Intracranial Aneurysms Research Articles

Mirror Aneurysms of the Pericallosal Artery Clipped During a Single Surgical Procedure: Case Report and Literature Review

Pericallosal artery aneurysms are rare, accounting for 2–9% of all intracranial aneurysms, and mirror aneurysms in this location are exceptionally uncommon, presenting unique surgical challenges due to their deep location and proximity to critical neurovascular structures. The aim of this case report is to describe the surgical management and successful outcome of a patient with mirror pericallosal artery aneurysms and to contribute insights into the clinical and surgical considerations for this rare condition. We report the case of a 71-year-old female with multiple cardiovascular and metabolic conditions, including hypertension and smoking—well-established risk factors for intracranial aneurysm formation and rupture. She presented with a Hunt and Hess grade II subarachnoid hemorrhage resulting in communicating internal hydrocephalus. Preoperative angiography revealed mirror aneurysms of the pericallosal artery. The patient underwent a left basal paramedian frontal craniotomy, during which a ruptured aneurysm on the right A2 segment and an unruptured aneurysm on the left A2 segment were identified. Both aneurysms were successfully clipped using curved Yasargil clips. Postoperative recovery was favorable, with no neurological deficits and stable imaging findings at a three-month follow-up. This case underscores the necessity for precise microsurgical intervention and a thorough understanding of pericallosal artery anatomy to manage such rare and challenging conditions effectively. The role of hyperlipidemia and statin use in intracranial aneurysm development remains debated and warrants further investigation. Our successful management of mirror pericallosal artery aneurysms contributes to the limited literature on this rare condition and highlights the importance of meticulous surgical techniques for favorable outcomes.

Genetically proxied liability to migraine and risk of intracranial aneurysm and subarachnoid hemorrhage.

Observational studies have reported inconsistent relationships between migraine and the risk of intracranial aneurysm and subarachnoid hemorrhage (SAH). To determine whether genetic liability to migraine is associated with risk of intracranial aneurysm and aneurysmal SAH. This study was designed as a two-sample Mendelian randomization (MR) analysis. Genetic associations with migraine were obtained from a large-scale meta-analysis of five population and clinic-based genome-wide association studies of migraine (102,084 cases and 771,257 controls of European ancestry). Genetic associations with intracranial aneurysm and SAH were obtained from a meta-analysis of 22 population-based genome-wide association studies (7495 cases and 71,934 controls of European ancestry). Findings were corroborated by sensitivity analyses and replicated in an independent sample of combined cases of intracranial aneurysm and SAH (3529 cases and 234,948 controls of Asian ancestry from the Biobank Japan and China Kadoorie Biobanks). In secondary analyses, we investigated the outcomes of extracranial aneurysm in the FinnGen and UK Biobank cohorts (up to 7466 combined cases of thoracic and abdominal aortic aneurysm). Genetic liability to migraine was associated with increased risk of the combined outcome of unruptured intracranial aneurysm and SAH (odds ratio [OR] of outcome per doubling in migraine liability 1.19, 95% confidence interval [CI] 1.06-1.35; p = 0.005). This finding was replicated in an independent sample (OR 1.15, 95% CI 1.02-1.30; p = 0.027), and there were similar associations across the component outcomes of unruptured intracranial aneurysm (OR 1.20, 95% CI 1.01-1.42; p = 0.035) and SAH (OR 1.18, 95% 1.04-1.33; p = 0.008). These findings were consistent in sensitivity analyses robust to violations of the MR assumptions. In reverse MR analyses, genetic liability to intracranial aneurysm was not associated with migraine (OR 1.03, 95% CI 0.99-1.07; p = 0.141). In a secondary analysis, there were similar associations of genetic liability to migraine with all forms of aortic aneurysm (OR for combined thoracic and aortic aneurysm 1.18, 95% CI 1.10-1.27; p = 8.49 × 10-6). Genetic liability to migraine was associated with increased risk of intracranial and extracranial aneurysms, supporting a causal relationship between liability to migraine and these traits. Further work is needed to identify the biological mechanisms and clinical relevance of these findings.

