Unruptured Cerebral Aneurysms: Evaluation and Management

The effect of aspirin on aneurysm wall enhancement: A study in rabbits and humans

ObjectiveAneurysm wall enhancement (AWE) is a potential biomarker of inflammation within the aneurysm wall that has been correlated with a higher risk of rupture. Aspirin (ASA) may decrease AWE due to its anti-inflammatory properties. We aimed to assess the effect of ASA on AWE in an animal model and a cohort of patients with unruptured intracranial aneurysms (UIAs).MethodsThree rabbits with elastase-induced aneurysms were exposed to ASA for 8 weeks and three rabbits were used as controls. 3 T high-resolution magnetic resonance imaging (HR-MRI) was performed at 7 days and 8 weeks to evaluate changes in AWE through histological and immunohistological analyses. Additionally, we evaluated AWE in patients who underwent imaging with a 3 T HR-MRI protocol. ASA exposure was defined as daily intake of 81 mg for at least six months prior to HR-MRI. AWE was quantified using three-dimensional AWE maps and histograms.ResultsAmong rabbits exposed to ASA, the mean AWE was lower at 8 weeks compared to the controls (2.11 vs 2.15, p = 0.13). Immunostaining of the aneurysm wall in rabbits that received ASA revealed a reduced expression of CD68 + or cyclooxygenase-2 + cells, compared to the controls. A total of 99 patients with 120 UIAs were included in the HR-MRI analysis of UIAs. UIAs exposed to ASA (22/120) had significantly lower median AWE than those that were not exposed (0.60 vs 0.72, p = 0.032).ConclusionASA therapy is associated with an objective reduction in AWE, suggesting a potential role in lowering the risk of aneurysm rupture.

Can β-blockers prevent intracranial aneurysm rupture?: insights from Computational Fluid Dynamics analysis

AIMS

Hypertension is a risk factor for intracranial aneurysm rupture. We analysed whether the intake of drugs from specific classes of anti-hypertensive medications affects haemodynamic parameters of intracranial aneurysm dome.

METHODS AND RESULTS

We recorded medical history including medications and the in-hospital blood pressure values. We then obtained 3D reconstruction of each patients' aneurysm dome and the feeding artery. Using OpenFOAM software, we performed Computational Fluid Dynamics analysis of blood flow through the modelled structures. Blood was modelled as Newtonian fluid, using the incompressible transient solver. As the inlet boundary condition, we used the patient-specific Internal Carotid Artery blood velocity waves obtained with Doppler ultrasound. We calculated haemodynamic parameters of the aneurysm dome. All presented analyses are cross-sectional. We included 72 patients with a total of 91 unruptured intracranial aneurysms. The history of β-blocker intake significantly influenced haemodynamic parameters of aneurysm dome. The patients on β-blockers had significantly smaller aneurysm domes (5.09 ± 2.11 mm vs. 7.41 ± 5.89 mm; P = 0.03) and did not have aneurysms larger than 10 mm (0% vs. 17.0%; P = 0.01). In the Computational Fluid Dynamics analysis, walls of aneurysms in patients who took β-blockers were characterized by lower Wall Shear Stress Gradient (1.67 ± 1.85 Pa vs. 4.3 ± 6.06 Pa; P = 0.03), Oscillatory Shear Index (0.03 ± 0.02 vs. 0.07 ± 0.10; P = 0.04), and Surface Vortex Fraction (16.2% ± 5.2% vs. 20.0% ± 6.8%; P < 0.01). After controlling for covariates, we demonstrated difference of Surface Vortex Fraction (F[1, 48] = 4.36; P = 0.04) and Oscillatory Shear Index (F[1, 48] = 6.51; P = 0.01) between patients taking and not taking β-blockers, respectively.

CONCLUSION

Intake of β-blockers might contribute to more favourable haemodynamics inside aneurysmal sac. Other anti-hypertensive medication classes were not associated with differences in intracranial aneurysm parameters.

Factors associated with ICU stays after endovascular treatments for unruptured intracranial aneurysms: A review study

BACKGROUND

For unruptured intracranial aneurysms (UIAs), conservative management is often possible. However, when direct treatment is warranted, endovascular treatments (EVTs) provide an effective minimally invasive approach. These procedures still necessitate careful patient monitoring, frequently in the Intensive Care Unit (ICU). The factors leading to ICU admission for these patients remains an area of debate.

OBJECTIVE

This systematic review aims to highlight existing literature and identify gaps in understanding the factors contributing to ICU admission following EVTs for UIAs.

METHODS

We utilized the Nested Knowledge Autolit semi-automated software to gather studies published before April 2024. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, and included studies that met predetermined population, intervention, control, and outcomes (PICO) criteria. Statistical analysis was performed using R software.

RESULTS

We retrieved 181 studies and 9 met our inclusion criteria. There was significant variability across these studies on what factors they reported. Across included studies there were 8,189 patients, with 5,620 being placed in the ICU following EVTs for UIAs. Analysis revealed that anterior aneurysm location, aneurysm-related symptoms, and procedure length were significant factors associated with ICU admission. The overall ICU admission rate was approximately 24.61 per 100 patients.

CONCLUSION

This review underscores the need for further research to understand the factors we found associated with ICU admission following EVTs for UIAs. Additional studies are needed that use a standardized approach to collect data on patient demographics, aneurysm characteristics, procedural details, and postoperative outcomes. Such studies will allow for concrete recommendations to be made on ICU needs and prognostic calculators to be developed in order to support clinical decisions and lower healthcare costs.

Determining flow stasis zones in the intracranial aneurysms and the relation between these zones and aneurysms' aspect ratios after flow diversions

BackgroundFlow diverter stents (FDSs) are widely used to treat aneurysms in the clinic. However, even the same flow diverter (FD) use on different patients' aneurysm sites can cause unexpected hemodynamics at the aneurysm region yielding low success rates for the overall treatment. Therefore, the present study aims to unfold why FDs do not work as they are supposed to for some patients and propose empirical correlation along with a contingency table analysis to estimate the flow stasis zones in the aneurysm sacs.MethodsThe present work numerically evaluated the use of FRED4518 FDS on six patients' intracranial aneurysms based on patient-specific aneurysm geometries. Computational fluid dynamics (CFD) simulation results were further processed to identify the time evolution of weightless blood particles for six patients' aneurysms.ResultsStagnation zone formation, incoming and outgoing blood flow at the aneurysm neck, and statistical analysis of six patients indicated that FRED4518 showed a large flow stasis zone for an aspect ratio larger than 0.75. However, FRED4518, used for aneurysms with an aspect ratio of less than 0.65, caused small stagnant flow zones based on the number of blood particles that stayed in the aneurysm sac.ConclusionA patient-specific empirical equation is derived considering aneurysms' morphological characteristics to determine the amount of stagnated fluid flow zones and magnitude of the mean aneurysm velocity in the aneurysm sac for FRED4518 based on weightless fluid particle results for the first time in the literature. As a result, numerical simulation results and patient data-driven equation can help perceive stagnated fluid zone amount before FRED4518 placement by shedding light on neuro-interventional surgeons and radiologists.

Presentation, management and outcomes of ruptured intracranial aneurysms in Africa: A systematic review and meta-analysis

BACKGROUND

Approximately two percent of the world's population are affected by intracranial aneurysms (IAs). This study aimed to evaluate literature regarding presentation, treatment and outcomes of ruptured IAs in Africa.

METHODS

A systematic review of the literature using PubMed/MEDLINE, SCOPUS, Web of Science and Google Scholar databases was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

RESULTS

Twenty-one retrospective studies with 1,109 patients and 11 case reports (10 countries) were included. The mean Methodological Index for Nonrandomized Studies (MINORS) for included articles was 9.1 ± 2.5. The mean age was 43.3 years (95 %CI: 37.8-48.8), with 58.4 % (342/586) female patients. WFNS/H&H grade 1 was reported in 41.2 % (98/238) of cases and Fischer grade 2 was reported in 30.4 % (98/322) of cases. CT angiography was utilized in 94.6 % (560/592, 12 articles). The ICA was reported in 24.5 % of cases (CI: 12.9 %-36.1 %). AComA and MCA were affected in 21.2 % (95 %CI: 15.2-27.2 %) and 21.3 % (95 %CI: 15.2-27.2 %) of cases, respectively. The odds of ruptured aneurysms in the anterior circulation were 14.3 (CI: 6.3-32.2). Surgical clipping was reported in 75.0 % (448/597) and coiling in 20.4 % (122/597) across 13 studies. 66.8 % (95 %CI: 57.4-76.3 %) of patients experienced neurological improvement with a mortality rate of 12.3 % (95 %CI: 7.5-17.1 %) at last follow-up.

CONCLUSION

Ruptured IAs are small and located in the anterior circulation. The lack of detailed aneurysm size reporting hampers the identification of a critical rupture size for management. More research is needed to understand aneurysm characteristics and predictors of rupture in Africa.

