI, 4.0-11.6]), more distal occlusions (intracranial carotid occlusion as reference: adjusted odds ratio, 2.0 [95% CI, 0.9-4.5] for proximal first segment of the middle cerebral artery, 5.1 [95% CI, 2.3-11.5] for distal first segment of the middle cerebral artery, and 5.0 [95% CI, 2.1-11.8] for second segment of the middle cerebral artery), and smaller clot burden (clot burden score 0-4 as reference: adjusted odds ratio, 3.4 [95% CI, 1.5-7.6] for 5-7 and 5.6 [95% CI, 2.4-12.7] for 8-9). Recanalization on arrival at the comprehensive center was associated with less interhospital infarct growth (rAOL, 0-2a: 11.6 mL; rAOL, 2b: 2.2 mL; rAOL, 3: 0.6 mL; Ptrend<0.001) and greater interhospital National Institutes of Health Stroke Scale score improvement (0 versus -5 versus -6; Ptrend<0.001). Interhospital recanalization was associated with reduced 3-month disability (adjusted common odds ratio, 2.51 [95% CI, 1.68-3.77]) with greater benefit from complete than partial recanalization.Recanalization is frequently observed during interhospital transfer for thrombectomy and is strongly associated with favorable outcomes, even when partial. Broadening thrombolysis indications in primary centers, and developing therapies that increase recanalization during transfer, will likely improve clinical outcomes.
View details for DOI 10.1161/STROKEAHA.124.046694
View details for PubMedID 38752736
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The Los Angeles motor scale (LAMS) is independently associated with CT perfusion collateral status markers.
Journal of clinical neuroscience : official journal of the Neurosurgical Society of Australasia
2024; 125: 32-37
Abstract
The Los Angeles Motor Scale (LAMS) is an objective tool that has been used to rapidly assess and predict the presence of large vessel occlusion (LVO) in the pre-hospital setting successfully in several studies. However, studies assessing the relationship between LAMS score and CT perfusion collateral status (CS) markers such as cerebral blood volume (CBV) index, and hypoperfusion intensity ratio (HIR) are sparse. Our study therefore aims to assess the association of admission LAMS score with established CTP CS markers CBV Index and HIR in AIS-LVO cases.In this prospectively collected, retrospectively reviewed analysis, inclusion criteria were as follows: a) CT angiography (CTA) confirmed anterior circulation LVO from 9/1/2017 to 10/01/2023, and b) diagnostic CT perfusion (CTP). Logistic regression analysis was performed to assess the relationship between admission LAMS with CTP CS markers HIR and CBV Index. p ≤ 0.05 was considered significant.In total, 285 consecutive patients (median age = 69 years; 56 % female) met our inclusion criteria. Multivariable logistic regression analysis adjusting for sex, age, ASPECTS, tPA, premorbid mRS, admission NIH stroke scale, prior history of TIA, stroke, atrial fibrillation, diabetes mellitus, hyperlipidemia, coronary artery disease and hypertension, admission LAMS was found to be independently associated with CBV Index (adjusted OR:0.82, p < 0.01), and HIR (adjusted OR:0.59, p < 0.05).LAMS is independently associated with CTP CS markers, CBV index and HIR. This finding suggests that LAMS may also provide an indirect estimate of CS.
View details for DOI 10.1016/j.jocn.2024.05.005
View details for PubMedID 38735251
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Outcomes of mechanical thrombectomy in anticoagulated patients with acute distal and medium vessel stroke.
European stroke journal
2024: 23969873241249295
Abstract
BACKGROUND: Stroke remains a major health concern globally, with oral anticoagulants widely prescribed for stroke prevention. The efficacy and safety of mechanical thrombectomy (MT) in anticoagulated patients with distal medium vessel occlusions (DMVO) are not well understood.METHODS: This retrospective analysis involved 1282 acute ischemic stroke (AIS) patients who underwent MT in 37 centers across North America, Asia, and Europe from September 2017 to July 2023. Data on demographics, clinical presentation, treatment specifics, and outcomes were collected. The primary outcomes were functional outcomes at 90days post-MT, measured by modified Rankin Scale (mRS) scores. Secondary outcomes included reperfusion rates, mortality, and hemorrhagic complications.RESULTS: Of the patients, 223 (34%) were on anticoagulation therapy. Anticoagulated patients were older (median age 78 vs 74years; p<0.001) and had a higher prevalence of atrial fibrillation (77% vs 26%; p<0.001). Their baseline National Institutes of Health Stroke Scale (NIHSS) scores were also higher (median 12 vs 9; p=0.002). Before propensity score matching (PSM), anticoagulated patients had similar rates of favorable 90-day outcomes (mRS 0-1: 30% vs 37%, p=0.1; mRS 0-2: 47% vs 50%, p=0.41) but higher mortality (26% vs 17%, p=0.008). After PSM, there were no significant differences in outcomes between the two groups.CONCLUSION: Anticoagulated patients undergoing MT for AIS due to DMVO did not show significant differences in 90-day mRS outcomes, reperfusion, or hemorrhage compared to non-anticoagulated patients after adjustment for covariates.
View details for DOI 10.1177/23969873241249295
View details for PubMedID 38726983
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Low Cerebral Blood Volume Index, Thrombectomy, and Prior Stroke Are Independently Associated With Hemorrhagic Transformation in Medium-Vessel Occlusion Ischemic Stroke
STROKE-VASCULAR AND INTERVENTIONAL NEUROLOGY
2024; 4 (3)
View details for DOI 10.1161/SVIN.123.001250
View details for Web of Science ID 001215306400021
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Outcomes with General Anesthesia Compared to Conscious Sedation for Endovascular Treatment of Medium Vessel Occlusions: Results of an International Multicentric Study.
Clinical neuroradiology
2024
Abstract
BACKGROUND: Optimal anesthetic strategy for the endovascular treatment of stroke is still under debate. Despite scarce data concerning anesthetic management for medium and distal vessel occlusions (MeVOs) some centers empirically support ageneral anesthesia (GA) strategy in these patients.METHODS: We conducted an international retrospective study of MeVO cases. Apropensity score matching algorithm was used to mitigate potential differences across patients undergoing GA and conscious sedation (CS). Comparisons in clinical and safety outcomes were performed between the two study groups GA and CS. The favourable outcome was defined as amodified Rankin Scale (mRS) 0-2 at 90days. Safety outcomes were 90-days mortality and symptomatic intracranial hemorrhage (sICH). Predictors of afavourable outcome and sICH were evaluated with backward logistic regression.RESULTS: After propensity score matching 668 patients were included in the CS and 264 patients in the GA group. In the matched cohort, either strategy CS or GA resulted in similar rates of good functional outcomes (50.1% vs. 48.4%), and successful recanalization (89.4% vs. 90.2%). The GA group had higher rates of 90-day mortality (22.6% vs. 16.5%, p <0.041) and sICH (4.2% vs. 0.9%, p =0.001) compared to the CS group. Backward logistic regression did not identify GA vs CS as apredictor of good functional outcome (OR for GA vs CS =0.95 (0.67-1.35)), but GA remained asignificant predictor of sICH (OR =5.32, 95% CI 1.92-14.72).CONCLUSION: Anaesthetic strategy in MeVOs does not influence favorable outcomes or final successful recanalization rates, however, GA may be associated with an increased risk of sICH and mortality.
View details for DOI 10.1007/s00062-024-01415-1
View details for PubMedID 38687365
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Focused update to guidelines for endovascular therapy for emergent large vessel occlusion: basilar artery occlusion patients.
Journal of neurointerventional surgery
2024
Abstract
Endovascular therapy (EVT) dramatically improves clinical outcomes for patients with anterior circulation emergent large vessel occlusion (ELVO) strokes. With recent publication of two randomized controlled trials in favor of EVT for basilar artery occlusions, the Society of NeuroInterventional Surgery (SNIS) Standards and Guidelines Committee provides this focused update for the existing SNIS guideline, 'Current endovascular strategies for posterior circulation large vessel occlusion stroke.'A structured literature review and analysis of studies related to posterior circulation large vessel occlusion (basilar or vertebral artery) strokes treated by EVT was performed. Based on the strength and quality of the evidence, recommendations were made by consensus of the writing committee, with additional input from the full SNIS Standards and Guidelines Committee and the SNIS Board of Directors.Based on the results of the most recent randomized, controlled trials on EVT for basilar or vertebral artery occlusion, the expert panel agreed on the following recommendations. For patients presenting with an acute ischemic stroke due to an acute basilar or vertebral artery occlusion confirmed on CT angiography, National Institutes of Health Stroke Scale (NIHSS) score of ≥6, posterior circulation Alberta Stroke Program Early CT Score (PC-ASPECTS) ≥6, and age 18-89 years: (1) thrombectomy is indicated within 12 hours since last known well (class I, level B-R); (2) thrombectomy is reasonable within 12-24 hours from the last known well (class IIa, level B-R); (3) thrombectomy may be considered on a case by case basis for patients presenting beyond 24 hours since last known well (class IIb, level C-EO). In addition, thrombectomy may be considered on a case by case basis for patients aged <18 years or >89 years on a case by case basis (class IIb, level C-EO).The indications for EVT of ELVO strokes continue to expand and now include patients with basilar artery occlusion. Further prospective, randomized controlled trials are warranted to elucidate the efficacy and safety of EVT in populations not included in this set of recommendations, and to confirm long term outcomes.
View details for DOI 10.1136/jnis-2024-021705
View details for PubMedID 38670791
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CT Perfusion Derived rCBV < 42% Lesion Volume Is Independently Associated with Followup FLAIR Infarct Volume in Anterior Circulation Large Vessel Occlusion.
Diagnostics (Basel, Switzerland)
2024; 14 (8)
Abstract
Pretreatment CT Perfusion (CTP) parameter rCBV < 42% lesion volume has recently been shown to predict 90-day mRS. In this study, we aim to assess the relationship between rCBV < 42% and a radiographic follow-up infarct volume delineated on FLAIR images. In this retrospective evaluation of our prospectively collected database, we included acute stroke patients triaged by multimodal CT imaging, including CT angiography and perfusion imaging, with confirmed anterior circulation large vessel occlusion between 9 January 2017 and 10 January 2023. Follow-up FLAIR imaging was used to determine the final infarct volume. Student t, Mann-Whitney-U, and Chi-Square tests were used to assess differences. Spearman's rank correlation and linear regression analysis were used to assess associations between rCBV < 42% and follow-up infarct volume on FLAIR. In total, 158 patients (median age: 68 years, 52.5% female) met our inclusion criteria. rCBV < 42% (ρ = 0.56, p < 0.001) significantly correlated with follow-up-FLAIR infarct volume. On multivariable linear regression analysis, rCBV < 42% lesion volume (beta = 0.60, p < 0.001), ASPECTS (beta = -0.214, p < 0.01), mTICI (beta = -0.277, p < 0.001), and diabetes (beta = 0.16, p < 0.05) were independently associated with follow-up infarct volume. The rCBV < 42% lesion volume is independently associated with FLAIR follow-up infarct volume.
View details for DOI 10.3390/diagnostics14080845
View details for PubMedID 38667490
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Multicenter US clinical experience with the Scepter Mini balloon catheter.
Interventional neuroradiology : journal of peritherapeutic neuroradiology, surgical procedures and related neurosciences
2024: 15910199241246135
Abstract
Distal navigability and imprecise delivery of embolic agents are two limitations encountered during liquid embolization of cerebrospinal lesions. The dual-lumen Scepter Mini balloon (SMB) microcatheter was introduced to overcome these conventional microcatheters' limitations with few small single-center reports suggesting favorable results.A series of consecutive patients undergoing SMB-assisted endovascular embolization were extracted from prospectively maintained registries in seven North-American centers (November 2019 to September 2022).Fifty-four patients undergoing 55 embolization procedures utilizing SMB were included (median age 58.5; 48.1% females). Cranial dural arteriovenous fistula embolization was the most common indication (54.5%) followed by cranial arteriovenous malformation (27.3%). Staged/pre-operative embolization was done in 36.4% of cases; and 83.6% of procedures using Onyx-18. Most procedures utilized a transarterial approach (89.1%), and SMB-induced arterial-flow arrest concurrently with transvenous embolization was used in 10.9% of procedures. Femoral access/triaxial setups were utilized in the majority of procedures (65.5% and 60%, respectively). The median vessel diameter where the balloon was inflated of 1.8 mm, with a median of 1.5 cc of injected embolic material per procedure. Technical failures occurred in 5.5% of cases requiring aborting/replacement with other devices without clinical sequelae in any of the patients, with SMB-related procedural complications of 3.6% without clinical sequelae. Radiographic imaging follow-up was available in 76.9% of the patients (median follow-up 3.8 months), with complete occlusion (100%) or >50% occlusion in 92.5% of the cases, and unplanned retreatments in 1.8%.The SMB microcatheter is a useful new adjunctive device for balloon-assisted embolization of cerebrospinal lesions with a high technical success rate, favorable outcomes, and a reasonable safety profile.
View details for DOI 10.1177/15910199241246135
View details for PubMedID 38613371
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Percutaneous Disc Biopsy versus Bone Biopsy for the Identification of Infectious Agents in Osteomyelitis/Discitis.
Journal of vascular and interventional radiology : JVIR
2024
Abstract
To determine whether sampling of the disc or bone is more likely to yield positive tissue culture results in patients with vertebral discitis and osteomyelitis (VDO).Retrospective review was performed of consecutive patients who underwent vertebral disc or vertebral body biopsy at a single institution between February 2019 and May 2023. Inclusion criteria were age ≥18 years, presumed VDO on spinal magnetic resonance (MR) imaging, absence of paraspinal abscess, and technically successful percutaneous biopsy with fluoroscopic guidance. The primary outcome was a positive biopsy culture result, and secondary outcomes included complications such as nerve injury and segmental artery injury.Sixty-six patients met the inclusion criteria; 36 patients (55%) underwent disc biopsy, and 30 patients (45%) underwent bone biopsy. Six patients required a repeat biopsy for an initially negative culture result. No significant demographic, laboratory, antibiotic administration, or pain medication use differences were observed between the 2 groups. Patients who underwent bone biopsy were more likely to have a history of intravenous drug use (26.7%) compared with patients who underwent disc biopsy (5.5%; P = .017). Positive tissue culture results were observed in 41% of patients who underwent disc biopsy and 15% of patients who underwent bone biopsy (P = .016). No vessel or nerve injuries were detected after procedure in either group.Percutaneous disc biopsy is more likely to yield a positive tissue culture result than vertebral body biopsy in patients with VDO.
View details for DOI 10.1016/j.jvir.2024.02.016
View details for PubMedID 38613536
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Clinical Change During Inter-Hospital Transfer For Thrombectomy: Incidence, Associated Factors and Relationship With Outcome.
International journal of stroke : official journal of the International Stroke Society
2024: 17474930241246952
Abstract
Patients with acute ischemic stroke with a large vessel occlusion (LVO) admitted to non endovascular-capable centers often require inter-hospital transfer for thrombectomy. We aimed to describe the incidence of substantial clinical change during transfer, the factors associated with clinical change, and its relationship with 3-month outcome.We analyzed data from two cohorts of acute stroke patients transferred for thrombectomy to a comprehensive center (Stanford, USA, Nov 2019 to Jan 2023; Montpellier, France, Jan 2015 to Jan 2017), regardless of whether thrombectomy was eventually attempted. Patients were included if they had evidence of an LVO at the referring hospital and had an NIHSS score documented before and immediately after transfer. Inter-hospital clinical change was categorized as improvement (>=4 points and >=25% decrease between the NIHSS score in the referring hospital and upon comprehensive center arrival), deterioration (>=4 points and >=25% increase), or stability (neither improvement nor deterioration). The stable group was considered as the reference, and was compared to the improvement or deterioration groups separately.A total of 504 patients were included, of whom 22% experienced inter-hospital improvement, 14% deterioration, and 64% were stable. Pre-transfer variables independently associated with clinical improvement were intravenous thrombolysis use, more distal occlusions, and lower serum glucose; variables associated with deterioration included more proximal occlusions and higher serum glucose. On post-transfer imaging, clinical improvement was associated with arterial recanalization and smaller infarct growth; and deterioration with larger infarct growth. As compared to stable patients, those with clinical improvement had better 3-month functional outcome (adjusted cOR=2.43; 95%CI 1.59-3.71; P<0.001), while those with deterioration had worse outcome (adjusted cOR=0.60; 95%CI 0.37-0.98; P=0.044).Substantial inter-hospital clinical changes are frequently observed in LVO-related ischemic strokes, with significant impact on functional outcome. There is a need to develop treatments that improves the clinical status during transfer.
View details for DOI 10.1177/17474930241246952
View details for PubMedID 38576067
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CT perfusion based rCBF <38% volume is independently and negatively associated with digital subtraction angiography collateral score in anterior circulation large vessel occlusions.
The neuroradiology journal
2024: 19714009241242639
Abstract
BACKGROUND: Collateral status (CS) is an important biomarker of functional outcomes in patients with acute ischemic stroke secondary to large vessel occlusion (AIS-LVO). Pretreatment CT perfusion (CTP) parameters serve as reliable surrogates of collateral status (CS). In this study, we aim to assess the relationship between the relative cerebral blood flow less than 38% (rCBF <38%), with the reference standard American Society of Interventional and Therapeutic Neuroradiology (ASITN) collateral score (CS) on DSA.METHODS: In this prospectively collected, retrospectively reviewed analysis, inclusion criteria were as follows: (a) CT angiography (CTA) confirmed anterior circulation large vessel occlusion from 9/1/2017 to 10/01/2023; (b) diagnostic CT perfusion; and (c) underwent mechanical thrombectomy with documented ASITN CS. The ratios of the CTP-derived CBF values were calculated by dividing the values of the ischemic lesion by the corresponding values of the contralateral normal region (which were defined as rCBF). Spearman's rank correlation and logistic regression analysis were performed to determine the relationship of rCBF <38% lesion volume with DSA ASITN CS. p ≤ .05 was considered significant.RESULTS: In total, 223 patients [mean age: 67.77 ± 15.76 years, 56.1% (n = 125) female] met our inclusion criteria. Significant negative correlation was noted between rCBF <38% volume and DSA CS (rho = -0.37, p < .001). On multivariate logistic regression analysis, rCBF <38% volume was found to be independently associated with worse ASITN CS (unadjusted OR: 3.03, 95% CI: 1.60-5.69, p < .001, and adjusted OR: 2.73, 95% CI: 1.34-5.50, p < .01).CONCLUSION: Greater volume of tissue with rCBF <38% is independently associated with better DSA CS. rCBF <38% is a useful adjunct tool in collateralization-based prognostication. Future studies are needed to expand our understanding of the role of rCBF <38% within the decision-making in patients with AIS-LVO.
View details for DOI 10.1177/19714009241242639
View details for PubMedID 38528780
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Cerebral Venous Outflow in Acute Ischemic Stroke Patients - Out Through the Middle!
Academic radiology
2024
View details for DOI 10.1016/j.acra.2024.02.050
View details for PubMedID 38519300
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Follow-up infarct volume on fluid attenuated inversion recovery (FLAIR)imaging in distal medium vessel occlusions: the role of cerebral blood volume index.
Journal of neurology
2024
Abstract
BACKGROUND: Distal medium vessel occlusions (DMVOs) contribute substantially to the incidence of acute ischemic strokes (AIS) and pose distinct challenges in clinical management and prognosis. Neuroimaging techniques, such as Fluid Attenuation Inversion Recovery (FLAIR) imaging and cerebral blood volume (CBV) index derived from perfusion imaging, have significantly improved our ability to assess the impact of strokes and predict their outcomes. The primary objective of this study was to investigate relationship between follow-up infarct volume (FIV) as assessed by FLAIR imaging in patients with DMVOs.METHODS: This prospectively collected, retrospective reviewed cohort study included patients from two comprehensive stroke centers within the Johns Hopkins Medical Enterprise, spanning August 2018-October 2022. The cohort consisted of adults with AIS attributable to DMVO. Detailed imaging analyses were conducted, encompassing non-contrast CT, CT angiography (CTA), CT perfusion (CTP), and FLAIR imaging. Univariable and multivariable linear regression models were employed to assess the association between different factors and FIV.RESULTS: The study included 79 patients with DMVO stroke with a median age of 69years (IQR, 62-77years), and 57% (n=45) were female. There was a negative correlation between the CBV index and FIV in a univariable linear regression analysis (Beta=-16; 95% CI, -23 to -8.3; p<0.001) and a multivariable linear regression model (Beta=-9.1 per 0.1 change; 95% CI, -15 to -2.7; p=0.006). Diabetes was independently associated with larger FIV (Beta=46; 95% CI, 16 to 75; p=0.003). Additionally, a higher baseline ASPECTS was associated with lower FIV (Beta=-30; 95% CI, -41 to -20; p<0.001).CONCLUSION: Our findings underscore the CBV index as an independent association with FIV in DMVOs, which highlights the critical role of collateral circulation in determining stroke outcomes in this patient population. In addition, our study confirms a negative association of ASPECTS with FLAIR FIV and identifies diabetes as independent factor associated with larger FIV. These insights pave the way for further large-scale, prospective studies to corroborate these findings, thereby refining the strategies for stroke prognostication and management.
View details for DOI 10.1007/s00415-024-12279-3
View details for PubMedID 38507075
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Prolonged venous transit on perfusion imaging is associated with higher odds of mortality in successfully reperfused patients with large vessel occlusion stroke.
Journal of neurointerventional surgery
2024
Abstract
Poor venous outflow (VO) profiles are associated with unfavorable outcomes in patients with acute ischemic stroke caused by large vessel occlusion (AIS-LVO), despite achieving successful reperfusion. The objective of this study is to assess the association between mortality and prolonged venous transit (PVT), a novel visual qualitative VO marker on CT perfusion (CTP) time to maximum (Tmax) maps.We performed a retrospective analysis of prospectively collected data from consecutive adult patients with AIS-LVO with successful reperfusion (modified Thrombolysis in Cerebral Infarction 2b/2c/3). PVT+ was defined as Tmax ≥10 s timing on CTP Tmax maps in at least one of the following: superior sagittal sinus (proximal venous drainage) and/or torcula (deep venous drainage). PVT- was defined as lacking this in both regions. The primary outcome was mortality at 90 days. In a 1:1 propensity score-matched cohort, regressions were performed to determine the effect of PVT on 90-day mortality.In 127 patients of median (IQR) age 71 (64-81) years, mortality occurred in a significantly greater proportion of PVT+ patients than PVT- patients (32.5% vs 12.6%, P=0.01). This significant difference persisted after matching (P=0.03). PVT+ was associated with a significantly increased likelihood of 90-day mortality (OR 1.22 (95% CI 1.02 to 1.46), P=0.03) in the matched cohort.PVT+ was significantly associated with 90-day mortality despite successful reperfusion therapy in patients with AIS-LVO. PVT is a simple VO profile marker with potential as an adjunctive metric during acute evaluation of AIS-LVO patients. Future studies will expand our understanding of using PVT in the evaluation of patients with AIS-LVO.
View details for DOI 10.1136/jnis-2024-021488
View details for PubMedID 38471762
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The Relative Cerebral Blood Volume (rCBV) < 42% Is Independently Associated with Collateral Status in Anterior Circulation Large Vessel Occlusion.
Journal of clinical medicine
2024; 13 (6)
Abstract
Background: The pretreatment CT perfusion (CTP) marker the relative cerebral blood volume (rCBV) < 42% lesion volume has recently been shown to predict 90-day functional outcomes; however, studies assessing correlations of the rCBV < 42% lesion volume with other outcomes remain sparse. Here, we aim to assess the relationship between the rCBV < 42% lesion volume and the reference standard digital subtraction angiography (DSA)-derived American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN) collateral score, hereby referred as the DSA CS. Methods: In this retrospective evaluation of our prospectively collected database, we included acute stroke patients triaged by multimodal CT imaging, including CT angiography and perfusion imaging, with confirmed anterior circulation large vessel occlusion between 1 September 2017 and 1 October 2023. Group differences were assessed using the Student's t test, Mann-Whitney U test and Chi-Square test. Spearman's rank correlation and logistic regression analyses were used to assess associations between rCBV < 42% and DSA CS. Results: In total, 222 patients (median age: 69 years, 56.3% female) met our inclusion criteria. In the multivariable logistic regression analysis, taking into account age, sex, race, hypertension, hyperlipidemia, diabetes, atrial fibrillation, prior stroke or transient ischemic attack, the admission National Institute of Health stroke scale, the premorbid modified Rankin score, the Alberta stroke program early CT score (ASPECTS), and segment occlusion, the rCBV < 42% lesion volume (adjusted OR: 0.98, p < 0.05) was independently associated with the DSA CS. Conclusion: The rCBV < 42% lesion volume is independently associated with the DSA CS.
View details for DOI 10.3390/jcm13061588
View details for PubMedID 38541813
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Incidence and clinical outcomes of perforations during mechanical thrombectomy for medium vessel occlusion in acute ischemic stroke: A retrospective, multicenter, and multinational study.
European stroke journal
2024: 23969873231219412
Abstract
BACKGROUND: Mechanical thrombectomy (MT) has revolutionized the treatment of acute ischemic stroke (AIS) due to large vessel occlusion (LVO), but its efficacy and safety in medium vessel occlusion (MeVO) remain less explored. This multicenter, retrospective study aims to investigate the incidence and clinical outcomes of vessel perforations (confirmed by extravasation during an angiographic series) during MT for AIS caused by MeVO.METHODS: Data were collected from 37 academic centers across North America, Asia, and Europe between September 2017 and July 2021. A total of 1373 AIS patients with MeVO underwent MT. Baseline characteristics, procedural details, and clinical outcomes were analyzed.RESULTS: The incidence of vessel perforation was 4.8% (66/1373). Notably, our analysis indicates variations in perforation rates across different arterial segments: 8.9% in M3 segments, 4.3% in M2 segments, and 8.3% in A2 segments (p=0.612). Patients with perforation had significantly worse outcomes, with lower rates of favorable angiographic outcomes (TICI 2c-3: 23% vs 58.9%, p<0.001; TICI 2b-3: 56.5% vs 88.3%, p<0.001). Functional outcomes were also worse in the perforation group (mRS 0-1 at 3months: 22.7% vs 36.6%, p=0.031; mRS 0-2 at 3months: 28.8% vs 53.9%, p<0.001). Mortality was higher in the perforation group (30.3% vs 16.8%, p=0.008).CONCLUSION: This study reveals that while the occurrence of vessel perforation in MT for AIS due to MeVO is relatively rare, it is associated with poor functional outcomes and higher mortality. The findings highlight the need for increased caution and specialized training in performing MT for MeVO. Further prospective research is required for risk mitigation strategies.
View details for DOI 10.1177/23969873231219412
View details for PubMedID 38409796
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Factors Affecting Selection of TraineE for Neurointervention (FASTEN).
Interventional neuroradiology : journal of peritherapeutic neuroradiology, surgical procedures and related neurosciences
2024: 15910199241232726
Abstract
BACKGROUND AND IMPORTANCE: Neurointervention is a very competitive specialty in the United States due to the limited number of training spots and the larger pool of applicants. The training standards are continuously updated to ensure solid training experiences. Factors affecting candidate(s) selection have not been fully established yet. Our study aims to investigate the factors influencing the selection process.METHODS: A 52-question survey was distributed to 93 program directors (PDs). The survey consisted of six categories: (a) Program characteristics, (b) Candidate demographics, (c) Educational credentials, (d) Personal traits, (e) Research and extracurricular activities, and (f) Overall final set of characteristics. The response rate was 59.1%. As per the programs' characteristics, neurosurgery was the most involved specialty in running the training programs (69%). Regarding demographics, the need for visa sponsorship held the greatest prominence with a mean score of 5.9 [standard deviation (SD) 2.9]. For the educational credentials, being a graduate from a neurosurgical residency and the institution where the candidate's residency training is/was scored the highest [5.4 (SD=2.9), 5.4 (SD=2.5), respectively]. Regarding the personal traits, assessment by faculty members achieved the highest score [8.9 (SD=1)]. In terms of research/extracurricular activities, fluency in English had the highest score [7.2 (SD=1.9)] followed by peer-reviewed/PubMed-indexed publications [6.4 (SD=2.2)].CONCLUSION: Our survey investigated the factors influencing the final decision when choosing the future neurointerventional trainee, including demographic, educational, research, and extracurricular activities, which might serve as valuable guidance for both applicants and programs to refine the selection process.
View details for DOI 10.1177/15910199241232726
View details for PubMedID 38389309
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Treatment of Cerebral Vasospasm Following Aneurysmal Subarachnoid Hemorrhage using the Neurospeed Semi-compliant Balloon.
Clinical neuroradiology
2024
Abstract
BACKGROUND AND PURPOSE: Cerebral vasospasm (CV) following aneurysmal subarachnoid hemorrhage (aSAH) may lead to morbidity and mortality. Endovascular mechanical angioplasty may be performed if symptomatic CV is refractory to noninvasive medical management. Off-label compliant remodelling balloons tend to conform to the course of the vessel, contrary to noncompliant or semi-compliant balloons. Our objective is to describe our initial experience with the semi-compliant Neurospeed balloon (approved for intracranial stenosis) in cerebral vasospasm treatment following aSAH.METHODS: All patients included in the prospective observational SAVEBRAIN PWI (NCT05276934 on clinicaltrial.gov) study who underwent cerebral angioplasty using the Neurospeed balloon for the treatment of medically refractory and symptomatic CV after aSAH were identified. Patient demographic information, procedural details and outcomes were obtained from electronic medical records.RESULTS: Between February 2022 and June 2023, 8consecutive patients underwent CV treatment with the Neurospeed balloon. Angioplasty of 48arterial segments (supraclinoid internal carotid artery, A1and A2segments of the anterior cerebral artery, M1and M2segments of the middle cerebral artery) was attempted and 44/48 (92%) were performed. The vessel diameter significantly improved following angioplasty (+81%), while brain hypoperfusion decreased (-81% of the mean TMax). There was no long-term clinical complication, 4% periprocedural complications occurred.CONCLUSION: The semi-compliant Neurospeed balloon is effective in the treatment of cerebral vasospasm following aSAH, bringing anew device into the armamentarium of the neurointerventionalist to perform intracranial angioplasty.
View details for DOI 10.1007/s00062-024-01390-7
View details for PubMedID 38386051
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Use of the pRESET LITE thrombectomy device in combined approach for medium vessel occlusions: A multicenter evaluation.
Neuroradiology
2024
Abstract
PURPOSE: Our purpose was to assess the efficacy and safety of the pRESET LITE stent retriever (Phenox, Bochum, Germany), designed for medium vessel occlusion (MeVO) in acute ischemic stroke (AIS) patients with a primary MeVO.METHODS: We performed a retrospective analysis of the MAD MT Consortium, an integration of prospectively maintained databases at 37 academic institutions in Europe, North America, and Asia, of AIS patients who underwent mechanical thrombectomy with the pRESET LITE stent retriever for a primary MeVO. We subcategorized occlusions into proximal MeVOs (segments A1, M2, and P1) vs. distal MeVOs/DMVO (segments A2, M3-M4, and P2). We reviewed patient and procedural characteristics, as well as angiographic and clinical outcomes.RESULTS: Between September 2016 and December 2021, 227 patients were included (50% female, median age 78 [65-84] years), of whom 161 (71%) suffered proximal MeVO and 66 (29%) distal MeVO. Using a combined approach in 96% of cases, successful reperfusion of the target vessel (mTICI 2b/2c/3) was attained in 85% of proximal MeVO and 97% of DMVO, with a median of 2 passes (IQR: 1-3) overall. Periprocedural complications rate was 7%. Control CT at day 1 post-MT revealed a hemorrhagic transformation in 63 (39%) patients with proximal MeVO and 24 (36%) patients with DMVO, with ECASS-PH type hemorrhagic transformations occurring in 3 (1%) patients. After 3months, 58% of all MeVO and 63% of DMVO patients demonstrated a favorable outcome (mRS 0-2).CONCLUSION: Mechanical thrombectomy using the pRESET LITE in a combined approach with an aspiration catheter appears effective for primary medium vessel occlusions across several centers and physicians.
View details for DOI 10.1007/s00234-024-03302-5
View details for PubMedID 38381145
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A Clinical and Imaging Fused Deep Learning Model Matches Expert Clinician Prediction of 90-Day Stroke Outcomes.
AJNR. American journal of neuroradiology
2024
Abstract
Predicting long-term clinical outcome in acute ischemic stroke is beneficial for prognosis, clinical trial design, resource management, and patient expectations. This study used a deep learning-based predictive model (DLPD) to predict 90-day mRS outcomes and compared its predictions with those made by physicians.A previously developed DLPD that incorporated DWI and clinical data from the acute period was used to predict 90-day mRS outcomes in 80 consecutive patients with acute ischemic stroke from a single-center registry. We assessed the predictions of the model alongside those of 5 physicians (2 stroke neurologists and 3 neuroradiologists provided with the same imaging and clinical information). The primary analysis was the agreement between the ordinal mRS predictions of the model or physician and the ground truth using the Gwet Agreement Coefficient. We also evaluated the ability to identify unfavorable outcomes (mRS >2) using the area under the curve, sensitivity, and specificity. Noninferiority analyses were undertaken using limits of 0.1 for the Gwet Agreement Coefficient and 0.05 for the area under the curve analysis. The accuracy of prediction was also assessed using the mean absolute error for prediction, percentage of predictions ±1 categories away from the ground truth (±1 accuracy [ACC]), and percentage of exact predictions (ACC).To predict the specific mRS score, the DLPD yielded a Gwet Agreement Coefficient score of 0.79 (95% CI, 0.71-0.86), surpassing the physicians' score of 0.76 (95% CI, 0.67-0.84), and was noninferior to the readers (P < .001). For identifying unfavorable outcome, the model achieved an area under the curve of 0.81 (95% CI, 0.72-0.89), again noninferior to the readers' area under the curve of 0.79 (95% CI, 0.69-0.87) (P < .005). The mean absolute error, ±1ACC, and ACC were 0.89, 81%, and 36% for the DLPD.A deep learning method using acute clinical and imaging data for long-term functional outcome prediction in patients with acute ischemic stroke, the DLPD, was noninferior to that of clinical readers.
View details for DOI 10.3174/ajnr.A8140
View details for PubMedID 38331959
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Association between occlusion location, net water uptake and ischemic lesion growth in large vessel anterior circulation strokes.
Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism
2024: 271678X241232193
Abstract
Ischemic lesion net water uptake (NWU) represents a quantitative imaging biomarker for cerebral edema in acute ischemic stroke. Data on NWU for distinct occlusion locations remain scarce, but might help to improve the prognostic value of NWU. In this retrospective multicenter cohort study, we compared NWU between patients with proximal large vessel occlusion (pLVO; ICA or proximal M1) and distal large vessel occlusion (dLVO; distal M1 or M2). NWU was quantified by densitometric measurements of the early ischemic region. Arterial collateral status was assessed using the Maas scale. Regression analysis was used to investigate the relationship between occlusion location, NWU and ischemic lesion growth. A total of 685 patients met inclusion criteria. Early ischemic lesion NWU was higher in patients with pLVO compared with dLVO (7.7% vs 3.9%, P < .001). The relationship between occlusion location and NWU was partially mediated by arterial collateral status. NWU was associated with absolute ischemic lesion growth between admission and follow-up imaging (β estimate, 5.50, 95% CI, 3.81-7.19, P < .001). This study establishes a framework for the relationship between occlusion location, arterial collateral status, early ischemic lesion NWU and ischemic lesion growth. Future prognostic thresholds for NWU might be optimized by adjusting for the occlusion location.
View details for DOI 10.1177/0271678X241232193
View details for PubMedID 38329032
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Random expert sampling for deep learning segmentation of acute ischemic stroke on non-contrast CT.
Journal of neurointerventional surgery
2024
Abstract
Outlining acutely infarcted tissue on non-contrast CT is a challenging task for which human inter-reader agreement is limited. We explored two different methods for training a supervised deep learning algorithm: one that used a segmentation defined by majority vote among experts and another that trained randomly on separate individual expert segmentations.The data set consisted of 260 non-contrast CT studies in 233 patients with acute ischemic stroke recruited from the multicenter DEFUSE 3 (Endovascular Therapy Following Imaging Evaluation for Ischemic Stroke 3) trial. Additional external validation was performed using 33 patients with matched stroke onset times from the University Hospital Lausanne. A benchmark U-Net was trained on the reference annotations of three experienced neuroradiologists to segment ischemic brain tissue using majority vote and random expert sampling training schemes. The median of volume, overlap, and distance segmentation metrics were determined for agreement in lesion segmentations between (1) three experts, (2) the majority model and each expert, and (3) the random model and each expert. The two sided Wilcoxon signed rank test was used to compare performances (1) to 2) and (1) to (3). We further compared volumes with the 24 hour follow-up diffusion weighted imaging (DWI, final infarct core) and correlations with clinical outcome (modified Rankin Scale (mRS) at 90 days) with the Spearman method.The random model outperformed the inter-expert agreement ((1) to (2)) and the majority model ((1) to (3)) (dice 0.51±0.04 vs 0.36±0.05 (P<0.0001) vs 0.45±0.05 (P<0.0001)). The random model predicted volume correlated with clinical outcome (0.19, P<0.05), whereas the median expert volume and majority model volume did not. There was no significant difference when comparing the volume correlations between random model, median expert volume, and majority model to 24 hour follow-up DWI volume (P>0.05, n=51).The random model for ischemic injury delineation on non-contrast CT surpassed the inter-expert agreement ((1) to (2)) and the performance of the majority model ((1) to (3)). We showed that the random model volumetric measures of the model were consistent with 24 hour follow-up DWI.
View details for DOI 10.1136/jnis-2023-021283
View details for PubMedID 38302420
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Perfusion Profiles May Differ Between Asymptomatic Versus Symptomatic Internal Carotid Artery Occlusion.
Journal of stroke
2024; 26 (1): 108-111
View details for DOI 10.5853/jos.2023.02768
View details for PubMedID 38326709
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Robust Collaterals Are Independently Associated With Excellent Recanalization in Patients With Large Vessel Occlusion Causing Acute Ischemic Stroke
STROKE-VASCULAR AND INTERVENTIONAL NEUROLOGY
2024; 4 (1)
View details for DOI 10.1161/SVIN.123.001141
View details for Web of Science ID 001160115800013
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Pretreatment CTP Collateral Parameters Predict Good Outcomes in Successfully Recanalized Middle Cerebral Artery Distal Medium Vessel Occlusions.
Clinical neuroradiology
2023
Abstract
Distal medium vessel occlusions (DMVOs) account for a large percentage of vessel occlusions resulting in acute ischemic stroke (AIS) with disabling symptoms. We aim to assess whether pretreatment quantitative CTP collateral status (CS) parameters can serve as imaging biomarkers for good clinical outcomes prediction in successfully recanalized middle cerebral artery (MCA) DMVOs.We performed a retrospective analysis of consecutive patients with AIS secondary to primary MCA-DMVOs who were successfully recanalized by mechanical thrombectomy (MT) defined as modified thrombolysis in cerebral infarction (mTICI) 2b, 2c, or 3. We evaluated the association between the CBV index and HIR independently with good clinical outcomes (modified Rankin score 0-2) using Spearman rank correlation, logistic regression, and ROC analyses.From 22 August 2018 to 18 October 2022 8/22/2018 to 10/18/2022, 60 consecutive patients met our inclusion criteria (mean age 71.2 ± 13.9 years old [mean ± SD], 35 female). The CBV index (r = -0.693, p < 0.001) and HIR (0.687, p < 0.001) strongly correlated with 90-day mRS. A CBV index ≥ 0.7 (odds ratio, OR, 2.27, range 6.94-21.23 [OR] 2.27 [6.94-21.23], p = 0.001)) and lower likelihood of prior stroke (0.13 [0.33-0.86]), p = 0.024)) were independently associated with good outcomes. The ROC analysis demonstrated good performance of the CBV index in predicting good 90-day mRS (AUC 0.73, p = 0.003) with a threshold of 0.7 for optimal sensitivity (71% [52.0-85.8%]) and specificity (76% [54.9-90.6%]). The HIR also demonstrated adequate performance in predicting good 90-day mRS (AUC 0.77, p = 0.001) with a threshold of 0.3 for optimal sensitivity (64.5% [45.4-80.8%]) and specificity (76.0% [54.9-90.6%]).A CBV index ≥ 0.7 may be independently associated with good clinical outcomes in our cohort of AIS caused by MCA-DMVOs that were successfully treated with MT. Furthermore, a HIR < 0.3 is also associated with good clinical outcomes. This is the first study of which we are aware to identify a CBV index threshold for MCA-DMVOs.
View details for DOI 10.1007/s00062-023-01371-2
View details for PubMedID 38155255
View details for PubMedCentralID 7668337
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RAPID aneurysm accurately measures aneurysm size on CT angiography compared to three-dimensional digital subtraction angiography.
Interventional neuroradiology : journal of peritherapeutic neuroradiology, surgical procedures and related neurosciences
2023: 15910199231222676
Abstract
Cerebral aneurysms are often identified and characterized on non-invasive CT Angiography (CTA) images, but digital subtraction angiography (DSA) is the gold standard for aneurysm evaluation.We compared cerebral aneurysm size measurements as measured from CTA processed by a semi-automated artificial intelligence software program (RAPID Aneurysm) and three-dimensional rotational DSA (3D-DSA).We performed a retrospective cohort study of consecutive patients with a cerebral aneurysm who underwent CTA and DSA with 3D reformations. CTA images were processed by RAPID Aneurysm to determine aneurysm height, width, and neck width. The reference standard was aneurysm measurements on 3D-DSA as measured by two neurointerventionalists. Both readers were blinded to RAPID Aneurysm measurements. Correlation and bias between these measurements were determined.Results from 50 patients with 50 aneurysms were compared. 32 patients (64%) were female. Median age was 65 (IQR: 56.25-71.75). 37 patients (74%) presented with ruptured aneurysms. The aneurysms represented a range of aneurysm sizes (1.9-33.3 mm; IQR 3.6-7.2 mm). RAPID Aneurysm size measurements showed excellent correlation and low bias (correlation, mean difference) when compared to the reference standard for aneurysm height (0.98, -0.9 mm), width (0.98, 0.1 mm), and neck width (0.94, 1.1 mm). The inter-reader comparison between the two neurointerventionalists was similarly excellent for aneurysm height (0.97, -0.4 mm), width (0.98, -0.2 mm), and neck width (0.89, 0.8 mm).RAPID Aneurysm measurement of cerebral aneurysm height, width, and neck width on CTA is strongly correlated to expert neurointerventionalist measurements on 3D-DSA.
View details for DOI 10.1177/15910199231222676
View details for PubMedID 38150662
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Redefining CT perfusion-based ischemic core estimates for the ghost core in early time window stroke.
Journal of neuroimaging : official journal of the American Society of Neuroimaging
2023
Abstract
In large vessel occlusion (LVO) stroke patients, relative cerebral blood flow (rCBF)<30% volume thresholds are commonly used in treatment decisions. In the early time window, nearly infarcted but salvageable tissue volumes may lead to pretreatment overestimates of infarct volume, and thus potentially exclude patients who may otherwise benefit from intervention. Our multisite analysis aims to explore the strength of relationships between widely used pretreatment CT parameters and clinical outcomes for early window stroke patients.Patients from two sites in a prospective registry were analyzed. Patients with LVOs, presenting within 3 hours of last known well, and who were successfully reperfused were included. Primary short-term neurological outcome was percent National Institutes of Health Stroke Scale (NIHSS) change from admission to discharge. Secondary long-term outcome was 90-day modified Rankin score. Spearman's correlations were performed. Significance was attributed to p-value⩽.05.Among 73 patients, median age was 66 (interquartile range 54-76) years. Among all pretreatment imaging parameters, rCBF<30%, rCBF<34%, and rCBF<38% volumes were significantly, inversely correlated with percentage NIHSS change (p<.048). No other parameters significantly correlated with outcomes.Our multisite analysis shows that favorable short-term neurological recovery was significantly correlated with rCBF volumes in the early time window. However, modest strength of correlations provides supportive evidence that the applicability of general ischemic core estimate thresholds in this subpopulation is limited. Our results support future larger-scale efforts to liberalize or reevaluate current rCBF parameter thresholds guiding treatment decisions for early time window stroke patients.
View details for DOI 10.1111/jon.13180
View details for PubMedID 38146065
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Pretreatment parameters associated with hemorrhagic transformation among successfully recanalized medium vessel occlusions.
Journal of neurology
2023
Abstract
Although pretreatment radiographic biomarkers are well established for hemorrhagic transformation (HT) following successful mechanical thrombectomy (MT) in large vessel occlusion (LVO) strokes, they are yet to be explored for medium vessel occlusion (MeVO) acute ischemic strokes. We aim to investigate pretreatment imaging biomarkers representative of collateral status, namely the hypoperfusion intensity ratio (HIR) and cerebral blood volume (CBV) index, and their association with HT in successfully recanalized MeVOs. A prospectively collected registry of acute ischemic stroke patients with MeVOs successfully recanalized with MT between 2019 and 2023 was retrospectively reviewed. A multivariate logistic regression for HT of any subtype was derived by combining significant univariate predictors into a forward stepwise regression with minimization of Akaike information criterion. Of 60 MeVO patients successfully recanalized with MT, HT occurred in 28.3% of patients. Independent factors for HT included: diabetes mellitus history (p=0.0005), CBV index (p=0.0071), and proximal versus distal occlusion location (p=0.0062). A multivariate model with these factors had strong diagnostic performance for predicting HT (area under curve [AUC] 0.93, p<0.001). Lower CBV indexes, distal occlusion location, and diabetes history are significantly associated with HT in MeVOs successfully recanalized with MT. Of note, HIR was not found to be significantly associated with HT.
View details for DOI 10.1007/s00415-023-12149-4
View details for PubMedID 38099953
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Early neurological deterioration in patients with acute ischemic stroke is linked to unfavorable cerebral venous outflow.
European stroke journal
2023: 23969873231208277
Abstract
Early neurological deterioration (END) is associated with poor outcomes in patients with acute ischemic stroke due to large vessel occlusion (AIS-LVO). Causes of END after mechanical thrombectomy (MT) include unsuccessful recanalization and reperfusion hemorrhages. However, little is known about END excluding the aforementioned causes. We aimed to investigate factors associated with unexplained END (ENDunexplained) with regard to the cerebral collateral status.Multicenter retrospective study of AIS-LVO patients with successful MT (mTICI 2b-3). On admission CT angiography (CTA), pial arterial collaterals and venous outflow (VO) were assessed using the modified Tan-Scale and the Cortical Vein Opacification Score (COVES), respectively. ENDunexplained was defined as an increase in NIHSS score of ⩾ 4 within the first 24 hours after MT without parenchymal hemorrhage on follow-up imaging. Multivariable regression analyses were performed to examine factors of ENDunexplained and unfavorable functional outcome (modified Rankin Scale score 3-6).A total of 620 patients met the inclusion criteria. ENDunexplained occurred in 10% of patients. While there was no significant difference in pial arterial collaterals, patients with ENDunexplained exhibited more often unfavorable VO (81% vs. 53%; P < 0.001). Unfavorable VO (aOR [95% CI]; 2.56 [1.02-6.40]; P = 0.045) was an independent predictor of ENDunexplained. ENDunexplained was independently associated with unfavorable functional outcomes at 90 days (aOR [95% CI]; 6.25 [2.06-18.94]; P = 0.001).Unfavorable VO on admission CTA was associated with ENDunexplained. ENDunexplained was independently linked to unfavorable functional outcomes at 90 days. Identifying AIS-LVO patients at risk of ENDunexplained may help to select patients for intensified monitoring and guide to optimal treatment regimes.
View details for DOI 10.1177/23969873231208277
View details for PubMedID 38069665
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Pretreatment CT perfusion collateral parameters correlate with penumbra salvage in middle cerebral artery occlusion.
Journal of neuroimaging : official journal of the American Society of Neuroimaging
2023
Abstract
BACKGROUND AND PURPOSE: Acute ischemic stroke due to large vessel occlusion (AIS-LVO) is a major cause of functional dependence. Collateral status (CS) is an important determinant of functional outcomes. Pretreatment CT perfusion (CTP) parameters serve as reliable surrogates of CS. Penumbra Salvage Index (PSI) is another parameter predictive of functional outcomes in AIS-LVO. The aim of this study is to assess the relationship of pretreatment CTP parameters with PSI.METHODS: In this prospectively collected, retrospectively reviewed multicenter analysis, inclusion criteria were as follows: (1) CT angiography confirmed middle cerebral artery (MCA) M1-segment and proximal M2-segment occlusion from 9/1/2017 to 9/22/2022; (2) diagnostic CTP; and (3) available diagnostic Magnetic resonance Imaging (MRI) diffusion-weighted images. Pearson correlation analysis was performed to assess the association between cerebral blood volume (CBV) index and hypoperfusion intensity ratio (HIR) with PSI. p value ≤.05 was considered statistically significant.RESULTS: In total, 131 patients (n = 86, M1 and n = 45, proximal M2 occlusion) met our inclusion criteria. CBV index showed a modest positive correlation with PSI (r = 0.34, p<.001) in patients with proximal MCA occlusion. Similar trends were noted in subgroup analysis of patients with M1 occlusion, and proximal M2 occlusion. Whereas, HIR did not have a strong trend or correlation with PSI.CONCLUSION: CBV index correlates with PSI, whereas HIR does not. Future studies are needed to expand our understanding of the adjunct role of CBV index with other similar pretreatment CTP-based markers in clinical evaluation and decision-making in patients with MCA occlusion.
View details for DOI 10.1111/jon.13178
View details for PubMedID 38057941
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Excellent Recanalization and Small Core Volumes Are Associated With Favorable AM-PAC Score in Patients With Acute Ischemic Stroke Secondary to Large Vessel Occlusion.
