Changes in case fatality of aneurysmal subarachnoid haemorrhage over time, according to age, sex, and region: a meta-analysis

Therapeutic potential of stem cells in subarachnoid hemorrhage

Aneurysm rupture can result in subarachnoid hemorrhage, a condition with potentially severe consequences, such as disability and death. In the acute stage, early brain injury manifests as intracranial pressure elevation, global cerebral ischemia, acute hydrocephalus, and direct blood-brain contact due to aneurysm rupture. This may subsequently cause delayed cerebral infarction, often with cerebral vasospasm, significantly affecting patient outcomes. Chronic complications such as brain volume loss and chronic hydrocephalus can further impact outcomes. Investigating the mechanisms of subarachnoid hemorrhage-induced brain injury is paramount for identifying effective treatments. Stem cell therapy, with its multipotent differentiation capacity and anti-inflammatory effects, has emerged as a promising approach for treating previously deemed incurable conditions. This review focuses on the potential application of stem cells in subarachnoid hemorrhage pathology and explores their role in neurogenesis and as a therapeutic intervention in preclinical and clinical subarachnoid hemorrhage studies.

Subarachnoid haemorrhage and intracranial aneurysms in Greenland in the period 2018-2021: incidence, outcome and familial disposition

Subarachnoid haemorrhages (SAH) caused by rupture of intracranial aneurysms (IA) are a severe condition. Earlier studies found a higher incidence of SAH in Greenlandic patients compared to Danish patients, with familial aggregation also higher in Greenland. However, updated data is lacking. To investigate the contemporary incidence, outcome, and familial disposition of SAH/IA in Greenlandic patients in 2018-2021. Greenlandic patients diagnosed with ruptured or unruptured IA (UIA) during 2018-2021 were included. Data was obtained from patient files, x-ray department, and discharge registry. Incidence rates were estimated as cases/100,000/year. Direct age-standardised incidence rates were calculated using WHO 2000-2025 as standards. Of 30 SAH patients, 20 (66.7%) were females, 10 (33.3%) males. Of 36 UIA patients, 27 (75.0%) were females, 9 (25.0%) males. For SAH, crude incidence was 13.4/100,000/year, age-standardised incidence was 10.8/100,000/year. Familial history was observed in 30.0% of SAH patients. 5 patients (16.7%) died before treatment, 28-day case-fatality rate (CFR) for all patients was 23.3%. Overall and age-standardised incidence rates were similar to previous studies but higher among females and compared to neighbouring countries. A high occurrence of familial history was reported. SAH remains a serious condition in Greenland, as evidenced by five fatalities before treatment was administered.

Impact of frailty on post-operative outcomes following subarachnoid hemorrhage: A systematic review and meta-analysis

BACKGROUND

Subarachnoid hemorrhage (SAH) is associated with high rates of mortality and morbidity, particularly among elderly patients. The presence of frailty may impact survival rates in patients with SAH. In this study, we aim to investigate the impact of frailty on the clinical outcomes in SAH patients.

METHODS

We conducted a systematic review and meta-analysis following the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. Relevant papers through December 2023 were retrieved from PubMed, Scopus, Web of science, and Embase.

RESULTS

A total of 5 studies met inclusion/exclusion criteria with an aggregate 39,221 non-frail patients (mean age 52.4 ± 5.2 yr; 62.1 % Female), and 79,416 frail patients (mean age 61.1 ± 5.4 yr; 69.0 % Female). Frailty was significantly associated with higher mortality ratio (Odds ratio (OR)= 2.09; CI [1.04: 4.20], p= 0.04), and increased length of hospital stay (OR= 1.40; CI [1.07: 1.83], p= 0.015). Additionally, frailty was associated with higher odds of external ventricular drain insertion, the need of tracheostomy/endoscopic gastrostomy, increased risk of deep vein thrombosis, and postoperative neurological complications.

CONCLUSION

Frailty is associated with worse clinical outcomes and higher mortality rates in SAH patients. Our findings highlight that frailty, when considered alongside other established prognostic factors, serves as crucial predictor for peri-operative complications and overall hospital course in SAH patients.

Association of Fluid Balance and Hemoglobin Decline With Neurological Outcome After Aneurysmal Subarachnoid Hemorrhage

OBJECTIVES

To explore the relationship between fluid balance and hemoglobin decline with secondary infarctions and neurologic outcome in aneurysmal subarachnoid hemorrhage (aSAH) patients.

DESIGN

Secondary analysis of the Earlydrain trial, a prospective randomized controlled study investigating prophylactic lumbar drain use in aSAH patients.

SETTING

Patients with aSAH treated in ICUs at 19 tertiary hospitals in Germany, Switzerland, and Canada.

PATIENTS

From January 2011 to January 2016, 287 patients were enrolled in the Earlydrain trial. Only files with complete information on both daily hemoglobin and balance values were used, leaving 237 patients for analysis.

INTERVENTIONS

Investigation of fluid balance management and hemoglobin levels during the initial 8 days post-aSAH to establish thresholds for unfavorable outcomes and assess their impact on secondary infarctions and 6-month neurologic outcome on the modified Rankin Scale (mRS).

MEASUREMENTS AND MAIN RESULTS

Patients with unfavorable outcome after 6 months (mRS > 2) showed greater hemoglobin decline and increased cumulative fluid balance. A significant inverse relationship existed between fluid balance and hemoglobin decline. Thresholds for unfavorable outcome were 10.4 g/dL hemoglobin and 4894 mL cumulative fluid balance in the first 8 days. In multivariable analysis, fluid balance, but not fluid intake, remained significantly associated with unfavorable outcome, while the influence of hemoglobin lessened. Fluid balance but not hemoglobin related to secondary infarctions, with the effect being significant after inverse probability of treatment weighting. Transfusion was associated with unfavorable outcomes.

CONCLUSIONS

Increased fluid balance influences hemoglobin decline through hemodilution. Fluid overload, rather than a slight decrease in hemoglobin levels, appears to be the primary factor contributing to poor outcomes in aSAH patients. The results suggest aiming for euvolemia and that a modest hemoglobin decline may be tolerated. It may be advisable to adopt a restrictive approach to transfusions, as they can potentially have a negative effect on outcome.

Microglia aggravate white matter injury via C3/C3aR pathway after experimental subarachnoid hemorrhage

The activation of glial cells is intimately associated with the pathophysiology of neuroinflammation and white matter injury (WMI) during both acute and chronic phases following subarachnoid hemorrhage (SAH). The complement C3a receptor (C3aR) has a dual role in modulating inflammation and contributes to neurodevelopment, neuroplasticity, and neurodegeneration. However, its impact on WMI in the context of SAH remains unclear. In this study, 175 male C57BL/6J mice underwent SAH through endovascular perforation. Oxyhemoglobin (oxy-Hb) was employed to simulate SAH in vitro. A suite of techniques, including immunohistochemistry, transcriptomic sequencing, and a range of molecular biotechnologies, were utilized to evaluate the activation of the C3-C3aR pathway on microglial polarization and WMI. Results revealed that post-SAH abnormal activation of microglia was accompanied by upregulation of complement C3 and C3aR. The inhibition of C3aR decreased abnormal microglial activation, attenuated neuroinflammation, and ameliorated WMI and cognitive deficits following SAH. RNA-Seq indicated that C3aR inhibition downregulated several immune and inflammatory pathways and mitigated cellular injury by reducing p53-induced death domain protein 1 (Pidd1) and Protein kinase RNA-like ER kinase (Perk) expression, two factors mainly function in sensing and responding to cellular stress and endoplasmic reticulum (ER) stress. The deleterious effects of the C3-C3aR axis in the context of SAH may be related to endoplasmic reticulum (ER) stress-dependent cellular injury and inflammasome formation. Agonists of Perk can exacerbate the cellular injury and neuroinflammation, which was attenuated by C3aR inhibition after SAH. Additionally, intranasal administration of C3a during the subacute phase of SAH was found to decrease astrocyte reactivity and alleviate cognitive deficits post-SAH. This research deepens our understanding of the complex pathophysiology of WMI following SAH and underscores the therapeutic potential of C3a treatment in promoting white matter repair and enhancing functional recovery prognosis. These insights pave the way for future clinical application of C3a-based therapies, promising significant benefits in the treatment of SAH and its related complications.

Case fatality and functional outcome after spontaneous subarachnoid haemorrhage: A systematic review and meta-analysis of time trends and regional variations in population-based studies

INTRODUCTION

A previous systematic review of population-based studies from 1973 to 2002 found a decrease in case fatality for spontaneous subarachnoid haemorrhage, but could not find a sufficient number of studies to assess changes in functional outcome. Since then, treatment has advanced distinctly. We assessed whether case fatality has decreased further and whether functional outcome has improved.

PATIENTS AND METHODS

We searched PubMed and Web of Science for new population-based studies using the same criteria as in our previous systematic review. We assessed changes in case fatality and functional outcome over time using linear regression.

RESULTS

We included 24 new studies with 827 patients and analysed 9542 patients described in 62 study periods between 1973 and 2017. Case fatality decreased by 0.3% (95% CI: -0.7 to 0.1) per year. In a sensitivity analysis excluding studies that did not provide 1-month outcome and outliers, the age and sex-adjusted decrease was 0.1% per year (95% CI: -0.9 to 0.6). The mean case fatality rate decreased from 47% (95% CI: 31-63) in the 1970s to 35% (95% CI: 30-39) in the 1990s, and remained stable in the 2000s (34%; 95% CI: 27-41) and 2010s (38%; 95% CI: 15-60). In 15 studies, the mean proportion of patients living independently increased by 0.2% per year (95%CI: -0.7 to 1.1) and the mean was 45% (95% CI: 39-50) in six studies that reported outcome after 12 months.

DISCUSSION AND CONCLUSION

From 1973 to 2017, the case-fatality rate of spontaneous subarachnoid haemorrhage declined overall by 13.5%, but remained stable over the last two decades. The data on time trends in functional outcome were inconclusive.

Identification of key genes and immune infiltration in peripheral blood biomarker analysis of delayed cerebral ischemia: Valproic acid as a potential therapeutic drug

BACKGROUND

Delayed cerebral ischemia (DCI) is a common and serious complication of subarachnoid hemorrhage (SAH). Its pathogenesis is not fully understood. Here, we developed a predictive model based on peripheral blood biomarkers and validated the model using several bioinformatic multi-analysis methods.

