Search Results (65)

Background/Objectives: Intracranial aneurysm (IA) management has evolved from surgical treatment of ruptured lesions into a multidisciplinary field integrating diagnostics, neurocritical care, endovascular techniques, and individualized risk assessment. As the literature has grown beyond the scope of traditional narrative synthesis, bibliometric methods are needed to characterize the field’s development. We used co-word analysis to map the conceptual structure and thematic evolution of IA research over nearly eight decades. Methods: We analyzed 22,061 publications indexed in PubMed between 1946 and 2023. Co-word analysis of Medical Subject Headings tracked thematic development across six subperiods grouped into eras. Within each thematic network, topics were classified by centrality and density as motor, niche (highly developed but isolated), emerging or declining, or basic themes. Results: Four historical eras were delineated as an interpretative synthesis of the six subperiods. The open-surgery era (1946–1980) centered on ruptured aneurysms and refinement of operative techniques. The transitional era (1981–1990) was marked by proactive vasospasm management and emerging neurocritical care. The endovascular era (1991–2010) reflected the rise of evidence-based medicine and endovascular therapy. The multidisciplinary era (2011–2023) shifted toward unruptured aneurysms, molecular research, biomechanics, and individualized risk stratification. Recent themes, including hemodynamics, flow diversion, and precision medicine, reflect a growing research emphasis on predictive and personalized approaches to aneurysm management. Conclusions: IA research has evolved from descriptive, technique-oriented studies toward a data-driven landscape increasingly focused on predictive assessment and management of unruptured lesions. Its thematic evolution highlights the growing prominence of molecular and computational approaches, although their clinical and translational impact cannot be directly inferred from the present analysis. Full article

Background: Unruptured intracranial aneurysms (UIAs) represent a major challenge in neurosurgical practice. Rupture risk assessment traditionally relies on qualitative parameters, such as aneurysm size and shape, combined with surgical judgment and clinical expertise. However, these approaches may fail to account for the complex interplay between vascular morphology and hemodynamic forces that leads to aneurysm growth and rupture. Therefore, the development of reliable and quantitative parameters is essential to support neurosurgeons in balancing the risks of intervention against the natural history of the disease, thus optimizing decision-making for surgery. Methods: We developed an integrative framework based on a novel morphological parameter (MP), integrating multiple geometric descriptors into a single quantifiable index. To complement morphological assessment, patient-specific computational fluid dynamics (CFD) simulations were performed to evaluate hemodynamic factors known to influence aneurysm progression, thus analyzing structural and flow-related determinants of rupture risk. Results: In a cohort of 60 consecutive patients with MCA UIAs, MP showed strong concordance with the treatment decision made by an expert neurosurgeon regarding the indication for surgical clipping of aneurysms considered at risk of imminent rupture, providing an indirect, objective measure of UIA rupture risk stratification. CFD analyses confirmed that adverse hemodynamic conditions, including elevated intra-aneurysmal pressures and heterogeneous distribution of wall shear stress, correlated with unfavorable morphological features that were considered to indicate a higher risk of rupture by an expert neurosurgeon. Moreover, the integration of expert clinical judgment with quantitative indices may enhance the discrimination between aneurysms requiring early surgical intervention and those suitable for conservative management. Conclusions: This proof-of-concept study highlights the potential added value of combining morphological modelling and patient-specific hemodynamic analysis to support, rather than replace, expert neurosurgical judgment regarding the surgical management of unruptured MCA aneurysms. The proposed parameter (MP) shows concordance with expert operability decisions and may complement current neurosurgical evaluation as an ancillary decision-support tool, potentially contributing to safer operative strategies, more individualized patient management, and ultimately improved patient outcomes in the treatment of unruptured intracranial aneurysms. Full article