Archives of rehabilitation research and clinical translation
2023; 5 (4): 100306
Abstract
Objective: To assess pretreatment and interventional parameters as predictors of favorable Activity Measure for Post-Acute Care (AM-PAC) scores for optimal discharge planning.Design: In this prospectively collected, retrospectively reviewed multicenter study from 9/1/2017 to 9/22/2022, patients were dichotomized into favorable and unfavorable AM-PAC. Multivariate logistic regression and receiver operator characteristics analyses were performed for the identified significant variables. A P value of ≤.05 was significant.Setting: Hospitalized care.Participants: In total, 229 patients (mean ±SD 70.65 ±15.2 [55.9% women]) met our inclusion criteria. Inclusion criteria were (a) computed tomography (CT) angiography confirmed LVO from 9/1/2017 to 9/22/2022; (b) diagnostic CT perfusion; and (c) available AM-PAC scores.Interventions: None.Main Outcome Measures: Favorable AM-PAC, defined as a daily activity score ≥19 and basic mobility score of ≥17.Results: Patients with favorable AM-PAC were younger (61.3 vs 70.7, P<.001), had lower admission glucose (mean, 124 vs 136, P=.042), lower blood urea nitrogen (mean, 15.59 vs 19.11, P<.001), and lower admission National Institutes of Health Stroke Scale (NIHSS) (mean, 10.58 vs 16.15, P<.001). No differences in sex were noted. Multivariate regression analyses revealed age, admission NIHSS, relative cerebral blood flow (rCBF) <30% volume, and modified thrombolysis in cerebral infarction (mTICI) score to be independent predictors of favorable AM-PAC (P<.047 for all predictors). The combined model revealed an area under the curve (AUC) of 0.83 (IQR 0.75-0.86).Conclusion: Excellent recanalization, smaller core volumes, younger age, and lower stroke severity independently predict favorable outcomes as measured by AM-PAC.
View details for DOI 10.1016/j.arrct.2023.100306
View details for PubMedID 38163017
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The Compensation Index Is Better Associated with DSA ASITN Collateral Score Compared to the Cerebral Blood Volume Index and Hypoperfusion Intensity Ratio.
Journal of clinical medicine
2023; 12 (23)
Abstract
Pretreatment CT Perfusion (CTP) parameters serve as reliable surrogates of collateral status (CS). In this study, we aim to assess the relationship between the novel compensation index (CI, Tmax > 4 s/Tmax > 6 s) and already established CTP collateral markers, namely cerebral blood volume (CBV) index and Hypoperfusion Intensity Ratio (HIR), with the reference standard American Society of Interventional and Therapeutic Neuroradiology (ASITN) collateral score (CS) on DSA.In this retrospective study, inclusion criteria were the following: (a) CT angiography confirmed anterior circulation large vessel occlusion from 9 January 2017 to 10 January 2023; (b) diagnostic CT perfusion; and (c) underwent mechanical thrombectomy with documented DSA-CS. Student t-test, Mann-Whitney-U-test and Chi-square test were used to assess differences. Spearman's rank correlation and logistic regression analysis were used to assess associations. p ≤ 0.05 was considered significant.In total, 223 patients (mean age: 67.8 ± 15.8, 56% female) met our inclusion criteria. The CI (ρ = 0.37, p < 0.001) and HIR (ρ = -0.29, p < 0.001) significantly correlated with DSA-CS. Whereas the CBV Index (ρ = 0.1, p > 0.05) did not correlate with DSA-CS. On multivariate logistic regression analysis taking into account age, sex, ASPECTS, tPA, premorbid mRS, NIH stroke scale, prior history of TIA, stroke, atrial fibrillation, diabetes mellitus, hyperlipidemia, heart disease and hypertension, only CI was not found to be independently associated with DSA-CS (adjusted OR = 1.387, 95% CI: 1.09-1.77, p < 0.01).CI demonstrates a stronger correlation with DSA-CS compared to both the HIR and CBV Index where it may show promise as an additional quantitative pretreatment CS biomarker.
View details for DOI 10.3390/jcm12237365
View details for PubMedID 38068416
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Performance of RAPID noncontrast CT stroke platform in large vessel occlusion and intracranial hemorrhage detection.
Frontiers in neurology
2023; 14: 1324088
Abstract
Noncontrast CT (NCCT) is used to evaluate for intracerebral hemorrhage (ICH) and ischemia in acute ischemic stroke (AIS). Large vessel occlusions (LVOs) are a major cause of AIS, but challenging to detect on NCCT.The purpose of this study is to evaluate an AI software called RAPID NCCT Stroke (RAPID, iSchemaView, Menlo Park, CA) for ICH and LVO detection compared to expert readers.In this IRB approved retrospective, multicenter study, stand-alone performance of the software was assessed based on the consensus of 3 neuroradiologists and sensitivity and specificity were determined. The platform's performance was then compared to interpretation by readers comprised of eight general radiologists (GR) and three neuroradiologists (NR) in detecting ICH and hyperdense vessel sign (HVS) indicating LVO.A total of 244 cases were included. Of the 244, 115 were LVOs and 26 were ICHs. One hundred three cases did not have LVO nor ICH. Stand-alone performance of the software demonstrated sensitivities and specificities of 96.2 and 99.5% for ICH and 63.5 and 95.1% for LVO detection. Compared to all 11 readers and eight GR readers only respectively, the software demonstrated superiority, achieving significantly higher sensitivities (63.5% versus 43.6%, p < 0.0001 and 63.5% versus 40.9%, p = 0.001).The RAPID NCCT Stroke platform demonstrates superior performance to radiologists for detecting LVO from a NCCT. Use of this software platform could lead to earlier LVO detection and expedited transfer of these patients to a thrombectomy capable center.
View details for DOI 10.3389/fneur.2023.1324088
View details for PubMedID 38156093
View details for PubMedCentralID PMC10753184
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Priorities for Advancements in Neuroimaging in the Diagnostic Workup of Acute Stroke.
Stroke
2023
Abstract
STAIR XII (12th Stroke Treatment Academy Industry Roundtable) included a workshop to discuss the priorities for advancements in neuroimaging in the diagnostic workup of acute ischemic stroke. The workshop brought together representatives from academia, industry, and government. The participants identified 10 critical areas of priority for the advancement of acute stroke imaging. These include enhancing imaging capabilities at primary and comprehensive stroke centers, refining the analysis and characterization of clots, establishing imaging criteria that can predict the response to reperfusion, optimizing the Thrombolysis in Cerebral Infarction scale, predicting first-pass reperfusion outcomes, improving imaging techniques post-reperfusion therapy, detecting early ischemia on noncontrast computed tomography, enhancing cone beam computed tomography, advancing mobile stroke units, and leveraging high-resolution vessel wall imaging to gain deeper insights into pathology. Imaging in acute ischemic stroke treatment has advanced significantly, but important challenges remain that need to be addressed. A combined effort from academic investigators, industry, and regulators is needed to improve imaging technologies and, ultimately, patient outcomes.
View details for DOI 10.1161/STROKEAHA.123.044985
View details for PubMedID 37942645
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Brain edema growth after thrombectomy is associated with comprehensive collateral blood flow.
Journal of neurointerventional surgery
2023
Abstract
We determined whether a comprehensive assessment of cerebral collateral blood flow is associated with ischemic lesion edema growth in patients successfully treated by thrombectomy.This was a multicenter retrospective study of ischemic stroke patients who underwent thrombectomy treatment of large vessel occlusions. Collateral status was determined using the cerebral collateral cascade (CCC) model, which comprises three components: arterial collaterals (Tan Scale) and venous outflow profiles (Cortical Vein Opacification Score) on CT angiography, and tissue-level collaterals (hypoperfusion intensity ratio) on CT perfusion. Quantitative ischemic lesion net water uptake (NWU) was used to determine edema growth between admission and follow-up non-contrast head CT (ΔNWU). Three groups were defined: CCC+ (good pial collaterals, tissue-level collaterals, and venous outflow), CCC- (poor pial collaterals, tissue-level collaterals, and venous outflow), and CCCmixed (remainder of patients). Primary outcome was ischemic lesion edema growth (ΔNWU). Multivariable regression models were used to assess the primary and secondary outcomes.538 patients were included. 157 patients had CCC+, 274 patients CCCmixed, and 107 patients CCC- profiles. Multivariable regression analysis showed that compared with patients with CCC+ profiles, CCC- (β 1.99, 95% CI 0.68 to 3.30, P=0.003) and CCC mixed (β 1.65, 95% CI 0.75 to 2.56, P<0.001) profiles were associated with greater ischemic lesion edema growth (ΔNWU) after successful thrombectomy treatment. ΔNWU (OR 0.74, 95% CI 0.68 to 0.8, P<0.001) and CCC+ (OR 13.39, 95% CI 4.88 to 36.76, P<0.001) were independently associated with functional independence.A comprehensive assessment of cerebral collaterals using the CCC model is strongly associated with edema growth and functional independence in acute stroke patients successfully treated by endovascular thrombectomy.
View details for DOI 10.1136/jnis-2023-020921
View details for PubMedID 37918909
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Aspiration Versus Stent-Retriever as First-Line Endovascular Therapy Technique for Primary Medium and Distal Intracranial Occlusions: A Propensity-Score Matched Multicenter Analysis
STROKE-VASCULAR AND INTERVENTIONAL NEUROLOGY
2023; 3 (6)
View details for DOI 10.1161/SVIN.123.000931
View details for Web of Science ID 001178890300001
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Semiautomated Detection of Early Infarct Signs on Noncontrast CT Improves Interrater Agreement.
Stroke
2023
Abstract
BACKGROUND: Acute ischemic infarct identification on noncontrast computed tomography (NCCT) is highly variable between raters. A semiautomated method for segmentation of acute ischemic lesions on NCCT may improve interrater reliability.METHODS: Patients with successful endovascular reperfusion from the DEFUSE 3 trial (Endovascular Therapy Following Imaging Evaluation for Ischemic Stroke) were included. We created relative NCCT (rNCCT) color-gradient overlays by comparing the density of a voxel on NCCT to the homologous region in the contralateral hemisphere. Regions with a relative hypodensity of at least 5% were visualized. We coregistered baseline and follow-up images. Two neuroradiologists and 6 nonradiologists segmented the acute ischemic lesion on the baseline scans with 2 methods: (1) manually outlining hypodense regions on the NCCT (unassisted segmentation) and (2) manually excluding areas deemed outside of the ischemic lesion on the rNCCT color map (rNCCT-assisted segmentation). Voxelwise interrater agreement was quantified using the Dice similarity coefficient and volumetric agreement between raters with the detection index (DI), defined as the true positive volume minus the false positive volume.RESULTS: From a total of 92, we included 61 patients. Median age was 59 (64-77), and 57% were female. Stroke onset was known in 39%. Onset to NCCT was median, 8.5 hours (7-11) and median 10 hours (8.4-11.5) in patients with known and unknown onset, respectively. Compared with unassisted NCCT segmentation, rNCCT-assisted segmentation increased the Dice similarity coefficient by >50% for neuroradiologists (Dice similarity coefficient, 0.38 versus 0.83; P<0.001) and nonradiologists (Dice similarity coefficient, 0.14 versus 0.84; P<0.001), and improved the DI among nonradiologists (mean improvement, 5.8 mL [95% CI, 3.1-8.5] mL, P<0.001) but not among neuroradiologists.CONCLUSIONS: The high variability of manual segmentations of the acute ischemic lesion on NCCT is greatly reduced using semiautomated rNCCT. The rNCCT map may therefore aid acute infarct detection and provide more reliable infarct estimates for clinicians with less experience.
View details for DOI 10.1161/STROKEAHA.123.044058
View details for PubMedID 37909206
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First pass effect as an independent predictor of functional outcomes in medium vessel occlusions: An analysis of an international multicenter study.
European stroke journal
2023: 23969873231208276
Abstract
INTRODUCTION: First pass effect (FPE), achievement of complete recanalization (mTICI 2c/3) with a single pass, is a significant predictor of favorable outcomes for endovascular treatment (EVT) in large vessel occlusion stroke (LVO). However, data concerning the impact on functional outcomes and predictors of FPE in medium vessel occlusions (MeVO) are scarce.PATIENTS AND METHODS: We conducted an international retrospective study on MeVO cases. Multivariable logistic modeling was used to establish independent predictors of FPE. Clinical and safety outcomes were compared between the two study groups (FPE vs non-FPE) using logistic regression models. Good outcome was defined as modified Rankin Scale 0-2 at 3months.RESULTS: Eight hundred thirty-six patients with a final mTICI⩾2b were included in this analysis. FPE was observed in 302 patients (36.1%). In multivariable analysis, hypertension (aOR 1.55, 95% CI 1.10-2.20) and lower baseline NIHSS score (aOR 0.95, 95% CI 0.93-0.97) were independently associated with an FPE. Good outcomes were more common in the FPE versus non-FPE group (72.8% vs 52.8%), and FPE was independently associated with favorable outcome (aOR 2.20, 95% CI 1.59-3.05). 90-day mortality and intracranial hemorrhage (ICH) were significantly lower in the FPE group, 0.43 (95% CI, 0.25-0.72) and 0.55 (95% CI, 0.39-0.77), respectively.CONCLUSION: Over 2/3 of patients with MeVOs and FPE in our cohort had a favorable outcome at 90days. FPE is independently associated with favorable outcomes, it may reduce the risk of any intracranial hemorrhage, and 3-month mortality.
View details for DOI 10.1177/23969873231208276
View details for PubMedID 37885243
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Decreasing false-positive detection of intracranial hemorrhage (ICH) using RAPID ICH 3.
Journal of stroke and cerebrovascular diseases : the official journal of National Stroke Association
2023; 32 (12): 107396
Abstract
INTRODUCTION: The prompt detection of intracranial hemorrhage (ICH) on a non-contrast head CT (NCCT) is critical for the appropriate triage of patients, particularly in high volume/high acuity settings. Several automated ICH detection tools have been introduced; however, at present, most suffer from suboptimal specificity leading to false-positive notifications.METHODS: NCCT scans from 4 large databases were evaluated for the presence of an ICH (IPH, IVH, SAH or SDH) of >0.4 ml using fully-automated RAPID ICH 3.0 as compared to consensus detection from at least two neuroradiology experts. Scans were excluded for (1) severe CT artifacts, (2) prior neurosurgical procedures, or (3) recent intravenous contrast. ICH detection accuracy, sensitivity, specificity, positive predictive value, negative predictive value, and positive and negative likelihood ratios by were determined.RESULTS: A total of 881 studies were included. The automated software correctly identified 453/463 ICH-positive cases and 416/418 ICH-negative cases, resulting in a sensitivity of 97.84% and specificity 99.52%, positive predictive value 99.56%, and negative predictive value 97.65% for ICH detection. The positive and negative likelihood ratios for ICH detection were similarly favorable at 204.49 and 0.02 respectively. Mean processing time was <40 seconds.CONCLUSIONS: In this large data set of nearly 900 patients, the automated software demonstrated high sensitivity and specificity for ICH detection, with rare false-positives.
View details for DOI 10.1016/j.jstrokecerebrovasdis.2023.107396
View details for PubMedID 37883825
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Factors Associated With Fast Early Infarct Growth in Patients With Acute Ischemic Stroke With A Large Vessel Occlusion.
Neurology
2023
Abstract
The optimal methods for predicting early infarct growth rate (EIGR) in acute ischemic stroke with a large vessel occlusion (LVO) have not been established. We aimed to study the factors associated with EIGR, with a focus on the collateral circulation as assessed by the Hypoperfusion Intensity Ratio (HIR) on perfusion imaging, and determine whether the associations found are consistent across imaging modalities.Retrospective multicenter international study including anterior circulation LVO-related acute stroke patients with witnessed stroke onset and baseline perfusion imaging (MRI or CT) performed within 24hrs from symptom onset. To avoid selection bias, patients were selected from (1) the prospective registries of four comprehensive stroke centers with systematic use of perfusion imaging and including both thrombectomy-treated and untreated patients, and (2) one prospective thrombectomy study where perfusion imaging was acquired per protocol but treatment decisions were made blinded to the results. EIGR was defined as infarct volume on baseline imaging divided by onset-to-imaging time, and fast progressors as EIGR ≥10mL/hr. The HIR, defined as the proportion of Tmax>6s with Tmax>10s volume, was measured on perfusion imaging using RAPID software. The factors independently associated with fast progression were studied using multivariable logistic regression models, with separate analyses for CT- and MRI-assessed patients.Overall, 1127 patients were included (CT, n=471; MRI, n=656). Median age was 74 years (IQR, 62-83), 52% were male, median NIHSS was 16 (IQR, 9-21), median HIR was 0.42 (IQR, 0.26-0.58) and 415 (37%) were fast progressors. The HIR was the primary factor associated with fast progression, with very similar results across imaging modalities: the proportion of fast progressors was 4% in the first HIR quartile (i.e. excellent collaterals), ∼15% in the second, ∼50% in the third, and ∼77% in the fourth (P<0.001 for each imaging modality). Fast progression was independently associated with poor 3-month functional outcome in both the CT and MRI cohorts (P<0.001 and P=0.030, respectively).The HIR is the primary factor associated with fast infarct progression, regardless of imaging modality. These results have implication for neuroprotection trial design, as well as informing triage decisions at primary stroke centers.
View details for DOI 10.1212/WNL.0000000000207908
View details for PubMedID 37813579
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Matched-pair analysis of patients with ischemic stroke undergoing thrombectomy using next-generation balloon guide catheters.
Journal of neurointerventional surgery
2023
Abstract
Balloon guide catheters (BGCs) have not been widely adopted, possibly due to the incompatibility of past-generation BGCs with large-bore intermediate catheters. The next-generation BGC is compatible with large-bore catheters. We compared outcomes of thrombectomy cases using BGCs versus conventional guide catheters.We conducted a retrospective study of 110 thrombectomy cases using BGCs (n=55) and non-BGCs (n=55). Sixty consecutive thrombectomy cases in whom the BOBBY BGC was used at a single institution between February 2021 and March 2022 were identified. Of these, 55 BGC cases were 1:1 matched with non-BGC cases by proceduralists, age, gender, stent retriever + aspiration device versus aspiration-only, and site of occlusion. First-pass effect was defined as Thrombolysis In Cerebral Infarction 2b or higher with a single pass.The BGC and non-BGC cohorts had similar mean age (67.2 vs 68.9 years), gender distribution (43.6% vs 47.3% women), median initial National Institutes of Health Stroke Scale score (14 vs 15), and median pretreatment ischemic core volumes (12 mL vs 11.5 mL). BGC and non-BGC cases had similar rates of single pass (60.0% vs 54.6%), first-pass effect (58.2% vs 49.1%), and complications (1.8% vs 9.1%). In aspiration-only cases, the BGC cohort had a significantly higher rate of first-pass effect (100% vs 50.0%, p=0.01). BGC was associated with a higher likelihood of achieving a modified Rankin Scale score of 2 at discharge (OR 7.76, p=0.02). No additional procedural time was required for BGC cases (46.7 vs 48.2 min).BGCs may be safely adopted with comparable procedural efficacy, benefits to aspiration-only techniques, and earlier functional improvement compared with conventional guide catheters.
View details for DOI 10.1136/jnis-2023-020635
View details for PubMedID 37793796
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Larger ischemic cores and poor collaterals among large vessel occlusions presenting in the late evening.
Journal of stroke and cerebrovascular diseases : the official journal of National Stroke Association
2023; 32 (12): 107352
Abstract
BACKGROUND: Components critical to cerebral perfusion have been noted to oscillate over a 24-h cycle. We previously reported that ischemic core volume has a diurnal relationship with stroke onset time when examined as dichotomized epochs (i.e. Day, Evening, Night) in a cohort of over 1,500 large vessel occlusion (LVO) patients. In this follow-up analysis, our goal was to explore if there is a sinusoidal relationship between ischemic core, collateral status (as measured by HIR), and stroke onset time.METHODS: We retrospectively examined collection of LVO patients with baseline perfusion imaging performed within 24 h of stroke onset from four international comprehensive stroke centers. Both ischemic core volume and HIR, were utilized as the primary radiographic parameters. To evaluate for differences in these parameters over a continuous 24-h cycle, we conducted a sinusoidal regression analysis after linearly regressing out the confounders age and time to imaging.RESULTS: A total of 1506 LVO cases were included, with a median ischemic core volume of 13.0 cc (IQR: 0.0-42.0) and median HIR of 0.4 (IQR: 0.2-0.6). Ischemic core volume varied by stroke onset time in the unadjusted (p=0.001) and adjusted (p=0.003) sinusoidal regression analysis with a peak in core volume around 7:45PM. HIR similarly varied by stroke onset time in the unadjusted (p=0.004) and adjusted (p=0.002) models with a peak in HIR values at around 8:18PM.CONCLUSION: The results suggest that critical factors to the development of the ischemic core vary by stroke onset time and peak around 8PM. When placed in the context of prior studies, strongly suggest a diurnal component to the development of the ischemic core.
View details for DOI 10.1016/j.jstrokecerebrovasdis.2023.107352
View details for PubMedID 37801879
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Non-inferiority of deep learning ischemic stroke segmentation on non-contrast CT within 16-hours compared to expert neuroradiologists.
Scientific reports
2023; 13 (1): 16153
Abstract
We determined if a convolutional neural network (CNN) deep learning model can accurately segment acute ischemic changes on non-contrast CT compared to neuroradiologists. Non-contrast CT (NCCT) examinations from 232 acute ischemic stroke patients who were enrolled in the DEFUSE 3 trial were included in this study. Three experienced neuroradiologists independently segmented hypodensity that reflected the ischemic core on each scan. The neuroradiologist with the most experience (expert A) served as the ground truth for deep learning model training. Two additional neuroradiologists' (experts B and C) segmentations were used for data testing. The 232 studies were randomly split into training and test sets. The training set was further randomly divided into 5 folds with training and validation sets. A 3-dimensional CNN architecture was trained and optimized to predict the segmentations of expert A from NCCT. The performance of the model was assessed using a set of volume, overlap, and distance metrics using non-inferiority thresholds of 20%, 3 ml, and 3 mm, respectively. The optimized model trained on expert A was compared to test experts B and C. We used a one-sided Wilcoxon signed-rank test to test for the non-inferiority of the model-expert compared to the inter-expert agreement. The final model performance for the ischemic core segmentation task reached a performance of 0.46 ± 0.09 Surface Dice at Tolerance 5mm and 0.47 ± 0.13 Dice when trained on expert A. Compared to the two test neuroradiologists the model-expert agreement was non-inferior to the inter-expert agreement, [Formula: see text]. The before, CNN accurately delineates the hypodense ischemic core on NCCT in acute ischemic stroke patients with an accuracy comparable to neuroradiologists.
View details for DOI 10.1038/s41598-023-42961-x
View details for PubMedID 37752162
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Combined near infrared photoacoustic imaging and ultrasound detects vulnerable atherosclerotic plaque.
Biomaterials
2023; 302: 122314
Abstract
Atherosclerosis is an inflammatory process resulting in the deposition of cholesterol and cellular debris, narrowing of the vessel lumen and clot formation. Characterization of the morphology and vulnerability of the lesion is essential for effective clinical management. Here, near-infrared auto-photoacoustic (NIRAPA) imaging is shown to detect plaque components and, when combined with ultrasound imaging, to differentiate stable and vulnerable plaque. In an ex vivo study of photoacoustic imaging of excised plaque from 25 patients, 88.2% sensitivity and 71.4% specificity were achieved using a clinically-relevant protocol. In order to determine the origin of the NIRAPA signal, immunohistochemistry, spatial transcriptomics and spatial proteomics were co-registered with imaging and applied to adjacent plaque sections. The highest NIRAPA signal was spatially correlated with bilirubin and associated blood-based residue and with the cytoplasmic contents of inflammatory macrophages bearing CD74, HLA-DR, CD14 and CD163 markers. In summary, we establish the potential to apply the NIRAPA-ultrasound imaging combination to detect vulnerable carotid plaque and a methodology for fusing molecular imaging with spatial transcriptomic and proteomic methods.
View details for DOI 10.1016/j.biomaterials.2023.122314
View details for PubMedID 37776766
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CT perfusion to measure venous outflow in acute ischemic stroke in patients with a large vessel occlusion.
Journal of neurointerventional surgery
2023
Abstract
Robust venous outflow (VO) profiles, measured by degree of venous opacification on pre-thrombectomy CT angiography (CTA) studies, are strongly correlated with favorable outcomes in patients with large vessel occlusion acute ischemic stroke treated by thrombectomy. However, VO measurements are laborious and require neuroimaging expertise.To develop a semi-automated method to measure VO using CTA and CT perfusion imaging studies.We developed a graphical interface using The Visualization Toolkit, allowing for voxel selection at the confluence and bilateral internal cerebral veins on CTA along with arterial input functions (AIFs) from both internal carotid arteries. We extracted concentration-time curves from the CT perfusion study at the corresponding locations associated with AIF and venous output function (VOF). Outcome analyses were primarily conducted by the Mann-Whitney U and Jonckheere-Terpstra tests.Segmentation at the pre-selected AIF and VOF locations was performed on a sample of 97 patients. 65 patients had favorable VO (VO+) and 32 patients had unfavorable VO (VO-). VO+ patients were found to have a significantly shorter VOF time to peak (8.26; 95% CI 7.07 to 10.34) than VO- patients (9.44; 95% CI 8.61 to 10.91), P=0.007. No significant difference was found in VOF curve width and the difference in time between AIF and VOF peaks.Time to peak of VOF at the confluence of sinuses was significantly associated with manually scored venous outflow. Further studies should aim to understand better the association between arterial inflow and venous outflow, and capture quantitative metrics of venous outflow at other locations.
View details for DOI 10.1136/jnis-2023-020727
View details for PubMedID 37643804
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USE-Evaluator: Performance metrics for medical image segmentation models supervised by uncertain, small or empty reference annotations in neuroimaging.
Medical image analysis
2023; 90: 102927
Abstract
Performance metrics for medical image segmentation models are used to measure the agreement between the reference annotation and the predicted segmentation. Usually, overlap metrics, such as the Dice, are used as a metric to evaluate the performance of these models in order for results to be comparable. However, there is a mismatch between the distributions of cases and the difficulty level of segmentation tasks in public data sets compared to clinical practice. Common metrics used to assess performance fail to capture the impact of this mismatch, particularly when dealing with datasets in clinical settings that involve challenging segmentation tasks, pathologies with low signal, and reference annotations that are uncertain, small, or empty. Limitations of common metrics may result in ineffective machine learning research in designing and optimizing models. To effectively evaluate the clinical value of such models, it is essential to consider factors such as the uncertainty associated with reference annotations, the ability to accurately measure performance regardless of the size of the reference annotation volume, and the classification of cases where reference annotations are empty. We study how uncertain, small, and empty reference annotations influence the value of metrics on a stroke in-house data set regardless of the model. We examine metrics behavior on the predictions of a standard deep learning framework in order to identify suitable metrics in such a setting. We compare our results to the BRATS 2019 and Spinal Cord public data sets. We show how uncertain, small, or empty reference annotations require a rethinking of the evaluation. The evaluation code was released to encourage further analysis of this topic https://github.com/SophieOstmeier/UncertainSmallEmpty.git.
View details for DOI 10.1016/j.media.2023.102927
View details for PubMedID 37672900
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Diagnosis and endovascular management of vasospasm after aneurysmal subarachnoid hemorrhage - survey of real-life practices.
Journal of neurointerventional surgery
2023
Abstract
Vasospasm and delayed cerebral ischemia (DCI) are the leading causes of morbidity and mortality after intracranial aneurysmal subarachnoid hemorrhage (aSAH). Vasospasm detection, prevention and management, especially endovascular management varies from center to center and lacks standardization. We aimed to evaluate this variability via an international survey of how neurointerventionalists approach vasospasm diagnosis and endovascular management.We designed an anonymous online survey with 100 questions to evaluate practice patterns between December 2021 and September 2022. We contacted endovascular neurosurgeons, neuroradiologists and neurologists via email and via two professional societies - the Society of NeuroInterventional Surgery (SNIS) and the European Society of Minimally Invasive Neurological Therapy (ESMINT). We recorded the physicians' responses to the survey questions.A total of 201 physicians (25% [50/201] USA and 75% non-USA) completed the survey over 10 months, 42% had >7 years of experience, 92% were male, median age was 40 (IQR 35-46). Both high-volume and low-volume centers were represented. Daily transcranial Doppler was the most common screening method (75%) for vasospasm. In cases of symptomatic vasospasm despite optimal medical management, endovascular treatment was directly considered by 58% of physicians. The most common reason to initiate endovascular treatment was clinical deficits associated with proven vasospasm/DCI in 89%. The choice of endovascular treatment and its efficacy was highly variable. Nimodipine was the most common first-line intra-arterial therapy (40%). Mechanical angioplasty was considered the most effective endovascular treatment by 65% of neurointerventionalists.Our study highlights the considerable heterogeneity among the neurointerventional community regarding vasospasm diagnosis and endovascular management. Randomized trials and guidelines are needed to improve standard of care, determine optimal management approaches and track outcomes.
View details for DOI 10.1136/jnis-2023-020544
View details for PubMedID 37500477
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Hypoperfusion intensity ratio as a predictor of outcomes after thrombectomy triage: A call for data homogeneity.
Interventional neuroradiology : journal of peritherapeutic neuroradiology, surgical procedures and related neurosciences
2023: 15910199231188763
Abstract
BACKGROUND: Collateral blood flow markers have been associated with outcomes after thrombectomy in patients presenting with acute ischemic stroke due to large vessel occlusion (AIS-LVO). Hypoperfusion intensity ratio (HIR), a metric reflecting tissue level collaterals, is one such marker with the potential to delineate patients who do and do not do well after thrombectomy. We determined if HIR correlated with successful reperfusion after thrombectomy.METHODS: Using Nested Knowledge, we screened literature for studies comparing patients with favorable versus unfavorable HIR, distinguished by a cutoff of 0.4, who underwent thrombectomy triage. The primary outcome was reperfusion success, as measured by thrombolysis in cerebral infarction ≥2b and secondary outcomes included rate of symptomatic intracranial hemorrhage, mortality at 90 days, and modified Rankin scale scores 0-2 at 90 days. A random effects model was used to compute pooled prevalence rates and their corresponding 95% confidence intervals (CI).RESULTS: Three studies with 973 patients, 496 with favorable HIR, and 477 with unfavorable HIR were included in this meta-analysis. The odds of reperfusion success were not significantly different between patients who had favorable versus unfavorable HIR (OR 0.96, 95% CI: 0.31-3.04) across two of the studies. Analysis of the remaining outcome variables was precluded by significant heterogeneity in data element reporting.CONCLUSIONS: This meta-analysis was considerably limited by heterogeneity. Future meta-analyses on this topic, and other topics in the field of neurointervention would benefit from improved harmonization of study design and data element reporting.
View details for DOI 10.1177/15910199231188763
View details for PubMedID 37461822
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Decoding the data: a comment on the American Heart Association/American Stroke Association (AHA/ASA) 2023 Guideline for the Management of patients with Aneurysmal Subarachnoid Hemorrhage.
Journal of neurointerventional surgery
2023
View details for DOI 10.1136/jnis-2023-020675
View details for PubMedID 37419695
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Endovascular thrombectomy for ischemic stroke with large core volume: An updated, post-TESLA systematic review and meta-analysis of the randomized trials.
Interventional neuroradiology : journal of peritherapeutic neuroradiology, surgical procedures and related neurosciences
2023: 15910199231185738
Abstract
Limited randomized controlled trials (RCTs) have been performed comparing endovascular thrombectomy (EVT) to medical therapy (MEDT) for acute ischemic stroke with extensive baseline ischemic injury (AIS-EBI). We conducted a systematic review and meta-analysis of RCTs reporting EVT for AIS-EBI.Using the Nested Knowledge AutoLit software, we conducted a systematic literature review from inception to 12 February 2023 within Web of Science, Embase, Scopus, and PubMed databases. Results of the TESLA trial were included on 10 June 2023. We included RCTs that compared EVT to MEDT for AIS with large ischemic core volume. The primary outcome of interest was a modified Rankin Score (mRS) 0-2. Secondary outcomes of interest included early neurological improvement (ENI), mRS 0-3, thrombolysis in cerebral infarction (TICI) 2b-3, symptomatic intracranial hemorrhage (sICH), and mortality. A random-effects model was used to calculate risk ratios (RRs) and their corresponding 95% confidence intervals (CIs).We included four RCTs with 1310 patients, 661 of whom underwent EVT and 649 of whom were treated with MEDT. EVT was associated with greater rates of mRS 0-2 (RR = 2.33, 95% CI = 1.75-3.09; P-value < 0.001), mRS 0-3 (RR = 1.68, 95% CI = 1.33-2.12; P-value < 0.001), and ENI (RR = 2.24, 95% CI = 1.55-3.24; P-value < 0.001). Rates of sICH (RR = 1.99, 95% CI = 1.07-3.69; P-value = 0.03) were greater in the EVT group. Mortality (RR = 0.98, 95% CI = 0.83-1.15; P-value = 0.79) was comparable between the EVT and MEDT groups. The rate of successful reperfusion in the EVT group was 79.9% (95% CI = 75.6-83.6).Although the rate of sICH was greater in the EVT group, EVT conferred a greater clinical benefit to MEDT for AIS-EBI based on available RCTs.
View details for DOI 10.1177/15910199231185738
View details for PubMedID 37376869
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Infarct Core Growth During Interhospital Transfer For Thrombectomy Is Faster At Night.
Stroke
2023
Abstract
Preclinical stroke models have recently reported faster infarct growth (IG) when ischemia was induced during daytime. Considering the inverse rest-activity cycles of rodents and humans, faster IG during the nighttime has been hypothesized in humans.We retrospectively evaluated acute ischemic stroke patients with a large vessel occlusion transferred from a primary to 1 of 3 French comprehensive stroke center, with magnetic resonance imaging obtained at both centers before thrombectomy. Interhospital IG rate was calculated as the difference in infarct volumes on the 2 diffusion-weighted imaging, divided by the time elapsed between the 2 magnetic resonance imaging. IG rate was compared between patients transferred during daytime (7:00-22:59) and nighttime (23:00-06:59) in multivariable analysis adjusting for occlusion site, National Institutes of Health Stroke Scale score, infarct topography, and collateral status.Out of the 329 patients screened, 225 patients were included. Interhospital transfer occurred during nighttime in 31 (14%) patients and daytime in 194 (86%). Median interhospital IG was faster when occurring at night (4.3 mL/h; interquartile range, 1.2-9.5) as compared to the day (1.4 mL/h; interquartile range, 0.4-3.5; P<0.001). In multivariable analysis, nighttime transfer remained independently associated with IG rate (P<0.05).Interhospital IG appeared faster in patients transferred at night. This has potential implications for the design of neuroprotection trials and acute stroke workflow.
View details for DOI 10.1161/STROKEAHA.123.043643
View details for PubMedID 37376988
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Pretreatment brain CT perfusion thresholds for predicting final infarct volume in distal medium vessel occlusions.
Journal of neuroimaging : official journal of the American Society of Neuroimaging
2023
Abstract
BACKGROUND AND PURPOSE: Quantitative CT perfusion (CTP) thresholds for assessing the extent of ischemia in patients with acute ischemic stroke (AIS) have been established; relative cerebral blood flow (rCBF) <30% is typically used for estimating estimated ischemic core volume and Tmax (time to maximum) >6seconds for critical hypoperfused volume in AIS patients with large vessel occlusion (LVO). In this study, we aimed to identify the optimal threshold values for patients presenting with AIS secondary to distal medium vessel occlusions (DMVOs).METHODS: In this retrospective study, consecutive AIS patients with anterior circulation DMVO who underwent pretreatment CTP and follow-up MRI/CT were included. The CTP data were processed by RAPID (iSchemaView, Menlo Park, CA) to generate estimated ischemic core volumes using rCBF <20%, <30%, <34%, and <38% and critical hypoperfused volumes using Tmax (seconds) >4, >6, >8, and >10. Final infarct volumes (FIVs) were obtained from follow-up MRI/CT within 5days of symptom onset. Diagnostic performance between CTP thresholds and FIV was assessed in the successfully and unsuccessfully recanalized groups.RESULTS: Fifty-five patients met our inclusion criteria (32 female [58.2%], 68.0±12.1years old [mean±SD]). Recanalization was attempted with intravenous tissue-type plasminogen activator and mechanical thrombectomy in 27.7% and 38.1% of patients, respectively. Twenty-five patients (45.4%) were successfully recanalized. In the successfully recanalized patients, no CTP threshold significantly outperformed what is used in LVO setting (rCBF<30%). All rCBF CTP thresholds demonstrated fair diagnostic performances for predicting FIV. In unsuccessfully recanalized patients, all Tmax CTP thresholds strongly predicted FIV with relative superiority of Tmax >10seconds (area under the receiver operating characteristic curve=.875, p=.001).CONCLUSION: In AIS patients with DMVOs, longer Tmax delays than Tmax >6seconds, most notably, Tmax >10seconds, best predict FIV in unsuccessfully recanalized patients. No CTP threshold reliably predicts FIV in the successfully recanalized group nor significantly outperformed rCBF<30%.
View details for DOI 10.1111/jon.13142
View details for PubMedID 37357133
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Role of Brain Imaging in the Prediction of Intracerebral Hemorrhage Following Endovascular Therapy for Acute Stroke.
Stroke
2023
Abstract
Currently most acute ischemic stroke patients presenting with a large vessel occlusion are treated with endovascular therapy (EVT), which results in high rates of successful recanalization. Despite this success, more than half of EVT-treated patients are significantly disabled 3 months later partly due to the occurrence of post-EVT intracerebral hemorrhage. Predicting post-EVT intracerebral hemorrhage is important for individualizing treatment strategies in clinical practice (eg, safe initiation of early antithrombotic therapies), as well as in selecting the optimal candidates for clinical trials that aim to reduce this deleterious outcome. Emerging data suggest that brain and vascular imaging biomarkers may be particularly relevant since they provide insights into the ongoing acute stroke pathophysiology. In this review/perspective, we summarize the accumulating literature on the role of cerebrovascular imaging biomarkers in predicting post-EVT-associated intracerebral hemorrhage. We focus on imaging acquired before EVT, during the EVT procedure, and in the early post-EVT time frames when new therapeutic therapies could be tested. Accounting for the complex pathophysiology of post-EVT-associated intracerebral hemorrhage, this review may provide some guidance for future prospective observational or therapeutic studies.
View details for DOI 10.1161/STROKEAHA.123.040806
View details for PubMedID 37334709
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The negative effect of aging on cerebral venous outflow in acute ischemic stroke.
Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism
2023: 271678X231179558
Abstract
Cortical venous outflow (VO) represents an imaging biomarker of increasing interest in patients with acute ischemic stroke due to large vessel occlusion (AIS-LVO). We conducted a retrospective multicenter cohort study to investigate the effect of aging on VO. A total of 784 patients met the inclusion criteria. Cortical Vein Opacification Score (COVES) was used to assess VO profiles on admission CT angiography. Cerebral microperfusion was determined using the hypoperfusion intensity ratio (HIR) derived from perfusion imaging. Arterial collaterals were assessed using the Tan scale. Multivariable regression analysis was performed to identify independent determinants of VO, HIR and arterial collaterals. In multivariable regression, higher age correlated with worse VO (adjusted odds ratio [95% CI]; 0.83 [0.73-0.95]; P = 0.006) and poorer HIR (β coefficient [95% CI], 0.014 [0.005-0.024]; P = 0.002). The negative effect of higher age on VO was mediated by the extent of HIR (17.3%). We conclude that higher age was associated with worse VO in AIS-LVO, partially explained by the extent of HIR reflecting cerebral microperfusion. Our study underlines the need to assess collateral blood flow beyond the arterial system and provides valuable insights into deteriorated cerebral blood supply in elderly AIS-LVO patients.
View details for DOI 10.1177/0271678X231179558
View details for PubMedID 37254736
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Unfavorable Cerebral Venous Outflow is associated with Futile Recanalization in Acute Ischemic Stroke Patients.
European journal of neurology
2023
Abstract
BACKGROUND: Mechanical thrombectomy (MT) has proven to be the standard of care for patients with acute ischemic stroke due to large vessel occlusion (AIS-LVO). However, high revascularization rates do not necessarily result in favorable functional outcomes. We aimed to investigate imaging biomarkers associated with futile recanalization, defined as unfavorable functional outcome despite successful recanalization in AIS-LVO patients.METHODS: Retrospective multicenter cohort study of AIS-LVO patients treated by MT. Successful recanalization was defined as modified Thrombolysis in Cerebral Infarction (mTICI) score of 2b-3. A modified Rankin Scale (mRS) score of 3-6 at 90-days was defined as unfavorable functional outcome. Cortical Vein Opacification Score (COVES) was used to assess venous outflow (VO) and the Tan scale was utilized to determine pial arterial collaterals on admission computed tomography angiography (CTA). Unfavorable VO was defined as COVES ≤2. Multivariable regression analysis was performed to investigate vascular imaging factors associated with futile recanalization.RESULTS: Among 539 patients in which successful recanalization was achieved, unfavorable functional outcome was observed in 59% of patients. 58% of patients had unfavorable VO and 31% exhibited poor pial arterial collaterals. In multivariable regression, unfavorable VO was a strong predictor (adjusted odds ratio [95% CI]; 4.79 [2.48-9.23]) of unfavorable functional outcome despite successful recanalization.CONCLUSION: We observe that unfavorable VO on admission CTA is a strong predictor of unfavorable functional outcomes despite successful vessel recanalization in AIS-LVO patients. Assessment of VO profiles could help as a pretreatment imaging biomarker to determine patients at risk for futile recanalization.
View details for DOI 10.1111/ene.15898
View details for PubMedID 37243906
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Automated cerebral hemorrhage volume calculation and stability detection using automated software.
Research square
2023
Abstract
The measurement of intracerebral hemorrhage (ICH) volume is important for management, particularly in evaluating expansion on subsequent imaging. However manual volumetric analysis is time-consuming, especially in busy hospital settings. We aimed to use automated Rapid Hyperdensity software to accurately measure ICH volume across repeated imaging.We identified ICH cases, with repeat imaging conducted within 24 hours, from two randomized clinical trials where enrollment was not based on ICH volume. Scans were excluded if there was (1) severe CT artifacts, (2) prior neurosurgical procedures, (3) recent intravenous contrast, or (4) ICH < 1 ml. Manual ICH measurements were conducted by one neuroimaging expert using MIPAV software and compared to the performance of automated software.127 patients were included with median baseline ICH volume manually measured at 18.18 cc (IQR: 7.31 - 35.71) compared to automated detection of 18.93 cc (IQR: 7.55, 37.88). The two modalities were highly correlated (r = 0.994, p < 0.001). On repeat imaging, the median absolute difference in ICH volume was 0.68cc (IQR: -0.60-4.87) compared to automated detection at 0.68cc (IQR: -0.45-4.63). These absolute differences were also highly correlated (r = 0.941, p < 0.001), with the ability of the automated software to detect ICH expansion with a Sensitivity of 94.12% and Specificity 97.27%.In our proof-of-concept study, the automated software has high reliability in its ability to quickly determine IPH volume with high sensitivity and specificity and to detect expansion on subsequent imaging.
View details for DOI 10.21203/rs.3.rs-2944493/v1
View details for PubMedID 37292654
View details for PubMedCentralID PMC10246251
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Vascular anomaly, lipoma, and polymicrogyria associated with schizencephaly: developmental and diagnostic insights. Illustrative case.
Journal of neurosurgery. Case lessons
2023; 5 (21)
Abstract
BACKGROUND: Schizencephaly is an uncommon central nervous system malformation. Intracranial lipomas are also rare, accounting for approximately 0.1% of brain "tumors." They are believed to be derived from a persistent meninx primitiva, a neural crest-derived mesenchyme that develops into the dura and leptomeninges.OBSERVATIONS: The authors present a case of heterotopic adipose tissue and a nonshunting arterial vascular malformation arising within a schizencephalic cleft in a 22-year-old male. Imaging showed right frontal gray matter abnormality and an associated suspected arteriovenous malformation with evidence of hemorrhage. Brain magnetic resonance imaging revealed right frontal polymicrogyria lining an open-lip schizencephaly, periventricular heterotopic gray matter, fat within the schizencephalic cleft, and gradient echo hypointensity concerning for prior hemorrhage. Histological assessment demonstrated mature adipose tissue with large-bore, thick-walled, irregular arteries. Mural calcifications and subendothelial cushions suggesting nonlaminar blood flow were observed. There were no arterialized veins or direct transitions from the arteries to veins. Hemosiderin deposition was scant, and hemorrhage was not present. The final diagnosis was consistent with ectopic mature adipose tissue and arteries with meningocerebral cicatrix.LESSONS: This example of a complex maldevelopment of derivatives of the meninx primitiva in association with cortical maldevelopment highlights the unique challenges from both a radiological and histological perspective during diagnostic workup.
View details for DOI 10.3171/CASE2388
View details for PubMedID 37218736
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Comprehensive Venous Outflow Predicts Functional Outcomes in Patients with Acute Ischemic Stroke Treated by Thrombectomy.
AJNR. American journal of neuroradiology
2023
Abstract
Cortical venous outflow has emerged as a robust measure of collateral blood flow in acute ischemic stroke. The addition of deep venous drainage to this assessment may provide valuable information to further guide the treatment of these patients.We performed a multicenter retrospective cohort study of patients with acute ischemic stroke treated by thrombectomy between January 2013 and January 2021. The internal cerebral veins were scored on a scale of 0-2. This metric was combined with existing cortical vein opacification scores to create a comprehensive venous outflow score from 0 to 8 and stratify patients as having favorable-versus-unfavorable comprehensive venous outflow. Outcome analyses were primarily conducted using the Mann-Whitney U and χ2 tests.Six hundred seventy-eight patients met the inclusion criteria. Three hundred fifteen were stratified as having favorable comprehensive venous outflow (mean age, 73 years; range, 62-81 years; 170 men), and 363, as having unfavorable comprehensive venous outflow (mean age, 77 years; range, 67-85 years; 154 men). There were significantly higher rates of functional independence (mRS 0-2; 194/296 versus 37/352, 66% versus 11%, P < .001) and excellent reperfusion (TICI 2c/3; 166/313 versus 142/358, 53% versus 40%, P < .001) in patients with favorable comprehensive venous outflow. There was a significant increase in the association of mRS with the comprehensive venous outflow score compared with the cortical vein opacification score (-0.74 versus -0.67, P = .006).A favorable comprehensive venous profile is strongly associated with functional independence and excellent postthrombectomy reperfusion. Future studies should focus on patients with venous outflow status that is discrepant with the eventual outcome.
View details for DOI 10.3174/ajnr.A7879
View details for PubMedID 37202117
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Elevated Hypoperfusion Intensity Ratio (HIR) observed in patients with a large vessel occlusion (LVO) presenting in the evening.
Journal of stroke and cerebrovascular diseases : the official journal of National Stroke Association
2023; 32 (8): 107172
Abstract
BACKGROUND: Circadian variability has been implicated in timing of stroke onset, yet the full impact of underlying biological rhythms on acute stroke perfusion patterns is not known. We aimed to describe the relationship between time of stroke onset and perfusion profiles in patients with large vessel occlusion (LVO).METHODS: A retrospective observational study was conducted using prospective registries of four stroke centers across North America and Europe with systematic use of perfusion imaging in clinical care. Included patients had stroke due to ICA, M1 or M2 occlusion and baseline perfusion imaging performed within 24h from last-seen-well (LSW). Stroke onset was divided into eight hour intervals: (1) Night: 23:00-6:59, (2) Day: 7:00-14:59, (3) Evening: 15:00-22:59. Core volume was estimated on CT perfusion (rCBF <30%) or DWI-MRI (ADC <620) and the collateral circulation was estimated with the Hypoperfusion Intensity Ratio (HIR=[Tmax>10s]/[Tmax>6s]). Non-parametric testing was conducted using SPSS to account for the non-normalized dependent variables.RESULTS: A total of 1506 cases were included (median age 74.9 years, IQR 63.0-84.0). Median NIHSS, core volumes, and HIR were 14.0 (IQR 8.0-20.0), 13.0mL (IQR 0.0-42.0), and 0.4 (IQR 0.2-0.6) respectively. Most strokes occurred during the Day (n=666, 44.2%), compared to Night (n=360, 23.9%), and Evening (n=480, 31.9%). HIR was highest, indicating worse collaterals, in the Evening compared to the other timepoints (p=0.006). Controlling for age and time to imaging, Evening strokes had significantly higher HIR compared to Day (p=0.013).CONCLUSION: Our retrospective analysis suggests that HIR is significantly higher in the evening, indicating poorer collateral activation which may lead to larger core volumes in these patients.
View details for DOI 10.1016/j.jstrokecerebrovasdis.2023.107172
View details for PubMedID 37196564
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Modern Imaging of Aneurysmal Subarachnoid Hemorrhage.
Radiologic clinics of North America
2023; 61 (3): 457-465
Abstract
In this review, we discuss the imaging of aneurysmal subarachnoid hemorrhage (SAH). We discuss emergency brain imaging, aneurysm detection techniques, and the management of CTA-negative SAH. We also review the concepts of cerebral vasospasm and delayed cerebral ischemia that occurs after aneurysm rupture and their impact on patient outcomes. These pathologies are distinct, and the use of multimodal imaging modalities is essential for prompt diagnosis and management to minimize morbidity from these conditions. Lastly, new advances in artificial intelligence and advanced imaging modalities such as PET and MR imaging scans have been shown to improve the detection of aneurysms and potentially predict outcomes early in the course of SAH.
View details for DOI 10.1016/j.rcl.2023.01.004
View details for PubMedID 36931762
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Imaging Factors Associated With Poor Outcome in Patients With Basilar Artery Occlusion Treated With Endovascular Thrombectomy
STROKE-VASCULAR AND INTERVENTIONAL NEUROLOGY
2023; 3 (3)
View details for DOI 10.1161/SVIN.122.000767
View details for Web of Science ID 001162312700023
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Association Between Intravenous Thrombolysis and Clinical Outcomes Among Patients With Ischemic Stroke and Unsuccessful Mechanical Reperfusion.
