Search Results (361)

Intracranial aneurysms (IAs) represent a major clinical concern due to their risk of rupture and the resulting morbidity and mortality. Both environmental and genetic factors contribute to IA susceptibility, yet the genetic causes of IA remain poorly understood. We previously identified several single nucleotide variants (SNVs) in collagen XXII (COL22A1) in affected individuals with IA. However, the functional impact of these variants has not been determined, and it remains unclear whether and how they increase IA susceptibility. Here, we tested the functional effect of these variants in a zebrafish embryo model. Inducible overexpression of six human COL22A1 SNVs increased the incidence of cranial hemorrhage in zebrafish embryos, while overexpression of wild-type COL22A1 had no significant effect. Overexpression of DNA construct encoding COL22A1 P989L variant disrupted intracranial vascular architecture, leading to reduced vessel length, altered vascular surface parameters, and abnormal arterial patterning. Overexpression of the P989L SNV also caused pronounced vascular leakage, reduced pericyte number, and decreased expression of the tight junction proteins Claudin-5 and ZO-1. P989L SNV overexpression was also associated with increased expression of the endoplasmic reticulum stress marker hspa5. In silico modeling suggested that the P989L variant likely perturbs triple-helix formation in COL22A1, thereby causing protein misfolding and compromising its function. Together, these findings demonstrate the deleterious effects of IA-associated COL22A1 variants on vascular function and stability and suggest that these variants may increase the incidence of IA in humans. Full article

Objective: To evaluate whether ABO blood group is associated with venous thromboembolic events (VTEs), cerebral severe vasospasm (CSV), delayed cerebral ischemia (DCI), and clinical or cognitive outcomes after aneurysmal subarachnoid hemorrhage (aSAH). Materials and Methods: A retrospective observational two-center cohort study of collected registry data, including 169 patients treated between September 2021 and November 2025. Outcomes were compared across ABO subtypes using univariate testing and multivariable logistic regression. Results: No ABO subtype was independently associated with VTE (7.7%), CSV/DCI (21.9%), intracranial hemorrhage, or in-hospital mortality (all p > 0.05). Higher age (OR 1.08, 95% CI 1.031–1.144, p = 0.003) was independently associated with increased in-hospital mortality, whereas single peri-interventional antiplatelet therapy (PIAT) (OR 0.076, 95% CI 0.004–0.506, p = 0.029) was associated with lower in-hospital mortality. ABO blood group was not associated with functional outcome (mRS) or cognitive performance (MoCA) in this cohort. Conclusions: In this two-center retrospective cohort, no independent association between ABO blood group and early cerebrovascular complications, functional outcome, or cognitive outcome after aSAH was detected. These findings suggest that short-term prognosis may be more strongly influenced by established patient- and treatment-related factors, particularly age and single PIAT. Further studies with larger cohorts are warranted to clarify the potential effect of ABO blood group on outcomes after aSAH. Full article

Cerebrovascular diseases, including stroke and intracranial aneurysm, affect millions worldwide and remain a leading cause of mortality and disability. Time-of-Flight Magnetic Resonance Angiography (TOF-MRA) enables non-invasive visualization of intracranial arteries. However, the complex cerebrovascular anatomy, characterized by variable diameters, tortuous trajectories, and intricate branching, renders manual segmentation time-consuming, subjective, and prone to inter-observer variability. While deep learning models achieve strong segmentation performance, existing 3D approaches typically require millions of parameters, limiting deployment in resource-constrained clinical settings. To address this challenge, this paper proposes a Lightweight Intracranial Vascular Segmentation Network (LIVAS-Net), a parameter-efficient 3D encoder–decoder architecture using 3D Ghost convolution modules. It incorporates a novel Vessel Continuity Refinement Branch (VCRB), which aims to correct discontinuities in logit space through per-voxel learnable gating. Two model variants are introduced, LIVAS-Net (129K parameters, 18.3 GFLOPs) and LIVAS-L Net (2.97M parameters, 87.8 GFLOPs), achieving 7.9× and 1.6× fewer FLOPs than the standard 3D U-Net (144.5 GFLOPs), respectively. Evaluation on the multi-center COSTA benchmark shows a DSC of 0.8943 (HD95: 1.97 mm) and 0.9235 (HD95: 0.77 mm) on the ADAM test set, outperforming 3D U-Net (DSC: 0.8762). Cross-center evaluation on three external COSTA datasets yields overall DSCs of 0.7834 and 0.7967 versus 0.6998 for 3D UNet. Further evaluation on the CereVessMRA dataset (N = 271) reveals that LIVAS-Net achieves the highest DSC (0.669), demonstrating promising experimental results warranting future clinical validation in resource-constrained settings. Full article

