Global Disparities in the Presentation and Management of Aneurysmal Subarachnoid Hemorrhage (aSAH): A Review and Analysis.

Aneurysmal subarachnoid hemorrhage (aSAH) is associated with high mortality rates. There is a significant gap in the literature describing global disparities in demographics, management, and outcomes among patients with aSAH. We aimed to conduct a systematic review and meta-analysis to assess global disparities in aSAH presentation and management. PubMed and Embase databases were queried from earliest records to November 2022 for aSAH literature. Presentation, demographics, comorbidities, treatment methods, and outcomes data were collected. Articles that did not report aSAH-specific patient management and outcomes were excluded. Pooled weighted prevalence rates were calculated. Random effects model rates were reported. After screening, 33 articles representing 10,553 patients were included. The prevalence of Fisher grade 3 or 4 aSAH in high- and lower-income countries (HIC and LIC), respectively, was 79.8% (P<0.01) and 84.1 (P<0.01). Prevalence of male aSAH patients in HIC and LIC, respectively, was 35.8% (P<0.01) and 45.0% (P<0.01). Prevalence of treatment in aSAH patients was 99.5% (P<0.01) and 99.4% (P=0.16) in HIC and LIC, respectively. In HIC, 35% (P<0.01) of aneurysms in aSAH patients were treated with coiling. No LIC reported coiling for aSAH treatment; LIC only reported rates of surgical clipping, with a total prevalence of 92.4% (P<0.01) vs. 65.6% (P<0.01) in HIC. In this analysis, we found similar rates of high-grade SAH hemorrhages in HIC and LIC but a lack of endovascular coil embolization treatments reported in LIC. Additional research and discussion are needed to identify reasons for treatment disparities and intervenable societal factors to improve aSAH outcomes worldwide.

Anesthesia modality in endovascular treatment for distal medium vessel occlusion stroke: intention-to-treat propensity score-matched analysis.

BACKGROUND: The optimal anesthesia modality during endovascular treatment (EVT) for distal medium vessel occlusion (DMVO) stroke is uncertain. We aimed to evaluate the association of the anesthesia modality with procedural and clinical outcomes following EVT for DMVO stroke. METHODS: This is a multicenter retrospective analysis of a prospectively collected database. Patients were included if they had DMVO involving the middle cerebral artery-M3/4, anterior cerebral artery-A2/3, or posterior cerebral artery-P1/P2-3, and underwent EVT. The cohort was divided into two groups, general anesthesia (GA) and non-general anesthesia (non-GA), and compared based on the intention-to-treat principle as primary analysis. We used propensity scores to balance the two groups. The primary outcome was the shift in the degree of disability as measured by the 90-day modified Rankin Scale (mRS). Secondary outcomes included successful reperfusion, as well as excellent (mRS 0-1) and good (mRS 0-2) clinical outcomes at 90 days. Safety measures included procedural complications, symptomatic intracerebral hemorrhage (sICH), and 90-day mortality. RESULTS: Among 366 DMVO thrombectomies, 61 matched pairs were eligible for analysis. Median age and National Institutes of Health Stroke Scale score as well as other baseline demographic and clinical characteristics were balanced between both groups. The GA group had no difference in the overall degree of disability (common OR 1.19, 95% CI 0.52 to 2.86, P=0.67) compared with the non-GA arm. Likewise, the GA group had comparable rates of successful reperfusion (OR 2.38, 95% CI 0.80 to 7.07, P=0.12), good/excellent clinical outcomes (OR 1.14, 95% CI 0.44 to 2.96, P=0.79/(OR 0.65, 95% CI 0.24 to 1.81, P=0.41), procedural complications (OR 1.00, 95% CI 0.19 to 5.16, P>0.99), sICH (OR 3.24, 95% CI 0.83 to 12.68, P=0.09), and 90-day mortality (OR 1.43, 95% CI 0.48 to 4.27, P=0.52) compared with the non-GA group. CONCLUSIONS: In patients with DMVO, our study showed that GA and non-GA groups had similar procedural and clinical outcomes, as well as safety measures. Further larger controlled studies are warranted.

Decoding Molecular Mechanisms Underlying Outcomes After Ischemic Stroke Thrombectomy by RNA Sequencing of Retrieved Clots.