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

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

Differences in internal carotid artery tortuosity in ruptured and unruptured anterior circulation aneurysms. A matched case-control study

ObjectiveTortuosity of the internal carotid artery is believed to contribute to the formation of intracranial aneurysms, although there is scant literature on its role as a risk factor for rupture specifically. Therefore, this study investigated the influence of cervical internal carotid artery (cICA) tortuosity on rupture of aneurysms of the anterior cerebral circulation. MethodsAngiographic imaging studies from patients who underwent endovascular embolisation for anterior circulation aneurysms at a tertiary centre were identified. 83 patients with a history of aneurysmal rupture and subarachnoid haemorrhage (SAH group) were matched for age, aneurysm location and size, history of subarachnoid haemorrhage and hypertension to 83 subjects with unruptured aneurysms (control group). cICA tortuosity was assessed utilising subjective (kinks, loops or coils) and objective (tortuosity index) parameters. ResultsSubjective cICA tortuosity was identified in 33.7% and 56.6% of patients in the SAH and control groups respectively (OR 0.39 [95% CI 0.21–0.75]). Objective cICA tortuosity was present in 35.7% and 46.8% of SAH and control patients (OR 0.63 [95% CI 0.32–1.27]). OR values are suggestive of cICA tortuosity as a negative predictor of aneurysmal rupture, with more predictive power attributed to the subjective assessment, despite the limited statistical significance of the objective results. ConclusionsThis study demonstrated an increased presence of cICA tortuosity in unruptured aneurysms compared to ruptured aneurysms, suggesting it is unlikely to represent a risk factor for rupture. Further research in the form of longitudinal observational studies of untreated aneurysms would aid in investigating cICA tortuosity as a protective factor.

Advancements in Brain Aneurysm Management: Integrating Neuroanatomy, Physiopathology, and Neurosurgical Techniques

Brain aneurysms, characterized by abnormal bulging in blood vessels, pose significant risks if ruptured, necessitating precise neuroanatomical knowledge and advanced neurosurgical techniques for effective management. This article delves into the intricate neuroanatomy relevant to brain aneurysms, including the vascular structures and critical regions involved. It provides a comprehensive overview of the pathophysiology of aneurysm formation and progression. The discussion extends to modern neurosurgical approaches for treating brain aneurysms, such as microsurgical clipping, endovascular coiling, and flow diversion techniques. Emphasis is placed on preoperative planning, intraoperative navigation, and postoperative care, highlighting the importance of a multidisciplinary approach. By integrating neuroanatomical insights with cutting-edge surgical practices, this article aims to enhance the understanding and treatment outcomes of brain aneurysms.

Therapeutic Effect of Targeted Deployment Filling Coils in the Treatment of Intracranial Aneurysms.

Endovascular coil embolization is the primary therapeutic modality for intracranial aneurysms. Substantial reports have been found regarding the coil packing density and inflow jet. However, the hemodynamic effect of increasing the rate of tamponade in the inflow jet area within the aneurysm remains unclear. In this study, individualized geometries of six intracranial aneurysms were recruited: all six aneurysms were located in the internal carotid artery. Two groups were created by changing the position and orientation of the microcatheter for the release of the third segment of the filling coil. The finite element method was used to simulate coil deployment. Computational fluid dynamics was used to characterize hemodynamics in post-deployment aneurysms. The parameters evaluated included velocity reduction, wall shear stress (WSS), low WSS (LWSS), relative residence time (RRT), flow kinetic energy in the neck region of the aneurysms, and residual flow volume (RFV) in the aneurysms. At the peak time (t = 0.17 s), the targeted deployment group has similar proportion of LWSS area to conventional deployment groups: targeted 78.13% ± 34.59% versus normal 74.20% ± 36.94% (mean ± SD, p = 0.583). The targeted deployment group has a higher RRT area (targeted 16.84% ± 5.58% vs. normal 6.42% ± 5.67% [mean ± SD, p = 0.009]), smaller flow kinetic energy (targeted 9.43 ± 4.33 vs. normal 16.23 ± 5.92 [mean ± SD, p = 0.047]), and a larger RFV in the aneurysms (targeted 35.97 ± 24.35 mm3 vs. normal 25.80 ± 18.94 mm3 [mean ± SD, p = 0.44]). Inflow jets play an important role in the treatment of aneurysms, and deploying filling coils in accordance with inflow jets may result in a better hemodynamic environment.

Integrated Deep Learning Model for the Detection, Segmentation, and Morphologic Analysis of Intracranial Aneurysms Using CT Angiography.