Background: Maintaining hemodynamic stability is crucial during coil embolization of unruptured intracranial aneurysms. Remimazolam has been suggested to exert less cardiovascular depression than propofol and may therefore provide more stable hemodynamic conditions. This study compared the hemodynamic effects of remimazolam and propofol when used for anesthesia induction and maintenance in patients undergoing coil embolization with I-gel airway management. Methods: In this single-center, randomized study, adults undergoing elective coil embolization for unruptured intracranial aneurysms were assigned to remimazolam or propofol induction followed by I-gel insertion. The primary outcome was the peak-to-nadir systolic blood pressure difference during the peri-induction period. Secondary outcomes included the peak-to-nadir mean arterial pressure difference, lowest systolic and mean arterial pressures, the incidence of hypotension, vasoactive drug requirements, and recovery outcomes. Results: Of the 50 patients randomized, 46 were included in the analysis, including 22 in the remimazolam group and 24 in the propofol group. The peri-induction peak-to-nadir systolic blood pressure difference was smaller with remimazolam than with propofol (38.2 ± 13.2 vs. 51.7 ± 13.4 mmHg, p = 0.001). The peak-to-nadir mean arterial pressure difference was also smaller, while the lowest systolic and mean arterial pressures were higher, with remimazolam. The incidence of hypotension was lower with remimazolam (40.9% vs. 87.5%, p = 0.002), with correspondingly lower requirements for ephedrine and norepinephrine. Conclusions: Remimazolam-based anesthesia was associated with a smaller peri-induction peak-to-nadir systolic blood pressure difference, a lower incidence of hypotension, and less frequent vasoactive drug use than propofol during I-gel-facilitated anesthesia for unruptured intracranial aneurysm coil embolization. These findings suggest a favorable hemodynamic profile in this setting and support further evaluation in larger trials. Full article

Intracranial aneurysm rupture is a major cause of hemorrhagic stroke and a significant contributor to human mortality. With the emergence of artificial intelligence (AI), particularly machine learning (ML) and deep learning (DL), a series of new approaches have been introduced to improve aneurysm detection, rupture assessment, risk prediction, and prognosis evaluation. This narrative review synthesizes the findings from 21 peer-reviewed studies identified through searches in PubMed, Scopus, Web of Science, and IEEE Xplore, covering the period from June to September 2025. The reviewed studies examined the use of AI for aneurysm detection, rupture assessment and risk prediction, and prognosis evaluation based on clinical, morphological, radiomic, and hemodynamic data. The reviewed studies applied different AI approaches, including conventional ML algorithms, convolutional neural networks, transformer-based models, radiomics, and multimodal models. Several studies reported encouraging performance in aneurysm detection, segmentation, rupture assessment, and prognosis evaluation, while some approaches showed better performance compared with traditional clinical scoring systems. However, important limitations remain, including the frequent use of small or single-center datasets, limited external validation, and heterogeneity in imaging protocols and feature-extraction methods. AI is showing strong potential in supporting the management of intracranial aneurysms. However, further research is needed, particularly through multicenter and external validation, improved model explainability and robustness, and better integration of these systems into clinical workflows. Full article

Background/Objectives: Clazosentan reduces cerebral vasospasm and delayed cerebral ischemia following aneurysmal subarachnoid hemorrhage (aSAH). However, concerns that clazosentan may cause cerebral edema and increase intracranial pressure (ICP) have discouraged its use in patients with poor-grade aSAH. Methods: This single-center retrospective study included 59 patients with aSAH who underwent continuous direct ICP monitoring, of whom 23 received clazosentan and 24 received fasudil. Most clazosentan-treated patients had poor-grade aSAH (WFNS 4–5, 95.7%). The primary outcome was the change in mean daily ICP in the clazosentan group between the pre-treatment and full treatment periods, with a secondary analysis restricted to the first 7 days and stratified by the presence of intracerebral hematoma (ICH). Cerebral perfusion pressure (CPP) changes were assessed as secondary outcomes, and the fasudil group served as an exploratory comparator. Results: Among 21 clazosentan-treated patients available for primary analysis, median ICP did not change significantly between the pre-treatment and treatment periods (6.4 vs. 8.4 mmHg; median ΔICP +0.5 mmHg, 95% CI −1.74 to +2.64; p = 0.708), a finding consistent in the first 7 days and across subgroups by ICH status. In contrast, CPP increased significantly between the pre-treatment and treatment periods (69.1 vs. 84.5 mmHg; median ΔCPP +14.0 mmHg, 95% CI +8.93 to +17.44; p < 0.001). Conclusions: In this retrospective single-center cohort, no statistically significant ICP elevation was observed during clazosentan administration under standard neurosurgical management. Although the small sample size limits statistical power and a false-negative result cannot be excluded, these findings may help inform clinical decision-making regarding clazosentan use in patients with poor-grade aSAH. Full article