Background/Objectives: Immune-inflammatory activation is a central feature of aneurysmal subarachnoid hemorrhage (aSAH), yet the epitranscriptomic mechanisms underlying this response remain insufficiently understood. This study aimed to investigate RNA methylation-associated immune dysregulation in aSAH and to identify potential biomarkers and signaling pathways. Methods: Four Gene Expression Omnibus datasets were analyzed to characterize RNA methylation regulator-related immune alterations in aSAH. Single-sample gene set enrichment analysis (ssGSEA), weighted gene co-expression network analysis (WGCNA), and intersection with ImmPort immune genes were used to identify candidate genes. A total of 159 machine learning combinations were evaluated for model construction and external validation. Two-sample Mendelian randomization, single-cell RNA sequencing (scRNA-seq), and CellChat analyses were further performed. Peripheral blood samples from patients with aSAH (n = 12) and matched healthy controls (n = 12) were used for total m6A quantification and quantitative real-time PCR (qRT-PCR) validation, while Western blotting and immunofluorescence were used to validate the protein expression of LIFR, GP130, IGF2BP2, and RBM15B. Results: Eleven RNA methylation regulators were differentially expressed between aSAH and controls in GSE122897. The WGCNA module most strongly associated with RNA methylation regulator-related scores was enriched in immune response and myeloid activation pathways. Intersection analysis identified 25 candidate immune-inflammatory genes associated with RNA methylation regulator-related transcriptional patterns. Among 159 algorithms, an XGBoost-LASSO pipeline selected oncostatin M (OSM) as the key variable, and the resulting RNA methylation regulator-related immune-derived gene signature (RMRIGS) showed good discrimination between aSAH and controls across training and validation cohorts. Mendelian randomization supported a protective association of genetically predicted OSM expression with subarachnoid hemorrhage risk (IVW OR = 0.66, p = 0.014). Single-cell analysis showed that Osm was predominantly enriched in infiltrating Ccr2+ macrophages, whereas Lifr and Il6st were broadly expressed in activated microglial subpopulations, indicating the presence of an Osm − (Lifr + Il6st) communication axis after SAH. Clinically, total m6A levels were increased in peripheral blood samples from patients with aSAH, and OSM, together with several RNA methylation regulators, was upregulated and associated with m6A-related changes. In experimental models, the protein expression levels of LIFR, GP130, IGF2BP2, and RBM15B were all increased after SAH-related stimulation. Conclusions: RNA methylation programs may be involved in immune dysregulation in aSAH. The OSM-centered RMRIGS was associated with disease status and may provide insight into the interaction between peripheral immune activation and post-SAH neuroinflammation. The potential involvement of the OSM–LIFR/GP130 signaling axis and its association with RNA methylation regulator-related alterations warrant further investigation. Full article

