Intracranial aneurysms

Prehemorrhage antiplatelet use in aneurysmal subarachnoid hemorrhage and impact on clinical outcome

Background

Literature is inconclusive regarding the association between antiplatelet agents use and outcome after aneurysmal subarachnoid hemorrhage.

Aims

To investigate the association between clinical outcome and prehemorrhage use in aneurysmal subarachnoid hemorrhage patients as well as the impact of thrombocyte transfusion on rebleed and clinical outcome.

Methods

Data were collected from prospective databases of two European tertiary reference centers for aneurysmal subarachnoid hemorrhage patients. Patients were divided into “antiplatelet-user” and “non-user” according to the use of acetylsalicylic acid prior to the hemorrhage. Primary outcome was poor clinical outcome at six months (Glasgow Outcome Scale score 1–3). Secondary outcomes were in-hospital mortality and impact of thrombocyte transfusion.

Results

Of the 1033 patients, 161 (15.6%) were antiplatelet users. The antiplatelet users were older with higher incidence of cardiovascular risk factors. Antiplatelet use was associated with poor outcome and in-hospital mortality. After correction for age, sex, World Federation of Neurosurgical Societies score, infarction and heart disorder, pre-hemorrhage acetylsalicylic acid use was only associated with poor clinical outcome at six months (adjusted OR 1.80, 95% CI 1.08–3.02). Thrombocyte transfusion was not associated with a reduction in rebleed or poor clinical outcome.

Conclusion

In this multicenter study, the prehemorrhage acetylsalicylic acid use in aneurysmal subarachnoid hemorrhage patients was independently associated with poor clinical outcome at six months. Thrombocyte transfusion was not associated with the rebleed rate or poor clinical outcome at six months.

Deep Shape Features for Predicting Future Intracranial Aneurysm Growth

Introduction: Intracranial aneurysms (IAs) are a common vascular pathology and are associated with a risk of rupture, which is often fatal. Aneurysm growth is considered a surrogate of rupture risk; therefore, the study aimed to develop and evaluate prediction models of future artificial intelligence (AI) growth based on baseline aneurysm morphology as a computer-aided treatment decision support.

Materials and methods: Follow-up CT angiography (CTA) and magnetic resonance angiography (MRA) angiograms of 39 patients with 44 IAs were classified by an expert as growing and stable (25/19). From the angiograms vascular surface meshes were extracted and the aneurysm shape was characterized by established morphologic features and novel deep shape features. The features corresponding to the baseline aneurysms were used to predict future aneurysm growth using univariate thresholding, multivariate random forest and multi-layer perceptron (MLP) learning, and deep shape learning based on the PointNet++ model.

Results: The proposed deep shape feature learning method achieved an accuracy of 0.82 (sensitivity = 0.96, specificity = 0.63), while the multivariate learning and univariate thresholding methods were inferior with an accuracy of up to 0.68 and 0.63, respectively.

Conclusion: High-performing classification of future growing IAs renders the proposed deep shape features learning approach as the key enabling tool to manage rupture risk in the “no treatment” paradigm of patient follow-up imaging.

Diagnosis and Treatment of Unruptured Intracranial Aneurysms and Aneurysmal Subarachnoid Hemorrhage

Unruptured intracranial aneurysms (UIAs) are commonly acquired vascular lesions that form an outpouching of the arterial wall due to wall thinning. The prevalence of UIAs in the general population is 3.2%. In contrast, an intracranial aneurysm may be manifested after rupture with classic presentation of a thunderclap headache suggesting aneurysmal subarachnoid hemorrhage (SAH). Previous consensus suggests that although small intracranial aneurysms (<7 mm) are less susceptible to rupture, aneurysms larger than 7 mm should be treated on a case-by-case basis with consideration of additional risk factors of aneurysmal growth and rupture. However, this distinction is outdated. The PHASES score, which comprises data pooled from several prospective studies, provides precise estimates by considering not only the aneurysm size but also other variables, such as the aneurysm location. The International Study of Unruptured Intracranial Aneurysms is the largest observational study on the natural history of UIAs, providing the foundation to the current guidelines for the management of UIAs. Although SAH accounts for only 3% of all stroke subtypes, it is associated with considerable burden of morbidity and mortality. The initial management is focused on stabilizing the patient in the intensive care unit with close hemodynamic and serial neurologic monitoring with endovascular or open surgical aneurysm treatment to prevent rebleeding. Since the results of the International Subarachnoid Aneurysm Trial, treatment of aneurysmal SAH has shifted from surgical clipping to endovascular coiling, which demonstrated higher odds of survival free of disability at 1 year after SAH. Nonetheless, aneurysmal SAH remains a public health hazard and is associated with high rates of disability and death.

Screening for cerebrovascular disorder on the basis of family history in asymptomatic children

Background: Cerebrovascular disorders represent a group of uncommon, heterogeneous, and complex conditions in children. We reviewed the screening practice for the detection of cerebrovascular disorder in asymptomatic children referred to our neurovascular service on the basis of a positive family history and parental and/or treating physician concern.Methods: Retrospective case-note review of referrals to our neurovascular service (July 2008-April 2018). Patients were included if the referral was made for screening, on the basis of a positive family history of cerebrovascular disorder. Symptomatic children, those with previous cranial imaging, or children under the care of a clinical geneticist (i.e. due to the child or their relative having HHT or mutations in KRIT1) were not eligible for inclusion.Results: Forty-one children were reviewed, 22 males (Median age 10.7 years, range 0.6-15.6 years). This represented 22% of the total number of referrals over a 10-year period. Twenty-nine children had an MRI/MRA brain. Twenty-eight children were referred due to a family history of intracranial aneurysm and/or subarachnoid haemorrhage, but only two had two first-degree relatives affected. Ten children were referred due to a family history of arteriovenous malformation. Three children were referred due to a family history of stroke. No cerebrovascular disease was detected during the study period (n = 29).Conclusions: Parental and/or physician concern generated a substantial number of referrals but no pathology was detected after screening. Whilst general screening guidance exists for the detection of intracranial aneurysms, consensus guidelines for the screening of children with a positive family history do not, but are required both to guide clinical practice and to assuage parental and/or physician concerns.

Correlation of periodontal diseases with intracranial aneurysm formation: novel predictive indicators

Background

We investigated whether periodontal diseases, specifically, periodontitis and gingivitis, could be risk factors of the incidence of intracranial aneurysms (IAs).

Methods

We performed a case–control study to compare the differences in the periodontal disease parameters of 281 cases that were divided into the IAs group and non-IAs group. All cases underwent complete radiographic examination for IAs and examination for periodontal health.

Results

Comparing with those in the non-IAs group, the cases in the IAs group were older (53.95 ± 8.56 vs 47.79 ± 12.33, p < 0.001) and had a higher incidence of hypertension (76 vs 34, p = 0.006). Univariate logistic regression analysis revealed that age (> 50 years) and hypertension were predictive risk factors of aneurysm formation (odds ratio [OR] 1.047, 95% confidence interval [95% CI] 1.022–1.073, p < 0.001 and OR 2.047, 95% CI 1.232–3.401, p = 0.006). In addition, univariate and multivariate logistic regression analyses showed that the parameters of periodontal diseases, including gingival index, plaque index, clinical attachment loss, and alveolar bone loss, were significantly associated with the occurrence of IAs (all p < 0.05). For further statistical investigation, the parameters of periodontal diseases were divided into four layers based on the quartered data. Poorer periodontal health condition (especially gingival index > 1.1 and plaque index > 1.5) had the correlation with IAs formation (p = 0.007 and p < 0.001).

Conclusion

Severe gingivitis or periodontitis, combining with hypertension, is significantly associated with the incidence of IAs.