METHODS

Six datasets were obtained from the GEO database. Characteristic genes were screened using weighted correlation network analysis (WGCNA) and differentially expressed genes. Three machine learning algorithms, elastic networks-LASSO, support vector machines (SVM-RFE) and random forests (RF), were also used to construct diagnostic prediction models for key genes. To further evaluate the performance and predictive value of the diagnostic models, nomogram model were constructed, and the clinical value of the models was assessed using Decision Curve Analysis (DCA), Area Under the Check Curve (AUC), Clinical Impact Curve (CIC), and validated in the mouse single-cell RNA-seq dataset. Mendelian randomization(MR) analysis explored the causal relationship between SAH and stroke, and the intermediate influencing factors. We validated this by retrospectively analyzing the qPCR levels of the most relevant genes in SAH and SAH-DCI patients. This experiment demonstrated a statistically significant difference between SAH and SAH-DCI and normal group controls. Finally, potential small molecule compounds interacting with the selected features were screened from the Comparative Toxicogenomics Database (CTD).

RESULTS

The fGSEA results showed that activation of Toll-like receptor signaling and leukocyte transendothelial cell migration pathways were positively correlated with the DCI phenotype, whereas cytokine signaling pathways and natural killer cell-mediated cytotoxicity were negatively correlated. Consensus feature selection of DEG genes using WGCNA and three machine learning algorithms resulted in the identification of six genes (SPOCK2, TRRAP, CIB1, BCL11B, PDZD8 and LAT), which were used to predict DCI diagnosis with high accuracy. Three external datasets and the mouse single-cell dataset showed high accuracy of the diagnostic model, in addition to high performance and predictive value of the diagnostic model in DCA and CIC. MR analysis looked at stroke after SAH independent of SAH, but associated with multiple intermediate factors including Hypertensive diseases, Total triglycerides levels in medium HDL and Platelet count. qPCR confirmed that significant differences in DCI signature genes were observed between the SAH and SAH-DCI groups. Finally, valproic acid became a potential therapeutic agent for DCI based on the results of target prediction and molecular docking of the characterized genes.

CONCLUSION

This diagnostic model can identify SAH patients at high risk for DCI and may provide potential mechanisms and therapeutic targets for DCI. Valproic acid may be an important future drug for the treatment of DCI.

Prevalence of unruptured intracranial aneurysms (UIAs) examined in the trauma population

BACKGROUND

Previous data on the prevalence of unruptured intracranial aneurysms (UIAs) vary widely, and studies based on these data are plagued with unintentional bias. Accurate prevalence data are paramount for any physician who counsels patients with intracranial aneurysms on rupture risk and treatment. We therefore sought to determine a more accurate number for the true prevalence of UIAs.

METHODS

A retrospective chart review was conducted at a level 1 trauma center and tertiary care hospital in an urban setting between 2019 and 2020. Inclusion criteria included patients admitted with blunt trauma. Exclusion criteria included not having a head and neck CTA performed and read by an attending radiologist. All head and neck CTA radiology reads were reviewed for incidentally discovered UIAs. Subgroup analysis was performed by age group, race, and gender.

RESULTS

A total of 5978 out of 8999 patients met the inclusion criteria, and 54 patients with 58 total aneurysms were identified giving an overall prevalence of 0.9%. Subgroup analysis was performed for all age groups, genders, and racial groups.

CONCLUSION

The overall aneurysm prevalence was found to be 0.9% in this sample. This rate is lower than rates previously cited in the literature and those quoted in local practice. This finding has significant implications when attempting to understand average rupture risk. Further studies are needed to power more subgroup analyses to use a more personalized approach to understanding an individual's risk of rupture.

Knowledge domain and emerging trends in the rupture risk of intracranial aneurysms research from 2004 to 2023

BACKGROUND

Intracranial aneurysms (IAs) pose significant health risks, attributable to their potential for sudden rupture, which can result in severe outcomes such as stroke and death. Despite extensive research, the variability of aneurysm behavior, with some remaining stable for years while others rupture unexpectedly, remains poorly understood.

AIM

To employ bibliometric analysis to map the research landscape concerning risk factors associated with IAs rupture.

METHODS

A systematic literature review of publications from 2004 to 2023 was conducted, analyzing 3804 documents from the Web of Science Core Collection database, with a focus on full-text articles and reviews in English. The analysis encompassed citation and co-citation networks, keyword bursts, and temporal trends to delineate the evolution of research themes and collaboration patterns. Advanced software tools, CiteSpace and VOSviewer, were utilized for comprehensive data visualization and trend analysis.

RESULTS

Analysis uncovered a total of 3804 publications on IA rupture risk factors between 2006 and 2023. Research interest surged after 2013, peaking in 2023. The United States led with 28.97% of publications, garnering 37706 citations. Notable United States-China collaborations were observed. Capital Medical University produced 184 publications, while Utrecht University boasted a citation average of 69.62 per publication. "World Neurosurgery" published the most papers, contrasting with "Stroke", the most cited journal. The PHASES score from "Lancet Neurology" emerged as a vital rupture risk prediction tool. Early research favored endovascular therapy, transitioning to magnetic resonance imaging and flow diverters. "Subarachnoid hemorrhage" stood out as a recurrent keyword.

CONCLUSION

This study assesses global IA research trends and highlights crucial gaps, guiding future investigations to improve preventive and therapeutic approaches.

Association between blood urea nitrogen-to-potassium ratio and 30-day all-cause mortality in patients with non-traumatic subarachnoid hemorrhage

BACKGROUND

The mortality risk is exceptionally high in non-traumatic subarachnoid hemorrhage (SAH). Elevated blood urea nitrogen (BUN) levels and hypokalemia are prevalent issues in patients with non-traumatic SAH. To explore the correlation between the blood urea nitrogen-to-potassium ratio (BPR) and 30-day all-cause mortality in non-traumatic SAH patients.

METHODS

We systematically extracted specific clinical data from the Medical Information Mart for Intensive IV (MIMIC-IV) database. To assess the prognostic relevance of the BPR, we categorized patients into those experiencing in-hospital mortality within 30 days and those surviving, subjecting them to both univariate and multivariate Cox regression analyses. The optimal BPR cut-off value was identified using Receiver Operating Characteristic (ROC) curve analysis, employing the maximum Youden index to predict survival status. Furthermore, we employed Kaplan-Meier (K-M) analysis to illustrate survival curves.

RESULTS

A cohort comprising 608 patients with non-traumatic SAH was enrolled in the investigation. Multivariate Cox regression analysis identified the BPR as an independent predictor of all-cause mortality within 30 days of admission for patients with non-traumatic SAH (Hazard Ratio [HR], 1.13; 95 % Confidence Interval [CI], 1.04---1.23; P<0.05). Further refinement resulted in the establishment of an optimized prediction model (AUC=83.61 %, 95 % CI: 79.73 % - 87.49 %) for forecasting all-cause mortality at 30 days post-hospital admission in patients with non-traumatic SAH.

CONCLUSION

The BPR emerges as an independent prognostic indicator for all-cause mortality within the initial 30 days of admission among non-traumatic SAH patients.

Primary decompressive craniectomy in patients with large intracerebral hematomas due to aneurysmal subarachnoid hemorrhage

BACKGROUND

Decompressive craniectomy (DC) can alleviate increased intracranial pressure in aneurysmal subarachnoid hemorrhage patients with concomitant space-occupying intracerebral hemorrhage, but also carries a high risk for complications. We studied outcomes and complications of DC at time of ruptured aneurysm repair.

METHODS

Of 47 patients treated between 2010 and 2020, 30 underwent DC during aneurysm repair and hematoma evacuation and 17 did not. We calculated odds ratios (OR) for delayed cerebral ischemia (DCI), angiographic vasospasm, DCI-related infarction, and unfavorable functional outcome (extended Glasgow Outcome Scale 1-5) at three months. Complication rates after DC and cranioplasty in the aneurysmal subarachnoid hemorrhage patients were compared to those of all 107 patients undergoing DC for malignant cerebral infarction during the same period.

RESULTS

In DC versus no DC patients, proportions were for clinical DCI 37% versus 53% (OR = 0.5;95%CI:0.2-1.8), angiographic vasospasm 37% versus 47% (OR = 0.7;95%CI:0.2-2.2), DCI-related infarctions 17% versus 47% (OR = 0.2;95%CI:0.1-0.7) and unfavorable outcome 80% versus 88% (OR = 0.5;95%CI:0.1-3.0). ORs were similar after adjustment for baseline predictors for outcome. Complications related to DC and cranioplasty occurred in 18 (51%) of subarachnoid hemorrhage patients and 41 (38%) of cerebral infarction patients (OR = 1.7;95%CI:0.8-3.7).

CONCLUSIONS

In patients with aneurysmal subarachnoid hemorrhage and concomitant space-occupying intracerebral hemorrhage, early DC was not associated with improved functional outcomes, but with a reduced rate of DCI-related infarctions. This potential benefit has to be weighed against high complication rates of DC in subarachnoid hemorrhage patients.

Deacetylase SIRT2 Inhibition Promotes Microglial M2 Polarization Through Axl/PI3K/AKT to Alleviate White Matter Injury After Subarachnoid Hemorrhage

White matter injury (WMI) subsequent to subarachnoid hemorrhage (SAH) frequently leads to an unfavorable patient prognosis. Previous studies have indicated that microglial M1 polarization following SAH results in the accumulation of amyloid precursor protein (APP) and degradation of myelin basic protein (MBP), thereby catalyzing the exacerbation of WMI. Consequently, transitioning microglial polarization towards the M2 phenotype (neuroprotective state) represents a potential therapeutic approach for reversing WMI. The SIRT2 gene is pivotal in neurological disorders such as neurodegeneration and ischemic stroke. However, its function and underlying mechanisms in SAH, particularly how it influences microglial function to ameliorate WMI, remain unclear. Our investigations revealed that in post-SAH, there was a temporal increase in SIRT2 expression, predominantly in the cerebral corpus callosum area, with notable colocalization with microglia. However, following the administration of the SIRT2 inhibitor AK-7, a shift in microglial polarization towards the M2 phenotype and an improvement in both short-term and long-term neuronal functions in rats were observed. Mechanistically, CO-IP experiments confirmed that SIRT2 can interact with the receptor tyrosine kinase Axl within the TAM receptor family and act as a deacetylase to regulate the deacetylation of Axl. Concurrently, the inhibition of SIRT2 by AK-7 can lead to increased expression of Axl and activation of the anti-inflammatory pathway PI3K/Akt signaling pathway, which regulates microglial M2 polarization and consequently reduces WMI. However, when Axl expression was inhibited by the injection of the shAxl virus into the lateral ventricles, the downstream signaling pathways were significantly suppressed. Rescue experiments also confirmed that the neuroprotective effects of AK-7 can be reversed by PI3K inhibitors. These data suggest that SIRT2 influences WMI by affecting microglial polarization through the Axl/PI3K/AKT pathway, and that AK-7 could serve as an effective therapeutic drug for improving neurological functions in SAH patients.

