Knowledge domain and emerging trends in the rupture risk of intracranial aneurysms research from 2004 to 2023

BACKGROUND Intracranial aneurysms(IAs)pose significant health risks,attributable to their potential for sudden rupture,which can result in severe outcomes such as stroke and death.Despite extensive research,the variability of aneurysm behavior,with some remaining stable for years while others rupture unexpectedly,remains poorly understood.AIM To employ bibliometric analysis to map the research landscape concerning risk factors associated with IAs rupture.METHODS A systematic literature review of publications from 2004 to 2023 was conducted,analyzing 3804 documents from the Web of Science Core Collection database,with a focus on full-text articles and reviews in English.The analysis encompassed citation and co-citation networks,keyword bursts,and temporal trends to delineate the evolution of research themes and collaboration patterns.Advanced software tools,CiteSpace and VOSviewer,were utilized for comprehensive data visualization and trend analysis.RESULTS Analysis uncovered a total of 3804 publications on IA rupture risk factors between 2006 and 2023.Research interest surged after 2013,peaking in 2023.The United States led with 28.97%of publications,garnering 37706 citations.Notable United States-China collaborations were observed.Capital Medical University produced 184 publications,while Utrecht University boasted a citation average of 69.62 per publication.“World Neurosurgery”published the most papers,contrasting with“Stroke”,the most cited journal.The PHASES score from“Lancet Neurology”emerged as a vital rupture risk prediction tool.Early research favored endovascular therapy,transitioning to magnetic resonance imaging and flow diverters.CONCLUSION This study assesses global IA research trends and highlights crucial gaps,guiding future investigations to improve preventive and therapeutic approaches.

Morphological characteristics associated with rupture risk of multiple intracranial aneurysms

Objective: To identify the morphological parameters that are related to intracranial aneurysms(IAs) rupture using a case-control model.Methods: A total of 107 patients with multiple IAs and aneurysmal subarachnoid hemorrhage between August 2011 and February 2017 were enrolled in this study.Characteristics of IAs location, shape, neck width, perpendicular height, depth, maximum size, flow angle, parent vessel diameter(PVD), aspect ratio(AR) and size ratio(SR) were evaluated using CT angiography.Multiple logistic regression analysis was used to identify the independent risk factors associated with IAs rupture.Receiver operating characteristic curve analysis was performed on the final model, and the optimal thresholds were obtained.Results: IAs located in the internal carotid artery(ICA) was associated with a negative risk of rupture, whereas AR, SR1(height/PVD) and SR2(depth/PVD) were associated with increased risk of rupture.When SR was calculated differently, the odds ratio values of these factors were also different.The receiver operating characteristic curve showed that AR, SR1 and SR2 had cut-off values of 1.01, 1.48 and 1.40, respectively.SR3(maximum size/PVD) was not associated with IAs rupture.Conclusions: IAs located in the ICA are associated with a negative risk of rupture, while high AR(>1.01), SR1(>1.48) or SR2(>1.40) are risk factors for multiple IAs rupture.

Interventional therapy for intracranial aneurysms under neuroelectrophysiological monitoring

Objective To study the application of neuroelectrophysiological monitoring for interventional therapy of intracranial aneurysms. Methods 22 patients with intracranial aneurysm underwent neuroelectrophysiological monitoring during interventional therapy. Somatosensory evoked potential( SSEP) ,brainstem

Wall shear stress in intracranial aneurysms and adjacent arteries

Hemodynamic parameters play an important role in aneurysm formation and growth. However, it is difficult to directly observe a rapidly growing de novo aneurysm in a patient. To investigate possible associations between hemodynamic parameters and the formation and growth of intracranial aneurysms, the present study constructed a computational model of a case with an internal carotid artery aneurysm and an anterior communicating artery aneurysm, based on the CT angiography findings of a patient. To simulate the formation of the anterior communicating artery aneurysm and the growth of the internal carotid artery aneurysm, we then constructed a model that virtually removed the anterior communicating artery aneurysm, and a further two models that also progressively decreased the size of the internal carotid artery aneurysm. Computational simulations of the fluid dynamics of the four models were performed under pulsatile flow conditions, and wall shear stress was compared among the different models. In the three aneurysm growth models, increasing size of the aneurysm was associated with an increased area of low wall shear stress, a significant decrease in wall shear stress at the dome of the aneurysm, and a significant change in the wall shear stress of the parent artery. The wall shear stress of the anterior communicating artery remained low, and was significantly lower than the wall shear stress at the bifurcation of the internal carotid artery or the bifurcation of the middle cerebral artery. After formation of the anterior communicating artery aneurysm, the wall shear stress at the dome of the internal carotid artery aneurysm increased significantly, and the wall shear stress in the upstream arteries also changed significantly. These findings indicate that low wall shear stress may be associated with the initiation and growth of aneurysms, and that aneurysm formation and growth may influence hemodynamic parameters in the local and adjacent arteries.

