Integrative bioinformatics analysis of miRNA and mRNA expression profiles and identification of associated miRNA-mRNA network in intracranial aneurysms

Background

Intracranial aneurysms (IAs) represent protrusions in the vascular wall, with their growth and wall thinning influenced by various factors. These processes can culminate in the rupture of the aneurysm, leading to subarachnoid hemorrhage (SAH). Unfortunately, over half of the patients prove unable to withstand SAH, succumbing to adverse outcomes despite intensive therapeutic interventions, even in premier medical facilities. This study seeks to discern the pivotal microRNAs (miRNAs) and genes associated with the formation and progression of IAs.

Methods

The investigation gathered expression data of miRNAs (from GSE66240) and mRNAs (from GSE158558) within human aneurysm tissue and superficial temporal artery (STA) samples, categorizing them into IA and normal groups. This classification was based on the Gene Expression Omnibus (GEO) database.

Results

A total of 70 differentially expressed microRNAs (DEMs) and 815 differentially expressed mRNAs (DEGs) were pinpointed concerning IA. Subsequently, a miRNA-mRNA network was constructed, incorporating 9 significantly upregulated DEMs and 211 significantly downregulated DEGs. Simultaneously, functional enrichment and pathway analyses were conducted on both DEMs and DEGs. Through protein-protein interaction (PPI) network analysis and functional enrichment, 9 significantly upregulated DEMs (hsa-miR-188-5p, hsa-miR-590-5p, hsa-miR-320b, hsa-miR-423-5p, hsa-miR-140-5p, hsa-miR-486-5p, hsa-miR-320a, hsa-miR-342-3p, and hsa-miR-532-5p) and 50 key genes (such as ATP6V1G1, KBTBD6, VIM, PA2G4, DYNLL1, METTL21A, MDH2, etc.) were identified, suggesting their potential significant role in IA. Among these genes, ten were notably negatively regulated by at least two key miRNAs.

Conclusions

The findings of this study provide valuable insights into the potential pathogenic mechanisms underlying IA by elucidating a miRNA-mRNA network. This comprehensive approach sheds light on the intricate interplay between miRNAs and genes, offering a deeper understanding of the molecular dynamics involved in IA development and progression.

Factors affecting resolution of oculomotor nerve palsy following endovascular embolization of posterior communicating artery aneurysms

PURPOSE

To investigate the effect of endovascular embolization of posterior communicating artery (Pcom) aneurysms on concomitant oculomotor nerve palsy (OMNP) and factors affecting the effect of treatment.

MATERIALS AND METHODS

Patients with the Pcom aneurysms concomitant with OMNP were retrospectively enrolled for endovascular treatment of the aneurysms. All patients had the endovascular management. The clinical effect, degree of OMNP, size of the aneurysm, type of treatment, subarachnoid hemorrhage (SAH), and time from onset to treatment were analyzed on the resolution of OMNP.

RESULTS

Ninety-six patients with 99 Pcom aneurysms were enrolled and treated endovascularly, with the success rate of 100%. Immediately after endovascular treatment, 75 aneurysms (75.75%) got complete occlusion, and 24 (24.24%) nearly complete occlusion. Followed up for 3-18 (mean 8.52±0.56) months, complete resolution of the OMNP was achieved in 63 patients (65.63%), partial resolution in 21 (21.88%), and non-recovery in the other 12 (12.50%). The degree of OMNP at onset, SAH, and time from onset to treatment were significantly (P<0.05) correlated with the resolution of OMNP. Univariate analysis revealed that younger age of the patient, degree of OMNP at onset, presence of subarachnoid hemorrhage, and time from disease onset to treatment were significantly (P<0.05) associated with the recovery of OMNP. Multivariate analysis revealed that the younger age, degree of OMNP at onset, and time from disease onset to treatment were significantly (P<0.05) associated with the recovery of OMNP.

CONCLUSION

Endovascular embolization of Pcom aneurysms concomitant with OMNP can effectively improve the OMNP symptoms, especially for patients with moderate and a shorter history of OMNP. Younger age, degree of oculomotor nerve palsy at onset, and time from onset to treatment may significantly affect recovery of oculomotor nerve palsy.

Nomogram-based geometric and hemodynamic parameters for predicting the growth of small untreated intracranial aneurysms

Previous studies have shown that the growth status of intracranial aneurysms (IAs) predisposes to rupture. This study aimed to construct a nomogram for predicting the growth of small IAs based on geometric and hemodynamic parameters. We retrospectively collected the baseline and follow-up angiographic images (CTA/ MRA) of 96 small untreated saccular IAs, created patient-specific vascular models and performed computational fluid dynamics (CFD) simulations. Geometric and hemodynamic parameters were calculated. A stepwise Cox proportional hazards regression analysis was employed to construct a nomogram. IAs were stratified into low-, intermediate-, and high-risk groups based on the total points from the nomogram. Receiver operating characteristic (ROC) analysis, calibration curves, decision curve analysis (DCA) and Kaplan-Meier curves were evaluated for internal validation. In total, 30 untreated saccular IAs were grown (31.3%; 95%CI 21.8%-40.7%). The PHASES, ELAPSS, and UIATS performed poorly in distinguishing growth status. Hypertension (hazard ratio [HR] 4.26, 95%CI 1.61-11.28; P = 0.004), nonsphericity index (95%CI 4.10-25.26; P = 0.003), max relative residence time (HR 1.01, 95%CI 1.00-1.01; P = 0.032) were independently related to the growth status. A nomogram was constructed with the above predictors and achieved a satisfactory prediction in the validation cohort. The log-rank test showed significant discrimination among the Kaplan-Meier curves of different risk groups in the training and validation cohorts. A nomogram consisting of geometric and hemodynamic parameters presented an accurate prediction for the growth status of small IAs and achieved risk stratification. It showed higher predictive efficacy than the assessment tools.

Intracranial aneurysm detection: an object detection perspective

PURPOSE

Intracranial aneurysm detection from 3D Time-Of-Flight Magnetic Resonance Angiography images is a problem of increasing clinical importance. Recently, a streak of methods have shown promising performance by using segmentation neural networks. However, these methods may be less relevant in a clinical settings where diagnostic decisions rely on detecting objects rather than their segmentation.

METHODS

We introduce a 3D single-stage object detection method tailored for small object detection such as aneurysms. Our anchor-free method incorporates fast data annotation, adapted data sampling and generation to address class imbalance problem, and spherical representations for improved detection.

RESULTS

A comprehensive evaluation was conducted, comparing our method with the state-of-the-art SCPM-Net, nnDetection and nnUNet baselines, using two datasets comprising 402 subjects. The evaluation used adapted object detection metrics. Our method exhibited comparable or superior performance, with an average precision of 78.96%, sensitivity of 86.78%, and 0.53 false positives per case.

CONCLUSION

Our method significantly reduces the detection complexity compared to existing methods and highlights the advantages of object detection over segmentation-based approaches for aneurysm detection. It also holds potential for application to other small object detection problems.

Aspirin treatment for unruptured intracranial aneurysms: Focusing on its anti-inflammatory role

Intracranial aneurysms (IAs), as a common cerebrovascular disease, claims a worldwide morbidity rate of 3.2%. Inflammation, pivotal in the pathogenesis of IAs, influences their formation, growth, and rupture. This review investigates aspirin's modulation of inflammatory pathways within this context. With IAs carrying significant morbidity and mortality upon IAs rupture and current interventions limited to surgical clipping and endovascular coiling, the quest for pharmacological options is imperative. Aspirin's role in cardiovascular prevention, due to its anti-inflammatory effects, presents a potential therapeutic avenue for IAs. In this review, we examine aspirin's efficacy in experimental models and clinical settings, highlighting its impact on the progression and rupture risks of unruptured IAs. The underlying mechanisms of aspirin's impact on IAs are explored, with its ability examined to attenuate endothelial dysfunction and vascular injury. This review may provide a theoretical basis for the use of aspirin, suggesting a promising strategy for IAs management. However, the optimal dosing, safety, and long-term efficacy remain to be established. The implications of aspirin therapy are significant in light of current surgical and endovascular treatments. Further research is encouraged to refine aspirin's clinical application in the management of unruptured IAs, with the ultimate aim of reducing the incidence of aneurysms rupture.

Increased serum levels of high-mobility group box 1 protein and the location characteristics in the patients of intracranial aneurysms

OBJECTIVE

Inflammation-related factors play a crucial role in intracranial aneurysms (IA) initiation, progression, and rupture. High mobility group box 1 (HMGB-1) serves as an alarm to drive the pathogenesis of the inflammatory disease. This study aimed to evaluate the role of HMGB-1 in IA and explore the correlation with other inflammatory-related factors.