JAMA network open
2023; 6 (5): e2310213
Abstract
Clinical evidence of the potential treatment benefit of intravenous thrombolysis preceding unsuccessful mechanical thrombectomy (MT) is scarce.To determine whether intravenous thrombolysis (IVT) prior to unsuccessful MT improves functional outcomes in patients with acute ischemic stroke.Patients were enrolled in this retrospective cohort study from the prospective, observational, multicenter German Stroke Registry-Endovascular Treatment between May 1, 2015, and December 31, 2021. This study compared IVT plus MT vs MT alone in patients with acute ischemic stroke due to anterior circulation large-vessel occlusion in whom mechanical reperfusion was unsuccessful. Unsuccessful mechanical reperfusion was defined as failed (final modified Thrombolysis in Cerebral Infarction grade of 0 or 1) or partial (grade 2a). Patients meeting the inclusion criteria were matched by treatment group using 1:1 propensity score matching.Mechanical thrombectomy with or without IVT.Primary outcome was functional independence at 90 days, defined as a modified Rankin Scale score of 0 to 2. Safety outcomes were the occurrence of symptomatic intracranial hemorrhage and death.After matching, 746 patients were compared by treatment arms (median age, 78 [IQR, 68-84] years; 438 women [58.7%]). The proportion of patients who were functionally independent at 90 days was 68 of 373 (18.2%) in the IVT plus MT and 42 of 373 (11.3%) in the MT alone group (adjusted odds ratio [AOR], 2.63 [95% CI, 1.41-5.11]; P = .003). There was a shift toward better functional outcomes on the modified Rankin Scale favoring IVT plus MT (adjusted common OR, 1.98 [95% CI, 1.35-2.92]; P < .001). The treatment benefit of IVT was greater in patients with partial reperfusion compared with failed reperfusion. There was no difference in symptomatic intracranial hemorrhages between treatment groups (AOR, 0.71 [95% CI, 0.29-1.81]; P = .45), while the death rate was lower after IVT plus MT (AOR, 0.54 [95% CI, 0.34-0.86]; P = .01).These findings suggest that prior IVT was safe and improved functional outcomes at 90 days. Partial reperfusion was associated with a greater treatment benefit of IVT, indicating a positive interaction between IVT and MT. These results support current guidelines that all eligible patients with stroke should receive IVT before MT and add a new perspective to the debate on noninferiority of combined stroke treatment.
View details for DOI 10.1001/jamanetworkopen.2023.10213
View details for PubMedID 37126350
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The Charlotte Large Artery Occlusion Endovascular Therapy Outcome Score Compares Favorably to the Critical Area Perfusion Score for Prognostication Before Basilar Thrombectomy.
Journal of stroke and cerebrovascular diseases : the official journal of National Stroke Association
2023; 32 (7): 107147
Abstract
The Critical Area Perfusion Score (CAPS) predicts functional outcomes in vertebrobasilar thrombectomy patients based on computed tomography perfusion (CTP) hypoperfusion. We compared CAPS to the clinical-radiographic Charlotte Large artery occlusion Endovascular therapy Outcome Score (CLEOS).Acute basilar thrombosis patients from January 2017-December 2021 were included in this retrospective analysis from a health system's stroke registry. Inter-rater reliability was assessed for 6 CAPS raters. A logistic regression with CAPS and CLEOS as predictors was performed to predict 90-day modified Rankin Scale (mRS) score 4-6. Area under the curve (AUC) analyses were performed to evaluate prognostic ability.55 patients, mean age 65.8 (± 13.1) years and median NIHSS score 15.55-24, were included. Light's kappa among 6 raters for favorable versus unfavorable CAPS was 0.633 (95% CI 0.497-0.785). Increased CLEOS was associated with elevated odds of a poor outcome (odds ratio (OR) 1.0010, 95% CI 1.0007-1.0014, p<0.01), though CAPS was not (OR 1.0028, 95% CI 0.9420-1.0676, p=0.93). An overall favorable trend was observed for CLEOS (AUC 0.69, 95% CI 0.54-0.84) versus CAPS (AUC 0.49, 95% CI 0.34-0.64; p=0.051). Among 85.5% of patients with endovascular reperfusion, CLEOS had a statistically higher sensitivity than CAPS at identifying poor 90-day outcomes (71% versus 21%, p=0.003).CLEOS demonstrated better predictive ability than CAPS for poor outcomes overall and in patients achieving reperfusion after basilar thrombectomy.
View details for DOI 10.1016/j.jstrokecerebrovasdis.2023.107147
View details for PubMedID 37119791
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Prediction of delayed cerebral ischemia after cerebral aneurysm rupture using explainable machine learning approach.
Interventional neuroradiology : journal of peritherapeutic neuroradiology, surgical procedures and related neurosciences
2023: 15910199231170411
Abstract
Aneurysmal subarachnoid hemorrhage results in significant mortality and disability, which is worsened by the development of delayed cerebral ischemia. Tests to identify patients with delayed cerebral ischemia prospectively are of high interest.We created a machine learning system based on clinical variables to predict delayed cerebral ischemia in aneurysmal subarachnoid hemorrhage patients. We also determined which variables have the most impact on delayed cerebral ischemia prediction using SHapley Additive exPlanations method.500 aneurysmal subarachnoid hemorrhage patients were identified and 369 met inclusion criteria: 70 patients developed delayed cerebral ischemia (delayed cerebral ischemia+) and 299 did not (delayed cerebral ischemia-). The algorithm was trained based upon age, sex, hypertension (HTN), diabetes, hyperlipidemia, congestive heart failure, coronary artery disease, smoking history, family history of aneurysm, Fisher Grade, Hunt and Hess score, and external ventricular drain placement. Random Forest was selected for this project, and prediction outcome of the algorithm was delayed cerebral ischemia+. SHapley Additive exPlanations was used to visualize each feature's contribution to the model prediction.The Random Forest machine learning algorithm predicted delayed cerebral ischemia: accuracy 80.65% (95% CI: 72.62-88.68), area under the curve 0.780 (95% CI: 0.696-0.864), sensitivity 12.5% (95% CI: -3.7 to 28.7), specificity 94.81% (95% CI: 89.85-99.77), PPV 33.3% (95% CI: -4.39 to 71.05), and NPV 84.1% (95% CI: 76.38-91.82). SHapley Additive exPlanations value demonstrated Age, external ventricular drain placement, Fisher Grade, and Hunt and Hess score, and HTN had the highest predictive values for delayed cerebral ischemia. Lower age, absence of hypertension, higher Hunt and Hess score, higher Fisher Grade, and external ventricular drain placement increased risk of delayed cerebral ischemia.Machine learning models based upon clinical variables predict delayed cerebral ischemia with high specificity and good accuracy.
View details for DOI 10.1177/15910199231170411
View details for PubMedID 37070145
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CT Perfusion vs Noncontrast CT for Late Window Stroke Thrombectomy: A Systematic Review and Meta-analysis.
Neurology
2023
Abstract
Patients with acute ischemic stroke (AIS) treated with endovascular thrombectomy (EVT) in the late window (6-24 hours) can be evaluated with computed tomography perfusion (CTP) or with noncontrast computed tomography (NCCT) only. Whether outcomes differ depending on type of imaging selection is unknown. We conducted a systematic review and meta-analysis comparing outcomes between CTP and NCCT for EVT selection in the late therapeutic window.This study is reported according to the PRISMA 2020 guidelines. A systematic literature review of the English language literature was conducted using Web of Science, Embase, Scopus, and PubMed databases. Papers focusing on late window AIS undergoing EVT imaged via CTP and NCCT were included. Data were pooled using a random-effects model. The primary outcome of interest was rate of functional independence, defined as modified Rankin Scale (mRS) 0-2. Secondary outcomes of interest included rates of successful reperfusion, defined as thrombolysis in cerebral infarction (TICI) 2b-3, mortality, and symptomatic intracranial hemorrhage (sICH).Five studies with 3,384 patients were included in our analysis. There were comparable rates of functional independence (OR= 1.03, 95% CI, 0.87-1.22; P-value= 0.71) and sICH (OR= 1.09, 95% CI, 0.58-2.04; P-value= 0.80) between the two groups. Patients imaged with CTP had higher rates of successful reperfusion (OR= 1.31, 95% CI, 1.05-1.64; P-value= 0.015) and lower rates of mortality (OR= 0.79, 95% CI, 0.65-0.96; P-value= 0.017).Although recovery of functional independence after late window EVT was not more common in patients selected by CTP as compared to patients selected by NCCT only, patients selected by CTP had lower mortality.
View details for DOI 10.1212/WNL.0000000000207262
View details for PubMedID 36990720
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Quantification of Penumbral Volume in Association With Time From Stroke Onset in Acute Ischemic Stroke With Large Vessel Occlusion.
JAMA neurology
2023
Abstract
Importance: The benefit of reperfusion therapies for acute ischemic stroke decreases over time. This decreasing benefit is presumably due to the disappearance of salvageable ischemic brain tissue (ie, the penumbra).Objective: To study the association between stroke onset-to-imaging time and penumbral volume in patients with acute ischemic stroke with a large vessel occlusion.Design, Setting, and Participants: A retrospective, multicenter, cross-sectional study was conducted from January 1, 2015, to June 30, 2022. To limit selection bias, patients were selected from (1) the prospective registries of 2 comprehensive centers with systematic use of magnetic resonance imaging (MRI) with perfusion, including both thrombectomy-treated and untreated patients, and (2) 1 prospective thrombectomy study in which MRI with perfusion was acquired per protocol but treatment decisions were made with clinicians blinded to the results. Consecutive patients with acute stroke with intracranial internal carotid artery or first segment of middle cerebral artery occlusion and adequate quality MRI, including perfusion, performed within 24 hours from known symptoms onset were included in the analysis.Exposures: Time from stroke symptom onset to baseline MRI.Main Outcomes and Measures: Penumbral volume, measured using automated software, was defined as the volume of tissue with critical hypoperfusion (time to maximum >6 seconds) minus the volume of the ischemic core. Substantial penumbra was defined as greater than or equal to 15 mL and a mismatch ratio (time to maximum >6-second volume/core volume) greater than or equal to 1.8.Results: Of 940 patients screened, 516 were excluded (no MRI, n=19; no perfusion imaging, n=59; technically inadequate perfusion imaging, n=75; second segment of the middle cerebral artery occlusion, n=156; unwitnessed stroke onset, n=207). Of 424 included patients, 226 (53.3%) were men, and mean (SD) age was 68.9 (15.1) years. Median onset-to-imaging time was 3.8 (IQR, 2.4-5.5) hours. Only 16 patients were admitted beyond 10 hours from symptom onset. Median core volume was 24 (IQR, 8-76) mL and median penumbral volume was 58 (IQR, 29-91) mL. An increment in onset-to-imaging time by 1 hour resulted in a decrease of 3.1 mL of penumbral volume (beta coefficient=-3.1; 95% CI, -4.6 to -1.5; P<.001) and an increase of 3.0 mL of core volume (beta coefficient=3.0; 95% CI, 1.3-4.7; P<.001) after adjustment for confounders. The presence of a substantial penumbra ranged fromapproximately80% in patients imaged at 1 hour to 70% at 5 hours, 60% at 10 hours, and 40% at 15 hours.Conclusions and Relevance: Time is associated with increasing core and decreasing penumbral volumes. Despite this, a substantial percentage of patients have notable penumbra in extended time windows; the findings of this study suggest that a large proportion of patients with large vessel occlusion may benefit from therapeutic interventions.
View details for DOI 10.1001/jamaneurol.2023.0265
View details for PubMedID 36939736
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Response to Correspondence on "Percutaneous cervical sympathetic block to treat cerebral vasospasm and delayed cerebral ischemia: a review of the evidence" by AL McLean.
Journal of neurointerventional surgery
2023
View details for DOI 10.1136/jnis-2023-020232
View details for PubMedID 36889916
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Into the meta-verse: The decade of global knowledge sharing.
Interventional neuroradiology : journal of peritherapeutic neuroradiology, surgical procedures and related neurosciences
2023: 15910199231154704
View details for DOI 10.1177/15910199231154704
View details for PubMedID 36793231
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The diagnostic performance of artificial intelligence algorithms for identifying M2 segment middle cerebral artery occlusions: A systematic review and meta-analysis.
Journal of neuroradiology = Journal de neuroradiologie
2023
Abstract
Artificial intelligence (AI)-based algorithms have been developed to facilitate rapid and accurate computed tomography angiography (CTA) assessment in proximal large vessel occlusion (LVO) acute ischemic stroke, including internal carotid artery and M1 occlusions. In clinical practice, however, the detection of medium vessel occlusion (MeVO) represents an ongoing diagnostic challenge in which the added value of AI remains unclear.To assess the diagnostic performance of AI platforms for detecting M2 occlusions.Studies that report the diagnostic performance of AI-based detection of M2 occlusions were screened, and sensitivity and specificity data were extracted using the semi-automated AutoLit software (Nested Knowledge, MN) platform. STATA (version 16 IC; Stata Corporation, College Station, Texas, USA) was used to conduct all analyses.Eight studies with a low risk of bias and significant heterogeneity were included in the quantitative and qualitative synthesis. The pooled estimates of sensitivity and specificity of AI platforms for M2 occlusion detection were 64% (95% CI, 53 to 74%) and 97% (95% CI, 84 to 100%), respectively. The area under the curve (AUC) in the SROC curve was 0.79 (95% CI, 0.74 to 0.83).The current performance of the AI-based algorithm makes it more suitable as an adjunctive confirmatory tool rather than as an independent one for M2 occlusions. With the rapid development of such algorithms, it is anticipated that newer generations will likely perform much better.
View details for DOI 10.1016/j.neurad.2023.02.001
View details for PubMedID 36773845
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Determinants of Infarct Core Growth During Inter-hospital Transfer for Thrombectomy.
Annals of neurology
2023
Abstract
OBJECTIVE: Patients with acute ischemic stroke harboring a large vessel occlusion who present to primary stroke centers often require inter-hospital transfer for thrombectomy. We aimed to determine clinical and imaging factors independently associated with fast infarct growth (IG) during inter-hospital transfer.METHODS: We retrospectively analysed data from acute stroke patients with a large vessel occlusion transferred for thrombectomy from a primary stroke center to one of three French comprehensive stroke centers, with an MRI obtained at both the primary and comprehensive center before thrombectomy. Inter-hospital IG rate was defined as the difference in infarct volumes on diffusion-weighted imaging between the primary and comprehensive center, divided by the delay between the two MRI scans. The primary outcome was identification of fast progressors, defined as IG rate ≥5mL/hr. The hypoperfusion intensity ratio (HIR), a surrogate marker of collateral blood flow, was automatically measured on perfusion imaging.RESULTS: A total of 233 patients were included, of whom 27% patients were fast progressors. The percentage of fast progressors was 3% among patients with HIR<0.40 and 71% among those with HIR≥0.40. In multivariable analysis, fast progression was independently associated with HIR, intracranial carotid artery occlusion, and exclusively deep infarct location at the primary center (C-statistic=0.95; 95%CI, 0.93-0.98). IG rate was independently associated with good functional outcome (adjusted OR=0.91; 95%CI 0.83-0.99; P=0.037).INTERPRETATION: Our findings show that a HIR >0.40 is a powerful indicator of fast inter-hospital IG. These results have implication for neuroprotection trial design, as well as informing triage decisions at primary stroke centers. This article is protected by copyright. All rights reserved.
View details for DOI 10.1002/ana.26613
View details for PubMedID 36748945
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Mechanical thrombectomy alone versus with thrombolysis for ischemic stroke: A meta-analysis of randomized trials.
Interventional neuroradiology : journal of peritherapeutic neuroradiology, surgical procedures and related neurosciences
2023: 15910199231154331
Abstract
INTRODUCTION: Mechanical thrombectomy (MT) is the standard of care in eligible patients presenting with acute ischemic stroke (AIS). The question of whether intravenous thrombolysis (IVT) improves outcomes in conjunction with MT remains unanswered. We performed a systematic review and meta-analysis of published randomized controlled trials (RCT) to explore outcomes of MT with and without IVT.METHODS: Following the PRISMA guidelines, a systematic literature review of the English language literature was conducted using PubMed, Embase, Web of science, and Scopus. Outcomes of interest included 90-day modified Rankin Scale (mRS) 0-2, thrombolysis in cerebral infarction (TICI) score 2b-3, symptomatic intracranial hemorrhage (sICH), distal embolization, and mortality. We calculated pooled risk ratios (RRs) and their corresponding 95% confidence intervals (CI).RESULTS: Six RCTs with 2334 patients compared outcomes of patients treated with MT alone and MT with IVT. Both treatments resulted in comparable rates of mRS 0-2 (RR = 0.96, 95% CI = 0.88-1.04; p-value = 0.282), sICH (RR = 0.80, 95% CI = 0.55-1.17; p-value = 0.253), mortality at 90-days (RR = 1.06, 95% CI = 0.88-1.28; p-value = 0.529), and distal embolization (RR = 1.10, 95% CI = 0.79-1.52; p-value = 0.572). MT alone was associated with a lower rate of TICI 2b-3 compared to MT with IVT (RR = 0.96, 95% CI = 0.93-0.99; p-value = 0.006).CONCLUSIONS: In this meta-analysis of six RCTs, MT alone was comparable to MT plus IVT for mRS 0-2, sICH, mortality, and distal embolization; however, MT alone resulted in lower rates of TICI 2b-3. Further trials are needed to determine which patient populations benefit from MT plus IVT and to increase the power of future meta-analyses.
View details for DOI 10.1177/15910199231154331
View details for PubMedID 36734138
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Comparing Tigertriever 13 to other thrombectomy devices for distal medium vessel occlusion: A systematic review and meta-analysis.
Interventional neuroradiology : journal of peritherapeutic neuroradiology, surgical procedures and related neurosciences
2023: 15910199231152510
Abstract
BACKGROUND: There is limited evidence on the optimal endovascular strategy for treatment of distal medium-vessel occlusions (DMVO). The low-profile Tigertriever 13 stent-triever shows early promise as an adaptable device that can navigate the distal vasculature without increasing complication risk in DMVO.METHODS: Using Nested Knowledge, we screened literature for RCTs and cohort studies on the endovascular treatment of DMVO. The primary outcome was reperfusion success, as measured by thrombolysis in cerebral infarction (TICI) ≥ 2b and secondary outcomes included rate of symptomatic intracranial hemorrhage (sICH), mortality at 90 days, and modified Rankin scale (mRS) scores 0-2 at 90 days. A random-effects model was used to compute pooled prevalence rates and their corresponding 95% confidence intervals (CI).RESULTS: Eleven studies with 1402 patients, 167 patients treated by Tigertriever 13 and 1235 patients treated by other devices, were included in the meta-analysis. The rate of reperfusion success was similar in patients treated by Tigertriever 13 (83.2% [95% CI: 71.5-96.7%]) versus other devices (81.6% [95% CI: 75.3-88.4%], p > 0.05). The rate of sICH was also similar in patients treated by Tigertriever 13 (7.2% [95% CI: 4.1-12.5%]) versus other devices (6.9% [95% CI: 5.5-8.8%]). There was significant heterogeneity in the reporting of mortality and mRS.CONCLUSIONS: Tigertriever 13 had similar rates of reperfusion success and sICH as other devices used for the treatment of DMVO. Heterogeneity in data element reporting prevented further analyses. Further studies evaluating Tigertriever 13 and other potential devices in DMVO should attempt to harmonize data element reporting.
View details for DOI 10.1177/15910199231152510
View details for PubMedID 36655307
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Common Data Elements Analysis of Mechanical Thrombectomy Clinical Trials for Acute Ischemic Stroke with Large Core Infarct.
Clinical neuroradiology
2022
Abstract
BACKGROUND: Clinical trials addressing large core acute ischemic stroke (AIS) are ongoing across multiple international groups. Future development of clinical guidelines depends on meta-analyses of these trials calling for adegree of homogeneity of elements across the studies. This common data element study aims to provide an overview of key features of pertinent large core infarct trials.METHODS: PubMed and ClinicalTrials.gov databases were screened for published and ongoing clinical trials assessing mechanical thrombectomy in patients with AIS with large core infarct. Nested Knowledge AutoLit living review platform was utilized to categorize primary and secondary outcomes as well as inclusion and exclusion criteria for patient selection in the trials.RESULTS: The most reported data element was ASPECTS score but with varied definitions of what constitutes large core. Non-utility-weighted modified Rankin score (mRS) was reported in 6/7studies as the primary outcome, while the utility-weighted mRS was the outcome of interest in the TESLA trial, all of them at the 3 months mark, with only LASTE looking for mRS shift at the 6 months mark. Secondary outcomes had more variations. Mortality is reported separately only in 4/7trials, all at the 3‑month mark. Additionally, the TENSION trial reported the frequency of serious adverse events, including mortality, at the 1‑week and 12-month mark.DISCUSSION: Overall, in large core trials there is alarge degree of heterogeneity in the collected data elements. Differences in definition and timepoints render reaching aunified standard difficult, which hinders high quality meta-analyses and cohesive evidence-driven synthesis.
View details for DOI 10.1007/s00062-022-01239-x
View details for PubMedID 36520186
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Correspondence on: 'Artificial intelligence aneurysm measurement tool finds growth in all aneurysms that ruptured during conservative management' by Sahlein et al.
Journal of neurointerventional surgery
2022
View details for DOI 10.1136/jnis-2022-019905
View details for PubMedID 36597940
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Correspondence on: 'Artificial intelligence aneurysm measurement tool finds growth in all aneurysms that ruptured during conservative management' by Sahlein et al
JOURNAL OF NEUROINTERVENTIONAL SURGERY
2022
View details for DOI 10.1136/jnis-2022-019905
View details for Web of Science ID 000899205100001
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Endovascular thrombectomy after acute ischemic stroke of the basilar artery: a meta-analysis of four randomized controlled trials.
Journal of neurointerventional surgery
2022
Abstract
Previous randomized controlled trials (RCTs) and meta-analyses were underpowered to demonstrate the superiority of endovascular thrombectomy (EVT) over medical therapy (MEDT) in the treatment of acute ischemic stroke due to large vessel occlusion of the posterior circulation (PC-LVO). We performed an updated systematic review and meta-analysis after the publication of the BAOCHE and ATTENTION trials to determine whether EVT can benefit patients presenting with PC-LVO.Using Nested Knowledge, we screened literature for RCTs on EVT in PC-LVO. The primary outcome was 90-day modified Rankin Scale (mRS) score 0-3, and secondary outcomes included 90-day mRS score 0-2, 90-day mortality, and rate of symptomatic intracranial hemorrhage (sICH). A random-effects model was used to compute rate ratios (RRs) and their corresponding 95% confidence intervals (CIs).Four RCTs with 988 patients, 556 patients in the EVT arm and 432 patients in the MEDT arm, were included in the meta-analysis. EVT resulted in significantly higher rates of mRS score 0-3 (RR=1.54; 95% CI 1.16 to 2.04; P=0.002) and functional independence (RR=1.83; 95% CI 1.08 to 3.08; P=0.024), and lower rates of mortality (RR=0.76; 95% CI 0.65 to 0.90; P=0.002) at 90-day follow-up compared with MEDT alone. However, EVT patients had higher rates of sICH (RR=7.48; 95% CI 2.27 to 24.61; P<0.001).EVT conferred significant patient benefit over MEDT alone in the treatment of PC-LVO. Future studies should better define patients for whom EVT is futile and determine factors that contribute to higher rates of sICH.
View details for DOI 10.1136/jnis-2022-019776
View details for PubMedID 36597942
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Endovascular thrombectomy after acute ischemic stroke of the basilar artery: a meta-analysis of four randomized controlled trials
JOURNAL OF NEUROINTERVENTIONAL SURGERY
2022
View details for DOI 10.1136/jnis-2022-019776
View details for Web of Science ID 000897877200001
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Percutaneous cervical sympathetic block to treat cerebral vasospasm and delayed cerebral ischemia: a review of the evidence.
Journal of neurointerventional surgery
2022
Abstract
Delayed cerebral ischemia (DCI) affects 30% of patients following aneurysmal subarachnoid hemorrhage (aSAH) and is a major driver of morbidity, mortality, and intensive care unit length of stay for these patients. DCI is strongly associated with cerebral arterial vasospasm, reduced cerebral blood flow and cerebral infarction. The current standard treatment with intravenous or intra-arterial calcium channel antagonist and balloon angioplasty or stent has limited efficacy. A simple treatment such as a cervical sympathetic block (CSB) may be an effective therapy but is not routinely performed to treat vasospasm/DCI. CSB consists of injecting local anesthetic at the level of the cervical sympathetic trunk, which temporarily blocks the innervation of the cerebral arteries to cause arterial vasodilatation. CSB is a local, minimally invasive, low cost and safe technique that can be performed at the bedside and may offer significant advantages as complementary treatment in combination with more conventional neurointerventional surgery interventions. We reviewed the literature that describes CSB for vasospasm/DCI prevention or treatment in humans after aSAH. The studies outlined in this review show promising results for a CSB as a treatment for vasospasm/DCI. Further research is required to standardize the technique, to explore how to integrate a CSB with conventional neurointerventional surgery treatments of vasospasm and DCI, and to study its long-term effect on neurological outcomes.
View details for DOI 10.1136/jnis-2022-019838
View details for PubMedID 36597947
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Percutaneous cervical sympathetic block to treat cerebral vasospasm and delayed cerebral ischemia: a review of the evidence
JOURNAL OF NEUROINTERVENTIONAL SURGERY
2022
View details for DOI 10.1136/jnis-2022-019838
View details for Web of Science ID 000894932400001
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Neuroimaging in Patient Selection for Thrombectomy, From the AJR Special Series on Emergency Radiology.
AJR. American journal of roentgenology
2022
Abstract
Endovascular thrombectomy has become the standard-of-care treatment in carefully selected patients with an acute ischemic stroke due to a large-vessel occlusion of the anterior circulation. Neuroimaging plays a vital role in determining patient eligibility for thrombectomy, both in the early (0-6 hours from symptom onset) and late (>6-24 hours from symptom onset) time windows. Various neuroimaging algorithms are used to determine thrombectomy eligibility, and each algorithm must be optimized for institutional workflow. In this review, we describe common imaging modalities and recommended algorithms for the evaluation of patients for endovascular thrombectomy. We also discuss emerging patient populations that might qualify for thrombectomy in the coming years.
View details for DOI 10.2214/AJR.22.28608
View details for PubMedID 36448911
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Cervical sympathectomy to treat cerebral vasospasm: a scoping review.
Regional anesthesia and pain medicine
2022
Abstract
Delayed cerebral ischemia (DCI) is the second-leading cause of death and disability in patients with aneurysmal subarachnoid hemorrhage (aSAH), and is associated with cerebral arterial vasospasm (CAV). Current treatments for CAV are expensive, invasive, and have limited efficacy. Cervical sympathetic block (CSB) is an underappreciated, but potentially highly effective therapy for CAV.To provide a comprehensive review of the preclinical and human literature pertinent to CSB in the context of CAV.This study followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews guidelines. We conducted a literature search using Embase, PubMed, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, Scopus and Web of Science until February 2022, to identify abstracts, conference proceedings, and full-text papers pertinent to cervical sympathectomy and CAV in animal/adult patients.We included six human and six experimental studies. Human studies were mostly prospective observational, except one retrospective and one randomized clinical trial, and used various imaging modalities to measure changes in arterial diameter after the block. Studies that used digital subtraction angiography showed an improvement in cerebral perfusion without change in vessel diameter. Transcranial Doppler studies found an approximately 15% statistically significant decrease in velocities consistent with arterial vasodilatation. Overall, the results suggest an increase in cerebral arterial diameter and neurological improvement in patients receiving a CSB. Animal studies demonstrate that sympathetic system ablation vasodilates cerebral vasculature and decreases the incidence of symptomatic vasospasm.This scoping review suggests that CSB may be a viable option for treatment and prevention of CAV/DCI in patients with aSAH, although the included studies were heterogeneous, mostly observational, and with a small sample size. Further research is needed to standardize the technique and prove its effectiveness to treat patients suffering of CAV/DCI after aSAH.
View details for DOI 10.1136/rapm-2022-103999
View details for PubMedID 36424089
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Hypoperfusion Intensity Ratio Is Correlated With the Risk of Parenchymal Hematoma After Endovascular Stroke Treatment.
Stroke
2022
Abstract
BACKGROUND: Parenchymal hematoma (PH) is a major complication after endovascular treatment (EVT) for ischemic stroke. The hypoperfusion intensity ratio (HIR) represents a perfusion parameter reflecting arterial collateralization and cerebral microperfusion in ischemic brain tissue. We hypothesized that HIR correlates with the risk of PH after EVT.METHODS: Retrospective multicenter cohort study of patients with large vessel occlusion who underwent EVT between 2013 and 2021 at one of the 2 comprehensive stroke centers (University Medical Center Hamburg-Eppendorf, Germany and Stanford University School of Medicine, CA). HIR was automatically calculated on computed tomography perfusion studies as the ratio of brain volume with time-to-max (Tmax) delay >10 s over volume with Tmax >6 s. Reperfusion hemorrhages were assessed according to the Heidelberg Bleeding Classification. Primary outcome was PH occurrence (PH+) or absence (PH-) on follow-up imaging. Secondary outcome was good clinical outcome defined as a 90-day modified Rankin Scale score of 0 to 2.RESULTS: A total of 624 patients met the inclusion criteria. We observed PH in 91 (14.6%) patients after EVT. PH+ patients had higher HIR on admission compared with PH- patients (median, 0.6 versus 0.4; P<0.001). In multivariable regression, higher admission blood glucose (adjusted odds ratio [aOR], 1.08 [95% CI, 1.04-1.13]; P<0.001), extensive baseline infarct defined as Alberta Stroke Program Early CT Score ≤5 (aOR, 2.48 [1.37-4.42]; P=0.002), and higher HIR (aOR, 1.22 [1.09-1.38]; P<0.001) were independent determinants of PH after EVT. Both higher HIR (aOR, 0.83 [0.75-0.92]; P<0.001) and PH on follow-up imaging (aOR, 0.39 [0.18-0.80]; P=0.013) were independently associated with lower odds of achieving good clinical outcome.CONCLUSIONS: Poorer (higher) HIR on admission perfusion imaging was strongly associated with PH occurrence after EVT. HIR as a surrogate for cerebral microperfusion might reflect tissue vulnerability for reperfusion hemorrhages. This automated and quickly available perfusion parameter might help to assess the need for intensive medical care after EVT.
View details for DOI 10.1161/STROKEAHA.122.040540
View details for PubMedID 36416127
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Association Between Net Water Uptake and Functional Outcome in Patients With Low ASPECTS Brain Lesions: Results From the I-LAST Study.
Neurology
2022
Abstract
BACKGROUND AND OBJECTIVES: The effect of mechanical thrombectomy (MT) on functional outcome in ischemic stroke patients with low ASPECTS is still uncertain. ASPECTS rating is based on the presence of ischemic hypoattenuation relative to normal, however the degree of hypoattenuation, which directly reflects net uptake of water, is currently not considered as imaging biomarker in stroke triage. We hypothesized that the effect of thrombectomy on functional outcome in low ASPECTS patients depends on early lesion water uptake.METHODS: For this multicenter observational study, anterior circulation stroke patients with ASPECTS≤5 were consecutively analyzed. Net water uptake (NWU) was assessed as quantitative imaging biomarker in admission-CT. Primary endpoint was the rate of favorable functional outcome defined as modified Rankin Scale (mRS) score 0-3 at day 90. The effect of recanalization on functional outcome was analyzed according to the degree of NWU within the early infarct lesion.RESULTS: 254 patients were included, of which 148 (58%) underwent MT. The median ASPECTS was 4 (IQR: 3-5), and the median NWU was 11.4% (IQR: 8.9-15.1%). The rate of favorable outcome was 27.6% in patients with low NWU (<11.4%) versus 6.3% in patients with high NWU (≥11.4%; p<0.0001). In multivariable logistic regression analysis, NWU was an independent predictor of outcome, while vessel recanalization (mTICI≥2b) was only significantly associated with better outcomes if NWU was lower than 12.6%. In inverse-probability weighting analysis, recanalization was associated with 20.7% (p=0.01) increase in favorable outcome in patients with low NWU compared to 9.1% (p=0.06) in patients with high NWU.DISCUSSION: Early NWU was independently associated with clinical outcome, and might serve as an indicator of futile MT in low ASPECTS patients. NWU could be tested as tool to select low ASPECTS patients for MT.
View details for DOI 10.1212/WNL.0000000000201601
View details for PubMedID 36414425
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Cerebral perfusion imaging predicts final infarct volume after basilar artery thrombectomy.
Journal of stroke and cerebrovascular diseases : the official journal of National Stroke Association
2022; 32 (1): 106866
Abstract
Cerebral perfusion imaging may be used to identify the ischemic core in acute ischemic stroke (AIS) patients with a large vessel occlusion of the anterior circulation; however, perfusion parameters that predict the ischemic core in AIS patients with a basilar artery occlusion (BAO) are poorly described. We determined which cerebral perfusion parameters best predict the ischemic core after successful endovascular thrombectomy (EVT) in BAO patients.We performed multicenter retrospective study of BAO patients with perfusion imaging before EVT and a DWI after successful EVT. The ischemic core was defined as regions on CTP, which were co-registered to the final DWI infarct. Various time-to-maximum (Tmax) and cerebral blood flow (CBF) thresholds were compared to final infarct volume to determine the best predictor of the final infarct.28 patients were included in the analysis for this study. Tmax >8s (r2: 0.56; median absolute error, 16.0 mL) and Tmax >10s (r2: 0.73; median absolute error, 11.3 mL) showed the strongest agreement between the pre-EVT CTP study and the final DWI. CBF <38% (r2: 0.76; median absolute error, 8.2 mL) and CBF <34% (r2: 0.76; median absolute error, 9.1 mL) also correlated well with final infarct volume on DWI.Pre-EVT CT perfusion imaging is useful to predict the final ischemic infarct volume in BAO patients. Tmax >8s and Tmax >10s were the strongest predictors of the post-EVT final infarct volume.
View details for DOI 10.1016/j.jstrokecerebrovasdis.2022.106866
View details for PubMedID 36427471
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Venous Outflow and Parenchymal Hemorrhage: A Clogged Drain Problem?
STROKE-VASCULAR AND INTERVENTIONAL NEUROLOGY
2022; 2 (6)
View details for DOI 10.1161/SVIN.122.000672
View details for Web of Science ID 001156574700026
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Poor venous outflow profiles increase the risk of reperfusion hemorrhage after endovascular treatment.
Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism
2022: 271678X221127089
Abstract
To investigate whether unfavorable cerebral venous outflow (VO) predicts reperfusion hemorrhage after endovascular treatment (EVT), we conducted a retrospective multicenter cohort study of patients with acute ischemic stroke and large vessel occlusion (AIS-LVO). 629 AIS-LVO patients met inclusion criteria. VO profiles were assessed on admission CT angiography using the Cortical Vein Opacification Score (COVES). Unfavorable VO was defined as COVES ≤2. Reperfusion hemorrhages on follow-up imaging were subdivided into no hemorrhage (noRH), hemorrhagic infarction (HI) and parenchymal hematoma (PH). Patients with PH and HI less frequently achieved good clinical outcomes defined as 90-day modified Rankin Scale scores of ≤2 (PH: 13.6% vs. HI: 24.6% vs. noRH: 44.1%; p<0.001). The occurrence of HI and PH on follow-up imaging was more likely in patients with unfavorable compared to patients with favorable VO (HI: 25.1% vs. 17.4%, p=0.023; PH: 18.3% vs. 8.5%; p=<0.001). In multivariable regression analyses, unfavorable VO increased the likelihood of PH (aOR: 1.84; 95% CI: 1.03-3.37, p=0.044) and HI (aOR: 2.05; 95% CI: 1.25-3.43, p=0.005), independent of age, sex, admission National Institutes Health Stroke Scale scores and arterial collateral status. We conclude that unfavorable VO was associated with the occurrence of HI and PH, both related to worse clinical outcomes.
View details for DOI 10.1177/0271678X221127089
View details for PubMedID 36127828
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Venous Outflow Profiles Are Linked to Clinical Outcomes in Ischemic Stroke Patients with Extensive Baseline Infarct.
Journal of stroke
2022; 24 (3): 372-382
Abstract
BACKGROUND AND PURPOSE: The benefit of endovascular thrombectomy (EVT) treatment is still unclear in stroke patients presenting with extensive baseline infarct. The use of additional imaging biomarkers could improve clinical outcome prediction and individualized EVT selection in this vulnerable cohort. We hypothesized that cerebral venous outflow (VO) may be associated with functional outcomes in patients with low Alberta Stroke Program Early CT Score (ASPECTS).METHODS: We conducted a retrospective multicenter cohort study of patients with acute ischemic stroke due to large vessel occlusion (AIS-LVO). Extensive baseline infarct was defined by an ASPECTS of ≤5 on admission computed tomography (CT). VO profiles were assessed on admission CT angiography using the Cortical Vein Opacification Score (COVES). Favorable VO was defined as COVES ≥3. Multivariable logistic regression was used to determine the association between cerebral VO and good clinical outcomes (90-day modified Rankin Scale score of ≤3).RESULTS: A total of 98 patients met the inclusion criteria. Patients with extensive baseline infarct and favorable VO achieved significantly more often good clinical outcomes compared to patients with unfavorable VO (45.5% vs. 10.5%, P<0.001). Higher COVES were strongly associated with good clinical outcomes (odds ratio, 2.17; 95% confidence interval, 1.15 to 4.57; P=0.024), independent of ASPECTS, National Institutes of Health Stroke Scale, and success of EVT.CONCLUSIONS: Cerebral VO profiles are associated with good clinical outcomes in AIS-LVO patients with extensive baseline infarct. VO profiles could serve as a useful additional imaging biomarker for treatment selection and outcome prediction in low ASPECTS patients.
View details for DOI 10.5853/jos.2022.01046
View details for PubMedID 36221940
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Detection of Early Ischemic Changes with Virtual Noncontrast Dual-Energy CT in Acute Ischemic Stroke: A Noninferiority Analysis.
AJNR. American journal of neuroradiology
2022
Abstract
Dual-energy virtual NCCT has the potential to replace conventional NCCT to detect early ischemic changes in acute ischemic stroke. In this study, we evaluated whether virtual NCCT is noninferior compared with standard linearly blended NCCT, a surrogate of conventional NCCT, regarding the detection of early ischemic changes with ASPECTS.Adult patients who presented with suspected acute ischemic stroke and who underwent dual-energy NCCT and CTA and brain MR imaging within 48 hours were included. Standard linearly blended images were reconstructed to match a conventional NCCT. Virtual NCCT images were reconstructed from CTA. ASPECTS was evaluated on conventional NCCT, virtual NCCT, and DWI, which served as the reference standard. Agreement between CT assessments and the reference standard was evaluated with the Lin concordance correlation coefficient. Noninferiority was assessed with bootstrapped estimates of the differences in ASPECTS between conventional and virtual NCCT with 95% CIs.Of the 193 included patients, 100 patients (52%) had ischemia on DWI. Compared with the reference standard, the ASPECTS concordance correlation coefficient for conventional and virtual NCCT was 0.23 (95% CI, 0.15-0.32) and 0.44 (95% CI, 0.33-0.53), respectively. The difference in the concordance correlation coefficient between virtual and conventional NCCT was 0.20 (95% CI, 0.01-0.39) and did not cross the prespecified noninferiority margin of -0.10.Dual-energy virtual NCCT is noninferior compared with conventional NCCT for the detection of early ischemic changes with ASPECTS.
View details for DOI 10.3174/ajnr.A7600
View details for PubMedID 35953275
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RAPID Aneurysm: Artificial intelligence for unruptured cerebral aneurysm detection on CT angiography.
Journal of stroke and cerebrovascular diseases : the official journal of National Stroke Association
2022; 31 (10): 106690
Abstract
OBJECTIVES: Cerebral aneurysms may result in significant morbidity and mortality. Identification of these aneurysms on CT Angiography (CTA) studies is critical to guide patient treatment. Artificial intelligence platforms to assist with automated aneurysm detection are of high interest. We determined the performance of a semi-automated artificial intelligence software program (RAPID Aneurysm) for the detection of cerebral aneurysms.MATERIALS AND METHODS: RAPID Aneurysm was used to detect retrospectively the presence of cerebral aneurysms in CTA studies performed between January 2019 and December 2020. The gold standard was aneurysm presence and location as determined by the consensus of three expert neuroradiologists. Aneurysm detection accuracy, sensitivity, specificity, positive predictive value, negative predictive value, and positive and negative likelihood ratios by RAPID Aneurysm were determined.RESULTS: 51 patients (mean age, 56±15; 24 women [47.1%]) with a single CTA were included. A total of 60 aneurysms were identified. RAPID Aneurysm had a sensitivity of 0.950 (95% CI: 0.863-0.983), specificity of 1.000 (95% CI: 0.996-1.000), a positive predictive value (PPV) of 1.000 (95% CI: 0.937-1.000), a negative predictive value (NPV) of 0.997 (95% CI: 0.991-0.999), and an accuracy of 0.997 (95% CI: 0.991-0.999) for cerebral aneurysm detection.CONCLUSIONS: RAPID Aneurysm is highly accurate for the detection of cerebral aneurysms on CTA.
View details for DOI 10.1016/j.jstrokecerebrovasdis.2022.106690
View details for PubMedID 35933764
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Anatomy of the Intracranial Arteries: The Anterior Intracranial and Vertebrobasilar Circulations.
Neuroimaging clinics of North America
2022; 32 (3): 617-636
Abstract
The intracranial vasculature, separated into the anterior and posterior circulations, constitute an elegant and complex cerebrovascular bed providing redundant supply to the brain. Here the authors present an anatomic framework for understanding the segmental and branch anatomy, clinically important anastomotic pathways, and pathology of the intracranial arterial system with a focus on angiographic definition.
View details for DOI 10.1016/j.nic.2022.04.007
View details for PubMedID 35843666
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Anatomy of the Intracranial Arteries: The Internal Carotid Artery.
Neuroimaging clinics of North America
2022; 32 (3): 603-615
Abstract
The internal carotid artery is an elegant vessel that is segmentally defined by adjacent anatomic landmarks and defined branch vasculature. Here we describe the segmental and branch angiographic anatomy of the internal carotid artery with particular regard to embryologic development, clinically important anastomotic pathways, and cerebrovascular diseases, such as aneurysm development.
View details for DOI 10.1016/j.nic.2022.04.006
View details for PubMedID 35843665
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Benefit of Intravenous Alteplase Before Thrombectomy Depends on ASPECTS.
Annals of neurology
2022
Abstract
PURPOSE: Baseline variables could be used to guide the administration of additional intravenous alteplase (IVT) before mechanical thrombectomy (MT). The aim of this study was to determine how baseline imaging and demographic parameters modify the effect of IVT on clinical outcomes in patients with ischemic stroke due to large vessel occlusion.METHODS: Multicenter retrospective cohort study of ischemic stroke patients triaged by multimodal-CT undergoing MT treatment after direct admission to an MT-eligible center. Inverse-probability weighting analysis (IPW) was used to assess the treatment effect of IVT adjusted for baseline variables. Multivariable logistic regression analysis with IPW-weighting and interaction terms for IVT was performed to predict functional independence (mRS 0-2 at 90-days).RESULTS: 720 patients were included, of which 366 (51%) received IVT. In IPW, the treatment effect of IVT on outcome (mRS 0-2) distinctively varied according to the ASPECTS subgroup (ASPECTS 9-10: +15%, ASPECTS 6-8: +7%, ASPECTS <6: -11%). In multivariable logistic regression analysis, IVT was independently associated with functional independence (aOR: 1.57, 95%CI: 1.16-2.14, p=0.003) and the interaction term was significant for ASPECTS and IVT revealing that IVT was only significantly associated with better outcomes in patients with higher ASPECTS. No other significant baseline variable interaction terms were identified.INTERPRETATION: ASPECTS was the only baseline variable that showed a significant interaction with IVT for outcome prediction. The application of IVT in patients with an ASPECTS of <6 might have detrimental effects on outcome and may only be considered carefully. This article is protected by copyright. All rights reserved.
View details for DOI 10.1002/ana.26451
View details for PubMedID 35801346
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Intravenous tPA (Tissue-Type Plasminogen Activator) Correlates With Favorable Venous Outflow Profiles in Acute Ischemic Stroke.
Stroke
2022: 101161STROKEAHA122038560
Abstract
BACKGROUND: Intravenous tPA (tissue-type plasminogen activator) is often administered before endovascular thrombectomy (EVT). Recent studies have questioned whether tPA is necessary given the high rates of arterial recanalization achieved by EVT, but whether tPA impacts venous outflow (VO) is unknown. We investigated whether tPA improves VO profiles on baseline computed tomography (CT) angiography (CTA) images before EVT.METHODS: Retrospective multicenter cohort study of patients with acute ischemic stroke due to large vessel occlusion undergoing EVT triage. Included patients underwent CT, CTA, and CT perfusion before EVT. VO profiles were determined by opacification of the vein of Labbe, sphenoparietal sinus, and superficial middle cerebral vein on CTA as 0, not visible; 1, moderate opacification; and 2, full. Pial arterial collaterals were graded on CTA, and tissue-level collaterals were assessed on CT perfusion using the hypoperfusion intensity ratio. Clinical and demographic data were determined from the electronic medical record. Using multivariable regression analysis, we determined the correlation between tPA administration and favorable VO profiles.RESULTS: Seven hundred seventeen patients met inclusion criteria. Three hundred sixty-five patients received tPA (tPA+), while 352 patients were not treated with tPA (tPA-). Fewer tPA+ patients had atrial fibrillation (n=128 [35%] versus n=156 [44%]; P=0.012) and anticoagulants/antiplatelet treatment before acute ischemic stroke due to large vessel occlusion onset (n=130 [36%] versus n=178 [52%]; P<0.001) compared with tPA- patients. One hundred eighty-five patients (51%) in the tPA+ and 100 patients (28%) in the tPA- group exhibited favorable VO (P<0.001). Multivariable regression analysis showed that tPA administration was a strong independent predictor of favorable VO profiles (OR, 2.6 [95% CI, 1.7-4.0]; P<0.001) after control for favorable pial arterial CTA collaterals, favorable tissue-level collaterals on CT perfusion, age, presentation National Institutes of Health Stroke Scale, antiplatelet/anticoagulant treatment, history of atrial fibrillation and time from symptom onset to imaging.CONCLUSIONS: In patients with acute ischemic stroke due to large vessel occlusion undergoing thrombectomy triage, tPA administration was strongly associated with the presence of favorable VO profiles.
View details for DOI 10.1161/STROKEAHA.122.038560
View details for PubMedID 35735008
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Collateral Blood Flow and Ischemic Core Growth.
Translational stroke research
2022
Abstract
Treatment of a large vessel occlusion in the acute ischemic stroke setting focuses on vessel recanalization, and endovascular thrombectomy results in favorable outcomes in appropriate candidates. Expeditious treatment is imperative, but patients often present to institutions that do not have neurointerventional surgeons and need to be transferred to a comprehensive stroke center. These treatment delays are common, and it is important to identify factors that mitigate the progression of the ischemic core in order to maximize the preservation of salvageable brain tissue. Collateral blood flow is the strongest factor known to influence ischemic core growth, which includes the input arterial vessels, tissue-level vessels, and venous outflow. Collateral blood flow at these different levels may be imaged by specific imaging techniques that may also predict ischemic core growth during treatment delays and help identify patients who would benefit from transfer and endovascular therapy, as well as identify those patients in whom transfer may be futile. Here we review collateral blood flow and its relationship to ischemic core growth in stroke patients.
View details for DOI 10.1007/s12975-022-01051-2
View details for PubMedID 35699917
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Aspiration thrombectomy versus stent retriever thrombectomy alone for acute ischemic stroke: evaluating the overlapping meta-analyses.
Journal of neurointerventional surgery
2022
Abstract
BACKGROUND: Previous studies comparing a direct aspiration first pass technique (ADAPT) and stent retrievers have inconsistent methodologies and data reporting, limiting the ability to accurately assimilate data from different studies that would inform treatment of acute ischemic stroke (AIS) treatment.OBJECTIVE: To conduct a systematic review to discuss and compare the findings of all relevant meta-analysis studies comparing the efficacy of the ADAPT and stent retriever techniques.METHODS: The study was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), where meta-analyses comparing the efficacy of the ADAPT technique and stent retrievers in the treatment of AIS were included. We extracted all relevant data from the included studies and assessed the quality of the included meta-analyses using the Assessment of Multiple Systematic Review (AMSTAR-2).RESULTS: Seven relevant studies met our inclusion criteria and were suitable for the qualitative synthesis. All included studies obtained data from randomized controlled trials (RCTs) and observational investigations (including levels II, III, and IV). At the same time, none of them used the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) for quality assessment. In accordance with AMSTAR-2, two studies were rated 'high', while the other five were rated 'moderate'.CONCLUSIONS: Present evidence is insufficient to clarify the superiority of one modality over the other. Further RCTs on this comparison must be conducted prior to designing further meta-analyses or making conclusive interpretations. Procedure duration and cost should be taken into consideration for any future studies.
View details for DOI 10.1136/neurintsurg-2022-018849
View details for PubMedID 35584912
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Favourable arterial, tissue-level and venous collaterals correlate with early neurological improvement after successful thrombectomy treatment of acute ischaemic stroke.