BACKGROUND: Transcriptomic profiling has emerged as a powerful tool for exploring the molecular landscape of ischemic stroke clots and providing insights into the pathophysiological mechanisms underlying stroke progression and recovery. In this study, we aimed to investigate the relationship between stroke clot transcriptomes and stroke thrombectomy outcome, as measured by early neurological improvement (ENI) 30 (i.e., a 30% reduction in NIHSS at 24 h post-thrombectomy). HYPOTHESIS: We hypothesized that there exist distinct clot gene expression patterns between good and poor neurological outcomes. METHODS: Transcriptomic analysis of 32 stroke clots retrieved by mechanical thrombectomy was conducted. Transcriptome data of these clots were analyzed to identify differentially expressed genes (DEGs), defined as those with a log(fold-change) ≥ 1.5 and q < 0.05 between samples with good and poor early neurological outcomes. Gene ontology and bioinformatics analyses were performed on genes with p < 0.01 to identify enriched biological processes and Ingenuity Pathway Analysis canonical pathways. Moreover, AUC analysis assessed the predictive power of DEGs for 90-day function outcome (mRS ≤ 2) and cellular composition of clot was predicted using CIBERSORT. We also assessed whether differential enrichment of immune cell types could indicate patient survival. RESULTS: A total of 41 DEGs were identified. Bioinformatics showed that enriched biological processes and pathways emphasized the chronic immune response and matrix metalloproteinase inhibition. Moreover, 25 of the DEGs were found to be significant predictors of 90-day mRS. These genes were indicative of monocytes enrichment and neutrophil depletion in patients with poorer outcomes. CONCLUSION: Our study revealed a distinct gene expression pattern and dysregulated biological pathways associated with ENI. This expression pattern was also predictive of long-term outcome, suggesting a biological link between those ENIs and 90-day mRS.

Radiomics-Based Predictive Nomogram for Assessing the Risk of Intracranial Aneurysms.

Background: Aneurysm wall enhancement (AWE) has the potential to be used as an imaging biomarker for the risk stratification of intracranial aneurysms (IAs). Radiomics provides a refined approach to quantify and further characterize AWE's textural features. This study examines the performance of AWE quantification combined with clinical information in detecting symptomatic IAs. Methods: Ninety patients harboring 104 IAs (29 symptomatic and 75 asymptomatic) underwent high-resolution magnetic resonance imaging (HR-MRI). The assessment of AWE was performed using two different methods: 3D-AWE mapping and composite radiomics-based score (RadScore). The dataset was split into training and testing subsets. The testing set was used to build two different nomograms using each modality of AWE assessment combined with patients' demographic information and aneurysm morphological data. Finally, each nomogram was evaluated on an independent testing set. Results: A total of 22 radiomic features were significantly different between symptomatic and asymptomatic IAs. The 3D-AWE Mapping nomogram achieved an area under the curve (AUC) of 0.77 (63% accuracy, 78% sensitivity and 58% specificity). The RadScore nomogram exhibited a better performance, achieving an AUC of 0.83 (77% accuracy, 89% sensitivity and 73% specificity). Conclusions : Combining AWE quantification through radiomic analysis with patient demographic data in a clinical nomogram achieved high accuracy in detecting symptomatic IAs.

Diffusion-Weighted Imaging Fluid-Attenuated Inversion Recovery Mismatch on Portable, Low-Field Magnetic Resonance Imaging Among Acute Stroke Patients.

OBJECTIVE: For stroke patients with unknown time of onset, mismatch between diffusion-weighted imaging (DWI) and fluid-attenuated inversion recovery (FLAIR) magnetic resonance imaging (MRI) can guide thrombolytic intervention. However, access to MRI for hyperacute stroke is limited. Here, we sought to evaluate whether a portable, low-field (LF)-MRI scanner can identify DWI-FLAIR mismatch in acute ischemic stroke. METHODS: Eligible patients with a diagnosis of acute ischemic stroke underwent LF-MRI acquisition on a 0.064-T scanner within 24 h of last known well. Qualitative and quantitative metrics were evaluated. Two trained assessors determined the visibility of stroke lesions on LF-FLAIR. An image coregistration pipeline was developed, and the LF-FLAIR signal intensity ratio (SIR) was derived. RESULTS: The study included 71 patients aged 71 ± 14 years and a National Institutes of Health Stroke Scale of 6 (interquartile range 3-14). The interobserver agreement for identifying visible FLAIR hyperintensities was high (κ = 0.85, 95% CI 0.70-0.99). Visual DWI-FLAIR mismatch had a 60% sensitivity and 82% specificity for stroke patients <4.5 h, with a negative predictive value of 93%. LF-FLAIR SIR had a mean value of 1.18 ± 0.18 <4.5 h, 1.24 ± 0.39 4.5-6 h, and 1.40 ± 0.23 >6 h of stroke onset. The optimal cut-point for LF-FLAIR SIR was 1.15, with 85% sensitivity and 70% specificity. A cut-point of 6.6 h was established for a FLAIR SIR <1.15, with an 89% sensitivity and 62% specificity. INTERPRETATION: A 0.064-T portable LF-MRI can identify DWI-FLAIR mismatch among patients with acute ischemic stroke. Future research is needed to prospectively validate thresholds and evaluate a role of LF-MRI in guiding thrombolysis among stroke patients with uncertain time of onset. ANN NEUROL 2024.

