ARISE I Consensus Review on the Management of Intracranial Aneurysms.

BACKGROUND: Intracranial aneurysms (IAs) remain a challenging neurological diagnosis associated with significant morbidity and mortality. There is a plethora of microsurgical and endovascular techniques for the treatment of both ruptured and unruptured aneurysms. There is no definitive consensus as to the best treatment option for this cerebrovascular pathology. The Aneurysm, Arteriovenous Malformation, and Chronic Subdural Hematoma Roundtable Discussion With Industry and Stroke Experts discussed best practices and the most promising approaches to improve the management of brain aneurysms. METHODS: A group of experts from academia, industry, and federal regulators convened to discuss updated clinical trials, scientific research on preclinical system models, management options, screening and monitoring, and promising novel device technologies, aiming to improve the outcomes of patients with IA. RESULTS: Aneurysm, Arteriovenous Malformation, and Chronic Subdural Hematoma Roundtable Discussion With Industry and Stroke Experts suggested the incorporation of artificial intelligence to capture sequential aneurysm growth, identify predictors of rupture, and predict the risk of rupture to guide treatment options. The consensus strongly recommended nationwide systemic data collection of unruptured IA radiographic images for the analysis and development of machine learning algorithms for rupture risk. The consensus supported centers of excellence for preclinical multicenter trials in areas such as genetics, cellular composition, and radiogenomics. Optical coherence tomography and magnetic resonance imaging contrast-enhanced 3T vessel wall imaging are promising technologies; however, more data are needed to define their role in IA management. Ruptured aneurysms are best managed at large volume centers, which should include comprehensive patient management with expertise in microsurgery, endovascular surgery, neurology, and neurocritical care. CONCLUSIONS: Clinical and preclinical studies and scientific research on IA should engage high-volume centers and be conducted in multicenter collaborative efforts. The future of IA diagnosis and monitoring could be enhanced by the incorporation of artificial intelligence and national radiographic and biologic registries. A collaborative effort between academic centers, government regulators, and the device industry is paramount for the adequate management of IA and the advancement of the field.

Exploring the causal role of immune cells in cerebral aneurysm through single-cell transcriptomics and Mendelian randomization analysis.

Cerebral aneurysm (CA) represents a significant clinical challenge, characterized by pathological dilation of cerebral arteries. Recent evidence underscores the crucial involvement of immune cells in CA pathogenesis. This study aims to explore the complex interplay between immune cells and CA formation. We analyzed single-cell RNA sequencing data from the GSE193533 dataset, focusing on unruptured CA and their controls. Comprehensive cell-type identification and pseudo-time trajectory analyses were conducted to delineate the dynamic shifts in immune cell populations. Additionally, a two-sample Mendelian randomization (MR) approach was employed to investigate the causal influence of various immunophenotypes on CA susceptibility and the reciprocal effect of CA formation on immune phenotypes. Single-cell transcriptomic analysis revealed a progressive loss of vascular smooth muscle cells (VSMCs) and an increase in monocytes/macrophages (Mo/MΦ) and other immune cells, signifying a shift from a structural to an inflammatory milieu in CA evolution. MR analysis identified some vital immunophenotypes, such as CD64 on CD14+ CD16+ monocytes (OR: 1.236, 95% CI: 1.064-1.435, P = 0.006), as potential risk factors for CA development, while others, like CD28- CD8br %CD8br (OR: 0.883, 95% CI: 0.789-0.988, P = 0.030), appeared protective. Reverse MR analysis demonstrated that CA formation could modulate specific immunophenotypic expressions, highlighting a complex bidirectional interaction between CA pathology and immune response. This study underscores the pivotal role of immune cells in this process through the integration of single-cell transcriptomics with MR analysis, offering a comprehensive perspective on CA pathogenesis, and potentially guiding future therapeutic strategies targeting specific immune pathways.

The SNHG12/microRNA-15b-5p/MYLK axis regulates vascular smooth muscle cell phenotype to affect intracranial aneurysm formation.