Journal of neurology, neurosurgery, and psychiatry
2022
Abstract
Early neurological improvement (ENI) after thrombectomy is associated with better long-term outcomes in patients with acute ischaemic stroke due to large vessel occlusion (AIS-LVO). Whether cerebral collaterals influence the likelihood of ENI is poorly described. We hypothesised that favourable collateral perfusion at the arterial, tissue-level and venous outflow (VO) levels is associated with ENI after thrombectomy.Multicentre retrospective study of patients with AIS-LVO treated by thrombectomy. Tissue-level collaterals (TLC) were measured on cerebral perfusion studies by the hypoperfusion intensity ratio. VO and pial arterial collaterals (PAC) were determined by the Cortical Vein Opacification Score and the modified Tan scale on CT angiography, respectively. ENI was defined as improvement of ≥8 points or a National Institutes of Health Stroke Scale score of 0 hour or 1 24 hours after treatment. Multivariable regression analyses were used to determine the association of collateral biomarkers with ENI and good functional outcomes (modified Rankin Scale 0-2).646 patients met inclusion criteria. Favourable PAC (OR: 1.9, CI 1.2 to 3.1; p=0.01), favourable VO (OR: 3.3, CI 2.1 to 5.1; p<0.001) and successful reperfusion (OR: 3.1, CI 1.7 to 5.8; p<0.001) were associated with ENI, but favourable TLC were not (p=0.431). Good functional outcomes at 90-days were associated with favourable TLC (OR: 2.2, CI 1.4 to 3.6; p=0.001), VO (OR: 5.7, CI 3.5 to 9.3; p<0.001) and ENI (OR: 5.7, CI 3.3 to 9.8; p<0.001), but not PAC status (p=0.647).Favourable PAC and VO were associated with ENI after thrombectomy. Favourable TLC predicted longer term functional recovery after thrombectomy, but the impact of TLC on ENI is strongly dependent on vessel reperfusion.
View details for DOI 10.1136/jnnp-2021-328041
View details for PubMedID 35577509
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Mechanical thrombectomy in anterior vs. posterior circulation stroke: A systematic review and meta-analysis.
Interventional neuroradiology : journal of peritherapeutic neuroradiology, surgical procedures and related neurosciences
2022: 15910199221100796
Abstract
BACKGROUND: High-quality evidence exists for mechanical thrombectomy (MT) treatment of acute ischemic stroke (AIS) due to large vessel occlusion of the anterior circulation (AC-LVO). The evidence for MT treatment of posterior circulation large vessel occlusion (PC-LVO) is weaker, largely drawn from lower quality studies specific to PC-LVO and extrapolated from findings in AC-LVO, and ambiguous with regards to technical success. We performed a systematic review and meta-analysis to compare the technical success and functional outcomes of MT in PC-LVO versus AC-LVO patients.METHODS: We identified comparative studies reporting on patients treated with MT in AC-LVO versus PC-LVO. The primary outcome of interest was thrombolysis in cerebral infarction (TICI) ≥ 2b. Secondary outcomes included rates of TICI 3, 90-day functional independence, first-pass-effect, average number of passes, and 90-day mortality. A separate random effects model was fit for each outcome measure.RESULTS: Twenty studies with 12,911 patients, 11,299 (87.5%) in the AC-LVO arm and 1612 (12.5%) in the PC-LVO arm, were included. AC-LVO and PC-LVO patients had comparable rates of successful recanalization [OR=1.02 [95% CI: 0.79-1.33], p=0.848). However, the AC-LVO group had greater odds of 90-day functional independence (OR=1.26 [95% CI: 1.00; 1.59], p=0.050) and lower odds of 90-day mortality (OR=0.58 [95% CI: 0.43; 0.79], p=0.002).CONCLUSIONS: MT achieves similar rates of recanalization with a similar safety profile in PC-LVO and AC-LVO patients. Patients with PC-LVO are less likely to achieve functional independence after MT. Future studies should identify PC-LVO patients who are likely to achieve favourable functional outcomes.
View details for DOI 10.1177/15910199221100796
View details for PubMedID 35549748
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Endovascular Therapy Versus Medical Therapy Alone for Basilar Artery Stroke: A Systematic Review and Meta-Analysis Through Nested Knowledge
STROKE-VASCULAR AND INTERVENTIONAL NEUROLOGY
2022; 2 (3)
View details for DOI 10.1161/SVIN.121.000147
View details for Web of Science ID 001157343700001
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Impact of collateral flow on cost-effectiveness of endovascular thrombectomy.
Journal of neurosurgery
2022: 1-10
Abstract
OBJECTIVE: Acute ischemic stroke patients with large-vessel occlusion and good collateral blood flow have significantly better outcomes than patients with poor collateral circulation. The purpose of this study was to evaluate the cost-effectiveness of endovascular thrombectomy (EVT) based on collateral status and, in particular, to analyze its effectiveness in ischemic stroke patients with poor collaterals.METHODS: A decision analysis study was performed with Markov modeling to estimate the lifetime quality-adjusted life-years (QALYs) and associated costs of EVT based on collateral status. The study was performed over a lifetime horizon with a societal perspective in the US setting. Base-case analysis was done for good, intermediate, and poor collateral status. One-way, two-way, and probabilistic sensitivity analyses were performed.RESULTS: EVT resulted in greater effectiveness of treatment compared to no EVT/medical therapy (2.56 QALYs in patients with good collaterals, 1.88 QALYs in those with intermediate collaterals, and 1.79 QALYs in patients with poor collaterals), which was equivalent to 1050, 771, and 734 days, respectively, in a health state characterized by a modified Rankin Scale (mRS) score of 0-2. EVT also resulted in lower costs in patients with good and intermediate collaterals. For patients with poor collateral status, the EVT strategy had higher effectiveness and higher costs, with an incremental cost-effectiveness ratio (ICER) of $44,326/QALY. EVT was more cost-effective as long as it had better outcomes in absolute numbers in at least 4%-8% more patients than medical management.CONCLUSIONS: EVT treatment in the early time window for good outcome after ischemic stroke is cost-effective irrespective of the quality of collateral circulation, and patients should not be excluded from thrombectomy solely on the basis of collateral status. Despite relatively lower benefits of EVT in patients with poor collaterals, even smaller differences in better outcomes have significant long-term financial implications that make EVT cost-effective.
View details for DOI 10.3171/2022.2.JNS212887
View details for PubMedID 35535841
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Automated detection of arterial landmarks and vascular occlusions in patients with acute stroke receiving digital subtraction angiography using deep learning.
Journal of neurointerventional surgery
2022
Abstract
Digital subtraction angiography (DSA) is the gold-standard method of assessing arterial blood flow and blockages prior to endovascular thrombectomy.To detect anatomical features and arterial occlusions with DSA using artificial intelligence techniques.We included 82 patients with acute ischemic stroke who underwent DSA imaging and whose carotid terminus was visible in at least one run. Two neurointerventionalists labeled the carotid location (when visible) and vascular occlusions on 382 total individual DSA runs. For detecting the carotid terminus, positive and negative image patches (either containing or not containing the internal carotid artery terminus) were extracted in a 1:1 ratio. Two convolutional neural network architectures (ResNet-50 pretrained on ImageNet and ResNet-50 trained from scratch) were evaluated. Area under the curve (AUC) of the receiver operating characteristic and pixel distance from the ground truth were calculated. The same training and analysis methods were used for detecting arterial occlusions.The ResNet-50 trained from scratch most accurately detected the carotid terminus (AUC 0.998 (95% CI 0.997 to 0.999), p<0.00001) and arterial occlusions (AUC 0.973 (95% CI 0.971 to 0.975), p<0.0001). Average pixel distances from ground truth for carotid terminus and occlusion localization were 63±45 and 98±84, corresponding to approximately 1.26±0.90 cm and 1.96±1.68 cm for a standard angiographic field-of-view.These results may serve as an unbiased standard for clinical stroke trials, as optimal standardization would be useful for core laboratories in endovascular thrombectomy studies, and also expedite decision-making during DSA-based procedures.
View details for DOI 10.1136/neurintsurg-2021-018638
View details for PubMedID 35483913
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The Cerebral Collateral Cascade: Comprehensive Blood Flow in Ischemic Stroke.
Neurology
2022
Abstract
Robust cerebral collaterals are associated with favorable outcomes in patients with acute ischemic stroke due to large vessel occlusion treated by thrombectomy. However, collateral status assessment mostly relies on single imaging biomarkers and a more comprehensive holistic approach may provide deeper insights into the biology of collateral perfusion on medical imaging. Comprehensive collateralization is defined as blood flow of cerebral arteries through the brain tissue and into draining veins. We hypothesized that a comprehensive analysis of the cerebral collateral cascade (CCC) on an arterial, tissue and venous level would predict clinical and radiological outcomes.Multicenter retrospective cohort study of acute stroke patients undergoing thrombectomy triage. CCC was determined by quantifying pial arterial collaterals, tissue-level collaterals, and venous outflow. Pial arterial collaterals were determined by CT angiography, tissue-level collaterals were assessed on CT perfusion. Venous outflow was assessed on CT angiography using the cortical vein opacification score. 3 groups were defined: CCC+ (good pial collaterals, tissue-level collaterals, and venous outflow), CCC- (poor pial collaterals, tissue-level collaterals, and venous outflow) and CCCmixed (remainder of patients). Primary outcome was functional independence (modified Rankin Scale: 0-2) at 90-days. Secondary outcome was final infarct volume.647 patients met inclusion criteria: 176 CCC+, 345 CCC mixed and 126 CCC-. Multivariable ordinal logistic regression showed that CCC+ predicted good functional outcomes (OR=18.9 [95% CI 8-44.5]; p<0.001) compared to CCC- and CCCmixed patients. CCCmixed patients likely had better functional outcomes compared to CCC- patients (OR=2.5 [95% CI 1.2-5.4]; p=0.014). Quantile regression analysis (50th percentile) showed that CCC+ (β: -78.5, 95% CI -96.0- -61.1; p<0.001) and CCCmixed (β: -64.0, 95% CI -82.4- -45.6; p<0.001) profiles were associated with considerably lower final infarct volumes compared to CCC- profiles.Comprehensive assessment of the collateral blood flow cascade in acute stroke patients is a strong predictor of clinical and radiological outcomes in patients treated by thrombectomy.
View details for DOI 10.1212/WNL.0000000000200340
View details for PubMedID 35483902
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Cerebral Hypoperfusion Intensity Ratio Is Linked to Progressive Early Edema Formation.
Journal of clinical medicine
2022; 11 (9)
Abstract
The hypoperfusion intensity ratio (HIR) is associated with collateral status and reflects the impaired microperfusion of brain tissue in patients with acute ischemic stroke and large vessel occlusion (AIS-LVO). As a deterioration in cerebral blood flow is associated with brain edema, we aimed to investigate whether HIR is correlated with the early edema progression rate (EPR) determined by the ischemic net water uptake (NWU) in a multicenter retrospective analysis of AIS-LVO patients anticipated for thrombectomy treatment. HIR was automatically calculated as the ratio of time-to-maximum (TMax) > 10 s/(TMax) > 6 s. HIRs < 0.4 were regarded as favorable (HIR+) and ≥0.4 as unfavorable (HIR-). Quantitative ischemic lesion NWU was delineated on baseline NCCT images and EPR was calculated as the ratio of NWU/time from symptom onset to imaging. Multivariable regression analysis was used to assess the association of HIR with EPR. This study included 731 patients. HIR+ patients exhibited a reduced median NWU upon admission CT (4% (IQR: 2.1-7.6) versus 8.2% (6-10.4); p < 0.001) and less median EPR (0.016%/h (IQR: 0.007-0.04) versus 0.044%/h (IQR: 0.021-0.089; p < 0.001) compared to HIR- patients. Multivariable regression showed that HIR+ (β: 0.53, SE: 0.02; p = 0.003) and presentation of the National Institutes of Health Stroke Scale (β: 0.2, SE: 0.0006; p = 0.001) were independently associated with EPR. In conclusion, favorable HIR was associated with lower early edema progression and decreased ischemic edema formation on baseline NCCT.
View details for DOI 10.3390/jcm11092373
View details for PubMedID 35566500
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ANA Investigates: Basilar Artery Stroke.
Annals of neurology
2022
View details for DOI 10.1002/ana.26330
View details for PubMedID 35179247
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Common data elements reported on middle meningeal artery embolization in chronic subdural hematoma: an interactive systematic review of recent trials.
Journal of neurointerventional surgery
2022
Abstract
Cross study heterogeneity has limited the evidence based evaluation of middle meningeal artery embolization (MMAE) as a treatment for chronic subdural hematoma (CSDH). Ongoing trials and prospective studies suggest that heterogeneity in upcoming publications may detract from subsequent meta-analyses and systemic reviews. This study aims to describe this data heterogeneity to promote harmonization with common data elements (CDEs) in publications. ClinicalTrials.gov and PubMed were searched for published or ongoing prospective trials of MMAE. The Nested Knowledge AutoLit living review platform was utilized to classify endpoints from randomized control trials (RCTs) and prospective cohort studies comparing MMAE with other treatments. The qualitative synthesis feature was used to determine cross study overlap of outcome related data elements. Eighteen studies were included: 12 RCTs, two non-randomized controlled studies, two prospective single arm trials, one combined prospective and retrospective controlled study, and one prospective cohort study. The most commonly reported data element was recurrence (15/18), but seven heterogenous (non-comparable) definitions were used for 'recurrence'. Mortality was reported in 10/18 studies, but no common timepoint was reported in more than four studies. Re-intervention and CSDH volume were reported in eight studies, CSDH width in seven, and no other outcome was common across more than five studies. There was significant heterogeneity in data element collection even among prospective registered trials of MMAE. Even among CDEs, variation in definition and timepoints prevented harmonization. A standardized approach based on CDEs may be necessary to facilitate future meta-analyses and evidence driven evaluation of MMAE treatment of CSDH.
View details for DOI 10.1136/neurintsurg-2021-018430
View details for PubMedID 35135849
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Artificial Intelligence Prediction Of Delayed Cerebral Ischemia After Cerebral Aneurysm Rupture
LIPPINCOTT WILLIAMS & WILKINS. 2022
View details for DOI 10.1161/str.53.suppl_1.TMP12
View details for Web of Science ID 000788100600184
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Cerebral Perfusion Imaging And Posterior Circulation ASPECTS Identify Stroke Patients Who Benefit From Basilar Artery Thrombectomy
LIPPINCOTT WILLIAMS & WILKINS. 2022
View details for DOI 10.1161/str.53.suppl_1.126
View details for Web of Science ID 000788100600123
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Endovascular Therapy Versus Medical Therapy Alone For Basilar Artery Stroke: A Systematic Review And Meta-analysis Through Nested Knowledge
LIPPINCOTT WILLIAMS & WILKINS. 2022
View details for DOI 10.1161/str.53.suppl_1.TP147
View details for Web of Science ID 000788100600432
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Cost-effectiveness of thrombectomy in patients with minor stroke and large vessel occlusion: effect of thrombus location on cost-effectiveness and outcomes.
Journal of neurointerventional surgery
1800
Abstract
BACKGROUND: To evaluate the cost-effectiveness of endovascular thrombectomy (EVT) to treat large vessel occlusion (LVO) in patients with acute, minor stroke (National Institute of Health Stroke Scale (NIHSS) <6) and impact of occlusion site.METHODS: A Markov decision-analytic model was constructed accounting for both costs and outcomes from a societal perspective. Two different management strategies were evaluated: EVT and medical management. Base case analysis was done for three different sites of occlusion: proximal M1, distal M1 and M2 occlusions. One-way, two-way and probabilistic sensitivity analyses were performed.RESULTS: Base-case calculation showed EVT to be the dominant strategy in 65-year-old patients with proximal M1 occlusion and NIHSS <6, with lower cost (US$37 229 per patient) and higher effectiveness (1.47 quality-adjusted life years (QALYs)), equivalent to 537 days in perfect health or 603 days in modified Rankin score (mRS) 0-2 health state. EVT is the cost-effective strategy in 92.7% of iterations for patients with proximal M1 occlusion using a willingness-to-pay threshold of US$100 000/QALY. EVT was cost-effective if it had better outcomes in 2%-3% more patients than intravenous thrombolysis (IVT) in absolute numbers (base case difference -16%). EVT was cost-effective when the proportion of M2 occlusions was less than 37.1%.CONCLUSIONS: EVT is cost-effective in patients with minor stroke and LVO in the long term (lifetime horizon), considering the poor outcomes and significant disability associated with non-reperfusion. Our study emphasizes the need for caution in interpreting previous observational studies which concluded similar results in EVT versus medical management in patients with minor stroke due to a high proportion of patients with M2 occlusions in the two strategies.
View details for DOI 10.1136/neurintsurg-2021-018375
View details for PubMedID 35022300
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Successful mechanical thrombectomy in acute ischemic stroke: revascularization grade and functional independence.
Journal of neurointerventional surgery
1800
Abstract
Most studies define the technical success of endovascular thrombectomy (EVT) as a Thrombolysis in Cerebral Infarction (TICI) revascularization grade of 2b or higher. However, growing evidence suggests that TICI 3 is the best angiographic predictor of improved functional outcomes. To assess the association between successful TICI revascularization grades and functional independence at 90 days, we performed a systematic review and network meta-analysis of thrombectomy studies that reported TICI scores and functional outcomes, measured by the modified Rankin Scale, using the semi-automated AutoLit software platform. Forty studies with 8691 patients were included in the quantitative synthesis. Across TICI, modified TICI (mTICI), and expanded TICI (eTICI), the highest rate of good functional outcomes was observed in patients with TICI 3 recanalization, followed by those with TICI 2c and TICI 2b recanalization, respectively. Rates of good functional outcomes were similar among patients with either TICI 2c or TICI 3 grades. On further sensitivity analysis of the eTICI scale, the rates of good functional outcomes were equivalent between eTICI 2b50 and eTICI 2b67 (OR 0.81, 95% CI 0.52to 1.25). We conclude that near complete or complete revascularization (TICI 2c/3) is associated with higher rates of functional outcomes after EVT.
View details for DOI 10.1136/neurintsurg-2021-018436
View details for PubMedID 35022301
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Venous outflow profiles are associated with early edema progression in ischemic stroke.
International journal of stroke : official journal of the International Stroke Society
1800: 17474930211065635
Abstract
BACKGROUND: In patients with acute ischemic stroke due to large vessel occlusion (AIS-LVO), development of extensive early ischemic brain edema is associated with poor functional outcomes, despite timely treatment. Robust cortical venous outflow (VO) profiles correlate with favorable tissue perfusion. We hypothesized that favorable VO profiles (VO+) correlate with a reduced early edema progression rate (EPR) and good functional outcomes.METHODS: Multicenter, retrospective analysis to investigate AIS-LVO patients treated by mechanical thrombectomy between May 2013 and December 2020. Baseline computed tomography angiography (CTA) was used to determine VO using the cortical vein opacification score (COVES); VO+ was defined as COVES⩾3 and unfavorable as COVES⩽2. EPR was determined as the ratio of net water uptake (NWU) on baseline non-contrast CT and time from symptom onset to admission imaging. Multivariable regression analysis was performed to assess primary (EPR) and secondary outcome (good functional outcomes defined as 0-2 points on the modified Rankin scale).RESULTS: A total of 728 patients were included. Primary outcome analysis showed VO+ (beta: -0.03, SE: 0.009, p=0.002), lower presentation National Institutes of Health Stroke Scale (NIHSS; beta: 0.002, SE: 0.001, p=0.002), and decreased time from onset to admission imaging (beta: -0.00002, SE: 0.00004, p<0.001) were independently associated with reduced EPR. VO+ also predicted good functional outcomes (odds ratio (OR): 5.07, 95% CI: 2.839-9.039, p<0.001), while controlling for presentation NIHSS, time from onset to imaging, general vessel reperfusion, baseline Alberta Stroke Program Early CT Score, infarct core volume, EPR, and favorable arterial collaterals.CONCLUSIONS: Favorable VO profiles were associated with slower infarct edema progression and good long-term functional outcomes as well as better neurological status and ischemic brain alterations at admission.
View details for DOI 10.1177/17474930211065635
View details for PubMedID 34983276
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Thrombectomy for anterior circulation stroke beyond 6 h from time last known well (AURORA): a systematic review and individual patient data meta-analysis
LANCET
2022; 399 (10321): 249-258
View details for DOI 10.1016/.0140-6736(21)01341-6
View details for Web of Science ID 000746041700020
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Comparison of embolization strategies for mixed plexiform and fistulous brain arteriovenous malformations: a computational model analysis of theoretical risks of nidus rupture.
Journal of neurointerventional surgery
2021
Abstract
BACKGROUND: High-flow fistulas related to plexiform nidi are found in 40% of large brain arteriovenous malformations (AVMs). Endovascular occlusion of intranidal fistulas before plexiform components is empirically considered safe, but potential ensuing dangerous re-routing of flow through plexiform vessels may in theory raise their rupture risk. It remains unclear whether it is safer to embolize plexiform or fistulous vessels initially. We used a novel biomathematical AVM model to compare theoretical hemodynamic changes and rupture risks on sequential embolizations of both types of nidus vessels.METHODS: We computationally modeled a theoretical AVM as an electrical circuit containing a nidus consisting of a massive stochastic network ensemble comprising 1000 vessels. We sampled and individually simulated 10000 different nidus morphologies with a fistula angioarchitecturally isolated from its adjacent plexiform nidus. We used network analysis to calculate mean intravascular pressure (Pmean) and flow rate within each nidus vessel; and Monte Carlo analysis to assess overall risks of nidus rupture when simulating sequential occlusions of vessel types in all 10000 nidi.RESULTS: We consistently observed lower nidus rupture risks with initial fistula occlusion in different network morphologies. Intranidal fistula occlusion simultaneously reduced Pmean and flow rate within draining veins.CONCLUSIONS: Initial occlusion of AVM fistulas theoretically reduces downstream draining vessel hypertension and lowers the risk of rupture of an adjoining plexiform nidus component. This mitigates the theoretical concern that fistula occlusion may cause dangerous redistribution of hemodynamic forces into plexiform nidus vessels, and supports a clinical strategy favoring AVM fistula occlusion before plexiform nidus embolization.
View details for DOI 10.1136/neurintsurg-2021-018067
View details for PubMedID 34893533
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Perfusion Imaging Collateral Scores Predict Infarct Growth in Non-Reperfused DEFUSE 3 Patients.
Journal of stroke and cerebrovascular diseases : the official journal of National Stroke Association
2021; 31 (1): 106208
Abstract
OBJECTIVE: This study evaluated the associations of perfusion imaging collateral profiles with radiographic and clinical outcome in late presenting, non-reperfused patients in the DEFUSE 3 clinical trial.METHODS: Non-reperfused patients in both treatment arms were included. Baseline ischemic core, Tmax >6s, and Tmax >10s perfusion volumes were calculated with RAPID software; infarct volumes obtained 24 hours after randomization were manually determined from DWI or CT. Substantial infarct growth was defined as a >25mL increase between baseline and 24-hour follow-up. Hypoperfusion Intensity Ratio (HIR) was defined as the proportion of the Tmax >6s lesion with Tmax >10s delay; CBV index was calculated by RAPID from mean CBV values within the Tmax >6s lesion compared to regions of normal CBV.RESULTS: Eighty-four patients were included. ROC analysis showed HIR ≥0.34 (AUC=0.68) and CBV index ≤0.74 (AUC=0.72) optimally predicted substantial infarct growth in follow-up. Median growth was 23.4 versus 73.2mL with HIR threshold of 0.34 (p=0.005), and 24.3 versus 58.7mL with CBV index threshold of 0.74 (p=0.004). If baseline HIR and CBV index were both favorable, median growth was 21.7mL, 40.9mL if one was favorable, and 108.2mL if both were unfavorable (p<0.001). Baseline perfusion profile was not associated with 90-day functional outcome.CONCLUSIONS: Perfusion collateral scores forecast infarct growth in late presenting, non-reperfused ischemic stroke patients. These parameters may be useful for guiding transfer decisions, such as need for repeat imaging upon thrombectomy center arrival, and may help identify slow progressing patients more likely to have persistent salvageable ischemic tissue beyond 24 hours.
View details for DOI 10.1016/j.jstrokecerebrovasdis.2021.106208
View details for PubMedID 34823091
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Perfusion Imaging Predicts Favorable Outcomes after Basilar Artery Thrombectomy.
Annals of neurology
2021
Abstract
OBJECTIVE: Perfusion imaging identifies anterior circulation stroke patients who respond favorably to endovascular thrombectomy (ET), but its role in basilar occlusion (BAO) is unknown. We hypothesized that BAO patients with limited regions of severe hypoperfusion (Time-to-maximum [Tmax] delay >10 seconds) would have a favorable response to ET compared to patients with more extensive regions involved.METHODS: We performed a multicenter retrospective cohort study of BAO patients with perfusion imaging prior to ET. We pre-specified a Critical Area Perfusion Score (CAPS; 0-6 points), which quantified severe hypoperfusion (Tmax >10s) in cerebellum (1 point/hemisphere), pons (2 points), midbrain and/or thalamus (2 points). Patients were dichotomized into favorable (CAPS≤3) and unfavorable (CAPS>3) groups. The primary outcome was a favorable functional outcome 90-days after ET (modified Rankin Scale [mRS] 0-3).RESULTS: 103 patients were included. CAPS≤3 patients (87%) had a lower median NIHSS (12.5 [IQR 7-22]) compared to CAPS>3 patients (13%) (23 [IQR 19-36]; p=0.01). Reperfusion was achieved in 84% of all patients with no difference between CAPS groups (p=0.42). 64% of reperfused CAPS≤3 patients had a favorable outcome compared to 8% of non-reperfused CAPS≤3 patients (OR=21.0 [95% CI 2.6-170]; p<0.001). No CAPS>3 patients had a favorable outcome, regardless of reperfusion. In a multivariable regression analysis, CAPS≤3 was a robust independent predictor of favorable outcome after adjustment for reperfusion, age, and pre-ET NIHSS (OR 39.25 [95% CI 1.34->999)]; p=0.04).INTERPRETATION: BAO patients with limited regions of severe hypoperfusion had a favorable response to reperfusion following ET. However, patients with more extensive regions of hypoperfusion in critical brain regions did not benefit from endovascular reperfusion. This article is protected by copyright. All rights reserved.
View details for DOI 10.1002/ana.26272
View details for PubMedID 34786756
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What predicts poor outcome after successful thrombectomy in early time window?
Journal of neurointerventional surgery
2021
Abstract
BACKGROUND: Half of the patients with large vessel occlusion (LVO)-related acute ischemic stroke (AIS) who undergo endovascular reperfusion are dead or dependent at 3 months. We hypothesize that in addition to established prognostic factors, baseline imaging profile predicts outcome among reperfusers.METHODS: Consecutive patients receiving endovascular treatment (EVT) within 6hours after onset with Thrombolysis In Cerebral Infarction (TICI) 2b, 2c and 3 revascularization were included. Poor outcome was defined by a modified Rankin scale (mRS) 3-6 at 90 days. No mismatch (NoMM) profile was defined as a mismatch (MM) ratio ≤1.2 and/or a volume <10mL on pretreatment imaging.RESULTS: 187 patients were included, and 81 (43%) had a poor outcome. Median delay from stroke onset to the end of EVT was 259min (IQR 209-340). After multivariable logistic regression analysis, older age (OR 1.26, 95% CI 1.06 to 1.5; p=0.01), higher National Institutes of Health Stroke Scale (NIHSS) (OR 1.15, 95% CI 1.06 to 1.25; p<0.0001), internal carotid artery (ICA) occlusion (OR 3.02, 95% CI 1.2 to 8.0; p=0.021), and NoMM (OR 4.87, 95% CI 1.09 to 22.8; p=0.004) were associated with poor outcome. In addition, post-EVT hemorrhage (OR 3.64, 95% CI 1.5 to 9.1; p=0.04) was also associated with poor outcome.CONCLUSIONS: The absence of a penumbra defined by a NoMM profile on baseline imaging appears to be an independent predictor of poor outcome after reperfusion. Strategies aiming to preserve the penumbra may be encouraged to improve these patients' outcomes.
View details for DOI 10.1136/neurintsurg-2021-017946
View details for PubMedID 34750109
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Cerebral venous outflow profiles are associated with the first pass effect in endovascular thrombectomy.
Journal of neurointerventional surgery
2021
Abstract
BACKGROUND: Recent studies found that favorable venous outflow (VO) profiles are associated with higher reperfusion rates after mechanical thrombectomy (MT) in patients with acute ischemic stroke due to large vessel occlusion (AIS-LVO). Fewer retrieval attempts and first-pass revascularization during MT lead to better functional outcomes.OBJECTIVE: To examine the hypothesis that favorable VO profiles assessed on baseline CT angiography (CTA) images correlate with successful vessel reperfusion after the first retrieval attempt and fewer retrieval attempts.METHODS: A multicenter retrospective cohort study of patients with AIS-LVO treated by MT. Baseline CTA was used to determine the cortical vein opacification score (COVES). Favorable VO was defined as COVES ≥3. Primary outcomes were successful with excellent vessel reperfusion status, defined as Thrombolysis in Cerebral Infarction (TICI) 2b/3 and 2c/3 after first retrieval attempt.RESULTS: 617 patients were included in this study, of whom 205 (33.2%) had first pass reperfusion. In univariate analysis, ordinal COVES (p=0.011) values were significantly higher in patients with first pass than in those with non-first pass reperfusion, while the number of patients exhibiting favorable pial arterial collaterals using the Maas scale on CTA did not differ (p=0.243). In multivariable logistic regression analysis, higher COVES were independently associated with TICI 2b/3 (OR=1.25, 95%CI 1.1 to 1.42; p=0.001) and TICI 2c/3 (OR=1.2, 95%CI 1.04 to 1.36; p=0.011) reperfusion after one retrieval attempt, controlling for penumbra volume and time from symptom onset to vessel reperfusion.CONCLUSIONS: Favorable VO, classified as higher COVES, is independently associated with successful and excellent first pass reperfusion in patients with AIS-LVO treated by endovascular thrombectomy.
View details for DOI 10.1136/neurintsurg-2021-018078
View details for PubMedID 34750110
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Cerebral Perfusion in Pediatric Stroke: Children Are Not Little Adults.
Topics in magnetic resonance imaging : TMRI
2021; 30 (5): 245-252
Abstract
ABSTRACT: Cerebral perfusion imaging provides useful information about the hemodynamic state of the brain that is relevant to a number of neurologic conditions, including stroke, epilepsy, and brain tumors. Multiple imaging modalities have been developed to evaluate brain perfusion, primarily by the use of different tracers to measure cerebral blood volume and cerebral blood flow. Here, we provide an overview of magnetic resonance imaging perfusion techniques; summarize the role of perfusion imaging in adult stroke; describe changes in cerebral blood flow over childhood; and discuss the relevance and future directions of perfusion imaging in pediatric cerebrovascular disorders and stroke.
View details for DOI 10.1097/RMR.0000000000000275
View details for PubMedID 34613947
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Definitive Diagnostic Evaluation of the Child With Arterial Ischemic Stroke and Approaches to Secondary Stroke Prevention.
Topics in magnetic resonance imaging : TMRI
2021; 30 (5): 225-230
Abstract
ABSTRACT: In children with arterial ischemic stroke (AIS), the definitive diagnosis of stroke subtype and confirmation of stroke etiology is necessary to mitigate stroke morbidity and prevent recurrent stroke. The common causes of AIS in children are sharply differentiated from the common causes of adult AIS. A comprehensive, structured diagnostic approach will identify the etiology of stroke in most children. Adequate diagnostic evaluation relies on advanced brain imaging and vascular imaging studies. A variety of medical and surgical secondary stroke prevention strategies directed at the underlying cause of stroke are available. This review aims to outline strategies for definitive diagnosis and secondary stroke prevention in children with AIS, emphasizing the critical role of neuroimaging.
View details for DOI 10.1097/RMR.0000000000000272
View details for PubMedID 34613945
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Reperfusion Therapies for Children With Arterial Ischemic Stroke.
Topics in magnetic resonance imaging : TMRI
2021; 30 (5): 231-243
Abstract
ABSTRACT: Modern hyperacute reperfusion therapies including intravenous thrombolysis and mechanical thrombectomy have transformed the management of arterial ischemic stroke (AIS) in adults. Multiple randomized clinical trials have demonstrated that these therapies enable remarkable improvements in clinical outcome for properly selected patients with AIS. Because pediatric patients were excluded from predicate clinical trials, there is a conspicuous lack of data to guide selection of therapies and inform age-adjusted and pathology-oriented treatment modifications for children. Specifically, technical guidance concerning treatment eligibility, drug dosing, and device implementation is lacking. This review aims to outline important features that differentiate pediatric AIS from adult AIS and provide practical strategies that will assist the stroke specialist with therapeutic decision making.
View details for DOI 10.1097/RMR.0000000000000273
View details for PubMedID 34613946
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Initial Diagnostic Evaluation of the Child With Suspected Arterial Ischemic Stroke.
Topics in magnetic resonance imaging : TMRI
2021; 30 (5): 211-223
Abstract
ABSTRACT: Numerous factors make the initial diagnostic evaluation of children with suspected arterial ischemic stroke (AIS) a relatively unsettling challenge, even for the experienced stroke specialist. The low frequency of pediatric AIS, diversity of unique age-oriented stroke phenotypes, and unconventional approaches required for diagnosis and treatment all contribute difficulty to the process. This review aims to outline important features that differentiate pediatric AIS from adult AIS and provide practical strategies that will assist the stroke specialist with diagnostic decision making in the initial phase of care.
View details for DOI 10.1097/RMR.0000000000000276
View details for PubMedID 34613944
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Distinct intraarterial Clot Localizations affect Tissue-Level Collaterals and Venous Outflow Profiles.
European journal of neurology
2021
Abstract
BACKGROUND AND AIM: Arterial clot localization affects collateral flow to ischemic brain in patients with acute ischemic stroke due to large vessel occlusion (AIS-LVO). We determined the association between vessel occlusion locations, tissue-level collaterals (TLC) and venous outflow (VO) profiles and their impact on good functional outcomes.MATERIALS AND METHODS: Multicenter retrospective cohort study of consecutive AIS-LVO patients who underwent thrombectomy triage. Baseline CT angiography (CTA) was used to localize vessel occlusion, which was dichotomized into proximal vessel occlusion (PVO; internal carotid artery and proximal M1) and distal vessel occlusion (DVO; distal M1 and M2) and to assess collateral score. TLC were assessed on CT perfusion data using the Hypoperfusion Intensity Ratio (HIR). VO was determined on baseline CTA by the cortical vein opacification score. Primary outcomes were favorable VO and TLC, secondary outcome the Modified Ranking Scale (mRS) after 90 days.RESULTS: 649 patients met inclusion criteria. 376 patients (58%) had a PVO and 273 patients (42%) had a DVO. Multivariable ordinal logistic regression showed that DVO predicted favorable TLC (OR=1.77 [95% CI: 1.24-2.52]; p=0.002) and favorable VO (OR=7.2 [95% CI: 5.2-11.9]; p<0.001). DVO (OR=3.4 [95% CI: 2.1-5.6]; p<0.001), favorable VO (OR=6.4 [95% CI: 3.8-10.6]; p<0.001) and favorable TLC (OR=3.2 [95% CI: 2-5.3]; p<0.001), but not CTA collaterals (OR=1.07 [95% CI: 0.60-1.91]; p=0.813), were predictors of good functional outcome.CONCLUSION: DVO in AIS-LVO patients correlate with favorable TLC and VO profiles, which are associated with good functional outcome.
View details for DOI 10.1111/ene.15079
View details for PubMedID 34424584
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Rethinking the Collateral Vasculature Assessment in Acute Ischemic Stroke: The Comprehensive Collateral Cascade.
Topics in magnetic resonance imaging : TMRI
2021; 30 (4): 181-186
Abstract
ABSTRACT: Occlusion of a cervical or cerebral artery results in disruption of blood flow to the brain and may result in irreversible infarction. Intracranial pial collaterals are a network of arteries that may preserve blood flow to otherwise critically hypoperfused brain areas until vessel recanalization is achieved. The robustness of these arterial collaterals is pivotal for the survivability of ischemic brain tissue and is associated with treatment success and long-term clinical outcome. More recently, the importance of venous outflow from ischemic brain tissue has been appreciated. Arterial collaterals and venous outflow are evaluated by neuroimaging parameters, and recent imaging advances have enabled a more comprehensive assessment of the entire collateral cascade in patients with acute ischemic stroke. Here we review novel imaging biomarkers for the assessment of arterial collaterals, tissue-level collateral blood flow, and venous outflow. We also summarize how a more comprehensive assessment of the cerebral blood flow leads to a better prediction of treatment efficacy and improved clinical outcomes.
View details for DOI 10.1097/RMR.0000000000000274
View details for PubMedID 34397967
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Improving Ischemic Stroke Care With MRI and Deep Learning Artificial Intelligence.
Topics in magnetic resonance imaging : TMRI
2021; 30 (4): 187-195
Abstract
ABSTRACT: Advanced magnetic resonance imaging has been used as selection criteria for both acute ischemic stroke treatment and secondary prevention. The use of artificial intelligence, and in particular, deep learning, to synthesize large amounts of data and to understand better how clinical and imaging data can be leveraged to improve stroke care promises a new era of stroke care. In this article, we review common deep learning model structures for stroke imaging, evaluation metrics for model performance, and studies that investigated deep learning application in acute ischemic stroke care and secondary prevention.
View details for DOI 10.1097/RMR.0000000000000290
View details for PubMedID 34397968
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Assessment of Optimal Patient Selection for Endovascular Thrombectomy Beyond 6 Hours After Symptom Onset: A Pooled Analysis of the AURORA Database.
JAMA neurology
2021
Abstract
Importance: The optimal imaging approach for identifying patients who may benefit from endovascular thrombectomy (EVT) beyond 6 hours after they were last known well is unclear. Six randomized clinical trials (RCTs) have evaluated the efficacy of EVT vs standard medical care among patients with ischemic stroke.Objective: To assess the benefits of EVT among patients with 3 baseline imaging profiles using a pooled analysis of RCTs.Data Sources: The AURORA (Analysis of Pooled Data from Randomized Studies of Thrombectomy More Than 6 Hours After Last Known Well) Collaboration pooled patient-level data from the included clinical trials.Study Selection: An online database search identified RCTs of endovascular stroke therapy published between January 1, 2010, and March 1, 2021, that recruited patients with ischemic stroke who were randomized between 6 and 24 hours after they were last known well.Data Extraction/Synthesis: Data from the final locked database of each study were provided. Data were pooled, and analyses were performed using mixed-effects modeling with fixed effects for parameters of interest.Main Outcomes and Measures: The primary outcome was reduction in disability measured by the modified Rankin Scale at 90 days. An evaluation was also performed to examine whether the therapeutic response differed based on imaging profile among patients who received treatment based on the time they were last known well. Treatment benefits were assessed among a clinical mismatch subgroup, a target perfusion mismatch subgroup, and an undetermined profile subgroup. The primary end point was assessed among these subgroups and during 3 treatment intervals (tercile 1, 360-574 minutes [6.0-9.5 hours]; tercile 2, 575-762 minutes [9.6-12.7 hours]; and tercile 3, 763-1440 minutes [12.8-24.0 hours]).Results: Among 505 eligible patients, 266 (mean [SD] age, 68.4 [13.8] years; 146 women [54.9%]) were assigned to the EVT group and 239 (mean [SD] age, 68.7 [13.7] years; 126 men [52.7%]) were assigned to the control group. Among 295 patients in the clinical mismatch subgroup and 359 patients in the target perfusion mismatch subgroup, EVT was associated with reductions in disability at 90 days vs no EVT (clinical mismatch subgroup, odds ratio [OR], 3.57; 95% CI, 2.29-5.57; P<.001; target perfusion mismatch subgroup, OR, 3.13; 95% CI, 2.10-4.66; P=.001). Statistically significant benefits were observed in all 3 terciles for both subgroups, with the highest OR observed for tercile 3 (clinical mismatch subgroup, OR, 4.95; 95% CI, 2.20-11.16; P < .001; target perfusion mismatch subgroup, OR, 5.01; 95% CI, 2.37-10.60; P < .001). A total of 132 patients (26.1%) had an undetermined imaging profile and no significant treatment benefit (OR, 1.59; 95% CI, 0.82-3.06; P=.17). The interaction between treatment effects for the clinical and target perfusion mismatch subgroups vs the undetermined profile subgroup was significant (OR, 2.28; 95% CI, 1.11-4.70; P=.03).Conclusions and Relevance: In this study, EVT was associated with similar benefit among patients in the clinical mismatch and target perfusion mismatch subgroups during the 6- to 24-hour treatment interval. These findings support EVT as a treatment for patients meeting the criteria for either of the imaging mismatch profiles within the 6- to 24-hour interval.
View details for DOI 10.1001/jamaneurol.2021.2319
View details for PubMedID 34309619
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Realistic generation of diffusion-weighted magnetic resonance brain images with deep generative models.
Magnetic resonance imaging
2021
Abstract
We study two state of the art deep generative networks, the Introspective Variational Autoencoder and the Style-Based Generative Adversarial Network, for the generation of new diffusion-weighted magnetic resonance images. We show that high quality, diverse and realistic-looking images, as evaluated by external neuroradiologists blinded to the whole study, can be synthesized using these deep generative models. We evaluate diverse metrics with respect to quality and diversity of the generated synthetic brain images. These findings show that generative models could qualify as a method for data augmentation in the medical field, where access to large image database is in many aspects restricted.
View details for DOI 10.1016/j.mri.2021.06.001
View details for PubMedID 34116133
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MR perfusion imaging: Half-dose gadolinium is half the quality.
Journal of neuroimaging : official journal of the American Society of Neuroimaging
2021
Abstract
BACKGROUND AND PURPOSE: Patients with acute ischemic stroke due to a large vessel occlusion (AIS-LVO) undergo emergent neuroimaging triage for thrombectomy treatment. MRI is often utilized for this evaluation, and cerebral magnetic resonance perfusion (MRP) imaging is used to identify the presence of the salvageable penumbra. To determine if dose reduction is feasible, we assessed whether a half-dose reduction in gadobenate provided sufficient MRP quality in AIS-LVO patients.METHODS: A prospective observational study of all patients presenting to our neurovascular referral center with AIS-LVO was performed. MRP was done with a half-dose of gadolinium (0.1 ml/kg body weight) over a period of 10 months. MRP images were compared to a consecutive historical cohort of full-dose gadolinium (0.2 ml/kg body weight) MRP studies and rated for image quality (poor, borderline, or good) that determined thrombectomy eligibility.RESULTS: Fifty-four half-dose and 127 full-dose patients were included. No differences in patient demographics or stroke presentation details were identified. MRP quality differed between half- and full-dose scans (p < 0.001), which were rated as poor (40.7% vs. 6.3%), borderline (18.5% vs. 26.8%), and good quality (40.7% vs. 66.9%), respectively. MRP image quality was then dichotomized into poor and sufficient (borderline and good) quality groups; half-dose studies were more likely to have poor quality compared to full-dose studies (40.7% vs. 6.3%; p < 0.001).CONCLUSIONS: Half-dose gadolinium administration for MRP in AIS-LVO patients results in poor image quality in a substantial number of studies. MR cerebral perfusion performed with half-dose gadolinium may adversely affect stroke patient triage for thrombectomy.
View details for DOI 10.1111/jon.12879
View details for PubMedID 34002424
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Assistance from Automated ASPECTS Software Improves Reader Performance.
Journal of stroke and cerebrovascular diseases : the official journal of National Stroke Association
2021; 30 (7): 105829
Abstract
PURPOSE: To compare physicians' ability to read Alberta Stroke Program Early CT Score (ASPECTS) in patients with a large vessel occlusion within 6 hours of symptom onset when assisted by a machine learning-based automatic software tool, compared with their unassisted score.MATERIALS AND METHODS: 50 baseline CT scans selected from two prior studies (CRISP and GAMES-RP) were read by 3 experienced neuroradiologists who were provided access to a follow-up MRI. The average ASPECT score of these reads was used as the reference standard. Two additional neuroradiologists and 6 non-neuroradiologist readers then read the scans both with and without assistance from the software reader-augmentation program and reader improvement was determined. The primary hypothesis was that the agreement between typical readers and the consensus of 3 expert neuroradiologists would be improved with software augmented vs. unassisted reads. Agreement was based on the percentage of the individual ASPECT regions (50 cases, 10 regions each; N=500) where agreement was achieved.RESULTS: Typical non-neuroradiologist readers agreed with the expert consensus read in 72% of the 500 ASPECTS regions, evaluated without software assistance. The automated software alone agreed in 77%. When the typical readers read the scan in conjunction with the software, agreement improved to 78% (P<0.0001, test of proportions). The software program alone achieved correlations for total ASPECT scores that were similar to the expert readers who had access to the follow-up MRI scan to help enhance the quality of their reads.CONCLUSION: Typical readers had statistically significant improvement in their scoring of scans when the scan was read in conjunction with the automated software, achieving agreement rates that were comparable to neuroradiologists.
View details for DOI 10.1016/j.jstrokecerebrovasdis.2021.105829
View details for PubMedID 33989968
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Association of Venous Outflow Profiles and Successful Vessel Reperfusion After Thrombectomy.
Neurology
2021
Abstract
OBJECTIVE: Robust arterial collaterals are associated with successful reperfusion after thrombectomy treatment of acute ischemic stroke due to large vessel occlusion (AIS-LVO). Excellent venous outflow (VO) reflects excellent tissue perfusion and collateral status in AIS-LVO patients. To determine whether favorable VO profiles assessed on pre-treatment CT angiography (CTA) images correlate with successful vessel reperfusion after thrombectomy in AIS-LVO patients.METHODS: Multicenter retrospective cohort study of consecutive AIS-LVO patients treated by thrombectomy. Baseline CTA was used to assess collateral status (Tan scale) and VO using the cortical vein opacification score (COVES). Favorable VO was defined as COVES ≥3. Primary outcome was excellent vessel reperfusion status (modified Thrombolysis In Cerebral Infarction [TICI] 2c-3). Secondary outcome was good functional outcome defined as 0-2 on the Modified Ranking Scale (mRS) after 90 days.RESULTS: 565 patients met inclusion criteria. Multivariable logistic regression analysis showed that favorable VO (OR= 2.10 [95% CI 1.39-3.16]; p<0.001) was associated with excellent vessel reperfusion during thrombectomy, regardless of good CTA collateral status (OR= 0.87 [95%CI 0.58-1.34]; p=0.48). A favorable VO profile (OR= 8.9 [95%CI 5.3-14.9]; p<0.001) and excellent vessel reperfusion status (OR = 2.7 [95%CI 1.7-4.4]; p<0.001) were independently associated with good functional outcome adjusted for age, sex, glucose, tPA administration, good CTA collateral status and presentation NIHSS.CONCLUSION: A favorable VO profile is associated with reperfusion success and good functional outcomes in patients with AIS-LVO treated by endovascular thrombectomy.
View details for DOI 10.1212/WNL.0000000000012106
View details for PubMedID 33952649
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Computed Tomography-Based Imaging Algorithms for Patient Selection in Acute Ischemic Stroke.
Neuroimaging clinics of North America
2021; 31 (2): 235–50
Abstract
Computed tomography remains the most widely used imaging modality for evaluating patients with acute ischemic stroke. Landmark trials have used computed tomography imaging to select patients for intravenous thrombolysis and endovascular treatment. This review summarizes the most important acute ischemic stroke trials, provides an outlook of ongoing studies, and proposes possible image algorithms for patient selection. Although evaluation with anatomic computed tomography imaging techniques is sufficient in early window patients, more advanced imaging techniques should be used beyond 6hours from symptoms onset to quantify the ischemic core and evaluate for the salvageable penumbra.
View details for DOI 10.1016/j.nic.2020.12.002
View details for PubMedID 33902877
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VINE Catheter for Endovascular Surgery
IEEE TRANSACTIONS ON MEDICAL ROBOTICS AND BIONICS
2021; 3 (2): 384-391
View details for DOI 10.1109/TMRB.2021.3069984
View details for Web of Science ID 000896666700010
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Venous Outflow Profiles Are Linked to Cerebral Edema Formation at Noncontrast Head CT after Treatment in Acute Ischemic Stroke Regardless of Collateral Vessel Status at CT Angiography.
Radiology
2021: 203651
Abstract
Background Ischemic lesion net water uptake (NWU) at noncontrast head CT enables quantification of cerebral edema in patients with acute ischemic stroke (AIS) due to large vessel occlusion (LVO). Purpose To assess whether favorable venous outflow (VO) profiles at CT angiography are associated with reduced NWU and good functional outcomes in patients with AIS due to LVO. Materials and Methods This multicenter retrospective cohort study evaluated consecutive patients with AIS due to LVO who underwent thrombectomy triage between January 2013 and December 2019. Arterial collateral vessel status (Tan scale) and venous output were measured at CT angiography. Venous outflow was graded with use of the cortical vein opacification score, which quantifies opacification of the vein of Labbe, sphenoparietal sinus, and superficial middle cerebral vein. Favorable VO was regarded as a score of 3-6 and unfavorable VO as a score of 0-2. NWU was determined at follow-up noncontrast CT. Multivariable regression analyses were performed to determine the association between favorable VO profiles and NWU after treatment and good functional outcome (modified Rankin Scale, ≤2). Results A total of 580 patients were included. Of the 580 patients, 231 had favorable VO (104 women; median age, 73 years [interquartile range {IQR}, 62-81 years]) and 349 had unfavorable VO (190 women; median age, 77 years [IQR, 66-84 years]). Compared with patients with unfavorable VO, those with favorable VO exhibited lower baseline National Institutes of Health Stroke Scale score (median, 12.5 [IQR, 7-17] vs 17 [IQR, 13-21]), higher Alberta Stroke Program Early CT Score (median, 9 [IQR, 7-10] vs 7 [IQR, 6-8]), and less NWU after treatment (median, 7% [IQR, 4.6%-11.5%] vs 17.9% [IQR, 12.3%-22.2%]). In a multivariable regression analysis, NWU mean difference between patients with unfavorable VO and those with favorable VO was 6.1% (95% CI: 4.9, 7.3; P < .001) regardless of arterial CT angiography collateral vessel status (b coefficient, 0.72 [95% CI: -0.59, 2.03; P = .28]). Favorable VO (odds ratio [OR]: 4.1 [95% CI: 2.2, 7.7]; P < .001) and reduced NWU after treatment (OR: 0.77 [95% CI: 0.73, 0.83]; P < .001) were independently associated with good functional outcomes. Conclusion Favorable venous outflow (VO) correlated with reduced ischemic net water uptake (NWU) after treatment. Reduced NWU and favorable VO were associated with good functional outcomes regardless of CT angiography arterial collateral vessel status. ©RSNA, 2021 Online supplemental material is available for this article.