Valproic Acid Reduces Vasospasm through Modulation of Akt Phosphorylation and Attenuates Neuronal Apoptosis in Subarachnoid Hemorrhage Rats

Aneurysmal subarachnoid hemorrhage (SAH) is a devastating emergent event associated with high mortality and morbidity. Survivors usually experience functional neurological sequelae caused by vasospasm-related delayed ischemia. In this study, male Sprague-Dawley rats were randomly assigned to five groups: sham (non-SAH) group, SAH group, and three groups with SAH treated with different doses of valproic acid (VPA) (10, 20, 40 mg/kg, once-daily, for 7 days). The severity of vasospasm was determined by the ratio of cross-sectional areas to intima-media thickness of the basilar arteries (BA) on the seventh day after SAH. The BA showed decreased expression of phospho-Akt proteins. The dentate gyrus showed increased expression of cleaved caspase-3 and Bax proteins and decreased expression of Bcl-2, phospho-ERK 1/2, phospho-Akt and acetyl-histone H3 proteins. The incidence of SAH-induced vasospasm was significantly lower in the SAH group treated with VPA 40 mg/kg (p < 0.001). Moreover, all groups treated with VPA showed reversal of the above-mentioned protein expression in BA and the dentate gyrus. Treatment with VPA upregulated histone H3 acetylation and conferred anti-vasospastic and neuro-protective effects by enhancing Akt and/or ERK phosphorylation. This study demonstrated that VPA could alleviate delayed cerebral vasospasm induced neuro-apoptosis after SAH.

Two Similar Cases of a Misdiagnosed Anterior Communicating Aneurysm Rupture

The misdiagnosis of a ruptured aneurysm directly endangers patient's life and health due to the high risk of rebleeding and its sequelae. In this paper, we present two uncommon cases of anterior communicating artery aneurysm rupture with a relatively small intracerebral bleeding, seemingly without a diffuse subarachnoid hemorrhage (SAH), and a relatively mild clinical presentation. In these cases, the initial diagnosis failed, leading to missed aneurysmal ruptures. The atypical or mild clinical presentation, and the absence of SAH on computed tomography (CT) and/or magnetic resonance imaging (MRI) scan or absent blood in the cerebrospinal fluid (CSF) are all factors which could lead to a false or delayed diagnosis. Meticulous evaluation of patient's symptoms, CT, MRI scans, and CSF findings are mandatory. The possibility of a small blood clot without a diffuse SAH must be considered.

Cerebral aneurysm rupture status classification using statistical and machine learning methods

Morphological characterization and fluid dynamics simulations were carried out to classify the rupture status of 71 (36 unruptured, 35 ruptured) patient specific cerebral aneurysms using a machine learning approach together with statistical techniques. Eleven morphological and six hemodynamic parameters were evaluated individually and collectively for significance as rupture status predictors. The performance of each parameter was inspected using hypothesis testing, accuracy, confusion matrix, and the area under the receiver operating characteristic curve. Overall, the size ratio exhibited the best performance, followed by the diastolic wall shear stress, and systolic wall shear stress. The prediction capability of all 17 parameters together was evaluated using eight different machine learning algorithms. The logistic regression achieved the highest accuracy (0.75), whereas the random forest had the highest area under curve value among all the classifiers (0.82), surpassing the performance exhibited by the size ratio. Hence, we propose the random forest model as a tool that can help improve the rupture status prediction of cerebral aneurysms.

Microsurgical Clipping of a Posterior Inferior Cerebellar Artery Aneurysm Following Failed Pipeline Stent

Aneurysms of the posterior inferior cerebellar artery (PICA) are rare, with limited consensus on appropriate management. These aneurysms have been noted to have a faster growth rate and are more prone to rupture. Accessing these aneurysms for microsurgical clipping is challenging, and has traditionally required significant removal of the occipital condyle, putting the patient at risk for future complications. Therefore, some have opted to utilize minimally invasive techniques such as a pipeline stent, though these methods can fail to cause complete occlusion of the aneurysm. The current case describes a patient who was found to have a PICA aneurysm that was initially managed with a pipeline stent. However, upon further follow up, the aneurysm showed continued filling, leading to the decision to clip the aneurysm. In this case, we describe the use of a far lateral approach for accessing and clipping a PICA aneurysm with minimal removal of the occipital condyle. The patient successfully tolerated the surgery and was discharged home. 

Protocatechuic acid attenuates cerebral aneurysm formation and progression by inhibiting TNF-alpha/Nrf-2/NF-kB-mediated inflammatory mechanisms in experimental rats

Our current research aims to examine whether protocatechuic acid (PCA) can be used as a therapeutic agent for the development of cerebral aneurysm (CA) and to elucidate the mechanisms behind this. We assessed the effects of PCA at 50 and 100 mg/kg on the activation of signaling pathways for tissue necrosis factor (TNF)-α/nuclear factor (NF)-κB/nuclear factor erythroid 2 (Nrf-2) on progression and development in an elastase-induced CA model, accompanied by a high-salt diet to induce hypertension. The expression of inflammatory cytokines, chemokines, tumor necrosis factor-α, interleukins (IL)-8, IL-17, IL-6, IL-1β, and matrix metalloproteinase (MMP)-2 and MMP-9 was analyzed by ELISA, western blot, and reverse transcriptase quantative polymerase chain reaction. The expression levels of antioxidant enzymes and translocation of Nrf-2 were also determined. The group treated with PCA demonstrated a significant (P < 0.05) decrease in the aneurysmal size in rats compared to the CA-induced group. We found that PCA treatment suppressed the invasion of macrophage and activation of TNF-α/NF-κB/Nrf-2 signaling pathways. There was a significant decrease (P < 0.05) in pro-inflammatory cytokine and chemokine levels in a dose-dependent manner. We found that PCA treatment exerts protective effects by suppressing the development and progression of CA through the inhibition of inflammatory responses in macrophages via TNF-α/NF-κB/Nrf-2 signaling pathways, thus demonstrating that PCA can act as a treatment for CA.

Numerical study on the energy cascade of pulsatile Newtonian and power-law flow models in an ICA bifurcation

The complex physics and biology underlying intracranial hemodynamics are yet to be fully revealed. A fully resolved direct numerical simulation (DNS) study has been performed to identify the intrinsic flow dynamics in an idealized carotid bifurcation model. To shed the light on the significance of considering blood shear-thinning properties, the power-law model is compared to the commonly used Newtonian viscosity hypothesis. We scrutinize the kinetic energy cascade (KEC) rates in the Fourier domain and the vortex structure of both fluid models and examine the impact of the power-law viscosity model. The flow intrinsically contains coherent structures which has frequencies corresponding to the boundary frequency, which could be associated with the regulation of endothelial cells. From the proposed comparative study, it is found that KEC rates and the vortex-identification are significantly influenced by the shear-thinning blood properties. Conclusively, from the obtained results, it is found that neglecting the non-Newtonian behavior could lead to underestimation of the hemodynamic parameters at low Reynolds number and overestimation of the hemodynamic parameters by increasing the Reynolds number. In addition, we provide physical insight and discussion onto the hemodynamics associated with endothelial dysfunction which plays significant role in the pathogenesis of intracranial aneurysms.

Nomogram for Stability Stratification of Small Intracranial Aneurysm Based on Clinical and Morphological Risk Factors

Background and Purpose: Stability stratification of intracranial aneurysms (IAs) is crucial for individualized clinical management, especially for small IAs. We aim to develop and validate a nomogram based on clinical and morphological risk factors for individualized instability stratification of small IAs.