Background and Purpose: The integration of flow diverter (FD) treatment into hybrid operating rooms (HORs) raises concerns regarding radiation safety, especially when transitioning from biplane systems to single-plane configurations. In this study, we evaluated the impact of distinct procedural-imaging configurations on patient radiation exposure during FD treatment for unruptured cerebral aneurysms. Methods: We retrospectively reviewed 93 patients (HOR: 22; biplane neuroangiography suite [NIS]: 71) treated between 2020 and 2024. Key metrics included fluoroscopy time (FT) and dose area product (DAP), subdivided into 2D fluoroscopy and 3D rotational angiography (3D-RA). Linear regression was used to identify independent predictors of radiation dose. Results: While the HOR significantly reduced fluoroscopy time (19.3 vs. 26.1 min, p = 0.002), it was associated with a higher total DAP compared to the NIS (299.1 vs. 96.3 Gy·cm², p < 0.001). This increase was primarily driven by a substantially higher radiation dose delivered per 3D-RA acquisition in the HOR environment rather than an increased frequency of 3D imaging. Multivariate analysis confirmed that the surgical imaging configuration was the dominant factor influencing total radiation exposure rather than aneurysm complexity or patient characteristics. Conclusions: Hybrid ORs provide procedural efficiency but involve a significant risk of increased radiation dose due to the reliance on 3D imaging for single-plane navigation. These findings serve as preliminary institutional benchmark data, underscoring the need for adaptive radiation management and configuration-specific protocols to optimize patient safety across diverse surgical imaging suites. Full article

Background: The coincidence of unruptured cerebral aneurysms in acute ischemic stroke (AIS) is well known; however evidence on causality remains unclear. In this paper we are aiming to highlight key imaging characteristics that can aid in establishing or excluding a causative relationship between the two entities. Methods: Eight symptomatic patients with ischemic stroke and presence of an aneurysm in the same vascular territory were retrospectively analyzed. The patients were evaluated with computed tomography (CT) or magnetic resonance imaging (MRI) and depending on initial imaging findings, patients received either digital subtraction angiography (DSA) and MRI or MRI alone, with or without vessel wall imaging (VWI). Eligible patients received mechanical thrombectomy (MT) and the rest were managed conservatively. Results: The analysis of the imaging findings led to a proposed framework for classification/characterization of aneurysm as a possible, probable or improbable cause of AIS. The main findings used to categorize the aneurysmatic lesions were aneurysm thrombosis, positive vessel wall imaging, location and presence of comorbidities. Depending on the category the aneurysm was classified in, a decision regarding conducting treatment or not was made. Conclusions: Detailed observation of traditional imaging along with advanced MRI sequences like VWI can potentially help stratify the probability of aneurysms being the source of thromboembolic events. Full article

Background/Objectives: Recent studies have increasingly focused on the morphological characteristics of surrounding arteries as rupture predictors, particularly because these vessel configurations remain stable before and after aneurysm rupture, providing a reliable anatomical substrate for risk assessment. This study aimed to identify independent predictors of rupture by evaluating both aneurysmal and internal carotid artery (ICA) morphological characteristics. Methods: We retrospectively analyzed imaging data from 64 patients with posterior communicating artery (PcomA) aneurysms who underwent treatment at a single tertiary center between 2018 and 2022, including 25 ruptured aneurysms (39.1%). Only treated aneurysms were included to ensure the availability of high-quality pre-treatment digital subtraction angiography (DSA) suitable for three-dimensional (3D) reconstruction and centerline-based analysis. Seventeen aneurysm morphological parameters and thirteen ICA-related parameters were measured. Because time-to-event data were not available, logistic regression analysis was performed with rupture status as the outcome variable. Receiver operating characteristic (ROC) curve analyses were conducted to evaluate discriminative performance. Results: Multivariate logistic regression revealed that three ICA-associated factors—the tortuosity of the communicating ICA segment (Tcco), the ICA cross-sectional area at the PcomA origin (Pcs), and the angle between the ICA and PcomA (θ2)—were independently associated with rupture. Among aneurysm-related factors, Maximum 3D Diameter remained significantly related to rupture risk. ROC analyses demonstrated that Maximum 3D Diameter had the highest discriminative value (AUC 0.779; cut-off 7.805 mm), followed by Pcs, Tcco, and θ2. Conclusions: Both aneurysm morphology and the anatomical configuration of surrounding arteries significantly contribute to rupture risk in PcomA aneurysms. Incorporating parent-vessel morphological features into rupture-risk assessment may enhance patient-specific decision-making. Full article