Identifying novel risk genes in intracranial aneurysm by integrating human proteomes and genetics

Genome-wide association studies (GWAS) have become increasingly popular for detecting numerous loci associated with intracranial aneurysm (IA), but how these loci function remains unclear. In this study, we employed an integrative analytical pipeline to efficiently transform genetic associations and identify novel genes for IA. Using multidimensional high-throughput data, we integrated proteome-wide association studies (PWAS), transcriptome-wide association studies (TWAS), Mendelian randomization (MR) and Bayesian co-localization analyses to prioritize genes that can increase IA risk by altering their expression and protein abundances in the brain and blood. Moreover, single-cell RNA sequencing (scRNA-seq) of the circle of Willis was performed to enrich filtered genes in cells, and gene set enrichment analysis (GSEA) was conducted for each gene using bulk RNA-seq data for IA. No significant genes with cis-regulated plasma protein levels were proven to be associated with IA. The protein abundances of five genes in the brain were found to be associated with IA. According to cellular enrichment analysis, these five genes were expressed mainly in the endothelium, fibroblasts and vascular smooth muscle cells. Only three genes, CNNM2, GPRIN3 and UFL1, passed MR and Bayesian co-localization analyses. While UFL1 was not validated in confirmation PWAS as it was not profiled, it was validated in TWAS. GSEA suggested these three genes are associated with the cell cycle. In addition, the protein abundance of CNNM2 was found to be associated with IA rupture (based on PWAS, MR and co-localization analyses). Our findings indicated that CNNM2, GPRIN3 and UFL1 (CNNM2 correlated with IA rupture) are potential IA risk genes that may provide a broad hint for future research on possible mechanisms and therapeutic targets for IA.

Causal association between circulating inflammatory cytokines and intracranial aneurysm and subarachnoid hemorrhage

BACKGROUND AND PURPOSE

The causal association between inflammatory cytokines and the development of intracranial aneurysm (IA), unruptured IA (uIA) and subarachnoid hemorrhage (SAH) lacks clarity.

METHODS

The summary-level datasets for inflammatory cytokines were extracted from a genome-wide association study of the Finnish Cardiovascular Risk in Young Adults Study and the FINRISK survey. The summary statistics datasets related to IA, uIA and SAH were obtained from the genome-wide association study meta-analysis of the International Stroke Genetics Consortium and FinnGen Consortium. The primary method employed for analysis was inverse variance weighting (false discovery rate), supplemented by sensitivity analyses to address pleiotropy and enhance robustness.

RESULTS

In the International Stroke Genetics Consortium, 10, six and eight inflammatory cytokines exhibited a causal association with IA, uIA and SAH, respectively (false discovery rate, p < 0.05). In FinnGen datasets, macrophage Inflammatory Protein-1 Alpha (MIP_1A), MIP_1A and interferon γ-induced protein 10 (IP_10) were verified for IA, uIA and SAH, respectively. In the reverse Mendelian randomization analysis, the common cytokines altered by uIA and SAH were vascular endothelial growth factor (VEGF), MIP_1A, IL_9, IL_10 and IL_17, respectively. The meta-analysis results show that MIP_1A and IP_10 could be associated with the decreased risk of IA, and MIP_1A and IP_10 were associated with the decreased risk of uIA and SAH, respectively. Notably, the levels of VEGF, MIP_1A, IL_9, IL_10 and TNF_A were increased with uIA. Comprehensive heterogeneity and pleiotropy analyses confirmed the robustness of these results.

CONCLUSION

Our study unveils a bidirectional association between inflammatory cytokines and IA, uIA and SAH. Further investigations are essential to validate their relationship and elucidate the underlying mechanisms.

Systemic tolerance of intravenous milrinone administration for cerebral vasospasm secondary to non-traumatic subarachnoid hemorrhage

PURPOSE

Delayed cerebral ischemia (DCI) is a severe subarachnoid hemorrhage (SAH) complication, closely related to cerebral vasospasm (CVS). CVS treatment frequently comprises intravenous milrinone, an inotropic and vasodilatory drug. Our objective is to describe milrinone's hemodynamic, respiratory and renal effects when administrated as treatment for CVS.

METHODS

Retrospective single-center observational study of patients receiving intravenous milrinone for CVS with systemic hemodynamics, oxygenation, renal disorders monitoring. We described these parameters' evolution before and after milrinone initiation (day - 1, baseline, day 1 and day 2), studied treatment cessation causes and assessed neurological outcome at 3-6 months.

RESULTS

Ninety-one patients were included. Milrinone initiation led to cardiac output increase (4.5 L/min [3.4-5.2] at baseline vs 6.6 L/min [5.2-7.7] at day 2, p < 0.001), Mean Arterial Pressure decrease (101 mmHg [94-110] at baseline vs 95 mmHg [85-102] at day 2, p = 0.001) norepinephrine treatment requirement increase (32% of patients before milrinone start vs 58% at day 1, p = 0.002) and slight PaO2/FiO2 ratio deterioration (401 [333-406] at baseline vs 348 [307-357] at day 2, p = 0.016). Milrinone was interrupted in 8% of patients. 55% had a favorable outcome.

CONCLUSION

Intravenous milrinone for CVS treatment seems associated with significant impact on systemic hemodynamics leading sometimes to treatment discontinuation.

Three-dimensional wall-thickness distributions of unruptured intracranial aneurysms characterized by micro-computed tomography

Aneurysmal rupture is associated with wall thinning, but the mechanism is poorly understood. This study aimed to characterize the three-dimensional wall-thickness distributions of unruptured intracranial aneurysms. Five aneurysmal tissues were investigated using micro-computed tomography. First, the wall thickness was related to the aneurysmal wall appearances during surgery. The median wall thicknesses of the translucent and non-translucent walls were 50.56 and 155.93 µm, respectively (p < 0.05) with significant variation in the non-translucent wall thicknesses (p < 0.05). The three-dimensional observations characterized the spatial variation of wall thicknesses. Thin walls showed a uniform thickness profile ranging from 10 to 40 µm, whereas thick walls presented a peaked thickness profile ranging from 300 to 500 µm. In transition walls, the profile undulated due to the formation of focal thin/thick spots. Overall, the aneurysmal wall thicknesses were strongly site-dependent and spatially varied by 10 to 40 times within individual cases. Aneurysmal walls are exposed to wall stress driven by blood pressure. In theory, the magnitude of wall stress is inversely proportional to wall thickness. Thus, the observed spatial variation of wall thickness may increase the spatial variation of wall stress to a similar extent. The irregular wall thickness may yield stress concentration. The observed thin walls and focal thin spots may be caused by excessive wall stresses at the range of mechanical failure inducing wall injuries, such as microscopic tears, during aneurysmal enlargement. The present results suggested that blood pressure (wall stress) may have a potential of acting as a trigger of aneurysmal wall injury.

Circ_0008571 modulates the phenotype of vascular smooth muscle cells by targeting miR-145-5p in intracranial aneurysms

BACKGROUND

The dysfunction of human vascular smooth cells (hVSMCs) is significantly connected to the development of intracranial aneurysms (IAs). By suppressing the activity of microRNAs (miRNAs), circular RNAs (circRNAs) participate in IA pathogenesis. Nevertheless, the role of hsa_circ_0008571 in IAs remains unclear.

METHODS

circRNA sequencing was used to identify circRNAs from human IA tissues. To determine the function of circ_0008571, Transwell, wound healing, and cell proliferation assays were conducted. To identify the target of circ_0008571, the analyses of CircInteractome and TargetScan, as well as the luciferase assay were carried out. Furthermore, circ_0008571 knockdown and over-expression were performed to investigate its functions in IA development and the underlying molecular mechanisms.

RESULTS

Both hsa_circ_0008571 and Integrin beta 8 (ITGB8) were downregulated, while miR-145-5p transcription was elevated in the aneurysm wall of IAs patients compared to superficial temporal artery tissues. In vitro, cell migration and growth were dramatically suppressed after hsa_circ_0008571 overexpression. Mechanistically, has_circ_0008571 could suppress miR-145-5p activity by direct sponging. Moreover, we found that ITGB8 expression and the activation of the TGF-β-mediated signaling pathway were significantly enhanced.

CONCLUSION

The hsa_circ_0008571-miR-145-5p-ITGB8 axis plays an essential role in IA progression.

Causal Effect Estimation on Imaging and Clinical Data for Treatment Decision Support of Aneurysmal Subarachnoid Hemorrhage

Aneurysmal subarachnoid hemorrhage is a medical emergency of brain that has high mortality and poor prognosis. Causal effect estimation of treatment strategies on patient outcomes is crucial for aneurysmal subarachnoid hemorrhage treatment decision-making. However, most existing studies on treatment decision-making support of this disease are unable to simultaneously compare the potential outcomes of different treatments for a patient. Furthermore, these studies fail to harmoniously integrate the imaging data with non-imaging clinical data, both of which are useful in clinical scenarios. In this paper, we estimate the causal effect of various treatments on patients with aneurysmal subarachnoid hemorrhage by integrating plain CT with non-imaging clinical data, which is represented using structured tabular data. Specifically, we first propose a novel scheme that uses multi-modality confounders distillation architecture to predict the treatment outcome and treatment assignment simultaneously. With these distilled confounder features, we design an imaging and non-imaging interaction representation learning strategy to use the complementary information extracted from different modalities to balance the feature distribution of different treatment groups. We have conducted extensive experiments using a clinical dataset of 656 subarachnoid hemorrhage cases, which was collected from the Hospital Authority Data Collaboration Laboratory in Hong Kong. Our method shows consistent improvements on the evaluation metrics of treatment effect estimation, achieving state-of-the-art results over strong competitors. Code is released at https://github.com/med-air/TOP-aSAH.

Gender-specific prognosis models reveal differences in subarachnoid hemorrhage patients between sexes

BACKGROUND

Subarachnoid hemorrhage (SAH) represents a severe stroke subtype. Our study aims to develop gender-specific prognostic prediction models derived from distinct prognostic factors observed among different-gender patients.

METHODS

Inclusion comprised SAH-diagnosed patients from January 2014 to March 2016 in our institution. Collected data encompassed patients' demographics, admission severity, treatments, imaging findings, and complications. Three-month post-discharge prognoses were obtained via follow-ups. Analyses assessed gender-based differences in patient information. Key factors underwent subgroup analysis, followed by univariate and multivariate analyses to identify gender-specific prognostic factors and establish/validate gender-specific prognostic models.