Methods: Six hundred fifty-eight patients with unstable (n = 293) and stable (n = 416) IAs <7 mm were randomly divided into derivation and validation cohorts. Twelve clinical risk factors and 18 aneurysm morphological risk factors were extracted. Combined with important risk factors, a clinical-morphological predictive nomogram was developed. The nomogram performance was evaluated in the derivation and the validation cohorts in terms of discrimination, calibration, and clinical usefulness.

Results: Five independent instability-related risk factors were included in the nomogram: location, irregularity, side/bifurcation type, flow angle, and height-to-width ratio. In the derivation cohort, the area under the curve (95% CI) of the nomogram was 0.803 (95% CI, 0.764–0.842), and good agreement between predicted instability risk and actual instability status could be detected in the calibration plot. The nomogram also exhibited good discriminations and calibration in the validation cohort: the area under the curve (95% CI) was 0.744 (95% CI, 0.677–0.812). Small IAs with scores <90 were considered to have low risk of instability, and those with scores of 90 or greater were considered to have high risk of instability.

Conclusions: The nomogram based on clinical and morphological risk factors can be used as a convenient tool to facilitate individualized decision-making in the management of small IAs.

The association of CDKN2BAS gene polymorphisms and intracranial aneurysm: A meta-analysis

Intracranial aneurysm (IA) is one of the main causes of subarachnoid hemorrhage (SAH) leading to a high percentage of disability and mortality worldwide. In addition to environmental factors, the risk of rupture or prognosis of intracranial aneurysm is also closely related to gene. Thus, a lot of genetic studies have been used to explore associated risk genes as well as variant loci of intracranial aneurysm and found several chromosome variates including 9p21.3 (CDKN2BAS) related to Intracranial aneurysm. However, due to differences in population and the existence of SNP, it is still not determined that whether these genetic changes can be identified as independent risk factors for intracranial aneurysm. Therefore, we performed a meta-analysis of CDKN2BAS SNPs to explore its association with intracranial aneurysms and the results show a significance relation between rs10757272, rs1333040, and rs6475606 with intracranial aneurysm. This will open a new perspective for future intracranial aneurysm gene research and therapy.

Risk Factors for Higher Volume of Hemorrhage in Ruptured Anterior Circulation Intracranial Aneurysms

Purpose: To explore the influencing factors of volume hemorrhage in ruptured anterior circulation aneurysms, so as to identify the characteristics of anterior circulation aneurysms with high volume of hemorrhage, and to provide advice for clinical diagnosis and treatment for those aneurysms. Methods: We retrospectively reviewed 437 cases of ruptured anterior intracranial aneurysms in our center between the years 2012 and 2017. According to the inclusion criteria, a total of 100 qualified patients were screened out. We collected demographic characteristics, environmental exposure, and admission status of enrolled patients. In addition, morphological parameters and location of aneurysms were also included. The semiautomatic threshold method was used to measure the volume of hemorrhage. According to the results, the patients were divided into the group with high blood volume and low blood volume. Univariate and multivariate logistic regression analyses were used to discover the related factors affecting the bleeding volume. Results: In univariable analysis, pulse pressure (P = 0.014) showed a significant difference at the P < 0.05 test level. In terms of aneurysm morphology, the irregular shape (P < 0.001), calcification (P = 0.001), and flow angle (P = 0.006) showed significant statistical differences between the two groups at the P < 0.01 level (P < 0.01). Multivariate logistic regression analysis showed that irregular shape (OR = 5.370 P = 0.002 < 0.05), large flow angle (OR = 1.033 P = 0.016 < 0.05), and calcification (OR = 5.460 P = 0.003 < 0.05) were risk factors for volume of hemorrhage in ruptured anterior circulation aneurysms. The influence of hypertension history was at critical state (OR = 2.877 P = 0.051 > 005). Conclusions: According to our analysis results, intracranial anterior circulation aneurysms with irregular shapes, calcifications, and large flow angle are more dangerous. Aneurysms with these characteristics often have a large amount of hemorrhage, requiring timely treatment in clinical practice.

Multiple and mirror intracranial aneurysms: study of prevalence and associated risk factors

OBJECTIVE

Multiple intracranial aneurysms (MIA) account for 30% of all intracranial aneurysms, while mirror aneurysms, a subgroup of MIA, are present in 5% of all patients with cerebral aneurysms. We investigated the risk factors associated with the presence of multiple and mirror intracranial aneurysms.

METHODS

1404 patients, 314 males (22.4%) and 1090 female (77.6%) were enrolled for this study. Diagnosis was performed with a digital subtraction angiography (DSA). Multiplicity was defined as the presence of two or more aneurysms and mirror aneurysms as one pair of aneurysms involving bilateral corresponding arteries. Patients were followed-up from September 2009 till August 2018. Individuals' characteristics such as sex, age, smoking, hypertension and use of contraceptives were evaluated.

RESULTS

Five hundred and twelve patients (36.4%) were diagnosed with MIA, approximately 4%/year. We observed 203 pairs of mirror aneurysms, accounting for 406 aneurysms (13% of the population). There was an increased frequency of females with multiple (p < 0.001, OR = 1.883, 95% CI = 1.386-2.560) and mirror aneurysms (p < 0.001, OR = 2.828, 95% CI = 1.725-4.636). Smoking was associated with multiplicity (p< 0.001, OR = 1.458, 95% CI = 1.160-1.833), as well as advanced age (p < 0.001, OR = 1.938, 95% CI = 1.438-2.611), but there was no significant relation with presence of mirror aneurysms. We observed higher frequency of baby aneurysms (<3mm) in the group of patients with MIA, while giant aneurysms (>25 mm) were most found in patients with only one aneurysm (p < 0.001). No differences between patients who used contraceptives against patients who did not use were found (p = 0.600).

CONCLUSIONS

Gender and smoking, known risk factors to the development of a single intracranial aneurysm, are proportionally increased in patients with MIA. Hypertension and oral contraceptives were not associated with multiplicity.

Institutional Experience of Microsurgical Management in Posterior Circulation Aneurysm

Introduction:

Posterior circulation aneurysm constitutes 15%–20% of all intracerebral aneurysms. With the advancement of endovascular techniques, the microsurgery for posterior circulation aneurysms has been pushed back a little. Even the International Subarachnoid Aneurysmal Trial gave support to the concepts of endovascular procedures, but microsurgical modality should not be discouraged. We present our institutional experience of microsurgical techniques on posterior circulation aneurysms.

Materials and Methods:

We performed a retrospective analysis of 37 patients of posterior circulation aneurysm from 2015 to 2019, referred to Bantane Hospital, Japan. We included all posterior circulation aneurysms such as basilar tip, basilar trunk, and vertebral artery-posterior inferior cerebellar artery (VA-PICA) aneurysms, admitted and treated with clipping or bypass and trapping. We assessed the outcome as measured by modified Rankin Score (mRS), complications, and mortality.

Results:

Out of 37 patients, 10 cases were a basilar tip, one case was the basilar trunk, and 26 cases were VA-PICA aneurysm. Intraoperatively, neuromonitoring, indocyanine green dye, dual-image videoangiography (DIVA), and neuro endoscope were used. Two patients of basilar tip aneurysm developed third cranial nerve paresis and six patients of VA-PICA aneurysm developed lower cranial nerve paresis which resolved spontaneously. All the patients were discharged with mRS of 0 or 1. No mortality was recorded in our study.

Conclusion:

Microsurgical clipping of posterior circulation aneurysm is safe in unruptured aneurysm with a very low risk of mortality and morbidity under experienced hands. All postoperative complications in our study were transient and resolved with time with no residual deficits. Preoperative simulation, intraoperative neuromonitoring, DIVA, and neuro endoscope help achieve complete obliteration of aneurysmal sac and avoid complications.