Background/Objectives: Flow diverter stents are widely used for the treatment of complex, unruptured intracranial aneurysms. Nitinol-based devices offer improved flexibility and vessel conformability; however, real-world clinical outcome data remain limited. This study aimed to evaluate the safety and clinical outcomes of nitinol-based flow diverter stents in a single-center cohort. We hypothesized that these devices would demonstrate high technical success rates, low rates of device-related complications, and favorable functional outcomes at 6 months. Methods: We retrospectively analyzed 109 patients with unruptured saccular intracranial aneurysms treated with nitinol-based flow diverter stents between 2020 and 2025. Patients with ruptured aneurysms, non-nitinol devices, or incomplete 6-month follow-up data were excluded. Technical success, device-related complications, and clinical outcomes were assessed using standardized imaging follow-up at 1 month (CT angiography) and 6 months (digital subtraction angiography). Results: Technical success was achieved in 109/109 cases (100%). The internal carotid artery cavernous segment was the most common aneurysm location. Intra- and peri-procedural device-related complications occurred in 12/109 (11%) patients, all of which were successfully managed without permanent neurological deficit. During the 6-month follow-up, post-procedural device-related complications occurred in 5/109 patients (4.6%), all due to delayed stent thrombosis requiring mechanical thrombectomy. One patient died due to persistent stent occlusion, and one patient developed unilateral lower-extremity plegia. Three patients experienced transient, non-device-related hypoesthesia that resolved during follow-up. At 6 months, most patients had favorable functional outcomes, with modified Rankin Scale scores of 0–1. Complete aneurysm occlusion was achieved in 83 of 108 patients (76.9%) at the 6-month angiographic follow-up. Conclusions: Flow diverter stents demonstrated high technical success and favorable clinical outcomes. Fishmouth deformity emerged as a potentially important technical factor associated with thrombotic complications and warrants careful recognition during deployment and follow-up. Full article

Background: Flow diverters (FDs) are widely used to treat intracranial aneurysms. Although effective, FD-related thrombosis or progressive stenosis may lead to acute or delayed cerebral hypoperfusion with significant neurological morbidity. Management options are limited when medical or endovascular rescue strategies fail. This study aims to evaluate the role of extracranial–intracranial bypass (EC-IC bypass) as a rescue strategy across the spectrum of FD-related cerebral hypoperfusion. Methods: We retrospectively reviewed all patients who underwent EC-IC bypass for FD-related cerebral hypoperfusion over a 10-year period in our institution. Both acute and chronic presentations were included. Clinical status was assessed using the modified Rankin Scale (mRS). Imaging evaluation included digital subtraction angiography (DSA), computed tomography angiography (CTA), magnetic resonance angiography (MRA) and quantitative magnetic resonance imaging for bypass flow assessment. Surgical technique, antiplatelet therapy, timing of intervention and clinical outcomes were analysed. Results: Five patients with FD-related cerebral hypoperfusion who underwent superficial temporal artery–middle cerebral artery bypass (STA-MCA bypass) were identified. Two distinct patterns emerged. Three patients developed early hypoperfusion within the first month of FD placement, presenting with acute neurological deficits and treated by emergent or urgent bypass under dual antiplatelet therapy. Two patients developed late hypoperfusion years after the procedure, presenting with progressive haemodynamic symptoms and treated by elective flow-augmentation bypass under aspirin monotherapy. At discharge, only one patient had an mRS ≥ 3. At one-year follow-up, a favourable outcome (mRS ≤ 2) was observed in all patients with available data. Follow-up data were missing for one patient. Conclusions: EC-IC bypass represents a feasible rescue strategy for FD-related cerebral hypoperfusion when medical or endovascular treatments fail. In our experience, though limited, STA-MCA bypass can provide sufficient cerebral reperfusion, even in urgent settings and under dual antiplatelet therapy, leading to favourable neurological outcomes. Full article