Background/Objectives: Oculomotor nerve palsy (OMNP) is a clinically significant condition that may represent the earliest manifestation of life-threatening intracranial pathology, particularly aneurysmal compression or neoplasia. Despite its neurosurgical relevance, comprehensive meta-analytic evidence synthesizing OMNP etiologies, clinical presentation, and contemporary diagnostic pathways remains limited. Methods: Following PRISMA 2020 guidelines, MEDLINE, Scopus, and Web of Science were systematically searched for studies reporting quantitative data on OMNP. Pooled prevalence estimates were calculated using random-effects models for causes and symptoms, while a structured narrative synthesis was performed for diagnostic modalities because outcome reporting was heterogeneous and unsuitable for meta-analysis. Risk of bias was assessed using the Joanna Briggs Institute (JBI) risk of bias tool. Results: Twenty-four studies involving 5541 patients were included. Using a multivariate multilevel model to account for within-study dependence, the most common etiological category was vascular disorders (35.62%), followed by idiopathic (16.47%) and neoplastic (12.10%). Head trauma and aneurysms accounted for 11.26% and 10.08% of cases, respectively. Diplopia (60.63%) and ptosis (54.12%) remained the predominant clinical symptoms, while pupil involvement was identified in 40.62% of the pooled population. Diagnostic paradigms have shifted decisively toward non-invasive neuroimaging, with magnetic resonance imaging reported in 66% of included studies and magnetic resonance or computed tomographic angiography increasingly employed to identify surgically relevant vascular lesions. Conclusions: Although vascular disorders represented the most common etiological category, the notable prevalence of aneurysmal and neoplastic causes underscores the importance of prompt high-resolution neuroimaging and early neurosurgical assessment. Early recognition and etiological stratification remain essential to optimize management and prevent irreversible neurological morbidity. Full article

Background: The introduction of flow diverters (FDs) has greatly enhanced the treatment of cerebral aneurysms. This study compares two FDs, the Pipeline Embolization Device (PED) and the Derivo Embolization Device (DED), in terms of technical, angiographic and clinical aspects. Methods: A total of 103 patients with unruptured aneurysms were treated with the PED (n = 56) and DED (n = 47) between 2012 and 2019. Aneurysm occlusion, procedural complications, occurrence of In-stent stenosis and clinical outcome were evaluated retrospectively. Results: Implantation of the flow diverters was technically successful in all patients. There were no significant differences between baseline characteristics and aneurysm morphology. Angiographic follow-up was available with a median short-term follow-up of 3 months and a median long-term follow-up time of 16 months. Adequate aneurysm occlusion at long-term follow-up was substantially but not significantly greater with the DED (95.8%, 45/47) compared to the PED (87.5%, 49/56) (p = 0.084). In-stent stenoses were significantly less frequent with the DED (29.8%; 14/47) than with the PED (53.6%, 30/57) at short-term follow-up (p = 0.017), although moderate and asymptomatic overall. Thromboembolic or hemorrhagic events occurred in 10.7% (6/56) of cases with the PED and 8.5% (4/47) with the DED (p = 0.752). Morbidity rates were similar between devices (PED 3.6% (2/56), DED 2.1% (1/47), p = 1.0). There was no procedural mortality. Conclusions: Clinical outcomes and complications were comparable between the PED and DED while aneurysm occlusion was considerably greater at long-term follow-up and in-stent stenosis significantly less frequent at short-term follow-up with the DED. The surface-modified design of the DED may contribute to reduced thrombogenicity and early advantages in preventing in-stent stenosis. Further comparative studies are necessary to investigate these findings, particularly comparing surface-modified flow diverters with newer-generation devices featuring true coatings. Full article