Surrounding vascular geometry associated with basilar tip aneurysm formation

Hemodynamic stress is thought to play an important role in the formation of intracranial aneurysms, which is conditioned by the geometry of the surrounding vasculature. Our goal was to identify image-based morphological parameters that were associated with basilar artery tip aneurysms (BTA) in a location-specific manner. Three-dimensional morphological parameters obtained from CT-angiography (CTA) or digital subtraction angiography (DSA) from 207 patients with BTAs and a control group of 106 patients with aneurysms elsewhere to control for non-morphological factors, who were diagnosed at the Brigham and Women's Hospital and Massachusetts General Hospital between 1990 and 2016, were evaluated. We examined the presence of hypoplastic, aplastic or fetal PCoAs, vertebral dominance, and diameters and angles of surrounding parent and daughter vessels. Univariable and multivariable statistical analyses were performed to determine statistical significance. Sensitivity analyses with small (≤ 3 mm) aneurysms only and with angles excluded, were also performed. In multivariable analysis, daughter-daughter angle was directly, and parent artery diameter and diameter size ratio were inversely associated with BTAs. These results remained significant in the subgroup analysis of small aneurysms (width ≤ 3 mm) and when angles were excluded. These easily measurable and robust parameters that are unlikely to be affected by aneurysm formation could aid in risk stratification for the formation of BTAs in high-risk patients.

Management of unruptured incidentally found intracranial saccular aneurysms

Unruptured intracranial saccular aneurysms occur in 3-5% of the general population. As the use of diagnostic medical imaging has steadily increased over the past few decades with the increased availability of computed tomography (CT) and magnetic resonance imaging (MRI), so has the detection of incidental aneurysms. The management of an unruptured intracranial saccular aneurysm is challenging for both patients and physicians, as the decision to intervene must weigh the risk of rupture and resultant subarachnoid hemorrhage against the risk inherent to the surgical or endovascular procedure. The purpose of this paper is to provide an overview of factors to be considered in the decision to offer treatment for unruptured intracranial aneurysms in adults. In addition, we review aneurysm and patient characteristics that favor surgical clipping over endovascular intervention and vice versa. Finally, the authors propose a novel, simple, and clinically relevant algorithm for observation versus intervention in unruptured intracranial aneurysms based on the PHASES scoring system.

Role of matrix metalloproteinases in the pathogenesis of intracranial aneurysms

Intracranial aneurysms (IAs) are a result of complex interactions between biochemical and mechanical forces and can lead to significant morbidity if they rupture and cause subarachnoid hemorrhage. This review explores the role of matrix metalloproteinases (MMPs) in the pathogenesis and progression of IAs. In addition to providing a review of the normal function of MMPs, it is intended to explore the interaction between inflammation and abnormal blood flow and the resultant pathological vascular remodeling processes seen in the development and rupture of IAs. Also reviewed is the potential for the use of MMPs as a diagnostic tool for assessment of aneurysm development and progression.

Rare pathology leading to a diagnostic challenge: A subarachnoid spinal hematoma after catheter cryoablation for atrial fibrillation

Catheter ablation for atrial fibrillation is associated with a low rate of complications, with few reports of intracranial hemorrhage in the literature. Additionally, subarachnoid hemorrhage with spinal hematoma is also an uncommon pathology with less than 200 total cases to date described. A 78-year-old female with hypertension and atrial fibrillation on warfarin presented for catheter cryoablation and experienced periprocedural hypertension. Subsequently, post-procedure, the patient developed severe back pain, nausea, vomiting, altered consciousness, and paraplegia. Imaging demonstrated subarachnoid hemorrhage with hematoma compressing cord at the T4/5 level and infarction inferior to this level. The rare nature as well as presentation of this pathology, in the setting of a safe procedure, emphasizes the importance to re-evaluate diagnostic plans when patient presentation is inconsistent with expected post procedural course. 〈Learning objective: The rare nature as well as presentation of subarachnoid hemorrhage with spinal hematoma, in the setting of a safe catheter cryoablation for atrial fibrillation, emphasizes the importance to re-evaluate diagnostic plans when patient presentation is inconsistent with expected post procedural course.〉.

Hemodynamics of Cerebral Aneurysms: Connecting Medical Imaging and Biomechanical Analysis

In the last two decades, numerous studies have conducted patient-specific computations of blood flow dynamics in cerebral aneurysms and reported correlations between various hemodynamic metrics and aneurysmal disease progression or treatment outcomes. Nevertheless, intra-aneurysmal flow analysis has not been adopted in current clinical practice, and hemodynamic factors usually are not considered in clinical decision making. This review presents the state of the art in cerebral aneurysm imaging and image-based modeling, discussing the advantages and limitations of each approach and focusing on the translational value of hemodynamic analysis. Combining imaging and modeling data obtained from different flow modalities can improve the accuracy and fidelity of resulting velocity fields and flow-derived factors that are thought to affect aneurysmal disease progression. It is expected that predictive models utilizing hemodynamic factors in combination with patient medical history and morphological data will outperform current risk scores and treatment guidelines. Possible future directions include novel approaches enabling data assimilation and multimodality analysis of cerebral aneurysm hemodynamics.

[Influence of genetics in intracranial aneurysms]

BACKGROUND

The prevalence of unruptured intracranial aneurysms is approximately 3-5%. Subarachnoid hemorrhage caused by rupture of an aneurysm often affects middle-aged people and harbors high morbidity and mortality. The increasing availability of noninvasive imaging techniques over time is accompanied by an increase in the incidental detection of aneurysms.

METHODS

The etiology in aneurysm development is heterogeneous. Besides polygenic multifactorial diseases, often triggered by well-established vascular risk factors, monogenic diseases should also be considered. Advances in genetics has helped to identify genes that contribute to the risk of intracranial aneurysm development.

CONCLUSION

The genetic basis of intracranial aneurysms shows a broad heterogeneity and complexity. Currently, besides imaging there is no reliable diagnostic test to identify patients who are at higher risk for asymptomatic intracranial aneurysms.

Prevalence of Intracranial Aneurysms in Patients With Systemic Vessel Aneurysms: A Nationwide Cohort Study

Background and Purpose- Most aneurysms are a focal manifestation of a systemic condition. Some reports have suggested genetic and environmental factors may play a role in pathogenesis. The aim of the present study was to evaluate the prevalence of intracranial aneurysms (IA) in a large cohort of patients with other systemic vessel aneurysms and dissections (OVAD) and identify potential risk factors for IA in this population. Methods- We defined OVAD as systemic vessel aneurysms, excluding aortic dissections and aneurysms. A cohort of 1.1 million patients was extracted from the population-based cohort from the Korea National Health Insurance Service, which holds almost all medical data including diagnostic codes, procedures, and personal information. Using χ² or Fisher exact test, the prevalence of the IA concerning OVAD status was analyzed. Results- In OVAD individuals, 25.7% (261/1017) of patients had been concurrently diagnosed with IA. The odds ratios for having concurrent IA in patients with OVAD were 56.31 (95% CI, 48.821-64.949; P=0.000). OVAD patients with dyslipidemia were >7× likely to be affected by IA (adjusted odds ratio, 7.7 [95% CI, 6.59-9.01]; P=0.000). Hypertension, diabetes mellitus, old age (>60 years), and male sex had increased odds for having concurrent IA by 5.89, 3.48, 1.83, and 1.35, respectively. Subgroup analysis with socioeconomic or disability revealed that the prevalence of IA was significantly higher in all groups. Uncertainty regarding the temporal sequence of onset and lack of detail on disease severity and subtype prevented more conclusive results. Conclusions- Patients with OVAD have a higher prevalence of IA than control groups. Therefore, we may approach aneurysms as systemic disease, and further investigations about their pathophysiology must follow.

