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Intracranial aneurysm is a cerebrovascular disease associated with a high rupture risk, often resulting in death or severe disability. Recent advances in AI enable the prediction of intracranial aneurysm initiation, progression, and rupture through medical image analysis. Despite growing research interest, there is a shortage of publicly available datasets for training and validating AI models. This paper presents a comprehensive dataset comprising high-resolution CTA images of 99 patients with 105 MCA aneurysms and 44 normal healthy controls, along with their respective clinical data and 3D models of aneurysms and the parent arteries derived from the CTA images. Furthermore, recognizing the significance of blood hemodynamics on aneurysm development, this dataset also included the morphological and hemodynamic parameters obtained by computational fluid dynamics (CFD) for each patient and healthy control, which can be utilized by researchers without prior CFD experience. This dataset will facilitate hypothesis-driven or data-driven research on intracranial aneurysms, and has the potential to deepen our understanding of this disease., Competing Interests: Competing interests The authors declare no competing interests., (© 2024. The Author(s).)

Currently, the growing interest in radiomics within the clinical practice has prompted some researchers to differentiate the rupture status of intracranial aneurysm (IA) by developing radiomics-based machine learning models. However, systematic evidence supporting its performance remains scarce. The purpose of this meta-analysis and systematic review is to assess the diagnostic performance of radiomics-based machine learning for the early detection of IA rupture and to offer evidence-based recommendations for the application of radiomics in this area. PubMed, Cochrane, Embase, and Web of Science databases were searched systematically up to March 2, 2024. The Radiomics Quality Score (RQS) was employed to assess the risk of bias in all included primary studies. We separately discussed the diagnostic or predictive performance of machine learning for IA rupture status based on task type (diagnosis or prediction).  We finally included 15 original studies covering 9,111 IA cases. In the validation cohort, radiomics demonstrated a sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio, as well as SROC curve of 0.84 (95% CI: 0.76-0.90), 0.82 (95% CI: 0.77-0.86), 4.7 (95% CI: 3.7-5.8), 0.19 (95% CI: 0.13-0.29), and 24 (95% CI: 15-40), respectively, for the diagnostic task of aneurysm rupture status. Only 2 studies (3 models) addressed predictive tasks, with sensitivity and specificity ranging from 0.77 to 0.89 and from 0.69 to 0.87, respectively. Radiomics-based machine learning exhibits promising accuracy for early identification of IA rupture status, whereas evidence for its predictive capability is limited. Further research is needed to validate predictive models and provide insights for developing specialized strategies to prevent aneurysm rupture., Competing Interests: Declarations Ethics approval and consent to participate Not applicable. Consent for publication Not applicable. Competing interests The authors declare no competing interests., (© 2024. The Author(s).)

Background and Purpose: Prediction of aneurysm instability is crucial to guide treatment decisions and to select appropriate patients with unruptured intracranial aneurysms (IAs) for preventive treatment. High-resolution 4D MR flow imaging and 3D quantification of aneurysm morphology could offer insights and new imaging markers for aneurysm instability. In this cross-sectional study, we aim to identify 4D MR flow imaging markers for aneurysm instability by relating hemodynamics in the aneurysm sac to 3D morphologic proxy parameters for aneurysm instability., Materials and Methods: In 35 patients with 37 unruptured IAs, a 3T MRA and a 7T 4D MRI flow scan were performed. Five hemodynamic parameters-peak-systolic wall shear stress (WSS MAX ) and time-averaged wall shear stress (WSS MEAN ), oscillatory shear index (OSI), mean velocity, and velocity pulsatility index-were correlated to 6 3D morphology proxy parameters of aneurysm instability-major axis length, volume, surface area (all 3 size parameters), flatness, shape index, and curvedness-by Pearson correlation with 95% CI. Scatterplots of hemodynamic parameters that correlated with IA size (major axis length) were created., Results: WSS MAX and WSS MEAN correlated negatively with all 3 size parameters (strongest for WSS MEAN with volume ( r = -0.70, 95% CI -0.83 to -0.49) and OSI positively (strongest with major axis length [ r = 0.87, 95% CI 0.76-0.93]). WSS MAX and WSS MEAN correlated positively with shape index ( r = 0.61, 95% CI 0.36-0.78 and r = 0.49, 95% CI 0.20-0.70, respectively) and OSI negatively ( r = -0.82, 95% CI -0.9 to -0.68). WSS MEAN and mean velocity correlated negatively with flatness ( r = -0.35, 95% CI -0.61 to -0.029 and r = -0.33, 95% CI -0.59 to 0.007, respectively) and OSI positively ( r = 0.54, 95% CI 0.26-0.74). Velocity pulsatility index did not show any statistically relevant correlation., Conclusions: Out of the 5 included hemodynamic parameters, WSS MAX , WSS MEAN , and OSI showed the strongest correlation with morphologic 3D proxy parameters of aneurysm instability. Future studies should assess these promising new imaging marker parameters for predicting aneurysm instability in longitudinal cohorts of patients with IA., (© 2024 by American Journal of Neuroradiology.)

Background: Flow diversion has revolutionized the management of wide-necked intracranial aneurysms (IAs). We aimed to assess the effectiveness and safety of the new generation 64-wire Surpass Evolve for the treatment of unruptured small/medium-sized IAs., Methods and Results: This is a subanalysis from the SEASE (Safety and Effectiveness Assessment of the Surpass Evolve) registry, an observational cohort study including 15 academic institutions in North America and Europe between July 2020 and October 2022. Patients with wide-necked saccular IAs, measuring <12 mm along the internal carotid artery and vertebrobasilar system, and treated with the Surpass Evolve were included. Primary effectiveness was complete occlusion (Raymond-Roy class 1) at follow-up (core laboratory adjudicated), and primary safety was major stroke (ischemic/hemorrhagic) in the territory supplied by the target artery or death. A total of 129 cases with 135 IAs were included (median age 59 years, 85.3% women). Median maximum IAs size and neck size were 5.1 and 3.9 mm, respectively. Most IAs were in the internal carotid artery C6 (65.9%, 89/135) and C7 (14.1%, 19/135) segments. At a median follow-up time of 10.2 months (interquartile range, 6.4-12.8), complete occlusion was 77.1% (101/131), ≥50% in-stent stenosis was 8.8% (11/125), and retreatment was 0.8% (1/125). Major stroke and mortality were reported in 2 (1.6%) patients and 1 (0.8%) patient, respectively. Size was the only factor associated with higher odds of incomplete occlusion (adjusted odds ratio, 1.2 [95% CI, 1.02-1.5]; P =0.03)., Conclusions: Patients with small/medium-sized IAs can be effectively treated using the Surpass Evolve, a new generation, 64-wire, cobalt-chromium flow diverter.

Introduction: Stent-assisted coil embolisation (SACE) for the treatment of unruptured cerebral aneurysms has been increasingly used. Long-term advantages of antiplatelet therapy (APT) post-SACE treatment are still not well understood. We investigated the long-term effects of APT on clinical prognosis after SACE., Patients and Methods: We conducted a retrospective study using nationwide health insurance claims data from South Korea, including patients with cerebral aneurysm treated with SACE from January 2009 to December 2020. The study outcomes consisted of the occurrence of cerebral infarction and major haemorrhage. To evaluate the impact of APT, we employed a multivariable time-dependent Cox proportional hazards regression model for each of the three distinct periods: 1-12 months, 12-24 months and >24 months after SACE., Results: This study included 17 692 unruptured cerebral aneurysm patients treated with SACE. During the mean follow-up of 4.2 years, there were 379 (2.1%) patients with cerebral infarction and 190 (1.1%) patients with major haemorrhage. The percentage of patients receiving APT was 79.5% at 1 year, which gradually decreased to 58.3% at 2 years after SACE. APT was beneficial in preventing cerebral infarction within 12 months after SACE (adjusted HR (aHR) 0.56; 95% CI, 0.35 to 0.89; p=0.014). After 12 months, this association was not evident. APT increased the risk of haemorrhage after 24 months (aHR 1.76; 95% CI 1.11 to 2.87; p=0.016)., Discussion and Conclusion: Our findings suggest that in patients with unruptured cerebral aneurysm treated with SACE, the reasonable duration of APT for preventing cerebral infarction might be 1 year after SACE., Competing Interests: Competing interests: MB received research grants from Daewoong Pharmaceuticals. JY received research grants from Chong Kun Dang Pharmaceuticals. JK received research grants from Chong Kun Dang and Myung In Pharmaceuticals. The authors declare no potential conflicts of interest., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: High-flow bypasses with parent vessel occlusion are required for complex aneurysms originating from the ICA or MCA. Traditional graft options are the saphenous vein however, it has a higher rate of thrombus formation than an arterial graft. The radial artery is commonly used, however, tapers in its distal course and is contraindicated in some patients while the lateral circumflex femoral artery is an excellent graft vessel and easy to harvest., Method: We present our technique and experience harvesting the lateral circumflex femoral artery as an alternative graft vessel for high-flow bypasses., Conclusion: The lateral circumflex femoral artery is easy to harvest and is a reliable graft vessel for high-flow bypasses for complex aneurysms., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

Intracranial arterial aneurysms in children are rare. They differ from adult aneurysms in their etiology, natural history, and management approach. Unruptured asymptomatic aneurysms in children can often be observed for growth over time. Endovascular treatment has become the primary interventional modality in children with intracranial aneurysms. The authors discuss the management approach to pediatric intracranial aneurysms., (Crown Copyright © 2024. Published by Elsevier Inc. All rights reserved.)