View details for DOI 10.1148/radiol.2021203651
View details for PubMedID 33825511
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The Cerebral Collateral Cascade: Rethinking the Assessment of Vascular Pathways in Acute Ischemic Stroke Patients.
LIPPINCOTT WILLIAMS & WILKINS. 2021
View details for DOI 10.1161/str.52.suppl_1.P321
View details for Web of Science ID 000670883500438
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RAPID-LVO for Automated Detection of Intracranial Large Vessel Occlusion in Ct Angiography of the Brain.
LIPPINCOTT WILLIAMS & WILKINS. 2021
View details for DOI 10.1161/str.52.suppl_1.P337
View details for Web of Science ID 000670883500454
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Assistance From Automated ASPECTS Software Improves Reader Performance.
LIPPINCOTT WILLIAMS & WILKINS. 2021
View details for DOI 10.1161/str.52.suppl_1.P336
View details for Web of Science ID 000670883500453
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Clinical Outcomes and Identification of Patients With Persistent Penumbral Profiles Beyond 24 Hours From Last Known Well: Analysis From DEFUSE 3.
Stroke
2021: STROKEAHA120031147
Abstract
BACKGROUND AND PURPOSE: DEFUSE 3 (Endovascular Therapy Following Imaging Evaluation for Ischemic Stroke 3) infarct volumes at 24 hours did not significantly differ in the endovascular thrombectomy (EVT) versus medical management (MM) only groups. We hypothesized that this was due to underestimation of the final infarct volume among patients with persistent penumbral tissue 24 hours after randomization that subsequently progressed to infarction. We sought to assess the clinical outcomes in patients with persistent penumbral profile >24 hours from last known well and identify them based on the Persistent Penumbra Index (PPI, time-to-maximum of the residue function >6 s perfusion lesion divided by diffusion-weighted magnetic resonance imaging lesion volume on 24-hour postrandomization imaging).METHODS: Patients were stratified into those with a 24-hour postrandomization penumbral (PPI>1) versus a nonpenumbral (PPI≤1) profile. The primary outcome was 90-day-modified Rankin Scale.RESULTS: One hundred eighty-two patients were randomized (EVT: 92, MM: 90). Twenty-four-hour postrandomization time-to-maximum of the residue function and infarct volumes were assessable for 144 (EVT: 75, MM: 69). Infarct volumes did not differ between EVT and MM (median [interquartile range] mL: 35.0 [17.6-81.6] versus 41.0 [25.4-106.2], P=0.185). Thirty-two patients had persistent penumbral profile (PPI>1), of these 29 (91%) received MM. PPI was 0 (0-0.07) for EVT, and 0.77 (0.23-1.79) for MM, P<0.001. Patients with clinical-imaging mismatch (more severe strokes and smaller infarct volumes) were more likely to have persistent penumbral profile (PPI>1; adjusted odds ratio, 1.20 [1.11-1.30] for every 1-point National Institutes of Health Stroke Scale-increment and adjusted odds ratio, 0.977 [0.964-0.990] for every 10 cc smaller infarct volume, P<0.001). Patients with nonpenumbral profile (PPI≤1) had higher odds of achieving functional independence (39% versus 9%; adjusted odds ratio, 9.9[95% CI, 2.3-42.8], P=0.002), a trend towards lower mortality (12% versus 34%, P=0.002; adjusted odds ratio, 0.34 [95% CI, 0.11-1.03], P=0.057) and early clinical improvement (24-hour National Institutes of Health Stroke Scale-decrease ≥8 points or 0-1): 29% vs 9%, P=0.034) which persisted at discharge and 90-day follow-up. For a given volume, patients with PPI≤1 had significantly higher likelihood of functional independence as compared to those with PPI>1.CONCLUSIONS: Patients with persistent penumbral profile who have salvageable tissue beyond 24 hours from last known well can be identified by PPI and clinical-imaging mismatch. They have a poor prognosis and may benefit from very late window reperfusion therapies. Clinical trials in these patients are warranted.REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT02586415.
View details for DOI 10.1161/STROKEAHA.120.031147
View details for PubMedID 33563012
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Perfusion imaging-based tissue-level collaterals predict ischemic lesion net water uptake in patients with acute ischemic stroke and large vessel occlusion.
Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism
2021: 271678X21992200
Abstract
Ischemic lesion Net Water Uptake (NWU) quantifies cerebral edema formation and likely correlates with the microvascular perfusion status of patients with acute ischemic stroke due to large vessel occlusion (AIS-LVO). We hypothesized that favorable tissue-level collaterals (TLC) predict less NWU and good functional outcomes. We performed a retrospective multicenter analysis of AIS-LVO patients who underwent thrombectomy triage. TLC were measured on cerebral perfusion studies using the hypoperfusion intensity ratio (HIR; volume ratio of brain tissue with [Tmax>10sec/Tmax>6sec]); favorable TLC were regarded as HIR ≤ 0.4. NWU was determined using a quantitative densitometry approach on follow-up CT. Primary outcome was NWU. Secondary outcome was a good functional outcome (modified Rankin Scale [mRS] 0-2).580 patients met inclusion criteria. Favorable TLC (beta: 4.23, SE: 0.65; p<0.001) predicted smaller NWU after treatment. Favorable TLC (OR: 2.35, [95% CI: 1.31-4.21]; p<0.001), and decreased NWU (OR: 0.75, [95% CI: 0.70-0.79]; p<0.001) predicted good functional outcome, while controlling for age, glucose, CTA collaterals, baseline NIHSS and good vessel reperfusion status.We conclude that favorable TLC predict less ischemic lesion NWU after treatment in AIS-LVO patients. Favorable TLC and decreased NWU were independent predictors of good functional outcome.
View details for DOI 10.1177/0271678X21992200
View details for PubMedID 33557694
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Intraoperative Neuromonitoring for Cerebral Arteriovenous Malformation Embolization: A Propensity-Score Matched Retrospective Database Study.
Cureus
2021; 13 (1): e12946
Abstract
Introduction The treatment of cerebral arteriovenous malformations (AVMs) may result in neurologic morbidity, particularly when an AVM is located in or adjacent to eloquent brain regions. Intraoperative neurophysiologic monitoring (IONM) may be utilized to reduce the risk of iatrogenic injury during endovascular AVM embolization; however, IONM for endovascular AVM embolization is not ubiquitously the standard of care. Methods Admissions for AVM embolization were assessed from the IBM MarketScan Commercial and Medicare Supplemental databases (IBM Watson Health, Somers, NY). Inclusion criterion for patients was continuous enrollment six months before and after the index encounter. The use of IONM and presence of intracranial hemorrhage (ICH) were noted. Propensity-score matched cohorts with and without IONM were generated to minimize bias between treatment groups (adjusting for age, sex, and comorbidities). Results From 2007 to 2016, there were 16,279 patients diagnosed with cerebral AVM in the MarketScan database. Embolized patients were stratified into IONM and non-IONM cohorts; there were 357 patients in the IONM cohort and 1775 patients in the non-IONM cohort. Provider types were significantly different between cohorts (p<0.005). Unruptured AVMs were significantly more likely to be embolized with adjunctive IONM (17.7%) compared to ruptured AVMs (7.9%) (p<0.005). After balancing for baseline comorbidities, there were 266 patients in the IONM cohort, and 1347 patients in the non-IONM cohort. Among unruptured AVM patients, IONM was linked to a significantly shorter length of stay (2.72 versus 4.92 days; p<0.005), significantly lower rates of complications within 30 days of discharge (0.00% versus 1.88%; p=0.038), and significantly lower total payment ($40,179 versus $50,844; p<0.0001). Conclusion Endovascular embolization for unruptured AVMs performed with adjunctive IONM was associated with shorter length of stay, lower complication rates, and hospitalization costs.
View details for DOI 10.7759/cureus.12946
View details for PubMedID 33654622
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Prediction of Clinical Outcome in Patients with Large-Vessel Acute Ischemic Stroke: Performance of Machine Learning versus SPAN-100.
AJNR. American journal of neuroradiology
2021
Abstract
BACKGROUND AND PURPOSE: Traditional statistical models and pretreatment scoring systems have been used to predict the outcome for acute ischemic stroke patients (AIS). Our aim was to select the most relevant features in terms of outcome prediction on the basis of machine learning algorithms for patients with acute ischemic stroke and to compare the performance between multiple models and the Stroke Prognostication Using Age and National Institutes of Health Stroke Scale (SPAN-100) index model.MATERIALS AND METHODS: A retrospective multicenter cohort of 1431 patients with acute ischemic stroke was subdivided into recanalized and nonrecanalized patients. Extreme Gradient Boosting machine learning models were built to predict the mRS score at 90days using clinical, imaging, combined, and best-performing features. Feature selection was performed using the relative weight and frequency of occurrence in the models. The model with the best performance was compared with the SPAN-100 index model using area under the receiver operating curve analysis.RESULTS: In 3 groups of patients, the baseline NIHSS was the most significant predictor of outcome among all the parameters, with relative weights of 0.360.69; ischemic core volume on CTP ranked as the most important imaging biomarker with relative weights of 0.290.47. The model with the best-performing features had a better performance than the other machine learning models. The area under the curve of the model with the best-performing features was higher than SPAN-100 model and reached statistical significance for the total (P < .05) and the nonrecanalized patients (P < .001).CONCLUSIONS: Machine learning-based feature selection can identify parameters with higher performance in outcome prediction. Machine learning models with the best-performing features, especially advanced CTP data, had superior performance of the recovery outcome prediction for patients with stroke at admission in comparison with SPAN-100.
View details for DOI 10.3174/ajnr.A6918
View details for PubMedID 33414230
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High-Performance Automated Anterior Circulation CT Angiographic Clot Detection in Acute Stroke: A Multireader Comparison.
Radiology
2021: 202734
Abstract
Background Identification of large vessel occlusion (LVO) is critical to the management of acute ischemic stroke and prerequisite to endovascular therapy in recent trials. Increasing volumes and data complexity compel the development of fast, reliable, and automated tools for LVO detection to facilitate acute imaging triage. Purpose To investigate the performance of an anterior circulation LVO detection platform in a large mixed sample of individuals with and without LVO at cerebrovascular CT angiography (CTA). Materials and Methods In this retrospective analysis, CTA data from recent cerebrovascular trials (CRISP [ClinicalTrials.gov NCT01622517] and DASH) were enriched with local repositories from 11 worldwide sites to balance demographic and technical variables in LVO-positive and LVO-negative examinations. CTA findings were reviewed independently by two neuroradiologists from different institutions for intracranial internal carotid artery (ICA) or middle cerebral artery (MCA) M1 LVO; these observers were blinded to all clinical variables and outcomes. An automated analysis platform was developed and tested for prediction of LVO presence and location relative to reader consensus. Discordance between readers with respect to LVO presence or location was adjudicated by a blinded tertiary reader at a third institution. Sensitivity, specificity, and receiver operating characteristics were assessed by an independent statistician, and subgroup analyses were conducted. Prespecified performance thresholds were set at a lower bound of the 95% CI of sensitivity and specificity of 0.8 or greater at mean times to notification of less than 3.5 minutes. Results A total of 217 study participants (mean age, 64 years ± 16 [standard deviation]; 116 men; 109 with positive findings of LVO) were evaluated. Prespecified performance thresholds were exceeded (sensitivity, 105 of 109 [96%; 95% CI: 91, 99]; specificity, 106 of 108 [98%; 95% CI: 94, 100]). Sensitivity and specificity estimates across age, sex, location, and vendor subgroups exceeded 90%. The area under the receiver operating characteristic curve was 99% (95% CI: 97, 100). Mean processing and notification time was 3 minutes 18 seconds. Conclusion The results confirm the feasibility of fast automated high-performance detection of intracranial internal carotid artery and middle cerebral artery M1 occlusions. © RSNA, 2021 See also the editorial by Kloska in this issue.
View details for DOI 10.1148/radiol.2021202734
View details for PubMedID 33434110
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Non-contrast dual-energy CT virtual ischemia maps accurately estimate ischemic core size in large-vessel occlusive stroke.
Scientific reports
2021; 11 (1): 6745
Abstract
Dual-energy CT (DECT) material decomposition techniques may better detect edema within cerebral infarcts than conventional non-contrast CT (NCCT). This study compared if Virtual Ischemia Maps (VIM) derived from non-contrast DECT of patients with acute ischemic stroke due to large-vessel occlusion (AIS-LVO) are superior to NCCT for ischemic core estimation, compared against reference-standard DWI-MRI. Only patients whose baseline ischemic core was most likely to remain stable on follow-up MRI were included, defined as those with excellent post-thrombectomy revascularization or no perfusion mismatch. Twenty-four consecutive AIS-LVO patients with baseline non-contrast DECT, CT perfusion (CTP), and DWI-MRI were analyzed. The primary outcome measure was agreement between volumetric manually segmented VIM, NCCT, and automatically segmented CTP estimates of the ischemic core relative to manually segmented DWI volumes. Volume agreement was assessed using Bland-Altman plots and comparison of CT to DWI volume ratios. DWI volumes were better approximated by VIM than NCCT (VIM/DWI ratio 0.68 ± 0.35 vs. NCCT/DWI ratio 0.34 ± 0.35; P < 0.001) or CTP (CTP/DWI ratio 0.45 ± 0.67; P < 0.001), and VIM best correlated with DWI (rVIM = 0.90; rNCCT = 0.75; rCTP = 0.77; P < 0.001). Bland-Altman analyses indicated significantly greater agreement between DWI and VIM than NCCT core volumes (mean bias 0.60 [95%AI 0.39-0.82] vs. 0.20 [95%AI 0.11-0.30]). We conclude that DECT VIM estimates the ischemic core in AIS-LVO patients more accurately than NCCT.
View details for DOI 10.1038/s41598-021-85143-3
View details for PubMedID 33762589
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Thrombectomy for anterior circulation stroke beyond 6 h from time last known well (AURORA): a systematic review and individual patient data meta-analysis.
Lancet (London, England)
2021
Abstract
Trials examining the benefit of thrombectomy in anterior circulation proximal large vessel occlusion stroke have enrolled patients considered to have salvageable brain tissue, who were randomly assigned beyond 6 h and (depending on study protocol) up to 24 h from time last seen well. We aimed to estimate the benefit of thrombectomy overall and in prespecified subgroups through individual patient data meta-analysis.We did a systematic review and individual patient data meta-analysis between Jan 1, 2010, and March 1, 2021, of randomised controlled trials of endovascular stroke therapy. In the Analysis Of Pooled Data From Randomized Studies Of Thrombectomy More Than 6 Hours After Last Known Well (AURORA) collaboration, the primary outcome was disability on the modified Rankin Scale (mRS) at 90 days, analysed by ordinal logistic regression. Key safety outcomes were symptomatic intracerebral haemorrhage and mortality within 90 days.Patient level data from 505 individuals (n=266 intervention, n=239 control; mean age 68·6 years [SD 13·7], 259 [51·3%] women) were included from six trials that met inclusion criteria of 17 screened published randomised trials. Primary outcome analysis showed a benefit of thrombectomy with an unadjusted common odds ratio (OR) of 2·42 (95% CI 1·76-3·33; p<0·0001) and an adjusted common OR (for age, gender, baseline stroke severity, extent of infarction on baseline head CT, and time from onset to random assignment) of 2·54 (1·83-3·54; p<0·0001). Thrombectomy was associated with higher rates of independence in activities of daily living (mRS 0-2) than best medical therapy alone (122 [45·9%] of 266 vs 46 [19·3%] of 238; p<0·0001). No significant difference between intervention and control groups was found when analysing either 90-day mortality (44 [16·5%] of 266 vs 46 [19·3%] of 238) or symptomatic intracerebral haemorrhage (14 [5·3%] of 266 vs eight [3·3%] of 239). No heterogeneity of treatment effect was noted across subgroups defined by age, gender, baseline stroke severity, vessel occlusion site, baseline Alberta Stroke Program Early CT Score, and mode of presentation; treatment effect was stronger in patients randomly assigned within 12-24 h (common OR 5·86 [95% CI 3·14-10·94]) than those randomly assigned within 6-12 h (1·76 [1·18-2·62]; pinteraction=0·0087).These findings strengthen the evidence for benefit of endovascular thrombectomy in patients with evidence of reversible cerebral ischaemia across the 6-24 h time window and are relevant to clinical practice. Our findings suggest that in these patients, thrombectomy should not be withheld on the basis of mode of presentation or of the point in time of presentation within the 6-24 h time window.Stryker Neurovascular.
View details for DOI 10.1016/S0140-6736(21)01341-6
View details for PubMedID 34774198
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Predictors of Early and Late Infarct Growth in DEFUSE 3.
Frontiers in neurology
2021; 12: 699153
Abstract
Introduction: The goal of this study is to explore the impact of reperfusion and collateral status on infarct growth in the early and late time windows. Materials and Methods: Seventy patients from the DEFUSE 3 trial (Endovascular Therapy Following Imaging Evaluation for Ischemic Stroke) with baseline, 24-h, and late follow-up scans were evaluated. Scans were taken with DWI or CTP at time of enrollment (Baseline), with DWI or CT 24-h after enrollment (24-h), and with DWI or CT 5 days after enrollment (Late). Early infarct growth (between baseline and 24-h scans) and late infarct growth (between 24-h and late scans) was assessed for each patient. The impact of collateral and reperfusion status on infarct growth was assessed in univariate and multivariate regression. Results: The median early infarct growth was 30.3 ml (IQR 16.4-74.5) and the median late infarct growth was 6.7 ml (IQR -3.5-21.6) in the overall sample. Patients with poor collaterals showed greater early infarct growth (Median 58.5 ml; IQR 18.6-125.6) compared to patients with good collaterals (Median 28.4 ml; IQR 15.8-49.3, unadjusted p = 0.04, adjusted p = 0.06) but showed no difference in late infarct growth. In contrast, patients who reperfused showed no reduction in early infarct growth but showed reduced late infarct growth (Median 1.9 ml; IQR -6.1-8.5) compared to patients without reperfusion (Median 11.2 ml; IQR -1.1-27.2, unadjusted p < 0.01, adjusted p = 0.04). Discussion: In the DEFUSE 3 population, poor collaterals predict early infarct growth and absence of reperfusion predicts late infarct growth. These results highlight the need for timely reperfusion therapy, particularly in patients with poor collaterals and indicate that the 24-h timepoint is too early to assess the full impact of reperfusion therapy on infarct growth. Clinical Trial Registration: http://www.clinicaltrials.gov, Unique identifier [NCT02586415].
View details for DOI 10.3389/fneur.2021.699153
View details for PubMedID 34276547
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Treatment Challenges in Acute Minor Ischemic Stroke.
Frontiers in neurology
2021; 12: 723637
Abstract
Patients with acute ischemic stroke may present with minor neurologic deficits. Acute treatment decisions depend on the disability imposed by the symptoms along with radiographic features. The presence of disabling neurologic deficits warrants intravenous thrombolysis, but the indications for endovascular therapy are less defined. The degree of disability, presence of a large vessel occlusion with perfusion mismatch, and collateral circulation status may all be factors in selecting patients for endovascular treatment. Identification of patients who are at risk for neurologic deterioration is critical to preventing poor outcomes in this patient population.
View details for DOI 10.3389/fneur.2021.723637
View details for PubMedID 34557152
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Mechanical Thrombectomy With and Without Intravenous Tissue Plasminogen Activator for Acute Ischemic Stroke: A Systematic Review and Meta-Analysis Using Nested Knowledge.
Frontiers in neurology
1800; 12: 759759
Abstract
Background: Mechanical thrombectomy (MT) is now the standard-of-care treatment for acute ischemic stroke (AIS) of the anterior circulation and may be performed irrespective of intravenous tissue plasminogen activator (IV-tPA) eligibility prior to the procedure. This study aims to understand better if tPA leads to higher rates of reperfusion and improves functional outcomes in AIS patients after MT and to simultaneously evaluate the functionality and efficiency of a novel semi-automated systematic review platform. Methods: The Nested Knowledge AutoLit semi-automated systematic review platform was utilized to identify randomized control trials published between 2010 and 2021 reporting the use of mechanical thrombectomy and IV-tPA (MT+tPA) vs. MT alone for AIS treatment. The primary outcome was the rate of successful recanalization, defined as thrombolysis in cerebral infarction (TICI) scores ≥2b. Secondary outcomes included 90-day modified Rankin Scale (mRS) 0-2, 90-day mortality, distal embolization to new territory, and symptomatic intracranial hemorrhage (sICH). A separate random effects model was fit for each outcome measure. Results: We subjectively found Nested Knowledge to be highly streamlined and effective at sourcing the correct literature. Four studies with 1,633 patients, 816 in the MT+tPA arm and 817 in the MT arm, were included in the meta-analysis. In each study, patient populations consisted of only tPA-eligible patients and all imaging and clinical outcomes were adjudicated by an independent and blinded core laboratory. Compared to MT alone, patients treated with MT+tPA had higher odds of eTICI ≥2b (OR = 1.34 [95% CI: 1.10; 1.63]). However, there were no statistically significant differences in the rates of 90-day mRS 0-2 (OR = 0.98 [95% CI: 0.77; 1.24]), 90-day mortality (OR = 0.94 [95% CI: 0.67; 1.32]), distal emboli (OR = 0.94 [95% CI: 0.25; 3.60]), or sICH (OR = 1.17 [95% CI: 0.80; 1.72]). Conclusions: Administering tPA prior to MT may improve the rates of recanalization compared to MT alone in tPA-eligible patients being treated for AIS, but a corresponding improvement in functional and safety outcomes was not present in this review. Further studies looking at the role of tPA before mechanical thrombectomy in different cohorts of patients could better clarify the role of tPA in the treatment protocol for AIS.
View details for DOI 10.3389/fneur.2021.759759
View details for PubMedID 34975722
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Quality of Life in Physical, Social, and Cognitive Domains Improves With Endovascular Therapy in the DEFUSE 3 Trial.
Stroke
2021: STROKEAHA120031490
Abstract
The DEFUSE 3 (Endovascular Therapy Following Imaging Evaluation for Ischemic Stroke 3) randomized clinical trial demonstrated the efficacy of endovascular therapy in treating ischemic stroke 6 to 16 hours after onset, resulting in better functional outcomes than standard medical therapy alone. The objective of this secondary analysis is to analyze the effect of late-window endovascular treatment of ischemic stroke on quality of life (QoL) outcomes.Patients (n=182) who presented between 6 and 16 hours after they were last known to be well with acute anterior circulation ischemic stroke were randomized to endovascular thrombectomy plus standard medical therapy or standard medical therapy alone and followed-up through 90 days poststroke. QoL at day 90 was assessed with the QoL in Neurological Disorders measurement tool.Of the 146 subjects alive at day 90, 136 (95%) filled out QoL in Neurological Disorders short forms. Patients treated with endovascular therapy had better QoL scores in each domain: mobility, social participation, cognitive function, and depression (P<0.01 for all). Variables other than endovascular therapy that were independently associated with better QoL included lower baseline National Institutes of Health Stroke Scale, younger age, and male sex. The degree to which the modified Rankin Scale captures differences in QoL between patients varied by domain; the modified Rankin Scale score accounted for a high proportion of the variability in mobility (Rs2=0.82), a moderate proportion in social participation (Rs2=0.62), and a low proportion in cognition (Rs2=0.31) and depression (Rs2=0.19).Patients treated with endovascular therapy 6 to 16 hours after stroke have better QoL than patients treated with medical therapy alone, including better mobility, more social participation, superior cognition, and less depression. The modified Rankin Scale fails to capture patients' outcomes in cognition and depression, which should therefore be assessed with dedicated QoL tools.URL: https://www.clinicaltrials.gov. Unique identifier: NCT02586415.
View details for DOI 10.1161/STROKEAHA.120.031490
View details for PubMedID 33596675
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Impact of Clot Shape on Successful M1 Endovascular Reperfusion.
Frontiers in neurology
2021; 12: 642877
Abstract
Objectives: The susceptibility-vessel-sign (SVS) allows thrombus visualization, length estimation and composition, and it may impact reperfusion during mechanical thrombectomy (MT). SVS can also describe thrombus shape in the occluded artery: in the straight M1-segment (S-shaped), or in an angulated/traversing a bifurcation segment (A-shaped). We determined whether SVS clot shape influenced reperfusion and outcomes after MT for proximal middle-cerebral-artery (M1) occlusions. Methods: Between May 2015 and March 2018, consecutive patients who underwent MT at one comprehensive stroke center and who had a baseline MRI with a T2* sequence were included. Clinical, procedural and radiographic data, including clot shape on SVS [angulated/bifurcation (A-SVS) vs. straight (S-SVS)] and length were assessed. Primary outcome was successful reperfusion (TICI 2b-3). Secondary outcome were MT complication rates, MT reperfusion time, and clinical outcome at 90-days. Predictors of outcome were assessed with univariate and multivariate analyses. Results: A total of 62 patients were included. 56% (35/62) had an A-SVS. Clots were significantly longer in the A-SVS group (19 mm vs. 8 mm p = 0.0002). Groups were otherwise well-matched with regard to baseline characteristics. There was a significantly lower rate of successful reperfusion in the A-SVS cohort (83%) compared to the S-SVS cohort (96%) in multivariable analysis [OR 0.04 (95% CI, 0.002-0.58), p = 0.02]. There was no significant difference in long term clinical outcome between groups. Conclusion: Clot shape as determined on T2* imaging, in patients presenting with M1 occlusion appears to be a predictor of successful reperfusion after MT. Angulated and bifurcating clots are associated with poorer rates of successful reperfusion.
View details for DOI 10.3389/fneur.2021.642877
View details for PubMedID 33597919
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The Promise of Dual-Energy CT in Stroke and Neurovascular Imaging.
World neurosurgery
2021; 146: 379–80
View details for DOI 10.1016/j.wneu.2020.12.003
View details for PubMedID 33607724
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Favorable Venous Outflow Profiles Correlate With Favorable Tissue-Level Collaterals and Clinical Outcome.
Stroke
2021: STROKEAHA120032242
Abstract
Patients with acute ischemic stroke due to large vessel occlusion and favorable tissue-level collaterals (TLCs) likely have robust cortical venous outflow (VO). We hypothesized that favorable VO predicts robust TLC and good clinical outcomes.Multicenter retrospective cohort study of consecutive acute ischemic stroke due to large vessel occlusion patients who underwent thrombectomy triage. Included patients had interpretable prethrombectomy computed tomography, computed tomography angiography, and cerebral perfusion imaging. TLCs were measured on cerebral perfusion studies using the hypoperfusion intensity ratio (volume ratio of brain tissue with [Tmax >10 s/Tmax >6 s]). VO was determined by opacification of the vein of Labbé, sphenoparietal sinus, and superficial middle cerebral vein on computed tomography angiography as 0, not visible; 1, moderate opacification; and 2, full. Clinical and demographic data were determined from the electronic medical record. Using multivariable regression analyses, we determined the association between VO and (1) favorable TLC status (defined as hypoperfusion intensity ratio ≤0.4) and (2) good functional outcome (modified Rankin Scale score, 0-2).Six hundred forty-nine patients met inclusion criteria. Patients with favorable VO were younger (median age, 72 [interquartile range (IQR), 62-80] versus 77 [IQR, 66-84] years), had a lower baseline National Institutes of Health Stroke Scale (median, 12 [IQR, 7-17] versus 19 [IQR, 13-20]), and had a higher Alberta Stroke Program Early Computed Tomography Score (median, 9 [IQR, 7-10] versus 7 [IQR, 6-9]). Favorable VO strongly predicted favorable TLC (odds ratio, 4.5 [95% CI, 3.1-6.5]; P<0.001) in an adjusted regression analysis. Favorable VO also predicted good clinical outcome (odds ratio, 10 [95% CI, 6.2-16.0]; P<0.001), while controlling for favorable TLC, age, glucose, baseline National Institutes of Health Stroke Scale, and good vessel reperfusion status.In this selective retrospective cohort study of acute ischemic stroke due to large vessel occlusion patients undergoing thrombectomy triage, favorable VO profiles correlated with favorable TLC and were associated with good functional outcomes after treatment. Future prospective studies should independently validate our findings.
View details for DOI 10.1161/STROKEAHA.120.032242
View details for PubMedID 33682452
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Automated Cerebral Hemorrhage Detection Using RAPID.
AJNR. American journal of neuroradiology
2020
Abstract
BACKGROUND AND PURPOSE: Intracranial hemorrhage (ICH) is an important event that is diagnosed on head NCCT. Increased NCCT utilization in busy hospitals may limit timely identification of ICH. RAPID ICH is an automated hybrid 2D-3D convolutional neural network application designed to detect ICH that may allow for expedited ICH diagnosis. We determined the accuracy of RAPID ICH for ICH detection and ICH volumetric quantification on NCCT.MATERIALS AND METHODS: NCCT scans were evaluated for ICH by RAPID ICH. Consensus detection of ICH by 3 neuroradiology experts was used as the criterion standard for RAPID ICH comparison. ICH volume was also automatically determined by RAPID ICH in patients with intraparenchymal or intraventricular hemorrhage and compared with manually segmented ICH volumes by a single neuroradiology expert. ICH detection accuracy, sensitivity, specificity, positive predictive value, negative predictive value, and positive and negative likelihood ratios by RAPID ICH were determined.RESULTS: We included 308 studies. RAPID ICH correctly identified 151/158 ICH cases and 143/150 ICH-negative cases, which resulted in high sensitivity (0.956, CI: 0.911-0.978), specificity (0.953, CI: 0.907-0.977), positive predictive value (0.956, CI: 0.911-0.978), and negative predictive value (0.953, CI: 0.907-0.977) for ICH detection. The positive likelihood ratio (20.479, CI 9.928-42.245) and negative likelihood ratio (0.046, CI 0.023-0.096) for ICH detection were similarly favorable. RAPID ICH volumetric quantification for intraparenchymal and intraventricular hemorrhages strongly correlated with expert manual segmentation (correlation coefficient r=0.983); the median absolute error was 3mL.CONCLUSIONS: RAPID ICH is highly accurate in the detection of ICH and in the volumetric quantification of intraparenchymal and intraventricular hemorrhages.
View details for DOI 10.3174/ajnr.A6926
View details for PubMedID 33361378
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Renal Safety of Multimodal Brain Imaging Followed by Endovascular Therapy.
Stroke
2020: STROKEAHA120030816
Abstract
BACKGROUND AND PURPOSE: Contrast-enhanced noninvasive angiography and perfusion imaging are recommended to identify eligible patients for endovascular therapy (EVT) in extended time windows (>6 hours or wake-up). If eligible, additional intraarterial contrast exposure will occur during EVT. We aimed to study the renal safety in the DEFUSE 3 (Endovascular Therapy Following Imaging Evaluation for Ischemic Stroke) population, selected with contrast-enhanced multimodal Imaging and randomized to EVT versus medical management.METHODS: In the randomized DEFUSE 3 trial population, we compared changes in serum creatinine between baseline (before randomization) and 24 hours later. The primary outcome was the relative change in creatinine level between baseline and 24 hours in the EVT versus medical arm. The secondary outcome was a comparison between computed tomography (CT) versus magnetic resonance imaging selection in the EVT arm. The safety outcome was a comparison of the proportion of patients with criteria for contrast-associated kidney injury in the EVT versus medical arm and a comparison between CT versus magnetic resonance imaging selection in the EVT arm.RESULTS: In the DEFUSE 3 population (n=182, age 69±13, 51% female), mean creatinine decreased from a baseline of 0.98±0.33 mg/dL to 0.88±0.28 mg/dL at 24 hours (P<0.001). There was no difference in change between treatment groups: relative to baseline, there was a 6.3% reduction in the EVT group versus 9.2% in the medical group, P=0.294. Absolute decrease -0.08±0.18 in EVT versus -0.12±0.18 in medical, P=0.135; Among patients treated with EVT, there was no difference in 24-hour creatinine level changes between patients who were selected with CT angiography/CT perfusion (-0.08±0.18) versus magnetic resonance imaging (-0.07±0.19), P=0.808 or 6.8% reduction versus 4.8%, P=0.696. In the EVT arm, contrast-associated kidney injury was encountered in 4 out of 91 (4.4%) versus 2/90 (2.2%) in the medical arm P=0.682. In the EVT arm, contrast-associated kidney injury was evenly distributed between magnetic resonance imaging (1/22, 4.6%) versus CT 3 out of 69 (4.4%), P=1.0.CONCLUSIONS: Perfusion imaging before EVT was not associated with evidence of decline in renal function.REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT02586415.
View details for DOI 10.1161/STROKEAHA.120.030816
View details for PubMedID 33250038
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Computed tomography-based triage of extensive baseline infarction: ASPECTS and collaterals versus perfusion imaging for outcome prediction.
Journal of neurointerventional surgery
2020
Abstract
BACKGROUND: Patients presenting with large baseline infarctions are often excluded from mechanical thrombectomy (MT) due to uncertainty surrounding its effect on outcome. We hypothesized that computed tomography perfusion (CTP)-based selection may be predictive of functional outcome in low Alberta Stroke Program Early CT Score (ASPECTS) patients.METHODS: This was a double-center, retrospective analysis of patients presenting with ASPECTS≤5who received multimodal admission CT imaging between May 2015 and June 2020. The predicted ischemic core (pCore) was defined as a reduction in cerebral blood flow (rCBF), while mismatch volume was defined using time to maximum (Tmax). The pCore perfusion mismatch ratio (CPMR) was also calculated. These parameters (pCore, mismatch volume, and CPMR), as well as a combined radiological score consisting of ASPECTS and collateral status (ASCO score), were tested in logistic regression and receiver operating characteristic (ROC) analyses. The primary outcome was favorable modified Rankin Scale (mRS) at discharge (≤3).RESULTS: A total of 113 patients met the inclusion criteria. The median ischemic core volume was 74.1mL (IQR 43.8-121.8). The ASCO score was associated with favorable outcome at discharge (aOR 3.7, 95%CI 1.8 to 10.7, P=0.002), while no association was observed for the CTP parameters. A model including the ASCO score also had significantly higher area under the curve (AUC) values compared with the CTP-based model (0.88 vs 0.64, P=0.018).CONCLUSIONS: The ASCO score was superior to the CTP-based model for the prediction of good functional outcome and could represent a quick, practical, and easily implemented method for the selection of low ASPECTS patients most likely benefit from MT.
View details for DOI 10.1136/neurintsurg-2020-016848
View details for PubMedID 33168659
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Collateral Status in Ischemic Stroke: A Comparison of Computed Tomography Angiography, Computed Tomography Perfusion, and Digital Subtraction Angiography.
Journal of computer assisted tomography
2020; 44 (6): 984–92
Abstract
OBJECTIVE: To compare assessment of collaterals by single-phase computed tomography (CT) angiography (CTA) and CT perfusion-derived 3-phase CTA, multiphase CTA and temporal maximum-intensity projection (tMIP) images to digital subtraction angiography (DSA), and relate collateral assessments to clinical outcome in patients with acute ischemic stroke.METHODS: Consecutive acute ischemic stroke patients who underwent CT perfusion, CTA, and DSA before thrombectomy with occlusion of the internal carotid artery, the M1 or the M2 segments were included. Two observers assessed all CT images and one separate observer assessed DSA (reference standard) with static and dynamic (modified American Society of Interventional and Therapeutic Neuroradiology) collateral grading methods. Interobserver agreement and concordance were quantified with Cohen-weighted kappa and concordance correlation coefficient, respectively. Imaging assessments were related to clinical outcome (modified Rankin Scale, ≤ 2).RESULTS: Interobserver agreement (n = 101) was 0.46 (tMIP), 0.58 (3-phase CTA), 0.67 (multiphase CTA), and 0.69 (single-phase CTA) for static assessments and 0.52 (3-phase CTA) and 0.54 (multiphase CTA) for dynamic assessments. Concordance correlation coefficient (n = 80) was 0.08 (3-phase CTA), 0.09 (single-phase CTA), and 0.23 (multiphase CTA) for static assessments and 0.10 (3-phase CTA) and 0.27 (multiphase CTA) for dynamic assessments. Higher static collateral scores on multiphase CTA (odds ratio [OR], 1.7; 95% confidence interval [CI], 1.1-2.7) and tMIP images (OR, 2.0; 95% CI, 1.1-3.4) were associated with modified Rankin Scale of 2 or less as were higher modified American Society of Interventional and Therapeutic Neuroradiology scores on 3-phase CTA (OR, 1.5; 95% CI, 1.1-2.2) and multiphase CTA (OR, 1.7; 95% CI, 1.1-2.6).CONCLUSIONS: Concordance between assessments on CT and DSA was poor. Collateral status evaluated on 3-phase CTA and multiphase CTA, but not on DSA, was associated with clinical outcome.
View details for DOI 10.1097/RCT.0000000000001090
View details for PubMedID 33196604
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Efficacy and safety of embolization of dural arteriovenous fistulas via the ophthalmic artery.
Interventional neuroradiology : journal of peritherapeutic neuroradiology, surgical procedures and related neurosciences
2020: 1591019920969270
Abstract
INTRODUCTION: Dural arteriovenous fistulae (DAVF) are vascular lesions with arteriovenous shunting that may be treated with surgical obliteration or endovascular embolization. Some DAVF, such as anterior cranial fossa DAVF (AC-DAVF) derive their arterial supply from ophthalmic artery branches in nearly all cases, and trans-arterial embolization carries a risk of vision loss. We determined the efficacy and safety of trans-ophthalmic artery embolization of DAVF.MATERIALS AND METHODS: We performed a retrospective cohort study of all patients with DAVF treated by trans-ophthalmic artery embolization from 2012 to 2020. Primary outcome was angiographic cure of the DAVF. Secondary outcomes included vision loss, visual impairment, orbital cranial nerve injury, stroke, modified Rankin Scale at 90-days, and mortality.RESULTS: 12 patients met inclusion criteria (9 males; 3 females). 10 patients had AC-DAVF. Patient age was 59.7±9.5 (mean±SD) years. Patients presented with intracranial hemorrhage (4 patients), headache (4 patients), amaurosis fugax (1 patients), or were incidentally discovered (2 patients). DAVF Cognard grades were: II (1 patient), III (6 patients), and IV (5 patients). DAVF were embolized with Onyx (10 patients), nBCA glue (1 patient), and a combination of coils and Onyx (1 patient). DAVF cure was achieved in 11 patients (92%). No patients experienced vision loss, death, or permanent disability. One patient experienced a minor complication of blurry vision attributed to posterior ischemic optic neuropathy. 90-day mRS was 0 (10 patients) and 1 (2 patients).CONCLUSIONS: Trans-ophthalmic artery embolization is an effective and safe treatment for DAVF.
View details for DOI 10.1177/1591019920969270
View details for PubMedID 33106085
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Virtual monochromatic dual-energy CT reconstructions improve detection of cerebral infarct in patients with suspicion of stroke.
Neuroradiology
2020
Abstract
PURPOSE: Early infarcts are hard to diagnose on non-contrast head CT. Dual-energy CT (DECT) may potentially increase infarct differentiation. The optimal DECT settings for differentiation were identified and evaluated.METHODS: One hundred and twenty-five consecutive patients who presented with suspected acute ischemic stroke (AIS) and underwent non-contrast DECT and subsequent DWI were retrospectively identified. The DWI was used as reference standard. First, virtual monochromatic images (VMI) of 25 patients were reconstructed from 40 to 140keV and scored by two readers for acute infarct. Sensitivity, specificity, positive, and negative predictive values for infarct detection were compared and a subset of VMI energies were selected. Next, for a separate larger cohort of 100 suspected AIS patients, conventional non-contrast CT (NCT) and selected VMI were scored by two readers for the presence and location of infarct. The same statistics for infarct detection were calculated. Infarct location match was compared per vascular territory. Subgroup analyses were dichotomized by time from last-seen-well to CT imaging.RESULTS: A total of 80-90keV VMI were marginally more sensitive (36.3-37.3%) than NCT (32.4%; p>0.680), with marginally higher specificity (92.2-94.4 vs 91.1%; p>0.509) for infarct detection. Location match was superior for VMI compared with NCT (28.7-27.4 vs 19.5%; p<0.010). Within 4.5h from last-seen-well, 80keV VMI more accurately detected infarct (58.0 vs 54.0%) and localized infarcts (27.1 vs 11.9%; p=0.004) than NCT, whereas after 4.5h, 90keV VMI was more accurate (69.3 vs 66.3%).CONCLUSION: Non-contrast 80-90keV VMI best differentiates normal from infarcted brain parenchyma.
View details for DOI 10.1007/s00234-020-02492-y
View details for PubMedID 32728777
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Treatment of posterior circulation fusiform aneurysms.
Journal of neurosurgery
2020: 1–7
Abstract
OBJECTIVE: Perforator arteries, the absence of an aneurysm discrete neck, and the often-extensive nature of posterior circulation fusiform aneurysms present treatment challenges. There have been advances in microsurgical and endovascular approaches, including flow diversion, and the authors sought to review these treatments in a long-term series at their neurovascular referral center.METHODS: The authors performed a retrospective chart review from 1990 to 2018. Primary outcomes were modified Rankin Scale (mRS) scores and Glasgow Outcome Scale (GOS) scores at follow-up. The authors also examined neurological complication rates. Using regression techniques, they reviewed independent and dependent variables, including presenting features, aneurysm location and size, surgical approach, and pretreatment and posttreatment thrombosis.RESULTS: Eighty-four patients met the inclusion criteria. Their mean age was 53 years, and 49 (58%) were female. Forty-one (49%) patients presented with subarachnoid hemorrhage. Aneurysms were located on the vertebral artery (VA) or posterior inferior cerebellar artery (PICA) in 50 (60%) patients, basilar artery (BA) or vertebrobasilar junction (VBJ) in 22 (26%), and posterior cerebral artery (PCA) in 12 (14%). Thirty-one (37%) patients were treated with microsurgical and 53 (63%) with endovascular approaches. Six aneurysms were treated with endovascular flow diversion. The authors found moderate disability or better (mRS score ≤ 3) in 85% of the patients at a mean 14-month follow-up. The GOS score was ≥ 4 in 82% of the patients. The overall neurological complication rate was 12%. In the regression analysis, patients with VA or PICA aneurysms had better functional outcomes than the other groups (p < 0.001). Endovascular strategies were associated with better outcomes for BA-VBJ aneurysms (p < 0.01), but microsurgery was associated with better outcomes for VA-PICA and PCA aneurysms (p < 0.05). There were no other significant associations between patient, aneurysm characteristics, or treatment features and neurological complications (p > 0.05). Patients treated with flow diversion had more complications than those who underwent other endovascular and microsurgical strategies, but the difference was not significant in regression models.CONCLUSIONS: Posterior circulation fusiform aneurysms remain a challenging aneurysm subtype, but an interdisciplinary treatment approach can result in good outcomes. While flow diversion is a useful addition to the armamentarium, traditional endovascular and microsurgical techniques continue to offer effective options.
View details for DOI 10.3171/2020.4.JNS192838
View details for PubMedID 32707547
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Multivariable analysis on factors associated with aneurysm rupture in patients with multiple intracranial aneurysms.
Emergency radiology
2020
Abstract
PURPOSE: Multiple intracranial aneurysms (MIA) occur in one-third of patients with intracranial aneurysms (IA), and have been previously associated with an overall worse prognosis. Risk factors for IA formation and rupture in patients with a single IA are well-known. However, risk factors associated with rupture in patients with MIA have been less studied.METHODS: We performed a retrospective search of patients with MIA identified by computed tomography angiography (CTA) within a 10-year period. Patients with > 1 saccular aneurysm with size ≥ 2.0 mm were included. The location, size, number, and rupture status of the aneurysms were recorded. Patient demographics and cerebrovascular risk factors were obtained from electronic medical records. The primary endpoint of this study was to determine the association of these factors with aneurysmal rupture. The case-fatality rate was evaluated as a secondary outcome.RESULTS: Of the 2957 patients with IA in our CTA database, 425 patients were diagnosed with MIA and were therefore included in our study. A total of 1082 aneurysms were identified. Predictors of increased risk of aneurysmal rupture were age (OR 0.98, 95% CI, 0.96-0.99), size ≥ 5 mm (OR 4.4, 95% CI 2.76-7.0); and location in the anterior communicating artery complex (AcomC) (OR 2.62, 95% CI, 1.46-4.72) or posterior communicating artery (PCOM) (OR 2.66, 95% CI, 1.45-4.87).CONCLUSIONS: Younger age, aneurysm size ≥ 5 mm, and location in the AcomC and PCOM were independently associated with aneurysmal rupture in patients with MIA. Identifying these features could help recognize patients who might benefit from early intervention.
View details for DOI 10.1007/s10140-020-01790-5
View details for PubMedID 32458143
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Collateral status contributes to differences between observed and predicted 24-h infarct volumes in DEFUSE 3.
Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism
2020: 271678X20918816
Abstract
We previously demonstrated that in the DEFUSE 3 trial, the union of the baseline core and the 24-h Tmax>6s perfusion lesion predicts the infarct volume at 24h. Presently, we assessed if collateral robustness measured by the hypoperfusion intensity ratio (HIR) and cerebral blood volume (CBV) index accounts for the variance in these predictions. DEFUSE 3 patients underwent MRI/CT perfusion imaging at baseline and 24h post-randomization. We compared baseline and follow-up HIR and CBV index across subgroups stratified by differences between predicted and observed 24-h infarct volumes. Of 123 eligible patients, 34 with 24-h infarcts larger than predicted had less favorable collaterals at baseline (HIR 0.43 vs. 0.32, p=0.006; CBV Index 0.78 vs. 0.85, p=0.001) and 24h (HIR 0.56 vs. 0.07, p=0.004; CBV Index 0.47 vs. 0.73, p=0.006) compared to 71 patients with more accurate infarct volume prediction. Eighteen patients with 24-h infarcts smaller than predicted had similar baseline collateral scores but more favorable 24-h CBV indices (0.81 vs. 0.73, p=0.040). Overall, patients with 24-h infarcts larger than predicted had evidence of less favorable baseline collaterals that fail within 24h, while patients with 24-h infarcts smaller than predicted typically had favorable collaterals that persisted for 24h.
View details for DOI 10.1177/0271678X20918816
View details for PubMedID 32423329
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Endovascular Treatment of Acute Carotid Stent Occlusion: Aspiration Thrombectomy and Angioplasty.
Cureus
2020; 12 (5): e7997
Abstract
Introduction Acute carotid stent occlusion (CSO) is a rare complication of endovascular carotid stent placement that requires emergent intervention. We describe angioplasty or combined angioplasty and aspiration thrombectomy as a new endovascular technique for CSO treatment. The technique is compared to others previously described in the literature. Methods We performed a retrospective cohort study of all patients who underwent endovascular treatment (ET) of acute symptomatic CSO from January 2008 to March 2018 at our neurovascular referral center. Patient demographics, endovascular treatment details, and outcome data were determined from the electronic medical record. Primary outcome was successful stent recanalization and cerebral reperfusion (modified thrombolysis in cerebral infarction (mTICI) score IIB-III). Secondary outcomes were National Institutes of Health Stroke Scale (NIHSS) shift from presentation to discharge, mortality, and modified Rankin Scale (mRS) score at 3 months. Additionally, a literature review (years 2008-2019) was performed to characterize other techniques for ET of CSO. Results Four patients who underwent ET of acute CSO were identified. ET treatment by angioplasty (n = 1) or combined aspiration thrombectomy and angioplasty (n = 3) resulted in carotid stent recanalization in all patients. Tandem intracranial occlusions were present in three patients (75%), and successful cerebral reperfusion was achieved in all patients. Patient symptoms improved (mean NIHSS shift -5.3 ± 7.2 at discharge). One patient died of a symptomatic reperfusion hemorrhage and another died of cardiac complications by 3-month follow-up. The mRS scores of the surviving patients were 1 and 3. Previously described studies (n = 14) using different and varied techniques had moderate recanalization rates and outcomes. Conclusion Combined aspiration thrombectomy and angioplasty for the neurointerventional treatment of acute CSO leads to high rates of stent recanalization and cerebral reperfusion. The recanalization rate here is improved compared to previously reported techniques. Further multicenter studies are required to risk-stratify patients for specific ET interventions.
View details for DOI 10.7759/cureus.7997
View details for PubMedID 32523851
View details for PubMedCentralID PMC7274505
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Endovascular Treatment of Acute Carotid Stent Occlusion: Aspiration Thrombectomy and Angioplasty
CUREUS
2020; 12 (5)
View details for DOI 10.7759/cureus.7997
View details for Web of Science ID 000530650700015
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CT perfusion core and ASPECT score prediction of outcomes in DEFUSE 3.