Potential Influences of Gut Microbiota on the Formation of Intracranial Aneurysm

Gut microbiota modulates metabolic and immunoregulatory axes and contributes to the pathophysiology of diseases with inflammatory components, such as atherosclerosis, diabetes mellitus, and ischemic stroke. Inflammation is emerging as a critical player in the pathophysiology of an intracranial aneurysm. Therefore, we hypothesized that the gut microbiota affects aneurysm formation by modulating inflammation. We induced intracranial aneurysms in mice by combining systemic hypertension and a single injection of elastase into the cerebrospinal fluid. Depletion of the gut microbiota was achieved via an oral antibiotic cocktail of vancomycin, metronidazole, ampicillin, and neomycin. Antibiotics were given 3 weeks before aneurysm induction and either continued until the end of the experiment or stopped 1 day before aneurysm induction. We also assessed the effects of the gut microbiota depletion on macrophage infiltration and mRNA levels of inflammatory cytokines. Gut microbiota depletion by antibiotics reduced the incidence when antibiotics were started 3 weeks before aneurysm induction and continued until the end of the experiment (83% versus 6%, P<0.001). Even when antibiotics were stopped 1 day before aneurysm induction, the gut microbiota depletion significantly reduced the incidence of aneurysms (86% versus 28%, P<0.05). Both macrophage infiltration and mRNA levels of inflammatory cytokines were reduced with gut microbiota depletion. These findings suggest that the gut microbiota contributes to the pathophysiology of aneurysms by modulating inflammation. Human studies are needed to determine the exact contribution of the gut microbiota to the pathophysiology of aneurysm formation and disease course in humans.

Causes, Predictors, and Trends of Unplanned Readmissions after Elective Endovascular Embolization of Cerebral Aneurysms

BACKGROUND

30- and 90-day readmissions (dRA) are being increasingly scrutinized as quality metrics for hospital and provider performances. Little information regarding risk factors for readmission after elective endovascular treatment (EVT) of an unruptured cerebral aneurysm (UCA) is available.

METHODS

The Nationwide Readmissions Database was used to identify patients who underwent elective endovascular embolization of an unruptured aneurysm between 2010 and 2014. The primary outcomes of interest were unplanned readmissions occurring within 30 or 90 days of discharge. Binary logistic regressions were used to identify variables related to patients' demographics, comorbidities, and index hospital admission that were associated with 30dRA and 90dRA.

RESULTS

A total of 8588 patients met the inclusion criteria for 30dRA analysis and 7289 patients were eligible for 90dRA analysis. The 5-year 30dRA and 90dRA readmission rates were 7.1% and 13.5%, respectively. The annual incidences of 30dRAs and 90dRAs between 2010 and 2014 decreased significantly (pooled odds ratio (OR) for 30dRA: .874, 95% confidence interval (CI) .765-.998; pooled OR for 90dRA: .841, 95% CI .755-.938). Patients in higher income quartiles experienced decreased odds of 30dRA and 90dRA. Nonroutine disposition following the index admission and greater comorbidity burdens were associated with higher likelihoods of both 30dRA and 90dRA. The presence of pulmonary or cardiac complications was associated with increased odds of 90dRA.

CONCLUSION

Readmission rates after elective EVT of UCAs decreased between 2010 and 2014. We identified several novel risk factors for both 30dRAs and 90dRAs that can be used to identify patients who are at highest risk of readmission.

Characteristics of Unruptured Compared to Ruptured Intracranial Aneurysms: A Multicenter Case-Control Study

BACKGROUND

Only a minority of intracranial aneurysms rupture to cause subarachnoid hemorrhage.

OBJECTIVE

To test the hypothesis that unruptured aneurysms have different characteristics and risk factor profiles compared to ruptured aneurysms.

METHODS

We recruited patients with unruptured aneurysms or aneurysmal subarachnoid hemorrhages at 22 UK hospitals between 2011 and 2014. Demographic, clinical, and imaging data were collected using standardized case report forms. We compared risk factors using multivariable logistic regression.

RESULTS

A total of 2334 patients (1729 with aneurysmal subarachnoid hemorrhage, 605 with unruptured aneurysms) were included (mean age 54.22 yr). In multivariable analyses, the following variables were independently associated with rupture status: black ethnicity (odds ratio [OR] 2.42; 95% confidence interval [CI] 1.29-4.56, compared to white) and aneurysm location (anterior cerebral artery/anterior communicating artery [OR 3.21; 95% CI 2.34-4.40], posterior communicating artery [OR 3.92; 95% CI 2.67-5.74], or posterior circulation [OR 3.12; 95% CI 2.08-4.70], compared to middle cerebral artery). The following variables were inversely associated with rupture status: antihypertensive medication (OR 0.65; 95% CI 0.49-0.84), hypercholesterolemia (0.64 OR; 95% CI 0.48-0.85), aspirin use (OR 0.28; 95% CI 0.20-0.40), internal carotid artery location (OR 0.53; 95% CI 0.38-0.75), and aneurysm size (per mm increase; OR 0.76; 95% CI 0.69-0.84).

CONCLUSION

We show substantial differences in patient and aneurysm characteristics between ruptured and unruptured aneurysms. These findings support the hypothesis that different pathological mechanisms are involved in the formation of ruptured aneurysms and incidentally detected unruptured aneurysms. The potential protective effect of aspirin might justify randomized prevention trials in patients with unruptured aneurysms.

Does Systemic Hypertension Impact Recanalization of Coiled Aneurysms?

PURPOSE

It is well known that hypertension is a significant factor in the formation, growth, and rupture of aneurysms and recanalization of coiled aneurysms is affected by hemodynamic stress. At present, however, the impact of hypertension on recanalization of coiled aneurysms has not been adequately investigated. This study examined the relation between hypertension and subsequent outcomes of coiled aneurysms, using a matched patient analysis.

METHODS

A total of 715 subjects undergoing coil embolization of intracranial aneurysms between 2011 and 2013 were selected for study. Time-of-flight magnetic resonance or conventional angiography was used (singly or together) to gauge degrees of occlusion after coiling, applying the Raymond classification in grading recanalization. Patients with hypertension were grouped as controlled or uncontrolled, based on blood pressure readings at outpatient clinics. Hypertensive and non-hypertensive subjects were matched (1:1) for several relevant variables.

RESULTS

Overall, 484 patients (67.7%) were hypertensive (controlled 338; uncontrolled 146). During the follow-up period (28.6 ± 9.7 months), 129 aneurysms (18.0%) displayed recanalization (minor 58; major 71). Patient age, concomitant diabetes, hyperlipidemia, aneurysm size, neck size, depth-to-neck ratio, and aneurysm type differed significantly in hypertensive and non-hypertensive groups; however, group incidences of cumulative recanalization were similar (p = 0.297). After 1:1 matching the cumulative recanalization rate (13.5%) in hypertensive and non-hypertensive counterparts (14.3%) again proved similar (p = 0.578). In the hypertensive group, in addition, recanalization showed no relation to controlled and uncontrolled subgroup (odds ratio, OR = 1.000, p > 0.999).

CONCLUSION

Unlike other aspects of evolving aneurysms (e.g. formation, growth, or rupture), recanalization of coiled aneurysms seems to be unaffected by systemic hypertension.