Objective: Outpouchings, particularly those originating from the posterior communicating artery off the internal carotid artery (Pcom-Ops), are often unable to be categorized definitively as aneurysms or infundibula resulting in frequent clinical imaging and follow-up. We aimed to investigate potential correlations between growth and rupture rates and easily definable imaging characteristics in Pcom-Ops., Methods: We analyzed CT and MR imaging of Pcom-Ops identified in a case series of patients seen between 2007 and 2022. For each outpouching, the length of the base, hypotenuse, and round defect, defined as the deviation from triangular shape, were calculated. These measurements were used to estimate the conical volume and eccentricity of the Pcom-Op., Results: 179 Pcom-Ops were identified from 152 patients who were followed for an average of for 3.2 ± 3.2 years. Bilateral Pcom-Ops were present in 17.8 % patients and 7.2 % had an underlying connective tissue disease. Only one Pcom-Op in a patient with polycystic kidney disease subsequently became a clear aneurysm after 6.3 years. The average approximated volume and round defect at presentation were 2.3 ± 2.2 mm 3 and 0.29 ± 0.16 mm, respectively. Volume and round defect changed minimally over time followed. Outlier analysis of round defect, determined by Z-score more than 3 standard deviations above the mean, was not associated with evolution into clear aneurysms., Conclusion: Pcom-Ops rarely enlarge or rupture. Pcom-Op eccentricity does not predict high risk Pcom-Ops. Thus Pcom-Ops in general may not require close follow-up over time. However, Pcom-Ops in patients with connective tissue diseases should be monitored more closely., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: Despite advances in neurosurgical techniques and technology, the management of ruptured giant fusiform MCA aneurysms remains challenging. In the literature, microsurgical intervention is the most commonly described approach. However, recent advancements in endovascular techniques have expanded therapeutic options and as a result there is no consensus on the optimal management of these aneurysms., Methods: A literature search was performed through the PubMed, Google Scholar, and Embase databases, for surgical and endovascular management of ruptured giant fusiform MCA aneurysms. Inclusion criteria included: fusiform morphology, hemorrhage, major diameter greater than 2.5 cm and located along the MCA., Results: Literature review yielded 21 studies published from 1981 to 2023 and a total of 32 patients ages 33.40 ± 18.28. The male to female ratio was 1.9:1. The average Hunt and Hess score upon presentation in the total population was 2.78 ± 1.48, and the average pre-operative mRS of the total population was 2.75 ± 1.83. The average major diameter was 3.80 ± 1.85 cm. Average follow-up was 8.9 ± 9.74 months. There was no statistical difference in age (p = 0.5609), pre-operative mRS (p = 0.2355), Hunt and Hess scale (p = 0.183), aneurysm major diameter (p = 0.594) or follow-up (0.8922) between the two modalities. There was no significant difference in clinical outcome between microsurgical and endovascular intervention, nor was there a significant difference when stratified according to sex, major diameter, or location along the MCA. Two case examples are presented after management with cerebral revascularization., Conclusion: Our analysis underscores the absence of statistical differences in clinical outcomes between microsurgical and endovascular strategies for ruptured giant fusiform MCA aneurysms, which highlights the need for complex surgical revascularization as represented on the illustrative cases where no endovascular option was available., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)

Objective: This study evaluates the effectiveness of multimodal image fusion (MIF) using silent and time-of-flight (TOF) magnetic resonance angiography (MRA) and computed tomography (CT) for preoperative planning in patients with intracranial aneurysms who have contraindications to contrast media., Materials and Methods: A retrospective study included 40 patients with intracranial aneurysms, diagnosed using three-dimensional computed tomography angiography (CTA). These patients underwent both Silent and TOF MRA scans, followed by a CTA scan. The multi-image fusion (MIF) technique, applied using 3DSlicer software, integrated the silent/TOF-MRA with CT images for preoperative assessment. This study compared the image quality, aneurysm detection sensitivity, and anatomic accuracy of the MIF images with those of three-dimensional CTA., Results: Silent-MRA-CT fusion images demonstrated higher sensitivity (95.5%) and lower false negative rates (4.5%) compared with TOF-MRA-CT. Furthermore, silent-MRA-CT fusion images outperformed TOF-MRA-CT in terms of signal homogeneity, venous signal interference suppression, and aneurysm visibility (all P < 0.05). The interclass correlation coefficient and kappa values for aneurysm morphology and shape indicated superior measurement consistency and shape concordance of silent-MRA-CT with CTA compared with TOF-MRA-CT (all P < 0.01)., Conclusion: This study supports the use of silent/TOF-MRA-CT fusion imaging as a reliable alternative to CTA, noting that silent-MRA-CT closely mirrors CTA. Contrast-free MRA-CT fusion images have the potential to be used for preoperative planning in patients with intracranial aneurysms who have contraindications to contrast., Competing Interests: The authors declare no conflict of interest., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Although arterial stiffness is known as a biomarker for cardiovascular events and stroke, there is limited information in the literature regarding the stiffness of intracranial aneurysms. In this study, we aim to assess the stiffness of intracranial aneurysms using 4D Flow MRI., Methods: A total of 27 aneurysms in 25 patients with internal carotid artery aneurysms were included in this study. Using 4D Flow MRI, we measured the arterial pulse wave form during a cardiac cycle at planes proximal and distal to the target aneurysm. The damping of these waveforms through the aneurysm was defined as the aneurysm damping index (ADI) and compared to the contralateral side. We also investigated the clinical factors related to the ADI., Results: ADI assessment was successful in all cases. The average ADI was 1.18±0.28, which was significantly larger than 1.0 (P = 0.0027 [t-test]). The ADI on the aneurysm side was larger than on the contralateral side (1.19±0.30 vs 1.05±0.17, P = 0.029 [t-test]). On multivariate analysis, the use of beta-blockers (β=0.46, P = 0.015) and smoking history (β=-0.22, P = 0.024) showed a significant correlation with ADI., Conclusion: We have proposed a novel method to observe arterial pulse wave dumping through intracranial aneurysm using 4D Flow MRI. The damping can be quantitatively observed, and the ADI has correlations with clinical factors such as antihypertensive drugs and smoking. Further studies should focus more on evaluating aneurysm stiffness and its clinical applications., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial or personal relationships that could be viewed as influencing the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Masson SAS.. All rights reserved.)