METHODS

A total of twenty-eight adult male Japanese white rabbits were included in with elastase-induced aneurysms, n = 18) and the control group (normal rabbits, n = 10). To assess the expression of HMGB-1, both reverse transcription-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA) was performed on serum samples obtained from human subjects (10 patients with IA and 10 healthy donors) as well as from rabbits (aneurysm group and control group). Immunohistochemistry and immunofluorescence were employed to evaluate the expression levels of elastic fibers, HMGB-1, tumor necrosis factor-alpha (TNF-α), and triggering receptor expressed on myeloid cells-1 (TREM-1).

RESULTS

The expression of HMGB-1 was found to be significantly higher in the IA group compared to the control group, both at the mRNA and protein levels (P < 0.0001). Similar findings were observed in the rabbit aneurysm model group compared to the control group (P < 0.0001). HMGB-1 expression was observed to be more abundant in the inner wall of the aneurysm compared to the external wall, whereas in the control group, it was rarely scattered. Additionally, the localization patterns of TNF-α and TREM-1 exhibited similar characteristics to HMGB-1.

CONCLUSION

Our findings demonstrate that HMGB-1 is highly expressed in both IA patients and rabbit aneurysm models. Furthermore, the similar localization patterns of HMGB-1, TNF-α, and TREM-1 suggest their potential involvement in the inflammatory processes associated with IA. These results highlight the potential of HMGB-1 as a novel therapeutic target for IA.

Appraising the causal association among depression, anxiety and intracranial aneurysms: Evidence from genetic studies

BACKGROUND

The risk of intracranial aneurysms (IAs) is increased in individuals with depression and anxiety. This indicates that depression and anxiety may contribute to the development of physical disorders. Herein, to investigate the association between genetic variants related to depression and anxiety and the risk of IA, two-sample Mendelian randomization was performed.

METHODS

The genome-wide association study (GWAS) comprised genome-wide genotype data of 2248 clinically well-characterized patients with anxiety and 7992 ethnically matched controls from four European countries. Sex-specific summary-level outcome data were obtained from the GWAS of IA, including 23 cohorts with a total of 10,754 cases and 306,882 controls of European and East Asian ancestry. To improve validity, five varying Mendelian randomization techniques were used in the analysis, namely Mendelian randomization-Egger, weighted median, inverse variance weighted, simple mode, and weighted mode.

RESULTS

The inverse variance weighted results indicated the causal effect of depression on IA (P = 0.03, OR = 1.32 [95 % CI, 1.03-1.70]) and unruptured IA (UIA) (P = 0.02, OR = 1.68 [95 % CI, 1.08-2.61]). However, the causal relationship between depression and subarachnoid hemorrhage (SAH) was not found (P = 0.16). We identified 43 anxiety-associated single-nucleotide polymorphisms as genetic instruments and found no causal relationship between anxiety and IA, UIA, and SAH.

LIMITATIONS

Potential pleiotropy, possible weak instruments, and low statistical power limited our findings.

CONCLUSION

Our MR study suggested a possible causal effect of depression on the increased risk of UIAs. Future research is required to investigate whether rational intervention in depression treatment can help to decrease the societal burden of IAs.

Evaluation of PHASES Score for Predicting Rupture of Intracranial Aneurysms: Significance of Aneurysm Size

BACKGROUND

Recent data have identified that certain risk factors for rupture differ between small and larger intracranial aneurysms (IAs). Such differing risk factors make up 5 out of the 6 predictor variables used in the PHASES score, which raises the question on whether IA size has a significant effect on the score's performance.

METHODS

Patients who were diagnosed with an IA incidentally or due to a subarachnoid hemorrhage between 2015 and 2023 were selected for potential inclusion. The median IA size of the cohort was chosen as the cutoff point to categorize small and large (6 mm). The PHASES score was calculated for all patients, and a receiver operating characteristic curve analysis was performed to evaluate the classification accuracy of PHASES in predicting rupture for small and large IAs.

RESULTS

A total of 677 IAs were included. Among the IAs, 400 (58.9%) presented as UIAs and 279 (41.0%) as subarachnoid hemorrhage. The average PHASES score was 2.9 and 6.5 for small (n = 322) and large (n = 355) IAs, respectively. The PHASES score performed significantly lower for predicting rupture in smaller IAs (area under the curve: 0.634) compared with the larger (area under the curve: 0.741) (P = 0.00083).

CONCLUSIONS

PHASES was shown to underperform on small IAs. The decision to treat small unruptured IAs remains highly controversial, and the development of a new score to estimate the annual rupture rate while accounting for IA morphology is of great need. Our findings can help encourage future researchers to develop such a score.

Serum Interleukin-1 Levels Are Associated with Intracranial Aneurysm Instability

Serum interleukin-1 (IL-1) are possibly indicative of the inflammation in the intracranial aneurysm (IA) wall. This study aimed to investigate whether IL-1 could discriminate the unstable IAs (ruptured intracranial aneurysms (RIAs) and symptomatic unruptured intracranial aneurysms (UIAs)) from stable, asymptomatic UIAs. IA tissues and blood samples from 35 RIA patients and 35 UIA patients were collected between January 2017 and June 2020 as the derivation cohort. Blood samples from 211 patients with UIAs were collected between January 2021 and June 2022 as the validation cohort (including 63 symptomatic UIAs). Blood samples from 35 non-cerebral-edema meningioma patients (non-inflammatory control) and 19 patients with unknown-cause subarachnoid hemorrhage (hemorrhagic control) were also collected. IL-1β and IL-1.ra (IL-1 receptor antagonist) were measured in serum and IA tissues, and the IL-1 ratio was calculated as log10 (IL-1.ra/IL-1β). Based on the derivation cohort, multivariate logistic analysis showed that IL-1β (odds ratio, 1.48, P = 0.001) and IL-1.ra (odds ratio, 0.74, P = 0.005) were associated with RIAs. The IL-1 ratio showed an excellent diagnostic accuracy for RIAs (c-statistic, 0.91). Histological analysis confirmed the significant correlation of IL-1 between serum and aneurysm tissues. IL-1 ratio could discriminate UIAs from non-inflammatory controls (c-statistic, 0.84), and RIAs from hemorrhagic controls (c-statistic, 0.95). Based on the validation cohort, the combination of IL-1 ratio and PHASES score had better diagnostic accuracy for symptomatic UIAs than PHASES score alone (c-statistic, 0.88 vs 0.80, P < 0.001). Serum IL-1 levels correlate with aneurysm tissue IL-1 levels and unstable aneurysm status, and could serve as a potential biomarker for IA instability.

Traumatic Falcine Artery Aneurysm Resulting in Intracranial Hemorrhage

A 50-year-old man presented with mild unconsciousness after a fall-induced head injury. Initial imaging revealed a left-sided acute subdural hematoma. After transportation to our hospital, his condition deteriorated, leading to the discovery of a new hemorrhage and an anterior falcine artery aneurysm upon further examination. The patient underwent successful decompressive craniectomy and endovascular occlusion. This case, the first reported of a traumatic anterior falcine artery aneurysm, suggests the initial injury caused both the hematoma and aneurysm. The aneurysm's specific location near the crista galli likely contributed to the formation of the traumatic aneurysm, and the compression of the left frontal lobe by the acute subdural hematoma caused the subsequent hemorrhage. This case highlights the importance of considering traumatic aneurysms in atypical postinjury hemorrhages and adds to the understanding of traumatic intracranial aneurysms' mechanisms.

Efficacy and Safety of Extracranial-Intracranial Bypass Surgery for Posterior Circulation Aneurysms: A Systematic Review and Single-Arm Meta-Analysis

OBJECTIVE

Treating complex posterior circulation aneurysms poses challenges, and extracranial to intracranial (EC-IC) bypass techniques are potential therapeutic options. However, the safety and efficacy of this approach for posterior circulation aneurysms remain unclear. The study's objective was to assess the safety and efficacy of EC-IC bypass in these aneurysms.

METHODS

Adhering to Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines, we conducted a systematic review on EC-IC revascularization for posterior circulation aneurysms. Included studies had at least 4 patients and reported data on mortality, patency, complications, or clinical outcomes. Favorable clinical outcomes were defined as modified Rankin Scale below 3 or Glasgow Outcome Scale above 3, and complications were any issues related to the bypass procedure.

RESULTS

From 3036 articles reviewed, 22 studies involving 196 patients who underwent 210 EC-IC bypass procedures for posterior circulation aneurysms were selected. The median follow-up period of 14 studies was 31.66 months (6-61 months). Final follow-up indicated a high bypass patency rate of 96% [95% confidence interval [CI]: 91%-100%; I2 = 12%], with a mortality rate of 5% [95% CI: 1%-9%; I2 = 0%]. Additionally, 83% [95% CI: 70%-96%; I2 = 77%] of patients showed good outcomes at the last follow-up. Complications were observed in 40% [95% CI: 26%-55%; I2 = 80%]. Heterogeneity was associated with specific studies.

CONCLUSIONS

EC-IC bypass procedures are a viable treatment option for posterior circulation aneurysms, with high bypass patency rates and favorable clinical outcomes. However, complications, especially neurological deficits, exist. Open revascularization remains essential for neurovascular surgeons dealing with complex aneurysms.