Population-based estimates suggest middle meningeal artery embolization for subdural hematomas could significantly expand the scope of neurovascular therapies.

BACKGROUND: This study quantifies the impact of middle meningeal artery embolization (MMAE) for subdural hematomas (SDHs) by estimating a target population. METHODS: A population-based study at a tertiary hospital, the main SDH facility for a four-county population, used primary ICD-10 codes over 3 years to collate SDH hospitalizations. Clinical and imaging data confirmed traumatic versus non-traumatic and acute versus non-acute (mixed or chronic) SDH. The MMAE-eligible population included patients with non-traumatic, non-acute SDH aged ≥18 years plus patients with 'traumatic' but non-acute SDH aged ≥60 years presenting with a fall. This was contrasted with the rate of large vessel strokes in the same population. RESULTS: 1279 hospitalizations with a primary ICD-10 SDH diagnosis were identified, with 389 from the study population. Excluding repeat admissions, 350 patients were analyzed, 233 (67%) traumatic, and 117 (33%) non-traumatic SDH. Regarding etiology, 'fall ≥60 years' was the most common category in the entire cohort (n=156; 45% (95% CI 39% to 50%)). The SDH rate was 52/100 000 persons/year (95% CI 47 to 57). The rate of all non-traumatic, non-acute SDH in patients aged ≥18 years was 17/100 000 persons/year (95% CI 15 to 20), combining with 'traumatic' but non-acute fall-related SDH in patients aged ≥60 years yielded 41/100 000 persons/year (95% CI 36 to 47). This demographic may represent an MMAE-eligible population, exceeding large vessel stroke rates (31/100 000 persons/year) in the same population, estimating 139 387 potential MMAE cases/year (95% CI 121 517 to 158 168) in the USA. CONCLUSION: MMAE could transform non-acute SDH management, especially in the elderly, potentially surpassing the impact of large vessel stroke. Clinical trials are essential for validation of its efficacy and safety compared with standard management.

The Impact of Preprocedural Platelet Function Testing on Periprocedural Complication Rates Associated With Pipeline Flow Diversion: An International Multicenter Study.

BACKGROUND AND OBJECTIVES: Dual antiplatelet therapy (DAPT) is necessary to minimize the risk of periprocedural thromboembolic complications associated with aneurysm embolization using pipeline embolization device (PED). We aimed to assess the impact of platelet function testing (PFT) on reducing periprocedural thromboembolic complications associated with PED flow diversion in patients receiving aspirin and clopidogrel. METHODS: Patients with unruptured intracranial aneurysms requiring PED flow diversion were identified from 13 centers for retrospective evaluation. Clinical variables including the results of PFT before treatment, periprocedural DAPT regimen, and intracranial complications occurring within 72 h of embolization were identified. Complication rates were compared between PFT and non-PFT groups. Differences between groups were tested for statistical significance using the Wilcoxon rank sum, Fisher exact, or χ 2 tests. A P -value <.05 was statistically significant. RESULTS: 580 patients underwent PED embolization with 262 patients dichotomized to the PFT group and 318 patients to the non-PFT group. 13.7% of PFT group patients were clopidogrel nonresponders requiring changes in their pre-embolization DAPT regimen. Five percentage of PFT group [2.8%, 8.5%] patients experienced thromboembolic complications vs 1.6% of patients in the non-PFT group [0.6%, 3.8%] ( P = .019). Two (15.4%) PFT group patients with thromboembolic complications experienced permanent neurological disability vs 4 (80%) non-PFT group patients. 3.7% of PFT group patients [1.5%, 8.2%] and 3.5% [1.8%, 6.3%] of non-PFT group patients experienced hemorrhagic intracranial complications ( P > .9). CONCLUSION: Preprocedural PFT before PED treatment of intracranial aneurysms in patients premedicated with an aspirin and clopidogrel DAPT regimen may not be necessary to significantly reduce the risk of procedure-related intracranial complications.