OBJECTIVE: This research was dedicated to investigating the impact of the SNHG12/microRNA (miR)-15b-5p/MYLK axis on the modulation of vascular smooth muscle cell (VSMC) phenotype and the formation of intracranial aneurysm (IA). METHODS: SNHG12, miR-15b-5p and MYLK expression in IA tissue samples from IA patients were tested by RT-qPCR and western blot. Human aortic vascular smooth muscle cells (VSMCs) were cultivated with H2O2 to mimic IA-like conditions in vitro, and the cell proliferation and apoptosis were measured by MTT assay and Annexin V/PI staining. IA mouse models were established by induction with systemic hypertension combined with elastase injection. The blood pressure in the tail artery of mice in each group was assessed and the pathological changes in arterial tissues were observed by HE staining and TUNEL staining. The expression of TNF-α and IL-1ß, MCP-1, iNOS, caspase-3, and caspase-9 in the arterial tissues were tested by RT-qPCR and ELISA. The relationship among SNHG12, miR-15b-5p and MYLK was verified by bioinformatics, RIP, RNA pull-down, and luciferase reporter assays. RESULTS: The expression levels of MYLK and SNHG12 were down-regulated and that of miR-15b-5p was up-regulated in IA tissues and H2O2-treated human aortic VSMCs. Overexpressed MYLK or SNHG12 mitigated the decrease in proliferation and increase in apoptosis of VSMCs caused by H2O2 induction, and overexpression of miR-15b-5p exacerbated the decrease in proliferation and increase in apoptosis of VSMCs caused by H2O2 induction. Overexpression of miR-15b-5p reversed the H2O2-treated VSMC phenotypic changes caused by SNHG12 up-regulation, and overexpression of MYLK reversed the H2O2-treated VSMC phenotypic changes caused by up-regulation of miR-15b-5p. Overexpression of SNHG12 reduced blood pressure and ameliorated arterial histopathological damage and VSMC apoptosis in IA mice. The mechanical analysis uncovered that SNHG12 acted as an endogenous RNA that competed with miR-15b-5p, thus modulating the suppression of its endogenous target, MYLK. CONCLUSION: Decreased expression of SNHG12 in IA may contribute to the increasing VSMC apoptosis via increasing miR-15b-5p expression and subsequently decreasing MYLK expression. These findings provide potential new strategies for the clinical treatment of IA.

Hemodynamic Parameters in the Parent Arteries of Unruptured Intracranial Aneurysms Depend on Aneurysm Size and Are Different Compared to Contralateral Arteries: A 7 Tesla 4D Flow MRI Study.

BACKGROUND: Different Circle of Willis (CoW) variants have variable prevalences of aneurysm development, but the hemodynamic variation along the CoW and its relation to presence and size of unruptured intracranial aneurysms (UIAs) are not well known. PURPOSE: Gain insight into hemodynamic imaging markers of the CoW for UIA development by comparing these outcomes to the corresponding contralateral artery without an UIA using 4D flow magnetic resonance imaging (MRI). STUDY TYPE: Retrospective, cross-sectional study. SUBJECTS: Thirty-eight patients with an UIA, whereby 27 were women and a mean age of 62 years old. FIELD STRENGTH/SEQUENCE: Four-dimensional phase-contrast (PC) MRI with a 3D time-resolved velocity encoded gradient echo sequence at 7 T. ASSESSMENT: Hemodynamic parameters (blood flow, velocity pulsatility index [vPI], mean velocity, distensibility, and wall shear stress [peak systolic (WSSMAX ), and time-averaged (WSSMEAN )]) in the parent artery of the UIA were compared to the corresponding contralateral artery without an UIA and were related to UIA size. STATISTICAL TESTS: Paired t-tests and Pearson Correlation tests. The threshold for statistical significance was P < 0.05 (two-tailed). RESULTS: Blood flow, mean velocity, WSSMAX , and WSSMEAN were significantly higher, while vPI was lower, in the parent artery relative to contralateral artery. The WSSMAX of the parent artery significantly increased linearly while the WSSMEAN decreased linearly with increasing UIA size. CONCLUSIONS: Hemodynamic parameters and WSS differ between parent vessels of UIAs and corresponding contralateral vessels. WSS correlates with UIA size, supporting a potential hemodynamic role in aneurysm pathology. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY: Stage 2.

Somatic PDGFRB activating variants promote smooth muscle cell phenotype modulation in intracranial fusiform aneurysm.