Efficacy of pipeline endovascular device and Willis stent graft in the treatment of traumatic pseudo intracranial aneurysms

Objective:To investigate the advantages and effects of pipeline embolization device(PED)or Willis stent,in treating traumatic pseudoaneurysms.Traumatic pseudo intracranial aneurysms(TPIA)can be caused by either direct trauma or iatrogenic injuries,usually caused by direct arterial wall injury or shear due to acceleration.We describe a series of patients with TPIA who received a PED or Willis stent.Materials and methods:Retrospective analysis was performed on nine patients with TPIA admitted to the southern hospital of Southern Medical University from December 2017 to June 2019,of whom four were treated with PED and five were implanted with six Willis covered stents.The occlusive rate and complication in the two kinds of stents were compared by postoperative follow-up and modified rankin score(MRS).Results:After the implantation of PED,four patients showed an immediate stagnation of blood flow or a decreased filling in aneurysms,three out of four patients exhibited complete occlusion,and the remaining patient had nearly complete occlusion.Four out of five cases of Willis stent implantation were associated with immediate complete occlusion of aneurysms,and the modified rankin score of these patients ranged from 0 to 1.One patient died of unassociated complications.Conclusion:For different types of TPIA in the internal carotid artery(ICA),PED and Willis stents provide significant advantages in treatment,with fewer postoperative complications and prognosis well.

Applications of multislice CT angiography in the surgical clipping and endovascular coiling of intracranial aneurysms

Prompt diagnosis and therapy of aneurysms are critical for patients with nontraumatic subarachnoid hemorrhage （SAH）.The aim of our study was to assess the clinical usefulness of multislice computed tomography angiography （CTA） in the surgical and endovascular treatment of intracranial aneurysms.A total of 195 cases with 206 intracranial aneurysms underwent CTA.Fifty （24%） aneurysms underwent surgical clipping while 156 （76%） aneurysms underwent endovascular coiling.In the five missed aneurysms at digital substraction angiography and the nine aneurysms with mass intracerebral hematomas,surgical treatment was successfully performed based on 16-slice CTA alone,and the other 36 aneurysms were clipped on the main basis of the CTA.The intraoperative findings correlated well with the CTA findings and all aneurysms were clipped successfully.Sixteen-slice CTA image information has been shown to determine the choice of aneurysm therapy and assist the surgical and endovascular treatment of intracranial aneurysms.

Safety and efficacy of complete versus near-complete coiling in treatment of intracranial aneurysms

Objective:This study aimed to evaluate the clinical and angiographic outcomes of aneurysms that were completely or near-completely embolized and ascertain whether complete embolization is important in the stent-assisted coiling(SAC)of intracranial aneurysms.Methods:This retrospective study enrolled 390 patients(417 aneurysms).Among them,complete(100%)or nearcomplete(>90%)angiographic obliteration of the aneurysms on immediate angiography was accomplished.Baseline characteristics,complications,angiography follow-up results,and clinical outcomes were analyzed.Results:Cumulative adverse events occurred in 30 patients(7.7%),including thromboembolic complications in 17(4.4%),intraoperative rupture in 10(2.6%),and others in 3(0.8%).Statistical analyses revealed an increased intraprocedural rupture rate in the initial completely occluded aneurysms(5.6%compared with 1.0%).The incidence of cumulative adverse events was higher in patients with completely occluded aneurysms(11.1%)than in those with near-completely occluded aneurysms(5.5%).Angiography follow-up was available for 173 aneurysms.Aneurysm occlusion status at follow-up was correlated with stent placement(p?0.000,odds ratio?5.847),size(p?0.000,odds ratio?6.446 for tiny aneurysms;and p?0.001,odds ratio?5.616 for small aneurysms),and initial aneurysm occlusion status(p?0.001,odds ratio?3.436).Complete occlusion at followup was seen in 82.6%of the initial complete occlusion group versus 63.0%of the initial near-complete occlusion group.The incidence of complete occlusion at follow-up was higher in the initial completely occluded aneurysms with SAC(100%)than in the initial completely occluded aneurysms with non-SAC(65.2%).Conclusions:Initial complete treatment may lead to higher complication rates and good clinical outcomes at follow-up.Stent placement may enhance progressive aneurysm occlusion.Initial complete occlusion with SAC can provide durable closure at follow-up.