International journal of stroke : official journal of the International Stroke Society
2020: 1747493020915141
Abstract
BACKGROUND: The role of Alberta Stroke Program Early CT Score (ASPECTS) for thrombectomy patient selection and prognostication in late time windows is unknown.AIMS: We compared baseline ASPECTS and core infarction determined by CT perfusion (CTP) as predictors of clinical outcome in the Endovascular Therapy Following Imaging Evaluation for Ischemic Stroke 3 (DEFUSE) 3 trial.METHODS: We included all DEFUSE 3 patients with baseline non-contrast CT and CTP imaging. ASPECTS and core infarction were determined by the DEFUSE 3 core laboratory. Primary outcome was functional independence (modified Rankin Scale (mRS) ≤2). Secondary outcomes included ordinal mRS shift at 90 days and final core infarction volume.RESULTS: Of the 142 patients, 85 patients (60%) had ASPECTS 8-10 and 57 (40%) had ASPECTS 5-7. Thirty-one patients (36%) with ASPECTS 8-10 and 11 patients (19%) with ASPECTS 5-7 were functionally independent at 90 days (p=0.03). In the primary and secondary logistic regression analysis, there was no difference in ordinal mRS shift (p=0.98) or functional independence (mRS≤2; p=0.36) at 90 days between ASPECTS 8-10 and ASPECTS 5-7 patients. Similarly, primary and secondary logistic regression analyses found no difference in ordinal mRS shift (p=1.0) or functional independence (mRS≤2; p=0.87) at 90 days between patients with baseline small core (<50ml) versus medium core (50-70ml).CONCLUSIONS: Higher ASPECTS (8-10) correlated with functional independence at 90 days in the DEFUSE trial. ASPECTS and core infarction volume did not modify the thrombectomy treatment effect, which indicates that patients with a target mismatch profile on perfusion imaging should undergo thrombectomy regardless of ASPECTS or core infarction volume in late time windows.
View details for DOI 10.1177/1747493020915141
View details for PubMedID 32233746
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Comparison of Tmax values between full- and half-dose gadolinium perfusion studies.
Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism
2020: 271678X20914537
View details for DOI 10.1177/0271678X20914537
View details for PubMedID 32208802
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Safety and Effectiveness of Neuro-thrombectomy on Single compared to Biplane Angiography Systems.
Scientific reports
2020; 10 (1): 4470
Abstract
An increasing number of centers not necessarily equipped with biplane (BP) angiosuites are performing mechanical thrombectomy (MT) in acute ischemic stroke patients. We assessed whether MT performed on single-plane (SP) is equivalent in terms of safety, effectiveness, radiation and contrast agent exposure. Consecutive patients treated by MT in four high volume centers between January 2014 and May 2017 were included. Demographic and MT characteristics were assessed and compared between SP and BP. Of 906 patients treated by MT, 576 (64%) were handled on a BP system. After multivariate analysis, contrast load and fluoroscopy duration were significantly lower in the BP group [100vs200mL, relative effect 0.85 (CI: 0.79-0.92), p=0.0002; 22 vs 27min, relative effect 0.84 (CI: 0.76-0.93), p=0.0008, respectively]. There was no difference in recanalization (modified Thrombolysis-In-Cerebral-Infarction 2b-3), good clinical outcome (modified Rankin Scale 0-2), complications rates, procedure duration or radiation exposure. A three-vessel diagnostic angiogram performed prior to MT led to a significant increase in procedure duration (15% increase, p=0.05), radiation exposure (33% increase, p<0.0001) and contrast load (125% increase, p<0.0001). Mechanical neuro-thrombectomy seems equally safe and effective on a single or biplane angiography system despite increased contrast load and fluoroscopy duration on the former.
View details for DOI 10.1038/s41598-020-60851-4
View details for PubMedID 32161286
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Hypoperfusion Intensity Ratio Correlates With Angiographic Collaterals In Acute Ischemic Stroke With M1 Occlusion.
European journal of neurology
2020
Abstract
PURPOSE: Among patients with an acute ischemic stroke (AIS) secondary to large-vessel-occlusion, the hypoperfusion-intensity-ratio (HIR, TMax>10 volume / TMax>6 volume) is a strong predictor of infarct growth. We studied the correlation between HIR and collaterals assessed with digital-subtraction-angiography (DSA) before thrombectomy.METHODS: Between January 2014 and March 2018, consecutive patients with an AIS and a M1 middle-cerebral-artery occlusion who underwent perfusion imaging and endovascular treatment at our center were screened. Ischemic core (mL), HIR and perfusion mismatch (TMax>6sec minus core volume) were assessed through MRI or CT perfusion. Collaterals were assessed on pre-intervention DSA using the American-Society of Interventional and Therapeutic-Neuroradiology/Society of Interventional-Radiology (ASITN/SIR) scale. Baseline clinical and perfusion characteristics were compared between patients with good (ASITN/SIR 3-4) and those with poor (ASITN/SIR 0-2) DSA collaterals. Correlation between HIR and ASITN/SIR was evaluated using Pearson's correlation. ROC analysis was performed to determine the optimal HIR threshold for the prediction of good DSA collaterals.RESULTS: Ninety-eight patients were included. 49% (48/98) had good DSA collaterals, those patients had significantly smaller hypoperfusion volumes (TMax >6sec 89mL versus 125mL; p=0.007) and perfusion mismatch volumes (72mL versus 89mL; p=0.016). HIR was significantly correlated with DSA collaterals (-0.327 [IC 95%: -0.494 to -0.138; p=0.01]). A HIR cut-off of <0.4 best predicted good DSA collaterals with an odds ratio of 4.3 (1.8-10.1) (Sensitivity=0.792, Specificity=0.560, AUC=0.708).CONCLUSION: HIR is a robust indicator of angiographic collaterals and might be used as a surrogate of collateral assessment in patients undergoing MRI. HIR<0.4 best predicted good DSA collaterals.
View details for DOI 10.1111/ene.14181
View details for PubMedID 32068938
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Collateral Status Contributes to Differences Between Observed and Predicted 24-Hour Infarct Volumes in DEFUSE 3
LIPPINCOTT WILLIAMS & WILKINS. 2020
View details for Web of Science ID 000590040201133
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Renal Safety of Multimodal Brain Imaging Followed by Endovascular Therapy
LIPPINCOTT WILLIAMS & WILKINS. 2020
View details for Web of Science ID 000590040201311
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Arterial-spin labeling MRI identifies residual cerebral arteriovenous malformation following stereotactic radiosurgery treatment
JOURNAL OF NEURORADIOLOGY
2020; 47 (1): 13–19
View details for DOI 10.1016/j.neurad.2018.12.004
View details for Web of Science ID 000515216000004
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Effect of Oxygen Extraction (Brush-Sign) on Baseline Core Infarct Depends on Collaterals (HIR).
Frontiers in neurology
2020; 11: 618765
Abstract
Objectives: Baseline-core-infarct volume is a critical factor in patient selection and outcome in acute ischemic stroke (AIS) before mechanical thrombectomy (MT). We determined whether oxygen extraction efficiency and arterial collaterals, two different physiologic components of the cerebral ischemic cascade, interacted to modulate baseline-core-infarct volume in patients with AIS-LVO undergoing MT triage. Methods: Between January 2015 and March 2018, consecutive patients with an AIS and M1 occlusion considered for MT with a baseline MRI and perfusion-imaging were included. Variables such as baseline-core-infarct volume [mL], arterial collaterals (HIR: TMax > 10 s volume/TMax > 6 s), high oxygen extraction (HOE, presence of the brush-sign on T2*) were assessed. A linear-regression was used to test the interaction of HOE and HIR with baseline-core-infarct volume, after including potential confounding variables. Results: We included 103 patients. Median age was 70 (58-78), and 63% were female. Median baseline-core-infarct volume was 32 ml (IQR 8-74.5). Seventy six patients (74%) had HOE. In a multivariate analysis both favorable HIR collaterals (p = 0.02) and HOE (p = 0.038) were associated with lower baseline-core-infarct volume. However, HOE significantly interacted with HIR (p = 0.01) to predict baseline-core-infarct volume, favorable collaterals (low HIR) with HOE was associated with small baseline-core-infarct whereas patients with poor collaterals (high HIR) and HOE had large baseline-core-infarct. Conclusion: While HOE under effective collateral blood-flow has the lowest baseline-core-infarct volume of all patients, the protective effect of HOE reverses under poor collateral blood-flow and may be a maladaptive response to ischemic stroke as measured by core infarctions in AIS-LVO patients undergoing MT triage.
View details for DOI 10.3389/fneur.2020.618765
View details for PubMedID 33488506
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Initial experience with the Scepter Mini dual-lumen balloon for transophthalmic artery embolization of anterior cranial fossa dural arteriovenous fistulae.
Journal of neurointerventional surgery
2020
Abstract
Precise delivery of liquid embolic agents (LEAs) remains a challenge in the endovascular treatment of dural arteriovenous fistulae (dAVFs) and cerebral arteriovenous malformations (cAVMs). Despite significant advances in the past decade, LEA reflux and catheter navigability remain shortcomings of current endovascular technology, particularly in small and tortuous arteries. The Scepter Mini dual-lumen balloon microcatheter aims to address these issues by decreasing the distal catheter profile (1.6 French) while allowing for a small (2.2 mm diameter) balloon at its tip.We report our initial experience with the Scepter Mini in two patients with anterior cranial fossa dAVFs that were treated with transophthalmic artery embolization.In both patients, the Scepter Mini catheter was able to be safely advanced into the distal ophthalmic artery close to the fistula site, and several centimeters past the origins of the central retinal and posterior ciliary arteries. A single Onyx injection without any reflux resulted in angiographic cure of the dAVF in both cases, and neither patient suffered any vision loss.These initial experiences suggest that the Scepter Mini represents a significant advance in the endovascular treatment of dAVFs and cAVMs and will allow for safer and more efficacious delivery of LEAs into smaller and more distal arteries while diminishing the risk of LEA reflux.
View details for DOI 10.1136/neurintsurg-2020-016013
View details for PubMedID 32434799
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Tilt-Corrected Region Boundaries May Enhance the Alberta Stroke Program Early Computed Tomography Score for Less Experienced Raters.
Journal of stroke and cerebrovascular diseases : the official journal of National Stroke Association
2020: 104820
Abstract
The Alberta Stroke Program Early Computed Tomography Score (ASPECTS) is widely used to quantify early ischemic changes in the anterior circulation but has limited inter-rater reliability.We investigated whether application of 3-dimensional boundaries outlining the ASPECTS regions improves inter-rater reliability and accuracy.We included all patients from our DEFUSE 2 database who had a pretreatment noncontrast computed tomography scan (NCCT) of acceptable quality. Six raters (2 neuroradiologists, 2 vascular neurologists, and 2 neurology residents) scored ASPECTS of each NCCT without ("CT-native") and with the superimposed boundary template ("CT-template"). Gold-standard ASPECTS were generated by the 2 neuroradiologists through joint adjudication. Inter-rater reliability and accuracy were assessed using the intraclass correlation coefficient (ICC) for full-scale agreements and Gwet's AC1 for dichotomized (ASPECTS 0-6 vs 7-10) agreements.Eighty-two patients were included. Inter-rater reliability improved with higher training level for both CT-native (ICC = .15, .31, .54 for residents, neurologists, and radiologists, respectively) and CT-template (ICC = .18, .33, .56). Use of the boundary template improved correlation with the gold-standard for one resident on full-scale agreement (ICC increased from .01 to .31, P = .01) and another resident on dichotomized agreement (AC1 increased from .36 to .64, P = .01), but resulted in no difference for other raters. The template did not improve ICC between raters of the same training level.Inter-rater reliability of ASPECTS improves with physician training level. Standardized display of ASPECTS region boundaries on NCCT does not improve inter-rater reliability but may improve accuracy for some less experienced raters.
View details for DOI 10.1016/j.jstrokecerebrovasdis.2020.104820
View details for PubMedID 32307316
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The Myelin Water Fraction Serves as a Marker for Age-Related Myelin Alterations in the Cerebral White Matter - A Multiparametric MRI Aging Study.
Frontiers in neuroscience
2020; 14: 136
Abstract
Quantitative MRI modalities, such as diffusion tensor imaging (DTI) or magnetization transfer imaging (MTI) are sensitive to the neuronal effects of aging of the cerebral white matter (WM), but lack the specificity for myelin content. Myelin water imaging (MWI) is highly specific for myelin and may be more sensitive for the detection of changes in myelin content inside the cerebral WM microstructure. In this multiparametric imaging study, we evaluated the performance of myelin water fraction (MWF) estimates as a marker for myelin alterations during normal-aging. Multiparametric MRI data derived from DTI, MTI and a novel, recently-proposed MWF-map processing and reconstruction algorithm were acquired from 54 healthy subjects (aged 18-79 years) and region-based multivariate regression analysis was performed. MWFs significantly decreased with age in most WM regions (except corticospinal tract) and changes of MWFs were associated with changes of radial diffusivity, indicating either substantial alterations or preservation of myelin content in these regions. Decreases of fractional anisotropy and magnetization transfer ratio were associated with lower MWFs in commissural fiber tracts only. Mean diffusivity had no regional effects on MWF. We conclude that MWF estimates are sensitive for the assessment of age-related myelin alterations in the cerebral WM of normal-aging brains.
View details for DOI 10.3389/fnins.2020.00136
View details for PubMedID 32153358
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Dual antiplatelet therapy after carotid artery stenting: trends and outcomes in a large national database.
Journal of neurointerventional surgery
2020
Abstract
While dual antiplatelet therapy (dAPT) is standard of care following carotid artery stenting (CAS), the optimal dAPT regimen and duration has not been established.We canvassed a large national database (IBM MarketScan) to identify patients receiving carotid endarterectomy (CEA) or CAS for treatment of ischemic stroke or carotid artery stenosis from 2007 to 2016. We performed univariable and multivariable regression methods to evaluate the impact of covariates on post-CAS stroke-free survival, including post-discharge antiplatelet therapy.A total of 79 084 patients diagnosed with ischemic stroke or carotid stenosis received CEA (71 178; 90.0%) or CAS (7906; 10.0%). After adjusting for covariates, <180 days prescribed post-CAS P2Y12-inhibition was associated with increased risk for stroke (<90 prescribed days HR=1.421, 95% CI 1.038 to 1.946; 90-179 prescribed days HR=1.484, 95% CI 1.045 to 2.106). The incidence of hemorrhagic complications was higher during the period of prescribed P2Y12-inhibition (1.16% per person-month vs 0.49% per person-month after discontinuation, P<0.001). The rate of extracranial hemorrhage was nearly six-fold higher while on dAPT (6.50% per patient-month vs 1.16% per patient-month, P<0.001), and there was a trend towards higher rate of intracranial hemorrhage that did not reach statistical significance (5.09% per patient-month vs 3.69% per patient-month, P=0.0556). Later hemorrhagic events beyond 30 days post-CAS were significantly more likely to be extracranial (P=0.028).Increased duration of post-CAS dAPT is associated with lower rates of readmissions for stroke, and with increased risk of hemorrhagic complications, particularly extracranial hemorrhage. The potential benefit of prolonging dAPT with regard to ischemic complications must be balanced with the corresponding increased risk of predominantly extracranial hemorrhagic complications.
View details for DOI 10.1136/neurintsurg-2020-016008
View details for PubMedID 32414894
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Early Head Computed Tomography Abnormalities Associated with Elevated Intracranial Pressure in Severe Traumatic Brain Injury.
Journal of neuroimaging : official journal of the American Society of Neuroimaging
2020
Abstract
Intracranial pressure (ICP) monitoring is recommended in severe traumatic brain injury (sTBI), yet invasive monitoring has risks, and many patients do not develop elevated ICP. Tools to identify patients at risk for ICP elevation are limited. We aimed to identify early radiologic biomarkers of ICP elevation.In this retrospective study, we analyzed a prospectively enrolled cohort of patients with a sTBI at an academic level 1 trauma center. Inclusion criteria were nonpenetrating TBI, age ≥16 years, Glasgow Coma Scale (GCS) score ≤8, and presence of an ICP monitor. Two independent reviewers manually evaluated 30 prespecified features on serial head computed tomography (CTs). Patient characteristics and radiologic features were correlated with elevated ICP. The primary outcome was clinically relevant ICP elevation, defined as ICP ≥ 20 mm Hg on at least 5 or more hourly recordings during postinjury days 0-7 with concurrent administration of an ICP-lowering treatment.Among 111 sTBI patients, the median GCS was 6 (interquartile range 3-8), and 45% had elevated ICP. Features associated with elevated ICP were younger age (every 10-year decrease, odds ratio [OR] 1.4), modified Fisher scale (mFS) score at 0-4 hours postinjury (every 1 point, OR 1.8), and combined volume of contusional hemorrhage and peri-hematoma edema (10 ml, OR 1.2) at 4-18 hours postinjury.Younger age, mFS score, and volume of contusion are associated with ICP elevation in patients with a sTBI. Imaging features may stratify patients by their risk of subsequent ICP elevation.
View details for DOI 10.1111/jon.12799
View details for PubMedID 33146933
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Artificial Intelligence and Stroke Imaging: A West Coast Perspective.
Neuroimaging clinics of North America
2020; 30 (4): 479–92
Abstract
Artificial intelligence (AI) advancements have significant implications for medical imaging. Stroke is the leading cause of disability and the fifth leading cause of death in the United States. AI applications for stroke imaging are a topic of intense research. AI techniques are well-suited for dealing with vast amounts of stroke imaging data and a large number of multidisciplinary approaches used in classification, risk assessment, segmentation tasks, diagnosis, prognosis, and even prediction of therapy responses. This article addresses this topic and seeks to present an overview of machine learning and/or deep learning applied to stroke imaging.
View details for DOI 10.1016/j.nic.2020.07.001
View details for PubMedID 33038998
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Direct versus indirect bypass procedure for the treatment of ischemic moyamoya disease: results of an individualized selection strategy.
Journal of neurosurgery
2020: 1–12
Abstract
The only effective treatment for ischemic moyamoya disease (iMMD) is cerebral revascularization by an extracranial to intracranial bypass. The preferred revascularization method remains controversial: direct versus indirect bypass. The purpose of this study was to test the hypothesis that method choice should be personalized based on angiographic, hemodynamic, and clinical characteristics to balance the risk of perioperative major stroke against treatment efficacy.Patients with iMMD were identified retrospectively from a prospectively maintained database. Those with mild to moderate internal carotid artery or M1 segment stenosis, preserved cerebrovascular reserve, intraoperative M4 segment anterograde flow ≥ 8 ml/min, or the absence of frequent and severe transient ischemic attacks (TIAs) or stroke had been assigned to indirect bypass. The criteria for direct bypass were severe ICA or M1 segment stenosis or occlusion, impaired cerebrovascular reserve or steal phenomenon, intraoperative M4 segment retrograde flow or anterograde flow < 8 ml/min, and the presence of frequent and severe TIAs or clinical strokes. The primary study endpoint was MRI-confirmed symptomatic stroke ≤ 7 days postoperatively resulting in a decline in the modified Rankin Scale (mRS) score from preoperatively to 6 months postoperatively. As a secondary endpoint, the authors assessed 6-month postoperative DSA-demonstrated revascularization, which was classified as < 1/3, 1/3-2/3, or > 2/3 of the middle cerebral artery territory.One hundred thirty-eight patients with iMMD affecting 195 hemispheres revascularized in the period from March 2016 to June 2018 were included in this analysis. One hundred thirty-three hemispheres were revascularized with direct bypass and 62 with indirect bypass. The perioperative stroke rate was 4.7% and 6.8% in the direct and indirect groups, respectively (p = 0.36). Degree of revascularization was higher in the direct bypass group (p = 0.03). The proportion of patients improving to an mRS score 0-1 (from preoperatively to 6 months postoperatively) tended to be higher in the direct bypass group, although the difference between the two bypass groups was not statistically significant (p = 0.27).The selective use of an indirect bypass procedure for iMMD did not decrease the perioperative stroke rate. Direct bypass provided a significantly higher degree of revascularization. The authors conclude that direct bypass is the treatment of choice for iMMD.
View details for DOI 10.3171/2020.3.JNS192847
View details for PubMedID 32534489
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Image Quality of Virtual Monochromatic Reconstructions of Noncontrast CT on a Dual-Source CT Scanner in Adult Patients.
Academic radiology
2020
Abstract
To evaluate the image quality of virtual monochromatic images (VMI) reconstructed from dual-energy dual-source noncontrast head CT with different reconstruction kernels.Twenty-five consecutive adult patients underwent noncontrast dual-energy CT. VMI were retrospectively reconstructed at 5-keV increments from 40 to 140 keV using quantitative and head kernels. CT-number, noise levels (SD), signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) in the gray and white matter and artifacts using the posterior fossa artifact index (PFAI) were evaluated.CT-number increased with decreasing VMI energy levels, and SD was lowest at 85 keV. SNR was maximized at 80 keV and 85 keV for the head and quantitative kernels, respectively. CNR was maximum at 40 keV; PFAI was lowest at 90 (head kernel) and 100 (quantitative kernel) keV. Optimal VMI image quality was significantly better than conventional CT.Optimal image quality of VMI energies can improve brain parenchymal image quality compared to conventional CT but are reconstruction kernel dependent and depend on indication for performing noncontrast CT.
View details for DOI 10.1016/j.acra.2020.05.038
View details for PubMedID 32616420
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What predicts poor outcome after successful thrombectomy in late time windows?
Journal of neurointerventional surgery
2020
Abstract
Thrombectomy for acute ischemic stroke treatment leads to improved outcomes, but many patients do not achieve a good outcome despite successful reperfusion. We determined predictors of poor outcome after successful thrombectomy (TICI 2b-3) with an emphasis on modifiable factors.Patients from the randomized DEFUSE 3 trial who underwent thrombectomy with TICI 2b-3 revascularization were included. Primary outcome was a poor outcome at 90 days (modified Rankin Scale score 3-6).70 patients were included. Poor outcome patients were older (73.5 vs 66.5 years; P=0.01), more likely to be female (68% vs 39%; P=0.02), had higher NIHSS scores (20 vs 13; P<0.001), and had poor cerebral perfusion collaterals (hypoperfusion intensity ratio) (median 0.45 vs 0.38; P=0.03). Following thrombectomy, poor outcome patients had larger 24 hour' core infarctions (median 59.5 vs 29.9 mL; P=0.01), more core infarction growth (median 33.6 vs 13.4 mL; P<0.001), and more mild (65% vs 50%; P=0.02) and severe (18% vs 0%; P=0.01) reperfusion hemorrhage. In a logistic regression analysis, the presence of any reperfusion hemorrhage (OR 3.3 [95% CI, 1.67 to 5]; P=0.001), age (OR 1.1 [95% CI, 1.03 to 1.11], P=0.004), higher NIHSS (OR 1.25 [95% CI, 1.07 to 1.41], P=0.002), and time from imaging to femoral artery puncture (OR 5 [95% CI, 1.16 to 16.67], P=0.03) independently predicted poor outcomes.In late time windows, both mild and severe reperfusion hemorrhage were associated with poor outcomes. Older age, higher NIHSS, and increased time from imaging to arterial puncture were also associated with poor outcomes despite successful revascularization.https://clinicaltrials.gov/ct2/show/NCT02586415.
View details for DOI 10.1136/neurintsurg-2020-016125
View details for PubMedID 32554693
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Computed Tomography Perfusion Data for Acute Ischemic Stroke Evaluation Using Rapid Software: Pitfalls of Automated Postprocessing.
Journal of computer assisted tomography
2019
Abstract
Computed tomography perfusion (CTP) is increasingly used to determine treatment eligibility for acute ischemic stroke patients. Automated postprocessing of raw CTP data is routinely used, but it can fail. In reviewing 176 consecutive acute ischemic stroke patients, failures occurred in 20 patients (11%) during automated postprocessing by the RAPID software. Failures were caused by motion (n = 11, 73%), streak artifacts (n = 2, 13%), and poor contrast bolus arrival (n = 2, 13%). Stroke physicians should review CTP results with care before they are being integrated in their decision-making process.
View details for DOI 10.1097/RCT.0000000000000946
View details for PubMedID 31804241
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Perfusion Computed Tomography in Acute Ischemic Stroke.
Radiologic clinics of North America
2019; 57 (6): 1109–16
Abstract
Occlusion of a cervical or cerebral artery may cause acute ischemic stroke (AIS). Recent advances in AIS treatment by endovascular thrombectomy have led to more widespread use of advanced computed tomography (CT) imaging, including perfusion CT (PCT). This article reviews PCT for the evaluation of AIS patients.
View details for DOI 10.1016/j.rcl.2019.06.003
View details for PubMedID 31582038
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Comparison of MRI IVIM and MR perfusion imaging in acute ischemic stroke due to large vessel occlusion.
International journal of stroke : official journal of the International Stroke Society
2019: 1747493019873515
Abstract
PURPOSE: Intravoxel incoherent motion is a diffusion-weighted imaging magnetic resonance imaging technique that measures microvascular perfusion from a multi-b value sequence. Intravoxel incoherent motion microvascular perfusion has not been directly compared to conventional dynamic susceptibility contrast perfusion-weighted imaging in the context of acute ischemic stroke. We determined the degree of correlation between perfusion-weighted imaging and intravoxel incoherent motion parameter maps in patients with acute ischemic stroke.METHODS: We performed a retrospective cohort study of acute ischemic stroke patients undergoing thrombectomy treatment triage by magnetic resonance imaging. Intravoxel incoherent motion perfusion fraction maps were derived using two-step voxel-by-voxel post-processing. Ischemic core, penumbra, non-ischemia, and contralateral hemisphere were delineated based upon diffusion-weighted imaging and perfusion-weighted imaging using a Tmax >6s threshold. Signal intensity within different brain compartments were measured on intravoxel incoherent motion (IVIM f, IVIM D*, IVIM fD*) parametric maps and compared the differences using one-way ANOVA. Ischemic volumes were measured on perfusion-weighted imaging and intravoxel incoherent motion parametric maps. Bland-Altman analysis and voxel-based volumetric comparison were used to determine the agreements among ischemic volumes of perfusion-weighted imaging and intravoxel incoherent motion perfusion parameters. Inter-rater reliability on intravoxel incoherent motion maps was also assessed. Significance level was set at alpha<0.05.RESULTS: Twenty patients (11 males, 55%; mean age 67.1±13.8 years) were included. Vessel occlusions involved the internal carotid artery (6 patients, 30%) and M1 segment of the middle cerebral artery (14, 70%). Mean pre-treatment core infarct volume was 19.07±23.56ml. Mean pre-treatment ischemic volumes on perfusion-weighted imaging were 10.90±13.33ml (CBV), 24.83±23.08ml (CBF), 58.87±37.85ml (MTT), and 47.53±26.78ml (Tmax). Mean pre-treatment ischemic volumes on corresponding IVIM parameters were 23.20±25.63ml (IVIM f), 14.01±16.81ml (IVIM D*), and 27.41±40.01ml (IVIM fD*). IVIM f, D, and fD* demonstrated significant differences (P<0.001). The best agreement in term of ischemic volumes and voxel-based overlap was between IVIM fD* and CBF with mean volume difference of 0.5ml and mean dice similarity coefficient (DSC) of 0.630±0.136.CONCLUSION: There are moderate differences in brain perfusion assessment between intravoxel incoherent motion and perfusion-weighted imaging parametric maps, and IVIM fD* and perfusion-weighted imaging CBF show excellent agreement. Intravoxel incoherent motion is promising for cerebral perfusion assessment in acute ischemic stroke patients.
View details for DOI 10.1177/1747493019873515
View details for PubMedID 31480940
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Neuroimaging selection for thrombectomy in pediatric stroke: a single-center experience
JOURNAL OF NEUROINTERVENTIONAL SURGERY
2019; 11 (9): 940–46
View details for DOI 10.1136/neurintsurg-2019-014862
View details for Web of Science ID 000490293400019
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Endovascular versus medical therapy for large-vessel anterior occlusive stroke presenting with mild symptoms.
International journal of stroke : official journal of the International Stroke Society
2019: 1747493019873510
Abstract
BACKGROUND: Acute ischemic stroke patients with a large-vessel occlusion but mild symptoms (NIHSS≤6) pose a treatment dilemma between medical management and endovascular thrombectomy.AIMS: To evaluate the differences in clinical outcomes of endovascular thrombectomy-eligible patients with target-mismatch perfusion profiles who undergo either medical management or endovascular thrombectomy.METHODS: Forty-seven patients with acute ischemic stroke due to large-vessel occlusion, NIHSS≤6, and a target-mismatch perfusion imaging profile were included. Patients underwent medical management or endovascular thrombectomy following treating neurointerventionalist and neurologist consensus. The primary outcome measure was NIHSS shift. Secondary outcome measures were symptomatic intracranial hemorrhage, in-hospital mortality, and 90-day mRS scores. The primary intention-to-treat and as-treated analyses were compared to determine the impact of crossover patient allocation on study outcome measures.RESULTS: Forty-seven patients were included. Thirty underwent medical management (64%) and 17 underwent endovascular thrombectomy (36%). Three medical management patients underwent endovascular thrombectomy due to early clinical deterioration. Presentation NIHSS (P=0.82), NIHSS shift (P=0.62), and 90-day functional independence (mRS 0-2; P=0.25) were similar between groups. Endovascular thrombectomy patients demonstrated an increased overall rate of intracranial hemorrhage (35.3% vs. 10.0%; P=0.04), but symptomatic intracranial hemorrhage was similar between groups (P=0.25). In-hospital mortality was similar between groups (P=0.46), though all two deaths in the medical management group occurred among crossover patients. Endovascular thrombectomy patients demonstrated a longer length of stay (7.6±7.2 vs. 4.3±3.9 days; P=0.04) and a higher frequency of unfavorable discharge to a skilled-nursing facility (P=0.03) rather than home (P=0.05).CONCLUSIONS: Endovascular thrombectomy may pose an unfavorable risk-benefit profile over medical management for endovascular thrombectomy-eligible acute ischemic stroke patients with mild symptoms, which warrants a randomized trial in this subpopulation.
View details for DOI 10.1177/1747493019873510
View details for PubMedID 31474193
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Optimized Combination of b‑values for IVIM Perfusion Imaging in Acute Ischemic Stroke Patients.
Clinical neuroradiology
2019
Abstract
PURPOSE: To determine the optimal combination of low b‑values to generate perfusion information from intravoxel incoherent motion (IVIM) in patients with acute ischemic stroke (AIS) considering the time constraints for these patients.METHODS: A retrospective cohort study of AIS patients with IVIM MRI was performed. A two-step voxel-by-voxel postprocessing was used to derive IVIM perfusion fraction maps with different combinations of bvalues. Signal values within regions of ischemic core, non-infarcted ischemic hemisphere, and contralateral hemisphere were measured on IVIM (f, D*, fD*, D) parameter maps. Bland-Altman analysis and the Dice similarity coefficient were used to determine quantitative and spatial agreements between the reference standard IVIM (IVIM with 6 bvalues of 0, 50, 100, 150, 200, 1000 s/mm2) and other combinations of bvalues. Significance level was set at p <0.05.RESULTS: There were 58 patients (36males, 61.3%; mean age 70.2 ±13.4 years) included. Considering all IVIM parameters, the combination of bvalues of 0, 50, 200, 1000 was the most consistent with our reference standard on Bland-Altman analysis. The best voxel-based overlaps of ischemic regions were on IVIMD, while there were good voxel-based overlaps on IVIMf.CONCLUSION: The IVIM with these four bvalues collects diffusion and perfusion information from asingle short MRI sequence, which may have important implications for the imaging of AIS patients.
View details for DOI 10.1007/s00062-019-00817-w
View details for PubMedID 31375894
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Thrombectomy Results in Reduced Hospital Stay, More Home-Time, and More Favorable Living Situations in DEFUSE 3.
Stroke
2019: STROKEAHA119025165
Abstract
Background and Purpose- The DEFUSE 3 trial (Endovascular Therapy Following Imaging Evaluation for Ischemic Stroke) demonstrated that endovascular thrombectomy in the 6- to 16-hour time window improves functional outcomes of patients with evidence of salvageable tissue on baseline computed tomography or magnetic resonance imaging. The purpose of this study is to assess the effect of endovascular therapy on length of hospital stay, home-time during the first 3 months poststroke, and living situation poststroke in DEFUSE 3. Methods- Duration of hospital stay and home-time (number of days during the 90-day poststroke period that the patient resides in their own home or in that of a relative) were compared between treatment groups using the Wilcoxon rank-sum test. Patient living situation was assessed at discharge, 30 days, and 90 days on an ordinal 4-point scale (home, acute rehabilitation unit, institutionalized care, or hospice/death) and differences between groups were analyzed using the Cochran-Armitage trend test. Results- Median length of hospital stay was 9.1 (interquartile range, 6.2-15.0) days in the medical group versus 6.5 (interquartile range, 3.7-9.3) days in the endovascular group ( P<0.001). Median home-time during the first 90 days after stroke was 0 (interquartile range, 0-53) days in the medical group versus 55 (interquartile range, 0-83) days in the endovascular group ( P<0.001). The endovascular group had more favorable living situations at time of discharge ( P<0.001), 30 days ( P<0.001), and 90 days ( P<0.001) poststroke. Conclusions- Endovascular thrombectomy resulted in reduced hospital stay, more home-time, and more desirable living situations in the 90 days after stroke. These results provide evidence that endovascular therapy in the delayed time window can improve quality of life for stroke patients and reduce healthcare costs. Clinical Trial Registration- URL: https://www.clinicaltrials.gov . Unique identifier: NCT02586415.
View details for DOI 10.1161/STROKEAHA.119.025165
View details for PubMedID 31288666
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Outcomes of Thrombectomy in Transferred Patients With Ischemic Stroke in the Late Window: A Subanalysis From the DEFUSE 3 Trial
JAMA NEUROLOGY
2019; 76 (6): 682–89
View details for DOI 10.1001/jamaneurol.2019.0118
View details for Web of Science ID 000474834200011
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Response by de Havenon et al to Letter Regarding Article, "Results From DEFUSE 3: Good Collaterals Are Associated With Reduced Ischemic Core Growth but Not Neurologic Outcome"
STROKE
2019; 50 (6): E166
View details for DOI 10.1161/STROKEAHA.119.025713
View details for Web of Science ID 000470074200014
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Collateral blood flow measurement with intravoxel incoherent motion perfusion imaging in hyperacute brain stroke
NEUROLOGY
2019; 92 (21): E2462–E2471
View details for DOI 10.1212/WNL.0000000000007538
View details for Web of Science ID 000480767200007
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Response by Guenego and Heit to Letter Regarding Article, "Hypoperfusion Intensity Ratio Is Correlated With Patient Eligibility for Thrombectomy".
Stroke
2019: STROKEAHA119025863
View details for DOI 10.1161/STROKEAHA.119.025863
View details for PubMedID 31084321
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Response by de Havenon et al to Letter Regarding Article, "Results From DEFUSE 3: Good Collaterals Are Associated With Reduced Ischemic Core Growth but Not Neurologic Outcome".
Stroke
2019: STROKEAHA119025713
View details for PubMedID 31084323
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Rapid Neurologic Improvement Predicts Favorable Outcome 90 Days After Thrombectomy in the DEFUSE 3 Study
STROKE
2019; 50 (5): 1172–77
View details for DOI 10.1161/STROKEAHA.119.024928
View details for Web of Science ID 000469350000042
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Superselective methohexital challenge prior to intracranial endovascular embolization
JOURNAL OF CLINICAL NEUROSCIENCE
2019; 63: 68–71
View details for DOI 10.1016/j.jocn.2019.01.051
View details for Web of Science ID 000466249000013
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Collateral blood flow measurement with intravoxel incoherent motion perfusion imaging in hyperacute brain stroke.
Neurology
2019
Abstract
OBJECTIVE: To determine if intravoxel incoherent motion (IVIM) magnetic resonance perfusion can measure the quality of the collateral blood flow in the penumbra in hyperacute stroke.METHODS: A 6 b values IVIM MRI sequence was acquired in stroke patients with large vessel occlusion imaged <16 hours of last seen well. IVIM perfusion measures were evaluated in regions of interest drawn in the infarct core (D < 600 mm2/s), in the corresponding region in the contralateral hemisphere, and in the dynamic susceptibility contrast penumbra. In patients with a penumbra >15 mL, images were reviewed for the presence of a penumbra perfusion lesion on the IVIM f map, which was correlated with infarct size metrics. Statistical significance was tested using Student t test, Mann-Whitney U test, and Fisher exact test.RESULTS: A total of 34 patients were included. In the stroke core, IVIM f was significantly lower (4.6 ± 3.3%) compared to the healthy contralateral region (6.3 ± 2.2%, p < 0.001). In the 25 patients with a penumbra >15 mL, 9 patients had an IVIM penumbra perfusion lesion (56 ± 76 mL), and 16 did not. Patients with an IVIM penumbra perfusion lesion had a larger infarct core (82 ± 84 mL) at baseline, a larger infarct growth (68 ± 40 mL), and a larger final infarct size (126 ± 81 mL) on follow-up images compared to the patients without (resp. 20 ± 17 mL, p < 0.05; 13 ± 19 mL, p < 0.01; 29 ± 24 mL, p < 0.05). All IVIM penumbra perfusion lesions progressed to infarction despite thrombectomy treatment.CONCLUSIONS: IVIM is a promising tool to assess the quality of the collateral blood flow in hyperacute stroke. IVIM penumbra perfusion lesion may be a marker of nonsalvageable tissue despite treatment with thrombectomy, suggesting that the IVIM penumbra perfusion lesion might be counted to the stroke core, together with the DWI lesion.
View details for PubMedID 31019105
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Baseline Perfusion Imaging Collateral Scores Predict Infarct Growth in DEFUSE 3
LIPPINCOTT WILLIAMS & WILKINS. 2019
View details for Web of Science ID 000475965907014
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Association of Thrombectomy With Stroke Outcomes Among Patient Subgroups Secondary Analyses of the DEFUSE 3 Randomized Clinical Trial
JAMA NEUROLOGY
2019; 76 (4): 447–53
View details for DOI 10.1001/jamaneurol.2018.4587
View details for Web of Science ID 000463873600013
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Rapid Neurologic Improvement Predicts Favorable Outcome 90 Days After Thrombectomy in the DEFUSE 3 Study.
Stroke
2019: STROKEAHA119024928
Abstract
Background and Purpose- Thrombectomy in late time windows leads to improved outcomes in patients with ischemic stroke due to large vessel occlusion. We determined whether patients with rapid neurological improvement (RNI) 24 hours after thrombectomy were more likely to have a favorable clinical outcome in the DEFUSE 3 study (Endovascular Therapy Following Imaging Evaluation for Ischemic Stroke 3). Methods- All patients who underwent thrombectomy in DEFUSE 3 were included. RNI was defined as a reduction of ≥8 on the National Institutes of Health Stroke Scale or National Institutes of Health Stroke Scale zero to one 24 hours after thrombectomy. Clinical outcomes were assessed by an ordinal analysis modified Rankin Scale score and a dichotomous analysis for 90-day independence (modified Rankin Scale score, 0-2). Results- Ninety-one patients in DEFUSE 3 underwent thrombectomy with follow-up data; 31 patients (34%) experienced RNI (RNI+) after thrombectomy and 60 patients (66%) did not (RNI-). Patient demographics and stroke presentation and imaging details were similar between RNI+ and RNI- patients. Reperfusion (Thrombolysis in Cerebral Infarction 2b-3) after thrombectomy was achieved in 26 (84%) RNI+ and 43 (72%) RNI- ( P=0.2). Symptomatic intracranial hemorrhage occurred in no RNI+ and 8% of RNI- patients ( P=0.2). RNI was associated with a favorable modified Rankin Scale shift at day 90 (odds ratio, 3.8; CI, 1.7-8.6; P=0.001) and higher rates of modified Rankin Scale zero to 2 (61% versus 37%; odds ratio, 2.7; CI, 1.1-6.7; P=0.03). Mortality was 3% in RNI+ versus 18% in RNI- ( P=0.05). RNI+ patients had lower median 24-hour National Institutes of Health Stroke Scale (5 [interquartile range (IQR), 1-7] versus 13 [IQR, 7.5-21]; P<0.001), smaller 24-hour infarction volume (21 [IQR, 5-32] versus 65 [IQR, 27-145] mL; P<0.001), and less 24-hour infarct growth (8 [IQR, 1-18] versus 37 [IQR, 16-105] mL; P<0.001) compared with RNI- patients. Hospital stay was shorter in RNI+ (3.7 [IQR, 2.9-7.1] versus 7.4 [IQR, 5.2-12.1] days in RNI-; P<0.001). Conclusions- RNI following thrombectomy correlates with favorable clinical and radiographic outcomes and reduced hospital length of stay. RNI was a favorable prognostic sign following late-window thrombectomy in DEFUSE 3. Clinical Trial Registration- URL: https://www.clinicaltrials.gov . Unique identifier: NCT02586415.
View details for PubMedID 30932783
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Hypoperfusion Intensity Ratio Is Correlated With Patient Eligibility for Thrombectomy
STROKE
2019; 50 (4): 917–22
View details for DOI 10.1161/STROKEAHA.118.024134
View details for Web of Science ID 000469347900033
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Cerebral foreign body reaction due to hydrophilic polymer embolization following aneurysm treatment by pipeline flow diversion device.
Interventional neuroradiology : journal of peritherapeutic neuroradiology, surgical procedures and related neurosciences
2019: 1591019919830767
Abstract
The use of flow diverting stents for wide based, intracranial aneurysms has become an invaluable treatment option. While intracranial hemorrhage and ischemic stroke from dislodged atherosclerotic emboli are common adverse events, the potential for delayed granulomatous inflammation from possible hydrophilic polymer emboli is rarely recognized. We present a unique case in which visible chipping of the pusher wire for stent placement was observed, followed by clinical and radiographic evidence suggestive of a delayed foreign body reaction to intracranial hydrophilic polymer emboli. A 55-year-old woman underwent placement of a Pipeline embolization device for a left-sided, broad-based aneurysm at the base of the internal carotid artery and posterior communicating artery. Two months later she developed right-sided focal neurological deficits. Imaging showed ipsilateral focal edema and enhancing lesions with contrast. Although not confirmed with biopsy and histopathology, clinical and radiographic evidence suggests that this patient probably experienced a delayed foreign body reaction to hydrophilic polymer emboli from compromised procedural equipment during flow diverting stent placement. Although previously described, this is the first instance to our knowledge in whichvisible chipping of the pusher wire was observed on a Pipeline embolization device.
View details for DOI 10.1177/1591019919830767
View details for PubMedID 30922199
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Proposed achievable levels of dose and impact of dose-reduction systems for thrombectomy in acute ischemic stroke: an international, multicentric, retrospective study in 1096 patients.
European radiology
2019
Abstract
BACKGROUND: International dose reference levels are lacking for mechanical thrombectomy in acute ischemic stroke patients with large vessel occlusions. We studied whether radiation dose-reduction systems (RDS) could effectively reduce exposure and propose achievable levels.MATERIALS AND METHODS: We retrospectively included consecutive patients treated with thrombectomy on a biplane angiography system (BP) in five international, high-volume centers between January 2014 and May 2017. Institutional Review Board approvals were obtained. Technical, procedural, and clinical characteristics were assessed. Efficacy, safety, radiation dose, and contrast load were compared between angiography systems with and without RDS. Multivariate analyses were adjusted according to Bonferroni's correction. Proposed international achievable cutoff levels were set at the 75th percentile.RESULTS: Out of the 1096 thrombectomized patients, 520 (47%) were treated on a BP equipped with RDS. After multivariate analysis, RDS significantly reduced dose-area product (DAP) (91 vs 140Gycm2, relative effect 0.74 (CI 0.66; 0.83), 35% decrease, p<0.001) and air kerma (0.46 vs 0.97Gy, relative effect 0.63 (CI 0.56; 0.71), 53% decrease, p<0.001) with 75th percentile levels of 148Gycm2 and 0.73Gy, respectively. There was no difference in contrast load, rates of successful recanalization, complications, or clinical outcome.CONCLUSION: Radiation dose-reduction systems can reduce DAP and air kerma by a third and a half, respectively, without affecting thrombectomy efficacy or safety. The respective thresholds of 148Gycm2 and 0.73Gy represent achievable levels that may serve to optimize current and future radiation exposure in the setting of acute ischemic stroke treatment. As technology evolves, we expect these values to decrease.KEY POINTS: Internationally validated achievable levels may help caregivers and health authorities better assess and reduce radiation exposure of both ischemic stroke patients and treating staff during thrombectomy procedures. Radiation dose-reduction systems can reduce DAP and air kerma by a third and a half, respectively, without affecting thrombectomy efficacy or safety in the setting of acute ischemic stroke due to large vessel occlusion.
View details for DOI 10.1007/s00330-019-06062-6
View details for PubMedID 30903333
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Hypoperfusion Intensity Ratio Is Correlated With Patient Eligibility for Thrombectomy.
Stroke
2019: STROKEAHA118024134
Abstract
Background and Purpose- Hypoperfusion intensity ratio (HIR) is associated with collateral status in acute ischemic stroke patients with anterior circulation large vessel occlusion. We assessed whether HIR was correlated to patient eligibility for mechanical thrombectomy (MT). Methods- We performed a retrospective cohort study of consecutive acute ischemic stroke patients with a proximal middle cerebral artery or internal carotid artery occlusion who underwent MT triage with computed tomography or magnetic resonance perfusion imaging. Clinical data, ischemic core (mL), HIR (defined as time-to-maximum [TMax] >10 seconds/TMax >6 seconds), mismatch volume between core and penumbra, and MT details were assessed. Primary outcome was favorable HIR collateral score (HIR <0.4) between patients who underwent MT (MT+) and those who did not (MT-) according to American Heart Association guidelines both in the <6 hours and 6 to 24 hours windows. Secondary outcomes were favorable HIR score in MT- subgroups (National Institutes of Health Stroke Scale <6 versus core >70 mL) and core-penumbra mismatch volumes. Patients who did not meet guidelines were not included. Results- We included 197 patients (145 MT+ and 52 MT-). MT+ patients had a significantly lower median HIR compared with MT- patients (0.4 [interquartile range, 0.2-0.5] versus 0.6 [interquartile range, 0.5-0.8]; P<0.001) and a higher mismatch volume (96 versus 27 mL, P<0.001). Among MT- patients, 43 had a core >70 mL, and 9 had a National Institutes of Health Stroke Scale <6. MT- patients with National Institutes of Health Stroke Scale <6 had a lower HIR than MT- patients with core >70 mL (0.2 [interquartile range, 0.2-0.3] versus 0.7 [interquartile range, 0.6-0.8], P<0.001) but their HIR was not significantly different that MT+ patients. Conclusions- Patients who meet American Heart Association guidelines for thrombectomy are more likely to have favorable collaterals (low HIR). HIR may be used as a marker of eligibility for MT triage.
View details for PubMedID 30841821
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Results From DEFUSE 3 Good Collaterals Are Associated With Reduced Ischemic Core Growth but Not Neurologic Outcome
STROKE
2019; 50 (3): 632–38
View details for DOI 10.1161/STROKEAHA.118.023407
View details for Web of Science ID 000459699700024
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Ischemic Core and Hypoperfusion Volumes Correlate With Infarct Size 24 Hours After Randomization in DEFUSE 3
STROKE
2019; 50 (3): 626–31
View details for DOI 10.1161/STROKEAHA.118.023177
View details for Web of Science ID 000459699700023
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Persistent Target Mismatch Profile > 24 Hours After Stroke Onset in DEFUSE 3
STROKE
2019; 50 (3): 754–57
View details for DOI 10.1161/STROKEAHA.118.023392
View details for Web of Science ID 000459699700041
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Superselective methohexital challenge prior to intracranial endovascular embolization.
Journal of clinical neuroscience : official journal of the Neurosurgical Society of Australasia
2019
Abstract
Pharmacologic provocative testing (PT) and intraoperative neurophysiologic monitoring (IONM) both mitigate and predict risks associated with endovascular embolization procedures. We present a series of patients undergoing endovascular intracranial embolization predominantly for AVMs both under general anesthesia and awake with the use of IONM. We reviewed our database to identify all patients undergoing endovascular procedures between January 1, 2014 and January 1, 2016. Awake patients were tested with SSEP, EEG and real time neurologic examination while TcMEPs were performed in all anesthetized patients. BAEPs were performed in anesthetized patients if indicated. Methohexital was administered as an injection at a dose of 5 mg or 10 mg and repeat testing was performed if needed.Sixty-three endovascular procedures that met criteria were performed in 32 patients. 54 procedures in 28 patients were performed under general anesthesia, 9 procedures in 4 patients were performed in wakefulness. PT was negative in 61 procedures and subsequently completed embolizations without neurological sequelae. In two cases, the testing was positive and the procedure was terminated without embolization in one patient. The other patient underwent embolization at an alternative site without repeat PT. There were no new postoperative neurologic deficits after any of these procedures. Specificity of PT was 100% as none of the patients with a negative provocative test developed a new postoperative neurologic deficit after embolization. To our knowledge, this is the first review of PT with the use of neurophysiologic IONM techniques under general anesthesia. These data suggest a high specificity comparable to awake testing.
View details for PubMedID 30772199
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Persistent Target Mismatch Profile >24 Hours After Stroke Onset in DEFUSE 3.
Stroke
2019: STROKEAHA118023392
Abstract
Background and Purpose- Efficacy of endovascular thrombectomy has been demonstrated up to 24 hours after stroke onset in patients selected with perfusion imaging. We hypothesized that a persistent favorable perfusion profile exists in some patients beyond 24 hours from the onset and can be predicted by a lower baseline hypoperfusion intensity ratio, which indicates favorable collaterals. Methods- We identified control arm patients from the DEFUSE 3 trial (The Endovascular Therapy Following Imaging Evaluation for Ischemic Stroke) with a diffusion weighted imaging and perfusion magnetic resonance imaging performed 24 hours following randomization and compared imaging and clinical variables between patients with persistent mismatch versus patients who no longer had a mismatch 24 hours after randomization. Results- Eighteen percent of the control arm patients had a persistent favorable profile >38 hours after last known well time. These patients had similar baseline diffusion weighted imaging and Tmax >6 seconds volumes as patients whose initially favorable perfusion profile became unfavorable (diffusion weighted imaging lesion 7 versus 17 mL; P=0.17, Tmax >6 seconds 98 versus 100 mL; P=0.48) yet experienced less infarct growth (15 versus 59 mL; P<0.001) and had 3-fold smaller infarct volumes (15 versus 59 mL; P<0.001) 24 hours after randomization. Patients with a persistent favorable perfusion profile had a significantly lower hypoperfusion intensity ratio on baseline imaging (0.2 versus 0.4; P<0.01). Favorable clinical outcome at 90 days occurred in only 10% of the persistent mismatch patients. Conclusions- About 20% of patients with a middle cerebral artery or internal carotid artery occlusion who present in an extended time window and are not treated with thrombectomy have a persistent mismatch for at least an additional 24 hours. These patients have a favorable hypoperfusion intensity ratio at presentation, may experience delayed infarct expansion, and have poor clinical outcomes. Clinical trials are needed to determine if patients with a favorable perfusion profile benefit from reperfusion beyond 24 hours. Clinical Trial Registration- URL: https://www.clinicaltrials.gov . Unique identifier: NCT02586415.