BACKGROUND: The fusiform aneurysm is a nonsaccular dilatation affecting the entire vessel wall over a short distance. Although PDGFRB somatic variants have been identified in fusiform intracranial aneurysms, the molecular and cellular mechanisms driving fusiform intracranial aneurysms due to PDGFRB somatic variants remain poorly understood. METHODS: In this study, single-cell sequencing and immunofluorescence were employed to investigate the phenotypic changes in smooth muscle cells within fusiform intracranial aneurysms. Whole-exome sequencing revealed the presence of PDGFRB gene mutations in fusiform intracranial aneurysms. Subsequent immunoprecipitation experiments further explored the functional alterations of these mutated PDGFRB proteins. For the common c.1684 mutation site of PDGFRß, we established mutant smooth muscle cell lines and zebrafish models. These models allowed us to simulate the effects of PDGFRB mutations. We explored the major downstream cellular pathways affected by PDGFRBY562D mutations and evaluated the potential therapeutic effects of Ruxolitinib. RESULTS: Single-cell sequencing of two fusiform intracranial aneurysms sample revealed downregulated smooth muscle cell markers and overexpression of inflammation-related markers in vascular smooth muscle cells, which was validated by immunofluorescence staining, indicating smooth muscle cell phenotype modulation is involved in fusiform aneurysm. Whole-exome sequencing was performed on seven intracranial aneurysms (six fusiform and one saccular) and PDGFRB somatic mutations were detected in four fusiform aneurysms. Laser microdissection and Sanger sequencing results indicated that the PDGFRB mutations were present in smooth muscle layer. For the c.1684 (chr5: 149505131) site mutation reported many times, further cell experiments showed that PDGFRBY562D mutations promoted inflammatory-related vascular smooth muscle cell phenotype and JAK-STAT pathway played a crucial role in the process. Notably, transfection of PDGFRBY562D in zebrafish embryos resulted in cerebral vascular anomalies. Ruxolitinib, the JAK inhibitor, could reversed the smooth muscle cells phenotype modulation in vitro and inhibit the vascular anomalies in zebrafish induced by PDGFRB mutation. CONCLUSION: Our findings suggested that PDGFRB somatic variants played a role in regulating smooth muscle cells phenotype modulation in fusiform aneurysms and offered a potential therapeutic option for fusiform aneurysms.

Vertebral artery dissection caused by atlantoaxial dislocation in a patient with Marfan syndrome.

A small number of case reports have documented a link between atlantoaxial dislocation (AAD) and vertebral artery dissection (VAD), but this association has never been described in patients with hereditary connective tissue disorders. We present a case of an 18-year-old female patient, diagnosed with Marfan syndrome since the age of one, who underwent brain MRA for intracranial aneurysm screening revealing tortuosity of the internal carotid and vertebral arteries as well as atlantoaxial dislocation. Since the patient was asymptomatic, a wait-and-see approach was chosen, but a follow-up MRA after 18 months showed the appearance of a dissecting pseudoaneurysm of the V3 segment of the left vertebral artery. Despite the patient being still asymptomatic, it was decided to proceed with C1-C2 stabilization to prevent further vascular complications. Follow-up imaging showed realignment of the atlantoaxial joint and reduction of the dissecting pseudoaneurysm of the left vertebral artery. In our patient, screening MRA has led to the discovery of asymptomatic arterial and skeletal abnormalities which, if left untreated, might have led to severe cerebrovascular complications. Therefore, AAD correction or close monitoring with MRA should be provided to MFS patients with this craniovertebral junction anomaly, even if asymptomatic.

Development of an Injectable, ECM-Derivative Embolic for the Treatment of Cerebral Saccular Aneurysms.

Cerebral aneurysms are a source of neurological morbidity and mortality, most often as a result of rupture. The most common approach for treating aneurysms involves endovascular embolization using nonbiodegradable medical devices, such as platinum coils. However, the need for retreatment due to the recanalization of coil-treated aneurysms highlights the importance of exploring alternative solutions. In this study, we propose an injectable extracellular matrix-derived embolic formed in situ by Michael addition of gelatin-thiol (Gel-SH) and hyaluronic acid vinyl sulfone (HA-VS) that may be delivered with a therapeutic agent (here, RADA-SP) to fill and remodel aneurysmal tissue without leaving behind permanent foreign bodies. The injectable embolic material demonstrated rapid gelation under physiological conditions, forming a highly porous structure and allowing for cellular infiltration. The injectable embolic exhibited thrombogenic behavior in vitro that was comparable to that of alginate injectables. Furthermore, in vivo studies in a murine carotid aneurysm model demonstrated the successful embolization of a saccular aneurysm and extensive cellular infiltration both with and without RADA-SP at 3 weeks, with some evidence of increased vascular or fibrosis markers with RADA-SP incorporation. The results indicate that the developed embolic has inherent potential for acutely filling cerebrovascular aneurysms and encouraging the cellular infiltration that would be necessary for stable, chronic remodeling.

Enhanced vessel wall magnetic resonance imaging in the follow-up of intracranial aneurysms treated with flow diversion.