Background: Hemodynamic factors play an important role in the formation and rupture of intracranial aneurysms. Blood viscosity has been recognized as a potential factor influencing the hemodynamics of aneurysms. Computational fluid dynamics (CFD) is one of the main methods to study aneurysm hemodynamics. However, current CFD studies often set the viscosity to a standard value, neglecting the effect of individualized viscosity on hemodynamics. We investigate the impact of blood viscosity on hemodynamics in large intracranial aneurysm (IA) and assess the potential implications for aneurysm growth and rupture risk., Methods: CFD simulations of 8 unruptured large internal carotid artery aneurysms were conducted using pulsatile inlet conditions. For each aneurysm, CFD simulations were performed at 5 different viscosity levels (0.004, 0.006, 0.008, 0.010, and 0.012 Pa·s). Differences in hemodynamic parameters across viscosity levels were compared using paired t-tests, and the correlation between viscosity and hemodynamic parameters was analyzed., Results: Increasing blood viscosity leads to significant decrease in blood flow velocity within aneurysms. Time-averaged wall shear stress (WSS) showed significant positive correlation with viscosity, particularly at the aneurysm neck. Oscillatory shear index (OSI) showed general decreasing trend with increased viscosity, while it displayed an irregular pattern in a few cases., Conclusions: Variations in viscosity markedly influence velocity, WSS, and OSI in aneurysms, suggesting a role in modulating aneurysm growth and rupture risk. Incorporating patient-specific viscosity values in CFD simulations is vital for accurate and reliable outcomes., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Introduction: During infancy, infectious aneurysms are uncommon and potentially fatal lesions with an imminent risk of intracranial hemorrhage development., Case Presentation: A 1-month-old infant presented with loss of consciousness and clonic movements of the right superior limb after a work-up for Hirschsprung's disease. His physical exam revealed stupor, miosis, anterior fontanelle swelling, and hyperreflexia of the right superior limb. Blood cultures were positive for Candida albicans. In addition, brain imaging revealed an intraparenchymal hematoma in the left temporal lobe and a saccular aneurysm at the M3 segment of the left middle cerebral artery. Upon careful discussion with the patient's family, he underwent evacuation of the hematoma and aneurysm repair. His postoperative clinical course was uneventful. At the 5-month follow-up, a brain MRI showed encephalomalacia in the area of prior hemorrhage. Furthermore, he had preserved motor function and adequate psychomotor development on subsequent pediatric evaluations., Conclusion: Microsurgical management of ruptured mycotic aneurysms demands a systematic work-up and nuanced appraisal of clinical and aneurysmal factors. Operating in a confined space and considering the fragile nature of aneurysms are of utmost relevance for effectively treating these lesions., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: Intraoperative 2D quantitative angiography (QA) for intracranial aneurysms (IAs) has accuracy challenges due to the variability of hand injections. Despite the success of singular value decomposition (SVD) algorithms in reducing biases in computed tomography perfusion (CTP), their application in 2D QA has not been extensively explored. This study seeks to bridge this gap by investigating the potential of SVD-based deconvolution methods in 2D QA, particularly in addressing the variability of injection durations., Purpose: Building on the identified limitations in QA, the study aims to adapt SVD-based deconvolution techniques from CTP to QA for IAs. This adaptation seeks to capitalize on the high temporal resolution of QA, despite its two-dimensional nature, to enhance the consistency and accuracy of hemodynamic parameter assessment. The goal is to develop a method that can reliably assess hemodynamic conditions in IAs, independent of injection variables, for improved neurovascular diagnostics., Materials and Methods: The study included three internal carotid aneurysm (ICA) cases. Virtual angiograms were generated using computational fluid dynamics (CFD) for three physiologically relevant inlet velocities to simulate contrast media injection durations. Time-density curves (TDCs) were produced for both the inlet and aneurysm dome. Various SVD variants, including standard SVD (sSVD) with and without classical Tikhonov regularization, block-circulant SVD (bSVD), and oscillation index SVD (oSVD), were applied to virtual angiograms. The method was applied on virtual angiograms to recover the aneurysmal dome impulse response function (IRF) and extract flow related parameters such as Peak Height PH IRF , Area Under the Curve AUC IRF , and Mean transit time MTT. Next, correlations between QA parameters, injection duration, and inlet velocity were assessed for unconvolved and deconvolved data for all SVD methods. Additionally, we performed an in vitro study, to complement our in silico investigation. We generated a 2D DSA using a flow circuit design for a patient-specific internal carotid artery phantom. The DSA showcases factors like x-ray artifacts, noise, and patient motion. We evaluated QA parameters for the in vitro phantoms using different SVD variants and established correlations between QA parameters, injection duration, and velocity for unconvolved and deconvolved data., Results: The different SVD algorithm variants showed strong correlations between flow and deconvolution-adjusted QA parameters. Furthermore, we found that SVD can effectively reduce QA parameter variability across various injection durations, enhancing the potential of QA analysis parameters in neurovascular disease diagnosis and treatment., Conclusion: Implementing SVD-based deconvolution techniques in QA analysis can enhance the precision and reliability of neurovascular diagnostics by effectively reducing the impact of injection duration on hemodynamic parameters., (© 2024 American Association of Physicists in Medicine.)

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., (Copyright © 2024 Sociedad Española de Neurocirugía. Published by Elsevier España, S.L.U. All rights reserved.)

To investigate the clinical value of multi-slice spiral computed tomography (CT) angiography (MSCTA) combined with MRI in the diagnosis of cerebral aneurysm. A total of 90 patients with cerebral aneurysms diagnosed by DSA were selected as the subjects of this study. Another 30 patients with cerebral infarction were selected as negative controls (NC). Before diagnosis, all patients underwent comprehensive examination using MSCTA and MRI. The results of the comparison and the clinical data of all patients were retrospectively analyzed. MSCTA and MRI examinations can clearly show the specific location, shape, size and anatomical relationship with surrounding tissues of cerebral aneurysms. MSCTA diagnosed 82 patients and missed or misdiagnosed 8 patients in the 90 patients with cerebral aneurysm. The diagnostic sensitivity and accuracy of MSCTA were 91.1 (82/90) and 89.2 (107/120), respectively. MRI examination diagnosed 87 patients and missed or misdiagnosed 3 patients in the 90 patients with cerebral aneurysm. The diagnostic sensitivity and accuracy of MRI were 96.7 (87/90) and 96.7 (116/120), respectively. The sensitivity and accuracy of MSCTA combined with MRI were 100.0 (90/90) and 99.2 (119/120), respectively. MSCTA combined with MRI can not only display the whole picture of brain tissue, but also display the size, shape and relationship with the parent vessel of the aneurysm. The combination of MSCTA and MRI has high sensitivity and accuracy in diagnosing intracranial aneurysms, which provides a promising diagnostic protocol for patients with aneurysms.

Introduction: The Woven EndoBridge (WEB) device is emerging as a novel therapy for intracranial aneurysms, but its use for off-label indications requires further study. Using machine learning, we aimed to develop predictive models for complete occlusion after off-label WEB treatment and to identify factors associated with occlusion outcomes., Methods: This multicenter, retrospective study included 162 patients who underwent off-label WEB treatment for intracranial aneurysms. Baseline, morphological, and procedural variables were utilized to develop machine-learning models predicting complete occlusion. Model interpretation was performed to determine significant predictors. Ordinal regression was also performed with occlusion status as an ordinal outcome from better (Raymond Roy Occlusion Classification [RROC] grade 1) to worse (RROC grade 3) status. Odds ratios (OR) with 95 % confidence intervals (CI) were reported., Results: The best performing model achieved an AUROC of 0.8 for predicting complete occlusion. Larger neck diameter and daughter sac were significant independent predictors of incomplete occlusion. On multivariable ordinal regression, higher RROC grades (OR 1.86, 95 % CI 1.25-2.82), larger neck diameter (OR 1.69, 95 % CI 1.09-2.65), and presence of daughter sacs (OR 2.26, 95 % CI 0.99-5.15) were associated with worse aneurysm occlusion after WEB treatment, independent of other factors., Conclusion: This study found that larger neck diameter and daughter sacs were associated with worse occlusion after WEB therapy for aneurysms. The machine learning approach identified anatomical factors related to occlusion outcomes that may help guide patient selection and monitoring with this technology. Further validation is needed., Competing Interests: Declaration of competing interest None., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Cerebral aneurysms in children have a low incidence and accounts for less than 4% of all cerebral aneurysms. These aneurysms have been linked to various factors. Severe headache, seizures, and motor-sensory deficits are common presentations., Case Report: We describe the case of a 2-month-old male patient who presented with generalized tonic-clonic seizures for 4 days. At the hospital, he was stabilized with ventilatory support, sedation, and antiepileptic drugs. A NCCT (Head) showed intraparenchymal hemorrhage in the left fronto-parieto-temporal lobe and subarachnoid hemorrhage. Subsequently a CT angiogram revealed an aneurysm of the left M3 segment of MCA. Successfully, the patient underwent microsurgical clipping of aneurysm and evacuation of hematoma., Conclusions: Pediatric cerebral aneurysms differ from their adult counterparts, mainly in their etiology and evolution. As per literature, aneurysmal clipping and neurological endovascular therapy have shown similar results., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Object: Treatment of ruptured basilar artery trunk (BAT) aneurysms is challenging, and is associated with high complication and mortality rates. Herein, we analyzed the complications, long-term outcomes, and outcome predictors of endovascular treatment for ruptured BAT aneurysms., Methods: Between January 2011 and July 2023, 36 patients with 36 ruptured BAT aneurysms underwent endovascular treatment at our institution. The postprocedural complications and clinical and angiographic outcomes were subsequently reviewed, and the risk factors for postprocedural complications were evaluated., Results: All 36 aneurysms in 36 patients were treated successfully. The median clinical follow-up time was 47.0 (IQR: 10.5, 84.5) months. Overall, complications occurred in 10 (27.8%) patients, including 3 (8.3%) deaths. Ischemic events occurred in seven (19.4%) patients, while three (8.3%) patients had shunt-dependent hydrocephalus, of whom one (2.8%) patient had both shunt-dependent hydrocephalus and ischemic events. The cumulative survival rates at 3 and 5 years were 94.1% and 87.8%, respectively. The cumulative 3- and 5-year complication-free survival rates were 75.0% and 70.0%, respectively. Multivariate Cox regression analysis revealed that diabetes mellitus (HR:8.76, 95%CI:2.35-32.69, p=0.001), and Glasgow coma scale score ≤ 12 before the procedure (HR:5.04, 95%CI:1.40-18.12, p=0.013) were associated with overall postprocedural complications. The complete aneurysm occlusion rate was 61.5% at a median angiography follow-up time of 6.0 (IQR: 5.0, 6.0) months., Conclusions: Endovascular treatment is a safe and feasible option for treating ruptured BAT aneurysms. The rate of favorable outcomes at the final follow-up was satisfactory. However, postprocedural complications, particularly ischemic events, should be carefully considered., Competing Interests: Declaration of competing interest The authors declare that they have no conflict of interest., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background and Importance: Fusiform vertebrobasilar aneurysms carry significant morbidity. Endovascular strategies are preferred; however, unsafe or unfeasible access can call for innovative strategies., Clinical Presentation: An octogenarian patient with an enlarging fusiform proximal basilar artery aneurysm causing a sixth nerve palsy was found to have multiple anatomic features that precluded a transradial or transfemoral endovascular approach. She was thus treated with direct microsurgical access of the V3 segment of the vertebral artery for subsequent coil embolization and flow diversion., Conclusion: This case introduces a novel combined microsurgical and endovascular strategy for treating a complex partially thrombosed fusiform basilar artery aneurysm. This approach should be reserved only for patients where conventional endovascular access is dangerous or unfeasible., (Copyright © Congress of Neurological Surgeons 2024. All rights reserved.)