RESULTS

A total of 929 patients, with a median age of 57 (16) years, were analyzed; 372 (40%) were male, and 557 (60%) were female. Differences in age, smoking history, hypertension, aneurysm presence, and treatment interventions existed between genders (p < 0.01), yet no disparity in prognosis was noted. Subgroup analysis explored hypertension history, aneurysm presence, and treatment impact, revealing gender-specific variations in these factors' influence on the disease. Screening identified independent prognostic factors: age, SEBES score, admission GCS score, and complications for males; and age, admission GCS score, intraventricular hemorrhage, treatment interventions, symptomatic vasospasm, hydrocephalus, delayed cerebral ischemia, and seizures for females. Evaluation and validation of gender-specific models yielded an AUC of 0.916 (95% CI: 0.878-0.954) for males and 0.914 (95% CI: 0.885-0.944) for females in the ROC curve. Gender-specific prognostic models didn't significantly differ from the overall population-based model (model 3) but exhibited robust discriminative ability and clinical utility.

CONCLUSION

Variations in baseline and treatment-related factors among genders contribute partly to gender-based prognosis differences. Independent prognostic factors vary by gender. Gender-specific prognostic models exhibit favorable prognostic performance.

Genetically Predicted Vascular Proteins and Risk of Intracranial Aneurysms: A Mendelian Randomization Study

The relationship between vascular proteins (VPs) and intracranial aneurysms (IAs) has not been fully elucidated. We used Mendelian randomization (MR) analysis to explore the effect of VPs on IAs. Dataset of aneurysmal subarachnoid hemorrhage (aSAH) [5140 cases and 71,934 controls] and unruptured intracranial aneurysm (uIA) [2070 cases and 71,934 controls] were obtained from individuals of European ancestry. Univariate MR was used to explore the associations between 90 VPs and IAs. Then, we performed multivariate MR (MVMR) to further investigate the identified VP-to-IA estimates. Two-sample MR showed that TNFSF14 was inversely associated with aSAH (odds ratio [OR] = 0.831, 95% CI: 0.713-0.969, p = 0.018). IL-16 (OR = 1.218, 95% CI: 1.032-1.438, p = 0.020) and AgRP (OR = 1.394, 95% CI: 1.048-1.855, p = 0.023) were positively associated with aSAH. HBEGF (OR = 0.642, 95% CI: 0.461-0.894, p = 0.009), MCP-1 (OR = 1.537, 95% CI: 1.007-2.344, p = 0.046), and CX3CL1 (OR = 0.762, 95% CI: 0.581-0.999, 0.049 < p < 0.050) were associated with uIA risk. The MVMR showed that the TNFSF14-to-aSAH estimate remained statistically significant after adjustment for past tobacco smoking, alcohol consumption, systolic blood pressure and body mass index. Our study indicated that low serum TNFSF14 levels might be a potential risk factor for IA rupture. Five VPs (HBEGF, MCP-1, IL-6, CX3CL1, and AgRP) are associated with the risk of IAs (both uIA and aSAH).

Analyzing the relationship between cerebral aneurysms and Non-oculomotor cranial nerve palsies: a systematic review

OBJECTIVES

This study aimed to investigate the association between intracerebral aneurysms and cranial nerve (CN) palsies, focusing on nerves other than the oculomotor nerve. It sought to determine the prevalence, risk factors, and clinical outcomes of these nerve palsies and compare the effectiveness of microsurgical clipping versus endovascular coiling in restoring nerve function.

METHODOLOGY

Following PRISMA guidelines, a comprehensive literature search was conducted using databases like PubMed, Scopus, and Google Scholar, covering studies from 1975 to April 2024. The inclusion criteria targeted patients with non-oculomotor nerve palsies diagnosed with cerebral aneurysms. Studies published before 1975 and non-English studies were excluded. Data extraction included study design, patient characteristics, and intervention outcomes. The Joanna Briggs Institute and Newcastle-Ottawa scales were used to assess study quality. Data were synthesized narratively and statistically analysed using SPSS v27.

RESULTS

The analysis included 47 patients (53.2% female, mean age 44.8 years). The internal carotid artery (ICA) was the most common aneurysm site (44.7%), and the abducent nerve (CN VI) was most frequently affected. Ruptured aneurysms had better recovery outcomes (88.9%) than unruptured ones (66.7%). Hypertension was present in 9.2%. Unilateral aneurysms were seen in 80.9%, with 76.6% having a single nerve palsy. Non-ruptured aneurysms accounted for 58.1%, and ruptured for 41.9% of associated cranial nerve palsies. Treatment included microsurgical approaches (42.6%), endovascular approaches (34%), combined approaches (6.4%), and conservative management (17%). Recovery of the palsy was observed in 75.6%, with endovascular procedures showing higher recovery (93.3%) compared to conservative treatment (28.6%).

CONCLUSION

Intracerebral aneurysms are significantly associated with non-oculomotor CN palsies. Endovascular procedures yield higher recovery rates than conservative management, particularly in ruptured aneurysms. Timely and appropriate treatment is crucial for improving nerve function recovery in these patients.

Flow Diversion for Endovascular Treatment of Intracranial Aneurysms: Past, Present, and Future Directions

Flow diversion for intracranial aneurysms emerged as an efficacious and durable treatment option over the last two decades. In a paradigm shift from intrasaccular aneurysm embolization to parent vessel remodeling as the mechanism of action, the proliferation of flow-diverting devices has enabled the treatment of many aneurysms previously considered untreatable. In this review, we review the history and development of flow diverters, highlight the pivotal clinical trials leading to their regulatory approval, review current devices including endoluminal and intrasaccular flow diverters, and discuss current and expanding indications for their use. Areas of clinical equipoise, including ruptured aneurysms and wide-neck bifurcation aneurysms, are summarized with a focus on flow diverters for these pathologies. Finally, we discuss future directions in flow diversion technology including bioresorbable flow diverters, transcriptomics and radiogenomics, and machine learning and artificial intelligence.

Comparison of long-term clinical outcome after endovascular versus neurosurgical treatment of ruptured intracranial anterior circulation aneurysms: A single-centre experience

Introduction

In patients with anterior circulation aneurysmal Subarachnoid Haemorrhage (aSAH), endovascular coiling is currently practiced more frequently than neurosurgical clipping. However, despite multiple previous studies, it is still uncertain whether coiling is favourable in terms of long-term clinical outcome.

Research question

What is the effect of clipping versus coiling on long-term functional outcome of patients with an aSAH?

Material and methods

All anterior circulation aSAH patients (2012-2015) treated with clipping or coiling in two hospitals in the Netherlands were studied up to five years after treatment. Functional outcome, survival, retreatment- and complication rate were measured. Survival analysis was performed in both groups. A multivariable regression model with covariate adjustment was performed to investigate the likelihood of unfavourable outcome (modified Rankin Scale >2).

Results

Out of 204 patients, 75 patients were clipped (37%) and 129 received coiling (63%). Coiling had a higher retreatment rate compared to clipping (7.8% vs. 0.0%). Unfavourable outcome at six, 12, 24 and 60 months after treatment was higher for patients after clipping compared to coiling, but was not significant after correcting for clinical severity as represented by the WFNS grade. In 60 months, no difference in survival was found between clipping and coiling.

Discussion and conclusion

No differences between clipping and coiling in survival and long-term functional outcome have been found in this study. More research with prospective design and large cohorts is needed to identify possible differences between the two treatments.

What to Measure in Aneurysmal Subarachnoid Haemorrhage Research-An International Delphi Survey

Aneurysmal subarachnoid haemorrhage (aSAH) is a devastating condition with high mortality and morbidity. The outcome measures used in aSAH clinical research vary making it challenging to compare and combine different studies. Additionally, there may be a mismatch between the outcomes prioritized by patients, caregivers, and health care providers and those selected by researchers. We conducted an international, online, multiple round Delphi study to develop consensus on domains (where a domain is a health concept or aspect) prioritized by key stakeholders including those with lived experience of aSAH, health care providers, and researchers, funders, or industry professionals. One hundred seventy-five people participated in the survey, 59% of whom had lived experience of aSAH. Over three rounds, 32 domains reached the consensus threshold pre-defined as 70% of participants rating the domain as being critically important. During the fourth round, participants ranked the importance of each of these 32 domains. The top ten domains ranked highest to lowest were (1) Cognition and executive function, (2) Aneurysm obliteration, (3) Cerebral infarction, (4) Functional outcomes including ability to walk, (5) Delayed cerebral ischemia, (6) The overall quality of life as reported by the SAH survivor, (7) Changes to emotions or mood (including depression), (8) The basic activities of daily living, (9) Vasospasm, and (10) ICU complications. Our findings confirm that there is a mismatch between domains prioritized by stakeholders and outcomes used in clinical research. Our future work aims to address this mismatch through the development of a core outcome set in aSAH research.

Relationship between stress hyperglycemia ratio and prognosis in patients with aneurysmal subarachnoid hemorrhage: a two-center retrospective study

Previous research have demonstrated that the stress hyperglycemia ratio (SHR) accurately reflects acute hyperglycemic states and correlates with adverse outcomes. This study aims to explore the relationship between SHR and the prognosis of patients with aneurysmal subarachnoid hemorrhage (aSAH). Patients with aSAH were categorized into four groups based on SHR tertiles. Functional outcomes were evaluated at 12 months using the modified Rankin Scale (mRS), with scores ranging from 0 to 2 indicating a good outcome and 3-6 indicating a poor outcome. The associations between SHR and functional outcomes were analyzed using logistic regression models and restricted cubic spline analysis. A total of 127 patients exhibited poor functional outcomes. Following comprehensive adjustments, those in the highest SHR tertile had a significantly increased risk of poor prognosis compared to those in the lowest tertile (odds ratio [OR], 4.12; 95% confidence interval [CI]: 1.87-9.06). Moreover, each unit increase in SHR was associated with a 7.51-fold increase in the risk of poor prognosis (OR, 7.51; 95% CI: 3.19-17.70). Further analysis using restricted cubic spline confirmed a linear correlation between SHR and poor prognosis (P for nonlinearity = 0.609). Similar patterns were observed across all studied subgroups. Elevated SHR significantly correlates with poor functional prognosis at one year in patients with aSAH, independent of their diabetes status.

Partial coil embolization before surgical clipping of ruptured intracranial aneurysms

OBJECTIVE

Intraoperative rupture (IOR) is the most common adverse event encountered during surgical clip obliteration of ruptured intracranial aneurysms. Besides increasing surgeon experience and early proximal control, no methods exist to decrease IOR risk. Thus, our objective was to assess if partial endovascular coil embolization to protect the aneurysm before clipping decreases IOR.