OBJECTIVE: This study aimed to compare the efficacy of enhanced 3D T1-weighted black-blood fast-spin-echo vessel wall magnetic resonance imaging (eVW-MRI) and time-of-flight magnetic resonance angiography (TOF MRA) for follow-up evaluation of aneurysms treated with flow diversion (FD). METHODS: Our study enrolled 77 patients harboring 84 aneurysms treated with FD. Follow-up was by MRI (eVW-MRI and TOF MRA) and digital subtraction angiography (DSA). Two radiologists, blinded to DSA examination results, independently evaluated the images of aneurysm occlusion and parent artery patency using the Kamran-Byrne Scale. Interobserver diagnostic agreement and intermodality diagnostic agreement were acquired. Pretreatment and follow-up aneurysm wall enhancement (AWE) patterns were collected. RESULTS: Based on the Kamran-Byrne Scale, the intermodality agreement between eVW-MRI and DSA was better than TOF MRA versus DSA for aneurysm remnant detection (weighted ĸ = 0.891 v. 0.553) and parent artery patency (ĸ = 0.950 v. 0.221). Even with the coil artifact, the consistency of eVW-MRI with DSA for aneurysm remnant detection was better than that of TOF MRA (weighted ĸ = 0.891 v. 0.511). The artifact of adjunctive coils might be more likely to affect the accuracy in evaluating parent artery patency with TOF MRA than with eVW-MRI (ĸ = 0.077 v. 0.788). The follow-up AWE patterns were not significantly associated with pretreatment AWE patterns and aneurysm occlusion. CONCLUSIONS: The eVW-MRI outperforms TOF MRA as a reliable noninvasive and nonionizing radioactive imaging method for evaluating aneurysm remnants and parent artery patency after FD. The significance of enhancement patterns on eVW-MRI sequences needs more exploration. CLINICAL RELEVANCE STATEMENT: The application of enhanced vessel wall magnetic resonance imaging has proven to be a promising tool to depict aneurysm remnant and parent artery stenosis in order to tailor the antiplatelet therapy strategy in patients after flow diversion. KEY POINTS: • Enhanced vessel wall magnetic resonance imaging has an emerging role in depicting aneurysm remnant and parent artery patency after flow diversion. • With or without the artifact from adjunctive coils, enhanced vessel wall magnetic resonance imaging was better than TOF MRA in detecting aneurysm residual and parent artery stenosis by using DSA imaging as the standard. • Enhanced vessel wall magnetic resonance imaging holds potential to be used as an alternative to DSA for routine aneurysm follow-up after flow diversion.

Wall permeability on magnetic resonance imaging is associated with intracranial aneurysm symptoms and wall enhancement.

OBJECTIVES: Wall remodeling and inflammation accompany symptomatic unruptured intracranial aneurysms (UIAs). The volume transfer constant (Ktrans) of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) reflects UIA wall permeability. Aneurysmal wall enhancement (AWE) on vessel wall MRI (VWI) is associated with inflammation. We hypothesized that Ktrans is related to symptomatic UIAs and AWE. METHODS: Consecutive patients with UIAs were prospectively recruited for 3-T DCE-MRI and VWI from January 2018 to March 2023. UIAs were classified as asymptomatic and symptomatic if associated with sentinel headache or oculomotor nerve palsy. Ktrans and AWE were assessed on DCE-MRI and VWI, respectively. AWE was evaluated using the AWE pattern and wall enhancement index (WEI). Spearman's correlation coefficient and univariate and multivariate analyses were used to assess correlations between parameters. RESULTS: We enrolled 82 patients with 100 UIAs (28 symptomatic and 72 asymptomatic). The median Ktrans (2.1 versus 0.4 min-1; p < 0.001) and WEI (1.5 versus 0.4; p < 0.001) were higher for symptomatic aneurysms than for asymptomatic aneurysms. Ktrans (odds ratio [OR]: 1.60, 95% confidence interval [95% CI]: 1.01-2.52; p = 0.04) and WEI (OR: 3.31, 95% CI: 1.05-10.42; p = 0.04) were independent risk factors for symptomatic aneurysms. Ktrans was positively correlated with WEI (Spearman's coefficient of rank correlation (rs) = 0.41, p < 0.001). The combination of Ktrans and WEI achieved an area under the curve of 0.81 for differentiating symptomatic from asymptomatic aneurysms. CONCLUSIONS: Ktrans may be correlated with symptomatic aneurysms and AWE. Ktrans and WEI may provide an additional value than the PHASES score for risk stratification of UIAs. CLINICAL RELEVANCE STATEMENT: The volume transfer constant (Ktrans) from DCE-MRI perfusion is associated with symptomatic aneurysms and provides additional value above the clinical PHASES score for risk stratification of intracranial aneurysms. KEY POINTS: • The volume transfer constant is correlated with intracranial aneurysm symptoms and aneurysmal wall enhancement. • Dynamic contrast-enhanced and vessel wall MRI facilitates understanding of the pathophysiological characteristics of intracranial aneurysm walls. • The volume transfer constant and wall enhancement index perform better than the traditional PHASES score in differentiating symptomatic aneurysms.