"Just Accepted" papers have undergone full peer review and have been accepted for publication in Radiology: Artificial Intelligence. This article will undergo copyediting, layout, and proof review before it is published in its final version. Please note that during production of the final copyedited article, errors may be discovered which could affect the content. Purpose To develop a deep learning model for the morphologic measurement of unruptured intracranial aneurysms (UIAs) based on CT angiography (CTA) data and validate its performance using a multicenter dataset. Materials and Methods In this retrospective study, patients with CTA examinations, including those with and without UIAs, in a tertiary referral hospital from February 2018 to February 2021 were included as the training dataset. Patients with UIAs who underwent CTA at multiple centers between April 2021 to December 2022 were included as the multicenter external testing set. An integrated deep-learning (IDL) model was developed for UIA detection, segmentation and morphologic measurement using an nnU-net algorithm. Model performance was evaluated using the Dice similarity coefficient (DSC) and intraclass correlation coefficient (ICC), with measurements by senior radiologists serving as the reference standard. The ability of the IDL model to improve performance of junior radiologists in measuring morphologic UIA features was assessed. Results The study included 1182 patients with UIAs and 578 controls without UIAs as the training dataset (55 years [IQR, 47-62], 1,012 [57.5%] females) and 535 patients with UIAs as the multicenter external testing set (57 years [IQR, 50-63], 353 [66.0%] females). The IDL model achieved 97% accuracy in detecting UIAs and achieved a DSC of 0.90 (95%CI, 0.88-0.92) for UIA segmentation. Model-based morphologic measurements showed good agreement with reference standard measurements (all ICCs > 0.85). Within the multicenter external testing set, the IDL model also showed agreement with reference standard measurements (all ICCs > 0.80). Junior radiologists assisted by the IDL model showed significantly improved performance in measuring UIA size (ICC improved from 0.88 [0.80-0.92] to 0.96 [0.92-0.97], P < .001). Conclusion The developed integrated deep learning model using CTA data showed good performance in UIA detection, segmentation and morphologic measurement and may be used to assist less experienced radiologists in morphologic analysis of UIAs. ©RSNA, 2024.

Numerical simulation of individualized flow diversion cerebral aneurysms treatment

AbstractFlow diverter implantation has emerged as a highly effective treatment for cerebral aneurysms. However, the variability in patient‐specific vascular anatomy necessitates detailed pre‐operative planning to mitigate potential complications arising from standard, one‐size‐fits‐all devices. To address these challenges, robust predictive simulation tools are essential for optimizing flow diverter design and implantation strategies tailored to the unique characteristics of each patient's anatomy. This study focuses on developing an advanced numerical simulation tool for modeling the mechanical behavior of braided flow diverters during crimping and navigation through patient‐specific vasculature. Using isogeometric analysis (IGA) with NURBS‐based representations in LS‐Dyna, the intricate deformations of the flow diverter wires during catheter crimping are captured with high accuracy. The patient‐specific vessel geometries, derived from imaging data, are integrated into the model to account for variations in vascular structure, ensuring precise alignment and controlled navigation of the device. The navigation process relies on optimizing the central axis of the blood vessel to minimize torsional stress on the flow diverter, reducing the risk of device malfunction or failure during deployment. By incorporating patient‐specific information, such as vessel curvature and tortuosity, the simulation tool enables the prediction of potential issues, thus allowing for intervention planning that is tailored to individual anatomy. This patient‐specific approach enhances the safety and efficacy of flow diverter implantation and serves as a foundation for improved device design prior to prototype development.

Blockade of the Platelet-Driven CXCL7-CXCR1/2 Inflammatory Axis Prevents Murine Cerebral Aneurysm Formation and Rupture.