Flow diverter stenting for intracranial aneurysms in the pediatric population: Two case reports and literature review

The Pipeline Embolization Device (PED) is a flow-diverting intraluminal device that is approved for use in adults 18 years or older with internal carotid artery aneurysms. However, it can also be used off-label in pediatric patients with aneurysms that cannot be resolved with traditional endovascular treatments. Herein, we present two cases of flow diversion in the pediatric population with complete obliteration of the aneurysm and excellent outcomes. Flow diversion has been shown to be a safe endovascular option in treating complex aneurysms in children. Larger-sized, multicenter trials are encouraged to compare outcomes between flow diversion and other aneurysm treatment options given the rarity of pediatric aneurysms.

Circular RNAs in intracranial aneurysms: Emerging roles in pathogenesis, diagnosis and therapeutic intervention

Intracranial aneurysms (IAs) present a substantial health threat, given the potential for catastrophic ruptures and subarachnoid hemorrhages (SAH). Swift and effective measures for diagnosis and treatment are paramount to enhance patient outcomes and alleviate the associated healthcare burden. In this context, circular RNAs (circRNAs) have emerged as an intriguing area of investigation, offering promise as both diagnostic biomarkers and therapeutic targets for IAs. CircRNAs have demonstrated their influence on critical molecular and cellular processes underpinning IAs pathogenesis, revealing their pivotal role in understanding this complex ailment. Beyond their diagnostic potential, circRNAs hold great potential as prognostic markers, providing crucial insights into IAs rupture risk. The unique circular structure and their regulatory functions make circRNAs an enticing avenue for innovative therapeutic approaches. The ongoing study of circRNAs in the context of IAs is an exciting and rapidly evolving field that has the potential to revolutionize approaches to diagnosis, treatment, and prevention of this life-threatening condition. As research continues to unravel the intricate roles of circRNAs, they are poised to become invaluable tools in clinical practice, enhancing patient care and ultimately reducing the impact of cerebral aneurysms on both individuals and healthcare systems. This comprehensive review delves deeply into the world of circRNAs in the realm of IAs, elucidating their multifaceted roles in the onset and progression of this condition. Moreover, this review ventures into the diagnosis and therapeutic potential of circRNAs, exploring their possible applications in gene therapy and as targets for novel treatment modalities.

Constrained estimation of intracranial aneurysm surface deformation using 4D-CTA

BACKGROUND AND OBJECTIVE

Intracranial aneurysms are relatively common life-threatening diseases, and assessing aneurysm rupture risk and identifying the associated risk factors is essential. Parameters such as the Oscillatory Shear Index, Pressure Loss Coefficient, and Wall Shear Stress are reliable indicators of intracranial aneurysm development and rupture risk, but aneurysm surface irregular pulsation has also received attention in aneurysm rupture risk assessment.

METHODS

The present paper proposed a new approach to estimate aneurysm surface deformation. This method transforms the estimation of aneurysm surface deformation into a constrained optimization problem, which minimizes the error between the displacement estimated by the model and the sparse data point displacements from the four-dimensional CT angiography (4D-CTA) imaging data.

RESULTS

The effect of the number of sparse data points on the results has been discussed in both simulation and experimental results, and it shows that the proposed method can accurately estimate the surface deformation of intracranial aneurysms when using sufficient sparse data points.

CONCLUSIONS

Due to a potential association between aneurysm rupture and surface irregular pulsation, the estimation of aneurysm surface deformation is needed. This paper proposed a method based on 4D-CTA imaging data, offering a novel solution for the estimation of intracranial aneurysm surface deformation.

Ongoing Geometric Remodeling of the Parent Artery After Flow-Diverter Stent Reconstruction in Cerebral Aneurysms: The Device Design Matters

OBJECTIVE

Configuration changes of the parent artery (PA) after flow-diverter (FD) stent reconstruction, caused by the bending force of the device, may have an additional role in aneurysm occlusion as a result of the secondary alteration of intra-aneurysmal hemodynamics related to the geometry alteration of the vessel. To determine the degree of PA deformation and aneurysm occlusion rates after deployment of 2 different types of FD.

METHODS

Patients treated with 2 different designs of cobalt-chromium braid (48 and 64 wire braid) structure FD were subject to analysis. Vascular angle changes at the level of the reconstructed segment immediately after FD deployment and at 1 year follow-up were measured and the potential relationship with aneurysmal occlusion rate was analyzed.

RESULTS

Forty-two patients harboring 48 aneurysms were included in the present study. The aneurysms were divided into side wall (85.4%) and bifurcation types (14.6%). Twenty-six aneurysms were treated using the Pipeline FD (48 wire braid; 54.2%) and 22 using the Evolve FD (64 wire braid; 45.8%). Of the 48 aneurysms, 42 (87.5%) met the primary end point of complete occlusion at 12 months. The median postdeployment angle change was 7.04°± 4.59° for the Pipeline and 5.05°± 2.49° for the Evolve, whereas the median 12 months follow-up angle change was 15.49°± 10.99° and 10.01°± 8.83°, respectively. PA angle changes were significantly higher in the bifurcation group compared with the side wall group both during procedure and at 12 months follow-up. Angle change had a statistically nonsignificant association with complete aneurysm occlusion.

CONCLUSIONS

PA deformation starts immediately after deployment and remodeling continues for 1 year after. Aneurysms located in the vessel bifurcation were more prone to PA straightening after FD deployment than were side wall aneurysms. Furthermore, Pipeline seemed to be more prone to inducing vascular deformation, compared with Evolve.

Predictors for Rupture of Small (<7mm) Intracranial Aneurysms: A Systematic Review and Meta-Analysis

INTRODUCTION

Identifying predictors for rupture of small intracranial aneurysms (sIAs) have become a growing topic in the literature given the relative paucity of data on their natural history. The authors performed a meta-analysis to identify reliable predictors.

METHODS

PubMed, Scopus, and Web of Science were used to systematically extract references which involved at least 10 IAs <7mm which including a control group experiencing no rupture. All potential predictors reported in the literature were evaluated in the meta-analysis.

RESULTS

Fifteen studies yielding 4,739 sIAs were included in the meta-analysis. Four studies were prospective and 11 were retrospective. Univariate analysis identified 7 predictors which contradicted or are absent in the current scoring systems, while allowing to perform subgroup analysis for further reliability: patient age (MD -1.97, 95%CI -3.47-0.48; P = 0.01), the size ratio (MD 0.40, 95%CI 0.26-0.53; P < 0.00001), the aspect ratio (MD 0.16, 95%CI 0.11-0.22; P < 0.00001), bifurcation point (OR 3.76, 95%CI 2.41-5.85; P < 0.00001), irregularity (OR 2.95, 95%CI 1.91-4.55; P < 0.00001), the pressure loss coefficient (MD -0.32, 95%CI -0.52-0.11; P = 0.002), wall sheer stress (Pa) (MD -0.16, 95%CI -0.28-0.03; P = 0.01). All morphology related predictors listed above have been confirmed as independent predictors via multivariable analysis among the individual studies.

CONCLUSIONS

Morphology related predictors are superior to the classic patient demographic predictors present in most scoring systems. Given that morphology predictors take time to measure, our findings may be of great interest to developers seeking to incorporate artificial intelligence into the treatment decision-making process.

Hemodynamic alterations of flow diverters on aneurysms at the fetal posterior communicating artery: A simulation study using CFD to compare the surpass streamline, pipeline flex, and tubridge devices

PURPOSE

Traditional flow diverters (FDs) for treating aneurysms at the fetal posterior communicating artery are unsatisfactory. Surpass Streamline is a novel FD with different mesh characteristics; however, the outcomes for such aneurysms remain unclear. This study aimed to compare hemodynamic alterations induced by Surpass Streamline, Pipeline Flex, and Tubridge devices and explore possible strategies for aneurysms at the fetal posterior communicating artery.

METHODS

Two simulated aneurysms (Case 1, Case 2) were constructed from digital subtraction angiography (DSA). The three FDs were virtually deployed, and hemodynamic analysis based on computational fluid dynamics was performed. Hemodynamic parameters, including the sac-averaged velocity magnitude (Velocity), high-flow volume (HFV), and wall shear stress (WSS), were compared between each FD and the untreated model (control). Surpass Streamline was performed in real life for two aneurysms and the clinical outcomes were collected for analysis.

RESULTS

Compared to the control, the Surpass resulted in the most significant reduction in flow. In Case 1, the Velocity, HFV, and WSS were reduced by 51.6%, 78.1%, and 64.3%, respectively. In Case 2, the Velocity, HFV, and WSS were reduced by 48.0%, 81.1%, and 65.3%, respectively. Tubridge showed slightly larger changes in hemodynamic parameters than Pipeline. In addition, our analysis suggested that metal coverage was correlated with the WSS, Velocity, and HFV. The postoperative DSA showed that the aneurysm was nearly occluded in Case 1 and decreased in Case 2.