Objectives: Arterial calcification is thought to protect against rupture of intracranial aneurysms, but studies in a representative population of intracranial aneurysm patients have not yet been performed. The aim was to compare the prevalence of aneurysm wall calcification and intracranial carotid artery calcification (ICAC) between patients with an unruptured intracranial aneurysm (UIA) and a ruptured intracranial aneurysm (RIA)., Materials and Methods: We matched 150 consecutive UIA patients to 150 RIA patients on age and sex. Aneurysm wall calcification and ICAC were quantified on non-contrast enhanced computed tomography images with the modified Agatston score. We compared the prevalence of aneurysm wall calcification, ICAC, and severe ICAC (defined as a modified Agatston score in the fourth quartile) between UIA and RIA patients using univariate and multivariate conditional logistic regression models adjusted for aneurysm characteristics and cardiovascular risk factors., Results: Aneurysm wall calcification was more prevalent in UIA compared to RIA patients (OR 5.2, 95% CI: 2.0-13.8), which persisted after adjustment (OR 5.9, 95% CI: 1.7-20.2). ICAC prevalence did not differ between the two groups (crude OR 0.9, 95% CI: 0.5-1.8). Severe ICAC was more prevalent in UIA patients (OR 2.0, 95% CI: 1.1-3.6), but not after adjustment (OR 1.0, 95% CI: 0.5-2.3)., Conclusions: Aneurysm wall calcification but not ICAC was more prevalent in UIAs than in RIAs, which corresponds to the hypothesis that calcification may protect against aneurysmal rupture. Aneurysm wall calcification should be further assessed as a predictor of aneurysm stability in prospective cohort studies., Clinical Relevance Statement: Calcification of the intracranial aneurysm wall was more prevalent in unruptured than ruptured intracranial aneurysms after adjustment for cardiovascular risk factors. Calcification may therefore protect the aneurysm against rupture, and aneurysm wall calcification is a candidate predictor of aneurysm stability., Key Points: Aneurysm wall calcification was more prevalent in patients with unruptured than ruptured aneurysms, while internal carotid artery calcification was similar. Aneurysm wall calcification but not internal carotid artery calcification is a candidate predictor of aneurysm stability. Cohort studies are needed to assess the predictive value of aneurysm wall calcification for aneurysm stability., (© 2024. The Author(s).)

Background and Objectives: Distal basilar artery aneurysms (DBAs) are high-risk lesions for which endovascular treatment is preferred because of their deep location, yet indications for open clipping nonetheless remain. The subtemporal approach allows for early proximal control and direct visualization of critical posterior perforating arteries, especially for posterior-projecting aneurysms. Our objective was to describe our clinical experience with the subtemporal approach for clipping DBAs in the evolving endovascular era., Methods: This was a retrospective, single-institution case series of patients with DBAs treated with microsurgery over a 21-year period (2002-2023). Demographic, clinical, and surgical data were collected for analysis., Results: Twenty-seven patients underwent clipping of 11 ruptured and 16 unruptured DBAs with a subtemporal approach (24 female; mean age 53 years). Ten patients had expanded craniotomies for treatment of additional aneurysms. The aneurysm occlusion rate was 100%. Good neurological outcomes as defined by the modified Rankin Scale score ≤2 and Glasgow Outcome Scale score ≥4 were achieved in 21/27 patients (78%). Two patients died before hospital discharge, one from vasospasm-induced strokes and another from an intraoperative myocardial infarction., Conclusion: These results demonstrate that microsurgical clip ligation of DBAs using the subtemporal approach remains a viable option for complex lesions not amenable to endovascular management., (Copyright © Congress of Neurological Surgeons 2024. All rights reserved.)

Objectives: Distal anterior cerebral artery (DACA) aneurysms account for 1%-9% of all intracranial aneurysms. Microsurgical treatment is generally preferred for DACA aneurysms; however, it presents challenges owing to the anatomical complexities. Advances in neuro-interventional techniques have yielded promising results. This study aims to compare the clinical outcomes of DACA aneurysms treated with microsurgery and endovascular treatment (EVT) to elucidate the efficacy of EVT., Materials and Methods: A multicenter observational registry comprising 16 stroke centers was utilized for this study. Data was retrospectively and prospectively analyzed from 166 patients with DACA aneurysms in our database, which included 4,552 consecutive patients with ruptured or unruptured intracranial aneurysms who underwent microsurgical or endovascular treatment between January 2013 and December 2021., Results: Surgical clipping was performed in 115 patients, and 51 underwent coil embolization. The median follow-up duration was 15.3 months. No significant differences were observed in patient characteristics between the two treatment modalities. There were no differences in complication-related morbidity between the microsurgical treatment and EVT groups in either unruptured (10.5% vs. 9.1%, p=1.00) or ruptured aneurysms (5.2% vs. 6.9%, p=0.66). Coil embolization resulted in higher recurrence and retreatment rates than surgical clipping did, especially for ruptured aneurysms (2.6% vs. 27.6%, p<0.01)., Conclusions: Endovascular treatment is an alternative to microsurgery for DACA aneurysms especially in unruptured cases or the patients who have difficulty undergoing craniotomy due to their general condition, albeit with considerations for higher recurrence and retreatment rates, particularly in ruptured cases. Close follow-up is crucial for the effective management of these challenges. Further studies are needed to refine the treatment strategies for DACA aneurysms., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: The questions of whether the spatial resolution of navigated 3D-ultrasound (3D-US) power-Doppler angiography imaging rendered by existing 3D-US systems is sufficient for the intraoperative visualization of cerebral aneurysms, and in what percentage of cases, are largely unanswered. A study on this topic is lacking in the literature., Methods: From 2015 to 2022, we performed 86 surgeries on 83 aneurysm patients. Navigated 3D-US was used at the discretion of the operating neurosurgeons when available (i.e., not being used during parallel tumor surgeries). Twenty-five aneurysms (15 ruptured) were operated on using 3D-US; 22 aneurysms were located at the middle cerebral artery (MCA). Patient 3D-US power-Doppler angiography images and surgical reports were retrospectively reviewed to assess the intraoperative ultrasound visibility of aneurysms., Results: In 20 patients (80%) the aneurysms were successfully visualized. In five patients (20%), the aneurysms visualization was insufficient or absent. Nineteen of 22 aneurysms (86.4%) were visualized in the MCA aneurysm subgroup. We observed no association between aneurysm visibility and aneurysm size or the presence of subarachnoid hemorrhage. In the subgroup of MCA aneurysms, no association between aneurysm visibility and the presence of subarachnoid hemorrhage was found; a trend toward poor sonographic visibility of smaller aneurysms was observed (p = 0.09)., Conclusions: Our initial data show that intraoperative 3D-US power-Doppler angiography, rendered by current navigated 3D-US systems, clearly depicts the majority of aneurysms in the MCA aneurysm subgroup. However, future prospective studies performed on a higher number of aneurysms localized at various anatomic sites are needed to confirm our initial findings and determine their potential clinical relevance., (© 2024. The Author(s).)