View details for PubMedID 30735466
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Outcomes of Thrombectomy in Transferred Patients With Ischemic Stroke in the Late Window: A Subanalysis From the DEFUSE 3 Trial.
JAMA neurology
2019
Abstract
Importance: Although thrombectomy benefit was maintained in transfer patients with ischemic stroke in early-window trials, overall functional independence rates were lower in thrombectomy and medical management-only groups.Objective: To evaluate whether the imaging-based selection criteria used in the Endovascular Therapy Following Imaging Evaluation for Ischemic Stroke 3 (DEFUSE 3) trial would lead to comparable outcome rates and treatment benefits in transfer vs direct-admission patients.Design, Setting, and Participants: Subgroup analysis of DEFUSE 3, a prospective, randomized, multicenter, blinded-end point trial. Patients were enrolled between May 2016 and May 2017 and were followed up for 90 days. The trial comprised 38 stroke centers in the United States and 182 patients with stroke with a large-vessel anterior circulation occlusion and initial infarct volume of less than 70 mL, mismatch ratio of at least 1.8, and mismatch volume of at least 15 mL, treated within 6 to 16 hours from last known well. Patients were stratified based on whether they presented directly to the study site or were transferred from a primary center. Data were analyzed between July 2018 and October 2018.Interventions or Exposures: Endovascular thrombectomy plus standard medical therapy vs standard medical therapy alone.Main Outcomes and Measures: The primary outcome was the distribution of 90-day modified Rankin Scale scores.Results: Of the 296 patients who consented, 182 patients were randomized (66% were transfer patients and 34% directly presented to a study site). Median age was 71 years (interquartile range [IQR], 60-79 years) vs 70 years (IQR, 59-80 years); 69 transfer patients were women (57%) and 23 of the direct group were women (37%). Transfer patients had longer median times from last known well to study site arrival (9.43 vs 9 hours) and more favorable collateral profiles (based on hypoperfusion intensity ratio): median for transfer, 0.35 (IQR, 0.18-0.47) vs 0.42 (IQR, 0.25-0.56) for direct (P=.05). The primary outcome (90-day modified Rankin Scale score shift) did not differ in the direct vs transfer groups (direct OR, 2.9; 95% CI, 1.2-7.2; P=.01; transfer OR, 2.6; 95% CI, 1.3-4.8; P=.009). The overall functional independence rate (90-day modified Rankin Scale score 0-2) in the thrombectomy group did not differ (direct 44% vs transfer 45%) nor did the treatment effect (direct OR, 2.0; 95% CI, 0.9-4.4 vs transfer OR, 3.1; 95% CI, 1.6-6.1). Thrombectomy reperfusion rates, mortality, and symptomatic intracranial hemorrhage rates did not differ.Conclusions and Relevance: In late-window patients selected by penumbral mismatch criteria, both the favorable outcome rate and treatment effect did not decline in transfer patients. These results have health care implications indicating transferring potential candidates for late-window thrombectomy is associated with substantial clinical benefits and should be encouraged.Trial Registration: ClinicalTrials.gov identifier: NCT02586415.
View details for PubMedID 30734042
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Ischemic Core and Hypoperfusion Volumes Correlate With Infarct Size 24 Hours After Randomization in DEFUSE 3.
Stroke
2019: STROKEAHA118023177
Abstract
Background and Purpose- Accurate prediction of the subsequent infarct volume early after stroke onset helps determine appropriate interventions and prognosis. In the DEFUSE 3 trial (Endovascular Therapy Following Imaging Evaluation for Ischemic Stroke), we evaluated the accuracy of baseline ischemic core and hypoperfusion volumes for predicting infarct volume 24 hours after randomization to endovascular thrombectomy versus medical management. We also assessed if the union of baseline ischemic core and the volume of persistent hypoperfusion at 24 hours after randomization predicts infarct volume. Methods- Patients in DEFUSE 3 with computed tomography perfusion imaging or magnetic resonance diffusion weighted imaging/perfusion imaging acquired at baseline and at 24 hours after randomization were included. Ischemic core and Tmax >6s hypoperfusion volumes at baseline and follow-up were calculated using RAPID software and compared with the infarct volumes obtained 24 hours after randomization. Patients were stratified by reperfusion status for analyses. Results- Of 125 eligible patients, 59 patients with >90% reperfusion had a strong correlation between baseline ischemic core volume and infarct volume 24 hours postrandomization ( r=0.83; P<0.0001), and 14 patients with <10% reperfusion had a strong correlation between baseline Tmax >6s volume and infarct volume 24 hours postrandomization ( r=0.77; P<0.001). In the 52 patients with 10% to 90% reperfusion, as well as in all 125 patients, the union of the baseline ischemic core and the follow-up Tmax >6s perfusion volume was highly correlated with infarct volume 24 hours postrandomization (for N=125; r=0.83; P<0.0001), with a median absolute difference of 21.3 mL between observed and predicted infarct volumes. Conclusions- The union of the irreversibly injured ischemic core and persistently hypoperfused tissue volumes, as identified by computed tomography perfusion or magnetic resonance diffusion weighted imaging/perfusion, predicted infarct volume at 24 hours after randomization in DEFUSE 3 patients. Clinical Trial Registration- URL: http://www.clinicaltrials.gov . Unique identifier: NCT02586415.
View details for PubMedID 30727840
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Results From DEFUSE 3.
Stroke
2019: STROKEAHA118023407
Abstract
Background and Purpose- The effect of leptomeningeal collaterals for acute ischemic stroke patients with large vessel occlusion in the late window (>6 hours from last known normal) remains unknown. We sought to determine if collateral status on baseline computed tomography angiography impacted neurological outcome, ischemic core growth, and moderated the effect of endovascular thrombectomy in the late window. Methods- This is a prespecified analysis of DEFUSE 3 (Endovascular Therapy Following Imaging Evaluation for Ischemic Stroke). We included patients with computed tomography angiography as their baseline imaging and rated collateral status using the validated scales described by Tan and Maas. The primary outcome is functional independence (modified Rankin scale score of ≤2). Additional outcomes include the full range of the modified Rankin scale, baseline ischemic core volume, change from baseline in the ischemic core volume at 24 hours, and death at 90 days. Results- Of the 130 patients in our cohort, 33 (25%) had poor collaterals and 97 (75%) had good collaterals. There was no difference in the rate of functional independence with good versus poor collaterals in unadjusted analysis (30% versus 39%; P=0.3) or after adjustment for treatment arm (odds ratio [95% CI], 0.61 [0.26-1.45]). Good collaterals were associated with significantly smaller ischemic core volume and less ischemic core growth. The difference in the treatment effect of endovascular thrombectomy was not significant ( P=0.8). Collateral status also did not affect the rate of stroke-related death (n [%], good versus poor collaterals, 18/97 [19%] versus 8/33 [24%], P=0.5]. Conclusions- In DEFUSE 3 patients, good leptomeningeal collaterals on single phase computed tomography angiography were not predictive of functional independence or death and did not impact the treatment effect of endovascular thrombectomy. These unexpected findings require further study to confirm their validity and to better understand the role of collaterals for stroke patients with anterior circulation large vessel occlusion in the late therapeutic window. Clinical Trial Registration- URL: https://www.clinicaltrials.gov . Unique identifier: NCT02586415.
View details for PubMedID 30726184
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DEFUSE 3 Trial Outcomes not Affected by the Enrollment Rates of the Participating Centers.
LIPPINCOTT WILLIAMS & WILKINS. 2019
View details for Web of Science ID 000478733402235
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Baseline Perfusion Imaging Collateral Scores Predict Infarct Growth in DEFUSE 3
LIPPINCOTT WILLIAMS & WILKINS. 2019
View details for Web of Science ID 000478733400155
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Optimizing CT Perfusion Thresholds for Identification of Ischemic Core in Hyperacute Stroke.
LIPPINCOTT WILLIAMS & WILKINS. 2019
View details for Web of Science ID 000478733401337
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Late Window Transfer Patients had Favorable Outcomes Following Thrombectomy in DEFUSE 3
LIPPINCOTT WILLIAMS & WILKINS. 2019
View details for Web of Science ID 000478733400112
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Selection Criteria for Thrombectomy in Pediatric Stroke: A Single-Center Series
LIPPINCOTT WILLIAMS & WILKINS. 2019
View details for Web of Science ID 000478733401386
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CT Perfusion Collateral Score Predicts Which Patients Will Maintain a Penumbral Profile on MRI for Greater than 24 Hours
LIPPINCOTT WILLIAMS & WILKINS. 2019
View details for Web of Science ID 000478733400161
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Correlation between Modified Rankin Scale and Quality of Life in DEFUSE 3
LIPPINCOTT WILLIAMS & WILKINS. 2019
View details for Web of Science ID 000478733400174
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Union of Ischemic Core and Hypoperfusion Volume Correlates With 24-hour Infarct Size in DEFUSE 3
LIPPINCOTT WILLIAMS & WILKINS. 2019
View details for Web of Science ID 000478733402495
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Later Imaging More Accurately Captures Infarct Growth in DEFUSE 3
LIPPINCOTT WILLIAMS & WILKINS. 2019
View details for Web of Science ID 000478733402494
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Improved Quality of Life With Endovascular Therapy in the DEFUSE 3 Trial
LIPPINCOTT WILLIAMS & WILKINS. 2019
View details for Web of Science ID 000478733400006
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Thrombectomy Results in Reduced Hospital Stay, More Time at Home, and More Favorable Living Situations for Patients in the DEFUSE 3 Trial.
LIPPINCOTT WILLIAMS & WILKINS. 2019
View details for Web of Science ID 000478733400173
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Combination of Tmax and Relative CBV Perfusion Parameters More Accurately Predicts CTA Collaterals Than a Single Perfusion Parameter in DEFUSE 3.
LIPPINCOTT WILLIAMS & WILKINS. 2019
View details for Web of Science ID 000478733403010
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Early Dramatic Improvement on the National Institutes of Health Stroke Scale Predicts Favorable Outcome 90 Days After Thrombectomy in the DEFUSE 3 Study.
LIPPINCOTT WILLIAMS & WILKINS. 2019
View details for Web of Science ID 000478733402332
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Results From the DEFUSE 3 Trial: Good Leptomeningeal Collaterals Are Associated With Reduced Core Infarct Size but Not Improved Neurologic Outcome
LIPPINCOTT WILLIAMS & WILKINS. 2019
View details for Web of Science ID 000478733400007
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Association of Thrombectomy With Stroke Outcomes Among Patient Subgroups: Secondary Analyses of the DEFUSE 3 Randomized Clinical Trial.
JAMA neurology
2019
Abstract
Importance: The DEFUSE 3 randomized clinical trial previously demonstrated benefit of endovascular thrombectomy for acute ischemic stroke in the 6- to 16-hour time window. For treatment recommendations, it is important to know if the treatment benefit was universal.Objective: To determine the outcomes among patients who may have a reduced effect of thrombectomy, including those who are older, have milder symptoms, or present late.Design, Setting, and Participants: DEFUSE 3 was a randomized, open-label, blinded end point trial conducted from May 2016 to May 2017. This multicenter study included 38 sites in the United States. Of 296 patients who were enrolled in DEFUSE 3, 182 patients met all inclusion criteria and were randomized and included in the intention-to-treat analysis, which was conducted in August 2017. These patients had acute ischemic strokes due to an occlusion of the internal carotid artery or middle cerebral artery and evidence of salvageable tissue on perfusion computed tomography or magnetic resonance imaging. The study was stopped early for efficacy.Interventions: Endovascular thrombectomy plus medical management vs medical management alone.Main Outcomes and Measures: Functional outcome at day 90, assessed on the modified Rankin Scale. Multivariate ordinal logistic regression was used to calculate the adjusted proportional association between endovascular treatment and clinical outcome (shift in the distribution of modified Rankin Scale scores expressed as a common odds ratio) among patients of different ages, baseline stroke severities, onset-to-treatment times, locations of the arterial occlusion, and imaging modalities used to document the presence of salvageable tissue (computed tomography vs magnetic resonance imaging).Results: This study included 182 patients (median [interquartile range] age, 70 [59-80] years; median [interquartile range] National Institutes of Health Stroke Scale score, 16 [11-21], and 92 women [51%]). In the overall cohort, independent predictors of better functional outcome were younger age, lower baseline National Institutes of Health Stroke Scale score, and lower serum glucose level. The common odds ratio for improved functional outcome with endovascular therapy, adjusted for these variables, was 3.1 (95% CI, 1.8-5.4). There was no significant interaction between this treatment effect and age (P=.93), National Institutes of Health Stroke Scale score (P=.87), time to randomization (P=.56), imaging modality (P=.49), or location of the arterial occlusion (P=.54).Conclusions and Relevance: Endovascular thrombectomy, initiated up to 16 hours after last known well time in patients with salvageable tissue on perfusion imaging, benefits patients with a broad range of clinical features. Owing to the small sample size of this study, a pooled analysis of late time window endovascular stroke trials is needed to confirm these results.Trial Registration: ClinicalTrials.gov identifier: NCT02586415.
View details for PubMedID 30688974
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Thrombectomy for acute ischemic stroke in nonagenarians compared with octogenarians.
Journal of neurointerventional surgery
2019
Abstract
Multiple randomized trials have shown that endovascular thrombectomy (EVT) leads to improved outcomes in acute ischemic stroke (AIS) due to large vessel occlusion (LVO). Elderly patients were poorly represented in these trials, and the efficacy of EVT in nonagenarian patients remains uncertain.We performed a retrospective cohort study at a single center. Inclusion criteria were: age 80-99, LVO, core infarct <70 mL, and salvageable penumbra. Patients were stratified into octogenarian (80-89) and nonagenarian (90-99) cohorts. The primary outcome was the ordinal score on the modified Rankin Scale (mRS) at 90 days. Secondary outcomes included dichotomized functional outcome (mRS ≤2 vs mRS ≥3), successful revascularization, symptomatic intracranial hemorrhage (ICH), and mortality.108 patients met the inclusion criteria, including 79 octogenarians (73%) and 29 nonagenarians (27%). Nonagenarians were more likely to be female (86% vs 58%; p<0.01); there were no other differences between groups in terms of demographics, medical comorbidities, or treatment characteristics. Successful revascularization (TICI 2b-3) was achieved in 79% in both cohorts. Median mRS at 90 days was 5 in octogenarians and 6 in nonagenarians (p=0.09). Functional independence (mRS ≤2) at 90 days was achieved in 12.5% and 19.7% of nonagenarians and octogenarians, respectively (p=0.54). Symptomatic ICH occurred in 21.4% and 6.4% (p=0.03), and 90-day mortality rate was 63% and 40.9% (p=0.07) in nonagenarians and octogenarians, respectively.Nonagenarians may be at higher risk of symptomatic ICH than octogenarians, despite similar stroke- and treatment-related factors. While there was a trend towards higher mortality and worse functional outcomes in nonagenarians, the difference was not statistically significant in this relatively small retrospective study.
View details for DOI 10.1136/neurintsurg-2019-015147
View details for PubMedID 31350369
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Arterial-Spin Labeling MRI Identifies Residual Cerebral Arteriovenous Malformation Following Stereotactic Radiosurgery Treatment.
Journal of neuroradiology. Journal de neuroradiologie
2019
Abstract
Brain arteriovenous malformation (AVM) treatment by stereotactic radiosurgery (SRS) is effective, but AVM obliteration following SRS may take two years or longer. MRI with arterial spin labeling (ASL) may detect brain AVMs with high sensitivity. We determined whether brain MRI with ASL may accurately detect residual AVM following SRS treatment.We performed a retrospective cohort study of patients who underwent brain AVM evaluation by DSA between June 2010 and June 2015. Inclusion criteria were: (1) AVM treatment by SRS, (2) follow - up MRI with ASL at least 30 months after SRS, (3) DSA within 3 months of the follow-up MRI with ASL, and (4) no intervening AVM treatment between the MRI and DSA. Four neuroradiologists blindly and independently reviewed follow-up MRIs. Primary outcome measure was residual AVM indicated by abnormal venous ASL signal.15 patients (12 females, mean age 29 years) met inclusion criteria. There were three posterior fossa AVMs and 12 supratentorial AVMs. Spetzler-Martin (SM) Grades were: SM1 (8%), SM2 (33%), SM3 (17%), SM4 (25%), and SM5 (17%). DSA demonstrated residual AVM in 10 patients. The pooled sensitivity, specificity, positive predictive value, and negative predictive value of venous ASL signal for predicting residual AVM were 100% (95% CI: 0.9-1.0), 95% (95% CI: 0.7-1.0), 98% (95% CI: 0.9-1.0), and 100% (95% CI: 0.8-1.0), respectively. High inter-reader agreement as found by Fleiss' Kappa analysis (k = 0.92; 95% CI: 0.8-1.0; p < 0.0001).ASL is highly sensitive and specific in the detection of residual cerebral AVM following SRS treatment.
View details for PubMedID 30658138
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Neuroimaging selection for thrombectomy in pediatric stroke: a single-center experience.
Journal of neurointerventional surgery
2019
Abstract
The extended time window for endovascular therapy in adult stroke represents an opportunity for stroke treatment in children for whom diagnosis may be delayed. However, selection criteria for pediatric thrombectomy has not been defined.We performed a retrospective cohort study of patients aged <18 years presenting within 24 hours of acute large vessel occlusion. Patient consent was waived by our institutional IRB. Patient data derived from our institutional stroke database was compared between patients with good and poor outcome using Fisher's exact test, t-test, or Mann-Whitney U-test.Twelve children were included: 8/12 (66.7%) were female, mean age 9.7±5.0 years, median National Institutes of Health Stroke Scale (NIHSS) 11.5 (IQR 10-14). Stroke etiology was cardioembolic in 75%, dissection in 16.7%, and cryptogenic in 8.3%. For 2/5 with perfusion imaging, Tmax >4 s appeared to better correlate with NIHSS. Nine patients (75%) were treated: seven underwent thrombectomy alone; one received IV alteplase and thrombectomy, and one received IV alteplase alone. Favorable outcome was achieved in 78% of treated patients versus 0% of untreated patients (P=0.018). All untreated patients had poor outcome, with death (n=2) or severe disability (n=1) at follow-up. Among treated patients, older children (12.8±2.9 vs 4.2±5.0 years, P=0.014) and children presenting as outpatient (100% vs 0%, P=0.028) appeared to have better outcomes.Perfusion imaging is feasible in pediatric stroke and may help identify salvageable tissue in extended time windows, though penumbral thresholds may differ from adult values. Further studies are needed to define criteria for thrombectomy in this unique population.
View details for PubMedID 31097548
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Arterial Spin-Labeling MRI Identifies Hypervascular Meningiomas.
AJR. American journal of roentgenology
2019: 1–5
Abstract
OBJECTIVE. Preoperative identification of hypervascular meningiomas can potentially detect those that may benefit from presurgical embolization, which may help to minimize intraoperative blood loss. In this study, we investigate if increased blood flow within meningiomas seen on arterial spin-labeling (ASL) MRI correlates with increased tumor vascularity seen on digital subtraction angiography (DSA). MATERIALS AND METHODS. A retrospective study was performed of 39 meningiomas in 34 patients who underwent ASL MRI and DSA between January 2008 and January 2017. Two raters independently calculated normalized tumor blood flow (TBF) on postprocessed ASL images using ROI analysis. They also recorded the presence or absence of tumor blush on DSA in each case. Interrater agreement was assessed with intraclass correlation coefficient (ICC). Performance of ASL MRI to identify tumor blush was determined with area under the ROC curve (AUC). RESULTS. In 27 female and seven male patients (mean age, 62.8 years), mean normalized TBF for meningiomas with tumor blush on DSA was significantly higher than those without tumor blush (p < 0.001). Mean normalized TBF for the group with tumor blush and the group without tumor blush group was 4.7 ± 1.1 and 1.5 ± 1.1, respectively, for rater 1 and 4.9 ± 5.3 and 1.5 ± 1.1, respectively, for rater 2. ICC was excellent (0.91). AUC for using normalized TBF to identify tumor vascularity on DSA was 0.82 (95% CI, 0.72-0.91), and a normalized TBF cut point of 2.7 yielded 88% sensitivity and 67% specificity. CONCLUSION. ASL MRI shows potential as a noninvasive screening tool for identifying hypervascular meningiomas.
View details for DOI 10.2214/AJR.18.21026
View details for PubMedID 31361532
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Can diffusion- and perfusion-weighted imaging alone accurately triage anterior circulation acute ischemic stroke patients to endovascular therapy?
JOURNAL OF NEUROINTERVENTIONAL SURGERY
2018; 10 (12): 1132-+
View details for DOI 10.1136/neurintsurg-2018-013784
View details for Web of Science ID 000452800300012
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Advanced Neuroimaging of Acute Ischemic Stroke: Penumbra and Collateral Assessment.
Neuroimaging clinics of North America
2018; 28 (4): 585–97
Abstract
Acute ischemic stroke (AIS) occurs when there is a sudden loss in cerebral blood flow due to embolic or thromboembolic occlusion of a cerebral or cervical artery. Patients with AIS require emergent neuroimaging to guide treatment, which includes intravenous thrombolysis and endovascular mechanical thrombectomy (EMT). Recent advances in AIS treatment by EMT has been driven in part by advances in computed tomography (CT) and MR imaging neuroimaging evaluation of ischemic penumbra and pial collateral vessels. The authors review advanced noninvasive brain imaging by CT and MR imaging for the evaluation of AIS focusing on penumbral and collateral imaging.
View details for DOI 10.1016/j.nic.2018.06.004
View details for PubMedID 30322595
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Hypoperfusion ratio predicts infarct growth during transfer for thrombectomy
ANNALS OF NEUROLOGY
2018; 84 (4): 616–20
View details for DOI 10.1002/ana.25320
View details for Web of Science ID 000447367000015
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Consensus statement on current and emerging methods for the diagnosis and evaluation of cerebrovascular disease
JOURNAL OF CEREBRAL BLOOD FLOW AND METABOLISM
2018; 38 (9): 1391–1417
Abstract
Cerebrovascular disease (CVD) remains a leading cause of death and the leading cause of adult disability in most developed countries. This work summarizes state-of-the-art, and possible future, diagnostic and evaluation approaches in multiple stages of CVD, including (i) visualization of sub-clinical disease processes, (ii) acute stroke theranostics, and (iii) characterization of post-stroke recovery mechanisms. Underlying pathophysiology as it relates to large vessel steno-occlusive disease and the impact of this macrovascular disease on tissue-level viability, hemodynamics (cerebral blood flow, cerebral blood volume, and mean transit time), and metabolism (cerebral metabolic rate of oxygen consumption and pH) are also discussed in the context of emerging neuroimaging protocols with sensitivity to these factors. The overall purpose is to highlight advancements in stroke care and diagnostics and to provide a general overview of emerging research topics that have potential for reducing morbidity in multiple areas of CVD.
View details for PubMedID 28816594
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Positive pharmacologic provocative testing with methohexital during cerebral arteriovenous malformation embolization
CLINICAL IMAGING
2018; 51: 155–59
View details for DOI 10.1016/j.clinimag.2018.02.014
View details for Web of Science ID 000445321000022
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New developments in clinical ischemic stroke prevention and treatment and their imaging implications
JOURNAL OF CEREBRAL BLOOD FLOW AND METABOLISM
2018; 38 (9): 1533–50
View details for DOI 10.1177/0271678X17694046
View details for Web of Science ID 000443291300010
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Hypoperfusion Ratio predicts infarct growth during transfer for thrombectomy.
Annals of neurology
2018
Abstract
We hypothesized that automated assessment of collaterals on computed-tomography (CT) perfusion can predict the rate of infarct growth during transfer from a primary to a comprehensive stroke center for endovascular stroke treatment. We identified consecutive patients (N=28) and assessed their collaterals based on the hypoperfusion intensity ratio (HIR) prior to transfer. Infarct growth rate was strongly correlated with HIR (r= 0.78, p<0.001). ROC analysis identified an HIR of ≥0.5 as optimal for predicting infarct growth. Patients with HIR ≥ 0.5 had a median infarct growth rate of 10.1 mL/h (IQR: 6.4-18.4) compared with 0.9 mL/h (IQR: 0-2.8), p< 0.001) in patients with a HIR < 0.5. Patients with an HIR above ≥ 0.5 had an 83% probability of significant core growth, whereas patients with HIR <0.5 had an 88% probability of core stability. These preliminary data have the potential to guide decision making regarding whether repeat brain imaging should be performed after transfer to a comprehensive stroke center. This article is protected by copyright. All rights reserved.
View details for PubMedID 30168180
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Endovascular Treatment in the DEFUSE 3 Study.
Stroke
2018
Abstract
BACKGROUND AND PURPOSE: Endovascular therapy in an extended time window has been shown to be beneficial in selected patients. This study correlated angiographic outcomes of patients randomized to endovascular therapy with clinical and imaging outcomes in the DEFUSE 3 study (Endovascular Therapy Following Imaging Evaluation for Ischemic Stroke 3).METHODS: Angiograms were assessed for the primary arterial occlusive lesion and the modified Thrombolysis in Cerebral Infarction (TICI) score at baseline and the final modified TICI score. Clinical outcomes were assessed using an ordinal analysis of 90-day modified Rankin Scale and a dichotomous analysis for functional independence (modified Rankin Scale score of 0-2). TICI scores were correlated with outcome, types of device used for thrombectomy, and 24-hour follow-up imaging.RESULTS: TICI 2B-3 reperfusion was achieved in 70 of 92 patients (76%). TICI 2B-3 reperfusion showed a more favorable distribution of Rankin scores compared with TICI 0-2A; odds ratio, 2.77; 95% confidence interval, 1.17-6.56; P=0.019. Good functional outcome (90-day modified Rankin Scale score of 0-2) increased with better TICI scores (P=0.0028). There was less disability comparing TICI 3 patients to TICI 2B patients (P=0.037). Successful reperfusion (TICI 2B-3) was independent of the device used, the site of occlusion (internal carotid artery or M1) or adjunctive use of carotid angioplasty and stenting. Significantly less infarct growth at 24 hours was seen in TICI 3 patients compared with TICI 0-2A (P=0.0015) and TICI 2B (P=0.0002) patients.CONCLUSIONS: Thrombectomy in an extended time window demonstrates similar rates of TICI 2B-3 reperfusion to earlier time window studies. Successful reperfusion was independent of the device used, the site of occlusion or adjunctive use of carotid angioplasty and stenting. TICI 3 reperfusion was more likely to result in low rates of infarct growth at 24 hours and good functional outcome at 90 days.CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT02586415.
View details for DOI 10.1161/STROKEAHA.118.022147
View details for PubMedID 29986935
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Early Cerebral Vein After Endovascular Ischemic Stroke Treatment Predicts Symptomatic Reperfusion Hemorrhage
STROKE
2018; 49 (7): 1741–46
View details for DOI 10.1161/STROKEAHA.118.021402
View details for Web of Science ID 000436125600035
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Positive pharmacologic provocative testing with methohexital during cerebral arteriovenous malformation embolization.
Clinical imaging
2018; 51: 155–59
Abstract
A middle-aged patient underwent staged endovascular embolization of a Spetzler-Martin grade V right parietal arteriovenous malformation(AVM).In the fifth endovascular embolization, after methohexital 10 mg injection into a right posterior choroidal artery feeding the AVM nidus, there was an immediate change in the electroencephalogram (EEG) with simultaneous loss of motor evoked potentials (MEPs) in the bilateral upper and lower extremities and a delayed change in somatosensory evoked potential responses (SSEPs). No embolization was made and procedure was terminated. This case demonstrates the utility of intraoperative neurophysiologic monitoring (IONM) with pharmacologic provocative testing in predicting and mitigating the risks prior to the proposed embolization.
View details for PubMedID 29501883
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Thrombectomy for Stroke at 6 to 16 Hours with Selection by Perfusion Imaging.
The New England journal of medicine
2018; 378 (8): 708–18
Abstract
Thrombectomy is currently recommended for eligible patients with stroke who are treated within 6 hours after the onset of symptoms.We conducted a multicenter, randomized, open-label trial, with blinded outcome assessment, of thrombectomy in patients 6 to 16 hours after they were last known to be well and who had remaining ischemic brain tissue that was not yet infarcted. Patients with proximal middle-cerebral-artery or internal-carotid-artery occlusion, an initial infarct size of less than 70 ml, and a ratio of the volume of ischemic tissue on perfusion imaging to infarct volume of 1.8 or more were randomly assigned to endovascular therapy (thrombectomy) plus standard medical therapy (endovascular-therapy group) or standard medical therapy alone (medical-therapy group). The primary outcome was the ordinal score on the modified Rankin scale (range, 0 to 6, with higher scores indicating greater disability) at day 90.The trial was conducted at 38 U.S. centers and terminated early for efficacy after 182 patients had undergone randomization (92 to the endovascular-therapy group and 90 to the medical-therapy group). Endovascular therapy plus medical therapy, as compared with medical therapy alone, was associated with a favorable shift in the distribution of functional outcomes on the modified Rankin scale at 90 days (odds ratio, 2.77; P<0.001) and a higher percentage of patients who were functionally independent, defined as a score on the modified Rankin scale of 0 to 2 (45% vs. 17%, P<0.001). The 90-day mortality rate was 14% in the endovascular-therapy group and 26% in the medical-therapy group (P=0.05), and there was no significant between-group difference in the frequency of symptomatic intracranial hemorrhage (7% and 4%, respectively; P=0.75) or of serious adverse events (43% and 53%, respectively; P=0.18).Endovascular thrombectomy for ischemic stroke 6 to 16 hours after a patient was last known to be well plus standard medical therapy resulted in better functional outcomes than standard medical therapy alone among patients with proximal middle-cerebral-artery or internal-carotid-artery occlusion and a region of tissue that was ischemic but not yet infarcted. (Funded by the National Institute of Neurological Disorders and Stroke; DEFUSE 3 ClinicalTrials.gov number, NCT02586415 .).
View details for PubMedID 29364767
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Intraoperative Imaging for Arteriovenous Malformations and Dural Arteriovenous Fistulas
BRAIN ARTERIOVENOUS MALFORMATIONS AND ARTERIOVENOUS FISTULAS
2018: 67–74
View details for Web of Science ID 000568996400011
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Dual-Energy Computed Tomography Applications in Neurointervention.
Journal of computer assisted tomography
2018
Abstract
Dual-energy computed tomography (CT) combines the high spatial resolution of standard CT with the ability to improve contrast resolution, reduce artifact, and separate materials of different atomic weights and energy-based attenuation through postprocessing. We review the underlying physical principles and applications of dual-energy CT within the context of patients undergoing preprocedural and postprocedural evaluation for neurointerventional therapies. The broad imaging categories of cerebral ischemia and hemorrhage, head and neck angiography, and the spine are reviewed.
View details for PubMedID 30052616
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Neuro-Interventional Management of Acute Ischemic Stroke.
Neuroimaging clinics of North America
2018; 28 (4): 625–38
Abstract
Restoration of cerebral blood flow is the most important step in preventing irreversible damage to hypoperfused brain cells after ischemic stroke from large-vessel occlusion. For those patients who do not respond to (or are not eligible for) intravenous thrombolysis, endovascular therapy has become standard of care. A shift is currently taking place from rigid time windows for intervention (time is brain) to physiology-driven paradigms that rely heavily on neuroimaging. At this time, one can reasonably anticipate that more patients will be treated, and that outcomes will keep improving. This article discusses in detail recent advances in endovascular stroke therapy.
View details for DOI 10.1016/j.nic.2018.06.011
View details for PubMedID 30322598
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Sofia intermediate catheter and the SNAKE technique: safety and efficacy of the Sofia catheter without guidewire or microcatheter construct.
Journal of neurointerventional surgery
2018; 10 (4): 401–6
Abstract
Neurointerventional surgeries (NIS) benefit from supportive endovascular constructs. Sofia is a soft-tipped, flexible, braided single lumen intermediate catheter designed for NIS. Sofia advancement from the cervical to the intracranial circulation without a luminal guidewire or microcatheter construct has not been described.To evaluate the efficacy and safety of the new Sofia Non-wire Advancement techniKE (SNAKE) for advancement of the Sofia into the cerebral circulation.Consecutive patients who underwent NIS using Sofia were identified. Patient information, SNAKE use, and patient outcome were determined from electronic medical records. Sofia advancement to the cavernous internal carotid artery or the V2/V3 segment junction of the vertebral artery was the primary outcome measure. Secondary outcomes included arterial vasospasm and arterial dissection.263 Patients (181 females, 69%) who underwent a total of 305 NIS using Sofia were identified. SNAKE (SNAKE+) was used in 187 procedures (61%). Two hundred and ninety-three procedures (96%) were technically successful, which included 184 SNAKE+ NIS and 109 SNAKE- NIS. Primary outcome was achieved in all SNAKE+ procedures, but not in five SNAKE- procedures (2%). No arterial dissections were identified among 305 interventions. In the intracranial circulation, a single SNAKE+ patient (0.5%) had non-flow limiting arterial vasospasm involving the petrous internal carotid. Three SNAKE+ patients (1.6%) and one SNAKE- patient (0.8%) demonstrated external carotid artery branch artery vasospasm during dural arteriovenous fistula or facial arteriovenous malformation treatment.SNAKE is a safe and effective technique for Sofia advancement. Sofia is a highly effective and safe intermediate catheter for a variety of NIS.
View details for PubMedID 28768818
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Early Cerebral Vein After Endovascular Ischemic Stroke Treatment Predicts Symptomatic Reperfusion Hemorrhage.
Stroke
2018
Abstract
Parenchymal hemorrhage (PH) after endovascular mechanical thrombectomy in acute ischemic stroke leads to worse outcomes. Better clinical and imaging biomarkers of symptomatic reperfusion PH are needed to identify patients at risk. We identified clinical and imaging predictors of reperfusion PH after endovascular mechanical thrombectomy with attention to early cerebral veins (ECVs) on postreperfusion digital subtraction angiography.We performed a retrospective cohort study of consecutive acute ischemic stroke patients undergoing endovascular mechanical thrombectomy at our neurovascular referral center. Clinical and imaging characteristics were collected from patient health records, and random forest variable importance measures were used to identify predictors of symptomatic PH. Predictors of secondary outcomes, including 90-day mortality, functional dependence (modified Rankin Scale score, >2), and National Institutes of Health Stroke Scale shift, were also determined. Diagnostic test characteristics of ECV for symptomatic PH were determined using a receiver operating characteristic analysis. Differences between patients with and without symptomatic PH were assessed with Fisher exact test and the Wilcoxon rank sum (Mann-Whitney U test) test at the 0.05 significance level.Of 64 patients with anterior circulation large-vessel occlusion identified, 6 (9.4%) developed symptomatic PH. ECV was the strongest predictor of symptomatic PH with more than twice the importance of the next best predictor, male sex. Although ECV was also predictive of 90-day mortality and functional dependence, other characteristics were more important than ECV for these outcomes. The sensitivity and specificity of ECV alone for subsequent hemorrhage were both 0.83, with an area under the curve of 0.83 and 95% confidence interval of 0.66 to 1.00.ECV on postendovascular mechanical thrombectomy digital subtraction angiography is highly diagnostic of subsequent symptomatic reperfusion hemorrhage in this data set. This finding has important implications for post-treatment management of blood pressure and anticoagulation.
View details for PubMedID 29739912
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Can diffusion- and perfusion-weighted imaging alone accurately triage anterior circulation acute ischemic stroke patients to endovascular therapy?
Journal of neurointerventional surgery
2018
Abstract
Acute ischemic stroke (AIS) patients who benefit from endovascular treatment have a large vessel occlusion (LVO), small core infarction, and salvageable brain. We determined if diffusion-weighted imaging (DWI) and perfusion-weighted imaging (PWI) alone can correctly identify and localize anterior circulation LVO and accurately triage patients to endovascular thrombectomy (ET).This retrospective cohort study included patients undergoing MRI for the evaluation of AIS symptoms. DWI and PWI images alone were anonymized and scored for cerebral infarction, LVO presence and LVO location, DWI-PWI mismatch, and ET candidacy. Readers were blinded to clinical data. The primary outcome measure was accurate ET triage. Secondary outcomes were detection of LVO and LVO location.Two hundred and nineteen patients were included. Seventy-three patients (33%) underwent endovascular AIS treatment. Readers correctly and concordantly triaged 70 of 73 patients (96%) to ET (κ=0.938; P=0.855) and correctly excluded 143 of 146 patients (98%; P=0.942). DWI and PWI alone had a 95.9% sensitivity and a 98.4% specificity for accurate endovascular triage. LVO were accurately localized to the ICA/M1 segment in 65 of 68 patients (96%; κ=0.922; P=0.817) and the M2 segment in 18 of 20 patients (90%; κ=0.830; P=0.529).AIS patients with anterior circulation LVO are accurately identified using DWI and PWI alone, and LVO location may be correctly inferred from PWI. MRA omission may be considered to expedite AIS triage in hyperacute scenarios or may confidently supplant non-diagnostic or artifact-limited MRA.
View details for PubMedID 29555872
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Current Clinical State of Advanced Magnetic Resonance Imaging for Brain Tumor Diagnosis and Follow Up.
Seminars in roentgenology
2018; 53 (1): 45–61
View details for PubMedID 29405955
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Wingspan stent delivery catheter fracture and the TRAP technique for endovascular salvage.
Interventional neuroradiology : journal of peritherapeutic neuroradiology, surgical procedures and related neurosciences
2018; 24 (1): 106–10
Abstract
Background Intracranial atherosclerotic disease may result in ischemic infarction and has a high rate of recurrent ischemic strokes despite medical therapy. Patients who fail medical therapy may undergo endovascular treatment with cerebral artery angioplasty and possible Wingspan stent placement. We present a unique case of Wingspan delivery microcatheter fracture that resulted in a retained foreign body and an endovascular salvage maneuver. Case description An elderly patient presented with an acute ischemic stroke due to a severe stenosis in the proximal left middle cerebral artery (MCA). The patient failed non-invasive medical treatment and underwent endovascular treatment with angioplasty and Wingspan stent placement. Following Wingspan stent deployment, the stent delivery catheter fractured, and the retained catheter fragment resulted in MCA occlusion. The foreign body was retrieved by balloon catheter inflation within an intermediate catheter adjacent to the proximal end of the fractured catheter and removal of the entire construct (TRAP technique). Conclusions Wingspan delivery microcatheter fracture is a rare event. The TRAP technique may be used for successful retrieval of a retained foreign body.
View details for PubMedID 29125024
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Reduced Intravoxel Incoherent Motion Microvascular Perfusion Predicts Delayed Cerebral Ischemia and Vasospasm After Aneurysm Rupture.
Stroke
2018
Abstract
Proximal artery vasospasm and delayed cerebral ischemia (DCI) after cerebral aneurysm rupture result in reduced cerebral perfusion and microperfusion and significant morbidity and mortality. Intravoxel incoherent motion (IVIM) magnetic resonance imaging extracts microvascular perfusion information from a multi-b value diffusion-weighted sequence. We determined whether decreased IVIM perfusion may identify patients with proximal artery vasospasm and DCI.We performed a pilot retrospective cohort study of patients with ruptured cerebral aneurysms. Consecutive patients who underwent a brain magnetic resonance imaging with IVIM after ruptured aneurysm treatment were included. Patient demographic, treatment, imaging, and outcome data were determined by electronic medical record review. Primary outcome was DCI development with proximal artery vasospasm that required endovascular treatment. Secondary outcomes included mortality and clinical outcomes at 6 months.Sixteen patients (11 females, 69%;P=0.9) were included. There were no differences in age, neurological status, or comorbidities between patients who subsequently underwent endovascular treatment of DCI (10 patients; DCI+ group) and those who did not (6 patients; DCI- group). Compared with DCI- patients, DCI+ patients had decreased IVIM perfusion fractionf(0.09±0.03 versus 0.13±0.01;P=0.03), reduced diffusion coefficientD(0.82±0.05 versus 0.92±0.07×10-3mm2/s;P=0.003), and reduced blood flow-related parameterfD* (1.18±0.40 versus 1.83±0.40×10-3mm2/s;P=0.009). IVIM pseudodiffusion coefficientD* did not differ between DCI- (0.011±0.002) and DCI+ (0.013±0.005 mm2/s;P=0.4) patients. No differences in mortality or clinical outcome were identified.Decreased IVIM perfusion fractionfand blood flow-related parameterfD* correlate with DCI and proximal artery vasospasm development after cerebral aneurysm rupture.
View details for DOI 10.1161/STROKEAHA.117.020395
View details for PubMedID 29439196
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Reply
.
AJNR. American journal of neuroradiology
2018
View details for DOI 10.3174/ajnr.A5584
View details for PubMedID 29449284
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Ischemic Stroke Treatment Trials: Neuroimaging Advancements and Implications.
Topics in magnetic resonance imaging
2017; 26 (3): 133-139
Abstract
There have been significant advancements in the treatment of acute ischemic stroke in the last 2 decades. Recent trials have placed a significant emphasis on minimizing the time from symptom onset to stroke treatment by reperfusion therapies, which decreases the cerebral infarct volume and improves clinical outcomes. These clinical advances have paralleled and been aided by advances in neuroimaging. However, controversy remains regarding how much time should be spent on neuroimaging evaluation versus expediting patient treatment. In this review article, we examine the key endovascular stroke trials published in the past 25 years, and we briefly highlight the failures and successes of endovascular stroke trials performed in the past 4 years. We also discuss the advantages and disadvantages of using time from symptom onset versus neuroimaging in determining endovascular stroke therapy candidacy.
View details for DOI 10.1097/RMR.0000000000000118
View details for PubMedID 28277455
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Fluoroscopic C-Arm and CT-Guided Selective Radiofrequency Ablation for Trigeminal and Glossopharyngeal Facial Pain Syndromes.
Pain medicine (Malden, Mass.)
2017
Abstract
Percutaneous radiofrequency ablation (RFA) of the gasserian ganglion through the foramen ovale and the glossopharyngeal nerve at the jugular foramen is a classical approach to treating trigeminal neuralgia (TN) and glossopharyngeal neuralgia (GPN), respectively. However, it can be technically challenging with serious complications. We have thus developed a novel technique utilizing C-arm and computerized tomography (CT) guidance to block TN and GPN. Our goals were to describe a three-dimensional image-based technique to improve patient comfort and to decrease procedural time associated with needle guidance.Consecutive procedures were reviewed. Academic hospital.Three patients with classical TN and GPN and 15 patients with atypical facial pain (AFP) were treated. Numeric rating scale (NRS) scores for pain at pretreatment and at one, three, and 12 months post-treatment were recorded. The primary clinical outcome (50% or more reduction in NRS) and secondary adverse clinical outcome (hematoma, facial numbness, etc.) were monitored. We had a 100% technical success with respect to appropriate needle positioning. All three classical TN/GPN patients had both immediate and sustained pain relief. Complications were minimal. The 15 AFP patients, however, showed more variable results, with only five (33%) having sustained pain relief, while in the other 10 (67%) patients, we observed suboptimal response. We present a novel method and single-center experience with C-arm and CT-guided RFA of facial pain. Quick and accurate needle placement will help future advancements in the RFA algorithm so that more durable and consistent effects can be attained, reducing uncertainty with respect to needle placement as a confounder. The RFA procedure in our study had a satisfying effect for classical TN/GPN patients but was less successful for AFP patients, though it did mirror the results from previous studies.This study is limited by its small sample size and nonrandomized design.
View details for DOI 10.1093/pm/pnx088
View details for PubMedID 28472393
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MR Perfusion predicts angiographic vasospasm after aneurysmal subarachnoid hemorrhage
LIPPINCOTT WILLIAMS & WILKINS. 2017
View details for Web of Science ID 000577381501193
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Resting-State BOLD MRI for Perfusion and Ischemia.
Topics in magnetic resonance imaging
2017; 26 (2): 91-96
Abstract
Advanced imaging techniques including computed tomography (CT) angiography, CT perfusion, magnetic resonance (MR) angiography, MR with diffusion- and perfusion-weighted imaging, and, more recently, resting-state BOLD (Blood Oxygen Level Dependent) functional MRI (rs-fMRI) are increasingly used to evaluate patients with acute ischemic stroke. Advanced imaging allows for identification of patients with ischemic stroke and determination of the size of infarcted and potentially salvageable tissue, all of which yield crucial information for proper stroke management. The addition of rs-fMRI for ischemia adds information at the microvascular level, thereby improving the understanding of pathophysiologic mechanisms of impaired cerebral perfusion and tissue oxygenation beyond the known concepts at the macrovascular level. As such, it may further delineate functional and dysfunctional neuronal networks, guide stroke interventions, and improve prognosis and monitoring of patient outcomes.
View details for DOI 10.1097/RMR.0000000000000119
View details for PubMedID 28277456
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Guest Editorial.
Topics in magnetic resonance imaging
2017; 26 (2): 55-?
View details for DOI 10.1097/RMR.0000000000000121
View details for PubMedID 28375950
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Advanced MRI Measures of Cerebral Perfusion and Their Clinical Applications.
Topics in magnetic resonance imaging
2017; 26 (2): 83-90
Abstract
Cerebral blood flow measurement by magnetic resonance imaging perfusion (MRP) techniques is broadly applied to patients with acute ischemic stroke, vasospasm following aneurysmal subarachnoid hemorrhage, chronic arterial steno-occlusive disease, cervical atherosclerotic disease, and primary brain neoplasms. MRP may be performed using an exogenous tracer, most commonly gadolinium-based intravenous contrast, or an endogenous tracer, such as arterial spin labeling (ASL) or intravoxel incoherent motion (IVIM). Here, we review the technical basis of commonly performed MRP techniques, the interpretation of MRP imaging maps, and how MRP provides valuable clinical information in the triage of patients with cerebral disease.
View details for DOI 10.1097/RMR.0000000000000120
View details for PubMedID 28277457
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Real-Time Fluoroscopic and C-Arm Computed Tomography Evaluation of Ommaya Reservoir Integrity.
Cureus
2017; 9 (3)
Abstract
We describe a case of a 24-year-old patient with relapsed acute myelogenous leukemia involving the central nervous system. After placement of an Ommaya reservoir for intrathecal chemotherapy administration, the patient developed progressive headache, nausea, and drowsiness and was found to have an enlarging subdural collection underlying the Ommaya. To exclude leakage of the Ommaya system into the subdural space, real-time fluoroscopic and C-arm computed tomographic evaluation of the Ommaya reservoir was performed after iodinated contrast injection into the reservoir. This novel technique demonstrated complete integrity of the Ommaya reservoir without evidence of blockage or leakage of the system. The patient underwent uncomplicated evacuation of the subdural collection without replacement of the Ommaya reservoir and made an excellent recovery. This technique for real-time interrogation of the Ommaya reservoir may have additional utility in the evaluation for Ommaya reservoir dysfunction.
View details for DOI 10.7759/cureus.1097
View details for PubMedID 28413743
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Introduction.
Topics in magnetic resonance imaging : TMRI
2017
View details for DOI 10.1097/RMR.0000000000000121
View details for PubMedID 28277458
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Contemporary Imaging of Cerebral Arteriovenous Malformations.
AJR. American journal of roentgenology
2017: 1-11
Abstract
Brain arteriovenous malformation (AVM) rupture results in substantial morbidity and mortality. The goal of AVM treatment is eradication of the AVM, but the risk of treatment must be weighed against the risk of future hemorrhage.Imaging plays a vital role by providing the information necessary for AVM management. Here, we discuss the background, natural history, clinical presentation, and imaging of AVMs. In addition, we explain advances in techniques for imaging AVMs.
View details for DOI 10.2214/AJR.16.17306
View details for PubMedID 28267351
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Real-Time Fluoroscopic and C-Arm Computed Tomography Evaluation of Ommaya Reservoir Integrity
CUREUS
2017; 9 (3)
View details for DOI 10.7759/cureus.1097
View details for Web of Science ID 000453620000035
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New developments in clinical ischemic stroke prevention and treatment and their imaging implications.
Journal of cerebral blood flow and metabolism
2017: 271678X17694046-?
Abstract
Acute ischemic stroke results from blockage of a cerebral artery or impaired cerebral blood flow due to cervical or intracranial arterial stenosis. Ischemic stroke prevention seeks to minimize the risk of developing impaired cerebral perfusion by controlling vascular and cardiac disease risk factors. Similarly, ischemic stroke treatment aims to restore cerebral blood flow through recanalization of an occluded artery or dilation of a severely narrowed artery that supplies cerebral tissue. Stroke prevention and treatment are increasingly informed by imaging studies, and neurovascular and cerebral perfusion imaging has become essential in in guiding ischemic stroke prevention and treatment. Here we review the latest advances in ischemic stroke prevention and treatment with an emphasis on the neuroimaging principles emphasized in recent randomized trials. Future research directions that should be explored in ischemic stroke prevention and treatment are also discussed.
View details for DOI 10.1177/0271678X17694046
View details for PubMedID 28195500
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Patient Outcomes and Cerebral Infarction after Ruptured Anterior Communicating Artery Aneurysm Treatment.