Silent magnetic resonance angiography diagnostic value of intracranial unruptured aneurysms

Silent magnetic resonance angiography (S-MRA) is primarily utilized to assess the blood flow in aneurysms and parent vessels of treated intracranial aneurysms. This study aimed to compare the diagnostic value of S-MRA and three-dimensional time of flight (3D-TOF) MRA for unruptured intracranial aneurysms. We included patients diagnosed with unruptured intracranial aneurysms using digital subtraction angiography (DSA) who subsequently underwent S-MRA and 3D-TOF MRA. Two independent neuroimaging and neurointerventional doctors evaluated the DSA images and measured aneurysm dimensions. Using DSA results as the gold standard, we determined the sensitivity and specificity of S-MRA and 3D-TOF MRA, as well as their accuracy in measuring aneurysm size and identifying aneurysms with daughter sacs. We detected a total of 41 intracranial aneurysms (in 37 patients) on both S-MRA and 3D-TOF MRA, with both techniques achieving a sensitivity and specificity of 100%. For aneurysm height, the intraclass correlation coefficient (ICC) was 0.977 (P < 0.001) between S-MRA and DSA, and 0.908 (P < 0.001) between 3D-TOF MRA and DSA. For neck width, the ICC was 0.663 (P < 0.001) between S-MRA and DSA, and 0.563 (P < 0.001) between 3D-TOF MRA and DSA. In terms of daughter aneurysm detection, 3D-TOF MRA Sensitivity 40%; specificity 92%: positive predictive value 100%; S-MRA sensitivity 60%; specificity 89%; positive predictive value 42%. In conclusion, S-MRA and 3D-TOF MRA did not significantly differ in aneurysm detection ability. For the detection of aneurysm with dauthger sacs indicators, the sensitivity is also higher.

Evaluation of AI-Powered Routine Screening of Clinically Acquired cMRIs for Incidental Intracranial Aneurysms

Objectives: To quantify the clinical value of integrating a commercially available artificial intelligence (AI) algorithm for intracranial aneurysm detection in a screening setting that utilizes cranial magnetic resonance imaging (cMRI) scans acquired primarily for other clinical purposes. Methods: A total of 907 consecutive cMRI datasets, including time-of-flight-angiography (TOF-MRA), were retrospectively identified from patients unaware of intracranial aneurysms. cMRIs were analyzed by a commercial AI algorithm and reassessed by consultant-level neuroradiologists, who provided confidence scores and workup recommendations for suspicious findings. Patients with newly identified findings (relative to initial cMRI reports) were contacted for on-site consultations, including cMRI follow-up or catheter angiography. The number needed to screen (NNS) was defined as the cMRI quantity that must undergo AI screening to achieve various clinical endpoints. Results: The algorithm demonstrates high sensitivities (100% for findings >4 mm in diameter), a 17.8% MRA alert rate and positive predictive values of 11.5-43.8% (depending on whether inconclusive findings are considered or not). Initial cMRI reports missed 50 out of 59 suspicious findings, including 13 certain intradural aneurysms. The NNS for additionally identifying highly suspicious and therapeutically relevant (unruptured intracranial aneurysm treatment scores balanced or in favor of treatment) findings was 152. The NNS for recommending additional follow-/workup imaging (cMRI or catheter angiography) was 26, suggesting an additional up to 4% increase in imaging procedures resulting from a preceding AI screening. Conclusions: AI-powered routine screening of cMRIs clearly lowers the high risk of incidental aneurysm non-reporting but results in a substantial burden of additional imaging follow-up for minor or inconclusive findings.

In Vivo Deformation of the Human Basilar Artery

An estimated 6.8 million people in the United States have an unruptured intracranial aneurysms, with approximately 30,000 people suffering from intracranial aneurysms rupture each year. Despite the development of population-based scores to evaluate the risk of rupture, retrospective analyses have suggested the limited usage of these scores in guiding clinical decision-making. With recent advancements in imaging technologies, artery wall motion has emerged as a promising biomarker for the general study of neurovascular mechanics and in assessing the risk of intracranial aneurysms. However, measuring arterial wall deformations in vivo itself poses several challenges, including how to image local wall motion and deriving the anisotropic wall strains over the cardiac cycle. To overcome these difficulties, we first developed a novel in vivo MRI-based imaging method to acquire cardiac gated images of the human basilar artery (BA) over the cardiac cycle. Next, complete BA endoluminal surfaces from each frame were segmented, producing high-resolution point clouds of the endoluminal surfaces. From these point clouds we developed a novel B-spline-based surface representation, then exploited the local support nature of B-splines to determine the local endoluminal surface strains. Results indicated distinct regional and temporal variations in BA wall deformation, highlighting the heterogeneous nature BA function. These included large circumferential strains (up to ∼ 20 % ), and small longitudinal strains, which were often contractile and out of phase with the circumferential strains patterns. Of particular interest was the temporal phase lag in the maximum circumferential perimeter length, which indicated that the BA deforms asynchronously over the cardiac cycle. In summary, the proposed method enabled local deformation analysis, allowing for the successful reproduction of local features of the BA, such as regional principal stretches, areal changes, and pulsatile motion. Integrating the proposed method into existing population-based scores has the potential to improve our understanding of mechanical properties of human BA and enhance clinical decision-making.

Congenital and acquired anomalies of the basilar artery: A pictorial essay

INTRODUCTION

The basilar artery is one of the two cases in our body where an arterial vessel is formed by the union of two others - the vertebral arteries. It provides vascular supply to essential structures for the main vital functions; the posterior cerebral arteries originate from it as terminal branches, and form part of the anastomotic circle of Willis.

IMAGING FINDINGS

Congenital and acquired anomalies of the basilar trunk are described. We provide a schematic and detailed representation of normal anatomical variants - mainly represented by the fenestrated basilar artery or the persistence of carotid-basilar anastomosis; course anomalies are also illustrated, with reference to neuro-vascular conflicts and dolichoectasia. Among congenital anomalies, this pictorial review also shows the variants of the basilar origin, such as in the case of basilar trunk arising from only one of the two vertebral arteries, and the calibre changes - which are represented by aneurysm and hypoplasia. The latter appears to be a risk factor for posterior circulation stroke, when associated with a bilateral posterior foetal variant.Among the acquired forms, this pictorial essay describes some clinical cases of dissections, non-congenital aneurysms, thrombosis and tumour with vascular encasing or compression of basilar artery.

CONCLUSION

CT angiography and MRI allow us to study the posterior intracranial circulation in detail, providing useful pre-treatment information. Therefore, knowledge of congenital or acquired anomalies of the basilar artery is essential for radiologists, neuroradiologists and neurosurgeons.

Small molecule inhibitors target multiple neuropathological signaling to exert novel neuroprotection in intracranial aneurysms

Intracranial aneurysms (IAs) represent a critical health concern due to their potential to rupture, leading to severe morbidity and mortality. Small molecule inhibitors (SMIs) have emerged as promising therapeutic candidates for managing IA progression and rupture risk. The current landscape of SMIs targets various molecular pathways implicated in IA pathogenesis, including inflammation, endothelial dysfunction, and extracellular matrix (ECM) degradation. Among the prominent therapeutic candidates discussed are statins, recognized for their multifaceted effects, anti-inflammatory properties, and enhancement of endothelial stability, which may mitigate IA progression. Matrix metalloproteinase inhibitors are also highlighted for their role in preserving ECM structural integrity, essential for preventing IA wall weakening and rupture. Furthermore, the review evaluates the efficacy of anti-inflammatory agents such as corticosteroids and cytokine inhibitors in attenuating IA growth driven by inflammatory processes. Our findings highlight the possibility of several pharmaceutical therapies that target matrix remodeling, inflammation, and other underlying processes to manage cerebral aneurysms. By precisely delivering therapeutic chemicals, such as antioxidants, gene therapy vectors, or anti-inflammatory medicines, to the aneurysm site, these SMI technologies treat the underlying pathophysiological causes while sparing healthy brain tissue. This review underscores the potential of SMIs as adjunctive or primary therapies in the comprehensive management of IAs, emphasizing the need for further clinical research to optimize their efficacy and safety in clinical practice.

Microsurgical clipping of unruptured intracranial aneurysms: Clinical and radiological outcomes

BACKGROUND AND OBJECTIVES

The prevalence of unruptured intracranial aneurysms is 1-3%. The annual rupture rate increases in patients with multiple aneurysms that presented a previous hemorrhage from another aneurysm.

OBJECTIVES

To evaluate outcomes of clipping unruptured aneurysms, comparing patients with single or multiple aneurysms clipped, describe the complications related to surgery and to identify risk factors predicting an unfavorable outcome.

MATERIALS AND METHODS

Retrospective study including patients who underwent clipping of unruptured aneurysms between 2020-2023 at our center. Occlusion rate, complications, and functional outcome were analyzed. Risk factors for poor prognosis are identified using univariate model.

RESULTS

82 patients with 114 aneurysms were treated with microsurgery. Multiple aneurysms were clipped in 22 patients. A mini-open approach was used in 86,5% of cases. Complete occlusion in angio3D was found in 78.6% of clipped aneurysms. Complication rate was 12.2%, including asymptomatic cases. Mortality was 0%. The probability of 1 point mRS worsening was 7.3% and 2 or more points was 1.2%, with a good functional outcome in 98.9%. Clipping multiple aneurysms, miniopen approaches, or surgery in patients with previous subarachnoid hemorrhage did not increase the risk of complications. Posterior circulation aneurysms surgery increased the risk of ischemia.