Background: We aimed to develop multiple machine learning models to predict the risk of early intracranial aneurysms (IAs) rupture, evaluate and compare the performance of predictive models., Methods: Information related to patients diagnosed with IA by CT angiography and clinicians in Central hospital of Dalian University of Technology from January 2010 to June 2022 was collected, including clinical characteristics, blood indicators and IA morphological parameters. IA with rupture or maximum growth ≥ 0.5 mm within 1 month of first diagnosis was considered unstable. The relevant factors affecting IA stability were screened and predictive models were developed based on the above three levels, including random forest (RF), support vector machine (SVM), and artificial neural network (ANN). Sensitivity, specificity, accuracy and area under curve (AUC) value were used to evaluate the predictive models., Results: A total of 989 IA patients were included in the study, including 561 stable patients and 428 unstable patients. For RF models, the training set showed that sensitivity, specificity, accuracy and the AUC values were 72.8-83.7%, 76.9-86.9%, 75.1-84.1% and 0.748 (0.719-0.778)-0.839 (0.814-0.864), respectively; after test set validation, the results were 71.9-78.8%, 75.0-84.0%, 73.6-81.1% and 0.734 (0.688-0.781)-0.809 (0.768-0.850), respectively. For SVM models, the training set were 66.0-80.2%, 76.5-85.5%, 71.7-82.3%, 0.712 (0.682-0.743)-0.913 (0.884-0.924), respectively; the test set were 44.2-78.3%, 63.4-84.4%, 57.9-80.9%, 0.699 (0.651-0.747)-0.806 (0.765-0.848), respectively. For ANN models, the training set were 66.8-83.0%, 75.3-82.3%, 71.6-82.1%, 0.783 (0.757-0.808)-0.897 (0.879-0.914); the test set were 63.1-76.3%, 65.5-84.0%, 64.4-80.6%, 0.680 (0.593-0.694)-0.860 (0.821-0.899). The results of variable importance showed that age, white blood cell count (WBC) and uric acid (UA) played an important role in predicting the stability of IA., Conclusions: The predictive stability models of IA based on three artificial intelligence methods shows good clinical application. Age, WBC and UA played an important role in predicting the IA stability, and were potentially important predictors., (© 2024. The Author(s).)

Purpose: The purpose of this study is to illustrate the diagnostic and therapeutic value and clinical significance of surgical revascularization in giant aneurysms of the extracranial internal carotid artery., Methods: The research team screened a group of cases of giant aneurysms of the extracranial internal carotid artery and analyzed the detailed information of the enrolled patients in terms of their basic clinical characteristics, surgical approaches and clinical prognosis., Results: All patients had a good prognosis, except for one patient who was left with only mild facial nerve palsy (grade II facial paralysis). The results demonstrate that surgical revascularization is effective and safe in the treatment of giant aneurysms of the extracranial internal carotid artery., Conclusion: The significant conclusion of this study is to provide an ideal alternative treatment for the treatment of giant aneurysms of the extracranial internal carotid artery. The surgical revascularization technique is a powerful tool for vascular neurosurgeons in the management of complex cerebrovascular diseases when traditional surgical clipping or endovascular interventions encounter bottlenecks., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

Background: Ventral wall ICA aneurysms are a type of Paraclinoid aneurysms which arise from ventral surface of ICA opposite to the origin of the ophthalmic artery. These are technically challenging owing to its close proximity to the anterior clinoid process, difficulty in getting proximal control, difficulty in preserving ophthalmic artery and maintaining the patency of ICA., Method: A 38 year old patient with a Ventral wall ICA aneurysm by Dolenc approach., Conclusion: Tailored dural peeling and extradural anterior clinoidectomy exposes proximal part of Paraclinoid ICA allowing better proximal control and a wider exposure, which is crucial for clipping these aneurysms., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