METHODS

We conducted a retrospective analysis of patients with ruptured intracranial aneurysms that were treated with surgical clipping at two tertiary academic centers. We compared patient characteristics and outcomes of those who underwent partial endovascular coil embolization to protect the aneurysm before clipping to those who did not. The primary outcome was IOR. Secondary outcomes were inpatient mortality and discharge destination.

RESULTS

We analyzed 100 patients. Partial endovascular aneurysm protection was performed in 27 patients. Age, sex, subarachnoid hemorrhage severity, and aneurysm location were similar between the partially-embolized and non-embolized groups. The median size of the partially-embolized aneurysms was larger (7.0 mm [interquartile range 5.95-8.7] vs. 4.6 mm [3.3-6.0]; P < 0.001). During surgical clipping, IOR occurred less frequently in the partially-embolized aneurysms than non-embolized aneurysms (2/27, 7.4%, vs. 30/73, 41%; P = 0.001). Inpatient mortality was 14.8% (4/27) in patients with partially-embolized aneurysms and 28.8% (21/73) in patients without embolization (P = 0.20). Discharge to home or inpatient rehabilitation was 74.0% in patients with partially-embolized aneurysms and 56.2% in patients without embolization (P = 0.11). A complication from partial embolization occurred in 2/27 (7.4%) patients.

CONCLUSIONS

Preoperative partial endovascular coil embolization of ruptured aneurysms is associated with a reduced frequency of IOR during definitive treatment with surgical clip obliteration. These results and the impact of preoperative partial endovascular coil embolization on functional outcomes should be confirmed with a randomized trial.

CTP for the Screening of Vasospasm and Delayed Cerebral Ischemia in Aneurysmal SAH: A Systematic Review and Meta-analysis

BACKGROUND

Delayed cerebral ischemia and vasospasm are the most common causes of late morbidity following aneurysmal SAH, but their diagnosis remains challenging.

PURPOSE

This systematic review and meta-analysis investigated the diagnostic performance of CTP for detection of delayed cerebral ischemia and vasospasm in the setting of aneurysmal SAH.

DATA SOURCES

Studies evaluating the diagnostic performance of CTP in the setting of aneurysmal SAH were searched on the Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, Cochrane Clinical Answers, Cochrane Methodology Register, Ovid MEDLINE, EMBASE, American College of Physicians Journal Club, Database of Abstracts of Reviews of Effects, Health Technology Assessment, National Health Service Economic Evaluation Database, PubMed, and Google Scholar from their inception to September 2023.

STUDY SELECTION

Thirty studies were included, encompassing 1786 patients with aneurysmal SAH and 2302 CTP studies. Studies were included if they compared the diagnostic accuracy of CTP with a reference standard (clinical or radiologic delayed cerebral ischemia, angiographic spasm) for the detection of delayed cerebral ischemia or vasospasm in patients with aneurysmal SAH. The primary outcome was accuracy for the detection of delayed cerebral ischemia or vasospasm.

DATA ANALYSIS

Bivariate random effects models were used to pool outcomes for sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio. Subgroup analyses for individual CTP parameters and early-versus-late study timing were performed. Bias and applicability were assessed using the modified QUADAS-2 tool.

DATA SYNTHESIS

For assessment of delayed cerebral ischemia, CTP demonstrated a pooled sensitivity of 82.1% (95% CI, 74.5%-87.8%), specificity of 79.6% (95% CI, 73.0%-84.9%), positive likelihood ratio of 4.01 (95% CI, 2.94-5.47), and negative likelihood ratio of 0.23 (95% CI, 0.12-0.33). For assessment of vasospasm, CTP showed a pooled sensitivity of 85.6% (95% CI, 74.2%-92.5%), specificity of 87.9% (95% CI, 79.2%-93.3%), positive likelihood ratio of 7.10 (95% CI, 3.87-13.04), and negative likelihood ratio of 0.16 (95% CI, 0.09-0.31).

LIMITATIONS

QUADAS-2 assessment identified 12 articles with low risk, 11 with moderate risk, and 7 with a high risk of bias.

CONCLUSIONS

For delayed cerebral ischemia, CTP had a sensitivity of >80%, specificity of >75%, and a low negative likelihood ratio of 0.23. CTP had better performance for the detection of vasospasm, with sensitivity and specificity of >85% and a low negative likelihood ratio of 0.16. Although the accuracy offers the potential for CTP to be used in limited clinical contexts, standardization of CTP techniques and high-quality randomized trials evaluating its impact are required.

Vitamin D deficiency promotes intracranial aneurysm rupture

Intracranial aneurysm rupture causes severe disability and high mortality. Epidemiological studies show a strong association between decreased vitamin D levels and an increase in aneurysm rupture. However, the causality and mechanism remain largely unknown. In this study, we tested whether vitamin D deficiency promotes aneurysm rupture and examined the underlying mechanism for the protective role of vitamin D against the development of aneurysm rupture utilizing a mouse model of intracranial aneurysm. Mice consuming a vitamin D-deficient diet had a higher rupture rate than mice with a regular diet. Vitamin D deficiency increased proinflammatory cytokines in the cerebral arteries. Concurrently, vitamin D receptor knockout mice had a higher rupture rate than the corresponding wild-type littermates. The vitamin D receptors on endothelial and vascular smooth muscle cells, but not on hematopoietic cells, mediated the effect of aneurysm rupture. Our results establish that vitamin D protects against the development of aneurysmal rupture through the vitamin D receptors on vascular endothelial and smooth muscle cells. Vitamin D supplementation may be a viable pharmacologic therapy for preventing aneurysm rupture.

Integrating PointNet-Based Model and Machine Learning Algorithms for Classification of Rupture Status of IAs

BACKGROUND

The rupture of intracranial aneurysms (IAs) would result in subarachnoid hemorrhage with high mortality and disability. Predicting the risk of IAs rupture remains a challenge.

METHODS

This paper proposed an effective method for classifying IAs rupture status by integrating a PointNet-based model and machine learning algorithms. First, medical image segmentation and reconstruction algorithms were applied to 3D Digital Subtraction Angiography (DSA) imaging data to construct three-dimensional IAs geometric models. Geometrical parameters of IAs were then acquired using Geomagic, followed by the computation of hemodynamic clouds and hemodynamic parameters using Computational Fluid Dynamics (CFD). A PointNet-based model was developed to extract different dimensional hemodynamic cloud features. Finally, five types of machine learning algorithms were applied on geometrical parameters, hemodynamic parameters, and hemodynamic cloud features to classify and recognize IAs rupture status. The classification performance of different dimensional hemodynamic cloud features was also compared.

RESULTS

The 16-, 32-, 64-, and 1024-dimensional hemodynamic cloud features were extracted with the PointNet-based model, respectively, and the four types of cloud features in combination with the geometrical parameters and hemodynamic parameters were respectively applied to classify the rupture status of IAs. The best classification outcomes were achieved in the case of 16-dimensional hemodynamic cloud features, the accuracy of XGBoost, CatBoost, SVM, LightGBM, and LR algorithms was 0.887, 0.857, 0.854, 0.857, and 0.908, respectively, and the AUCs were 0.917, 0.934, 0.946, 0.920, and 0.944. In contrast, when only utilizing geometrical parameters and hemodynamic parameters, the accuracies were 0.836, 0.816, 0.826, 0.832, and 0.885, respectively, with AUC values of 0.908, 0.922, 0.930, 0.884, and 0.921.

CONCLUSION

In this paper, classification models for IAs rupture status were constructed by integrating a PointNet-based model and machine learning algorithms. Experiments demonstrated that hemodynamic cloud features had a certain contribution weight to the classification of IAs rupture status. When 16-dimensional hemodynamic cloud features were added to the morphological and hemodynamic features, the models achieved the highest classification accuracies and AUCs. Our models and algorithms would provide valuable insights for the clinical diagnosis and treatment of IAs.

A Mendelian randomisation, propensity score matching study to investigate causal association between serum homocysteine and intracranial aneurysm

BACKGROUND AND PURPOSE

Recent observational studies have reported that serum total homocysteine (tHcy) is associated with intracranial aneurysms (IAs). However, the causal effect of tHcy on IAs is unknown. We leveraged large-scale genetic association and real-world data to investigate the causal effect of tHcy on IA formation.

METHODS

We performed a two-sample Mendelian randomisation (MR) using publicly available genome-wide association studies summary statistics to investigate the causal relationship between tHcy and IAs, following the recommendations of the Strengthening the Reporting of Observational Studies in Epidemiology-MR statement. Furthermore, a propensity score matching (PSM) analysis was conducted to evaluate the detailed effects of tHcy on risk of IA formation by utilizing real-world multicentre data, including 9902 patients with and without IAs (1:1 matched). Further interaction and subgroup analyses were performed to elucidate how tHcy affects risk of IA formation.

RESULTS

MR analyses indicated that genetically determined tHcy was causally associated with IA risk (OR, 1.38, 95% CI 1.07 to 1.79; p=0.018). This is consistent with the more conservative weighted median analysis (OR, 1.41, 95% CI 1.03 to 1.93; p=0.039). Further sensitivity analyses showed no evidence of horizontal pleiotropy or heterogeneity of single nucleotide polymorphisms in causal inference. According to the PSM study, we found that, compared with low tHcy (≤15 µmol/L), moderate tHcy (>15-30 µmol/L) (OR 2.13, 95% CI 1.93 to 2.36) and high tHcy (>30 µmol/L) (OR 3.66, 95% CI 2.71 to 4.95) were associated with a higher IA risk (p trend <0.001). Subgroup analyses demonstrated significant ORs of tHcy in each subgroup when stratified by traditional cardiovascular risk factors. Furthermore, there was also a synergistic effect of tHcy and hypertension on IA risk (p interaction <0.001; the relative excess risk due to interaction=1.65, 95% CI 1.29 to 2.01).

CONCLUSION

Both large-scale genetic evidence and multicentre real-world data support a causal association between tHcy and risk of IA formation. Serum tHcy may serve as a biomarker to identify high-risk individuals who would particularly benefit from folate supplementation.

A prognostic model incorporating the albumin-corrected anion gap in patients with aneurysmal subarachnoid hemorrhage

Background

Aneurysmal subarachnoid hemorrhage (aSAH) patients typically have poor prognoses. The anion gap (AG) has been proven to correlate with mortality in various critically ill patients. However, hypoalbuminemia can lead to underestimations of the true anion gap levels. This study was conducted to verify the prognostic value of single AG and albumin-corrected anion gap (ACAG) among aSAH patients.