CONCLUSIONS

The management for unruptured intracranial aneurysms should be multimodal and based on clinical and radiological outcomes. Microsurgery is a valid and safe technique, with 0% mortality and bleeding rates and 1,2% rate of severe morbidity in our series.

Pipeline Embolization device for the treatment of unruptured intracranial saccular aneurysms: a systematic review and meta-analysis of long-term outcomes

INTRODUCTION

The pipeline embolization device (PED) is commonly used for intracranial aneurysm treatment. While its effectiveness for certain types of aneurysms is well-established, its efficacy for saccular aneurysms remains controversial. We aimed to assess the long-term outcomes of PED treatment for unruptured intracranial saccular aneurysms.

METHODS

Systematic review and meta-analysis were conducted following PRISMA guidelines. Studies with at least one year of follow-up after PED treatment for saccular aneurysms were included. The primary endpoint was angiographic aneurysm occlusion at long-term follow-up (≥ 12 months), and the secondary outcome was long-term complications. We conducted a meta-regression analysis to explore potential sources of heterogeneity across studies.

RESULTS

Eleven studies of 797 patients with 963 aneurysms were included. Long-term angiographic occlusion rate was 85% (95% CI, 77-91%; p < 0.01), symptomatic ischemic stroke rate was 1% (95% CI, 0-3%; p < 0.01), rupture rate was 1% (95% CI, 0-2%; p = 0.02), and intracranial hemorrhage (ICH) rate was 0.2% (95% CI, 0-1%; p = 0.11). Meta-regression analysis revealed a non-significant decreasing trend per year for aneurysmal occlusion, ischemic stroke rate, delayed aneurysmal rupture, and ICH.

CONCLUSION

PED demonstrates high long-term occlusion and low complication rates, suggesting it is a safe and effective treatment option for saccular aneurysms. Additionally, newer devices exhibit reduced thrombogenic profiles and safety with decreasing trends in ICH, ischemic stroke, and delayed aneurysmal rupture.

Racial and socioeconomic disparities in the treatment of unruptured intracranial aneurysms: A county hospital experience

BACKGROUND

With increasing prevalence of unruptured intracranial aneurysms (UIAs), there is a need to provide appropriate management. Several studies have suggested that minorities in the United States have limited access to non-invasive imaging leading to increased presentation of aneurysmal subarachnoid hemorrhages (aSAHs). Given our medical institution's commitment to ensuring racial equality within our health care system, we chose to analyze our practice to assess the utilization of care provided by our neuroendovascular team. We hypothesized that given our diverse neuroendovascular care team along with our dedication to equity in healthcare, that we would find no difference in care provided to minority patients versus white patients who presented with UIAs.

METHODS

We conducted a retrospective electronic medical record-based review of all patients with UIAs (n = 140) between September 2010 and June 2022 treated at a county hospital. Data regarding age at the time of treatment, gender, race, insurance type and aneurysm location were obtained.

RESULTS

Of the 140 patients that underwent treatment, 54 % of patients were from the Black/Hispanic group and 46 % were from the white/non-Hispanic group. Commercial/private insurance was more common among White/NonHispanic patients (57.7 % vs 51.4 %) whereas Medicaid or uninsured status was more common among Black/Hispanic patients (25.7 % vs 15.4 %), although these differences were not statistically significant.

CONCLUSION

Building a diverse neuroendovascular physician team with intentionality to equity in healthcare, and providing appropriate funding and resources to facilities used by marginalized populations, such as safety-net institutions, can mitigate minority patients' limited access to intracranial aneurysmal care.

How AI and Robotics Will Advance Interventional Radiology: Narrative Review and Future Perspectives

The rapid advancement of artificial intelligence (AI) and robotics has led to significant progress in various medical fields including interventional radiology (IR). This review focuses on the research progress and applications of AI and robotics in IR, including deep learning (DL), machine learning (ML), and convolutional neural networks (CNNs) across specialties such as oncology, neurology, and cardiology, aiming to explore potential directions in future interventional treatments. To ensure the breadth and depth of this review, we implemented a systematic literature search strategy, selecting research published within the last five years. We conducted searches in databases such as PubMed and Google Scholar to find relevant literature. Special emphasis was placed on selecting large-scale studies to ensure the comprehensiveness and reliability of the results. This review summarizes the latest research directions and developments, ultimately analyzing their corresponding potential and limitations. It furnishes essential information and insights for researchers, clinicians, and policymakers, potentially propelling advancements and innovations within the domains of AI and IR. Finally, our findings indicate that although AI and robotics technologies are not yet widely applied in clinical settings, they are evolving across multiple aspects and are expected to significantly improve the processes and efficacy of interventional treatments.

Pharmaceutical Modulation of Intracranial Aneurysm Development and Rupture

Management of intracranial aneurysms (IAs) is determined by patient age, risk of rupture, and comorbid conditions. While endovascular and microsurgical interventions offer solutions to mitigate the risk of rupture, pharmacological management strategies may complement these approaches or serve as alternatives in appropriate cases. The pathophysiology of IAs allows for the targeting of inflammation to prevent the development and rupture of IAs. The aim of this review is to provide an updated summary of different pharmaceutical management strategies for IAs. Acetylsalicylic acid and renin-angiotensin-aldosterone system (RAAS) inhibitor antihypertensives have some evidence supporting their protective effect. Studies of selective cyclooxygenase-2 (COX-2) inhibitors, statins, ADP inhibitors, and other metabolism-affecting drugs have demonstrated inconclusive findings regarding their association with aneurysm growth or rupture. In this manuscript, we highlight the evidence supporting each drug's effectiveness.

A 5-Year Follow-Up after Endovascular Treatment of 402 Intracranial Aneurysms-A Single-Centre Experience

The aim of our study was to evaluate the early and long-term clinical and morphological outcomes of the endovascular treatment of ruptured and non-ruptured intracranial aneurysms in a cohort of patients from a single centre. We retrospectively analysed the treatment outcomes of 402 endovascularly treated intracranial aneurysms with an average follow-up of 5.5 years. All included patients were treated with endovascular techniques (coil, stent or both). We analysed patient demographics, risk factors for an aneurysm rupture, aneurysm characteristics, and clinical and angiographic complications and outcomes. We analysed and compared the data from the two groups, ruptured aneurysms (RAs) and unruptured aneurysms (UAs), separately. Out of the 318 patients included, a good early clinical outcome was achieved in 78.5% of RAs and in 95.3% of UAs. No complications occurred in 87.71% of patients with UAs and in 80.45% with RAs. The periprocedural rupture rate for UAs and RAs was 0.8% and 2.2%, respectively. The rate of thromboembolic events was 4.8 and 8% for UAs and RAs, respectively. A retreatment due to the recanalisation was required in 9.21% of patients with UAs and in 16.66% of patients with RAs. The results from our centre showed an overall favourable clinical outcome with acceptable periprocedural complications for both RAs and UR aneurysms and proved the endovascular method as safe and effective in the treatment of intracranial aneurysms.

Exploring the Landscape of Intracranial Aneurysms in South America: A Comprehensive Narrative Review Intracranial Aneurysms in South America

Exploring the landscape of intracranial aneurysms in South America unravels a complex interplay of epidemiological factors, clinical manifestations, and therapeutic challenges. The study methodically conducts a comprehensive literature review spanning the years 2003 to 2023, focusing on English-language articles obtained from diverse databases to elucidate the multifaceted nature of intracranial aneurysms in the region. Results and discussions categorize outcomes into positive domains, emphasizing successful treatments, favorable recoveries, and high survival rates, while also shedding light on negative aspects such as residual aneurysms and complications. The research illuminates significant gaps in pathological typing of intracranial aneurysms and exposes challenges in healthcare accessibility, notably the disparities in neurosurgical resources. Management challenges, including constrained infrastructure access, a neurosurgeon shortage, and gender disparities, are underscored. Transitioning to future prospects, the study advocates for strategic interventions, proposing expanded neurosurgical training, multidisciplinary approaches, improved funding, enhanced access to care, and fostering international collaborations. The study concludes by emphasizing the pivotal role of collaborative efforts, intensified training programs, and global partnerships in propelling intracranial aneurysm management forward in South America, ultimately contributing to enhanced patient outcomes across the region.

Evaluation of effectiveness and safety of the CorPath GRX robotic system in endovascular embolization procedures of cerebral aneurysms

BACKGROUND

Robotic-assisted neurointervention was recently introduced, with implications that it could be used to treat neurovascular diseases.

OBJECTIVE

To evaluate the effectiveness and safety of the robotic-assisted platform CorPath GRX for treating cerebral aneurysms.

METHODS

This prospective, international, multicenter study enrolled patients with brain aneurysms that required endovascular coiling and/or stent-assisted coiling. The primary effectiveness endpoint was defined as successful completion of the robotic-assisted endovascular procedure without any unplanned conversion to manual treatment with guidewire or microcatheter navigation, embolization coil(s) or intracranial stent(s) deployment, or an inability to navigate vessel anatomy. The primary safety endpoint included intraprocedural and periprocedural events.