Trial of Early Minimally Invasive Removal of Intracerebral Hemorrhage.

BACKGROUND: Trials of surgical evacuation of supratentorial intracerebral hemorrhages have generally shown no functional benefit. Whether early minimally invasive surgical removal would result in better outcomes than medical management is not known. METHODS: In this multicenter, randomized trial involving patients with an acute intracerebral hemorrhage, we assessed surgical removal of the hematoma as compared with medical management. Patients who had a lobar or anterior basal ganglia hemorrhage with a hematoma volume of 30 to 80 ml were assigned, in a 1:1 ratio, within 24 hours after the time that they were last known to be well, to minimally invasive surgical removal of the hematoma plus guideline-based medical management (surgery group) or to guideline-based medical management alone (control group). The primary efficacy end point was the mean score on the utility-weighted modified Rankin scale (range, 0 to 1, with higher scores indicating better outcomes, according to patients' assessment) at 180 days, with a prespecified threshold for posterior probability of superiority of 0.975 or higher. The trial included rules for adaptation of enrollment criteria on the basis of hemorrhage location. A primary safety end point was death within 30 days after enrollment. RESULTS: A total of 300 patients were enrolled, of whom 30.7% had anterior basal ganglia hemorrhages and 69.3% had lobar hemorrhages. After 175 patients had been enrolled, an adaptation rule was triggered, and only persons with lobar hemorrhages were enrolled. The mean score on the utility-weighted modified Rankin scale at 180 days was 0.458 in the surgery group and 0.374 in the control group (difference, 0.084; 95% Bayesian credible interval, 0.005 to 0.163; posterior probability of superiority of surgery, 0.981). The mean between-group difference was 0.127 (95% Bayesian credible interval, 0.035 to 0.219) among patients with lobar hemorrhages and -0.013 (95% Bayesian credible interval, -0.147 to 0.116) among those with anterior basal ganglia hemorrhages. The percentage of patients who had died by 30 days was 9.3% in the surgery group and 18.0% in the control group. Five patients (3.3%) in the surgery group had postoperative rebleeding and neurologic deterioration. CONCLUSIONS: Among patients in whom surgery could be performed within 24 hours after an acute intracerebral hemorrhage, minimally invasive hematoma evacuation resulted in better functional outcomes at 180 days than those with guideline-based medical management. The effect of surgery appeared to be attributable to intervention for lobar hemorrhages. (Funded by Nico; ENRICH ClinicalTrials.gov number, NCT02880878.).

Most Promising Approaches to Improve Brain AVM Management: ARISE I Consensus Recommendations.

Brain arteriovenous malformations (bAVMs) are complex, and rare arteriovenous shunts that present with a wide range of signs and symptoms, with intracerebral hemorrhage being the most severe. Despite prior societal position statements, there is no consensus on the management of these lesions. ARISE (Aneurysm/bAVM/cSDH Roundtable Discussion With Industry and Stroke Experts) was convened to discuss evidence-based approaches and enhance our understanding of these complex lesions. ARISE identified the need to develop scales to predict the risk of rupture of bAVMs, and the use of common data elements to perform prospective registries and clinical studies. Additionally, the group underscored the need for comprehensive patient management with specialized centers with expertise in cranial and spinal microsurgery, neurological endovascular surgery, and stereotactic radiosurgery. The collection of prospective multicenter data and gross specimens was deemed essential for improving bAVM characterization, genetic evaluation, and phenotyping. Finally, bAVMs should be managed within a multidisciplinary framework, with clinical studies and research conducted collaboratively across multiple centers, harnessing the collective expertise and centralization of resources.

ARISE I Consensus Statement on the Management of Chronic Subdural Hematoma.