Gadolinium-enhanced intracranial aneurysm wall imaging and risk of aneurysm growth and rupture: a multicentre longitudinal cohort study.

OBJECTIVES: In patients with an unruptured intracranial aneurysm, gadolinium enhancement of the aneurysm wall is associated with growth and rupture. However, most previous studies did not have a longitudinal design and did not adjust for aneurysm size, which is the main predictor of aneurysm instability and the most important determinant of wall enhancement. We investigated whether aneurysm wall enhancement predicts aneurysm growth and rupture during follow-up and whether the predictive value was independent of aneurysm size. MATERIALS AND METHODS: In this multicentre longitudinal cohort study, individual patient data were obtained from twelve international cohorts. Inclusion criteria were as follows: 18 years or older with ≥ 1 untreated unruptured intracranial aneurysm < 15 mm; gadolinium-enhanced aneurysm wall imaging and MRA at baseline; and MRA or rupture during follow-up. Patients were included between November 2012 and November 2019. We calculated crude hazard ratios with 95%CI of aneurysm wall enhancement for growth (≥ 1 mm increase) or rupture and adjusted for aneurysm size. RESULTS: In 455 patients (mean age (SD), 60 (13) years; 323 (71%) women) with 559 aneurysms, growth or rupture occurred in 13/194 (6.7%) aneurysms with wall enhancement and in 9/365 (2.5%) aneurysms without enhancement (crude hazard ratio 3.1 [95%CI: 1.3-7.4], adjusted hazard ratio 1.4 [95%CI: 0.5-3.7]) with a median follow-up duration of 1.2 years. CONCLUSIONS: Gadolinium enhancement of the aneurysm wall predicts aneurysm growth or rupture during short-term follow-up, but not independent of aneurysm size. CLINICAL RELEVANCE STATEMENT: Gadolinium-enhanced aneurysm wall imaging is not recommended for short-term prediction of growth and rupture, since it appears to have no additional value to conventional predictors. KEY POINTS: • Although aneurysm wall enhancement is associated with aneurysm instability in cross-sectional studies, it remains unknown whether it predicts risk of aneurysm growth or rupture in longitudinal studies. • Gadolinium enhancement of the aneurysm wall predicts aneurysm growth or rupture during short-term follow-up, but not when adjusting for aneurysm size. • While gadolinium-enhanced aneurysm wall imaging is not recommended for short-term prediction of growth and rupture, it may hold potential for aneurysms smaller than 7 mm.

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.

Prevalence of pre-eclampsia in 265 patients with an intracranial aneurysm, 393 female relatives versus a control cohort: A case-control study.

BACKGROUND AND OBJECTIVES: There is emerging evidence on the connection between pre-eclampsia and saccular intracranial aneurysms (sIAs). Our aim was to study the prevalence of pre-eclampsia in sIA patients, their female relatives, and matched controls, and to examine familial sIA disease and familial pre-eclampsia in sIA patients' families. METHODS: We included all female sIA patients in the Kuopio Intracranial Aneurysm Patient and Family Database from 1995 to 2018. First, we identified the sIA patients, their female relatives, and matched population controls with the first birth in 1987 or later and studied the prevalence of pre-eclampsia. Second, all female sIA patients and all female relatives were analyzed for familial sIA disease and familial pre-eclampsia. Using the Finnish nationwide health registries, we obtained data on drug purchases, hospital diagnoses, and causes of death. RESULTS: In total, 265 sIA patients, 57 daughters, 167 sisters, 169 nieces, and 546 matched controls had the first birth in 1987 or later. Among them, 29 (11%) sIA patients, 5 (9%) daughters, 10 (6%) sisters, 10 (6%) nieces, and 32 (6%) controls had pre-eclampsia. Of all the 1895 female sIA patients and 12,141 female relatives, 68 sIA patients and 375 relatives had pre-eclampsia, including 32 families with familial pre-eclampsia. CONCLUSIONS: Pre-eclampsia was significantly more common in the sIA patients than in their matched controls. Familial sIA disease and familial pre-eclampsia co-occurred in seven families. Further studies of the mechanisms by which pre-eclampsia could affect the walls of brain arteries and increase the rupture risk in sIA disease are indicated.