RESULTS

The study enrolled 117 patients (74.4% female) with mean age of 56.6 years from 10 international sites,. Headache was the most common presenting symptom in 40/117 (34.2%) subjects. Internal carotid artery was the most common location (34/122, 27.9%), and the mean aneurysm height and neck width were 5.7±2.6 mm and 3.5±1.4 mm, respectively. The overall procedure time was 117.3±47.3 min with 59.4±32.6 min robotic procedure time. Primary effectiveness was achieved in 110/117 (94%) subjects with seven subjects requiring conversion to manual for procedure completion. Only four primary safety events were recorded with two intraprocedural aneurysm ruptures and two strokes. A Raymond-Roy Classification Scale score of 1 was achieved in 71/110 (64.5%) subjects, and all subjects were discharged with a modified Rankin Scale score of ≤2.

CONCLUSIONS

This first-of-its-kind robotic-assisted neurovascular trial demonstrates the effectiveness and safety of the CorPath GRX System for endovascular embolization of cerebral aneurysm procedures.

TRIAL REGISTRATION NUMBER

NCT04236856.

ADORA3: A Key Player in the Pathogenesis of Intracranial Aneurysms and a Potential Diagnostic Biomarker

BACKGROUND

The effects of genes on the development of intracranial aneurysms (IAs) remain to be elucidated, and reliable blood biomarkers for diagnosing IAs are yet to be established. This study aimed to identify genes associated with IAs pathogenesis and explore their diagnostic value by analyzing IAs datasets, conducting vascular smooth muscle cells (VSMC) experiments, and performing blood detection.

METHODS

IAs datasets were collected and the differentially expressed genes were analyzed. The selected genes were validated in external datasets. Autophagy was induced in VSMC and the effect of selected genes was determined. The diagnostic value of selected gene on the IAs were explored using area under curve (AUC) analysis using IAs plasma samples.

RESULTS

Analysis of 61 samples (32 controls and 29 IAs tissues) revealed a significant increase in expression of ADORA3 compared with normal tissues using empirical Bayes methods of "limma" package; this was further validated by two external datasets. Additionally, induction of autophagy in VSMC lead to upregulation of ADORA3. Conversely, silencing ADORA3 suppressed VSMC proliferation and autophagy. Furthermore, analysis of an IAs blood sample dataset and clinical plasma samples demonstrated increased ADORA3 expression in patients with IA compared with normal subjects. The diagnostic value of blood ADORA3 expression in IAs was moderate when analyzing clinical samples (AUC: 0.756). Combining ADORA3 with IL2RB or CCR7 further enhanced the diagnostic ability for IAs, with the AUC value over 0.83.

CONCLUSIONS

High expression of ADORA3 is associated with IAs pathogenesis, likely through its promotion of VSMC autophagy. Furthermore, blood ADORA3 levels have the potential to serve as an auxiliary diagnostic biomarker for IAs.

A Study on the Efficacy and Safety of Pipeline Shield Stents and Nonmodified Surface Flow-Diverting Stents in Patients with Intracranial Aneurysms

BACKGROUND

Few studies have compared the Pipeline Shield stents with previous generations of flow-diverting stents (FDSs) for the treatment of unruptured intracranial aneurysms. This study aimed to evaluate the efficacy and safety of Pipeline Shield stents and FDSs without modified surfaces.

METHODS

The present evaluation is a retrospective cohort study of patients endovascularly treated with Pipeline Shield stents or FDSs without modified surfaces for unruptured intracranial aneurysms between January 2014 and June 2022. The data analyzed were obtained from the anonymized database of our institution's interventional radiology service.

RESULTS

A total of 147 patients with 155 unruptured intracranial aneurysms were included. Of the 155 aneurysms, 96 were treated with Pipeline Shield stents and 59 with FDSs without modified surfaces. The aneurysms treated with Pipeline Shield stents had higher 6-month (O'Kelly-Marotta [OKM] D; 87.5% vs. 71.4%; P = 0.025) and 1-year (OKM D; 82.5% vs. 63.0%; P = 0.047) occlusion rates than the aneurysms treated using FDSs without modified surfaces. No differences between the devices were found at the 1-year follow-up in the incidence of ischemic stroke (P = 0.939) or hemorrhagic complications (P = 0.559).

CONCLUSIONS

Pipeline Shield stents demonstrated superior complete occlusion rates (OKM D) at both the 6-month and the 1-year follow-up assessments compared with nonmodified surface FDSs. No significant differences were found in the safety profiles between the 2 types of stents with regard to thromboembolic complications and ischemic events. Further research with larger study populations is necessary to validate these findings.

Review Article Imaging Evaluation for the Size of Saccular Intracranial Aneurysm

BACKGROUND

In addition to evaluate the morphologic characteristics of intracranial aneurysms, the dimension of the aneurysm is an important parameter for selecting treatment strategies, determining follow-up period, and predicting the risk of rupture. High-resolution vessel wall imaging has an increasingly dominant role in measuring aneurysm size and assessing the risk of rupture accurately. The size of saccular intracranial aneurysm may play an important role as a predictor of the rupture risk. With the rapid improvement in radiological techniques, different noninvasive imaging methods have respective characteristics in saccular intracranial aneurysms (sIA) measurement and morphologic description. Although most studies believe that the larger the aneurysm, the higher the risk of rupture, there is still a synergistic effect of multiple factors (such as location, morphology, history of aneurysmal subarachnoid hemorrhage, and even patient factors) to explain the rupture of small aneurysms.

METHODS

A literature search was performed of intracranial aneurysm size and risk of rupture.

RESULTS

The specificity and sensitivity of different imaging methods for evaluating intracranial aneurysms varied based on sizes. Rupture risk of aneurysms was associated with multiple factors. A comprehensive assessment that considered aneurysm size in conjunction with other relevant factors would be helpful in guiding options of management.

CONCLUSIONS

Accurate measurement of the dimension of sIA is an important basis in the selection of appropriate treatment including intravascular intervention or surgical clipping, as well as for determining the follow-up cycles for conservative or postoperative treatment. A uniform definition of sIA size is recommended to facilitate the integration of similar studies and to accomplish rapid and effective screening of cases in sIA treatment.

Circular RNAs in intracranial aneurysms: Emerging roles in pathogenesis, diagnosis and therapeutic intervention

Intracranial aneurysms (IAs) present a substantial health threat, given the potential for catastrophic ruptures and subarachnoid hemorrhages (SAH). Swift and effective measures for diagnosis and treatment are paramount to enhance patient outcomes and alleviate the associated healthcare burden. In this context, circular RNAs (circRNAs) have emerged as an intriguing area of investigation, offering promise as both diagnostic biomarkers and therapeutic targets for IAs. CircRNAs have demonstrated their influence on critical molecular and cellular processes underpinning IAs pathogenesis, revealing their pivotal role in understanding this complex ailment. Beyond their diagnostic potential, circRNAs hold great potential as prognostic markers, providing crucial insights into IAs rupture risk. The unique circular structure and their regulatory functions make circRNAs an enticing avenue for innovative therapeutic approaches. The ongoing study of circRNAs in the context of IAs is an exciting and rapidly evolving field that has the potential to revolutionize approaches to diagnosis, treatment, and prevention of this life-threatening condition. As research continues to unravel the intricate roles of circRNAs, they are poised to become invaluable tools in clinical practice, enhancing patient care and ultimately reducing the impact of cerebral aneurysms on both individuals and healthcare systems. This comprehensive review delves deeply into the world of circRNAs in the realm of IAs, elucidating their multifaceted roles in the onset and progression of this condition. Moreover, this review ventures into the diagnosis and therapeutic potential of circRNAs, exploring their possible applications in gene therapy and as targets for novel treatment modalities.

Prediction of cerebral aneurysm rupture risk by machine learning algorithms: a systematic review and meta-analysis of 18,670 participants

It is possible to identify unruptured intracranial aneurysms (UIA) using machine learning (ML) algorithms, which can be a life-saving strategy, especially in high-risk populations. To better understand the importance and effectiveness of ML algorithms in practice, a systematic review and meta-analysis were conducted to predict cerebral aneurysm rupture risk. PubMed, Scopus, Web of Science, and Embase were searched without restrictions until March 20, 2023. Eligibility criteria included studies that used ML approaches in patients with cerebral aneurysms confirmed by DSA, CTA, or MRI. Out of 35 studies included, 33 were cohort, and 11 used digital subtraction angiography (DSA) as their reference imaging modality. Middle cerebral artery (MCA) and anterior cerebral artery (ACA) were the commonest locations of aneurysmal vascular involvement-51% and 40%, respectively. The aneurysm morphology was saccular in 48% of studies. Ten of 37 studies (27%) used deep learning techniques such as CNNs and ANNs. Meta-analysis was performed on 17 studies: sensitivity of 0.83 (95% confidence interval (CI), 0.77-0.88); specificity of 0.83 (95% CI, 0.75-0.88); positive DLR of 4.81 (95% CI, 3.29-7.02) and the negative DLR of 0.20 (95% CI, 0.14-0.29); a diagnostic score of 3.17 (95% CI, 2.55-3.78); odds ratio of 23.69 (95% CI, 12.75-44.01). ML algorithms can effectively predict the risk of rupture in cerebral aneurysms with good levels of accuracy, sensitivity, and specificity. However, further research is needed to enhance their diagnostic performance in predicting the rupture status of IA.