Objective: Giant thrombosed intracranial aneurysms (GTIAs) are aneurysmal dilatations containing partial or complete intraluminal thrombus. Representing approximately 2–5% of intracranial aneurysms, GTIAs present diagnostic and therapeutic challenges. Optimal management remains controversial and may involve microsurgical, endovascular, or hybrid strategies. Methods: A systematic review was performed in accordance with PRISMA guidelines using PubMed and Embase to identify relevant studies published between January 2000 and August 2025. Eligible studies reported clinical, anatomical, or treatment-related data for patients with GTIAs. Extracted variables included patient demographics, aneurysm characteristics, treatment modality, and outcomes. Data were standardized and analyzed using Python. Complication and recurrence rates were pooled in subsets of studies reporting explicit event counts; comparisons between treatment modalities were assessed using chi-square analysis. Results: In total, 101 studies including 536 patients met our criteria. Mean patient age was 50.2 years. Most aneurysms arose from the anterior circulation (88.2%) involving the internal carotid artery (46.6%) and middle cerebral artery (39.9%). The unweighted mean aneurysm diameter was 39.0 mm, with a patient-weighted mean of 24.3 mm. Hybrid treatment strategies were most frequently reported (62.7%), followed by endovascular (23.3%) and microsurgical (14.0%) approaches. Among studies reporting explicit counts, the pooled complication rate was 17.0% and the recurrence rate was 21.0%. Complication rates did not differ significantly between treatment modalities (p = 0.48), whereas recurrence differed significantly (p = 0.00013). Conclusions: Management of GTIAs remains heterogeneous, with increasing reliance on multimodal and hybrid treatment strategies. However, inconsistent outcome reporting and the predominance of retrospective studies limit definitive comparisons between treatment modalities. Full article

Background & Objectives: Endovascular embolization has matured into a sophisticated, precision-guided discipline that is central to the management of complex neurovascular pathologies. This review synthesizes contemporary treatment strategies, evaluating the advanced material characteristics of conventional inert liquid polymers, specifically non-adhesive ethylene vinyl alcohol (EVOH) copolymers and adhesive cyanoacrylates, alongside their targeted clinical applications in brain arteriovenous malformations (bAVMs), dural arteriovenous fistulas (dAVFs), hypervascular intracranial tumors, and chronic subdural hematomas (CSDHs). Furthermore, it examines the critical material and hemodynamic constraints that limit these agents in cerebral aneurysm repair. Methods: A comprehensive literature synthesis through 3 July 2026 was integrated with peer-reviewed clinical illustrations to evaluate both procedural mechanics and the necessity of post-procedural physiological management. Review Findings: Embolization serves a critical dual role: as a definitive curative therapy and as an essential preoperative or radiosurgical adjunct. As demonstrated by recent clinical validations, technical angiographic success must be closely coupled with vigilant neurocritical oversight to manage profound, localized hemodynamic shifts. While these conventional methods represent established clinical practice, the field is evolving away from inert mechanical occlusion toward a highly integrated approach. The convergence of stimuli-responsive “smart” hydrogels and endovascular robotics is being evaluated for potential roles in transforming these interventions into dynamic, bioactive platforms capable of modulating disease-specific mechanisms, such as Rat Sarcoma-Mitogen-Activated Protein Kinase (RAS-MAPK) and Bone Morphogenetic Protein (BMP) signaling in bAVMs or the Von Hippel-Lindau/Vascular Endothelial Growth Factor (VHL/VEGF) axis in hypervascular tumors. This review further analyzes landmark data, including the Squid Trial For the Embolization of the Middle Meningeal Artery for Treatment of Chronic Subdural Hematoma (STEM) trial for CSDH, providing a synthesis for translating these advanced material sciences into standardized, multidisciplinary neurointerventional care. Full article