Background: Non-ischemic cerebral enhancing (NICE) lesions have been reported as a rare complication of various neuroendovascular procedures, but information on their incidence after flow diversion is scant. It is unclear if specific devices or novel coating technologies may impact their occurrence., Methods: We conducted a multicenter study on the incidence of NICE lesions after flow diverter (FD) implantation for cerebral aneurysm treatment., Results: Eight centers identified 15 patients and provided detailed data. The clinical presentation ranged from asymptomatic to hemiplegia and cognitive impairment. The mean time to diagnosis after treatment was 65.1±101.5 days. Five centers disclosed information on all of their 1201 FD procedures during the inclusion period (2015-2022), during which 12 patients were diagnosed with NICE lesions in these institutions-that is, an incidence of 1%. FD coatings did not increase the incidence (6/591 patients (1%) treated with surface-modified FD vs 6/610 patients (1%) treated with bare FD; P=1.00). Significantly increased rates of 3.7% (6 cases in 161 procedures; P<0.01) and 3.3% (5 cases in 153 procedures; P<0.01) were found with stents of two specific product lines. The use of one product line was associated with a significantly lower incidence (0 cases in 499 procedures (0%); P<0.01)., Conclusions: Novel stent coatings are not associated with an increased incidence of NICE lesions. The incidence rate of 1% suggests that these lesions may occur more often after flow diversion than after other endovascular treatments. We found a concerning accumulation of NICE lesion cases when FDs from two product families were used., Competing Interests: Competing interests: MG: Consultancy agreements with MicroVention, Balt, phenox. Scientific advisory board of Simq. Part of the clinical event committee in a study on a flow diverter sponsored by MicroVention., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: The Neuroform Atlas Stent System is an established treatment modality for unruptured anterior and posterior circulation intracranial aneurysms. Location-specific results are needed to guide treatment decision-making. However, it is unclear whether there are differences in safety and efficacy outcomes between carotid and more distal anterior circulation aneurysms., Methods: The ATLAS IDE trial was a prospective, multicenter, single-arm, open-label interventional study that evaluated the safety and efficacy of the Neuroform Atlas Stent System. We compared differences in efficacy and safety outcomes of proximal internal carotid artery (ICA) versus distal and bifurcation anterior circulation aneurysms., Results: Of 182 cases, there were 70 aneurysms in the ICA and 112 in the distal anterior circulation (including ICA terminus/bifurcation). There were no significant differences in the primary efficacy endpoint (85.5% vs 83.9%, p=0.78) and complete aneurysm occlusion rates (88.7% vs 87.9%, p=0.78) between proximal ICA aneurysms and distal aneurysms, respectively. Complications were more often encountered in distal and bifurcation aneurysms, but the overall rate of major safety events was low and comparable between the two groups (1.4% vs 6.3%, p=0.14). Recanalization and retreatment rates were also similar between the groups., Conclusion: The results of this study suggest that the Neuroform Atlas Stent System is a safe and efficacious treatment modality for unruptured anterior circulation intracranial aneurysms, regardless of aneurysm location., Trial Registration Number: NCT02340585., Competing Interests: Competing interests: RAH is a consultant for Medtronic, Stryker, Cerenovous, Microvention, Balt, Phenox, Rapid Medical and Q’Apel, Imperative Care, Phenox, and Rapid Medical. He is on the advisory board for MiVI, eLum, Three Rivers, Shape Medical, and Corindus. He is in receipt of unrestricted research grants from the National Institutes of Health (NIH), Interline Endowment, Microvention, Stryker, CNX, and Balt. He is an investor/stockholder for InNeuroCo, Cerebrotech, eLum, Endostream, Three Rivers Medical Inc, Scientia, RisT, BlinkTBI, and Corindus. BTJ is a consultant for Stryker and a consultant/proctor for Medtronic. ES reports a speaker’s agreement with Stryker. BG is a consultant for Medtronic, Microvention, and Stryker. RGG is a consultant and receives personal fees from Cerenovus. DF reports consultant/speakers bureau for Stryker, Siemens, Penumbra, and Scientia; and serves on the SNIS board of directors. LLP is a Principal Biostatistician employed at Stryker Neurovascular and holds stock in Stryker. SWH reports core lab services for Stryker, Route 92; is an Imperative Care consultant; is a stockholder for Filtro and ThrombX; and serves on the SNIS board of directors. OOZ reports research grants from Stryker, Medtronic, Cerenovus, Penumbra, and Genentech; he is a consultant and speaker for Cerenovus, Stryker, Penumbra, and Medtronic; data safety monitoring board for Premier; has an ownership interest in Galaxy Therapeutics Inc.; and serves on SVIN committees. The other authors report no conflicts of interest., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Intracavernous carotid aneurysms (ICCAs) are rare, frequently asymptomatic, with a low rupture risk, which, however, can lead to life-threatening epistaxis. The aim of this study was to assess the effect of the treatment of asymptomatic ICCAs with flow diverters (FD) on sphenoid bone erosion or dehiscence in a selected cohort of patients., Methods: We retrospectively reviewed all asymptomatic ICCAs with sphenoid bone erosion or dehiscence detected on cone beam CT (CBCT) and treated with FD between December 2018 and December 2022. Patients were followed-up with CBCT and bone reconstruction was blindly evaluated by two interventional neuroradiologists and classified as unchanged, partial, or complete., Results: A total of 10 patients (women: 90%, mean age 58 years) treated with an FD for an asymptomatic ICCA with associated sphenoid bone erosion or dehiscence were included in this cohort. Sphenoid bone erosion was present in seven patients and dehiscence was observed in the remaining three. After treatment with FD, complete reconstruction of the sphenoid sinus wall occurred in seven cases, and partial reconstruction in two cases. Sphenoid bone erosion remained unchanged after treatment in only one patient., Conclusions: The decision to treat asymptomatic and unruptured ICCAs remains challenging due to their benign natural history and low hemorrhagic risk. The presence of sphenoid sinus erosion or dehiscence should not be overlooked since it could be considered as an indication for prophylactic treatment of life-threatening epistaxis. The mechanisms of bone erosion by the aneurysm and of reconstruction after treatment are still to be fully elucidated., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Early detection of intracranial aneurysms (IAs) is crucial for patient outcomes. Typically identified on angiographic scans such as CT angiography (CTA) or MR angiography (MRA), the sensitivity of experts in studies on small IAs (diameter <3 mm) was moderate (64-74.1% for CTAs and 70-92.8% for MRAs), and these figures could be lower in a routine clinical setting. Recent research shows that the expert level of sensitivity might be achieved using deep learning approaches., Methods: A large multisite dataset including 1054 MRA and 2174 CTA scans with expert IA annotations was collected. A novel modality-agnostic two-step IA detection approach was proposed. The first step used nnU-Net for segmenting vascular structures, with model training performed separately for each modality. In the second step, segmentations were converted to vascular surface that was parcellated by sampling point clouds and, using a PointNet++ model, each point was labeled as an aneurysm or vessel class., Results: Quantitative validation of the test data from different sites than the training data showed that the proposed approach achieved pooled sensitivity of 85% and 90% on 157 MRA scans and 1338 CTA scans, respectively, while the sensitivity for small IAs was 72% and 83%, respectively. The corresponding number of false findings per image was low at 1.54 and 1.57, and 0.4 and 0.83 on healthy subject data., Conclusions: The proposed approach achieved a state-of-the-art balance between the sensitivity and the number of false findings, matched the expert-level sensitivity to small (and other) IAs on external data, and therefore seems fit for computer-assisted detection of IAs in a clinical setting., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Aneurysm location is a key element in predicting the rupture risk of an intracranial aneurysm. A common impression suggests that pure ophthalmic aneurysms are under-represented in ruptured intracranial aneurysms (RIAs). The purpose of this study was to specifically evaluate the risk of rupture of ophthalmic aneurysms compared with other aneurysm locations., Methods: This multicenter study compared the frequency of ophthalmic aneurysms in a prospective cohort of RIAs admitted to 13 neuroradiology centers between January 2021 and March 2021, with a retrospective cohort of patients with unruptured intracranial aneurysms (UIAs) who underwent cerebral angiography at the same neuroradiology centers during the same time period., Results: 604 intracranial aneurysms were included in this study (355 UIAs and 249 RIAs; mean age 57 years (IQR 49-65); women 309/486, 64%). Mean aneurysm size was 6.0 mm (5.3 mm for UIAs, 7.0 mm for RIAs; P<0.0001). Aneurysm shape was irregular for 37% UIAs and 73% RIAs (P<0.0001). Ophthalmic aneurysms frequency was 14.9% of UIAs (second most common aneurysm location) and 1.2% of RIAs (second least common aneurysm location; OR 0.07 (95% CI 0.02 to 0.23), P<0.0001)., Conclusions: Ophthalmic aneurysms seem to have a low risk of rupture compared with other intracranial aneurysm locations. This calls for a re-evaluation of the benefit-risk balance when considering preventive treatment for ophthalmic aneurysms., Competing Interests: Competing interests: FC is a consultant for Medtronic, Balt Extrusion, Penumbra, Microvention, and Stryker; board member of Artedrone, and has stock options with Intradys and Collavidence. GM is a consultant for Stryker Neurovascular, Balt, Microvention Europe, and Sim and Cure, and has done paid lectures for Medtronic, Phenox, Johnson & Johnson, and Bracco. KJ is a consultant for Balt. AR is a consultant for Balt, Medtronic, Microvention, and Stryker. N-AS is a consultant for Balt, Medtronic Extrusion, and Microvention., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: The Pipeline Vantage Embolization Device (PEDV) is the fourth-generation pipeline flow diverter for intracranial aneurysm treatment. There are no outcome studies for the second PEDV version. We aimed to evaluate safety and efficacy outcomes. Primary and secondary objectives were to determine outcomes for unruptured and ruptured cohorts, respectively., Methods: In this multicenter retrospective and prospective study, we analyzed outcome data from eight centers using core laboratory assessments. We determined 30-day and ≥3-month mortality and morbidity rates, and 6- and 18-month radiographic aneurysm occlusion rates for procedures performed during the period July 2021-March 2023., Results: We included 121 consecutive patients with 131 aneurysms. The adequate occlusion rate for the unruptured cohort at short-term and medium-term follow up, and also for the ruptured cohort at short-term follow up, was >90%. Two aneurysms (1.5%) underwent retreatment. When mortality attributed to a palliative case in the unruptured cohort, or subarachnoid hemorrhage in the ruptured cohort, was excluded then the overall major adverse event rate in respective cohorts was 7.5% and 23.5%, with 0% mortality rates for each. When all event causes were included on an intention-to-treat basis, the major adverse event rates in respective cohorts were 8.3% and 40.9%, with 0.9% and 22.7% mortality rates., Conclusions: For unruptured aneurysm treatment, the second PEDV version appears to have a superior efficacy and similar safety profile to previous-generation PEDs. These are acceptable outcomes in this pragmatic and non-industry-sponsored study. Analysis of ruptured aneurysm outcomes is limited by cohort size. Further prospective studies, particularly for ruptured aneurysms, are needed., Competing Interests: Competing interests: Microvention core laboratory for neurointerventional study: payment to TCB. Siemens Healthineers Speakers Bureau Educational lecture on brain tumours, not related to aneurysms: payment to TCB. Medtronic Speakers Bureau Educational lecture on an independent non-industry-sponsored study published in AJNR 2019 on Pipeline Flow Diverter device: payment to TCB. Bayer Speakers Bureau Educational lecture on Explainability in AI, not related to aneurysms: payment to TCB. Consulting and proctoring agreement with Medtronic, Stryker, Balt, and Cerenovus: payment to TP. Microvention, Balt, and Medtronic support to attend meetings: payment to TM., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY. Published by BMJ.)

Background: Anterior communicating artery (ACOM) aneurysms are among the most common aneurysms associated with aneurysmal subarachnoid hemorrhage (International Study of Unruptured Intracranial Aneurysms I (N Engl J Med 339:1725-1733, 1998), Wiebers (Lancet 362:103-110, 2003)). Surgical clipping of posterior-superiorly projecting ACOM aneurysms can be challenging, as the ipsilateral A2 can interfere with clip trajectory and ACOM perforating vessels obstructed from view. Intraluminal coils can further increase the difficulty of the procedure., Method: The relevant surgical anatomy with illustration is presented. A video detailing our technique on an illustrative case is provided., Conclusion: Surgical clipping of posterior-superiorly projecting ACOM aneurysms can require complex clip configurations. We describe the key steps of posterior-superiorly projecting ACOM aneurysm clipping through a lateral supraorbital craniotomy and fenestrated tandem clipping., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

Background: Infectious endocarditis (IE) is an infectious disease caused by direct invasion of the heart valve, endocardium, or adjacent large artery endocardium by pathogenic microorganisms. Despite its relatively low incidence, it has a poor prognosis and a high mortality. Intracranial infectious aneurysms (IIA) and ruptured sinus of Valsalva aneurysm (RSVA) are rare complications of IE., Case Presentation: We report a young male patient with symptoms of respiratory tract infection, heart murmurs and other symptoms and signs. The patient also had kidney function impairment and poor response to symptomatic therapy. Blood culture was negative, but echocardiography was positive, which met the diagnostic criteria for infective endocarditis. Moreover, an echocardiography showed a ruptured sinus of Valsalva aneurysm with a ventricular septal defect. Finally, secondary rupture of an IIA with multiple organ damage led to a poor clinical outcome., Conclusion: Therefore, in the clinical setting, for young patients with unexplained fever, chest pain, or palpitations, we need to be highly vigilant, considering the possibility of infective endocarditis and promptly performing blood culture, echocardiography, cerebrovascular imaging and so on, in order to facilitate early proper diagnosis and treatment., (© 2024. The Author(s).)