Aberrant expression and regulatory role of histone deacetylase 9 in vascular endothelial cell injury in intracranial aneurysm

Intracranial aneurysm (IA) is one of the most challenging cerebrovascular lesions for clinicians. The aim of this study was to investigate the abnormal expression and role of histone deacetylase 9 (HDAC9) in IA-associated injury of vascular endothelial cells (VECs). First, IA tissue and normal arterial tissue were collected and VECs were isolated from IA patients. The expression levels of HDAC9, microRNA (miR)-34a-5p, and vascular endothelial growth factor-A (VEGFA) were determined. Cell viability, proliferation, apoptosis, and migration were assessed by Cell Counting Kit-8 (CCK-8) assay, EdU staining, TUNEL staining, and transwell assay. The binding of miR-34a-5p to VEGFA was analyzed by the dual-luciferase assay, and the accumulation of HDAC9 and lysine histone acetylation at H3 (H3K9, H3K14, and H3K18) on the miR-34a-5p promoter was detected by the chromatin immunoprecipitation assay. The results showed that HDAC9 and VEGFA were increased and miR-34a-5p was decreased in IA tissues and cells. Silencing of HDAC9 inhibited apoptosis and increased viability, proliferation, and migration of VECs, whereas overexpression of HDAC9 exerted the opposite functions. HDAC9 accumulated at the miR-34a-5p promoter to decrease miR-34a-5p expression by reducing H3 locus-specific acetylation and further promoted VEGFA expression. Knockdown of miR-34a-5p or VEGFA overexpression reversed the protective role of HDAC9 silencing in VECs injury. In conclusion, our study suggests that HDAC9 may be a therapeutic target for IA.

Multimodal exploration of the intracranial aneurysm wall

PURPOSE

Intracranial aneurysms (IAs) are pathological changes of the intracranial vessel wall, although clinical image data can only show the vessel lumen. Histology can provide wall information but is typically restricted to ex vivo 2D slices where the shape of the tissue is altered.

METHODS

We developed a visual exploration pipeline for a comprehensive view of an IA. We extract multimodal information (like stain classification and segmentation of histologic images) and combine them via 2D to 3D mapping and virtual inflation of deformed tissue. Histological data, including four stains, micro-CT data and segmented calcifications as well as hemodynamic information like wall shear stress (WSS), are combined with the 3D model of the resected aneurysm.

RESULTS

Calcifications were mostly present in the tissue part with increased WSS. In the 3D model, an area of increased wall thickness was identified and correlated to histology, where the Oil red O (ORO) stained images showed a lipid accumulation and the alpha-smooth muscle actin (aSMA) stained images showed a slight loss of muscle cells.

CONCLUSION

Our visual exploration pipeline combines multimodal information about the aneurysm wall to improve the understanding of wall changes and IA development. The user can identify regions and correlate how hemodynamic forces, e.g. WSS, are reflected by histological structures of the vessel wall, wall thickness and calcifications.

Correlation between the rate of morphological changes and rupture of intracranial aneurysms during one cardiac cycle analyzed by 4D-CTA

Objective

This study aimed to analyze the relationship between the rate of morphological changes and intracranial aneurysm rupture during the cardiac cycle.

Methods

Eighty-four patients with intracranial aneurysms were retrospectively analyzed and divided into the rupture (42 cases) and unruptured (42 cases) groups. Four-dimensional computed tomography angiography (4D-CTA) was performed to collect quantitative parameters of aneurysm morphology and calculate the morphological change rate. The potential factors associated with aneurysm rupture were determined by comparing the general clinical data and rate of change in the location and morphology of the aneurysm between the two groups.

Results

Each morphological change rate in the rupture group was generally higher than that of the unruptured group. The rate of dome height change and aneurysm volume change were independent factors associated with aneurysm rupture. ROC curve analysis revealed that the diagnostic accuracy of the aneurysm volume change rate was higher. When the volume change rate was 12.33%, the sensitivity and specificity of rupture were 90.5 and 55.8%, respectively.

Conclusion

The rate of change in dome height and volume of intracranial aneurysms during one cardiac cycle were independent factors associated with aneurysm rupture.

Comparison of 1.5 T and 3 T magnetic resonance angiography for detecting cerebral aneurysms using deep learning-based computer-assisted detection software

PURPOSE

To compare the diagnostic performance of 1.5 T versus 3 T magnetic resonance angiography (MRA) for detecting cerebral aneurysms with clinically available deep learning-based computer-assisted detection software (EIRL aneurysm® [EIRL_an]), which has been approved by the Japanese Pharmaceuticals and Medical Devices Agency. We also sought to analyze the causes of potential false positives.

METHODS

In this single-center, retrospective study, we evaluated the MRA scans of 90 patients who underwent head MRA (1.5 T and 3 T in 45 patients each) in clinical practice. Overall, 51 patients had 70 aneurysms. We used MRI from a vendor not included in the dataset used to create the EIRL_an algorithm. Two radiologists determined the ground truth, the accuracy of the candidates noted by EIRL_an, and the causes of false positives. The sensitivity, number of false positives per case (FPs/case), and the causes of false positives were compared between 1.5 T and 3 T MRA. Pearson's χ2 test, Fisher's exact test, and the Mann‒Whitney U test were used for the statistical analyses as appropriate.

RESULTS

The sensitivity was high for 1.5 T and 3 T MRA (0.875‒1), but the number of FPs/case was significantly higher with 3 T MRA (1.511 vs. 2.578, p < 0.001). The most common causes of false positives (descending order) were the origin/bifurcation of vessels/branches, flow-related artifacts, and atherosclerosis and were similar between 1.5 T and 3 T MRA.

CONCLUSION

EIRL_an detected significantly more false-positive lesions with 3 T than with 1.5 T MRA in this external validation study. Our data may help physicians with limited experience with MRA to correctly diagnose aneurysms using EIRL_an.

Posterior Communicating Artery Aneurysm With Referred Tooth Pain: A Case Report

Oculomotor nerve (CN III) palsy (ONP) has multiple etiologies, with aneurysms and ischemic injury being the two leading causes. The presentations of these conditions differ, as aneurysms commonly manifest with pupillary involvement, while ischemic-related ONP often leads to a pupil-sparing presentation. We present a 63-year-old African American male with a history of sickle cell trait, ocular sickle cell disease, and untreated hypertension that develops "down and out" left eye with a mid-dilated pupil unresponsive to light. However, the patient developed severe left upper tooth pain after the onset of the eye pain, which progressed to ONP. The patient's dental and radiographic evaluation did not indicate any obvious source for his tooth pain. Magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) of the head revealed a 7-mm saccular aneurysm with a 2-mm neck arising from the left posterior communicating artery (PCOM) aneurysm, and neurovascular surgical intervention was initiated. This case highlights the potential of referred tooth pain as an early symptom in patients with PCOM aneurysm, which physicians should be vigilant about and consider as a potential indicator of the condition. Therefore, collaboration between different specialties, including ophthalmology, neurology, neurosurgery, and dental care, is necessary to formulate a comprehensive treatment plan that effectively addresses the patient's specific needs and challenges.

Intracranial aneurysms in Ghanaian adults

Objective

To document the location, size, and multiplicity of intracranial aneurysms in Ghanaians who have undergone digital subtraction angiography (DSA) at a single centre in Accra, Ghana.

Design

We conducted a retrospective observational review of the medical records of all patients diagnosed with intracranial aneurysms on DSA.

Setting

Patients' medical records at Euracare Advanced Diagnostic and Heart Centre were reviewed between March 2018 and March 2020.

Participants

Thirty-one patients were identified with various intracranial aneurysms (IAs) within the study period. Patients' ages, sex, and types of IAs were extracted using a checklist and analysed using Microsoft Excel for Windows 2016.

Interventions

None.

Main outcome measures

The prevalence of types and distribution of intracranial aneurysms.

Results

The age range of the patients was 26-76 years, with a mean age of 45.5±14.3 years. The mean age of men and women with IA was 45.5 ±15.9 years and 46.7 51.3±12.9 years, respectively. The most common IAs were located in the posterior communicating artery (PCOM) at 54.8% (95%CI: 36.0, 72.7), followed by the anterior communicating (ACOM), which constituted 32.3% (95%CI: 16.7, 51.4). The majority, 89.2% (33/37) of these aneurysms were less than 7mm in diameter. Single aneurysms were present in 25 (80.6%).

Conclusion

The most common IAs were found in the PCOM and ACOM, and IAs tend to rupture at a younger age and smaller size among the Ghanaian adults examined. Early detection and treatment of IAs less than 7mm in diameter is recommended.

Funding

None declared.