Methods

Significant factors in the univariate logistic regression analysis were included in the multivariate logistic regression analysis to explore the risk factors for mortality in aSAH patients and to confirm the independent relationship between ACAG and mortality. The restricted cubic spline (RCS) was used to visually show the relationship between ACAG level and mortality risk of aSAH patients. The predictive model for mortality was developed by incorporating significant factors into the multivariate logistic regression analysis. The prognostic value of ACAG and the developed model was evaluated by calculating the area under the receiver operating characteristics curve (AUC).

Results

Among 710 aSAH patients, a 30-day mortality was observed in 20.3% of the cases. A positive relationship was demonstrated between the ACAG level and mortality in aSAH patients using the RCS curve. The multivariate logistic regression analysis helped discover that only six factors were finally and independently related to mortality of aSAH patients after adjusting for confounding effects, including the Hunt-Hess scale score (p = 0.006), surgical options (p < 0.001), white blood cell count (p < 0.001), serum chloride levels (p = 0.023), ACAG (p = 0.039), and delayed cerebral ischemia (p < 0.001). The AUC values for the AG, albumin, and ACAG in predicting mortality among aSAH patients were 0.606, 0.536, and 0.617, respectively. A logistic regression model, which includes the Hunt-Hess scale score, surgical options, white blood cell count, serum chloride levels, ACAG, and delayed cerebral ischemia, achieved an AUC of 0.911 for predicting mortality.

Conclusion

The ACAG is an effective prognostic marker for aSAH patients. A prognostic model incorporating ACAG could help clinicians evaluate the risk of poor outcomes among aSAH patients, thereby facilitating the development of personalized therapeutic strategies.

Verification of a simplified aneurysm dimensionless flow parameter to predict intracranial aneurysm rupture status

OBJECTIVES

Aneurysm number (An) is a novel prediction tool utilizing parameters of pulsatility index (PI) and aneurysm geometry. An has been shown to have the potential to differentiate intracranial aneurysm (IA) rupture status. The objective of this study is to investigate the feasibility and accuracy of An for IA rupture status prediction using Australian based clinical data.

METHODS

A retrospective study was conducted across three tertiary referral hospitals between November 2017 and November 2020 and all saccular IAs with known rupture status were included. Two sets of An values were calculated based on two sets of PI values previously reported in the literature.

RESULTS

Five hundred and four IA cases were included in this study. The results demonstrated no significant difference between ruptured and unruptured status when using An ≥1 as the discriminator. Further analysis showed no strong correlation between An and IA subtypes. The area under the curve (AUC) indicated poor performance in predicting rupture status (AUC1 = 0.55 and AUC2 = 0.56).

CONCLUSIONS

This study does not support An ≥1 as a reliable parameter to predict the rupture status of IAs based on a retrospective cohort. Although the concept of An is supported by hemodynamic aneurysm theory, further research is needed before it can be applied in the clinical setting.

ADVANCES IN KNOWLEDGE

This study demonstrates that the novel prediction tool, An, proposed in 2020 is not reliable and that further research of this hemodynamic model is needed before it can be incorporated into the prediction of IA rupture status.

Single-Cell Transcriptomics Revealed White Matter Repair Following Subarachnoid Hemorrhage

Existing research indicates the potential for white matter injury repair during the subacute phase following subarachnoid hemorrhage (SAH). However, elucidating the role of brain cell subpopulations in the acute and subacute phases of SAH pathogenesis remains challenging due to the cellular heterogeneity of the central nervous system. In this study, single-cell RNA sequencing was conducted on SAH model mice to delineate distinct cell populations. Gene Set Enrichment Analysis was performed to identify involved pathways, and cellular interactions were explored using the CellChat package in R software. Validation of the findings involved a comprehensive approach, including magnetic resonance imaging, immunofluorescence double staining, and Western blot analyses. This study identified ten major brain clusters with cell type-specific gene expression patterns. Notably, we observed infiltration and clonal expansion of reparative microglia in white matter-enriched regions during the subacute stage after SAH. Additionally, microglia-associated pleiotrophin (PTN) was identified as having a role in mediating the regulation of oligodendrocyte precursor cells (OPCs) in SAH model mice, implicating the activation of the mTOR signaling pathway. These findings emphasize the vital role of microglia-OPC interactions might occur via the PTN pathway, potentially contributing to white matter repair during the subacute phase after SAH. Our analysis revealed precise transcriptional changes in the acute and subacute phases after SAH, offering insights into the mechanism of SAH and for the development of drugs that target-specific cell subtypes.

Blood Pressure Management in Early Aneurysmal Subarachnoid Hemorrhage: A National Cross-Sectional Survey of Canadian Intensivists and Cerebrovascular Neurosurgeons

BACKGROUND

In aneurysmal subarachnoid hemorrhage (aSAH), rebleeding of the culprit aneurysm is associated with significant morbidity and mortality. Blood pressure reduction to specific target levels, with the goal of preventing rebleeding, has been a mainstay of care prior to definitively securing the aneurysm. Clinical practice guidelines have recently changed and no longer recommend specific blood pressure targets. This survey aims to identify the reported practice patterns and beliefs regarding blood pressure management during the early phase of aSAH.

METHODS

We conducted a self-administered, Web-based survey of critical care physicians and cerebrovascular neurosurgeons practicing in Canada. The questionnaire contained 21 items, including 3 case-based scenarios to elicit blood pressure target selection, both before and after aneurysm securing.

RESULTS

In the presecured period, systolic blood pressures of 160 mm Hg (50% [144 of 287]) and 140 mm Hg (42% [120 of 287]) were the most frequently selected upper-limit targets. In the postsecured period, a systolic blood pressure of 180 mm Hg (32% [93 of 287]) was the most frequently selected upper-limit target, but there was a wide distribution of targets selected across all three cases ranging from 100 to > 200 mm Hg. A mean arterial pressure of 65 mm Hg was the most common lower-limit target in both the presecured and postsecured periods. There was little change in blood pressure targets with increasing clinical severity. Predictors of higher or lower blood pressure target selection and barriers to implementation of the desired target were identified.

CONCLUSIONS

During the presecured period, nearly half of the reported upper-limit blood pressure targets are lower than previous guideline recommendations. These targets remain consistent despite increasing clinical severity and could potentially exacerbate cerebral ischemia and negatively impact clinical outcomes. In the postsecured period, there is wide variation in the reported blood pressure targets. A clinical trial is urgently needed to guide decision-making.

Plasma Neurofilament Light Chain as a Biomarker for Poor Outcome After Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

Neurofilament light chain (NfL), a biomarker reflecting neuro-axonal damage, may be useful in improving clinical outcome prediction after aneurysmal subarachnoid hemorrhage (aSAH). We explore the robust and additional value of NfL to neurologic and radiologic grading scales in predicting poor outcome after aSAH.

METHODS

In this prospective cohort study conducted in a single tertiary center, blood samples were collected of aSAH patients within 24 hours after ictus and before endovascular/surgical intervention. The primary endpoint was poor outcome at 6 months' follow-up. Receiver operating curves (ROC), area under the curve (AUC, 95% CI) and model-fit (Nagelkerke R2) were calculated for NfL, neurologic grading scale (WFNS), modified Fisher, age ,and sex. A combined ROC and AUC were calculated for variables with an AUC ≥ 0.70.

RESULTS

A total of 66 (42%) had poor outcome. The AUC of NfL for poor outcome was 0.70 (0.62-0.78). Combining NfL and WFNS resulted in a slightly higher model fit and not-significantly higher AUC for predicting poor outcome (R2 0.51; AUC 0.86, 0.80-0.92) compared with WFNS alone. When patients were stratified according to hemorrhage severity, median NfL [IQR] levels were significantly higher in poor grade (14 [7-32] pg/mL) than good grade patients (7 [5-14] pg/mL). Within poor grade patients, median NfL [IQR] levels were significantly higher in non-survivors (19 [11-36] pg/mL) than survivors (7 [6-13] pg/mL).

CONCLUSION

In the entire aSAH cohort, plasma NfL has an acceptable predictive performance but does not improve clinical outcome prediction. However, NfL may have potential value in subgroups based on hemorrhage severity.

Comparison of scales for the evaluation of aneurysmal subarachnoid haemorrhage: a retrospective cohort study

BACKGROUND/OBJECTIVES

Aneurysmal subarachnoid haemorrhage (aSAH) is a life-threatening event with major complications. Delayed cerebral infarct (DCI) occurs most frequently 7 days after aSAH and can last for a prolonged period. To determine the most predictive radiological scales in grading subarachnoid or ventricular haemorrhage or both for functional outcome at 3 months in a large aSAH population, we conducted a single-centre retrospective study.

METHODS

A 3-year single-centre retrospective cohort study of 230 patients hospitalised for aSAH was analysed. Initial computed tomography (CT) scans in patients hospitalised for aSAH were blindly assessed using eight grading systems: the Fisher grade, modified Fisher grade, Barrow Neurological Institute scale, Hijdra scale, Intraventricular Haemorrhage (IVH) score, Graeb score and LeRoux score.

RESULTS

Of 200 patients with aSAH who survived to day 7 and were included for DCI analysis, 39% of cases were complicated with DCI. The Hijdra scale was the best predictor for DCI, with a receiver operating characteristic area under the curve (ROCAUC) of 0.80 (95% confidence interval (CI), 0.74-0.85). The IVH score was the most effective grading system for predicting acute hydrocephalus, with a ROCAUC of 0.85 (95% CI, 0.79-0.89). In multivariate analysis, the Hijdra scale was the best predictor of the occurrence of DCI (hazard ratio, 1.18; 95% CI, 1.10-1.25).

CONCLUSIONS

Although these results have yet to be prospectively confirmed, our findings suggest that the Hijdra scale may be a good predictor of DCI and could be useful in daily clinical practice.

CLINICAL RELEVANCE STATEMENT

Better assessment of subarachnoid haemorrhage patients would allow for better prognostication and management of expectations, as well as referral for appropriate services and helping to appropriate use limited critical care resources.

KEY POINTS

Aneurysmal subarachnoid haemorrhage is a life-threatening event that causes severe disability and leads to major complications such as delayed cerebral infarction. Accurate assessment of the amount of blood in the subarachnoid spaces on computed tomography with the Hijdra scale can better predict the risk of delayed cerebral infarct. The Hijdra scale could be a good triage tool for subarachnoid haemorrhage patients.

Intracranial aneurysms in patients with acute ischemic stroke prevalence and influence on mechanical thrombectomy over 14 years in a tertiary-care center

INTRODUCTION

The prevalence of intracranial aneurysms (IA) in patients with acute ischemic stroke (AIS) requiring mechanical thrombectomy (MT) is unclear.

OBJECTIVE

To describe the prevalence of IA in patients with AIS and their influence on MT.