Dental Pulp Stem Cell-Derived Factors Alleviate Subarachnoid Hemorrhage-Induced Neuroinflammation and Ischemic Neurological Deficits

Aneurysmal subarachnoid hemorrhage (aSAH), characterized by the extravasation of blood into the subarachnoid space caused by an intracranial aneurysm rupture, may lead to neurocognitive impairments and permanent disability and usually carries poor outcome. Dental or gingiva-derived stem cells have been shown to contribute to immune modulation and neuroregeneration, but the underlying mechanisms are unclear. In the present study, we sought to investigate whether dental pulp stem cells (DPSCs) secrete certain factor(s) that can ameliorate the neural damage and other manifestations in a rat aSAH model. Twenty-four hours after the induction of aSAH, microthrombosis, cortical vasoconstriction, and the decrease in microcirculation and tissue oxygen pressure were detected. Intrathecal administration of DPSC-derived conditioned media (DPSC-CM) ameliorated aSAH-induced vasoconstriction, neuroinflammation, and improved the oxygenation in the injured brain. Rotarod test revealed that the aSAH-induced cognitive and motor impairments were significantly improved by this DPSC-CM administration. Cytokine array indicated the major constituent of DPSC-CM was predominantly insulin growth factor-1 (IGF-1). Immunohistochemistry staining of injured brain tissue revealed the robust increase in Iba1-positive cells that were also ameliorated by DPSC-CM administration. Antibody-mediated neutralization of IGF-1 moderately deteriorated the rescuing effect of DPSC-CM on microcirculation, Iba1-positive cells in the injured brain area, and the cognitive/motor impairments. Taken together, the DPSC-derived secretory factors showed prominent therapeutic potential for aSAH. This therapeutic efficacy may include improvement of microcirculation, alleviation of neuroinflammation, and microglial activation; partially through IGF-1-dependent mechanisms.

Differences in Pressure Within the Sac of Human Ruptured and Nonruptured Cerebral Aneurysms

BACKGROUND

Hemodynamics plays a critical role in the development, growth, and rupture of intracranial aneurysms. This data could be vital in determining individual aneurysm rupture risk and could facilitate our understanding of aneurysms.

OBJECTIVE

To present the largest prospective cross-sectional cohort study of intrasaccular pressure recordings of ruptured and nonruptured intracranial aneurysms and describe the hemodynamic differences that exist between ruptured and nonruptured aneurysms.

METHODS

During endovascular treatment, a standard 1.8-Fr 200 m length microcatheter was navigated into the dome of the aneurysm prior to coil embolization. With the microcatheter centralized within the dome of the aneurysm, an arterial pressure transducer was attached to the proximal end of the microcatheter to measure the stump pressure inside the aneurysm dome.

RESULTS

In 68 aneurysms (28 ruptured, 40 nonruptured), we observed that ruptured cerebral aneurysms had a lower systolic and mean arterial pressure compared to nonruptured cohort (P = .0008). Additionally, the pulse pressures within the dome of ruptured aneurysms were significantly more narrow than that of unruptured aneurysms (P = .0001). These findings suggest that there may be an inherent difference between ruptured and nonruptured aneurysms and such recordings obtained during routine digital subtraction angiography could potentially become a widely applied technique to augment risk stratification of aneurysms.

CONCLUSION

Our preliminary data present new evidence distinguishing ruptured from unruptured aneurysms that may have a critical role as a predictive parameter to stratify the natural history of nonruptured intracranial aneurysms and as a new avenue for future investigation.

Evaluation of Safety and Successfulness of the Coil Embolization of Intracranial Aneurysms

Intracranial aneurisms are ongoing problem for neurosurgeons and especially for interventional neuroradiologists due to its morbidity and mortality. The method of choice for treatment of the unruptured and ruptured intracranial aneurysms is endovascular coiling on account of its minimal invasiveness and high effectiveness. The aim of our study was to evaluate the safety and successfulness of endovascular coiling procedure in unruptured and ruptured intracranial aneurysms.

Our study was designed as case series and consisted of patients older than 18 years, who underwent endovascular coiling of unruptured and ruptured intracranial aneurysms and follow-up examination 6 months after the interventional procedure. The procedures were performed from December 2010 to December 2016, by experienced interventional neuroradilogists (more than 400 performed embolizations each) at the Department for Interventional Neuroradiology, Clinical Center Kragujevac, Serbia.

There were 681 patients (average age 47.5 ± 11.2 years) treated with endovascular coiling, out of them 324 (234 females, 90 males) had unruptured intracranial aneurysm and 357 (138 females, 219 males) had ruptured intracranial aneurysm. In our series, total complication rate was 11.71 %. Analysis of the results after first endovascular procedure has shown that complete aneurysm occlusion was accomplished in 546 patients (80.3%), near-complete in 81 patients (11.8%), and incomplete in 54 patients (7.9 %).

Our results were satisfying regarding the procedure’s success, safety, outcomes and study material. However, further technical development of the materials and constant training of the interventional radiologists, are a necessity in order to improve treatment outcomes and patients’ benefit.

A Nationwide Analysis of 30-Day and 90-Day Readmissions After Elective Cerebral Aneurysm Clipping in the United States: Causes, Predictors, and Trends

BACKGROUND

Thirty-day readmissions (30dRAs) and 90-day readmissions (90dRAs) are being increasingly scrutinized as quality metrics for hospital and provider performances. Little information regarding risk factors for 30dRA and 90dRA after elective cerebral aneurysm clipping (CAC) of unruptured cerebral aneurysms is available. We sought to characterize risk factors with a nationally representative administrative database.

METHODS

The Nationwide Readmissions Database was used to identify patients who underwent elective CAC between 2010 and 2014. The outcomes of interest were unplanned readmissions occurring within 30 or 90 days of discharge. Binary logistic regression was used to identify variables related to patients' demographics, comorbidities, and index hospital admission that were associated with readmission. A Cochran-Mantel-Haenszel test was used to evaluate for changes in annual readmission rates.

RESULTS

A total of 1123 patients met the inclusion criteria for 30dRA analysis and 946 patients were eligible for 90dRA analysis. The 5-year 30dRA and 90dRA readmission rates were 9.1% and 14.9%, respectively. The annual rate of readmission between 2010 and 2014 did not change. Greater Charlson Comorbidity Index (odds ratio [OR], 2.68; 95% confidence interval [CI], 1.14-6.28) and nonroutine discharge after the index admission (OR, 1.81; 95% CI, 1.04-3.14) were associated with greater odds of 30dRA. Charlson Comorbidity Index (OR, 3.45; 95% CI, 1.57-7.56) and treatment at a metropolitan teaching hospital (OR, 2.21; 95% CI, 1.06-4.60) were associated with increased odds of 90dRA. Wound infection was the most common reason for readmission.

CONCLUSIONS

Readmission rates after elective CAC remained unchanged between 2010 and 2014, suggesting that improved methods for reducing unplanned readmissions after CAC are needed.

Nonsteroidal Anti-Inflammatory Drugs: A Potential Pharmacological Treatment for Intracranial Aneurysm

Background

Saccular intracranial aneurysms (IAs) are outpouchings of the vessel wall of intracranial arteries. Rupture of IAs results in subarachnoid hemorrhage which is associated with high morbidity and mortality. Surgical interventions, such as clipping and coiling, have associated risks. Currently, there are no proven pharmacological treatments to prevent the growth or rupture of IAs. Infiltration of proinflammatory cytokines in response to increased wall sheer stress is a hallmark of IA. Nonsteroidal anti-inflammatory drugs (NSAIDs) are being investigated as potential therapeutic agents for reduction in growth and/or prevention of IA through inhibition of inflammatory pathways.

Summary

This review will discuss the role of NSAIDs in attenuating the inflammation that drives IA progression and rupture. There are two main subtypes of NSAIDs, nonselective COX and selective COX-2 inhibitors, both of which have merit in treating IA. Evidence will be presented which shows that NSAIDs inhibit several key inflammatory mediators involved in IA progression including nuclear factor-κB, tumor necrosis factor-α, and matrix metalloproteinases. In addition, the role of NSAIDs in limiting inflammatory cell adhesion to endothelial cells and attenuating endothelial cell senescence will be discussed.