FSTIF-UNet: A Deep Learning-Based Method Towards Automatic Segmentation of Intracranial Aneurysms in Un-Reconstructed 3D-RA

Segmentation of intracranial aneurysms (IAs) is an important step for the diagnosis and treatment of IAs. However, the process by which clinicians manually recognize and localize IAs is overly labor intensive. This study aims to develop a deep-learning-based framework (defined as FSTIF-UNet) towards IAs segmentation in un-reconstructed 3D Rotational Angiography (3D-RA) images. 3D-RA sequences from 300 patients with IAs from Beijing Tiantan Hospital are enrolled. Inspired by radiologists' clincial skills, a Skip-Review attention mechanism is proposed to repeatedly fuse the long-term spatiotemporal features of several images with the most obvious IA's features (sellected by a pre-detection network). Then, a Conv-LSTM is used to fuse the short-term spatiotemporal features of the selected 15 3D-RA images from the equally-spaced viewing angles. The combination of the two modules realizes the full-scale spatiotemporal information fusion of the 3D-RA sequence. FSTIF-UNet achieves DSC, IoU, Sens, Haus, and F1-Score of 0.9109, 0.8586, 0.9314, 1.358 and 0.8883, respectively, and time taken for network segmentation is 0.89 s/case. The results show significant improvement in IA segmentation performance with FSTIF-UNet compared with baseline networks (with DSC from 0.8486 - 0.8794). The proposed FSTIF-UNet establishes a practical method to assist the radiologists in clinical diagnosis.

Interobserver reliability of computed tomography angiography in the assessment of ruptured intracranial aneurysm and impact on patient management

BACKGROUND

Aneurysmal subarachnoid hemorrhage is an emergency that can lead to a high mortality rate and many severe complications. It is critical to make a rapid radiological evaluation of ruptured intracranial aneurysms (RIAs) to determine the appropriate surgical treatment.

AIM

To assess the reliability of computed tomography angiography (CTA) in assessing different features of ruptured intracranial aneurysm and its impact on patient management.

METHODS

The final cohort of this study consisted of 146 patients with RIAs (75 male and 71 female) who underwent cerebral CTA. Their age ranged from 25 to 80, and the mean age ± SD was 57 ± 8.95 years. Two readers were asked to assess different features related to the aneurysm and perianeurysmal environment. Inter-observer agreement was measured using kappa statistics. Imaging data extracted from non-contrast computed tomography and CTA were considered to categorize the study population into two groups according to the recommended therapeutic approach.

RESULTS

The inter-observer agreement of both reviewers was excellent for the detection of aneurysms (K = 0.95, P = 0.001), aneurysm location (K = 0.98, P = 0.001), and (K = 0.98, P = 0.001), morphology (K = 0.92, P = 0.001) and margins (K = 0.95, P = 0.001). There was an excellent interobserver agreement for the measurement of aneurysm size (K = 0.89, P = 0.001), neck (K = 0.85, P = 0.001), and dome-to-neck ratio (K = 0.98, P = 0.001). There was an excellent inter-observer agreement for the detection of other aneurysm-related features such as thrombosis (K = 0.82, P = 0.001), calcification (K = 1.0, P = 0.001), bony landmark (K = 0.89, P = 0.001) and branch incorporation (K = 0.91, P = 0.001) as well as perianeurysmal findings including vasospasm (K = 0.91, P = 0.001), perianeurysmal cyst (K = 1.0, P = 0.001) and associated vascular lesions (K = 0.83, P = 0.001). Based on imaging features, 87 patients were recommended to have endovascular treatment, while surgery was recommended in 59 patients. 71.2% of the study population underwent the recommended therapy.

CONCLUSION

CTA is a reproducible promising diagnostic imaging modality for detecting and characterizing cerebral aneurysms.

A review of the top 100 most influential articles on basilar artery aneurysms

Basilar artery aneurysms account for approximately 5% of all intracranial aneurysms. This bibliometric analysis summarizes the most-cited articles on basilar artery aneurysms and highlights the contributing articles to today's evidence-based practice. In the execution of this bibliometric-based review article, the Scopus database was used to perform a title-specific, keyword-based search for all publications until August 2022. The keyword "basilar artery aneurysm" or "basilar aneurysm" was used. Our results were arranged in descending order based on the article's citation count. The 100 most cited articles were selected for analysis. Parameters included the following: title, citation count, citations per year, authors, specialty of first author, institution, country of origin, publishing journal, Source Normalized Impact Per Paper (SNIP), and Hirsch index. The keyword-based search showed that 699 articles were published between 1888 and 2022. The top 100 articles were published between 1961 and 2019. The top 100 most cited articles collected a total of 8869 citations with an average of 89 citations per paper. The rate of self-citations accounted for an average of 4.85% of the total number of citations. The bibliometric analysis provides a quantitative overview of how medical topics and interventions are analyzed in academic medicine. In the present study, we evaluated the global trends in basilar artery aneurysms by finding the top 100 most cited papers.

Endothelial nitric oxide synthase rs1799983 gene polymorphism is associated with the risk of developing intracranial aneurysm

PURPOSE

The intracranial aneurysm (IA) rupture is associated with a subarachnoid hemorrhage. One third of patients die, and one third remain depend for daily activities. Genetic factors are crucial in the formation and clinical evolution of IAs. Multiple loci have been associated with AIs, much of them implicating multiple pathways related to vascular endothelial maintenance and extracellular matrix integrity. Thus, the aim of our study was to characterize whether polymorphisms in genes implicated in the vascular endothelial maintenance could modify the risk of developing IAs.

SUBJECTS AND METHODS

We have studied 176 patients with IA recruited in the Service of Neurosurgery at the University Hospital of Valladolid (Spain) and a control group if 150 sex-matched healthy subjects. Clinical variables were collected from each patient. We have analyzed VEGFA rs833061, VEGFR2 rs2071559, endothelin rs5370, endoglin rs3739817, and eNOS rs1799983 polymorphisms.

RESULTS

Our results showed that allele T of the eNOS rs1799983 polymorphism is correlated with decreased risk of developing the disease; thus, allele G of the eNOS rs1799983 polymorphism increased the risk of developing IA.

CONCLUSION

The association of eNOS rs1799983 polymorphism with the risk to suffer IA reinforces the hypothesis that genetic variants in eNOS gene could be crucial in the pathogenesis of IA.

Torque Teno virus DNA is found in the intracranial aneurysm wall-Is there a causative role?

Objective

Torque Teno virus (TTV) is a recently discovered virus with high prevalence worldwide, that has been associated with vascular diseases. The aim of this study is to investigate the prevalence of TTV molecular DNA in the intracranial aneurysm (IA) artery walls.

Method

Samples of IA walls were collected after microsurgical clipping from 35 patients with IA (22 ruptured/13 unruptured cases). The samples were submitted to molecular DNA extraction using the EasyMag automatized extractor and performed with Qiagen DNA extraction Minikit 250. The samples underwent PCR examination with primers for β-globin as internal control using the Nanodrop ^® 2000 spectrophotometer. A quantitative (real-time) PCR with TTV-specific primers was performed. Clinical and radiological data of patients included was collected.

Results

TTV was detected in 15 (42.85%) cases, being 10 (45.4%) ruptured and 5 (38.4%) unruptured (p = 0.732) lesions. Multiple IAs accounted for 14 (40%) cases. Five cases (17.2%) had TTV+ and multiple aneurysms (p = 0.73). Association between presence of virus and aneurysm rupture was not statistically significant (p = 0.96).

Conclusion

This study demonstrated a relatively high prevalence of viral DNA in the walls of IAs. This is the first study to identify the presence of TTV DNA in IA's samples, which was found more often in ruptured lesions. This is an exploratory study, therefore, larger studies are required to clarify the relationships between inflammation, viral infection, IA formation and rupture.

Reproducibility of the computational fluid dynamic analysis of a cerebral aneurysm monitored over a decade

Computational fluid dynamics (CFD) simulations are increasingly utilised to evaluate intracranial aneurysm (IA) haemodynamics to aid in the prediction of morphological changes and rupture risk. However, these models vary and differences in published results warrant the investigation of IA-CFD reproducibility. This study aims to explore sources of intra-team variability and determine its impact on the aneurysm morphology and CFD parameters. A team of four operators were given six sets of magnetic resonance angiography data spanning a decade from one patient with a middle cerebral aneurysm. All operators were given the same protocol and software for model reconstruction and numerical analysis. The morphology and haemodynamics of the operator models were then compared. The segmentation, smoothing factor, inlet and outflow branch lengths were found to cause intra-team variability. There was 80% reproducibility in the time-averaged wall shear stress distribution among operators with the major difference attributed to the level of smoothing. Based on these findings, it was concluded that the clinical applicability of CFD simulations may be feasible if a standardised segmentation protocol is developed. Moreover, when analysing the aneurysm shape change over a decade, it was noted that the co-existence of positive and negative values of the wall shear stress divergence (WSSD) contributed to the growth of a daughter sac.