CONCLUSION

Compared to that with the Pipeline and Tubridge, the Surpass resulted in the greatest reduction in hemodynamic parameters and might be effective for aneurysms at the fetal posterior communicating artery. Virtual FD deployment and computational fluid dynamics analysis may be used to predict the treatment outcomes.

Exploring the Landscape of Intracranial Aneurysms in South America: A Comprehensive Narrative Review Intracranial Aneurysms in South America

Exploring the landscape of intracranial aneurysms in South America unravels a complex interplay of epidemiological factors, clinical manifestations, and therapeutic challenges. The study methodically conducts a comprehensive literature review spanning the years 2003 to 2023, focusing on English-language articles obtained from diverse databases to elucidate the multifaceted nature of intracranial aneurysms in the region. Results and discussions categorize outcomes into positive domains, emphasizing successful treatments, favorable recoveries, and high survival rates, while also shedding light on negative aspects such as residual aneurysms and complications. The research illuminates significant gaps in pathological typing of intracranial aneurysms and exposes challenges in healthcare accessibility, notably the disparities in neurosurgical resources. Management challenges, including constrained infrastructure access, a neurosurgeon shortage, and gender disparities, are underscored. Transitioning to future prospects, the study advocates for strategic interventions, proposing expanded neurosurgical training, multidisciplinary approaches, improved funding, enhanced access to care, and fostering international collaborations. The study concludes by emphasizing the pivotal role of collaborative efforts, intensified training programs, and global partnerships in propelling intracranial aneurysm management forward in South America, ultimately contributing to enhanced patient outcomes across the region.

Image-based hemodynamic simulations for intracranial aneurysms: the impact of complex vasculature

PURPOSE

Hemodynamics play an important role in the assessment of intracranial aneurysm (IA) development and rupture risk. The purpose of this study was to examine the impact of complex vasculatures onto the intra-vessel and intra-aneurysmal blood flow.

METHODS

Complex segmentation of a subject-specific, 60-outlet and 3-inlet circle of Willis model captured with 7T magnetic resonance imaging was performed. This model was trimmed to a 10-outlet model version. Two patient-specific IAs were added onto both models yielding two pathological versions, and image-based blood flow simulations of the four resulting cases were carried out. To capture the differences between complex and trimmed model, time-averaged and centerline velocities were compared. The assessment of intra-saccular blood flow within the IAs involved the evaluation of wall shear stresses (WSS) at the IA wall and neck inflow rates (NIR).

RESULTS

Lower flow values are observed in the majority of the complex model. However, at specific locations (left middle cerebral artery 0.5 m/s, left posterior cerebral artery 0.25 m/s), higher flow rates were visible when compared to the trimmed counterpart. Furthermore, at the centerlines the total velocity values reveal differences up to 0.15 m/s. In the IAs, the reduction in the neck inflow rate and WSS in the complex model was observed for the first IA (IA-A δNIRmean =  - 0.07ml/s, PCA.l δWSSmean =  - 0.05 Pa). The second IA featured an increase in the neck inflow rate and WSS (IA-B δNIRmean = 0.04 ml/s, PCA.l δWSSmean = 0.07 Pa).

CONCLUSION

Both the magnitude and shape of the flow distribution vary depending on the model's complexity. The magnitude is primarily influenced by the global vessel model, while the shape is determined by the local structure. Furthermore, intra-aneurysmal flow strongly depends on the location in the vessel tree, emphasizing the need for complex model geometries for realistic hemodynamic assessment and rupture risk analysis.

Stent-assistant versus non-stent-assistant coiling for ruptured and unruptured intracranial aneurysms: A meta-analysis and systematic review

Background

Several different endovascular and non-invasive treatment methods are suggested for the various types of intracranial aneurysms including simple, balloon-assisted, and stent-assisted coiling (SAC). Previous studies investigated the safety and efficacy of SAC versus non-stent-assisted coiling (non-SAC) but the results were controversial. We aim to perform a systematic review and meta-analysis to compare the efficacy and safety of SAC with non-SAC technique in stratifying by the ruptured and unruptured aneurysms.

Methods

PubMed, Scopus, Web of Science, and Cochrane Central Register of Controlled Trials were searched in April 2022 for studies investigated the efficacy and safety of SAC versus non-SAC.

Results

Overall, 26 studies entered into our qualitative and quantitative synthesis. We found that there was overall lower recurrence rate in SAC versus non-SAC significant (RR: 0.43, 95%CI: 0.33, 0.53). Furthermore, the comparisons were significant in unruptured (RR: 0.63, 95%CI: 0.40, 0.86), ruptured (RR: 0.29, 95%CI), and combination aneurysms (RR: 0.42, 95%CI: 0.30, 0.54). Also, we found higher risk of intraprocedural rupture for SAC versus non-SAC in unruptured aneurysms (RR: 1.40, 95%CI: 1.31, 1.50). Investigating hemorrhagic events risk showed that there was significant difference in ruptured (RR: 1.73, 95%CI: 1.12, 2.34) and combination aneurysms (RR: 0.60, 95%CI: 0.37, 0.82). There was no significant difference in immediate occlusion rate, complete occlusion, and risk of ischemic events in our analysis.

Conclusion

Overall, our findings demonstrated that SAC may have higher efficacy in term of recurrence rate, but also may have a higher risk of complications in the treatment of intracranial aneurysms. As there are several factors affecting the outcomes and safety of these interventions, further RCTs controlled for multiple factors are required better guide the neurointerventionists choose the best strategy.

Clipping of Anterior Circulation Aneurysms: Operative Instructions and Safety Rules for Young Cerebrovascular Surgeons

INTRODUCTION

Due to the constant development of the technique, in the last 30 years, the endovascular treatment of the intracranial aneurysms (IAs) has gradually superseded the traditional surgery in the majority of centers. However, clipping still represents the best treatment for some anterior circulation IAs according to their angioarchitectural, topographical, and hemodynamic characteristics. Thus, the identification of residual indications for clipping and the maintenance of training programs in vascular neurosurgery appear nowadays more important than ever.

MATERIALS AND METHODS

We reviewed our last 10-year institutional experience of ruptured and unruptured IAs clipping. We appraised in detail all technical refinements we adopted during this time span and analyzed the difficulties we met in teaching the aneurysm clipping technique to residents and fellows. Then, we described the algorithm of safety rules we used to teach young neurosurgeons how to surgical approach anterior circulation IAs and develop a procedural memory, which may intervene in all emergency situations.

RESULTS

We identified seven pragmatic technical key points for clipping of the most frequent anterior circulation IAs and constructed a didactic approach to teach young cerebrovascular surgeons. In general, they concern craniotomy; cisternostomy; obtaining proximal control; cranial nerve, perforator, and vein preservation; necessity of specific corticectomy; aneurysm neck dissection; and clipping.

CONCLUSION

In the setting of an IA clipping, particularly when ruptured, the young cerebrovascular surgeon needs to respect an algorithm of safety rules, which are essential not only to avoid major complications, but they may intervene during the difficulties helping to manage potentially life-tethering conditions.

Fusiform aneurysms of anterior cerebral artery: center experience and systematic literature review

Fusiform aneurysms of the anterior cerebral artery (ACA) are uncommon, and the natural history of this entity is poorly characterized. Along with our center experience, we conducted a systematic literature review to help shed light on the clinical course of ACA fusiform aneurysms. We queried our institutional database to identify cases with fusiform aneurysms of ACA. In addition, following the PRISMA algorithm, we identified all reported cases published in the English literature from the inception of PubMed until December 2022. We categorized clinical presentations into three categories: (i) traumatic/iatrogenic, (ii) spontaneous symptomatic ruptured/unruptured, and (iii) spontaneous asymptomatic aneurysms. We utilized descriptive statistics. We identified seven cases from our center along with 235 patients from published literature. Blunt trauma was responsible for the development of 19 aneurysms. Sixty-three percent of these aneurysms tend to rupture within 2 weeks from the initial trauma, and despite treatment, only 74% of these patients had good clinical outcomes. Spontaneous symptomatic presentation occurred in 207 patients and was often associated with previous/concomitant ACA dissection. Subarachnoid hemorrhage from ruptured aneurysms was the most common presentation. Spontaneous symptomatic fusiform aneurysm is rapidly evolving lesions, and treatment is necessary. Three of our own cases were treated with an endovascular flow diverter (pipeline) stenting with good outcomes. Spontaneous asymptomatic aneurysms were reported in nine patients. These lesions are often associated with other vascular abnormalities. Treatment included surgical clipping with good clinical outcomes. Instead, four patients from our center database were managed conservatively with equally good outcomes. Our study demonstrates good clinical outcomes when fusiform aneurysms of ACA, especially when symptomatic, are treated promptly with either reconstructive or deconstructive therapies.