ARISE (Aneurysm/AVM/cSDH Roundtable Discussion With Industry and Stroke Experts) organized a one-and-a-half day meeting and workshop and brought together representatives from academia, industry, and government to discuss the most promising approaches to improve outcomes for patients with chronic subdural hematoma (cSDH). The emerging role of middle meningeal artery embolization in clinical practice and the design of current and potential future trials were the primary focuses of discussion. Existing evidence for imaging, indications, agents, and techniques was reviewed, and areas of priority for study and key questions surrounding the development of new and existing treatments for cSDH were identified. Multiple randomized, controlled trials have met their primary efficacy end points, providing high-level evidence that middle meningeal artery embolization is a potent adjunctive therapy to the standard (surgical and nonsurgical) management of neurologically stable cSDH patients in terms of reducing rates of disease recurrence. Pooled data analyses following the formal conclusion and publication of these trials will form a robust foundation upon which guidelines can be strengthened for cSDH treatment modalities and optimal patient selection, as well as delineate future lines of investigation.

The Influence of Coagulopathy on Radiographic and Clinical Outcomes in Patients Undergoing Middle Meningeal Artery Embolization as Standalone Treatment for Non-acute Subdural Hematomas.

Middle meningeal artery embolization (MMAE) is emerging as a safe and effective standalone intervention for non-acute subdural hematomas (NASHs); however, the risk of hematoma recurrence after MMAE in coagulopathic patients is unclear. To characterize the impact of coagulopathy on treatment outcomes, we analyzed a multi-institutional database of patients who underwent standalone MMAE as treatment for NASH. We classified 537 patients who underwent MMAE as a standalone intervention between 2019 and 2023 by coagulopathy status. Coagulopathy was defined as use of anticoagulation/antiplatelet agents or pre-operative thrombocytopenia (platelets <100,000/µL). Demographics, pre-procedural characteristics, in-hospital course, and patient outcomes were collected. Thrombocytopenia, aspirin use, antiplatelet agent use, and anticoagulant use were assessed using univariate and multivariate analyses to identify any characteristics associated with the need for rescue surgical intervention, mortality, adverse events, and modified Rankin Scale score at 90-day follow-up. Propensity score-matched cohorts by coagulopathy status with matching covariates adjusting for risk factors implicated in surgical recurrence were evaluated by univariate and multivariate analyses. Minimal differences in pre-operative characteristics between patients with and those without coagulopathy were observed. On unmatched and matched analyses, patients with coagulopathy had higher rates of requiring subsequent surgery than those without (unmatched: 9.9% vs. 4.3%; matched: 12.6% vs. 4.6%; both p < 0.05). On matched multivariable analysis, patients with coagulopathy had an increased odds ratio (OR) of requiring surgical rescue (OR 3.95; 95% confidence interval [CI] 1.68-9.30; p < 0.01). Antiplatelet agent use (ticagrelor, prasugrel, or clopidogrel) was also predictive of surgical rescue (OR 4.38; 95% CI 1.51-12.72; p = 0.01), and patients with thrombocytopenia had significantly increased odds of in-hospital mortality (OR 5.16; 95% CI 2.38-11.20; p < 0.01). There were no differences in follow-up radiographic and other clinical outcomes in patients with and those without coagulopathy. Patients with coagulopathy undergoing standalone MMAE for treatment of NASH may have greater risk of requiring surgical rescue (particularly in patients using antiplatelet agents), and in-hospital mortality (in thrombocytopenic patients).

General Versus Nongeneral Anesthesia for Middle Meningeal Artery Embolization for Chronic Subdural Hematomas: Multicenter Propensity Score Matched Study.

BACKGROUND AND OBJECTIVES: The choice of anesthesia type (general anesthesia [GA] vs nongeneral anesthesia [non-GA]) in middle meningeal artery embolization (MMAE) procedures for chronic subdural hematomas (cSDH) differs between institutions and left to care team discretion given lack of standard guidelines. We compare the outcomes of GA vs non-GA in MMAE. METHODS: Consecutive patients receiving MMAE for cSDH at 14 North American centers (2018-2023) were included. Clinical, cSDH characteristics, and technical/clinical outcomes were compared between the GA/non-GA groups. Using propensity score matching (PSM), patients were matched controlling for age, baseline modified Rankin Scale, concurrent/prior surgery, hematoma thickness/midline shift, and baseline antiplatelet/anticoagulation. The primary end points included surgical rescue and radiographic success rates (≥50% reduction in maximum hematoma thickness with minimum 2 weeks of imaging). Secondary end points included technical feasibility, procedural complications, and functional outcomes. RESULTS: Seven hundred seventy-eight patients (median age 73 years, 73.2% male patients) underwent 956 MMAE procedures, 667 (70.4%) were non-GA and 280 were GA (29.6%). After running 1:3 PSM algorithm, this resulted in 153 and 296 in the GA and non-GA groups, respectively. There were no baseline/procedural differences between the groups except radial access more significantly used in the non-GA group (P = .001). There was no difference between the groups in procedural technical feasibility, complications rate, length of stay, surgical rescue rates, or favorable functional outcome at the last follow-up. Subsequent 1:1 sensitivity PSM retained the same results. Bilateral MMAE procedures were more performed under non-GA group (75.8% vs 67.2%; P = .01); no differences were noted in clinical/radiographic outcomes between bilateral vs unilateral MMAE, except for longer procedure duration in the bilateral group (median 73 minutes [IQR 48.3-100] vs 54 minutes [39-75]; P < .0001). Another PSM analysis comparing GA vs non-GA in patients undergoing stand-alone MMAE retained similar associations. CONCLUSION: We found no significant differences in radiological improvement/clinical outcomes between GA and non-GA for MMAE.