Traumatic intracranial aneurysms (TICAs) are rare lesions accounting for <1% of intracranial aneurysms and are associated with high morbidity and mortality. They frequently arise after blunt trauma and may develop days to months following the initial injury, often evading early vascular imaging. Pseudoaneurysms predominate and carry a high risk of rupture. We report the case of a patient who sustained a severe head injury with a comminuted open depressed temporoparietal skull fracture, epidural hematoma, subarachnoid hemorrhage, and mandibular fracture after a road traffic accident. Initial vascular imaging revealed no aneurysm. At six-month follow-up, CT angiography demonstrated a 7 × 5 mm pseudoaneurysm arising from the rolandic branch of the right M3 middle cerebral artery, within an area of post-traumatic encephalomalacia. The aneurysm was confirmed by MRI/MRA and treated successfully with microsurgical clipping. This case underscores the importance of delayed vascular imaging in trauma patients with skull fractures or parenchymal injury, even when early angiography is normal. TICAs may develop over several months, and timely identification permits definitive management before rupture. Full article

Background and Objectives: Three-dimensional (3D) coils offer stable initial framing in intracranial aneurysm embolization, but their utility in pulmonary and visceral vascular lesions has not been well established. The objective of this study was to assess the feasibility, safety, and effectiveness of 3D coils used as the primary framing device in pulmonary and visceral embolization. Materials and Methods: This retrospective study included 13 patients with 14 lesions, comprising seven pulmonary arteriovenous malformations (PAVMs), six splenic artery aneurysms (SAAs), and one hepatic artery pseudoaneurysm (HAP), treated between 2024 and 2025. In all lesions, a 0.018-inch 3D coil was deployed as the initial framing coil, followed by further packing with additional 3D or non-3D coils. Technical success, angiographic success, and clinical outcomes were evaluated. Results: Technical success was achieved in all lesions (14/14, 100%; 95% CI, 78.5–100). Angiographic success was achieved in 13 of 14 lesions (92.9%; 95% CI, 68.5–98.7), and clinical success was achieved in 12 of 13 lesions (92.3%; 95% CI, 66.7–98.6). Post-embolization syndrome (PES) developed in five patients with SAAs and in one patient with HAP; all complications were minor and resolved with conservative management. No coil migration or major complications occurred. Conclusions: When used as the initial framing device, 3D coils were technically feasible and achieved acceptable short-term angiographic and clinical outcomes in this small, heterogeneous series; these preliminary findings require confirmation in comparative studies. Full article

Extracranial–intracranial (EC-IC) bypass surgery remains an essential tool in the management of complex cerebrovascular disease, including chronic-ischemic hypoperfused territory as well as intracranial aneurysms requiring parent vessel sacrifice. Reliable postoperative surveillance of graft patency and hemodynamic function is central to long-term success. Sonographic imaging has evolved over four decades from indirect extracranial Doppler waveform analysis through intraoperative microvascular Doppler, quantitative duplex ultrasonography, and transcranial Doppler assessment of intracranial hemodynamics to the contemporary development of trans-sonolucent cranioplasty ultrasonography (TCUS). TCUS, enabled by the replacement of the autologous bone flap with an acoustically transparent polymethyl methacrylate (PMMA) cranioplasty, permits direct, real-time visualization of the anastomosis and surrounding intracranial vasculature. This can be performed at the bedside and in the outpatient setting, without radiation or contrast. Current evidence, drawn largely from small series and early multicenter experience, positions TCUS as a reliable and potentially cost-effective complement to digital subtraction angiography for serial bypass surveillance, though prospective validation remains needed. This review traces the full arc of sonographic bypass monitoring and addresses current evidence, technical considerations, established quantitative parameters, and directions for future investigation. Full article