Activation of BMP4-pSmad1/5 pathway impairs the function of VSMCs in intracranial aneurysms

Intracranial aneurysms (IAs) are characterized by abnormal dilatation of the cerebral vessels. Vascular smooth muscle cells (VSMCs) are implicated in maintaining vascular homeostasis. Disordered VSMCs are one of the most common causes for occurrence and development of IAs. The bone morphogenetic protein 4 (BMP4) signalling pathway is involved in regulating cell proliferation, apoptosis, and differentiation. This study aimed to investigate the effects of BMP4 on VSMCs and its underlying mechanisms. BMP4 was upregulated in the VSMCs of IAs and caused apoptosis of VSMCs through Smad1/5 phosphorylation. In addition, BMP4 overexpression significantly promoted the proliferation and migration of VSMCs and induced a phenotypic transformation from contractile to inflammatory. Our findings facilitate further understanding of the occurrence and development of IAs and provide a potential therapeutic target.

Occipital artery-to-PICA bypass: how I do it

BACKGROUND

Posterior inferior cerebellar artery (PICA) aneurysms are uncommon, and their management is challenging because of the complex angioarchitecture of the PICA and the frequently nonsaccular aneurysm presentation. Endovascular therapy may not be feasible.

METHODS

We describe our technique of clip trapping with occipital artery (OA)-to-PICA bypass to treat a PICA aneurysm. Because the aneurysm affected the ipsilateral, dominant PICA, an OA-PICA bypass was chosen to ensure adequate flow and reduce risk to the contralateral PICA supply.

CONCLUSION

The OA-PICA anastomosis is a safe and effective method to successfully achieve flow preservation with bypass reconstruction and aneurysm trapping.

Preoperative scale proposal based on clinical outcome for elderly patients with ruptured intracranial aneurysms undergoing microsurgery

INTRODUCTION

Life expectancy in individuals has increased in recent years. There is no consensus in the literature on the best treatment for a ruptured aneurysm in the elderly (> 60 years), but some places only have microsurgery as a therapeutic strategy. This work aims to develop a prognostic scale for ruptured intracranial aneurysms in the elderly.

MATERIAL AND METHODS

Two thousand five hundred thirty patients with subarachnoid hemorrhage were retrospectively evaluated in the last ten years, and 550 of them were elderly. We developed a prognostic scale from the analysis of medical records, clinical and tomographic features that had statistical significance. Glasgow Coma Outcome (GOS) was the outcome of interest and p value < 0,05 was considered statistically significant.

RESULTS

Five hundred fifty patients were evaluated, and the comorbidities that were independent variables for poor prognosis were smoking and arterial hypertension; clinical variables were Hunt-Hess, modified Rankin and Glasgow Coma Scale; tomographic was Fisher scale. Poor outcome was defined as GOS ≤ 3. Poor surgical outcomes were more remarkable in the high-risk factor categories, being 6.41 times higher among individuals who had 3 to 4 risk factors and 8.80 times higher among individuals with 5 to 6 risk factors.

CONCLUSION

In some vascular neurosurgery services worldwide, microsurgery is the only therapeutic option. This scale aimed at the elderly patient individualizes the treatment and can predict the clinical outcome in ruptured intracranial aneurysms.

Application of convolutional network models in detection of intracranial aneurysms: A systematic review and meta-analysis

INTRODUCTION

Intracranial aneurysms have a high prevalence in human population. It also has a heavy burden of disease and high mortality rate in the case of rupture. Convolutional neural network(CNN) is a type of deep learning architecture which has been proven powerful to detect intracranial aneurysms.

METHODS

Four databases were searched using artificial intelligence, intracranial aneurysms, and synonyms to find eligible studies. Articles which had applied CNN for detection of intracranial aneurisms were included in this review. Sensitivity and specificity of the models and human readers regarding modality, size, and location of aneurysms were sought to be extracted. Random model was the preferred model for analyses using CMA 2 to determine pooled sensitivity and specificity.

RESULTS

Overall, 20 studies were used in this review. Deep learning models could detect intracranial aneurysms with a sensitivity of 90/6% (CI: 87/2-93/2%) and specificity of 94/6% (CI: 0/914-0/966). CTA was the most sensitive modality (92.0%(CI:85/2-95/8%)). Overall sensitivity of the models for aneurysms more than 3 mm was above 98% (98%-100%) and 74.6 for aneurysms less than 3 mm. With the aid of AI, the clinicians' sensitivity increased to 12/8% and interrater agreement to 0/193.

CONCLUSION

CNN models had an acceptable sensitivity for detection of intracranial aneurysms, surpassing human readers in some fields. The logical approach for application of deep learning models would be its use as a highly capable assistant. In essence, deep learning models are a groundbreaking technology that can assist clinicians and allow them to diagnose intracranial aneurysms more accurately.

Treatment with a flow diverter-assisted coil embolization for ruptured blood blister-like aneurysms of the internal carotid artery: a technical note and analysis of single-center experience with pooled data

Treatment of blood blister-like aneurysms (BBAs) of the supraclinoid internal carotid artery (ICA) with flow diverters (FDs) has become widespread in recent years. However, ruptured blood blister-like aneurysm (BBA) of ICA treatment with flow diverter-assisted coil embolization (FDAC) remains controversial. Moreover, limited direct comparative studies have been conducted between the two treatment modalities, FDs and FDAC, for BBAs. The purpose of this study was to document our experience and evaluate the effectiveness and safety of FDAC. We conducted a retrospective analysis of clinical and radiological information from ten patients who experienced ruptured BBAs of the supraclinoid ICA at our center from January 2021 to February 2023. The technical details of FDAC for ruptured BBAs were described, and the technical steps were named "pipeline embolization device (PED)-Individualized shaping(microcatheter)-Semi deploying-Rivet(coils)-Massage(microwire)" as the PEISSERM technique. Clinical outcomes were assessed using the modified Rankin Scale (mRS), whereas radiological results were determined through angiography. A pooled analysis was implemented, incorporating data from literature sources that reported perioperative and long-term clinical and angiographic outcomes of ruptured BBAs treated with FD and FDAC strategies, along with our data. Data in our analysis pool were categorized into FD and FDAC strategy groups to explore the preferred treatment modalities for BBAs. The PEISSERM technique was utilized to treat ten patients, seven males, and three females, with an average age of 41.7 years. A single PED was deployed in conjunction with coils in all ten patients. All PEDs were documented to have good wall apposition. The immediate postoperative angiograms demonstrated Raymond grade I in ten aneurysms. Angiographic follow-up of nine patients at 4-25 months showed total occlusion of the aneurysms. At the most recent follow-up, the mRS scores of nine patients hinted at a good prognosis. Pooled analysis of 233 ICA-BBA cases of FD revealed a technical success rate of 91% [95% confidence interval (CI), 0.88 to 0.95], a rate of complete occlusion of 79% (95% CI, 0.73 to 0.84), a recurrence rate of 2% (95% CI, 0.00 to 0.04), a rebleed rate of 2% (95% CI, 0.00 to 0.04), and the perioperative stroke rate was 8% (95% CI, 0.04 to 0.11). The perioperative mortality was 4% (95% CI, 0.01 to 0.07). The long-term good clinical outcome rate was 85% (95% CI, 0.80 to 0.90). The mortality rate was 6% (95% CI, 0.03 to 0.09). Results from the subgroup analysis illustrated that the FDAC strategy for BBAs had a significantly higher immediate postoperative complete occlusion rate (P < 0.001), total occlusion rate (P = 0.016), and a good outcome rate (P = 0.041) compared with the FD strategy. The FDAC strategy can yield a higher rate of good outcomes than the FD strategy. The PEISSERM technique employed by the FDAC is a reliable and effective treatment approach as it can minimize the hemodynamic burden of BBA's fragile dome, thereby achieving an excellent occlusion rate. The PEISSERM technique in the FDAC strategy contributes to understanding the BBA's treatment and offers a potentially optimal treatment for BBA.

Cigarette Smoking and Intracranial Aneurysms: A Pilot Analysis of SNPs in the CYP2A6 Gene in the Italian Population

BACKGROUND

Cigarette smoking is a modifiable risk factor associated with formation and rupture of intracranial aneurysms (IAs). Cytochrome P450 2A6 (CYP2A6) is the main enzyme implied in catabolism of nicotine and xenobiotics, giving rise to oxidative stress products. Our study investigated the associations between specific single-nucleotide polymorphisms (SNPs) in the CYP2A6 gene and the presence of sporadic IAs in a cluster of Italian patients, as well as their rupture regarding cigarette smoking habit.

METHODS

Three hundred and thirty-one Italian patients with sporadic IAs were recruited in a single institution. We recorded data on clinical onset with subarachnoid hemorrhage (SAH) and smoking habit. Genetic analysis was performed with a standard procedure on peripheral blood samples: CYP2A6 ∗1B2, CYP2A6 ∗2, and CYP2A6 ∗14 SNPs were analyzed in the study group along with 150 healthy control subjects. Statistical analysis was conducted according to genetic association study guidelines.