Transvenous embolization of noncavernous dural arteriovenous fistulas (dAVFs): A systematic review and meta-analysis.

BACKGROUND: Intracranial dural arteriovenous fistulas (dAVFs) are abnormal connections between arteries and veins within the dura mater. Various treatment modalities, such as surgical ligation, endovascular intervention, and radiosurgery, aim to close the fistulous connection. Although transvenous embolization (TVE) is the preferred method for carotid-cavernous fistulas, its description and outcomes for noncavernous dAVFs vary. This has prompted a systematic review and meta-analysis to comprehensively assess the effectiveness of TVE in treating noncavernous dAVFs, addressing variations in outcomes and techniques. METHODS: We searched PubMed and Embase, spanning from the earliest records to December 2022, to identify pertinent English-language articles detailing the utilization of TVE. We focused on specific procedural details, outcomes, and complications in patients older than 18 years. The data collected and analyzed comprised the sample size, number of fistulas, publication specifics, presenting symptoms, fistula grades, and pooled rates of embolizations, outcomes, follow-up information, and complications. RESULTS: From a total of 565 screened articles, 15 retrospective articles encompassing 166 patients spanning across seven countries met the inclusion criteria. Their Newcastle-Ottawa scores ranged from 6 to 8. Intraprocedural complication rate was 10% (95% confidence interval [CI] = 5.9-17.1) and in-hospital postprocedural complication rate was 5.4% (95% CI = 2.8-10.6). Prevalence of in-hospital mortality was 5.5% (95% CI = 2.9-10.6). Complication rate during follow-up was 8.6% (95% CI = 4.7-15.7) with fistula rupture occurring in 5.5% (95% CI = 2.6-11.6) of patients. Complete obliteration rate at final angiographic follow-up was 94.9% (95% CI = 90.3-99.9). Symptoms improved in 95% (95% CI = 89.8-100) of patients at final follow-up. CONCLUSION: To our knowledge, we present the first meta-analysis assessing obliteration rates, outcomes, and complications of TVE for dAVFs. Our analysis highlights the higher (>90%) complete obliteration rates. Large prospective multicenter studies are needed to better define the utility of TVE for noncavernous dAVFs.

A novel swine model of selective middle meningeal artery catheterization and embolization.

BACKGROUND: Middle meningeal artery (MMA) embolization is a promising intervention as a stand-alone or adjunct treatment to surgery in patients with chronic subdural hematomas. There are currently no large animal models for selective access and embolization of the MMA for preclinical evaluation of this endovascular modality. Our objective was to introduce a novel in vivo model of selective MMA embolization in swine. METHODS: Diagnostic cerebral angiography with selective microcatheter catheterization into the MMA was performed under general anesthesia in five swine. Anatomical variants in arterial meningeal supply were examined. In two animals, subsequent embolization of the MMA with a liquid embolic agent (Onyx-18) was performed, followed by brain tissue harvest and histological analysis. RESULTS: The MMA was consistently localized as a branch of the internal maxillary artery just distal to the origin of the ascending pharyngeal artery. Additional meningeal supply was observed from the external ophthalmic artery, although not present consistently. MMA embolization with Onyx was technically successful and feasible. Histological analysis showed Onyx material within the MMA lumen. CONCLUSIONS: Microcatheter access into the MMA in swine with liquid embolic agent delivery represents a reproducible model of MMA embolization. Anatomical variations in the distribution of arterial supply to the meninges exist. This model has a potential application for comparing therapeutic effects of various embolic agents in a preclinical setting that closely resembles the MMA embolization procedure in humans.