Key Messages

There is an abundance of basic science and preclinical data that support NSAIDs as a promising treatment for IA. Additionally, a combination treatment strategy of low-dose aspirin given concomitantly with a selective COX-2 inhibitor may result in a reduced side effect profile compared to aspirin or selective COX-2 inhibitor use alone. Several large clinical trials are currently planned to further investigate the efficacy of NSAIDs as an effective nonsurgical treatment for IAs.

Widening the spectrum of secondary headache: intracranial hypotension following a non-aneurysmal subarachnoid hemorrhage

BACKGROUND

Intracranial hypotension has been associated with a wide spectrum of neurological conditions including chronic non-aneurysmal and acute aneurysmal subarachnoid hemorrhage.

CASE

A 59-year-old man presented with a non-aneurysmal subarachnoid hemorrhage in a perimesencephalic pattern after a mild physical exertion. In the course of the disease, a magnetic resonance imaging of head and spine displayed intracranial hypotension that resolved spontaneously.

DISCUSSION

Long-standing intracranial hypotension has been reported as the cause of chronic subarachnoid hemorrhage and a single case of intracranial hypotension as the consequence of intracranial pressure fluctuations after acute aneurysmal subarachnoid hemorrhage has been described. This is the first description of intracranial hypotension caused by acute non-aneurysmal subarachnoid hemorrhage. We hypothesize that blood in the subarachnoid space could have determined a spine cerebrospinal fluid leak through intracranial pressure fluctuations or mechanical action, causing arachnoiditis and possibly a dural tear.

A Shape Memory Alloy-Based Miniaturized Actuator for Catheter Interventions

In the current scenario of endovascular intervention, surgeons have to manually navigate the catheter within the complex vasculature of the human body under the guidance of X-ray. This manual intervention upsurges the possibilities of vessel damage due to frequent contact between the catheter and vasculature wall. In this context, a shape memory alloy-based miniaturized actuator was proposed in this study with a specific aim to reduce vessel wall related damage by improving the bending motions of the guidewire tip in a semi-automatic fashion. The miniaturized actuator was integrated with a FDA-approved guidewire and tested within a patient-specific vascular network model to realize its feasibility in the real surgical environment. The results illustrate that the miniaturized actuator gives a bending angle over 23° and lateral displacement over 900 µm to the guide wire tip by which the guidewire can be navigated with precision and possible vessel damage during the catheter intervention can certainly be minimized. In addition to it, the dynamic responses of the presented actuator were further investigated through numerical simulation in conjunction with the analytic analysis.

Initial misdiagnosis of aneurysmal subarachnoid hemorrhage: associating factors and its prognosis

BACKGROUND

Predicting the fate of patients who are given a misdiagnosis of aneurysmal subarachnoid hemorrhage (aSAH) remains unclear. The purpose was to examine factors associated with initial misdiagnosis of aSAH and to investigate the impact of initial misdiagnosis of aSAH on clinical outcomes.

METHODS

Between January 2007 and December 2015, medical records and radiographic data for 3118 consecutive patients with aSAH were reviewed. There were 33 patients who had been documented with an initial misdiagnosis of aSAH, and all met the following criteria: (1) failure to correctly identify aSAH upon initial presentation to health care professionals; and 2) subsequently documented aSAH after the initial misdiagnosis. After applying exclusion criteria, remaining 2898 patients were included in the control group.

RESULTS

The most common cause of the misdiagnosis is failure to detect aSAH on the initial radiographic imaging. Misdiagnosis group showed lower initial Glasgow Coma Scale, better Hunt-Hess grade, and lower Fisher's grade. Logistic regression analysis showed that initial HH grade (OR, 0.216; p = 0.014), initial Fisher's grade (OR, 0.732; p = 0.036), and hospital type during initial contact (OR, 2.266; p = 0.042) were independently associated with misdiagnosis of aSAH.

CONCLUSIONS

Patients with initially good HH grade, lower Fisher's grade, and visiting non-teaching hospital for initial contact were at risk of being misdiagnosed. Misdiagnosis of aSAH in patients with initial good HH grade did affect clinical outcomes negatively. The rebleeding rate was not significantly different between two groups. However, the mortality rate due to rebleeding was higher in MisDx group than in non-MisDx group.

Intracranial aneurysms: Review of current science and management

Unruptured intracranial aneurysms often have a relatively benign clinical course. Frequently, they are found incidentally during workup for an underlying, possibly related or unrelated, symptom or condition. Overall, brain aneurysms are considered to have a relatively low annual risk of rupture. However, should it occur, aneurysmal subarachnoid hemorrhage can lead to significant morbidity and mortality. Our understanding of the natural history and treatment outcomes of cerebral aneurysms has significantly increased over the last few decades, but choosing the optimal management for each patient requires the careful consideration of numerous medical, clinical and anatomic factors. The purpose of this review is to help physicians and caregivers, who may participate in the diagnosis, counseling and triage of patients with brain aneurysms, understand the basic elements of decision making. We discuss natural history, risk factors, screening, presentation, diagnosis, and their implications on aneurysm management and long-term follow-up. We also provide an overview of the risks and benefits of currently available treatment options.

Dysregulation of microRNA‑23b‑3p contributes to the development of intracranial aneurysms by targeting phosphatase and tensin homolog

MicroRNA‑23b‑3p (miR‑23b‑3p) has been reported to be involved in the pathogenesis of a number of diseases, including non‑small cell lung cancer and gastric cancer, by acting on different signaling pathways. The present study aimed to understand the association between the miR‑23b‑3p level of intracranial aneurysms (IAs) and the mechanism involved. Computational analysis was used to search for the target of miR‑23b‑3p, and luciferase assay was used to validate the miRNA/target association. Western blot analysis and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) were used to determine the expression of miR‑23b‑3p and phosphatase and tensin homolog (PTEN), and their expression in smooth muscle cells (SMCs) treated with miRNA mimic or inhibitor. Firstly, an online miRNA database (www.mirdb.org) was searched using the 'seed sequence' located within the 3'‑untranslated region of the target gene, and then PTEN was validated as the direct target gene via a luciferase reporter assay system. The negative regulatory association between miR‑23b‑3p and PTEN was determined through the analysis of the relative luciferase activity. Additionally, RT-qPCR and western blot analysis was performed in order to assess the mRNA and protein expression levels of PTEN among IA (n=32) and control (n=17) groups or cells treated with scramble control, miR‑23b‑3p mimics, PTEN siRNA and miR‑23b‑3p inhibitors to verify the negative regulatory association between miR‑23b‑3p and PTEN. Experiments were then performed to investigate the effect of miR‑23b‑3p and PTEN on the viability and apoptosis of pulmonary artery SMCs (PASMCs). The results showed that cells transfected with miR‑23b‑3p inhibitors suppressed the viability of SMCs by promoting the apoptosis of the cells compared with that of the scramble controls, while cells transfected with miR‑23b‑3p mimics and PTEN siRNA enhanced the viability of VSMCs by inducing apoptosis. This indicated that miR‑23b‑3p negatively interfered with the viability of the cells, while PTEN positively interfered with the viability of the cells. In conclusion, PTEN was found to be a virtual target of miR‑23b‑3p, and a negative regulatory association existed between miR‑23b‑3p and PTEN. miR‑23b‑3p and PTEN interfered with the viability and apoptosis of SMCs.

Use of the stereoscopic virtual reality display system for the detection and characterization of intracranial aneurysms: A Icomparison with conventional computed tomography workstation and 3D rotational angiography

OBJECTIVE

This study aimed to compare the diagnostic performance of the stereoscopic virtual reality display system with the conventional computed tomography (CT) workstation and three-dimensional rotational angiography (3DRA) for intracranial aneurysm detection and characterization, with a focus on small aneurysms and those near the bone.