Platelet aggregation is intimately associated with vascular inflammation and is commonly seen on routine histology studies of cerebral aneurysms. Platelets, when activated, have been shown to augment neutrophil response and the pro-inflammatory cascade. Platelet-neutrophil complexes have been found to aggravate atherosclerosis through a positive feedback loop. We hypothesized that targeting platelet aggregation and downstream inflammation could be used to prevent aneurysm formation and progression. First, we induced cerebral aneurysm formation in a previously described intracranial aneurysm model via carotid artery ligation, hypertension, and stereotactic elastase injection in C57BL/6 mice and analyzed vessels for lesion and thrombus formation. Raybiotech cytokine arrays were used to analyze 96 cytokines in induced murine aneurysms and 120 cytokines in human tissue samples. Cerebral aneurysm formation and inflammatory pathway were then studied in animals treated with IgG2 antibody (control), anti-GpIb antibody (platelet depletion), 1:10 DMSO:PBS (control), clopidogrel, anti-CXCR1/2 small molecule inhibitor, or anti-CXCL7 antibody. Bleeding assays and flow cytometry were used to evaluate platelet function in treated groups. CD31 + platelet aggregates are a common feature in human and mouse cerebral aneurysm specimens. Platelet ablation in mice prevents cerebral aneurysm formation (20% vs 100% in control antibody-treated mice, n = 5 each, p = 0.0476). Mice treated with 1mg/kg clopidogrel develop significantly less aneurysms than controls (18% vs 73%, n = 11 and 11, respectively, p = 0.03). Semi-quantitative analysis of 96 different cytokines using Raybiotech arrays shows increased protein expression of CXCL7 in murine cerebral aneurysms when compared to controls. Treatment with clopidogrel results in reciprocal decrease in detected CXCL7. Targeting CXCL7-CXCR1/2 axis with 10mg/kg reparixin (CXCR1/2 antagonist) significantly decreases cerebral aneurysm formation (11% vs 73%, n = 9 and 11, p = 0.0098) while treatment with 10mg/kg SB225002 tends to decrease aneurysm formation (36% vs 73%, n = 11 vs n = 7, p = 0.11). Lastly, specific antibody blockade against CXCL7 using anti-CXCL7 antibody at 100 ug/mL significantly decreases cerebral aneurysm formation (29% vs 75%, n = 7 vs n = 8, p = 0.046). Platelet inflammation has an important role in cerebral aneurysm formation. Small molecule inhibitors targeting platelet CXCL7-CXCR1/2 inflammatory axis could be used to prevent cerebral aneurysm formation or progression.

Cerebral Aneurysm: Filling the Gap Between Pathophysiology and Nanocarriers

Intracranial aneurysms, characterized by abnormal dilations of cerebral arteries, pose significant health risks due to their potential to rupture, leading to subarachnoid hemorrhage with high mortality and morbidity rates. This paper aim is to explore the innovative application of nanoparticles in treating intracranial aneurysms, offering a promising avenue for enhancing current therapeutic strategies. We took into consideration the pathophysiology of cerebral aneurysms, focusing on the role of hemodynamic stress, endothelial dysfunction, and inflammation in their development and progression. By comparing cerebral aneurysms with other types, such as aortic aneurysms, we identify pathophysiological similarities and differences that could guide the adaptation of treatment approaches. The review highlights the potential of nanoparticles to improve drug delivery, targeting, and efficacy while minimizing side effects. We discuss various nanocarriers, including liposomes and polymeric nanoparticles, and their roles in overcoming biological barriers and enhancing therapeutic outcomes. Additionally, we discuss the potential of specific compounds, such as Edaravone and Tanshinone IIA, when used in conjunction with nanocarriers, to provide neuroprotective and anti-inflammatory benefits. By extrapolating insights from studies on aortic aneurysms, new research directions and therapeutic strategies for cerebral aneurysms are proposed. This interdisciplinary approach underscores the potential of nanoparticles to positively influence the management of intracranial aneurysms, paving the way for personalized treatment options that could significantly improve patient outcomes.

Modeling Fibrin Accumulation on Flow-Diverting Devices for Intracranial Aneurysms.

