Brinjikji, Waleed

Background/Objectives: Idiopathic intracranial hypertension (IIH) often features dural venous sinus stenosis; venous sinus stenting (VSS) improves venous outflow and intracranial pressure, but most stents are off-label, and few are engineered for intracranial venous anatomy. The aim was to synthesize animal models relevant to IIH/VSS, catalogue stents used clinically for VSS and summarize corresponding animal data, appraise current preclinical VSS research, and propose a pragmatic preclinical evaluation framework. Methods: We performed a targeted search (PubMed, Web of Science, Scopus; through to May 2025), dual-screened the records in Nested Knowledge, and extracted the model/device characteristics and outcomes as per the predefined criteria. Results: We identified 65 clinical VSS studies; most were retrospective and used off-label carotid/peripheral/biliary stents (Precise, Zilver, and Wallstent were the most frequent). Recent dedicated systems (River, BosStent) have limited animal evidence; VIVA has GLP porcine venous peripheral data demonstrating its patency, structural integrity, and benign healing outcomes. Rodent models reproduce obesity/androgen drivers with modest, sustained ICP elevation; large animal models show the technical feasibility of in sinus implantation, but no chronic focal venous stenosis model fully mirrors the IIH condition. Conclusions: Despite broad clinical uptake, the translational underpinnings of VSS in IIH remain incomplete: most devices lack intracranial venous-specific preclinical validation, and there is no existing animal model that recapitulates both IIH biology and focal sinus stenosis.

Background Endovascular thrombectomy (EVT) has transformed acute ischemic stroke (AIS) care, with onset-to-puncture (OTP) time widely recognized as a critical determinant of outcome. However, emerging evidence suggests that in-hospital procedure time (PT)—from arterial puncture to final recanalization—may have an equally or more significant impact. This study examines the relative contribution of PT versus OTP to functional outcomes in patients with AIS undergoing EVT. Methods A retrospective analysis was conducted of 6644 patients with AIS treated at 44 international stroke centers from the Stroke Thrombectomy and Aneurysm Registry (STAR; 2016–2023). Multivariable regression, time-equivalence analysis, and marginal effects modeling were used to assess associations between PT, OTP, and 90-day modified Rankin Scale (mRS) outcomes. Centers were stratified by procedural efficiency and compared using propensity score matching (PSM). Mediation analysis evaluated whether PT accounted for inter-center differences. Results PT and OTP were independently associated with functional outcomes; however, PT had a significantly stronger effect (adjusted OR for mRS 0–2: PT=0.56 vs OTP=0.96 per hour). Each 5 min increase in PT was equivalent to 78–100 min of additional OTP in outcome impact. Centers with faster average PT had higher rates of functional independence (number needed to treat (NNT)=10), fewer complications, and lower symptomatic intracranial hemorrhage rates. PT significantly mediated the relationship between center tier and outcomes (Sobel’s P<0.001). Conclusion While minimizing OTP remains important, PT exerts a greater influence on outcomes after EVT. Procedural efficiency should be emphasized in stroke systems of care and included in center performance metrics to improve patient outcomes.

BACKGROUND AND OBJECTIVES: Flow-diverting stents (FDSs) have improved treatment options for intracranial aneurysms. Although FDS have proven successful in treating aneurysms that would previously have required complex microsurgical or endovascular repairs, treatment failures remain a concern. In this multicenter study, we aim to analyze the predictors of residual aneurysmal filling at early angiographic follow-up. METHODS: A retrospective analysis of a prospectively maintained neuroendovascular database at 14 high-volume US centers was conducted for all patients who underwent FDS placement for intracranial aneurysms between 2011 and 2019. Aneurysms were graded on the O'Kelly-Marotta scale (OKM). RESULTS: A total of 2277 patients underwent FDS embolization for intracranial aneurysms during the study period. The patient's mean age was 55 (SD ± 13.5) years, and 82% were female. The median maximal aneurysm diameter was 6.7 mm (IQR 4.10-11 mm). Complete aneurysm obliteration (OKM grade 4) occurred in 1109 patients (68%), and 146 (9%) were OKM grade 3, 188 (12%) were OKM grade 2, and 174 (11%) were OKM grade 1. In the adjusted multivariate analysis, individuals in the 65-74 years and 75+ years age groups had significantly increased risk of residual aneurysm filling at 6-month follow-up compared with the 18-44 years age group (odds ratio [OR] 1.92 (95% CI: 1.33-2.78) and 2.92 (95% CI: 1.79-4.77), respectively). Aneurysms arising from the superior cerebellar artery, the basilar artery, and the carotid terminus were more likely to have a residual filling (OR 12.6, 95% CI: 1.39–14.7; OR 4.27, 95% CI: 1.39–14.7; OR 3.16, 95% CI: 1.24–8.06, respectively). CONCLUSION: As the utilization of FDS for intracranial aneurysms becomes more widespread, the efficacy of aneurysm obliteration needs to be assessed. Our results indicate that several patient-dependent factors, such as age, aneurysm location, and size, predict the likelihood of residual aneurysm filling 6 months post-treatment.