Factors Affecting Selection of TraineE for Neurointervention (FASTEN).

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.

Thrombectomy With the pRESET vs Solitaire Stent Retrievers as First-Line Large Vessel Occlusion Stroke Treatment: A Randomized Clinical Trial.

Importance: Stent retriever-based thrombectomy is highly beneficial in large vessel occlusion (LVO) strokes. Many stent retriever designs are currently available, but comparison of these technologies in well-conducted studies is lacking. Objective: To determine whether thrombectomy for LVO stroke with the pRESET stent retriever is noninferior to treatment with the Solitaire stent retriever. Design, Setting, and Participants: This study was a multicenter, prospective, randomized, controlled, open-label, adaptive, noninferiority trial with blinded primary end point evaluation. Between October 2019 and February 2022, multicenter participation occurred across 19 research hospitals and/or universities in the US and 5 in Germany. Patients with LVO stroke were enrolled and included up to 8 hours after symptom onset. Interventions: Patients underwent 1:1 randomization to thrombectomy with the pRESET or Solitaire stent retriever. Main Outcomes and Measures: The primary outcome was the difference in the rate of 90-day functional independence across the 2 devices, using a -12.5% noninferiority margin for the lower bound of the 1-sided 95% CI of the difference between pRESET and Solitaire retrievers. Results: Of 340 randomized patients, 170 (50.0%) were female, and the median (IQR) age was 73.0 (64.0-82.0) years. The study procedure was completed in 322 of the 340 randomized patients. The primary end point of 90-day functional independence was achieved by 95 patients (54.9%; 95% CI, 48.7-61.1) in the pRESET group and in 96 (57.5%; 95% CI, 51.2-63.8) in the Solitaire group (absolute difference, -2.57%; 95% CI, -11.42 to 6.28). As the lower bound of the 95% CI was greater than -12.5%, the pRESET retriever was deemed noninferior to the Solitaire retriever. The noninferiority of pRESET over Solitaire was also observed in the secondary clinical end point (90-day shift in modified Rankin Scale score) and in both angiographic end points (Expanded Treatment in Cerebral Infarction [eTICI] score of 2b50 or greater within 3 passes: 146 of 173 [84.4%] vs 149 of 167 [89.2%]; absolute difference, -4.83%; 95% CI, -10.84 to 1.19; eTICI of 2c or greater following the first pass: 76 of 173 [43.7%] vs 74 of 167 [44.3%]; absolute difference, -0.63%; 95% CI, -9.48 to 8.21). Symptomatic intracranial hemorrhage occurred in 0 patients in the pRESET group and 2 (1.2%) in the Solitaire group. Mortality occurred in 25 (14.5%) in the pRESET group and in 24 (14.4%) in the Solitaire group at 90 days. Findings of the per-protocol and as-treated analyses were in concordance with findings of the intention-to-treat analysis. Conclusions and Relevance: In this study, among patients with LVO stroke, thrombectomy with the pRESET stent retriever was noninferior to thrombectomy with the Solitaire stent retriever. Findings suggest that pRESET offers a safe and effective option for flow restoration and disability reduction in patients with LVO stroke.

Future of Endovascular and Surgical Treatments of Atherosclerotic Intracranial Stenosis.

Intracranial atherosclerotic disease and resultant intracranial stenosis is a global leading cause of stroke, and poses an ongoing treatment challenge. Among patients with intracranial stenosis, those with hemodynamic compromise are at high risk for recurrent stroke despite medical therapy and risk factor modification. Revascularization of the hypoperfused territory is the most plausible treatment strategy for these high-risk patients, yet surgical and endovascular therapies have not yet shown to be sufficiently safe and effective in randomized controlled trials. Advances in diagnostic and therapeutic technologies have led to a resurgence of interest in surgical and endovascular treatment strategies, with a growing body of evidence to support their further evaluation in the treatment of select patient populations. This review outlines the current and emerging endovascular and surgical treatments and highlights promising future management strategies.

MicroCT and Histological Analysis of Clot Composition in Acute Ischemic Stroke : A Comparative Study of MT-Retrieved Clots and Clot Analogs.