The mechanisms leading to aneurysm occlusion after treatment with flow-diverting devices are not fully understood. Flow modification induces thrombus formation within the aneurysm cavity, but fibrin can simultaneously accumulate and cover the device scaffold, leading to further flow modification. However, the interplay and relative importance of these processes are not clearly understood. A computational model of fibrin accumulation and flow modification after flow diversion treatment of cerebral aneurysms has been developed under the guidance of invitro experiments and observations. The model is based on the loose coupling of flow and transport-reaction equations that are solved separately by independent codes. Interaction or reactive terms account for thrombin production from prothrombin stimulated by thrombogenic metallic wires and inhibition by antithrombin as well as fibrin production from fibrinogen stimulated by thrombin and flow shear stress, and fibrin adhesion to device wires and already attached fibrin. The computational model was demonstrated and tested on idealized vessel and aneurysm geometries. The model was able to reproduce the salient features of fibrin accumulation after the deployment of flow-diverting devices in idealized invitro models of cerebral aneurysms. Namely, fibrin production in regions of high shear stress, initial accumulation at the inflow zone, and progressive occlusion of the device and corresponding flow attenuation. The computational model linking flow dynamics to fibrin production, transport, and adhesion can be used to investigate and better understand the effects that lead to fibrin accumulation and the resulting aneurysm inflow reduction and intra-aneurysmal flow modulation.

Strategic Dual Approach for the Management of a Symptomatic Giant Partially Thrombosed Aneurysm at the Basilar Tip - Integrating Intrasaccular Flow Diversion and Endovascular Flow Reversal.

Managing giant partially thrombosed intracranial aneurysms presents significant challenges due to their unfavorable natural history and the lack of standardized treatment approaches. Conventional treatments, whether open surgical or endovascular, often struggle to manage these aneurysms effectively, resulting in high recurrence rates or significant morbidity. The patient was a 62-year-old male with a symptomatic giant partially thrombosed aneurysm at the tip of the basilar artery, presenting with left-sided hemiparesis and dysarthria. Diagnostic imaging revealed a giant aneurysm with a wide-necked, canalized portion. A two-stage endovascular treatment was conducted, involving a balloon occlusion test (BOT) and intraoperative monitoring (IOM) for maximum patient safety. The treatment utilized stent-assisted Woven EndoBridge (WEB) embolization and serial bilateral vertebral artery trapping. The procedure successfully isolated the aneurysm and postoperative imaging confirmed the absence of recanalization, preserving the intact posterior circulation. The patient showed stable recovery and no neurological deficits during the 12-month follow-up period. This technical note demonstrates the feasibility and efficacy of strategically integrating intrasaccular flow diversion using a WEB device and flow reversal through bilateral vertebral artery trapping for treating giant partially thrombosed aneurysms.

The MARVIN Hypothesis: Linking Unhealthy Lifestyles to Intracranial Aneurysm Rupture Risk and Clinical Prognosis

Background and Objectives: The rising incidence of modifiable lifestyle risk factors and cardiovascular diseases, driven by poor diet, inactivity, excessive alcohol use, and smoking, may influence the development and rupture of intracranial aneurysms (IA). This study aimed to examine the impact of lifestyle-related and cardiovascular risk factors on IA rupture and patient outcomes. Materials and Methods: We developed the “MARVIN” (Metabolic and Adverse Risk Factors and Vices Influencing Intracranial Aneurysms) model and conducted a retrospective analysis of 303 patients with 517 IAs, treated between 2007 and 2020. Of these, 225 patients were analyzed for rupture status and 221 for clinical outcomes. The analysis focused on hypertension, diabetes, hypercholesterolemia, vascular diseases, nicotine and alcohol abuse, obesity, aneurysm rupture status, and clinical outcomes. Logistic regression was used to evaluate the impact of these risk factors. Results: Among those with risk factors, 24.9% (56/225) and 25.3% (56/221) had one, 32.0% (72/225) and 30.8% (68/221) had two, 20.0% (45/225) and 20.4% (45/221) had three, 12.0% (27/225) and 12.2% (27/221) had four, 4.0% (9/225) and 4.1% (9/221) had five, 0.9% (2/225) had six in both groups, and 0.4% (1/225) and 0.5% (1/221) had seven risk factors, respectively. Strong relationships were found between lifestyle-related vascular risk factors, indicating multiple comorbidities in patients with unhealthy habits. Smokers with ruptured aneurysms had higher WFNS (World Federation of Neurosurgical Societies) scores, but nicotine abuse did not affect long-term outcomes. The most significant predictors for poor outcomes were WFNS score and age, while age and a history of vascular diseases were protective against rupture. Despite the high prevalence of modifiable risk factors, they did not significantly influence rupture risk. Conclusions: The findings suggest a need for multifactorial risk assessment strategies in managing IA patients. Future studies with larger cohorts are required to confirm these results and better understand IA progression.