Background/Objectives: Oculomotor nerve palsy (OMNP) is a clinically significant condition that may represent the earliest manifestation of life-threatening intracranial pathology, particularly aneurysmal compression or neoplasia. Despite its neurosurgical relevance, comprehensive meta-analytic evidence synthesizing OMNP etiologies, clinical presentation, and contemporary diagnostic pathways remains limited. Methods: Following PRISMA 2020 guidelines, MEDLINE, Scopus, and Web of Science were systematically searched for studies reporting quantitative data on OMNP. Pooled prevalence estimates were calculated using random-effects models for causes and symptoms, while a structured narrative synthesis was performed for diagnostic modalities because outcome reporting was heterogeneous and unsuitable for meta-analysis. Risk of bias was assessed using the Joanna Briggs Institute (JBI) risk of bias tool. Results: Twenty-four studies involving 5541 patients were included. Using a multivariate multilevel model to account for within-study dependence, the most common etiological category was vascular disorders (35.62%), followed by idiopathic (16.47%) and neoplastic (12.10%). Head trauma and aneurysms accounted for 11.26% and 10.08% of cases, respectively. Diplopia (60.63%) and ptosis (54.12%) remained the predominant clinical symptoms, while pupil involvement was identified in 40.62% of the pooled population. Diagnostic paradigms have shifted decisively toward non-invasive neuroimaging, with magnetic resonance imaging reported in 66% of included studies and magnetic resonance or computed tomographic angiography increasingly employed to identify surgically relevant vascular lesions. Conclusions: Although vascular disorders represented the most common etiological category, the notable prevalence of aneurysmal and neoplastic causes underscores the importance of prompt high-resolution neuroimaging and early neurosurgical assessment. Early recognition and etiological stratification remain essential to optimize management and prevent irreversible neurological morbidity. Full article

Intracranial aneurysms are common vascular lesions with a highly variable natural history. While most unruptured intracranial aneurysms remain stable throughout life, a biologically aggressive subset progresses to growth and rupture, resulting in aneurysmal subarachnoid hemorrhage with substantial morbidity and mortality. Contemporary evidence demonstrates that aneurysm behavior is dynamic rather than static and reflects the interaction of hemodynamic forces, inflammatory vascular remodeling, genetic susceptibility, and environmental risk factors. Rupture risk is not constant over time and may be highest early after aneurysm formation, followed by a period of relative quiescence in selected lesions. Traditional population-based risk estimates have therefore evolved toward individualized risk stratification incorporating aneurysm size, location, morphology, growth, patient-specific factors, and emerging imaging and computational biomarkers. This chapter reviews the epidemiology, pathobiology, growth patterns, and rupture risk of intracranial aneurysms, integrating foundational observational studies with recent advances in genetics, vessel wall imaging, and predictive modeling. Understanding the natural history of brain aneurysms is essential for balancing the risks of observation against intervention and for guiding future innovations in aneurysm management. Full article

Background: Contemporary aneurysm surgery increasingly requires the management of complex lesions with limited physiological reserve. A growing “physiology-first” paradigm emphasizes that optimizing cerebrovascular dynamics during aneurysm treatment is essential for favorable neurological outcomes. Methods: This narrative review synthesizes current evidence and expert perspectives on cerebrovascular physiology relevant to aneurysm surgery, including cerebral perfusion, autoregulation, ischemia tolerance, neuroprotection, and intraoperative monitoring. Results: Key themes include individualized blood pressure management, recognition of impaired autoregulation—particularly after subarachnoid hemorrhage—safe application of temporary arterial occlusion, and the use of multimodal neuromonitoring to detect ischemia in real time. The strengths and limitations of neuroprotective adjuncts are critically discussed in the context of available clinical evidence. Conclusions: Integrating cerebrovascular physiology into aneurysm surgery supports informed intraoperative decision-making, minimizes ischemic injury, and enhances patient outcomes. A physiology-first approach complements technical expertise and represents a cornerstone of modern neurovascular practice. Full article