AJNR. American journal of neuroradiology
2017; 38 (11): 2119–25
Abstract
Anterior communicating artery aneurysm rupture and treatment is associated with high rates of dependency, which are more severe after clipping compared with coiling. To determine whether ischemic injury might account for these differences, we characterized cerebral infarction burden, infarction patterns, and patient outcomes after surgical or endovascular treatment of ruptured anterior communicating artery aneurysms.We performed a retrospective cohort study of consecutive patients with ruptured anterior communicating artery aneurysms. Patient data and neuroimaging studies were reviewed. A propensity score for outcome measures was calculated to account for the nonrandom assignment to treatment. Primary outcome was the frequency of frontal lobe and striatum ischemic injury. Secondary outcomes were patient mortality and clinical outcome at discharge and at 3 months.Coiled patients were older (median, 55 versus 50 years;P= .03), presented with a worse clinical status (60% with Hunt and Hess Score >2 versus 34% in clipped patients;P= .02), had a higher modified Fisher grade (P= .01), and were more likely to present with intraventricular hemorrhage (78% versus 56%;P= .03). Ischemic frontal lobe infarction (OR, 2.9; 95% CI, 1.1-8.4;P= .03) and recurrent artery of Heubner infarction (OR, 20.9; 95% CI, 3.5-403.7;P< .001) were more common in clipped patients. Clipped patients were more likely to be functionally dependent at discharge (OR, 3.2;P= .05) compared with coiled patients. Mortality and clinical outcome at 3 months were similar between coiled and clipped patients.Frontal lobe and recurrent artery of Heubner infarctions are more common after surgical clipping of ruptured anterior communicating artery aneurysms, and are associated with poorer clinical outcomes at discharge.
View details for PubMedID 28882863
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Pipeline embolization device retraction and foreshortening after internal carotid artery blister aneurysm treatment.
Interventional neuroradiology : journal of peritherapeutic neuroradiology, surgical procedures and related neurosciences
2017; 23 (6): 614–19
Abstract
Background Subarachnoid hemorrhage (SAH) secondary to rupture of a blister aneurysm (BA) results in high morbidity and mortality. Endovascular treatment with the pipeline embolization device (PED) has been described as a new treatment strategy for these lesions. We present the first reported case of PED retraction and foreshortening after treatment of a ruptured internal carotid artery (ICA) BA. Case description A middle-aged patient presented with SAH secondary to ICA BA rupture. The patient was treated with telescoping PED placement across the BA. After 5 days from treatment, the patient developed a new SAH due to re-rupture of the BA. Digital subtraction angiography revealed an increase in caliber of the supraclinoid ICA with associated retraction and foreshortening of the PED that resulted in aneurysm uncovering and growth. Conclusions PED should be oversized during ruptured BA treatment to prevent device retraction and aneurysm regrowth. Frequent imaging follow up after BA treatment with PED is warranted to ensure aneurysm occlusion.
View details for PubMedID 28758549
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Clinical and Arterial Spin Labeling Brain MRI Features of Transitional Venous Anomalies.
Journal of neuroimaging : official journal of the American Society of Neuroimaging
2017
Abstract
Transitional venous anomalies (TVAs) are rare cerebrovascular lesions that resemble developmental venous anomalies (DVAs), but demonstrate early arteriovenous shunting on digital subtraction angiography (DSA) without the parenchymal nidus of arteriovenous malformations (AVMs). We investigate whether arterial spin labeling (ASL) magnetic resonance imaging (MRI) can distinguish brain TVAs from DVAs and guide their clinical management.We conducted a single-center retrospective review of patients with brain parenchymal DVA-like lesions with increased ASL signal on MRI. Clinical histories and follow-up information were obtained. Two readers assessed ASL signal location relative to the vascular lesion on MRI and, if available, the presence of arteriovenous shunting on DSA.Thirty patients with DVA-like lesions with increased ASL signal were identified. Clinical symptoms prompted MRI evaluation in 83%. Symptoms did not localize to the venous anomaly in 90%. Ten percent presented with acute symptoms, only one of whom presented with hemorrhage. ASL signal in relation to the venous anomaly was identified in: 50% in the adjacent parenchyma, 33% in the lesion, 7% in a distal draining vein/sinus, and 10% in at least two of these sites. Follow-up DSA confirmed arteriovenous shunting in 71% of ASL-positive venous anomalies. Interrater agreement was very good (κ = .81-1.0, P < .001).A DVA-like lesion with increased ASL signal likely represents a TVA with arteriovenous shunting. Our study indicates that these lesions are usually incidentally detected and have a lower risk of hemorrhage than AVMs. ASL-MRI may be a useful tool to identify TVAs and guide further management of patients with TVAs.
View details for PubMedID 29205641
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Imaging of Intracranial Hemorrhage.
Journal of stroke
2017; 19 (1): 11-27
Abstract
Intracranial hemorrhage is common and is caused by diverse pathology, including trauma, hypertension, cerebral amyloid angiopathy, hemorrhagic conversion of ischemic infarction, cerebral aneurysms, cerebral arteriovenous malformations, dural arteriovenous fistula, vasculitis, and venous sinus thrombosis, among other causes. Neuroimaging is essential for the treating physician to identify the cause of hemorrhage and to understand the location and severity of hemorrhage, the risk of impending cerebral injury, and to guide often emergent patient treatment. We review CT and MRI evaluation of intracranial hemorrhage with the goal of providing a broad overview of the diverse causes and varied appearances of intracranial hemorrhage.
View details for DOI 10.5853/jos.2016.00563
View details for PubMedID 28030895
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Percutaneous use of a dual lumen Scepter XC balloon for embolization of a complex facial arteriovenous malformation: a technical report
CLINICAL NEURORADIOLOGY
2016; 26 (4): 485-491
View details for DOI 10.1007/s00062-016-0515-2
View details for PubMedID 27142059
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Detection and characterization of intracranial aneurysms: a 10-year multidetector CT angiography experience in a large center
JOURNAL OF NEUROINTERVENTIONAL SURGERY
2016; 8 (11): 1168-1172
Abstract
CT angiography (CTA) is increasingly used for the detection, characterization, and follow-up of intracranial aneurysms. A lower threshold to request a CT angiogram may render a patient population that differs from previous studies primarily evaluated with conventional angiography. Our objective was to broaden our knowledge of the factors associated with aneurysm rupture and patient mortality in this population.All CTA studies performed over a 10-year period at a large neurovascular referral center were reviewed for the presence of an intracranial aneurysm. Patient demographics, mortality, CTA indication, aneurysm location, size, and rupture status were recorded.2927 patients with aneurysms were identified among 29 003 CTAs. 17% of the aneurysms were ruptured at the time of imaging, 24% of aneurysms were incidentally identified, and multiple aneurysms were identified in 34% of patients. Aneurysms most commonly arose from the supraclinoid internal carotid artery (22%), the middle cerebral artery (18%), and the anterior communicating artery (13%). Male sex, age <50 years, aneurysms >6 mm, and aneurysms arising from the anterior communicating artery, posterior communicating artery, or the posterior circulation were independent predictors of aneurysm rupture. Independent mortality predictors included male sex, posterior circulation aneurysms, intraventricular hemorrhage, and intraparenchymal hemorrhage.These results indicate that aneurysms detected on CTA that arise from the anterior communicating artery, posterior communicating artery, or the posterior circulation, measure >6 mm in size, occur in men, and in patients aged <50 years are associated with rupture.
View details for DOI 10.1136/neurintsurg-2015-012082
View details for Web of Science ID 000386746200016
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Headway Duo microcatheter for cerebral arteriovenous malformation embolization with n-BCA.
Journal of neurointerventional surgery
2016; 8 (11): 1181-1185
Abstract
Cerebral arteriovenous malformations (AVMs) are uncommon vascular lesions, and hemorrhage secondary to AVM rupture results in significant morbidity and mortality. AVMs may be treated by endovascular embolization, and technical advances in microcatheter design are likely to improve the success and safety of endovascular embolization of cerebral AVMs.To describe our early experience with the Headway Duo microcatheter for embolization of cerebral AVMs with n-butyl-cyanoacrylate (n-BCA).Consecutive patients treated by endovascular embolization of a cerebral AVM with n-BCA delivered intra-arterially through the Headway Duo microcatheter (167 cm length) were identified. Patient demographic information, procedural details, and patient outcome were determined from electronic medical records.Ten consecutive patients undergoing cerebral AVM embolization using n-BCA injected through the Headway Duo microcatheter were identified. Presenting symptoms included headache, hemorrhage, seizures, and weakness. Spetzler Martin grades ranged from 1 to 5, and AVMs were located in the basal ganglia (2 patients), parietal lobe (4 patients), frontal lobe (1 patient), temporal lobe (1 patient), an entire hemisphere (1 patient), and posterior fossa (1 patient). 50 arterial pedicles were embolized, and all procedures were technically successful. There was one post-procedural hemorrhage that was well tolerated by the patient, and no other complications occurred. Additional AVM treatment was performed by surgery and radiation therapy.The Headway Duo microcatheter is safe and effective for embolization of cerebral AVMs using n-BCA. The trackability and high burst pressure of the Headway Duo make it an important and useful tool for the neurointerventionalist during cerebral AVM embolization.
View details for DOI 10.1136/neurintsurg-2015-012094
View details for PubMedID 26603031
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Detection and characterization of intracranial aneurysms: a 10-year multidetector CT angiography experience in a large center.
Journal of neurointerventional surgery
2016; 8 (11): 1168-1172
Abstract
CT angiography (CTA) is increasingly used for the detection, characterization, and follow-up of intracranial aneurysms. A lower threshold to request a CT angiogram may render a patient population that differs from previous studies primarily evaluated with conventional angiography. Our objective was to broaden our knowledge of the factors associated with aneurysm rupture and patient mortality in this population.All CTA studies performed over a 10-year period at a large neurovascular referral center were reviewed for the presence of an intracranial aneurysm. Patient demographics, mortality, CTA indication, aneurysm location, size, and rupture status were recorded.2927 patients with aneurysms were identified among 29 003 CTAs. 17% of the aneurysms were ruptured at the time of imaging, 24% of aneurysms were incidentally identified, and multiple aneurysms were identified in 34% of patients. Aneurysms most commonly arose from the supraclinoid internal carotid artery (22%), the middle cerebral artery (18%), and the anterior communicating artery (13%). Male sex, age <50 years, aneurysms >6 mm, and aneurysms arising from the anterior communicating artery, posterior communicating artery, or the posterior circulation were independent predictors of aneurysm rupture. Independent mortality predictors included male sex, posterior circulation aneurysms, intraventricular hemorrhage, and intraparenchymal hemorrhage.These results indicate that aneurysms detected on CTA that arise from the anterior communicating artery, posterior communicating artery, or the posterior circulation, measure >6 mm in size, occur in men, and in patients aged <50 years are associated with rupture.
View details for DOI 10.1136/neurintsurg-2015-012082
View details for PubMedID 26553878
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Initial experience with SOFIA as an intermediate catheter in mechanical thrombectomy for acute ischemic stroke.
Journal of neurointerventional surgery
2016
Abstract
The benefits of mechanical thrombectomy for emergent large vessel occlusion (ELVO) have been established. Combined mechanical/aspiration (Solumbra) and a direct aspiration as a first pass technique (ADAPT) are valid procedures requiring an intermediate catheter for clot suction. Recently, SOFIA (Soft torqueable catheter Optimized For Intracranial Access) was developed as a single lumen flexible catheter with coil and braid reinforcement, but its suitability for mechanical thrombectomy had not been evaluated.To describe our initial experience with SOFIA in acute stroke intervention and evaluate its efficacy and safety.All patients with ELVO undergoing endovascular stroke intervention with SOFIA were identified. Demographic, presentation, treatment, and complication data were recorded. Primary outcome was Thrombolysis in Cerebral Infarction (TICI) 2b/3 revascularization rate and the number of passes required. Secondary outcomes included complication rates and discharge National Institute of Health Stroke Scale (NIHSS) score.33 patients with a mean age of 72 years were treated for ELVO with SOFIA and IV tissue plasminogen activator was administered in 67%. Vessel occlusion involved the internal carotid artery (15.2%), M1 (48.5%), and M2 (24.2%) segments, and posterior circulation (12.1%). Median presentation NIHSS score was 14 (IQR 11-19) and discharge NIHSS 4 (IQR 2-14). The Solumbra technique represented 94% of treatments and ADAPT 3%. The TICI 2b/3 revascularization rate was 94%, including 48.5% TICI 3 with an average of 1.6 passes. The symptomatic reperfusion hemorrhage rate was 6%. Procedural complications occurred in four patients, but were unrelated to SOFIA. Mortality was 21%, secondary to failed revascularization, hemorrhagic transformation, and baseline medical condition.Mechanical and aspiration thrombectomy with SOFIA is safe and effective with high revascularization rates. Its trackability, stability, and luminal size make SOFIA suitable for stroke intervention.
View details for DOI 10.1136/neurintsurg-2016-012750
View details for PubMedID 27789787
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Cerebral vascular findings in PAPA syndrome: cerebral arterial vasculopathy or vasculitis and a posterior cerebral artery dissecting aneurysm.
Journal of neurointerventional surgery
2016; 8 (8)
Abstract
A young patient with PAPA (pyogenic arthritis, pyoderma gangrenosum, and acne) syndrome developed an unusual cerebral arterial vasculopathy/vasculitis (CAV) that resulted in subarachnoid hemorrhage from a ruptured dissecting posterior cerebral artery (PCA) aneurysm. This aneurysm was successfully treated by endovascular coil sacrifice of the affected segment of the PCA. The patient made an excellent recovery with no significant residual neurologic deficit.
View details for DOI 10.1136/neurintsurg-2015-011753.rep
View details for PubMedID 26122324
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Detection of Cortical Venous Drainage and Determination of the Borden Type of Dural Arteriovenous Fistula by Means of 3D Pseudocontinuous Arterial Spin-Labeling MRI
AMERICAN JOURNAL OF ROENTGENOLOGY
2016; 207 (1): 163-169
Abstract
The risk of intracranial dural arteriovenous fistula is linked to its pattern of venous drainage (Borden type), in particular the presence of cortical venous drainage. The purpose of this study was to assetss the accuracy of 3D pseudocontinuous arterial spin-labeling (ASL) MRI for noninvasive delineation of venous drainage.This retrospective study included 34 patients with a dural arteriovenous fistula who had undergone both digital subtraction angiography (DSA) and 3D pseudocontinuous ASL MRI. Two neuroradiologists blinded to the DSA results independently assessed ASL images for the presence of cortical vein hyperintensity (cortical venous drainage) and the distribution of venous hyperintensity (Borden type). DSA was used as the reference standard. The sensitivity and specificity of 3D pseudocontinuous ASL MRI for the detection of cortical venous drainage were determined. Intermodality and interobserver agreement for Borden type was determined by use of the weighted kappa statistic.Three-dimensional pseudocontinuous ASL MRI had high sensitivity (91%) and specificity (96%) for the detection of cortical venous drainage. Borden type was correctly identified with very good intermodality (weighted κ = 0.82) and interobserver (weighted κ = 0.85) agreement in 88% of patients.Three-dimensional pseudocontinuous ASL MRI is highly accurate for the detection of cortical venous drainage and determination of Borden type. With this technique, high-risk fistulas requiring treatment can be reliably differentiated from low-risk lesions. Although it cannot replace DSA, incorporating 3D pseudocontinuous ASL into an MRI protocol for assessment of dural arteriovenous fistula can facilitate treatment planning.
View details for DOI 10.2214/AJR.15.15171
View details for PubMedID 27082987
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Reply.
AJNR. American journal of neuroradiology
2016; 37 (6): E54-?
View details for DOI 10.3174/ajnr.A4802
View details for PubMedID 27056429
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Acute Stroke Imaging Research Roadmap III Imaging Selection and Outcomes in Acute Stroke Reperfusion Clinical Trials Consensus Recommendations and Further Research Priorities
STROKE
2016; 47 (5): 1389-1398
Abstract
The Stroke Imaging Research (STIR) group, the Imaging Working Group of StrokeNet, the American Society of Neuroradiology, and the Foundation of the American Society of Neuroradiology sponsored an imaging session and workshop during the Stroke Treatment Academy Industry Roundtable (STAIR) IX on October 5 to 6, 2015 in Washington, DC. The purpose of this roadmap was to focus on the role of imaging in future research and clinical trials.This forum brought together stroke neurologists, neuroradiologists, neuroimaging research scientists, members of the National Institute of Neurological Disorders and Stroke (NINDS), industry representatives, and members of the US Food and Drug Administration to discuss STIR priorities in the light of an unprecedented series of positive acute stroke endovascular therapy clinical trials.The imaging session summarized and compared the imaging components of the recent positive endovascular trials and proposed opportunities for pooled analyses. The imaging workshop developed consensus recommendations for optimal imaging methods for the acquisition and analysis of core, mismatch, and collaterals across multiple modalities, and also a standardized approach for measuring the final infarct volume in prospective clinical trials.Recent positive acute stroke endovascular clinical trials have demonstrated the added value of neurovascular imaging. The optimal imaging profile for endovascular treatment includes large vessel occlusion, smaller core, good collaterals, and large penumbra. However, equivalent definitions for the imaging profile parameters across modalities are needed, and a standardization effort is warranted, potentially leveraging the pooled data resulting from the recent positive endovascular trials.
View details for DOI 10.1161/STROKEAHA.115.012364
View details for PubMedID 27073243
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Perfusion Computed Tomography for the Evaluation of Acute Ischemic Stroke Strengths and Pitfalls
STROKE
2016; 47 (4): 1153-1158
View details for DOI 10.1161/STROKEAHA.116.011873
View details for Web of Science ID 000372853200040
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Perfusion Computed Tomography for the Evaluation of Acute Ischemic Stroke: Strengths and Pitfalls.
Stroke; a journal of cerebral circulation
2016
View details for DOI 10.1161/STROKEAHA.116.011873
View details for PubMedID 26965849
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Cerebral Angiography for Evaluation of Patients with CT Angiogram-Negative Subarachnoid Hemorrhage: An 11-Year Experience.
AJNR. American journal of neuroradiology
2016; 37 (2): 297-304
Abstract
CT angiography is increasingly used to evaluate patients with nontraumatic subarachnoid hemorrhage given its high sensitivity for aneurysms. We investigated the yield of digital subtraction angiography among patients with SAH or intraventricular hemorrhage and a negative CTA.An 11-year, single-center retrospective review of all consecutive patients with CTA-negative SAH was performed. Noncontrast head CT, CTA, DSA, and MR imaging studies were reviewed by 2 experienced interventional neuroradiologists and 1 neuroradiologist.Two hundred thirty patients (mean age, 54 years; 51% male) with CTA-negative SAH were identified. The pattern of SAH was diffuse (40%), perimesencephalic (31%), sulcal (31%), isolated IVH (6%), or identified by xanthochromia (7%). Initial DSA yield was 13%, including vasculitis/vasculopathy (7%), aneurysm (5%), arteriovenous malformation (0.5%), and dural arteriovenous fistula (0.5%). An additional 6 aneurysms/pseudoaneurysms (4%) were identified by follow-up DSA, and a single cavernous malformation (0.4%) was identified by MRI. No cause of hemorrhage was identified in any patient presenting with isolated intraventricular hemorrhage or xanthochromia. Diffuse SAH was due to aneurysm rupture (17%); perimesencephalic SAH was due to aneurysm rupture (3%) or vasculitis/vasculopathy (1.5%); and sulcal SAH was due to vasculitis/vasculopathy (32%), arteriovenous malformation (3%), or dural arteriovenous fistula (3%).DSA identifies vascular pathology in 13% of patients with CTA-negative SAH. Aneurysms or pseudoaneurysms are identified in an additional 4% of patients by repeat DSA following an initially negative DSA. All patients with CT-negative SAH should be considered for DSA. The pattern of SAH may suggest the cause of hemorrhage, and aneurysms should specifically be sought with diffuse or perimesencephalic SAH.
View details for DOI 10.3174/ajnr.A4503
View details for PubMedID 26338924
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Cerebral Angiography for Evaluation of Patients with CT Angiogram-Negative Subarachnoid Hemorrhage: An 11-Year Experience
AMERICAN JOURNAL OF NEURORADIOLOGY
2016; 37 (2): 297-304
Abstract
CT angiography is increasingly used to evaluate patients with nontraumatic subarachnoid hemorrhage given its high sensitivity for aneurysms. We investigated the yield of digital subtraction angiography among patients with SAH or intraventricular hemorrhage and a negative CTA.An 11-year, single-center retrospective review of all consecutive patients with CTA-negative SAH was performed. Noncontrast head CT, CTA, DSA, and MR imaging studies were reviewed by 2 experienced interventional neuroradiologists and 1 neuroradiologist.Two hundred thirty patients (mean age, 54 years; 51% male) with CTA-negative SAH were identified. The pattern of SAH was diffuse (40%), perimesencephalic (31%), sulcal (31%), isolated IVH (6%), or identified by xanthochromia (7%). Initial DSA yield was 13%, including vasculitis/vasculopathy (7%), aneurysm (5%), arteriovenous malformation (0.5%), and dural arteriovenous fistula (0.5%). An additional 6 aneurysms/pseudoaneurysms (4%) were identified by follow-up DSA, and a single cavernous malformation (0.4%) was identified by MRI. No cause of hemorrhage was identified in any patient presenting with isolated intraventricular hemorrhage or xanthochromia. Diffuse SAH was due to aneurysm rupture (17%); perimesencephalic SAH was due to aneurysm rupture (3%) or vasculitis/vasculopathy (1.5%); and sulcal SAH was due to vasculitis/vasculopathy (32%), arteriovenous malformation (3%), or dural arteriovenous fistula (3%).DSA identifies vascular pathology in 13% of patients with CTA-negative SAH. Aneurysms or pseudoaneurysms are identified in an additional 4% of patients by repeat DSA following an initially negative DSA. All patients with CT-negative SAH should be considered for DSA. The pattern of SAH may suggest the cause of hemorrhage, and aneurysms should specifically be sought with diffuse or perimesencephalic SAH.
View details for DOI 10.3174/ajnr.A4503
View details for Web of Science ID 000369111200025
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Guidelines and parameters: percutaneous sclerotherapy for the treatment of head and neck venous and lymphatic malformations.
Journal of neurointerventional surgery
2016
View details for DOI 10.1136/neurintsurg-2015-012255
View details for PubMedID 26801946
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Development of arteriovenous fistula after revascularization bypass for Moyamoya disease: case report.
Neurosurgery
2015; 11: E202-6
Abstract
Moyamoya disease is a rare cerebrovascular disorder often treated by direct and indirect revascularization bypass techniques given a typically devastating disease course and poor response to medical therapy. In this report, we describe the formation and subsequent management of a de novo arteriovenous fistula identified in the setting of a patient treated with direct bypass surgery, a previously unreported phenomenon.A 51-year-old female presenting with Suzuki stage IV bilateral moyamoya disease underwent bilateral extracranial to intracranial (EC-IC) STA-MCA bypass without complication at our institution. At six-month follow-up, she demonstrated no evidence of residual neurologic deficits or continued symptoms despite documentation of an arteriovenous fistula arising at the site of the right EC-IC bypass upon routine follow-up cerebral angiography.We present the first reported case of de novo arteriovenous fistula formation following superficial temporal artery (STA) to middle cerebral artery (MCA) bypass for the treatment of moyamoya disease. Treatment of such iatrogenic arteriovenous fistulae fed by a patent bypass vessel may prove challenging without associated compromise of the bypass, meriting careful evaluation of all potential therapeutic options. The fistula herein most likely occurred secondary to recanalization of a previously thrombosed vein of Trolard. This case demonstrates the possibility of arteriovenous fistula formation as a potential sequela of revascularization bypass surgery and lends support to the previously described traumatic etiology of fistula formation.
View details for DOI 10.1227/NEU.0000000000000558
View details for PubMedID 25251198
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Development of Arteriovenous Fistula After Revascularization Bypass for Moyamoya Disease: Case Report
OPERATIVE NEUROSURGERY
2015; 11 (1): E202-E206
View details for DOI 10.1227/NEU.0000000000000558
View details for Web of Science ID 000364210300001
View details for PubMedID 25251198
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Imaging selection for reperfusion therapy in acute ischemic stroke.
Current treatment options in neurology
2015; 17 (2): 332-?
Abstract
Neuroimaging is essential in the evaluation of the acute stroke patient. Computed tomography (CT) or magnetic resonance imaging (MRI) should be used to confirm the diagnosis of acute stroke, exclude stroke mimics, and triage patients for intravenous tissue plasminogen activator and endovascular revascularization therapies. Advanced neuroimaging techniques, including CT-angiography, MR-angiography, CT-perfusion, and MR-perfusion should be used to further inform acute stroke treatment decisions. Patients considered for endovascular stroke therapy should have (1) a vascular occlusion that can be reached by an endovascular approach; (2) a small area of core cerebral infarction; and (3) viable tissue at risk of infarction if prompt revascularization is not achieved (penumbra).
View details for DOI 10.1007/s11940-014-0332-3
View details for PubMedID 25619536
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Imaging selection for reperfusion therapy in acute ischemic stroke.
Current treatment options in neurology
2015; 17 (2): 332-?
View details for DOI 10.1007/s11940-014-0332-3
View details for PubMedID 25619536
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Persistent trigeminal artery supply to an intrinsic trigeminal nerve arteriovenous malformation: A rare cause of trigeminal neuralgia.
Journal of clinical neuroscience
2015; 22 (2): 409-412
Abstract
Infratentorial arteriovenous malformations (AVM) associated with the trigeminal nerve root entry zone are a known cause of secondary trigeminal neuralgia (TN). The treatment of both TN and AVM can be challenging, especially if the AVM is embedded within the trigeminal nerve. A persistent trigeminal artery (PTA) can rarely supply these intrinsic trigeminal nerve AVM. We present a 64-year-old man with TN from a right trigeminal nerve AVM supplied by a PTA variant. The patient underwent microvascular decompression and a partial resection of the AVM with relief of facial pain symptoms. His residual AVM was subsequently treated with CyberKnife radiosurgery (Accuray, Sunnyvale, CA, USA). A multimodality approach may be required for the treatment of trigeminal nerve associated PTA AVM and important anatomic patterns need to be recognized before any treatment. Herein, we report to our knowledge the third documented patient with a posterior fossa AVM supplied by a PTA and the first PTA AVM presenting as facial pain.
View details for DOI 10.1016/j.jocn.2014.06.007
View details for PubMedID 25070632
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Cerebral vascular findings in PAPA syndrome: cerebral arterial vasculopathy or vasculitis and a posterior cerebral artery dissecting aneurysm.
BMJ case reports
2015; 2015
Abstract
A young patient with PAPA (pyogenic arthritis, pyoderma gangrenosum, and acne) syndrome developed an unusual cerebral arterial vasculopathy/vasculitis (CAV) that resulted in subarachnoid hemorrhage from a ruptured dissecting posterior cerebral artery (PCA) aneurysm. This aneurysm was successfully treated by endovascular coil sacrifice of the affected segment of the PCA. The patient made an excellent recovery with no significant residual neurologic deficit.
View details for DOI 10.1136/bcr-2015-011753
View details for PubMedID 26109622
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Cerebral angioplasty using the Scepter XC dual lumen balloon for the treatment of vasospasm following intracranial aneurysm rupture
JOURNAL OF NEUROINTERVENTIONAL SURGERY
2015; 7 (1): 56-61
Abstract
Cerebral vasospasm following subarachnoid hemorrhage (SAH) results in significant morbidity and mortality. Intra-arterial administration of calcium channel blockers or intracranial angioplasty may be performed when non-invasive medical management fails to prevent neurologic deterioration. Technical improvements in balloon catheters are expected to improve the success and safety of cerebral angioplasty.To describe our initial experience with the new Scepter XC balloon catheter in cerebral vasospasm treatment following SAH.All patients who underwent cerebral angioplasty using the Scepter XC balloon for the treatment of medically refractory cerebral vasospasm after SAH were identified. Patient demographic information, procedural details, and outcome were obtained from electronic medical records.Five consecutive patients undergoing vasospasm treatment with cerebral angioplasty using the Scepter XC were identified. All treated patients had medically refractory vasospasm that was moderate or severe. Angioplasty of the supraclinoid internal carotid artery, the A1 and A2 segments of the anterior cerebral artery, the M1 and M2 segments of the middle cerebral artery, the V4 segment of the vertebral artery, and the basilar artery was performed. All angioplasty procedures were technically successful, and the degree of vasospasm improved significantly following angioplasty. There were no complications related to the cerebral angioplasty procedures.The Scepter XC balloon catheter is safe and effective in the treatment of cerebral vasospasm following SAH. The excellent trackability and stability of the balloon catheter and the extra compliant design of the balloon represent technical advancements in the endovascular armamentarium in the treatment of cerebral vasospasm.
View details for DOI 10.1136/neurintsurg-2013-011043
View details for PubMedID 24385556
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Unruptured intracranial aneurysms conservatively followed with serial CT angiography: could morphology and growth predict rupture?
JOURNAL OF NEUROINTERVENTIONAL SURGERY
2014; 6 (10): 761-766
Abstract
Despite several landmark studies, the natural history of unruptured intracranial aneurysms (UIA) remains uncertain. Our aim was to identify or confirm factors predictive of rupture of UIA being observed conservatively with serial CT angiography (CTA) in a North American patient population.We performed a retrospective review of patients with UIA being followed with serial CTA studies from 1999 to 2010. The following features for each aneurysm were cataloged from the official radiologic reports and CTA images: maximum diameter, growth between follow-up studies, location, multiplicity, wall calcification, intraluminal thrombus and morphology. Univariate logistic regression analysis of the potential independent risk factors for aneurysm rupture was performed. Statistically significant risk factors from the univariate analysis were then entered into a multivariate logistic regression analysis.152 patients with a total of 180 UIA had at least two CTA studies. Six aneurysms in six different patients ruptured during the CTA follow-up period for an overall rupture rate of 3.3% and an annual rupture rate of 0.97%. All ruptured aneurysms were ≥9 mm. In the univariate analysis, the statistically significant predictors of aneurysm rupture were aneurysm size (p=0.003), aneurysm growth (p<0.0001) and aneurysm multilobulation (p=0.001). The risk factors that remained significant following the multivariate analysis were growth (OR 55.9; 95% CI 4.47 to 700.08; p=0.002) and multilobulation (OR 17.4; 95% CI 1.52 to 198.4; p=0.022).Aneurysm morphology and interval growth are characteristics predictive of a higher risk of subsequent rupture during conservative CTA follow-up.
View details for DOI 10.1136/neurintsurg-2013-010944
View details for Web of Science ID 000344939800014
View details for PubMedID 24275611
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Endovascular reconstruction of enlarging traumatic internal carotid artery pseudoaneurysm.
Neurosurgical focus
2014; 37 (1): 1-?
Abstract
Traumatic dissecting pseudoaneurysms of the cervical and petrous internal carotid artery are often a result of blunt or penetrating trauma. These patients are at high risk for thromboembolic complications and are managed with antiplatelet agents. Patients who develop neurologic symptoms while on antiplatelet agents, or have interval enlargement of their pseudoaneurysms, may require repair of the vessel. We describe a case in which we performed an endovascular repair of an enlarging distal cervical internal carotid artery pseudoaneurysm, with placement of a covered stent. The video can be found here: http://youtu.be/uCypcsBvOZ4 .
View details for DOI 10.3171/2014.V2.FOCUS14185
View details for PubMedID 24983722
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E-013 endovascular management of pseudoaneurysms secondary to external ventricular drain placement: single center experience.
Journal of neurointerventional surgery
2014; 6: A43-4
Abstract
Placement of external ventricular drains is a common, life-saving neurosurgical procedure indicated across a variety of settings. While advances have made the procedure quite safe, the potential for iatrogenic morbidity and mortality continues. Herein, we document our experience with the endovascular management of three pseudoaneurysms associated with EVD placement.We performed a retrospective analysis to identify all EVDs placed from 2008 through 2013 at our institution,. In instances of EVD-associated cerebrovascular injury, all admission and subsequent radiographic studies were reviewed, including cerebral angiograms and computed tomography (CT) scans. Angiograms were reviewed to record the extent of vascular injury and angiographic outcomes after treatment.One female and two male patients (40-75 years) were found to have developed vascular injuries associated with EVD placement. Three pseudoaneurysms, namely of the posterior communicating artery (PCOM), pericallosal artery branch and the middle meningeal artery, were treated by coil and/or glue embolization.Although EVD-associated cerebrovascular injury remains a rare phenomenon, such procedures are not entirely benign. Endovascular repair for such lesions proves a viable, effective option.arteriovenous fistula (AVF), computed tomography (CT), external ventricular drain (EVD), posterior communicating artery (PCOM), posterior cerebral artery (PCA) DISCLOSURES: O. Choudhri: None. M. Gupta: None. J. Heit: None. A. Feroze: None. H. Do: None.
View details for DOI 10.1136/neurintsurg-2014-011343.80
View details for PubMedID 25064928
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Endovascular management of external ventricular drain-associated cerebrovascular injuries.
Surgical neurology international
2014; 5: 167-?
Abstract
Placement of external ventricular drains (EVDs) is a common, life-saving neurosurgical procedure indicated across a variety of settings. While advances have made the procedure quite safe, the potential for iatrogenic morbidity and mortality continues. We document our experience with the endovascular management of three pseudoaneurysms associated with EVD placement and discuss the endovascular treatment options for EVD-associated cerebrovascular injury.We performed a retrospective analysis to identify all EVDs placed from 2008 through 2013 at our institution. In instances of EVD-associated cerebrovascular injury, all admission and subsequent radiographic studies were reviewed, including cerebral angiograms and computed tomography (CT) scans where available. Angiograms were reviewed to record the extent of vascular injury and outcomes after treatment.One female and two male patients (age range, 40-75 years) were found to have developed vascular injuries associated with EVD placement. Three pseudoaneurysms, of the posterior communicating artery (PCOM), pericallosal artery branch, and the middle meningeal artery, respectively, were treated by coil and/or glue embolization.Although EVD-associated cerebrovascular injury remains a rare phenomenon, such procedures are not entirely benign. Endovascular repair for such lesions proves a viable, effective option.
View details for DOI 10.4103/2152-7806.145930
View details for PubMedID 25558425
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Prospective Validation of the Computed Tomographic Angiography Spot Sign Score for Intracerebral Hemorrhage
STROKE
2013; 44 (11): 3097-3102
Abstract
Intracerebral hemorrhage (ICH) results in high mortality and morbidity for patients. Previous retrospective studies correlated the spot sign score (SSSc) with ICH expansion, mortality, and clinical outcome among ICH survivors. We performed a prospective study to validate the SSSc for the prediction of ICH expansion, mortality, and clinical outcome among survivors.We prospectively included consecutive patients with primary ICH presenting to a single institution for a 1.5-year period. All patients underwent baseline noncontrast computed tomography (CT) and multidetector CT angiography performed within 24 hours of admission and a follow-up noncontrast CT within 48 hours after the initial CT. The ICH volume was calculated on the noncontrast CT images using semiautomated software. The SSSc was calculated on the multidetector CT angiographic source images. We assessed in-hospital mortality and modified Rankin Scale at discharge and at 3 months among survivors. A multivariate logistic regression analysis was performed to determine independent predictors of hematoma expansion, in-hospital mortality, and poor clinical outcome.A total of 131 patients met the inclusion criteria. Of the 131 patients, a spot sign was detected in 31 patients (24%). In a multivariate analysis, the SSSc predicted significant hematoma expansion (odds ratio, 3.1; 95% confidence interval, 1.77-5.39; P≤0.0001), in-hospital mortality (odds ratio, 4.1; 95% confidence interval, 2.11-7.94; P≤0.0001), and poor clinical outcome (odds ratio, 3; 95% confidence interval, 1.4-4.42; P=0.004). In addition, the SSSc was an accurate grading scale for ICH expansion, modified Rankin Scale at discharge, and in-hospital mortality.The SSSc demonstrated a strong stepwise correlation with hematoma expansion and clinical outcome in patients with primary ICH.
View details for DOI 10.1161/STROKEAHA.113.002752
View details for Web of Science ID 000325987300038
View details for PubMedID 24021687
View details for PubMedCentralID PMC4187102
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Impact of online education on intern behaviour around joint commission national patient safety goals: a randomised trial
BMJ QUALITY & SAFETY
2012; 21 (10): 819-825
Abstract
To compare the effectiveness of two types of online learning methodologies for improving the patient-safety behaviours mandated in the Joint Commission National Patient Safety Goals (NPSG).This randomised controlled trial was conducted in 2010 at Massachusetts General Hospital and Brigham and Women's Hospital (BWH) in Boston USA. Incoming interns were randomised to either receive an online Spaced Education (SE) programme consisting of cases and questions that reinforce over time, or a programme consisting of an online slide show followed by a quiz (SQ). The outcome measures included NPSG-knowledge improvement, NPSG-compliant behaviours in a simulation scenario, self-reported confidence in safety and quality, programme acceptability and programme relevance.Both online learning programmes improved knowledge retention. On four out of seven survey items measuring satisfaction and self-reported confidence, the proportion of SE interns responding positively was significantly higher (p<0.05) than the fraction of SQ interns. SE interns demonstrated a mean 4.79 (36.6%) NPSG-compliant behaviours (out of 13 total), while SQ interns completed a mean 4.17 (32.0%) (p=0.09). Among those in surgical fields, SE interns demonstrated a mean 5.67 (43.6%) NPSG-compliant behaviours, while SQ interns completed a mean 2.33 (17.9%) (p=0.015). Focus group data indicates that SE was more contextually relevant than SQ, and significantly more engaging.While both online methodologies improved knowledge surrounding the NPSG, SE was more contextually relevant to trainees and was engaging. SE impacted more significantly on both self-reported confidence and the behaviour of surgical residents in a simulated scenario.
View details for DOI 10.1136/bmjqs-2011-000702
View details for Web of Science ID 000309513900003
View details for PubMedID 22706930
View details for PubMedCentralID PMC4068823
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Spot sign score predicts rapid bleeding in spontaneous intracerebral hemorrhage.
Emergency radiology
2012; 19 (3): 195-202
Abstract
This study was conducted to determine whether spot sign score correlates with average rate of hematoma expansion and whether average rate of expansion predicts in-hospital mortality and clinical outcome in spontaneous intracerebral hemorrhage (ICH). The study included 367 patients presenting to the Emergency Department (ED) from January 1, 2000 to December 31, 2008 with nontraumatic ICH. All received noncontrast computed tomography (NCCT) of the head and multidetector CT angiography (MDCTA) on presentation to the ED and a follow-up NCCT within 48 h. Imaging was used to determine the hematoma location and volume, average rate of expansion, and spot sign score. Primary outcome measures included in-hospital mortality and clinical outcome based on modified Rankin Scale at 3 months or at discharge. Regression analysis was performed to correlate spot sign score and average rate of hematoma expansion. ICH expansion was identified in 194 of 367 patients (53%). In a multivariate analysis, rate of ICH expansion predicted mortality (hazard ratio 1.1, CI 1.08-1.12, p < 0.0001). Patients who expired had an average rate of ICH expansion of 2.8 ml/h compared to 0.2 ml/h in survivors. Spot sign score on presentation to the ED correlated with the average rate of hematoma expansion. Average rate of hematoma expansion predicts mortality in spontaneous ICH. Spot sign score on presentation correlates with rate of expansion, supporting the hypothesis that high spot sign scores likely reflect active bleeding in acute ICH.
View details for DOI 10.1007/s10140-012-1020-9
View details for PubMedID 22271362
View details for PubMedCentralID PMC4318560
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Safety and Efficacy of Percutaneous Fiducial Marker Implantation for Image-guided Radiation Therapy
JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY
2009; 20 (2): 235-239
Abstract
To evaluate the safety and technical success rate of percutaneous fiducial marker implantation in preparation for image-guided radiation therapy.From January 2003 to January 2008, we retrospectively reviewed 139 percutaneous fiducial marker implantations in 132 patients. Of the 139 implantations, 44 were in the lung, 61 were in the pancreas, and 34 were in the liver. Procedure-related major and minor complications were documented. Technical success was defined as implantation enabling adequate treatment planning and computed tomographic simulation.The major and minor complication rates were 5% and 17.3%, respectively. Pneumothorax after lung implantation was the most common complication. Pneumothoraces were seen in 20 of the 44 lung implantations (45%); a chest tube was required in only seven of the 44 lung transplantations (16%). Of the 139 implantations, 133 were successful; in six implantations (4.3%) the fiducial markers migrated and required additional procedures or alternate methods of implantation.Percutaneous implantation of fiducial marker is a safe and effective procedure with risks that are similar to those of conventional percutaneous organ biopsy.
View details for DOI 10.1016/j.jvir.2008.09.026
View details for PubMedID 19019700
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Menin controls growth of pancreatic beta-cells in pregnant mice and promotes gestational diabetes mellitus
SCIENCE
2007; 318 (5851): 806-809
Abstract
During pregnancy, maternal pancreatic islets grow to match dynamic physiological demands, but the mechanisms regulating adaptive islet growth in this setting are poorly understood. Here we show that menin, a protein previously characterized as an endocrine tumor suppressor and transcriptional regulator, controls islet growth in pregnant mice. Pregnancy stimulated proliferation of maternal pancreatic islet beta-cells that was accompanied by reduced islet levels of menin and its targets. Transgenic expression of menin in maternal beta-cells prevented islet expansion and led to hyperglycemia and impaired glucose tolerance, hallmark features of gestational diabetes. Prolactin, a hormonal regulator of pregnancy, repressed islet menin levels and stimulated beta-cell proliferation. These results expand our understanding of mechanisms underlying diabetes pathogenesis and reveal potential targets for therapy in diabetes.
View details for DOI 10.1126/science.1146812
View details for PubMedID 17975067
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Calcineurin/NFAT signaling in the beta-cell: from diabetes to new therapeutics
BIOESSAYS
2007; 29 (10): 1011-1021
Abstract
Pancreatic beta-cells in the islet of Langerhans produce the hormone insulin, which maintains blood glucose homeostasis. Perturbations in beta-cell function may lead to impairment of insulin production and secretion and the onset of diabetes mellitus. Several essential beta-cell factors have been identified that are required for normal beta-cell function, including six genes that when mutated give rise to inherited forms of diabetes known as Maturity Onset Diabetes of the Young (MODY). However, the intracellular signaling pathways that control expression of MODY and other factors continue to be revealed. Post-transplant diabetes mellitus in patients taking the calcineurin inhibitors tacrolimus (FK506) or cyclosporin A indicates that calcineurin and its substrate the Nuclear Factor of Activated T-cells (NFAT) may be required for beta-cell function. Here recent advances in our understanding of calcineurin and NFAT signaling in the beta-cell are reviewed. Novel therapeutic approaches for the treatment of diabetes are also discussed.
View details for DOI 10.1002/bies.20644
View details for PubMedID 17876792
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Calcineurin/NFAT signalling regulates pancreatic beta-cell growth and function
NATURE
2006; 443 (7109): 345-349
Abstract
The growth and function of organs such as pancreatic islets adapt to meet physiological challenges and maintain metabolic balance, but the mechanisms controlling these facultative responses are unclear. Diabetes in patients treated with calcineurin inhibitors such as cyclosporin A indicates that calcineurin/nuclear factor of activated T-cells (NFAT) signalling might control adaptive islet responses, but the roles of this pathway in beta-cells in vivo are not understood. Here we show that mice with a beta-cell-specific deletion of the calcineurin phosphatase regulatory subunit, calcineurin b1 (Cnb1), develop age-dependent diabetes characterized by decreased beta-cell proliferation and mass, reduced pancreatic insulin content and hypoinsulinaemia. Moreover, beta-cells lacking Cnb1 have a reduced expression of established regulators of beta-cell proliferation. Conditional expression of active NFATc1 in Cnb1-deficient beta-cells rescues these defects and prevents diabetes. In normal adult beta-cells, conditional NFAT activation promotes the expression of cell-cycle regulators and increases beta-cell proliferation and mass, resulting in hyperinsulinaemia. Conditional NFAT activation also induces the expression of genes critical for beta-cell endocrine function, including all six genes mutated in hereditary forms of monogenic type 2 diabetes. Thus, calcineurin/NFAT signalling regulates multiple factors that control growth and hallmark beta-cell functions, revealing unique models for the pathogenesis and therapy of diabetes.
View details for DOI 10.1038/nature05097
View details for PubMedID 16988714
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NFAT dysregulation by increased dosage of DSCR1 and DYRK1A on chromosome 21
NATURE
2006; 441 (7093): 595-600
Abstract
Trisomy 21 results in Down's syndrome, but little is known about how a 1.5-fold increase in gene dosage produces the pleiotropic phenotypes of Down's syndrome. Here we report that two genes, DSCR1 and DYRK1A , lie within the critical region of human chromosome 21 and act synergistically to prevent nuclear occupancy of NFATc transcription factors, which are regulators of vertebrate development. We use mathematical modelling to predict that autoregulation within the pathway accentuates the effects of trisomy of DSCR1 and DYRK1A, leading to failure to activate NFATc target genes under specific conditions. Our observations of calcineurin-and Nfatc-deficient mice, Dscr1- and Dyrk1a-overexpressing mice, mouse models of Down's syndrome and human trisomy 21 are consistent with these predictions. We suggest that the 1.5-fold increase in dosage of DSCR1 and DYRK1A cooperatively destabilizes a regulatory circuit, leading to reduced NFATc activity and many of the features of Down's syndrome. More generally, these observations suggest that the destabilization of regulatory circuits can underlie human disease.
View details for DOI 10.1038/nature04678
View details for PubMedID 16554754
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Intrinsic regulators of pancreatic beta-cell proliferation
ANNUAL REVIEW OF CELL AND DEVELOPMENTAL BIOLOGY
2006; 22: 311-338
Abstract
Once thought incapable of significant proliferation, the pancreatic beta-cell has recently been shown to harbor immense powers of self-renewal. Pancreatic beta-cells, the sole source of insulin in vertebrate animals, can grow facultatively to a degree unmatched by other organs in experimental animals. beta-cell growth matches changes in systemic insulin demand, which increase during common physiologic states such as aging, obesity, and pregnancy. Compensatory changes in beta-cell mass are controlled by beta-cell proliferation. Here we review recent advances in our understanding of the intrinsic factors and mechanisms that control beta-cell cycle progression. Dysregulation of beta-cell proliferation is emerging as a fundamental feature in the pathogenesis of human disease states such as cancer and diabetes mellitus. New experimental observations and studies of these diseases suggest that beta-cell fate and expansion are coordinately regulated. We speculate on how these advances may accelerate the discovery of new strategies for the treatment of diseases characterized by a deficiency or excess of beta-cells.
View details for DOI 10.1146/annurev.cellbio.22.010305.104425
View details for PubMedID 16824015
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Embryonic stem cells and islet replacement in diabetes mellitus
PEDIATRIC DIABETES
2004; 5: 5-15
Abstract
Transplantation of functional islets of Langerhans may emerge as a useful therapy for some patients with type 1 diabetes mellitus (DM), but donor islet shortages motivate the search for new sources of transplantable islets. Pluripotent embryonic stem (ES) cells are expandable in culture and have the potential to give rise to all cell types in the body. The recent isolation of pluripotent ES cells from humans has generated excitement over the possibility of engineering glucose-responsive islet replacement tissue from these cells in large quantities. In this study, we review the recent advances in generating insulin-producing cells (IPC) from mouse and human ES (hES) cells.
View details for PubMedID 15601369
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N-terminal domain of yeast telomerase reverse transcriptase: Recruitment of Est3p to the telomerase complex
MOLECULAR BIOLOGY OF THE CELL
2003; 14 (1): 1-13
Abstract
Telomerase is a reverse transcriptase that maintains chromosome ends. The N-terminal half of the catalytic protein subunit (TERT) contains three functional domains (I, II, and III) that are conserved among TERTs but not found in other reverse transcriptases. Guided by an amino acid sequence alignment of nine TERT proteins, mutations were introduced into yeast TERT (Est2p). In support of the proposed alignment, mutation of virtually all conserved residues resulted in loss-of-function or temperature sensitivity, accompanied by telomere shortening. Overexpression of telomerase component Est3p led to allele-specific suppression of the temperature-sensitive mutations in region I, suggesting that Est3p interacts with this protein domain. As predicted by the genetic results, a lethal mutation in region I resulted in loss of Est3p from the telomerase complex. We conclude that Est2p region I is required for the recruitment of Est3p to yeast telomerase. Given the phylogenetic conservation of region I of TERT, this protein domain may provide the equivalent function in all telomerases.
View details for DOI 10.1091/mbc.E02-06-0327
View details for Web of Science ID 000180497300002
View details for PubMedID 12529422
View details for PubMedCentralID PMC140223
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Growth inhibitors promote differentiation of insulin-producing tissue from embryonic stem cells
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2002; 99 (25): 16105-16110
Abstract
The use of embryonic stem cells for cell-replacement therapy in diseases like diabetes mellitus requires methods to control the development of multipotent cells. We report that treatment of mouse embryonic stem cells with inhibitors of phosphoinositide 3-kinase, an essential intracellular signaling regulator, produced cells that resembled pancreatic beta cells in several ways. These cells aggregated in structures similar, but not identical, to pancreatic islets of Langerhans, produced insulin at levels far greater than previously reported, and displayed glucose-dependent insulin release in vitro. Transplantation of these cell aggregates increased circulating insulin levels, reduced weight loss, improved glycemic control, and completely rescued survival in mice with diabetes mellitus. Graft removal resulted in rapid relapse and death. Graft analysis revealed that transplanted insulin-producing cells remained differentiated, enlarged, and did not form detectable tumors. These results provide evidence that embryonic stem cells can serve as the source of insulin-producing replacement tissue in an experimental model of diabetes mellitus. Strategies for producing cells that can replace islet functions described here can be adapted for similar uses with human cells.
View details for DOI 10.1073/pnas.252618999
View details for PubMedID 12441403