Analysis of aneurysmal subarachnoid hemorrhage as a multistep process.

BACKGROUND AND PURPOSE: Aneurysmal subarachnoid hemorrhage (ASAH) is a complex disease with higher incidence in women compared to men and in Japan compared to other countries. It was hypothesized that ASAH is consistent with a multistep model of disease. The following assessments were made: (1) the number of steps needed for the disease to occur and (2) whether this number may be different in female versus male and in Japanese versus non-Japanese patients. METHODS: Incidence data were generated from a meta-analysis on ASAH incidence until 2017, which was supplemented with a literature search from 2017 to April 2023. Age- and sex-adjusted incidences per 10-year age groups were calculated and the logarithm of age-specific incidence against the logarithm of age was regressed with least-squares regression. RESULTS: In 2317 ASAH patients a linear relationship between logarithm of incidence and logarithm of age was found with a slope estimate of 3.13 (95% confidence interval 2.60-3.65), consistent with a four-step process. Similar estimates were found for female, male, Japanese and non-Japanese patients. CONCLUSIONS: Our results suggest that ASAH is a four-step process, also in subgroups with higher ASAH incidence. Elucidation of the exact nature of these steps can provide important clues for identification of disease mechanisms underlying ASAH.

Dietary Iron Restriction Protects against Aneurysm Rupture in a Mouse Model of Intracranial Aneurysm.

INTRODUCTION: Iron accumulation in vessel walls induces oxidative stress and inflammation, which can cause cerebrovascular damage, vascular wall degeneration, and intracranial aneurysmal formation, growth, and rupture. Subarachnoid hemorrhage from intracranial aneurysm rupture results in significant morbidity and mortality. This study used a mouse model of intracranial aneurysm to evaluate the effect of dietary iron restriction on aneurysm formation and rupture. METHODS: Intracranial aneurysms were induced using deoxycorticosterone acetate-salt-induced hypertension and a single injection of elastase into the cerebrospinal fluid of the basal cistern. Mice were fed an iron-restricted diet (n = 23) or a normal diet (n = 25). Aneurysm rupture was detected by neurological symptoms, while the presence of intracranial aneurysm with subarachnoid hemorrhage was confirmed by post-mortem examination. RESULTS: The aneurysmal rupture rate was significantly lower in iron-restricted diet mice (37%) compared with normal diet mice (76%; p < 0.05). Serum oxidative stress, iron accumulation, macrophage infiltration, and 8-hydroxy-2'-deoxyguanosine in the vascular wall were lower in iron-restricted diet mice (p < 0.01). The areas of iron positivity were similar to the areas of CD68 positivity and 8-hydroxy-2'-deoxyguanosine in both normal diet and iron-restricted diet mouse aneurysms. CONCLUSIONS: These findings suggest that iron is involved in intracranial aneurysm rupture via vascular inflammation and oxidative stress. Dietary iron restriction may have a promising role in preventing intracranial aneurysm rupture.

The Role of Long Noncoding RNAs in Vascular Smooth Muscle Cell Phenotype and the Pathogenesis of Cardiovascular and Cerebrovascular Aneurysms.

ABSTRACT: Aneurysms are localized dilations of blood vessels, which can expand to 50% of the original diameter. They are more common in cardiovascular and cerebrovascular vessels. Rupture is one of the most dangerous complications. The pathophysiology of aneurysms is complex and diverse, often associated with progressive vessel wall dysfunction resulting from vascular smooth muscle cell death and abnormal extracellular matrix synthesis and degradation. Multiple studies have shown that long noncoding RNAs (lncRNAs) play a significant role in the progression of cardiovascular and cerebrovascular diseases. Therefore, it is necessary to find and summarize them. LncRNAs control gene expression and disease progression by regulating target mRNA or miRNA and are biomarkers for the diagnosis and prognosis of aneurysmal cardiovascular and cerebrovascular diseases. This review explores the role, mechanism, and clinical value of lncRNAs in aneurysms, providing new insights for a deeper understanding of the pathogenesis of cardiovascular and cerebrovascular aneurysms.

Personalized decision-making for aneurysm treatment of aneurysmal subarachnoid hemorrhage: development and validation of a clinical prediction tool.