Advanced cross-sectional imaging of cerebral aneurysms

While the rupture rate of cerebral aneurysms is only 1% per year, ruptured aneurysms are associated with significant morbidity and mortality, while aneurysm treatments have their own associated risk of morbidity and mortality. Conventional markers for aneurysm rupture include patient-specific and aneurysm-specific characteristics, with the development of scoring systems to better assess rupture risk. These scores, however, rely heavily on aneurysm size, and their accuracy in assessing risk in smaller aneurysms is limited. While the individual risk of rupture of small aneurysms is low, due to their sheer number, the largest proportion of ruptured aneurysms are small aneurysms. Conventional imaging techniques are valuable in characterizing aneurysm morphology; however, advanced imaging techniques assessing the presence of inflammatory changes within the aneurysm wall, hemodynamic characteristics of blood flow within aneurysm sacs, and imaging visualization of irregular aneurysm wall motion have been used to further determine aneurysm instability that otherwise cannot be characterized by conventional imaging techniques. The current manuscript reviews conventional imaging techniques and their value and limitations in cerebral aneurysm characterization, and evaluates the applications, value and limitations of advanced aneurysm imaging and post-processing techniques including intracranial vessel wall MRA, 4D-flow, 4D-CTA, and computational fluid dynamic simulations.

What the Canadian public (mis)understands about eyes and eye care

CLINICAL RELEVANCE

Inadequate public knowledge about eyes and eye care poses avoidable risks to vision-related quality of life.

BACKGROUND

This study of eye care knowledge among Canadians extends earlier findings from focus groups.

METHODS

Perceptions about eyes and eye care were sought using a 21-item online survey and snowball sampling. Inclusion criteria were living in Canada and being at least 18-years old; eye care professionals and staff were excluded. Response frequencies were converted to percentages, with eye condition items analysed according to 'expected' or 'unexpected' eye impacts. Proportions selecting these impacts or 'unsure' were determined.

RESULTS

There were 424 respondents: 83.0% aged 20-65 years and 69.6% female. Mismatches existed between perceived recommendations and behaviours for booking eye exams: within two years (86.7% vs. 68.4%) and symptom-driven (3.3% vs. 13.0%). First eye exams after age one year were deemed appropriate by 43.6%. Few respondents associated glaucoma with no symptoms (6.0%) or amblyopia with blurred vision (13.5%). A notable proportion incorrectly related tunnel vision with age-related macular degeneration (AMD, 36.8%) and cataract (21.9%). Identifying all 'expected' responses was unlikely for glaucoma (1.9%), amblyopia (6.7%), and cataract (12.0%). Most respondents identified no 'expected' effects for glaucoma (63.8%) and AMD (46.2%) and some 'expected' effects for cataract (59.5%) and amblyopia (72.6%). Selecting 'unsure' was 9-10 times more common among respondents choosing no 'expected' impacts than those choosing some. Awareness of thyroid-associated eye disease was lowest (32.4%) of seven conditions. Respondents were most likely to consult optometrists for routine eye exams, eye disease, diabetes eye checks and blurred vision but family physicians for red eyes and sore eyes. Respondents typically paid for their eye exams and eyewear but wanted government to pay.

CONCLUSION

Vision-threatening knowledge gaps and misinformation about eyes and eye care among Canadian respondents highlight the need for accessible, targeted public education.

Handmade models for aneurysm surgery: A useful tool for training

Background

Aneurysm surgery is considered difficult by young and trainee neurosurgeons. This is due to difficulty in understanding orientation of aneurysm complex (proximal and distal vessels, aneurysm neck, and fundus) in relation to the surrounding structures (skull, brain, vessels, and nerves) after head is rotated, extended, and fixed on the head frame. Virtual three-dimensional (3D) imaging studies and 3D-printed models help young neurosurgeons but are not accessible to most of the centers due to need for resources (human and equipment). Authors used handmade 3D models of aneurysm complex to train young neurosurgeons before and during surgery to make them understand steps to treat it.

Methods

RadiAnt DICOM viewer software (2022.1.1, 64-bit, Medixant, Poznan, Poland) was used for acquiring 3D Volume Rendering Technique images to make aneurysm models preoperatively. Twisted 20 Gauze galvanized iron wires were used for making proximal and distal branches and Epoxy Putty (M-seal, Pidilite ^® industries, Mumbai, India) was used to make smooth surfaces of the vessels, aneurysm necks, and fundi. Models were used in operating room (OR) before and during surgery to help surgeons and trainees get oriented to the aneurysm complexes.

Results

Handmade models, oriented as per patients' head position, were useful to make surgeons and trainees to understand projection of various components of the aneurysm complex in relation to adjacent structures, especially skull base, during both preoperative planning and in OR even before completion of the dissection.

Conclusion

Handmade models of aneurysms are inexpensive tool and can help trainee neurosurgeons to plan and execute surgical management of aneurysms.

Follow-Up by Transcranial Doppler After Rupture of a Giant Intracranial Aneurysm

Giant intracranial aneurysms (GIA) are rare and manifest primarily through subarachnoid hemorrhage (SAH), cerebral ischemia, or progressive symptoms of mass effect. Transcranial Doppler (TCD) can be used to monitor cerebral vasospasm after treatment of intracranial aneurysm allowing the adjustment of therapeutics and avoiding complications. The authors present a clinical case of a patient with a ruptured intracranial giant aneurysm in which TCD was essential to monitor vasospasm and intracranial hypertension (IH). A 53-year-old male was admitted due to a sudden headache and impaired consciousness, left hemiparesis, and dysarthria. Cerebral CT scan and CT angiography at admission showed a giant aneurysm of the right middle cerebral artery (MCA) with extensive and diffuse intraventricular SAH of Fisher grade IV and Hunt and Hess grade 4. Clipping, placement of an intracranial pressure sensor, and external ventricular drain (EVD) were performed on the same day, with difficulty in preserving the M2 branch and complicated by postoperative extensive right MCA ischemia. On day three of hospitalization, TCD revealed an increased pulsatility index (>1.5) with clinical deterioration leading to re-intervention for a decompressive craniectomy. On day six, a TCD follow-up was performed to monitor blood flow complications, and particularly vasospasm, showing a severe increase in middle blood flow velocity (MBFV) in the right MCA of 205 cm/s and Lindegaard Index > 6. Daily surveillance by TCD was maintained to guide clinical management since the attempt to withdraw the EVD led to clinical deterioration with subsequent worsening of vasospasm. Improvement occurred after surgery as ventriculoperitoneal shunt insertion was performed. TCD had a major role in the clinical orientation of SAH as well as in intracranial pressure management and was decisive to establish long-term treatment.

Experimental Induction of Intracranial Aneurysms in Rats: A New Model Utilizing a Genetic Modification within the EDNRA Gene

The rupture of an intracranial aneurysm (IA) leads to life-threatening subarachnoid hemorrhage. Aside from well-established risk factors, recently published genome-wide association studies of IA revealed the strong association of a common variant near the endothelin receptor type A (EDNRA) gene with IA risk. However, the role of EDNRA in the pathogenesis of IA remains unclear. The aim of this study was to investigate the influence of a genetic modification within the EDNRA gene on IA pathogenesis in a novel in vivo model. Adult wild-type Sprague–Dawley rats (WT rats) and genetically modified rats (EDNRA rats) were used for the induction of IA using arterial hypertension (HT). Animals were stratified into four groups: WT rats without (WT_CTL) and with induction of HT (WT + HT), as well as EDNRA rats without (EDNRA_CTL) and with induction of HT (EDNRA + HT). Blood pressure (BP) was observed for 12 weeks. After the observation period, cerebral arteries were analyzed for morphological (i.e., aneurysmal) changes as well as histological and functional changes by immunofluorescence and functional investigation. In the groups of rats with induction of HT, BP was higher in EDNRA + HT compared with that in WT + HT. No IAs were observed in WT_CTL and EDNRA_CTL but were found in WT + HT and EDNRA + HT. There was no histological difference in the immunofluorescence of EDNRA between all groups. Contractility and potency of endothelin-1 differed between the groups in functional investigation. In summary, we created a new model that is suitable for further studies for better understanding of the role of EDNRA in IA pathogenesis.

Management of multiple and unruptured cerebral aneurysms

The incidence of multiple aneurysms was 10.7–34% of CA. Multiple associated factors were found; hypertension was the most significant one and others like advancing age and female sex were also documented. The estimated prevalence of UA is 5–10%. They include those aneurysms that did not rupture and discovered incidentally and those presented with symptoms rather than SAH, e.g., cranial nerve palsy or mass effect. Unruptured intracranial aneurysms are diagnosed with higher frequency nowadays as a result of imaging techniques improvement. The reported annual rate of rupture of UA is approximately 0.7–1%. The natural history of unruptured cerebral aneurysms cannot be extrapolated from the evaluation of individuals with ruptured aneurysms. Multiple cerebral aneurysms pose an even greater risk than a single aneurysm; the risk of rebleeding from the original aneurysm is larger and occurs sooner. The natural course of the disease has led to a consensus that all multiple unruptured aneurysms should be treated when technically viable. However, the prophylactic treatment of multiple unruptured is still controversial. Weighing the risk of intervention to the risk of observation is a mandatory pathway. Factors like age of patients, size and location of the aneurysms influence the decision-making and the type of therapy to be elected.