PATIENTS AND METHODS

First, 42 patients with suspected intracranial aneurysms underwent both 256-row CT angiography (CTA) and 3DRA. Volume rendering (VR) images were captured using the conventional CT workstation. Next, VR images were transferred to the stereoscopic virtual reality display system. Two radiologists independently assessed the results that were obtained using the conventional CT workstation and stereoscopic virtual reality display system. The 3DRA results were considered as the ultimate reference standard.

RESULTS

Based on 3DRA images, 38 aneurysms were confirmed in 42 patients. Two cases were misdiagnosed and 1 was missed when the traditional CT workstation was used. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of the conventional CT workstation were 94.7%, 85.7%, 97.3%, 75%, and99.3%, respectively, on a per-aneurysm basis. The stereoscopic virtual reality display system missed a case. The sensitivity, specificity, PPV, NPV, and accuracy of the stereoscopic virtual reality display system were 100%, 85.7%, 97.4%, 100%, and 97.8%, respectively. No difference was observed in the accuracy of the traditional CT workstation, stereoscopic virtual reality display system, and 3DRA in detecting aneurysms.

CONCLUSION

The stereoscopic virtual reality display system has some advantages in detecting small aneurysms and those near the bone. The virtual reality stereoscopic vision obtained through the system was found as a useful tool in intracranial aneurysm diagnosis and pre-operative 3D imaging.

Safety of antithrombotic therapy for patients with acute ischemic stroke harboring unruptured intracranial aneurysm

Background The safety of antithrombotic therapy for patients with acute ischemic stroke harboring unruptured intracranial aneurysms remains unclear. Aims This study was performed to determine whether treatment with antiplatelets, anticoagulants, or intravenous thrombolytic agents is safe for patients with acute ischemic stroke and unruptured intracranial aneurysms. Methods Among 9149 patients with acute ischemic stroke enrolled in the Fukuoka Stroke Registry from June 2007 to December 2014, 8857 patients with data on cerebrovascular imaging and three-month outcomes were included in this study. The frequency of adverse events, including intracranial hemorrhage, symptomatic intracranial hemorrhage, and in-hospital mortality, was compared between patients with and without unruptured intracranial aneurysms. The risk of a poor functional outcome (modified Rankin scale score of ≥3) at three months after stroke onset was estimated after adjusting for confounding factors by logistic regression analysis. Results Unruptured intracranial aneurysms were identified in 412 (4.7%) patients, and the mean diameter was 4.1 ± 3.2 mm. There was no significant difference in the frequency of any adverse events between patients with and without unruptured intracranial aneurysms among the overall patients or patients receiving antiplatelets, anticoagulants, or intravenous thrombolytic agents. The odds ratios of a poor functional outcome were not significantly higher in the presence of unruptured intracranial aneurysms, even in patients undergoing antiplatelet therapy, anticoagulation therapy, or intravenous thrombolysis. Conclusions These findings suggest that unruptured intracranial aneurysms are not associated with increased risks of adverse events or poor functional outcomes even after antithrombotic therapy for acute ischemic stroke. However, accumulation of cases is required to verify these findings.

A clinical study and meta-analysis of carotid stenosis with coexistent intracranial aneurysms

Carotid stenosis (CS) and intracranial aneurysms (IAs) may concur in one person. We studied the prevalence of IAs in CS patients in our retrospectively collected database and systematically reviewed this issue. Five hundred and fifty-seven CS (≥50%) patients confirmed by DSA in our hospital from 2010-06 to 2015-06 were screened for coexistent IAs. After searching the related literatures from English and Chinese journal literature databases, a meta-analysis was performed to pool the prevalence of CS with coexistent IAs. Subgroup analyses were performed to explore the causes of heterogeneity among studies. IAs were detected in 98(17.0%) out of the 577 CS patients. 12 literatures and the present study including a total of 6965 CS patients and 446 cases with coexistent IAs. The pooled prevalence of CS with coexistent IAs was 6.3% (95%CI: 4.2-8.3%) in all the CS patients. The pooled RR for female to male CS patients to have coexistent IAs was 1.67 (95%CI: 1.34-2.08, P = 0.000). 3 studies and the present study were carried out in Asian countries with a pooled prevalence of 10.8% (95%CI: 5.3-16.3%); 6 studies in European countries with 3.0% (95%CI: 2.2-3.7%); and 3 studies in USA with 6.0% (95%CI: 2.2-9.7%). There was a statistically significant difference between the three subgroups (P < 0.001). The prevalence of IAs in CS patients seems higher in our clinical study and the meta-analysis than in the general population and previously reported. The eastern and the women CS patients have a higher risk for coexistent IAs.

Impact of pulse pressure on cerebrovascular events leading to age-related cognitive decline

Aging is a modern concept: human life expectancy has more than doubled in less than 150 yr in Western countries. Longer life span, however, reveals age-related diseases, including cerebrovascular diseases. The vascular system is a prime target of aging: the "wear and tear" of large elastic arteries exposed to a lifelong pulsatile pressure causes arterial stiffening by fragmentation of elastin fibers and replacement by stiffer collagen. This arterial stiffening increases in return the amplitude of the pulse pressure (PP), its wave penetrating deeper into the microcirculation of low-resistance, high-flow organs such as the brain. Several studies have associated peripheral arterial stiffness responsible for the sustained increase in PP, with brain microvascular diseases such as cerebral small vessel disease, cortical gray matter thinning, white matter atrophy, and cognitive dysfunction in older individuals and prematurely in hypertensive and diabetic patients. The rarefaction of white matter is also associated with middle cerebral artery pulsatility that is strongly dependent on PP and artery stiffness. PP and brain damage are likely associated, but the sequence of mechanistic events has not been established. Elevated PP promotes endothelial dysfunction that may slowly develop in parallel with the accumulation of proinflammatory senescent cells and oxidative stress, generating cerebrovascular damage and remodeling, as well as brain structural changes. Here, we review data suggesting that age-related increased peripheral artery stiffness may promote the penetration of a high PP to cerebral microvessels, likely causing functional, structural, metabolic, and hemodynamic alterations that could ultimately promote neuronal dysfunction and cognitive decline.

Comparison Between CTA and Digital Subtraction Angiography in the Diagnosis of Ruptured Aneurysms

BACKGROUND

Computerized tomography angiography (CTA) is commonly used to diagnose ruptured cerebral aneurysms with sensitivities reported as high as 97% to 100%. Studies validating CTA accuracy in the setting of subarachnoid hemorrhage (SAH) are scarce and limited by small sample sizes.

OBJECTIVE

To evaluate the diagnostic accuracy of CTA in detecting intracranial aneurysms in the setting of SAH.

METHODS

A single-center, retrospective cohort of 643 patients was reviewed. A total of 401 patients were identified whose diagnostic workup included both CTA and confirmatory digital subtraction angiography (DSA). Aneurysms missed by CTA but diagnosed by DSA were further stratified by size and location.

RESULTS

Three hundred and thirty aneurysms were detected by CTA while DSA detected a total of 431 aneurysms. False positive CTA results were seen for 24 aneurysms. DSA identified 125 aneurysms that were missed by CTA and 83.2% of those were <5 mm in diameter. The sensitivity of CTA was 57.6% for aneurysms smaller than 5 mm in size, and 45% for aneurysms originating from the internal carotid artery. The overall sensitivity of CTA in the setting of SAH was 70.7%.

CONCLUSION

The accuracy of CTA in the diagnosis of ruptured intracranial aneurysm may be lower than previously reported. CTA has a low sensitivity for aneurysms less than 5 mm in size, in locations adjacent to bony structures, and for those arising from small caliber parent vessels. It is our recommendation that CTA should be used with caution when used alone in the diagnosis of ruptured intracranial aneurysms.