RESULTS

In the patient cohort, the frequency of aSAH was significantly higher in current smokers (P < 0.001; OR=17.45), regardless of the pattern of CYP2A6 SNPs. There was a correlation between IA rupture and cigarette smoking in patients with the heterozygous CYP2A6 ∗1B2 allele (P < 0.001; OR=15.47). All patients carrying the heterozygous CYP2A6 ∗14 allele had an aSAH event (100%), regardless of smoking habit, although this correlation was not statistically significant (P = 1).

CONCLUSIONS

According to our findings, a cigarette smoker carrying a fully active CYP2A6 enzyme (heterozygous ∗1B2 allele) may have an increased risk of IA rupture compared to those with functionally less active variants: further investigation on a larger sample is needed to verify this result. The role of the heterozygous CYP2A6 ∗14 allele in aSAH is yet to be clarified.

Safety and efficacy of the pipeline embolization device for treatment of small vs. large aneurysms: a systematic review and meta-analysis

Flow diversion with the pipeline embolization device (PED) is increasingly used to treat intracranial aneurysms with high obliteration rates and low morbidity. However, long-term (≥ 1 year) angiographic and clinical outcomes still require further investigation. The aim of this study was to compare the occlusion and complication rates for small (< 10 mm) versus large (10-25 mm) aneurysms at long-term following treatment with PED. A systematic review and meta-analysis were performed in compliance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. We conducted a comprehensive search of English language databases including Ovid MEDLINE and Epub Ahead of Print, In-Process, and Daily, Ovid EMBASE, Ovid Cochrane Central Register of Controlled Trials, Ovid Cochrane Database of Systematic Reviews, and Scopus. Our studies included a minimum of 10 patients treated with PED for small vs. large aneurysms and with at least 12 months of follow-up. The primary safety endpoint was the rate of clinical complications measured by the occurrence of symptomatic stroke (confirmed clinically and radiographically), intracranial hemorrhage, or aneurysmal rupture. The primary efficacy endpoint was the complete aneurysm occlusion rate. Our analysis included 19 studies with 1277 patients and 1493 aneurysms. Of those, 1378 aneurysms met our inclusion criteria. The mean age was 53.9 years, and most aneurysms were small (89.75%; N = 1340) in women (79.1%; N = 1010). The long-term occlusion rate was 73% (95%, CI 65 to 80%) in small compared to 84% (95%, CI 76 to 90%) in large aneurysms (p < 0.01). The symptomatic thromboembolic complication rate was 5% (95%, CI 3 to 9%) in small compared to 7% (95%, CI 4 to 13%) in large aneurysms (p = 0.01). The rupture rate was 2% vs. 4% (p = 0.92), and the rate of intracranial hemorrhage was 2% vs. 4% (p = 0.96) for small vs. large aneurysms, respectively; however, these differences were not statistically significant. The long-term occlusion rate after PED treatment is higher in large vs. small aneurysms. Symptomatic thromboembolic rates with stroke are also higher in large vs. small aneurysms. The difference in the rates of aneurysm rupture and intracranial hemorrhage was insignificant. Although the PED seems a safe and effective treatment for small and large aneurysms, further studies are required to clarify how occlusion rate and morbidity are affected by aneurysm size.

Two consecutive ruptured intracranial aneurysm in patient with multiple intracranial aneurysms

When aneurysmal subarachnoid hemorrhage due to multiple aneurysms is suspected, identifying the rupture site is essential to determine the exact surgical site, but it may not be easy. Even if embolization is adequately performed, complications may remain. Typical complications include rebleeding and hydrocephalus in the early phase and delayed cerebral ischemia in the delayed phase. Herein, we describe a case of rupture of an intracranial aneurysm after performing embolization for a different ruptured intracranial aneurysm in a patient with multiple intracranial aneurysms. Patients with multiple intracranial aneurysms need to be considered for closer observation than those with a single ruptured intracranial aneurysm, even if the patient's prognosis is good.

A deep learning framework for intracranial aneurysms automatic segmentation and detection on magnetic resonance T1 images

OBJECTIVES

To design a deep learning-based framework for automatic segmentation and detection of intracranial aneurysms (IAs) on magnetic resonance T1 images and test the robustness and performance of framework.

METHODS

A retrospective diagnostic study was conducted based on 159 IAs from 136 patients who underwent the T1 images. Among them, 127 cases were randomly selected for training and validation, and 32 cases were used to assess the accuracy and consistency of our algorithm. We developed and assembled three convolutional neural networks for the segmentation and detection of IAs. The segmentation and detection performance of the model were compared with the ground truth, and various metrics were calculated at the voxel level, IAs level, and patient level to show the performance of our framework.

RESULTS

Our assembled model achieved overall Dice, voxel-level sensitivity, specificity, balanced accuracy, and F1 score of 0.802, 0.874, 0.9998, 0.937, and 0.802, respectively. A coincidence greater than 0.7 between the aneurysms predicted by the model and the ground truth was considered as a true positive. For IAs detection, the sensitivity reached 90.63% with 0.58 false positives per case. The volume of IAs segmented by our model showed a high agreement and consistency with the volume of IAs labeled by experts.

CONCLUSION

The deep learning framework is achievable and robust for IAs segmentation and detection. Our model offers more clinical application opportunities compared to digital subtraction angiography (DSA)-based, CTA-based, and MRA-based methods.

CLINICAL RELEVANCE STATEMENT

Our deep learning framework effectively detects and segments intracranial aneurysms using clinical routine T1 sequences, showing remarkable effectiveness and offering great potential for improving the detection of latent intracranial aneurysms and enabling early identification.

KEY POINTS

•There is no segmentation method based on clinical routine T1 images. Our study shows that the proper deep learning framework can effectively localize the intracranial aneurysms. •The T1-based segmentation and detection method is more universal than other angiography-based detection methods, which can potentially reduce missed diagnoses caused by the absence of angiography images. •The deep learning framework is robust and has the potential to be applied in a clinical setting.

Predictive Model Evaluating Risk of Hemorrhage in Intracranial Aneurysms: Analysis from Prospectively Collected HEAT Trial Database

OBJECTIVE

We analyzed the data of patients enrolled in the Hydrogel Endovascular Aneurysm Treatment (HEAT) trial to develop and validate a model to predict the risk of aneurysmal hemorrhage.

METHODS

Analysis included data from 600 patients enrolled for the HEAT trial and included single saccular aneurysms of 3-14 mm size. Baseline characteristics were compared between patients with ruptured and unruptured aneurysms. Regression analysis was performed in the training set to identify significant risk factors and was validated in the validation dataset. The complete dataset was used to formulate a scoring model in which positive and negative predictors were assigned 1 and -1 points, respectively.

RESULTS

Data from 593 patients were analyzed in which 169 (28.5%) patients had ruptured aneurysms. The training (n = 297) and validation dataset (n = 296) had a comparable proportion of ruptured aneurysms (29.3% and 27.7%). Dome-to-neck ratio >2.5 (odds ratio [OR] 3.66), irregular shape (OR 3.79), daughter sac (OR 5.89), and anterior and posterior communicating artery locations (OR 3.32 and 3.56, respectively) had a higher rupture rate. Use of aspirin was associated with lower risk of hemorrhage (OR 0.16). The area under the curve from the receiver operating curve analysis was 0.88, 0.87, and 0.87 in the training, validation, and combined data set, respectively. The scoring model created a score of -1 to 2, yielding an of aneurysmal hemorrhage probability from 1.5% (score -1) to 70% (score 2).

CONCLUSIONS

This prospective study identifies dome-to-neck ratio >2.5, irregular shape, presence of daughter sac, absence of aspirin use, and aneurysm location at anterior communicating and posterior communicating artery as factors associated with increased risk of hemorrhagic presentation in small- to medium-sized intracranial aneurysms. Our model provides an estimate of rupture risk based on the presence or absence of these factors.

Trends in the Age of Patients Treated for Unruptured Intracranial Aneurysms from 1990 to 2020

BACKGROUND

The decision for treatment for unruptured intracranial aneurysms (UIAs) is often difficult. Innovation in endovascular devices have improved the benefit-to-risk profile especially for elderly patients; however, the treatment guidelines from the past decade often recommend conservative management. It is unknown how these changes have affected the overall age of the patients selected for treatment. Herein, we aimed to study potential changes in the average age of the patients that are being treated over time.

METHODS

A systematic search of the literature was performed to identify all studies describing the age of the UIAs that were treated by any modality. Scatter diagrams with trend lines were used to plot the age of the patients treated over time and assess the presence of a potential significant trend via statistical correlation tests.

RESULTS

A total of 280 studies including 83,437 UIAs treated between 1987 and 2021 met all eligibility criteria and were entered in the analysis. Mean age of the patients was 55.5 years, and 70.7% were female. There was a significant increasing trend in the age of the treated patients over time (Spearman r: 0.250; P < 0.001), with a 1-year increase in the average age of the treated patients every 5 years since 1987.