Research progress in the causes of intracranial aneurysms

Subaracoid hemorrhage caused by intracranial aneurysms is characterized by high morbidity and mortality.There is no definite conclusion regarding the mechanism of formation,development,and rupture of intracranial aneurysms.It is generally believed to be related to congenital hereditary connective tissue diseases and acquired hemodynamic factors,vascular inflammation,and oral pathogens.In addition,gender,age,hypertension,and psychological status are also important factors.Relevant studies show a significantly lower quality of life in patients with intracranial aneurysms,and psychological factors should be studied in more depth.Neurological complications are considered an important factor in the decrease in quality of life.In conclusion,the formation,development,and rupture of intracranial aneurysms should result from a combination of congenital and acquired factors.

Microsurgical Management of Intracranial Aneurysms in Côte d’Ivoire: A Series of 128 Cases

Introduction: The management of intracranial aneurysms in sub-Saharan Africa is essentially surgical. In this retrospective study, the authors report their experience in surgical management of intracranial aneurysm in Côte d’Ivoire. Methods: We carried out a retrospective study on patients operated for a ruptured or unruptured intracranial aneurysm between January 1st, 2012 and December 31st, 2018. Data on epidemiological characteristics of patients and aneurysms, treatments and patient outcomes were analyzed. Results: One hundred twenty eight aneurysms were operated. Sixty-six percent of the patients were female. According to the World Federation of Neurosurgical Societies (WFNS) scale, 58, 5% of patients were in grade I. Fisher scale showed 29% of Fisher 2 and 49% of Fisher 4. The aneurysms were mainly located on the internal carotid artery in 38% and anterior complex in 36%. The average size of aneurysms was 6.5 mm. In 81.4% the size of the aneurysms was less than 10 mm. Most aneurysms (90%) were treated at late stage. According to the modified Rankin Scale, 92 patients (83%) had good outcome, 7 patients (6%) had poor outcome, and the mortality rate was 11%. Conclusions: This study shows encouraging results if we refer to the overall postoperative results. However, there is a sub-diagnosis and low treatment rate of ruptured intracranial aneurysms. The improvement of intracranial aneurysms management requires improving the standard of health in the country.

Risk factors and outcomes of postoperative stroke in surgical treatment for giant intracranial aneurysms

Background:Giant intracranial aneurysms(GIAs)are challenges for surgical treatment.Risk factors of postoperative stroke remain unclear.This study aims to investigate the predictors of postoperative stroke in GIAs and the impact of stroke on outcomes.Methods:We performed a retrospective medical record review of patients with GIAs who received microsurgery at our institution between 2011 and 2018.Multivariate logistic regression analyses were carried out to identify risk factors for postoperative stroke.The clinical and angiographic outcomes were compared between patients with and without stroke.Results:A total of 97 patients were included in this study.Surgical modalities included direct aneurysm neck clipping in 85 patients(87.7%),trapping with the bypass in 8(8.2%),proximal artery ligation in 1(1%),and bypass alone in 3(3.1%).Postoperative stroke was found in 26 patients(26.8%).Independent factors that affect postoperative stroke were recurrent aneurysm(OR,10.982;95%CI,1.976-61.045;P=0.006)and size≥3.5 cm(OR,3.420;95%CI,1.133-10.327;P=0.029).Combined perioperative mortality and morbidity was 26.8%.Follow-up was achieved from 89 patients(91.8%),with a mean follow-up period of 39 months(range 19 to 94 months).Good outcomes were observed in 75 patients(84.3%)and poor outcomes were observed in 14 patients(15.7%).Conclusions:Postoperative stroke was significantly associated with clinical outcome.Favorable outcomes can be achieved in most patients with GIAs after appropriate microsurgical modality.Recurrent aneurysm and size≥3.5 cm are risk factors of postoperative stroke.