Intracranial aneurysms are common vascular lesions with a highly variable natural history. While most unruptured intracranial aneurysms remain stable throughout life, a biologically aggressive subset progresses to growth and rupture, resulting in aneurysmal subarachnoid hemorrhage with substantial morbidity and mortality. Contemporary evidence demonstrates that aneurysm behavior is dynamic rather than static and reflects the interaction of hemodynamic forces, inflammatory vascular remodeling, genetic susceptibility, and environmental risk factors. Rupture risk is not constant over time and may be highest early after aneurysm formation, followed by a period of relative quiescence in selected lesions. Traditional population-based risk estimates have therefore evolved toward individualized risk stratification incorporating aneurysm size, location, morphology, growth, patient-specific factors, and emerging imaging and computational biomarkers. This chapter reviews the epidemiology, pathobiology, growth patterns, and rupture risk of intracranial aneurysms, integrating foundational observational studies with recent advances in genetics, vessel wall imaging, and predictive modeling. Understanding the natural history of brain aneurysms is essential for balancing the risks of observation against intervention and for guiding future innovations in aneurysm management. Full article

Background: The risk stratification of unruptured intracranial aneurysms (UIAs) relies largely on static clinical and morphological parameters, which may not fully capture aneurysm-specific wall behavior. ECG-gated four-dimensional computed tomography angiography (4D-CTA) enables the time-resolved assessment of aneurysm wall motion, but reliable interpretation requires the differentiation of biological motion from measurement uncertainty. Methods: In this prospective exploratory pilot study, ECG-gated 4D-CTA was used to evaluate the longitudinal aneurysm size change, global volumetric pulsation (GVP), spatial wall pulsation (SWP), intrinsic wall deformability and variability. Size change and pulsation were defined using predefined resolution- and noise-based thresholds. Spatial wall motion was assessed using phase-resolved three-dimensional displacement maps. Harmonic modeling isolated periodic pulsation, and residual variability exceeding empirically derived uncertainty limits was conservatively interpreted as deformability. Associations with aneurysm growth and ELAPSS scores were analyzed using exploratory statistics. Results: Eleven UIAs in ten patients were followed for 4.3 ± 1.1 years. A longitudinal size change occurred in six aneurysms (54.5%). Baseline GVP was present in eight aneurysms (73%) and SWP in nine (82%). GVP was not associated with a size change (p = 1.00). All aneurysms with a size change exhibited baseline SWP, whereas no size change was observed in aneurysms without SWP; however, this association did not reach statistical significance in this small exploratory cohort (p = 0.18). Conservative variability metrics were not associated with growth but correlated with baseline shape irregularity, particularly the undulation index (Spearman’s ρ up to ~0.90). Conclusions: In this small exploratory pilot cohort, spatial wall pulsation showed a descriptive directional pattern with longitudinal aneurysm size changes, whereas global volumetric pulsation did not. These findings are preliminary, should be interpreted cautiously, and require confirmation in larger, adequately powered longitudinal studies before clinical application. Full article

Aneurysmal subarachnoid hemorrhage (SAH) remains a devastating cerebrovascular disorder with high morbidity and mortality, despite advances in aneurysm securing and neurocritical care. Clinical outcomes are determined by early brain injury (EBI), delayed cerebral ischemia (DCI), hydrocephalus, and long-term cognitive impairment, extending beyond the traditional focus on large-vessel vasospasm alone. Emerging evidence identifies the dysfunction of the glymphatic system and meningeal lymphatic pathway, the brain’s primary clearance pathways, as a central and unifying mechanism linking acute hemorrhagic injury to delayed and chronic neurological sequelae. Following SAH, acute intracranial pressure elevation, subarachnoid blood clot burden, loss of arterial pulsatility, venous congestion, astrocytic aquaporin-4 perivascular depolarization, and neuroinflammation converge to suppress cerebrospinal fluid–interstitial fluid exchange and outflow in glymphatic system and subsequent meningeal lymphatic drainage. Persistent clearance failure promotes the retention of blood breakdown products, inflammatory mediators, and metabolic waste, amplifying microvascular dysfunction, cortical spreading depolarizations, blood–brain barrier disruption, and secondary ischemic injury. Importantly, accumulating data highlight venous pathology and meningeal lymphatic impairment as critical, yet underappreciated, contributors to delayed injury and post-SAH hydrocephalus. In this review, we synthesize the current knowledge of the physiological organization of glymphatic and meningeal lymphatic systems, delineate the mechanistic and molecular drivers of their dysfunction after SAH, and discuss clinical implications for EBI, DCI, hydrocephalus, and long-term cognitive outcomes. We further outline future directions, including translational imaging, biomarker development, and therapeutic strategies targeting clearance pathways, to advance disease-modifying approaches in SAH. Full article