BACKGROUND: In patients with aneurysmal subarachnoid hemorrhage suitable for endovascular coiling and neurosurgical clip-reconstruction, the aneurysm treatment decision-making process could be improved by considering heterogeneity of treatment effect and durability of treatment. We aimed to develop and validate a tool to predict individualized treatment benefit of endovascular coiling compared to neurosurgical clip-reconstruction. METHODS: We used randomized data (International Subarachnoid Aneurysm Trial, n = 2143) to develop models to predict 2-month functional outcome and to predict time-to-rebleed-or-retreatment. We modeled for heterogeneity of treatment effect by adding interaction terms of treatment with prespecified predictors and with baseline risk of the outcome. We predicted outcome with both treatments and calculated absolute treatment benefit. We described the patient characteristics of patients with ≥ 5% point difference in the predicted probability of favorable functional outcome (modified Rankin Score 0-2) and of no rebleed or retreatment within 10 years. Model performance was expressed with the c-statistic and calibration plots. We performed bootstrapping and leave-one-cluster-out cross-validation and pooled cluster-specific c-statistics with random effects meta-analysis. RESULTS: The pooled c-statistics were 0.72 (95% CI: 0.69-0.75) for the prediction of 2-month favorable functional outcome and 0.67 (95% CI: 0.63-0.71) for prediction of no rebleed or retreatment within 10 years. We found no significant interaction between predictors and treatment. The average predicted benefit in favorable functional outcome was 6% (95% CI: 3-10%) in favor of coiling, but 11% (95% CI: 9-13%) for no rebleed or retreatment in favor of clip-reconstruction. 134 patients (6%), young and in favorable clinical condition, had negligible functional outcome benefit of coiling but had a ≥ 5% point benefit of clip-reconstruction in terms of durability of treatment. CONCLUSIONS: We show that young patients in favorable clinical condition and without extensive vasospasm have a negligible benefit in functional outcome of endovascular coiling - compared to neurosurgical clip-reconstruction - while at the same time having a substantially lower probability of retreatment or rebleeding from neurosurgical clip-reconstruction - compared to endovascular coiling. The SHARP prediction tool ( https://sharpmodels.shinyapps.io/sharpmodels/ ) could support and incentivize a multidisciplinary discussion about aneurysm treatment decision-making by providing individualized treatment benefit estimates.

Neuroform atlas stent treatment for 533 intracranial aneurysms in a large Chinese cohort: complication risk factor analysis.

BACKGROUND: The newest generation of Neuroform Atlas stent™ (Stryker, Fremont, California) represents a recent advance of cerebral laser-cut microstents for the treatment of intracranial wide-necked aneurysms, and postoperative complications have been observed among Western patients. We assessed predictors of complications, morbidity, and unfavourable outcomes in a large cohort of patients with aneurysms that were treated with Neuroform Atlas stents in China. METHODS: This retrospective study included subjects who were treated with Atlas stents in China from November 2020 to January 2022. RESULTS: A total of 522 consecutive patients (mean age, 58.9 ± 9.9 years; female, 65.3% [341/522]) with 533 aneurysms were included in the study. In the early postoperative period, the neurological morbidity rate was 7.3% (38/522), the ischaemic stroke rate was 5.0% (26/522), the aneurysm rupture subarachnoid haemorrhage rate was 2.3% (12/522), and the mRS score deterioration rate was 5.4% (28/522). The mortality rate was 0.8% (4/522) in the postoperative period. The rate of neurological morbidity during the follow-up period was 1.2% (6/486). In the multifactor prediction analysis, cerebral infarction, Hunt-Hess grade (3-5), procedure duration, stent length and coil protrusion into the parent artery were found to be independent predictors of neurologic morbidity. The procedure duration, stent length and coil protrusion into the parent artery were found to be independent predictors of mRS score deterioration. CONCLUSIONS: The incidence of SCA (stent-assisted coiling)-related complications with the Atlas stent in this study population was comparable to that in Western populations. We identified the procedure duration and stent length as novel independent predictors of SCA-related ischaemic stroke, neurological morbidity, and mRS score deterioration among the Chinese population.

QTc prolongation after aneurysmal subarachnoid hemorrhage might be associated with worse neurologic outcome in patients receiving microsurgical clipping or embolization of the intracranial aneurysms: a retrospective observational study.