Effects of Enterprise 2 stent-assisted coil embolization for wide-necked intracranial aneurysms

Background:This study analyzed the safety and efficacy of Enterprise 2 stent-assisted coil embolization for wide-necked intracranial aneurysms by examining stent-vessel apposition,operative complications,embolization outcomes,and clinical outcomes.Methods:We retrospectively reviewed the medical records of patients with wide-necked intracranial aneurysms who underwent Enterprise 2 stent-assisted coiling in our hospital from November 2018 to October 2019.Intraoperative VasoCT was performed immediately after stent release in a continuous cohort of patients to observe stent-vessel apposition.Patient demographic,clinical,and imaging data were recorded and analyzed.Results:A total of 106 wide-necked aneurysms in 106 patients were treated.Stent release was successful in all patients.Twenty-one patients were enrolled consecutively for VasoCT scanning,and incomplete stent apposition was observed in 5(23.8%).Perioperative complications occurred in 10 patients(9.4%):cerebral infarction in 6,intraoperative coil prolapse in 1,puncture site pseudoaneurysm in 1,deep vein thrombosis at multiple sites in 1,and transient brainstem mass effect in 1.Among the 95 aneurysms with angiographic follow-up,embolization was satisfactory(Raymond-Roy classifications I and II)in 89(93.7%).Hyperlipidemia was an independent risk factor for incomplete aneurysm occlusion.At the last clinical follow-up,seven patients had a poor clinical outcome(modified Rankin Scale score≥3).Independent risk factors for poor outcomes were preoperative subarachnoid hemorrhage at presentation and cerebral infarction.Conclusion:Enterprise 2 stent-assisted coiling for treatment of wide-necked intracranial aneurysms showed good safety and efficacy;however,incomplete stent apposition can still occur in vessels with a large curvature.Preoperative subarachnoid hemorrhage at presentation and cerebral infarction are the main reasons for poor clinical outcomes after stent-assisted coil embolization.

A two-step surface-based 3D deep learning pipeline for segmentation of intracranial aneurysms

The exact shape of intracranial aneurysms is critical in medical diagnosis and surgical planning.While voxel-based deep learning frameworks have been proposed for this segmentation task,their performance remains limited.In this study,we offer a two-step surface-based deep learning pipeline that achieves significantly better results.Our proposed model takes a surface model of an entire set of principal brain arteries containing aneurysms as input and returns aneurysm surfaces as output.A user first generates a surface model by manually specifying multiple thresholds for time-of-flight magnetic resonance angiography images.The system then samples small surface fragments from the entire set of brain arteries and classifies the surface fragments according to whether aneurysms are present using a point-based deep learning network(PointNet++).Finally,the system applies surface segmentation(SO-Net)to surface fragments containing aneurysms.We conduct a direct comparison of the segmentation performance of our proposed surface-based framework and an existing voxel-based method by counting voxels:our framework achieves a much higher Dice similarity(72%)than the prior approach(46%).

An unusual etiology of subarachnoid hemorrhage,basilar artery perforator aneurysms,in Macao:Three case reports and review of literature

BACKGROUND Subarachnoid hemorrhage is a severe neurological condition that requires prompt and appropriate treatment to prevent complications.Aneurysms are the most common cause of spontaneous subarachnoid hemorrhage.Conversely,basilar artery perforator aneurysms(BAPAs)are a rare etiology.There is no consensus on the optimal management of ruptured BAPAs in the acute setting.CASE SUMMARY We present a case series of 3 patients with ruptured BAPAs who were treated at our institution.Two patients had a modified Fisher grade of I,and one had a grade of IV on initial presentation.The aneurysms were detected by computed tomography angiography in two cases and conventional angiography in one case.The 3 patients underwent endovascular treatment with Guglielmi detachable coils.Post-treatment,the patients had good clinical outcomes,and follow-up brain computed tomography scans showed reduced subarachnoid hemorrhage without any new hemorrhage.However,one patient experienced a cerebral infarction 2 months later and eventually succumbed to the condition.The other 2 patients showed progressive recovery,and no aneurysm recurrence was observed at the 2-year follow-up.CONCLUSION Endovascular treatment may be a preferable approach for managing ruptured BAPAs compared with surgical intervention or conservative management.Early detection and prompt treatment is important to achieve favorable patient outcomes.