Vascular intervention has advanced technically faster than it has matured methodologically. Across neurovascular, carotid, peripheral, and aortic practice, complications and outcomes are often reported using different definitions, thresholds, surveillance strategies, adjudication methods, follow-up schedules, and units of analysis. As a result, studies that appear to assess the same treatment may in fact be measuring different outcome constructs. This problem is particularly visible in neurovascular intervention, where technical, radiographic, and clinical outcomes are often combined within the same evaluative framework. In acute ischemic stroke thrombectomy, changes in reperfusion thresholds can alter the meaning of procedural success. In intracranial aneurysm treatment, angiographic occlusion, retreatment, delayed stenosis, and neurological morbidity are often reported together despite representing different dimensions of efficacy and safety, while the interpretation of surrogate angiographic outcomes may vary across device classes. Similar issues arise in carotid intervention, peripheral endovascular therapy, and endovascular aneurysm repair, where composite outcomes, imaging-detected complications, and inconsistent surveillance protocols further complicate interpretation. These variations limit cross-study comparability, weaken meta-analytic synthesis, and may distort judgments about treatment effectiveness and safety. Endpoint heterogeneity persists partly through disciplinary silos, device-driven evaluation frameworks, and regulatory pathways that favor surrogate over clinical endpoints; addressing it will require not only better reporting but standardized outcome constructs, coordinated international registries, and broader adoption of core outcome set methodology. Greater discipline in endpoint definition and reporting, together with broader adoption of standardized outcome frameworks and core outcome set methodology, is needed if evidence in vascular intervention is to accumulate coherently. Full article

Rupture of Intracranial Aneurysms (IAs) is the leading cause of non-traumatic intracranial hemorrhage. Early detection of aneurysms prior to rupture or their prompt identification in cases of intracranial hemorrhage is critical and guides treatment strategies. The development of artificial intelligence tools to automate the labor-intensive detection and analysis of IAs is an active research field, but it depends on the availability of large, well-curated datasets for robust model training, validation, and testing. Collaborative data sharing is essential for advancing this field, yet remains relatively uncommon. Here, we present a collection of 172 Computed Tomography Angiography (CTA) scan series—a widely available and commonly used modality for the diagnosis of IAs—supplemented with structured metadata. The dataset comprises 90 scans from healthy patients and 82 scans from patients with IAs of diverse shapes, sizes, and anatomical locations, annotated and validated by two experts. The annotations include 122 surface mesh models in STL format. This openly accessible dataset is intended to support the development of automated segmentation or classification tools, medical image analysis, and assessment of disease progression risks through morphometric and hemodynamic evaluations. Full article

Background: Endovascular treatment has become the major choice for treating intracranial aneurysm (IA). The development of novel endovascular devices for IA treatment is, therefore, socially important. For this purpose, a preclinical animal model to test a prototype of devices plays a crucial role. The major problems regarding currently used preclinical animal models, mainly in medium-to-large animals, are the expense and the lack of IA pathology, as they only mimic the morphological aspect. Methods: Sprague–Dawley rats were used, and the new bifurcation was formed via end-to-side anastomosis of carotid arteries. An aneurysm lesion induced at the newly formed bifurcation site was macroscopically assessed. Endovascular coiling of the induced aneurysm was then done. Results: An aneurysm lesion with a balloon-like shape, as in human cases, was induced at the newly formed bifurcation site. Some of the induced lesions spontaneously ruptured. Endovascular coiling was successfully done by using the micro-catheter and coil used at the clinical site. Conclusions: The rat model of IAs established here provides a novel platform contributing to the development of endovascular devices to treat IAs and, therefore, significantly facilitates the development of devices to achieve more effective treatment. Full article