CONCLUSIONS

The present study indicates that based on the treated UIA patient data published in the literature, older UIAs are being treated over time. This trend is likely driven by safer treatments while suggesting that re-evaluation of certain UIA treatment decision scores may be of great interest.

DNA methylation regulator-mediated modification patterns and risk of intracranial aneurysm: a multi-omics and epigenome-wide association study integrating machine learning, Mendelian randomization, eQTL and mQTL data

BACKGROUND

Intracranial aneurysms (IAs) pose a significant and intricate challenge. Elucidating the interplay between DNA methylation and IA pathogenesis is paramount to identify potential biomarkers and therapeutic interventions.

METHODS

We employed a comprehensive bioinformatics investigation of DNA methylation in IA, utilizing a transcriptomics-based methodology that encompassed 100 machine learning algorithms, genome-wide association studies (GWAS), Mendelian randomization (MR), and summary-data-based Mendelian randomization (SMR). Our sophisticated analytical strategy allowed for a systematic assessment of differentially methylated genes and their implications on the onset, progression, and rupture of IA.

RESULTS

We identified DNA methylation-related genes (MRGs) and associated molecular pathways, and the MR and SMR analyses provided evidence for potential causal links between the observed DNA methylation events and IA predisposition.

CONCLUSION

These insights not only augment our understanding of the molecular underpinnings of IA but also underscore potential novel biomarkers and therapeutic avenues. Although our study faces inherent limitations and hurdles, it represents a groundbreaking initiative in deciphering the intricate relationship between genetic, epigenetic, and environmental factors implicated in IA pathogenesis.

Anatomical variations in the circle of Willis are associated with increased odds of intracranial aneurysms: The Tromsø study

PURPOSE

Studies on patients suggest an association between anatomical variations in the Circle of Willis (CoW) and intracranial aneurysms (IA), but it is unclear whether this association is present in the general population. In this cross-sectional population study, we investigated the associations between CoW anatomical variations and IA.

METHODS

We included 1667 participants from a population sample with 3 T MRI time-of-flight angiography (40-84 years, 46.5% men). Saccular IAs were defined as protrusions in the intracranial arteries ≥2 mm, while variants of the CoW were classified according to whether segments were missing or hypoplastic (< 1 mm). We used logistic regression, adjusting for age and IA risk factors, to assess whether participants with incomplete CoW variants had a greater prevalence of IA and whether participants with specific incomplete variants had a greater prevalence of IA.

RESULTS

Participants with an incomplete CoW had an increased prevalence of IA (OR, 2.3 [95% CI 1.05-5.04]). This was mainly driven by the variant missing all three communicating arteries (OR, 4.2 [95% CI 1.7-1 0.3]) and the variant missing the P1 segment of the posterior cerebral artery (OR, 3.6 [95% CI 1.2-10.1]). The combined prevalence of the two variants was 15.4% but accounted for 28% of the IAs.

CONCLUSION

The findings suggest that an incomplete CoW is associated with an increased risk of IA for adults in the general population.

Preventive treatment of unruptured intracranial aneurysms in adult patients with sickle cell anemia: A cohort study

BACKGROUND AND PURPOSE

Intracranial aneurysms are frequent in patients with sickle cell anemia, while subarachnoid hemorrhage is a major cause of death and disability in young adult patients. Several characteristics, such as younger age and smaller size at rupture, may incline therapeutic decision towards exclusion treatments. Clinical guidelines on treatment of unruptured intracranial aneurysms in this population are still missing. We aimed to assess the safety and efficacy of the treatment of unruptured intracranial aneurysm in patients with sickle cell anemia, using an adapted hematological preparation regimen.

PATIENTS AND METHODS

Adult patients with sickle cell anemia and treated unruptured aneurysms by endovascular therapy or neurosurgery were included in this retrospective cohort study. Treatment decision was reached after multi-disciplinary assessment. A pre-operative blood transfusion protocol was undertaken targeting a HbS below 30%. Demographic data, hematological preparation parameters and clinical and radiological outcomes were documented.

RESULTS AND CONCLUSIONS

Twenty-five procedures were performed in 18 patients encompassing 19 aneurysms treated by embolization and 6 by surgery. Median age at treatment was 34 years-old and median aneurysm dome size was 4.4 mm. Immediate aneurysm exclusion rate was 85.7% after endovascular therapy and 100% after neurosurgery. Median follow-up was 6 months, with all patients being asymptomatic at last follow-up. Two transitory ischemic neurological deficits, as well as four cases of iodine-induced encephalopathy were identified after embolization. No complication occurred after surgery. Endovascular therapy by coiling and neurosurgical treatment of unruptured intracranial aneurysms appears to be safe in patients with sickle cell anemia and should be considered given the specific hemorrhagic risk observed in this population. A rigorous hematological preparation, associated with a dedicated peri‑operative protocol and an adequate therapeutic strategy are essential prerequisites.

On the major role played by the lumen curvature of intracranial aneurysms walls in determining their mechanical response, local hemodynamics, and rupture likelihood

The properties of intracranial aneurysms (IAs) walls are known to be driven by the underlying hemodynamics adjacent to the IA sac. Different pathways exist explaining the connections between hemodynamics and local tissue properties. The emergence of such theories is essential if one wishes to compute the mechanical response of a patient-specific IA wall and predict its rupture. Apart from the hemodynamics and tissue properties, one could assume that the mechanical response also depends on the local morphology, more specifically, the curvature of the luminal surface, with larger values at highly-curved wall portions. Nonetheless, this contradicts observations of IA rupture sites more often found at the dome, where the curvature is lower. This seeming contradiction indicates a complex interaction between the hemodynamics adjacent to the aneurysm wall, its morphology, and mechanical response, which warrants further investigation. This was the main goal of this work. We accomplished this by analyzing the stress and stretch fields in different regions of the wall for a sample of IAs, which have been classified based on particular hemodynamics conditions and lumen curvature. Pulsatile numerical simulations were performed using the one-way fluid-solid interaction strategy implemented in OpenFOAM (solids4foam toolbox). We found that the variable best correlated with regions of high stress and stretch was the lumen curvature. Additionally, our data suggest a connection between the local curvature and particular hemodynamics conditions adjacent to the wall, indicating that the lumen curvature is a property that could be used to assess both mechanical response and hemodynamic conditions, and, moreover, suggest new rupture indicators based on the curvature.

Mid-to-long term safety and efficacy of Woven EndoBridge device for Treatment of intracranial wide neck aneurysms: A systematic review and meta-analysis

BACKGROUND

In recent 10 years, Woven EndoBridge(WEB) device has been used as endovascular instrumentation for treating wide neck Bifurcation aneurysms. Its safety and efficacy in the mid-term (6-24 months) and long-term (more than 24 months) follow-up period have yet to be systematically reviewed.

PURPOSE

To evaluate the WEB device safety and efficacy, relevant literature and publications were extensively reviewed, and a meta-analysis was conducted.

DATA RESOURCE

All relevant literature/publications were achieved from Pubmed, Cochrane, Embase, and Web of Science databases.

RESULTS

767 patients that were studied in 13 literature were included. The focus of this review was placed on the clinical and anatomic outcomes. Complete occlusion was achieved in 67.3% (95% CI, 59.0-75.5%) and 69.3% (95% CI, 55.7-82.8%) of the cases at mid- and long-term follow-up. The rate of adequate occlusion was 86.6% (95% CI, 83.0-90.2%) and 90.1% (95% CI, 85.5-94.4%) for the mid and long-term, respectively. 51 patients (8.8%; 95% CI,5.6-11.9%) and 18 (8.1%; 95% CI,0.8-15.5%) received retreatments during mid- and long-term follow-up, respectively. 410 patients from 427 (94.3%; 95% CI, 89.7-98.9%) showed favorable clinical outcomes. The all-cause mortality rate was 3.5% (95% CI, 1.4-5.6%), where only a few cases were related to the WEB implantation. The WEB device deployment was associated with an overall clinical complication rate of 4.1% (95% CI, 2.7-6.6%), 3 hemorrhagic (1.2%; 95% CI, 0.2-2.6%), and 30 thromboembolic (4.0%; 95% CI, 4.0- 6.0%) complications.

CONCLUSIONS

The findings reveal the satisfactory safety and effectiveness of the WEB device for the Treatment of wide-neck aneurysms during mid-to-long-term follow-up, indicating the high potential of the WEB device for wide application.

Comparison of arterial wall integration of different flow diverters in rabbits: The CICAFLOW study

BACKGROUND AND PURPOSE

New coated flow diverters (FDs) claim antithrombotic properties and increased arterial wall integration. The aim of this study is to compare in vivo endothelial coverage of coated and uncoated FD in the context of different antiplatelet regimens.