PURPOSE: Assessing clot composition on prethrombectomy computed tomography (CT) imaging may help in stroke treatment planning. In this study we seek to use microCT imaging of fabricated blood clots to understand the relationship between CT radiographic signals and the biological makeup. METHODS: Clots (n = 10) retrieved by mechanical thrombectomy (MT) were collected, and 6 clot analogs of varying RBC composition were made. We performed paired microCT and histological image analysis of all 16 clots using a ScanCo microCT 100 (4.9 µm resolution) and standard H&E staining (imaged at 40×). From these data types, first order statistic (FOS) radiomics were computed from microCT, and percent composition of RBCs (%RBC) was computed from histology. Polynomial and linear regression (LR) were used to build statistical models based on retrieved thrombus microCT and %RBC that were evaluated for their ability to predict the %RBC of clot analogs from mean HU. Correlation analyses of microCT FOS with composition were completed for both retrieved clots and analogs. RESULTS: The LR model fits relating MT-retrieved clot %RBC with mean (R2 = 0.625, p = 0.006) and standard deviation (R2 = 0.564, p < 0.05) in HUs on microCT were significant. Similarly, LR models relating analog histological %RBC to analog protocol %RBC (R2 = 0.915, p = 0.003) and mean HUs on microCT (R2 = 0.872, p = 0.007) were also significant. When the LR model built using MT-retrieved clots was used to predict analog %RBC from mean HUs, significant correlation was observed between predictions and actual histological %RBC (R2 = 0.852, p = 0.009). For retrieved clots, significant correlations were observed for energy and total energy with %RBC and %FP (|R| > 0.7, q < 0.01). Analogs further demonstrated significant correlation between FOS energy, total energy, variance and %WBC (|R| > 0.9, q < 0.01). CONCLUSION: MicroCT can be used to build models that predict AIS clot composition from routine CT parameters and help us to better understand radiomic signatures associated with clot composition and first pass outcomes. In future work, such observations can be used to better infer clot composition and inform thrombectomy prognostics from pretreatment CTs.

A propensity score-matched comparative study of balloon guide catheters versus conventional guide catheters for concurrent mechanical thrombectomy with carotid stenting in tandem strokes: comparison of first pass effect, symptomatic intracranial hemorrhage, and 90-day functional outcomes.

BACKGROUND: Extensive clot burden in tandem strokes accounts for poor mechanical thrombectomy (MT) outcomes. Several studies have shown the benefit of balloon guide catheters (BGCs) in MT and carotid artery stenting. OBJECTIVE: In view of this potential benefit, to investigate the safety and effectiveness of proximal flow arrest using a BGC during concurrent MT and carotid revascularization for tandem stroke treatment in a comparative, propensity score-matched (PSM) study. METHODS: Patients with a tandem stroke identified from our endovascular database were dichotomized into groups treated with BGCs versus conventional guide catheters. One-to-one PSM adjustment for baseline demographics and treatment selection bias using nearest-neighbor matching was performed. Patient demographics, presentation characteristics, and procedural details were recorded. Outcomes assessed were final modified Thrombolysis in Cerebral Infarction (mTICI) grade, periprocedural symptomatic intracranial hemorrhage (sICH) rate, in-hospital mortality, and 90-day modified Rankin Scale (mRS) score. Mann-Whitney U test and multivariate logistic regression were performed to compare procedural parameters and clinical outcomes. RESULTS: Concurrent carotid revascularization (stenting with/without angioplasty) and MT was performed in 125 cases (BGC: 85; no BGC: 40). After PSM (40 patients/group), the BGC group had a significantly shorter procedure duration (77.9 vs 61.5 min; OR=0.996; P=0.006), lower discharge National Institutes of Health Stroke Scale score (8.0 vs 11.0; OR=0.987; P=0.042), and higher odds of 90-day mRS 0-2 score (52.3% vs 27.5%; OR=0.34; P=0.040). On multivariate regression, the BGC group had a significantly higher first pass effect rate (mTICI 2b or 3)(OR=1.115, 95% CI 1.015 to 1.432; P=0.013) and lower periprocedural sICH rate (OR=0.615, 95% CI 0.406 to 0.932; P=0.025). No difference in in-hospital mortality was observed (OR=1.591, 95% CI 0.976 to 2.593; P=0.067). CONCLUSION: BGCs used for concurrent MT-carotid revascularization with flow arrest were safe and resulted in superior clinical and angiographic outcomes in patients with a tandem stroke.