Background and Purpose: The Pipeline Embolization Device is a safe and effective treatment option for intracranial aneurysms. The newer Pipeline generations have received structural refinements and a surface modification to improve deliverability, procedural safety, and angiographic outcomes. This multicenter study evaluated the clinical safety and efficacy of the 2 surface-modified Pipeline iterations, Pipeline Vantage and Pipeline Flex with Shield Technology (PFS)., Materials and Methods: Consecutive patients treated between 2017 and 2023 were retrospectively reviewed for aneurysm characteristics, procedural details, complications, and angiographic outcomes. The safety end point was the rate of procedural and postprocedural major neurologic events occurring during the hospital stay. The efficacy end point was the rate of complete occlusion at last follow-up., Results: One hundred forty-one patients underwent 112 Pipeline Vantage procedures and 32 PFS procedures for 147 aneurysms with a mean size of 8.0 (SD, 5.9) mm (11% ruptured, 16% posterior circulation, 18% nonsaccular morphology). All procedures were technically successful with a mean of 1.2 devices implanted. Balloon angioplasty was required in 20/144 (13.9%) procedures. Major neurologic adverse events occurred in 6/144 (4.2%) procedures (all ischemic stroke), resulting in death in 2 (1.4%) patients. There were no hemorrhagic complications. At a mean of 11 months, complete occlusion was achieved in 85/112 (75.9%) aneurysms, 15/112 (13.4%) had an entry remnant, and 12/112 (10.7%) had an aneurysm remnant., Conclusions: The results demonstrate high feasibility, procedural safety, and efficacy of the surface-modified Pipeline flow diverters., (© 2024 by American Journal of Neuroradiology.)

Background and Purpose: The first-generation photon-counting detector CT was recently introduced into clinical practice and represents a promising innovation in high-resolution CT imaging. The purpose of this study was to assess the image quality of ultra-high-resolution photon-counting detector CT compared with energy-integrating detector CT and to explore different reconstruction kernel sharpness levels for the evaluation of intracranial aneurysms., Materials and Methods: Ten patients with intracranial saccular aneurysms who had previously undergone conventional energy-integrating detector CT were prospectively enrolled. CT angiograms were acquired on a clinical dual-source photon-counting detector CT in ultra-high-resolution mode and reconstructed with 4 vascular kernels (Bv36, Bv40, Bv44, Bv48). Quantitative and qualitative image-quality parameters of the intracranial arteries were evaluated. For the quantitative analysis (image noise, SNR, contrast-to-noise ratio), ROIs were manually placed at standard anatomic intracranial and extracranial locations by 1 author. In addition, vessel border sharpness was evaluated quantitatively. For the qualitative analysis, 3 blinded neuroradiologists rated photon-counting detector CT and energy-integrating detector CT image quality for the evaluation of the intracranial vessels (ie, the aneurysms and 9 standard vascular branching locations) on a 5-point Likert-type scale. Additionally, readers independently selected their preferred kernel among the 4 kernels evaluated on photon-counting detector CT., Results: In terms of quantitative image quality, Bv48, the sharpest kernel, yielded increased image noise and decreased SNR and contrast-to-noise ratio parameters compared with Bv36, the smoothest kernel. Compared with energy-integrating detector CT, the Bv48 kernel offered better quantitative image quality for the evaluation of small intracranial vessels ( P < .001). Image-quality ratings of the Bv48 were superior to those of the energy-integrating detector CT and not significantly different from ratings of the B44 reconstruction kernel. When comparing side by side all 4 photon-counting detector reconstruction kernels, readers selected the B48 kernel as the best to visualize the aneurysms in 80% of cases., Conclusions: Ultra-high-resolution photon-counting detector CT provides improved image quality for neurovascular imaging. Although the less sharp kernels provided superior SNR and contrast-to-noise ratio, the sharpest kernels delivered the best subjective image quality on photon-counting detector CT for the evaluation of intracranial aneurysms., (© 2024 by American Journal of Neuroradiology.)

We investigated the clinical and radiologic predictors of unruptured symptomatic intracranial artery dissection (IAD) outcomes. Unruptured symptomatic IAD patients who underwent vessel wall magnetic resonance imaging (VW-MRI) and time-of-flight magnetic resonance angiography (TOF-MRA) within 1 month after symptom onset, followed for over 12 months were included. Baseline features predicting the clinical outcome of recurrent symptoms and radiologic outcomes of aneurysmal dilatation and occlusion were analyzed using logistic regression analysis. The Kaplan-Meier method calculated the median time to morphological stability. Patients with aneurysmal dilatation were categorized into progressive and non-progressive enlargement subgroups. Seventy-three IADs from 65 patients were included. All patients showed benign clinical course (mRS 0-1). No baseline features were predictive of recurrent symptoms. Aneurysmal dilatation was associated with increased outer diameter in baseline VW-MRI (OR, 23.15; 95% CI, 3.78-141.75, P < 0.001) and TOF-MRA (OR, 10.81; 95% CI, 2.16-53.99, P = 0.004). Occlusion was inversely associated with preserved patency in baseline VW-MRI (OR, 0.1; 95% CI, 0.01-0.74, P = 0.024) and TOF-MRA (OR, 0.14; 95% CI, 0.02-0.98; P = 0.048). The median time to morphological stability was 3.9 months (95% CI, 3.16-5.5). While baseline features did not significantly differ between aneurysmal dilatation subgroups, follow-up imaging revealed significant differences in remodeling index, normalized wall index, relative signal intensity of intramural hematoma, and presence of onion-skin appearance and intramural hematoma (all P < 0.05). Our findings suggest that while unruptured IAD presents a benign clinical outcome, follow-up imaging may be necessary to monitor the progressive enlargement of aneurysmal dilatation., (© 2024. The Author(s).)

Objective: To evaluate the performance of a semi-automated artificial intelligence (AI) software program (CerebralDoc ® system) in aneurysm detection and morphological measurement., Methods: In this study, 354 cases of computed tomographic angiography (CTA) were retrospectively collected in our hospital. Among them, 280 cases were diagnosed with aneurysms by either digital subtraction angiography (DSA) and CTA (DSA group, n = 102), or CTA-only (non-DSA group, n = 178). The presence or absence of aneurysms, as well as their location and related morphological features determined by AI were evaluated using DSA and radiologist findings. Besides, post-processing image quality from AI and radiologists were also rated and compared., Results: In the DSA group, AI achieved a sensitivity of 88.24% and an accuracy of 81.97%, whereas radiologists achieved a sensitivity of 95.10% and an accuracy of 84.43%, using DSA results as the gold standard. The AI in the non-DSA group achieved 81.46% sensitivity and 76.29% accuracy, as per the radiologists' findings. The comparison of position consistency results showed better performance under loose criteria than strict criteria. In terms of morphological characteristics, both the DSA and the non-DSA groups agreed well with the diagnostic results for neck width and maximum diameter, demonstrating excellent ICC reliability exceeding 0.80. The AI-generated images exhibited superior quality compared to the standard software for post-processing, while also demonstrating a significantly reduced processing time., Conclusions: The AI-based aneurysm detection rate demonstrates a commendable performance, while the extracted morphological parameters exhibit a remarkable consistency with those assessed by radiologists, thereby showcasing significant potential for clinical application., (© 2024. The Author(s).)