Vascular headache an traumatic brain injury

In a medical emergency, the most urgent patients at significant risk of death are those witha cerebrovascular accident and those with traumatic brain injury. Many are admitted withdiminished conscience status (coma) and focal neurological deficits. In the evaluation ofthese patients, neuroimaging is indispensable in order to identify the type of lesion andthe location of the brain where it is located.In the case of stroke, we can subdivide it into hemorrhagic and ischemic. Among hemorrhagic hemorrhages, we can mention (1) spontaneous intracerebral hematomasand (2) hemorrhages due to rupture of an intracranial aneurysm, with subarachnoidhemorrhage leading.Patients with head trauma are critical; even those who arrive at the hospital alert andoriented can decrease their level of consciousness in a few hours due to an intracranialhematoma, edema, or cerebral contusion.Thus, the availability of performing neuroimaging evaluations, using computed tomography and magnetic resonance imaging, or even digital angiography, is vital for continuoussupervision of this type of patient. The exams often require repetition several times due tothe rate of evolution of vascular lesions and after head trauma.A warning sign in these types of patients is headache. In the intracranial aneurysmal rupture, we classically have the thunderclap headache, an explosive, sudden pain mentionedas the worst pain the individual has suffered in his or her life. The pericranium and someintracranial structures are sensitive to nociceptive stimuli, such as the dura mater, largearteries, and venous sinuses. The brain is relatively insensitive to painful stimuli.This narrative review aims to inform the importance of neuroimaging assessment of patients with stroke and traumatic brain injury in an emergency department. In conclusion,a neuroimaging evaluation is paramount in addition to a neurological and physicalexamination of the critically ill patient with cerebrovascular disease or who has suffereda traumatic brain injury

Effects of different stent wire mesh densities on hemodynamics in aneurysms of different sizes

Background

Intracranial stents are used to treat aneurysms by diverting the blood flow from entering into the aneurysmal dome. Although delayed rupture is rare, clinical outcomes are extremely poor in such cases. Hemodynamics after stent deployment may be related to delayed rupture and a better understanding of the basic characteristics of pressure changes resulting from stent deployment is needed; therefore, this study investigated the relationships between hemodynamics in aneurysms of different sizes treated using stents of different wire mesh densities.

Methods

Using computational fluid dynamics analysis, parameters related to velocity, volume flow rate, pressure, and residual volume inside the aneurysm were evaluated in digital models of 5 basic aneurysms of differing sizes (Small, Medium, Medium-Large, Large, and Giant) and using 6 different types of stent (varying number of wires, stent pitch and wire mesh density) for each aneurysm.

Results

Regardless of the aneurysm size, the velocity inside the aneurysm and the volume flow rate into the aneurysm were observed to continuously decrease up to 89.2% and 78.1%, respectively, with increasing stent mesh density. In terms of pressure, for giant aneurysms, the pressure on the aneurysmal surface elevated to 10.3%, then decreased to 5.1% with increasing stent mesh density. However, in smaller aneurysms, this pressure continuously decreased with increasing stent mesh density. The flow-diverting effect of the stents was limited when a stent with low mesh density (under 20%) was used with a giant aneurysm.

Conclusions

The present results indicate that the selection of appropriate stents according to aneurysm size may contribute to reduced risks of hemodynamic alternations related to stent deployment, which could reduce the incidence of delayed rupture.

Comparison of the Jcerity Endoscoper Airway with the LMA supreme for airway management in patients undergoing cerebral aneurysm embolization: a randomized controlled non-inferiority trial

BACKGROUND

Jcerity Endoscoper Airway is a new back-open endoscopic laryngeal mask airway device with a unique design. Our study sought to compare the implantation, ventilation quality and complications of JEA (Jcerity Endoscoper airway) versus LMA (Laryngeal Mask Airway) Supreme in the procedure of cerebral aneurysm embolization.

METHODS

In this prospective, randomised clinical trial, 182 adult patients with American Society of Anesthesiologists class Ι-II scheduled for interventional embolization of cerebral aneurysms were randomly allocated into the Jcerity Endoscoper airway group and the LMA Supreme group. We compared success rate of LMA implantation, ventilation quality, airway sealing pressure, peak airway pressure, degree of blood staining, postoperative oral hemorrhage, sore throat and other complications between the groups.

RESULTS

There were no significant differences between the groups in terms of one-time success rate of LMA implantation, ventilation quality, airway sealing pressure or airway peak pressure. However, LMA Supreme group showed a higher degree of blood staining than the JEA group when the laryngeal mask airway was removed (P = 0.04), and there were also more oral hemorrhages and pharyngeal pain than JEA group (P = 0.03, P = 0.02). No differences were observed between groups in terms of other airway complications related to the LMA.

CONCLUSIONS

The JEA could not only achieve comparable one-time success rate of implantation and quality of ventilation as the LMA Supreme, but also have lower blood staining degree of mask and less sore throat in patients undergoing perioperative anticoagulation for cerebral aneurysm interventional embolization.

TRIAL REGISTRATION

Chinese Clinical Trial Registry, ChiCTR2100044133 ; Registered 11/03/2021. Statement: This study adheres to CONSORT guidelines.

Optimizing Small, Low-Risk, Unruptured Intracranial Aneurysm Treatment Using Game Theory

The incidental diagnosis of unruptured intracranial aneurysms has been increasing in the past several decades. A significant proportion represent small, low-risk, unruptured intracranial aneurysms for which there is equipoise on whether to offer treatment or conservative management. Given this uncertainty, patients may not always be comfortable with their physicians' recommendations. Herein, we use game theory to study the interactions between physicians and patients to determine how conflict and cooperation affect the management of small, low-risk, unruptured intracranial aneurysms. We constructed a game theory model of the interaction between physicians and patients with respect to decision-making for a small, low-risk, unruptured intracranial aneurysm in an asymptomatic patient when there is perceived equipoise between whether to treat or manage conservatively. Assuming that both the physician and patient are rational and eliciting individual patient preferences is not practical, the physician should play the game based on an ex ante probability of meeting a patient with a certain type of preference. This recommendation means that the expectations of the physician regarding the patient's preferences should guide the decision to offer treatment or conservative management as a first option for a small, asymptomatic, low-risk, unruptured intracranial aneurysm for which there is clinical equipoise.

Epidemiological Characteristics and Surgical Outcomes of Unruptured Intracranial Aneurysms: A Real-world Study

BACKGROUND: This study was aimed at epidemiological analysis of unruptured intracranial aneurysms (IAs) regarding their location, size, multiplicity, type of intervention provided, and associated complications in the Kazakhstani population. METHODS: We performed a retrospective analysis of a cohort of 400 patients diagnosed with IA admitted to the Central Clinical Hospital of Almaty, Republic of Kazakhstan, a referral hospital for the treatment of cerebrovascular disease. Patients admitted between January 1, 2019 and December 31, 2019 with radiologically confirmed diagnosis of unruptured IA were included in the study. RESULTS: Overall, there were 400 patients with a 2.8 female/male ratio. The bulk of aneurisms – 96.0% – were of size <25 mm in diameter and single. Median age of patients was 55 years and the youngest patient was 22-years-old, while the oldest patient aged 83 years. The left internal carotid artery (ICA) was the most common site if IA localization followed by the right ICA. The left and right middle cerebral arteries were the second most common localization sites. More than a half of patients presented with aneurysm-related complications before the intervention, of which subarachnoid hemorrhage was the most common type. Embolization with or without stenting was performed in more than 50% of patients and 96.5% of all surgeries were not associated with complications. CONCLUSION: There is a need for careful consideration of clinical characteristics and surgical outcomes of patients with unruptured IA in a real-world practice as these data are needed for the development of management strategies.

Biophysical targeting of high-risk cerebral aneurysms

Localized delivery of diagnostic/therapeutic agents to cerebral aneurysms, lesions in brain arteries, may offer a new treatment paradigm. Since aneurysm rupture leading to subarachnoid hemorrhage is a devastating medical emergency with high mortality, the ability to noninvasively diagnose high-risk aneurysms is of paramount importance. Moreover, treatment of unruptured aneurysms with invasive surgery or minimally invasive neurointerventional surgery poses relatively high risk and there is presently no medical treatment of aneurysms. Here, leveraging the endogenous biophysical properties of brain aneurysms, we develop particulate carriers designed to localize in aneurysm low-shear flows as well as to adhere to a diseased vessel wall, a known characteristic of high-risk aneurysms. We first show, in an in vitro model, flow guided targeting to aneurysms using micron-sized (2 μm) particles, that exhibited enhanced targeting (>7 folds) to the aneurysm cavity while smaller nanoparticles (200 nm) showed no preferable accumulation. We then functionalize the microparticles with glycoprotein VI (GPVI), the main platelet receptor for collagen under low-medium shear, and study their targeting in an in vitro reconstructed patient-specific aneurysm that contained a disrupted endothelium at the cavity. Results in this model showed that GPVI microparticles localize at the injured aneurysm an order of magnitude (>9 folds) more than control particles. Finally, effective targeting to aneurysm sites was also demonstrated in an in vivo rabbit aneurysm model with a disrupted endothelium. Altogether, the presented biophysical strategy for targeted delivery may offer new treatment opportunities for cerebral aneurysms.