Endovascular treatment of ruptured lobulated anterior communicating artery aneurysms:A retrospective study of 24 patients

BACKGROUND Lobulated intracranial aneurysm is a special type of aneurysm with at least one additional cyst in the neck or body of the aneurysm.Lobulated intracranial aneurysm is a complex aneurysm with complex morphology and structure and weak tumor wall,which is an independent risk factor for rupture and hemorrhage.Lobular aneurysms located in the anterior communicating artery complex account for 36.9%of all intracranial lobular aneurysms.Due to its special anatomical structure,both craniotomy and endovascular treatment are more difficult.Compared with single-capsule aneurysms,craniotomy for lobular intracranial aneurysms has a higher risk and complication rate.AIM To investigate the efficacy and safety of endovascular treatment for ruptured lobulated anterior communicating artery aneurysm(ACoAA).METHODS Patients with ruptured lobulated ACoAA received endovascular treatment in Sanming First Hospital Affiliated to Fujian Medical University from June 2020 to June 2022 were retrospectively included.Their demographic,clinical and imaging characteristics,endovascular treatment methods and follow-up results were collected.RESULTS A total of 24 patients with ruptured lobulated ACoAA were included,including 9 males(37.5%)and 15 females(62.5%).Their age was 56.2±8.9 years old(range 39-74).The time from rupture to endovascular treatment was 10.9±12.5 h.The maximum diameter of the aneurysms was 5.1±1.0 mm and neck width were 3.0±0.7 mm.Nineteen patients(79.2%)were double-lobed and 5(20.8%)were multilobed.Fisher's grade:Grade 2 in 16 cases(66.7%),grade 3 in 6 cases(25%),and grade 4 in 2 cases(8.3%).Hunt-Hess grade:Grade 0-2 in 5 cases(20.8%),grade 3-5 in 19 cases(79.2%).Glasgow Coma Scale score:9-12 in 14 cases(58.3%),13-15 in 10 cases(41.7%).Immediately postprocedural Raymond-Roy grade:grade 1 in 23 cases(95.8%),grade 2 in 1 case(4.2%).Raymond-Roy grade in imaging follow-up for 2 wk to 3 months:grade 1 in 23 cases(95.8%),grade 2 in 1 case(4.2%).Followup for 2 to 12 months showed that 21 patients(87.5%)had good functional outcomes(modified Rankin Scale score≤2),and there were no deaths.CONCLUSION Endovascular treatment is a safe and effective treatment for ruptured lobulated AcoAA.

Giant cavernous aneurysms occluded by aneurysmal thrombosis,calcification,parent artery occlusion:A case report and review of literature

BACKGROUND Patients with giant intracranial aneurysms(GIAs)are at a high risk of rupture,morbidity,and mortality even after surgical or endovascular treatment.We described a case of a spontaneously occluded GIA secondary to gradual growth of the GIA,continuously progressed aneurysmal thrombosis,complete aneurysmal calcification and complete occlusion of the parent artery-the right internal carotid artery(RICA).CASE SUMMARY A 72-year-old female patient complained of sudden pain in her right eye upon admission to our hospital.She had been diagnosed with a GIA[30 mm(axial)×38 mm(coronal)×28 mm(sagittal)]containing an aneurysmal thrombus located in the cavernous sinus segment of RICA diagnosed by magnetic resonance imaging(MRI),enhanced MRI,and magnetic resonance angiography more than 14 years ago.Later,with slow growth of the cavernous carotid GIA,aneurysmal thrombosis progressed continuously,spontaneous occlusion of the RICA,complete aneurysmal calcification,and occlusion of the GIA occurred gradually.She had no history of subarachnoid hemorrhage but missed the chance for endovascular therapy at an early stage.As a result,she was left with severe permanent sequelae from the injuries to the right cranial nerves Ⅱ,Ⅲ,Ⅳ,V1/V2,and Ⅴ.CONCLUSION The risk of rupture of the cavernous carotid GIAs was relatively low and possibly further be reduced by the stasis flow and spontaneous occlusion of the parent artery internal carotid artery(ICA)induced by the mass effect of the cavernous carotid GIAs and the extremely rare aneurysmal calcification.However,nowadays,it is advisable to recommend early endovascular treatment for the cavernous carotid GIAs to prevent injuries to the surrounding intracranial nerves and occlusion of the ICA,mainly caused by the mass effect of the cavernous carotid GIAs.