This study concentrates on the segmentation of intracranial aneurysms, a pivotal aspect of diagnosis and treatment planning. We aim to overcome the inherent instance imbalance and morphological variability by introducing a novel morphology and texture loss reweighting approach. Our innovative method involves the incorporation of tailored weights within the loss function of deep neural networks. Specifically designed to account for aneurysm size, shape, and texture, this approach strategically guides the model to focus on capturing discriminative information from imbalanced features. The study conducted extensive experimentation utilizing ADAM and RENJI TOF-MRA datasets to validate the proposed approach. The results of our experimentation demonstrate the remarkable effectiveness of the introduced methodology in improving aneurysm segmentation accuracy. By dynamically adapting to the variances present in aneurysm features, our model showcases promising outcomes for accurate diagnostic insights. The nuanced consideration of morphological and textural nuances within the loss function proves instrumental in overcoming the challenge posed by instance imbalance. In conclusion, our study presents a nuanced solution to the intricate challenge of intracranial aneurysm segmentation. The proposed morphology and texture loss reweighting approach, with its tailored weights and dynamic adaptability, proves to be instrumental in enhancing segmentation precision. The promising outcomes from our experimentation suggest the potential for accurate diagnostic insights and informed treatment strategies, marking a significant advancement in this critical domain of medical imaging., Competing Interests: Declarations. Competing Interests: The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Giant intracerebral aneurysms (GIA) comprise up to 5 % of all intracranial aneurysms. The indirect surgical strategy, which leaves the GIA untouched but reverses the blood flow by performing a bypass in combination with proximal parent artery occlusion is a useful method to achieve spontaneous aneurysm occlusion. The goal of this study was to assess the utility of computational fluid dynamics (CFD) in preoperative GIA treatment planning. We hypothesise that CFD simulations will predict treatment results. A fluid-structure interaction (FSI) CFD investigation was performed for the entire arterial brain circulation. The analyses were performed in three patient-specific CT angiogram models. The first served as the reference geometry with a C6 internal carotid artery (ICA) GIA, the second a proximal parent artery occlusion (PAO) and virtual bypass to the frontal M2 branch of the middle cerebral artery (MCA), and the third a proximal PAO in combination with a temporal M2 branch bypass. The volume of "old blood", flow residence time (FRT), dynamic viscosity and haemodynamic changes were also analysed. The "old blood" within the aneurysm in the bypass models reached 41 % after 20 cardiac cycles while in the reference model it was fully washed out. In Bypass 2 "old blood" was also observed in the main trunk of the MCA after 20 cardiac cycles. Extrapolation of the results yielded a duration of 4 years required to replace the "old blood" inside the aneurysm after bypass revascularization. In both bypass models a 7-fold increase in mean blood viscosity in the aneurysm region was noted. Bypass revascularization combined with proximal PAO favours thrombosis. Areas prone to thrombus formation, and subsequently the treatment outcomes, were accurately identified in the preoperative model. Virtual surgical operations can give a remarkable insight into haemodynamics that could support operative decision-making., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background/objective: Broad-based sidewall aneurysms of the carotid artery are primarily treated endovascularly. However, recurrence or rupture after treatment still poses a significant risk. Hence, reliable animal models mimicking this aneurysm type are essential for to evaluate the performance of new advanced endovascular devices., Methods: Experimental aneurysms were created in 12 New Zealand white rabbits (2.5-3.5 kg). The human carotid siphon was mimicked with an end-to-end anastomosis of both common carotid arteries. A venous pouch was sutured on the convexity to mimic a broad-based side wall aneurysm. Patency and configuration were investigated 4 weeks postoperatively by 3-T magnetic resonance angiography. To compare flow conditions of broad-based sidewall aneurysms in rabbits and humans, exemplary computational fluid dynamics simulations were performed using species-specific blood viscosity values., Results: We were able to achieve 0% peri- or postoperative mortality. Patency was confirmed by 3-T magnetic resonance angiography in 11 of 12 aneurysms (91.7%). Aneurysm lengths ranged from 6.4 to 9.8 mm and aneurysm necks from 7.3 to 9.8 mm. Computational fluid dynamics showed simple flow profiles with one vortex in rabbit as well as in human aneurysms. Wall shear stress rates were comparable using species-specific blood viscosity values (rabbit mean 1.65 Pa vs. human mean 1.7 Pa)., Conclusions: The broad-based curved sidewall aneurysm model mimicking the carotid siphon showed high aneurysm patency rates with low morbidity. High comparability with human flow patterns and human intranaeurysmal biomechanical forces was shown using simulations., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Purpose: Although stent-assisted technique is expected to help provide a scaffold for neointima formation at the orifice of the aneurysm, not all aneurysms treated with stent-assisted technique develop complete neointima formation. The white-collar sign (WCS) indicates neointimal tissue formation at the aneurysm neck that prevents aneurysm recanalization. The aim of this study was to explore factors related to WCS appearance after stent-assisted coil embolization of unruptured intracranial aneurysms (UIAs)., Methods: A total of 59 UIAs treated with a Neuroform Atlas stent were retrospectively analyzed. The WCS was identified on digital subtraction angiography (DSA) 1 year after coil embolization. The cohort was divided into WCS-positive and WCS-negative groups, and possible predictors of the WCS were explored using logistic regression analysis., Results: The WCS appeared in 20 aneurysms (33.9%). In the WCS-positive group, neck size was significantly smaller (4.2 (interquartile range (IQR): 3.8-4.6) versus 5.4 (IQR: 4.2-6.8) mm, p = .006), the VER was significantly higher (31.8% (IQR: 28.6%-38.4%) versus 27.6% (IQR: 23.6%-33.8%), p = .02), and the rate of RROC class 1 immediately after treatment was significantly higher (70% vs 20.5%, p < .001) than in the WCS-negative group. On multivariate analysis, neck size (odds ratio (OR): 0.542, 95% confidence interval (CI): 0.308-0.954; p = .03) and RROC class 1 immediately after treatment (OR: 6.99, 95% CI: 1.769-27.55; p = .006) were independent predictors of WCS appearance., Conclusions: Smaller neck size and complete occlusion immediately after treatment were significant factors related to WCS appearance in stent-assisted coil embolization for UIAs using the Neuroform Atlas stent., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Background and Objectives: Although the formation and rupture risk of an anterior communicating artery (ACoA) aneurysm has been the subject of many studies, no previous study has primarily searched for the relationship of the parent and daughter vessels and the impact of their size/diameter ratio on the potential rupture risk of an AcoA aneurysm. The objective of this study is to explore this link and to further analyse the surrounding vasculature of the anterior communicating artery aneurysm., Materials and Methods: We conducted a retrospective analysis of 434 patients: 284 patients with an ACoA aneurysm (121 unruptured and 162 ruptured) and 150 control patients without an ΑCoA aneurysm. Radiological angiography investigations were used to assess the diameter ratios of the parent vessels in addition to ACoA aneurysm morphology parameters., Results: When comparing the ruptured to the unruptured cases, we observed no significant difference in the parent or daughter vessel diameter ratios. Younger patient age (OR 0.96, p  = 0.00) and a higher aneurysm size ratio (OR 1.10, p  = 0.02) were of prognostic importance concerning the rupture risk of the aneurysm. The A1 diameter ratio and the A2 diameter were not statistically significant (OR 1.00, p  = 0.99, and OR 3.38, p  = 0.25 respectively)., Conclusions: In our study, we focused on asymmetry in the parent and daughter vessels as well as traditional ACoA aneurysm morphological characteristics. We were able to label younger patient age and a greater size ratio as independent prognostic factors for ACoA aneurysm rupture. We were unable to label parent and daughter vessel asymmetry as prognostic factors. To validate our findings, parent and daughter vessel asymmetry should be subjected to future prospective studies.

Three-dimensional vessel model reconstruction from patient-specific magnetic resonance angiography (MRA) images often requires some manual maneuvers. This study aimed to establish the deep learning (DL)-based method for vessel model reconstruction. Time of flight MRA of 40 patients with internal carotid artery aneurysms was prepared, and three-dimensional vessel models were constructed using the threshold and region-growing method. Using those datasets, supervised deep learning using 2D U-net was performed to reconstruct 3D vessel models. The accuracy of the DL-based vessel segmentations was assessed using 20 MRA images outside the training dataset. The dice coefficient was used as the indicator of the model accuracy, and the blood flow simulation was performed using the DL-based vessel model. The created DL model could successfully reconstruct a three-dimensional model in all 60 cases. The dice coefficient in the test dataset was 0.859. Of note, the DL-generated model proved its efficacy even for large aneurysms (> 10 mm in their diameter). The reconstructed model was feasible in performing blood flow simulation to assist clinical decision-making. Our DL-based method could successfully reconstruct a three-dimensional vessel model with moderate accuracy. Future studies are warranted to exhibit that DL-based technology can promote medical image processing., (© 2024. The Author(s).)

Aneurysms occurring along the basilar artery (BA) account for <1% of all intracranial aneurysms. Endovascular treatment (EVT) in particular is recommended for large unruptured BA aneurysms and ruptured BA aneurysms. Given that EVT techniques vary, a detailed review of EVT for BA aneurysms is necessary. In this review, the following issues were discussed: the anatomy and anomalies of the BA, the classification of BA aneurysms, the natural history of BA aneurysms, the status of open surgery, the use of EVT for various types of BA aneurysms and the deployment of new devices. According to the findings of this review and based on our experience in treating BA aneurysms, traditional coiling EVT is still the optimal therapy for most BA aneurysms. However, in some BA aneurysms, flow diverter (FD) deployment can be used. In addition, there are also some new devices, such as intrasaccular flow disruptors and stent-like devices that can be used to treat BA aneurysms. In general, EVT can yield good clinical and angiographic outcomes for patients with BA aneurysms. In addition, recent new devices and techniques, such as new-generation FDs generated via surface modification and virtual reality simulation techniques, show promise for EVT for BA aneurysms. These devices and techniques may further improve EVT outcomes for BA aneurysms., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.