Inverse Association between the Body Mass Index and the Incidence of Unruptured Intracranial Aneurysms-Insights from the Hamburg City Health Population Study.

Overweight/obese patients experience a lower incidence of subarachnoid hemorrhage (SAH) compared to non-overweight patients, even though elevated body mass index (BMI) has been associated with various SAH risk factors. Given that intracranial aneurysms are a primary cause of SAH, a potential protective effect of a high BMI on intracranial aneurysms is likely but remains insufficiently investigated. This population-based MRI study aims to conduct detailed analyses on risk factors associated with the incidence of unruptured intracranial aneurysms (UIA). Retrospective analysis of subjects enrolled in the prospective Hamburg City Health study who underwent intracranial magnetic resonance imaging (MRI) was done. MRI scans were screened for UIA using time-of-flight angiography. Subject data including medical history, laboratory examinations, and risk factors for UIA were collected, and a multivariable logistic regression model was used to investigate the relationship between risk factors and UIA incidence. 2688 subjects (mean (IQR) age, 65 (58-71); 1176 female (43.8%) were included. An UIA was detected in 214 subjects with an incidence of 10.6% (6.0%) in females (males). Determinants for UIA were female sex (OR 2.00, 95%CI 1.45-2.77, p < 0.001), hypertension (OR 1.48, 95%CI 1.08-2.04, p = 0.015), smoking (OR 1.41, 95%CI 1.03-1.95, p = 0.036), and BMI (OR 0.95, 95%CI 0.91-0.98, p = 0.004). Among subjects with UIA, 9.4% with a BMI > 25 had multiple aneurysms, compared to 21.6% with BMI ≤ 25 (p = 0.012). This study suggests that a high BMI exhibits a protective effect on UIA incidence and the development of multiple aneurysms. Additionally, the data confirms established risk factors for UIA development, such as female sex, hypertension, and smoking.

Branching and nonbranching intracranial aneurysms in the presence of a persistent stapedial artery and an aberrant internal carotid artery assessed with computational hemodynamics: illustrative case.

The mechanisms underlying the initiation and progression of bifurcation versus lateral wall aneurysms are not well understood. Computational fluid dynamics (CFD) can improve the understanding of these mechanisms and can consequently help identify patients at higher risk for developing aneurysms and monitor them more closely. A 36-year-old man presented with a ruptured anterior communicating artery aneurysm, which was successfully treated with microsurgical clipping. Imaging also revealed a persistent stapedial artery with an elongated and tortuous posterior communicating artery (PComA). Fourteen years later, he was readmitted for a ruptured aneurysm on a PComA loop. CFD helped identify considerable collateral circulation due to the aberrant internal carotid artery (ICA). High flow rates trigger both types of aneurysms, but nuances exist in the hemodynamic mechanisms that drive their growth. Berry aneurysms and lateral wall aneurysms initially start due to a high flow rate, a common underlying cause. However, the formation of true sidewall aneurysms is primarily characterized by locally increased wall shear stress, while the development of berry aneurysms is mainly linked to high local blood pressure at arterial bifurcations. An aberrant ICA can lead to supraphysiological compensatory flow in the anterior and posterior circulation, increasing the risk of intracranial aneurysm formation at both branching and nonbranching sites, underscoring the need for lifelong monitoring. https://thejns.org/doi/10.3171/CASE24421.

Efficacy and safety of the contralateral approach to vascular lesions in the vertebral artery: patient series.

Endovascular treatment is preferred over microsurgical clipping for intracranial aneurysms in the posterior circulation. However, access to lesions, particularly those in the regions of the vertebral artery (VA) and the posterior inferior cerebellar artery (PICA), is technically challenging in terms of the vessel diameter of the ipsilateral VA or the branching angle of the PICA. Nine cases of intracranial aneurysms in the region of the PICA, which were endovascularly treated with an approach beyond the vertebrobasilar junction (VBJ) from the contralateral VA in the last 4 years, are described herein. All procedures, namely stent deployment, the use of a balloon catheter, and coiling, were safely performed using the contralateral approach. Neither rebleeding nor ischemic complications occurred. All patients had favorable outcomes and no recurrence. All aneurysms were successfully treated using an adjunctive technique with an additional approach beyond the VBJ from the contralateral VA. The combination of both ipsilateral and contralateral approaches to VA-PICA or PICA lesions contributes to safe and effective endovascular treatment. https://thejns.org/doi/10.3171/CASE24420.