MATERIALS & METHODS

This is a retrospective cohort study on all patients admitted with a diagnosis of AIS from January 2008 to March 2022 at a tertiary academic center. The records were reviewed for demographic, clinical, imaging, and outcomes data. Only patients who had CTA at admission were included in this analysis.

RESULTS

Among 2265 patients admitted with AIS, this diagnosis was confirmed in 2113 patients (93.3 %). We included 1111 patients (52.6 %) who had head CTA and 321 (28.9 %) who underwent MT. The observed prevalence of aneurysms on CTA was 4.5 % (50/1111 patients), and 8 (16 %) had multiple aneurysms. MT was performed in 7 patients harboring IAs: 6 ipsilateral (5 proximal and 1 distal to the occlusion)and 1 contralateral aneurysm.. The patient with a contralateral aneurysm had a TICI 2B score In patients with ipsilateral aneurysms, TICI 2B or 3 was achieved in 3 cases (50 %), which is significantly lower than historical control of MT (91.6 %) without IA (p = 0.01). No aneurysms ruptured during MT. The aneurysm noted distal to the occlusion was mycotic.

CONCLUSION

In this analysis, the observed prevalence of IA in patients with AIS was 4.5%. Ipsilateral aneurysms (proximal or distal to the occlusion site) deserve particular attention, given the potential risk of rupture during MT. Aneurysms located distal to the occlusion were mycotic and the rate of recanization in patients with ipsilateral aneurysms was low compared to historical controls. Further studies are needed to improve the outcomes in patients with IA requiring MT.

Intraparenchymal near-infrared spectroscopy for detection of delayed cerebral ischemia in poor-grade aneurysmal subarachnoid hemorrhage

OBJECTIVE

Detection of delayed cerebral ischemia (DCI) is challenging in comatose patients with poor-grade aneurysmal subarachnoid hemorrhage (aSAH). Brain tissue oxygen pressure (PbtO2) monitoring may allow early detection of its occurrence. Recently, a probe for combined measurement of intracranial pressure (ICP) and intraparenchymal near-infrared spectroscopy (NIRS) has become available. In this pilot study, the parameters PbtO2, Hboxy, Hbdeoxy, Hbtotal and rSO2 were measured in parallel and evaluated for their potential to detect perfusion deficits or cerebral infarction.

METHODS

In patients undergoing multimodal neuromonitoring due to poor neurological condition after aSAH, Clark oxygen probes, microdialysis and NIRS-ICP probes were applied. DCI was suspected when the measured parameters in neuromonitoring deteriorated. Thus, perfusion CT scan was performed as follow up, and DCI was confirmed as perfusion deficit. Median values for PbtO2, Hboxy, Hbdeoxy, Hbtotal and rSO2 in patients with perfusion deficit (Tmax > 6 s in at least 1 vascular territory) and/or already demarked infarcts were compared in 24- and 48-hour time frames before imaging.

RESULTS

Data from 19 patients (14 University Hospital Zurich, 5 Charité Universitätsmedizin Berlin) were prospectively collected and analyzed. In patients with perfusion deficits, the median values for Hbtotal and Hboxy in both time frames were significantly lower. With perfusion deficits, the median values for Hboxy and Hbtotal in the 24 h time frame were 46,3 [39.6, 51.8] µmol/l (no perfusion deficits 53 [45.9, 55.4] µmol/l, p = 0.019) and 69,3 [61.9, 73.6] µmol/l (no perfusion deficits 74,6 [70.1, 79.6] µmol/l, p = 0.010), in the 48 h time frame 45,9 [39.4, 51.5] µmol/l (no perfusion deficits 52,9 [48.1, 55.1] µmol/l, p = 0.011) and 69,5 [62.4, 74.3] µmol/l (no perfusion deficits 75 [70,80] µmol/l, p = 0.008), respectively. In patients with perfusion deficits, PbtO2 showed no differences in both time frames. PbtO2 was significantly lower in patients with infarctions in both time frames. The median PbtO2 was 17,3 [8,25] mmHg (with no infarctions 29 [22.5, 36] mmHg, p = 0.006) in the 24 h time frame and 21,6 [11.1, 26.4] mmHg (with no infarctions 31 [22,35] mmHg, p = 0.042) in the 48 h time frame. In patients with infarctions, the median values of parameters measured by NIRS showed no significant differences.

CONCLUSIONS

The combined NIRS-ICP probe may be useful for early detection of cerebral perfusion deficits and impending DCI. Validation in larger patient collectives is needed.

Investigation of the morphometric characteristics of internal carotid artery between sexes and in patients with intracranial aneurysms

PURPOSE

The purpose of this study is to investigate the morphometric properties of the internal carotid artery (ICA) by measuring the diameters and angles of its segments and exploring variations related to sex and the presence of aneurysms.

METHODS

Digital subtraction angiography (DSA) images were utilized from 130 aneurysm patients and 75 non-aneurysm individuals to create 3D ICA models using 3D Slicer software. Segment diameters were measured via Autodesk Meshmixer 3.5.474 and angles were evaluated using ImageJ software.

RESULTS

In total, DSA images of 130 aneurysm patients and 75 individuals with normally reported carotid systems were evaluated. It was found that the intracranial aneurysms (IAs) were predominantly formed on the anterior cerebral artery (ACA) in males (%43), whereas in females IAs were frequently localized in the C6 segment (31.7%) and middle cerebral artery (MCA) (30.2%). In the control group, the evaluation of gender differences in segment diameters and angles revealed that males had significantly larger C4 and C5 segment diameters (4.62 vs. 4.32 mm and 4.41 vs. 4.09 mm, respectively) and a greater C6 angle (146.9° vs. 139.7°) compared to females. Comparisons between patients with an aneurysm at the anterior cerebral artery (ACA) and the control group revealed that the ACA group had wider diameters in the C1 (4.88 vs. 4.53 mm), C3 (4.65 vs. 4.4 mm), C5 (4.51 vs. 4.25 mm), and ACA (2.36 vs. 2.06 mm) segments. Additionally, the ACA group had wider angles in the ACA (104.1° vs. 94.1°) and C6 segments (147.7° vs. 143.3°), whereas the control group exhibited wider angles in the middle cerebral artery (MCA) segment (141.5° vs. 135.5°) compared to the ACA aneurysm group. Patients with anterior cerebral artery (ACA) aneurysms exhibited larger diameters in C1, C3, C5, C6, and ACA segments compared to the control group. Additionally, while the control group had larger MCA angle, patients with ACA aneurysms had larger angles in C6 segment and ACA.

CONCLUSION

Our results demonstrated that formation of aneurysms is affected by anatomical configuration of the ICA as well as sex characteristics, particularly regarding the ACA and MCA bifurcation angles, which showed associations with aneurysms in the respective branches.

High-frequency optical coherence tomography for endovascular management of cerebral aneurysms

Endovascular management of intracranial aneurysms has become the mainstay of treatment in recent years; however, retreatment rates remain as high as 1 in 5. High-frequency optical coherence tomography (HF-OCT) is an emerging imaging modality for the assessment, treatment and follow-up of cerebral aneurysms. EMBASE and SCOPUS databases were searched for studies relating to the management of intracranial aneurysm with OCT. A combination of keywords were used including 'cerebral aneurysm', 'intracranial aneurysm', 'high-frequency optical coherence tomography', 'optical coherence tomography', and 'optical frequency domain imaging'. There were 23 papers included in this review. For the assessment of intracranial aneurysm, OCT was able to accurately assess aneurysm morphology as well as detailed analysis of arterial wall layers. During IA treatment, OCT was used to assess and troubleshoot stent placement to optimise successful isolation from the circulation. In the follow-up period, endothelial growth patterns were visualised by OCT imaging. OCT shows promise for the treatment of IAs at all stages of management. Due to the novel development of HF-OCT, there is limited longitudinal data in human studies. Further research in this area is required with a focus specifically on long-term treatment outcomes in humans.

It Is Necessary to Pay Attention to Where the Pcom Originate from the Aneurysm to Treat with FD

Objective  With the expansion of indications of flow diverter (FD) for cerebral aneurysms, FD placement for posterior communicating artery (Pcom) aneurysms has been approved. However, it is controversial whether Pcom aneurysms should be treated with FD or not. In this study, we report the outcome of FD treatment for Pcom aneurysms in Japan. Materials and Methods  We retrospectively analyzed 36 patients with 38 aneurysms treated with FD placement for Pcom aneurysms between 2015 and 2021 in our hospital. We divided our cases into complete occlusion (CO) and non-CO groups. And we extracted contributing factors to CO using multivariate analysis. We also compared the complications rate among the three types of FDs. Results  CO was obtained in 29 cases (79.3%), and complications were observed in 3 cases (7.9%). Multivariate analysis revealed that the type of Pcom branch from the aneurysmal dome was a significant factor contributing to CO (odds ratio: 0.0052, 95% confidence interval 0.000048-0.584, p  = 0.029). In terms of complications, complication rate was significantly higher in the Flow-Redirection Endoluminal Device (FRED) group ( p  = 0.0491). Conclusion  The outcome for Pcom aneurysms treated by FD was acceptable. When treating, we must pay attention to where Pcom originates. Achieving CO with FD is difficult for aneurysms where the Pcom branches from the dome. Furthermore, when treating Pcom aneurysms with FRED, it is necessary to be careful about thromboembolic complications.

Changes in arterial myocyte excitability induced by subarachnoid hemorrhage in a rat model

Aneurismal subarachnoid hemorrhage (aSAH) is a neurovascular disease produced by the rupture of the cerebral arteries and the extravasation of blood to the subarachnoid space and is accompanied by severe comorbidities. Secondarily associated vasospasm is one of the main side effects after hydrocephalus and possible rebleeding. Here, we analyze the alterations in function in the arteries of a rat model of SAH. For this, autologous blood was injected into the cisterna magna. We performed electrophysiological, microfluorimetric, and molecular biology experiments at different times after SAH to determine the functional and molecular changes induced by the hemorrhage. Our results confirmed that in SAH animals, arterial myocytes were depolarized on days 5 and 7, had higher [Ca2+]i on baseline, peaks and plateaus, and were more excitable at low levels of depolarization on day 7, than in the control and sham animals. Microarray analysis showed that, on day 7, the sets of genes related to voltage-dependent Ca2+ channels and K+ dynamics in SAH animals decreased, while the voltage-independent Ca2+ dynamics genes were over-represented. In conclusion, after SAH, several mechanisms involved in arterial reactivity were altered in our animal model, suggesting that there is no unique cause of vasospasm and alterations in several signaling pathways are involved in its development.

Impact of fludrocortisone on the outcomes of subarachnoid hemorrhage patients: A retrospective analysis

BACKGROUND

Whether the use of fludrocortisone affects outcomes of patients with aneurysmal subarachnoid hemorrhage (aSAH).