Three-dimensional CT angiography and surgical correlation in the evaluation of intracranial aneurysms

OBJECTIVE: To evaluate the diagnostic accuracy of three-dimensional CT angiography in the surgical treatment of intracranial aneurysms. METHODS: Twenty-four patients suspected of intracranial aneurysms underwent routine catheter four-vessel angiography, three dimensional CT angiography (3D-CTA), magnetic resonance angiography (MRA) or conventional digital subtraction angiography (DSA). RESULTS: A total of 28 aneurysms were detected by CT angiography in this study. Twenty-one patients each had a single aneurysm, two patients each had two aneurysms, and one had three aneurysms. The shapes of aneurysms revealed by 3D-CTA were round in 20 lesions, elliptical in 5, and 1 obulated in 3. Of the 24 lesions which were completely disclosed during surgery, the shapes correlated well with the 3D-CT angiograms. The mean diameter of the aneurysmal neck was 5.9 mm in 3D-CTA images, with the smallest being 1.6 mm and the largest 13.7 mm. The size was very close to the actual size measured at surgery (P

Gene expression profiles in intracranial aneurysms

In this study, we extracted total RNA from 15 intracranial aneurysms and 17 superficial temporal artery samples, then performed genome-wide expression profiling using the Affymetrix U133 Plus 2.0 GeneChip. Genes that were differentially expressed between intracranial aneurysms and arterial samples were identified using significance analysis for microarrays, and the expression patterns of three randomly-selected genes were verified by real-time polymerase chain reaction analysis. We identified 3 736 differentially-expressed genes out of the 47 000 assayed transcripts. A total of 179 genes showed a 〉10-fold change in expression between the aneurysms and the arterial samples. Genes involved in the proliferation, migration, and apoptosis of vascular muscle cells, atherosclerosis, extracellular matrix disruption, and inflammatory reactions were associated with the formation of intracranial aneurysms. There were no significant differences in gene expression profile between unruptured and ruptured aneurysms.

Endovascular coiling versus microsurgical clipping for ruptured intracranial aneurysms:a meta-analysis and systematic review

Background:The purpose of this analysis is to evaluate the current evidence with regard to the effectiveness and safety between coiling and clipping in patients with ruptured intracranial aneurysms(RIAs).Methods:We performed a meta-analysis that compared clipping with coiling between July 2000 and September 2021.PubMed,EMBASE,and the Cochrane Library were searched for related articles systematically.And the treatment efficacy and postoperative complications were analyzed.Results:We identified three randomized controlled trials and thirty-seven observational studies involving 60,875 patients with ruptured cerebral aneurysms.The summary results showed that coiling was related a better quality of life(mRS0-2;OR=1.327;CI=1.093-1.612;p<0.05),a higher risk of mortality(OR=1.116;CI=1.054-1.180;p<0.05),higher rate of rebleeding(RR=1.410;CI=1.092-1.822;p<0.05),lower incidence of vasospasm(OR=0.787;CI=0.649-0.954;p<0.05),higher risk of hydrocephalous(RR=1.143;CI=1.043-1.252;p<0.05),lower risk of cerebral infarction(RR=0.669;CI=0.596-0.751;p<0.05),lower risk of neuro deficits(RR=0.720;CI=0.582-0.892;p<0.05),and a lower rate of complete occlusion(OR=0.495;CI=0.280-0.876;p<0.05).Conclusion:Coiling was significantly associated with a better life quality(mRS0-2),a lower incidence of postoperative complications,and a higher rate of mortality,rebleeding,hydrocephalous,and a lower rate of complete occlusion than clipping.

A joint computational-experimental study of intracranial aneurysms:Importance of the aspect ratio

Rupture of a cerebral aneurysm （abnormal swelling of blood vessel in the brain） will cause subarachnoid hemorrhage, and will result in an alarming rate of mortality and morbidity. A joint computational-experimental study is conducted to assess the importance of the aspect ratio in the dynamics of blood flow. The aspect ratio is defined here to be the ratio of the height of the aneurysm to the linear dimension of the neck. Idealized models of such aneurysms located near a bifurcation point were investigated. Numerical simulations for hemodynamic properties like shear stress and flow rate were performed. The computational results were verified experimentally with specially fabricated phantoms, blood mimicking fluid and Doppler ultrasound imaging. Excellent agreements were obtained. Two features are highlighted, providing information in the intensely debated link between rupture risk and geometric factors. On increasing the aspect ratios, firstly, a jet impinging on the distal part of the neck can be observed, and secondly, a region of positive shear stress gradient can be found there. Furthermore, computational analyses for four patient-specific models were conducted to correlate with the results of idealized models and to provide further clinical insight.