PURPOSE: QT interval prolongation is one of the most common electrocardiographic (ECG) abnormalities in patients with aneurysmal subarachnoid hemorrhage (aSAH). Whether corrected QT interval (QTc) prolongation is associated with perioperative cardiac events and dismal neurological outcome in mid to long-term follow-up in patients after aSAH is insufficiently studied and remains controversial. METHODS: We retrospectively studied the adult (≥ 18 years) patients admitted to our institution between Jan 2018 and Dec 2020 for aSAH who underwent intracranial aneurysm clipping or embolization. The patients were divided into 2 groups (normal and QTc prolongation groups) according to their QTc. To minimize the confounding bias, a propensity score matching (PSM) analysis was performed to compare the neurologic outcomes between patients with normal QTc and QTc prolongation. RESULTS: After screening, 908 patients were finally included. The patients were divided into 2 groups: normal QTc groups (n = 714) and long QTc group (n = 194). Female sex, hypokalemia, posterior circulation aneurysm, and higher Hunt-Hess grade were associated with QTc prolongation. In multiple regression analysis, older age, higher hemoglobin level, posterior circulation aneurysm, and higher Hunt-Hess grade were identified to be associated with worse outcome during 1-year follow-up. Before PSM, patients with QTc prolongation had higher rate of perioperative cardiac arrest or ventricular arrhythmias. After PSM, there was no statistical difference between normal and QTc prolongation groups in perioperative cardiac events. However, patients in the QTc prolongation group still had worse neurologic outcome during 1-year follow-up. CONCLUSIONS: QTc prolongation is associated with worse outcome in patients following SAH, which is independent of perioperative cardiac events.

Contrast-induced encephalopathy after an embolization procedure for a cerebral aneurysm in a female with subarachnoid hemorrhage: a case report.

BACKGROUND: Contrast-induced encephalopathy (CIE) is a rare complication during or after angiography, usually transient and reversible. CIE diagnosis is challenging due to the absence of no formal diagnostic criteria. CIE can mimic stroke symptoms, including visual disturbances, seizures, confusion, coma, and focal neurological deficits. This case reports neurological deficit reversal in a CIE patient due to the embolization of an intracranial aneurysm, the second angiographic procedure in six days. CASE PRESENTATION: A 77-year-old woman was admitted to the hospital for headaches. The cerebral computed tomography (CT) scan indicated a subarachnoid hemorrhage. The first digital subtraction angiography (DSA) identified an aneurysm of 4 mm ∗ 3 mm in size in the M1 segment of the right middle cerebral artery (MCA). Then, embolization surgery was performed for the cerebral aneurysm, which was successful. However, the patient had post-operative headaches, slurred speech, epilepsy, limb weakness, and delirium post-procedure. The non-contrast cerebral CT indicated widespread edema in the right cerebral hemisphere. The patient was diagnosed with CIE and treated with symptomatic supportive therapy. Eventually, the patient's neurological deficits and cerebral edema improved significantly. CONCLUSIONS: The current case emphasized the importance of early diagnosis and symptomatic treatment of CIE. Thus, CIE should be the first consideration during the differential diagnosis of a patient having acute neurological impairment after repeated DSA.

Study on prognosis of acutely ruptured intracranial aneurysms (SPARTA): a protocol for a multicentre prospective cohort study.

BACKGROUND: Ruptured intracranial aneurysms resulting in subarachnoid haemorrhage can be treated by open surgical or endovascular treatment. Despite multiple previous studies, uncertainties on the optimal treatment practice still exists. The resulting treatment variation may result in a variable, potentially worse, patient outcome. To better inform future treatment strategies, this study aims to identify the effectiveness of different treatment strategies in patients with ruptured intracranial aneurysms by investigating long-term functional outcome, complications and cost-effectiveness. An explorative analysis of the diagnostic and prognostic value of radiological imaging will also be performed. METHODS: This multi-centre observational prospective cohort study will have a follow-up of 10 years. A total of 880 adult patients with a subarachnoid haemorrhage caused by a ruptured intracranial aneurysm will be included. Calculation of sample size (N = 880) was performed to show non-inferiority of clip-reconstruction compared to endovascular treatment on 1 year outcome, assessed by using the ordinal modified Rankin Scale. The primary endpoint is the modified Rankin Scale score and mortality at 1 year after the initial subarachnoid haemorrhage. Patients will receive 'non-experimental' regular care during their hospital stay. For this study, health questionnaires and functional outcome will be assessed at baseline, before discharge and at follow-up visits. DISCUSSION: Despite the major healthcare and societal burden, the optimal treatment strategy for patients with subarachnoid haemorrhage caused by ruptured intracranial aneurysms is yet to be determined. Findings of this comparative effectiveness study, in which in-between centre variation in practice and patient outcome are investigated, will provide evidence on the effectiveness of treatment strategies, hopefully contributing to future high value treatment standardisation. TRIAL REGISTRATION NUMBER: NCT05851989 DATE OF REGISTRATION: May 10th, 2023.