METHODS

We conducted a retrospective analysis of 78 consecutive patients with a ruptured aSAH at a single academic center in the United States. The primary outcome was the score on the modified Rankin scale (mRS, range, 0 [no symptoms] to 6 [death]) at 90 days. The primary outcome was adjusted for age, hypertension, aSAH grade, and time from aSAH onset to aneurysm treatment. Secondary outcomes were neurologic and cardiopulmonary dysfunction events.

RESULTS

Among 78 patients at a single center, the median age was 58 years [IQR, 49 to 64.5]; 64 % were female, and 41 (53 %) received fludrocortisone. The adjusted common odds ratio, aOR, of a proportional odds regression model of fludrocortisone use with mRS was 0.33 (95 % CI, 0.14-0.80; P = 0.02), with values <1.0 favoring fludrocortisone. Organ-specific dysfunction events were not statistically different: delayed cerebral ischemia (22 % vs. 39 %, P = 0.16); cardiac dysfunction (0 % vs. 11 %; P = 0.10); and pulmonary edema (15 % vs. 8 %; P = 0.59).

CONCLUSIONS

The risk of disability or death at 90 days was lower with the use of fludrocortisone in aSAH patients.

Efficacy of an intervention program to prevent patient safety indicators in aneurysmal subarachnoid haemorrhage

OBJECTIVE

Patient safety indicators (PSI) are a set of potentially preventable events related to patient safety and opportunities for improvement. Eight pertinent PSI have been identified in patients with aneurysmal subarachnoid haemorrhage (ASAH), such as decubitus ulcer, and central line-related bacteraemia. Our aim was to evaluate the efficacy of a health care quality protocol to prevent the appearance of PSI in ASAH patients.

METHODS

Adult patients treated for ASAH were included in a retrospective control group of 35 patients and a prospective experimental group of 35 patients when the prevention program was implemented. We evaluated the occurrence of PSI, and its relation to age, sex, Hunt and Hess scale grade, type of aneurysm treatment, length of hospital stay, and Glasgow Outcome Scale scores.

RESULTS

Both groups had similar characteristics except for a longer hospital stay in the control group. The overall PSI prevalence decreased significantly in the experimental group compared to the control group. The experimental group had a decreased risk for having at least one PSI: OR = 0.21 (0.08-0.57, CI 95%). The absolute risk reduction is 37.1% (58.9%-15.4%), the preventable fraction for the population is 28.3% (10.6%-40.0%), and the number needed to treat is 2.69.

CONCLUSIONS

The health care quality protocol is effective to prevent ISP in ASAH patients. Implementing this prevention program has no effect on the neurological state of the patient at the hospital discharge. Still, it is successful in decreasing the PSI prevalence and the days of hospital stay.

Time-of-Flight MRA of Intracranial Aneurysms with Interval Surveillance, Clinical Segmentation and Annotations

Intracranial aneurysms (IAs) are present in 2-6% of the global population and can be catastrophic upon rupture with a mortality rate of 30-50%. IAs are commonly detected through time-of-flight magnetic resonance angiography (TOF-MRA), however, this data is rarely available for research and training purposes. The provision of imaging resources such as TOF-MRA images is imperative to develop new strategies for IA detection, rupture prediction, and surgical training. To support efforts in addressing data availability bottlenecks, we provide an open-access TOF-MRA dataset comprising 63 patients, of which 24 underwent interval surveillance imaging by TOF-MRA. Patient scans were evaluated by a neuroradiologist, providing aneurysm and vessel segmentations, clinical annotations, 3D models, in addition to 3D Slicer software environments containing all this data for each patient. This dataset is the first to provide interval surveillance imaging for supporting the understanding of IA growth and stability. This dataset will support computational and experimental research into IA dynamics and assist surgical and radiology training in IA treatment.

Association of serum uric acid level with intracranial aneurysms: A Mendelian randomization study

Objective

Numerous studies have posited the involvement of serum uric acid (SUA) in the pathogenesis and progression of various cardiovascular diseases, particularly aortic aneurysms. However, the casual effect of SUA level on intracranial aneurysms (IAs) was rarely studied. Consequently, we aimed to explore the causal association between SUA and IAs using Mendelian randomization (MR) analysis.

Methods

We conducted a two-sample MR analysis with SUA as the exposure variable and IAs as the outcome variable. Genome-wide association study (GWAS) datasets for SUA were acquired from the Open GWAS catalog, including 389,404 European and 129,405 East Asian individuals. The dataset for IAs was sourced from a meta-analysis of GWASs comprising 317,636 individuals across different ancestral populations (European: 7495 cases and 71,934 controls; East Asian: 3259 cases and 234,948 controls). The MR analyses were performed according to populations (European and East Asian) and IAs status [unruptured IAs (uIAs) or aneurysmal subarachnoid hemorrhage (aSAH)], respectively. The inverse variance weighted (IVW) method was employed as primary analysis to discern causal estimates.

Results

Our findings revealed that an elevated genetically predicted SUA level (mg/dL) correlated with an increased risk of IAs among the European population (OR = 1.29 [95%CI:1.05-1.57], P = 0.013) and East Asian population (OR = 1.56 [95%CI: 1.27-1.92], P < 0.001). Among European individuals, subgroup analysis indicated a persistent causal association of SUA with uIAs (OR = 1.50 [95%CI: 1.08-2.08], P = 0.015) and aSAH (OR = 1.26 [95%CI: 1.00-1.60], P = 0.049). However, subgroup analysis in East Asian populations was not conducted due to the lack of separate data on uIAs and aSAH.

Conclusions

Our MR analysis demonstrated a causal relationship between elevated SUA levels and an amplified risk of IAs. Further rigorous investigations are imperative to provide evidence and elucidate the underlying mechanisms.

Sex-Related Differences in Mortality, Delayed Cerebral Ischemia, and Functional Outcomes in Patients with Aneurysmal Subarachnoid Hemorrhage: A Systematic Review and Meta-Analysis

Background/Objective: Sex-related differences among patients with aneurysmal subarachnoid hemorrhage (aSAH) and their potential clinical implications have been insufficiently investigated. To address this knowledge gap, we conduct a comprehensive systematic review and meta-analysis. Methods: Sex-specific differences in patients with aSAH, including mortality, delayed cerebral ischemia (DCI), and functional outcomes were assessed. The functional outcome was dichotomized into favorable or unfavorable based on the modified Rankin Scale (mRS), Glasgow Outcome Scale (GOS), and Glasgow Outcome Scale Extended (GOSE). Results: Overall, 2823 studies were identified in EMBASE, MEDLINE, PubMed, and by manual search on 14 February 2024. After an initial assessment, 74 studies were included in the meta-analysis. In the analysis of mortality, including 18,534 aSAH patients, no statistically significant differences could be detected (risk ratio (RR) 0.99; 95% CI, 0.90-1.09; p = 0.91). In contrast, the risk analysis for DCI, including 23,864 aSAH patients, showed an 11% relative risk reduction in DCI in males versus females (RR, 0.89; 95% CI, 0.81-0.97; p = 0.01). The functional outcome analysis (favorable vs. unfavorable), including 7739 aSAH patients, showed a tendency towards better functional outcomes in men than women; however, this did not reach statistical significance (RR, 1.02; 95% CI, 0.98-1.07; p = 0.34). Conclusions: In conclusion, the available data suggest that sex/gender may play a significant role in the risk of DCI in patients with aSAH, emphasizing the need for sex-specific management strategies.

Sodium and Its Impact on Outcome After Aneurysmal Subarachnoid Hemorrhage in Patients With and Without Delayed Cerebral Ischemia

OBJECTIVES

To perform a detailed examination of sodium levels, hyponatremia and sodium fluctuations, and their association with delayed cerebral ischemia (DCI) and poor outcome after aneurysmal subarachnoid hemorrhage (aSAH).

DESIGN

An observational cohort study from a prospective SAH Registry.

SETTING

Tertiary referral center focused on SAH treatment in the Amsterdam metropolitan area.

PATIENTS

A total of 964 adult patients with confirmed aSAH were included between 2011 and 2021.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A total of 277 (29%) developed DCI. Hyponatremia occurred significantly more often in DCI patients compared with no-DCI patients (77% vs. 48%). Sodium levels, hyponatremia, hypernatremia, and sodium fluctuations did not predict DCI. However, higher sodium levels were significantly associated with poor outcome in DCI patients (DCI onset -7, DCI +0, +1, +2, +4, +5, +8, +9 d), and in no-DCI patients (postbleed day 6-10 and 12-14). Also, hypernatremia and greater sodium fluctuations were significantly associated with poor outcome in both DCI and no-DCI patients.

CONCLUSIONS

Sodium levels, hyponatremia, and sodium fluctuations were not associated with the occurrence of DCI. However, higher sodium levels, hypernatremia, and greater sodium fluctuations were associated with poor outcome after aSAH irrespective of the presence of DCI. Therefore, sodium levels, even with mild changes in levels, warrant close attention.

Towards the mechanical characterisation of unruptured intracranial aneurysms: Numerical modelling of interactions between a deformation device and the aneurysm wall

Intracranial aneurysm is a critical pathology related to the arterial wall deterioration. This work is an essential aspect of a large scale project aimed at providing clinicians with a non-invasive patient-specific decision support tool regarding the rupture risk assessment. A machine learning algorithm links the aneurysm shape observed and a database of UIA clinical images associated with in vivo wall mechanical properties and rupture characterisation. The database constitution is derived from a device prototype coupled with medical imaging. It provides the mechanical characterisation of the aneurysm from the wall deformation obtained by inverse analysis based on the variation of luminal volume. Before performing in vivo tests of the device on small animals, a numerical model was built to quantify the device's impact on the aneurysm wall under natural blood flow conditions. As the clinician will never be able to precisely situate the device, several locations were considered. In preparation for the inverse analysis procedure, artery material laws of increasing complexity were studied (linear elastic, hyper elastic Fung-like). Considering all the device locations and material laws, the device induced relative displacements to the Systole peak (worst case scenario with the highest mechanical stimulus linked to the blood flow) ranging from 375 μm to 1.28 mm. The variation of luminal volume associated with the displacements was between 0.95 % and 4.3 % compared to the initial Systole volume of the aneurysm. Significant increase of the relative displacements and volume variations were found with the study of different cardiac cycle moments between the blood flow alone and the device application. For forthcoming animal model studies, Spectral Photon CT Counting, with a minimum spatial resolution of 250 μm, was selected as the clinical imaging technique. Based on this preliminary study, the displacements and associated volume variations (baseline for inverse analyse), should be observable and exploitable.