How I do It: High flow EC-IC bypass for complex middle cerebral artery aneurysms using the lateral circumflex femoral artery as interposition graft.

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. We present our technique and experience harvesting the lateral circumflex femoral artery as an alternative graft vessel for high-flow bypasses. The lateral circumflex femoral artery is easy to harvest and is a reliable graft vessel for high-flow bypasses for complex aneurysms.

Uncovering SPP1+ Macrophage, Neutrophils and Their Related Diagnostic Biomarkers in Intracranial Aneurysm and Subarachnoid Hemorrhage.

Intracranial aneurysms (IA) frequently cause subarachnoid hemorrhage (SAH) and have poor prognosis. However, the molecular mechanisms and diagnostic biomarkers associated with IA and ruptured IA (rIA) remain poorly understood. In this study, single-cell and transcriptome datasets were obtained from the GEO database. The cell populations were annotated to identify potential pathogenic subpopulations, followed by intercellular communication, pseudotime, and SCENIC analyses. Proteome-wide and transcriptome-wide Mendelian randomization (MR) analyses were conducted to identify risk factors for IA and SAH. The major pathological changes and diagnostic biomarkers of IA and SAH were identified based on the transcriptome datasets. A clinical cohort was established to identify the diagnostic biomarkers and validate the results. Macrophages and neutrophils were predominantly increased in IA and rIA tissues, and neutrophils were markedly upregulated in the blood of SAH patients. SPP1+ Macrophage was progressively elevated in aneurysms, promoting vascular smooth muscle cell (VSMC) phenotypic transformation and collagen matrix remodeling through the SPP1 and TGF-β pathways. Furthermore, HIF1α regulon was enriched in SPP1+ Macrophage, mediating inflammation and metabolic reprogramming, which contributed to IA progression. Integrated MR analysis identified CD36 as a risk factor for both IA and SAH, and it has been recognized as an effective blood biomarker for SAH. Neutrophils and their related indicators have emerged as excellent biomarkers of SAH in clinical cohorts. This study highlighted the detrimental role of SPP1+ Macrophage in IA and SAH using single-cell sequencing and MR analyses. CD36 was identified as a risk factor for IA and SAH and was also an efficient blood biomarker for SAH. In a clinical cohort, neutrophils and related indicators were valuable for the early diagnosis of SAH.

Enhanced Preoperative Planning for Intracranial Aneurysms Through Multimodal Image Fusion of Silent/Time-of-Magnetic Resonance Angiography and Computed Tomography Using 3DSlicer: A Comparative Efficacy Analysis With Computed Tomography Angiography.

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. 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. 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). 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.

A Novel Landmark-based Semi-supervised Deep Learning Method for Cerebral Aneurysm Detection Using TOF-MRA

Background: Time-of-flight (TOF) magnetic resonance angiography (MRA) is widely used to identify aneurysm in human brain. Various deep learning models have been developed to help TOF-MRA reading in the field. The performance of those TOF-MRA analysis tools, however, faces several limitations in cerebral aneurysm detection. These challenges primarily come from the fact that cerebral aneurysms occupy less than 0.1% of the total TOF-MRA voxel size. This study aims to improve the efficiency of cerebral aneurysm detection by developing a landmark-based semi-supervised deep learning method, a technology that automatically generates landmark boxes in areas with a high probability of cerebral aneurysm occurrence.Methods: We used data from a total of 500 aneurysm-positive and 50 aneurysm-negative subjects. The aneurysm detection model was developed using clustering and a dilated residual network.Results: When the number of landmarks was ten and their size was 36 mm&lt;sup&gt;3&lt;/sup&gt;, the best performance was achieved in our experiment. Although landmark occupies a small portion of the entire image, up to 98.2% of landmarks were cerebral aneurysms. The sensitivity of the model for cerebral aneurysm detection was 83.0%, with a false positive rate of 3.4%.Conclusions: This study developed a deep learning model using TOF-MRA image. This model generates the most suitable landmarks for each individual, excluding unnecessary areas for cerebral aneurysm detection, which makes it possible to focus on areas with a high probability of occurrence. This model is expected to enhance the efficiency and accuracy of cerebral aneurysm detection in the field.