Purpose Aneurysmal rupture and subarachnoid hemorrhage (SAH) have an exceptionally high mortality and morbidity burden. The aim of this study was to develop interpretable machine learning models for predicting short-term poor outcomes defined by the National Inpatient Sample Subarachnoid Hemorrhage Outcome Measure (NIS-SOM). Methods The National Inpatient Sample (NIS) database was queried from 2008 to 2018 to identify patients diagnosed with SAH who had undergone endovascular coiling or clipping for intracranial aneurysm. Demographic, comorbidity, risk factor, and hospital characteristic variables were recorded. Variables were preprocessed, and the feature space was reduced to include the most important features. To predict poor outcomes, machine learning models were trained and cross-validated before being evaluated on a separate testing set. Shapley Additive exPlanations of the best performing model was used for general and local model interpretation. Results Among 18,149 admissions (mean age 55 ± 14 years, 68.8% women), 52.9% had a poor outcome. Test-set AUCs ranged 0.74–0.80; a multilayer perceptron performed best (AUC 0.80, precision 0.74, recall 0.82). SHAP ranked the ten most influential variables: age, neurological comorbidity, paralysis, Medicare insurance, smoking status, Elixhauser burden, fluid-electrolyte disorders, weight loss, arrhythmia, and heart failure. Conclusions The modeling predicted nationwide aSAH prognosis with decent accuracy and highlighted clinical, socioeconomic, and system-level drivers of determinants of poor short-term outcome. These results support the potential of explainable ML tools as complementary tools for early risk stratification, guiding resource allocation, and informing prospective multi-center validation and implementation studies.

Introduction: Endovascular thrombectomy (EVT) is an effective treatment for basilar artery occlusion (BAO) stroke in select patients. While there is a growing body of literature suggesting that advanced imaging modalities such as computed tomography perfusion (CTP) and magnetic resonance (MR) may not be necessary for selecting anterior circulation large vessel occlusion stroke patients for EVT, whether advanced imaging may be superior to conventional imaging (non-contrast CT and CT angiography) in identifying good treatment candidates among BAO patients is less clear. Patients and methods: This was a multicenter retrospective cohort study of BAO EVT patients treated from 2013 to 2022 in the Stroke Thrombectomy and Aneurysm Registry. Patients selected for EVT by advanced imaging (CTP or MR) were matched with those selected by conventional imaging using propensity score matching (PSM) accounting for possible confounders. Primary outcome was functional independence at 90 days. Other outcomes include bedridden state or death at 90-days and symptomatic intracranial hemorrhage (sICH). Results: 268 patients were included. 150 patients were selected for BAO EVT by conventional imaging, 86 by CTP, and 32 by MR. Patients selected by advanced imaging were significantly older than those selected by conventional imaging (median age 71 vs 64 years, p = 0.001); patient characteristics were otherwise similar between cohorts. After PSM, 90-day outcomes were similar between the two cohorts ( p = 0.56), with similar rates of functional independence (39.4% vs 35.1%, p = 0.65), bedridden state or death (40.4% vs 44.7%, p = 0.66), and sICH (3.3% vs 5.7%, p = 0.49) for conventional and advanced imaging groups, respectively. Results were similar across treatment time windows (all p > 0.05). Conclusions: Selecting patients for basilar EVT using conventional versus advanced imaging did not result in different clinical outcomes, regardless of treatment time windows. Conventional imaging appears sufficient as a first-line tool for selecting basilar EVT patients in routine clinical practice.

Objective Cognitive impairment is increasingly recognized in patients with cerebral venous congestion (CVC), yet the cognitive tools used are largely adapted from stroke and dementia research. This review examines current literature on cognitive function in CVC, including conditions such as cerebral venous sinus thrombosis (CVST), idiopathic intracranial hypertension (IIH), and dural arteriovenous fistulas (dAVFs). Special emphasis is placed on the limitations of common screening tools like the Montreal Cognitive Assessment (MoCA) and Mini-Mental State Examination (MMSE). Cognitive dysfunction—primarily affecting executive function, processing speed, and attention—is reported in up to 86% of CVC cases, yet only about 20% of studies use validated cognitive testing tools, most of which may lack sensitivity for CVC-specific deficits. Emerging techniques such as ocular motor testing and physiological markers show promise but require further validation. There is an urgent need for standardized, CVC-specific cognitive assessment protocols that reflect the unique pathophysiology of venous disorders. Future research should prioritize the development of targeted cognitive batteries and integrate objective physiological measures to enhance diagnostic accuracy.

Background Balloon guide catheters (BGCs) are adjunctive devices that may be used during mechanical thrombectomy (MT) to induce flow arrest and improve clot retrieval and reperfusion outcomes for acute ischemic stroke. As the cost-effectiveness of BGC use remains uncertain, this study assessed short- and long-term direct healthcare costs associated with BGC use versus standard guide catheters (SGC) during MT. Methods A decision tree model estimated the short-term costs (index hospitalization), long-term costs (one year after index hospitalization), and total costs for patients undergoing MT + BGC versus MT + SGC from a healthcare system perspective in the United States (US), Canada, United Kingdom (UK), Sweden, Germany, Italy, Spain, Belgium, and The Netherlands. Average device costs were sourced from public tender prices and market research data. Weighted average healthcare costs for modified Rankin Scale scores were sourced from published literature for the respective countries. A 2024 meta-analysis supporting improved outcomes with BGC provided input parameters to model treatment effects for BGC and SGC. Deterministic one-way and probabilistic sensitivity analyses evaluated the robustness of model parameters and accounted for uncertainty. Results Across all countries, long-term and total per-patient costs were lower with MT + BGC, yielding total per-patient cost savings of $6297 (US), CAD 3006 (Canada), £1828 (UK), 28,950 kr (Sweden), €1077 (Germany), €709 (Italy), €3678 (Spain), €2259 (Belgium), and €3344 (The Netherlands). The probability of MT + BGC yielding cost savings ranged 0.356–0.911 (short term), 0.962–0.975 (long term), and 0.838–0.935 (total costs). While long-term and total costs consistently favored MT + BGC, short-term cost savings showed more variability across countries. Conclusion This study demonstrates that BGC use is associated with total one-year per-patient cost savings for inpatient and postdischarge stroke care across the US, Canada, and seven European healthcare systems. Balloon guide catheters can potentially reduce post-stroke care costs and should be considered more broadly, despite the additional cost incurred by the device.