METHODS

Different FDs (Silk Vista - SV, Pipeline with Shield technology - PED shield and Surpass Evolve - SE) were implanted in the aorta of rabbits, all 3 in each animal with 3 different antiplatelet regimens: no antiplatelet therapy, aspirin alone, or aspirin and ticagrelor. Four weeks after FD implantation, angiography, flat-panel CT, and optical coherence tomography (OCT) were performed before harvesting the aorta. Extensive histopathology analyses were performed including environmental scanning electron microscopy (ESEM), multiphoton microscopy (MPM) and histological staining with qualitative and/or quantitative assessment of device coverage.

RESULTS

All 23 FDs that were implanted remained patent without hyperplasia. Qualitative stent coverage assessment revealed that there were no statistically significant differences between the FD groups (p = 0.19, p = 0.45, p = 0.40, and p = 0.84 for OCT, ESEM, MPM and histology, respectively). Quantitative neointimal measurement of histological sections also showed similar results in all 3 FD groups (p = 0.70). However, there were significant differences between the 3 groups of antiplatelet regimens (p = 0.07) with a higher rate in the no antiplatelet group (p = 0.05 versus aspirin alone and p = 0.03 versus aspirin and ticagrelor).

CONCLUSION

Our study provides evidence that FD integration into the arterial wall is similar with coated (PED shield) and uncoated devices (SV, SE), regardless of the antiplatelet regimen. FD integration with specific surface coverage should be promoted.

TRIAL REGISTRATION

APAFIS #2022011215518538.

A novel flow diverter device (Tubridge) for the treatment of intracranial aneurysms: a systematic review and meta-analysis

The flow diverter (FD) device has become a feasible and effective option for treating intracranial aneurysms. This study aimed to evaluate the efficacy and safety of Tubridge FD (TFD) in treating intracranial aneurysms and provide evidence for further research and clinical application. Electronic databases, including PubMed, Web of Science, Embase, and the Cochrane Library from inception to July 31, 2022, were searched. The eligible studies should include TFD investigations in treating intracranial aneurysms. Pooled technical success rate, complete occlusion rate, improvement rate, stable rate, symptom elimination rate, and adverse events rate were calculated with either the fixed-effects model or the random-effects model, depending on the results of tests for heterogeneity. Egger's tests were performed to assess the potential publication bias. A total of 7 studies (145 patients) were included in this study. The pooled technical success rate was 0.98, the complete occlusion rate was 0.79, the improvement rate was 0.21, and the stable rate was 0.05. One included study reported that the surgery-related mortality rate in the Tubridge group was higher than that in the control group (3.66% vs. 1.61%), while the surgery-related morbidity rate in the Tubridge group was 2.4% and that in the control group was 0. Findings of this meta-analysis indicate that TFD manifests promising and effective performance with acceptable adverse events in the treatment of intracranial aneurysms.

The current landscape of intracranial aneurysms in Africa: management outcomes, challenges, and strategies-a narrative review

Intracranial aneurysms (IAs) pose complex and potentially life-threatening challenges in Africa, where limited resources, restricted access to specialised healthcare facilities, and disparities in healthcare provision amplify the difficulties of management. Timely diagnosis and treatment are pivotal in preventing complications, including subarachnoid haemorrhage. Treatment options encompass observation, surgical clipping, endovascular coiling, and flow diversion. Positive outcomes observed in IA management in Africa include high survival rates, favourable functional outcomes, successful treatment techniques, and the absence of complications in some cases. However, negative outcomes such as postoperative complications, reduced quality of life, perioperative mortality, and the risk of recurrence persist. Challenges in IA management encompass limited access to diagnostic tools, a scarcity of specialised healthcare professionals, and an unequal distribution of services. Addressing these challenges requires interventions focused on improving access to diagnostic tools, expanding the number of trained professionals, and establishing specialised IA treatment centres. Collaboration, research, and capacity-building efforts hold significant importance in improving patient outcomes and reducing disparities in IA management across Africa.

WEB (Woven EndoBridge) device for intracranial aneurysm treatment: technical, radiological, and clinical findings in a consecutive North American cohort

BACKGROUND

Utilization of Woven EndoBridge (WEB) for treatment of intracranial aneurysms has increased due to increasing operator experience. We aimed to report our contemporary series of a North American center with the WEB, examining factors associated with occlusion rates.

METHOD

Consecutive patients (2019-2022) with intracranial aneurysms treated with WEB device were included. Through a univariate and multivariate analysis, independent predictors of adequate occlusion (RR1/RR2) were examined. Procedural and clinical results were reported.

RESULTS

A total of 104 consecutive aneurysms/patients (25 men/79 women; median age, 63 years, IQR: 55-71) were treated with single-layer WEB-SL in our institution. Seventeen patients (16%) had a ruptured aneurysm. The median aneurysm dome size was 5.5 mm (IQR = 4.5-6.5), and the most common locations were AcomA (36/104 = 34.6%), MCA bifurcation (29/104 = 27.9%), and BT (22/104 = 21.2%). The rate of technical failure was 0.9%. The median intervention time was 32 min (IQR = 25-43). Overall, 8 (7.6%) cases needed additional interventions: 4 (3.8%) additional stenting, 3 cases (3.8%) of intravenous tirofiban infusion (because of the excessive WEB protrusion), and one case (0.9%) of additional coiling (need to complete the neck occlusion). At 12-month follow-up, 67 patients were available showing 59/67 (88%) and 6/67 (9%) of complete occlusion and neck remnant, respectively on dual-energy CTA. There were no cases necessitating retreatment. Ruptured presentation (OR = 0.09, 95% CI = 0.008-0.9, p = .024), undersized WEB (OR = 15, 95% CI = 1.2-50, p = .006), WEB shape change (OR = 0.07, 95% CI = 0.001-0.6, p = .05), aneurysm neck diameter (OR = 0.4, 95% CI = 0.2-0.9, p = .05), and angle between the parent artery and the aneurysm dome (OR = 0.2, 95% CI = 0.01-0.8, p = .008) were significantly associated with occlusion status (RR1-2) at follow-up. However, in the multivariate logistic regression, these factors did not reach the statistical significance. The overall rate of morbidity was 0.9%.

CONCLUSIONS

Our contemporary North American experience on consecutive intracranial aneurysms treated with WEB confirms the medium-term efficacy of this strategy, with low procedural time and morbidity. Further research is needed to demonstrate long-term occlusion rates.

Braided stent-assisted coil embolization versus laser engraved stent-assisted coil embolization in patients with unruptured complex intracranial aneurysms

PURPOSES

Braided and laser-cut stents both are efficacious and safe for coiling intracranial aneurysms. The study aimed to compare outcomes following braided stent-assisted coil embolization versus laser engraved stent-assisted coil embolization in 266 patients who were diagnosed with unruptured intracranial aneurysms of different types and locations.

METHODS

Patients with unruptured complex intracranial aneurysms underwent braided (BSE cohort, n = 125) or laser engraved (LSE cohort, n = 141) stent-assisted embolization.

RESULTS

The deployment success rate was higher for patients of the LSE cohort than those of the BSE cohort (140 [99%] vs. 117 [94%], p = 0.0142). Seventy-one (fifty-seven percentages) and 73 (52%) were coil embolization procedure success rates of the BSE and the LSE cohorts. Periprocedural intracranial hemorrhage was higher in patients of the BSE cohort than those of the LSE cohort (8 [6%] vs. 1 [1%], p = 0.0142). Four (three percentages) patients from the LSE cohort and 3 (2%) patients from the BSE cohort had in-stent thrombosis during embolization. Permanent morbidities were higher in patients of the LSE cohort than those of the BSE cohort (8 [6%] vs. 1 [1%], p = 0.0389). Higher successful procedures (76% vs. 68%) and fewer postprocedural intracranial hemorrhage (0% vs. 5%) and mortality (0% vs. 5%) were reported for patients of the BSE cohort in posterior circulation aneurysmal location than those of the LSE cohort. Laser engraved stent has fewer problems with deployment and may have better periprocedural and follow-up outcomes after embolization.

CONCLUSIONS

Braided stent-assisted embolization should be preferred when the aneurysm is present in the posterior circulation.

Near-wall hemodynamic parameters quantification in in vitro intracranial aneurysms with 7 T PC-MRI

OBJECTIVE

Wall shear stress (WSS) and its derived spatiotemporal parameters have proven to play a major role on intracranial aneurysms (IAs) growth and rupture. This study aims to demonstrate how ultra-high field (UHF) 7 T phase contrast magnetic resonance imaging (PC-MRI) coupled with advanced image acceleration techniques allows a highly resolved visualization of near-wall hemodynamic parameters patterns in in vitro IAs, paving the way for more robust risk assessment of their growth and rupture.

MATERIALS AND METHODS

We performed pulsatile flow measurements inside three in vitro models of patient-specific IAs using 7 T PC-MRI. To this end, we built an MRI-compatible test bench, which faithfully reproduced a typical physiological intracranial flow rate in the models.

RESULTS

The ultra-high field 7 T images revealed WSS patterns with high spatiotemporal resolution. Interestingly, the high oscillatory shear index values were found in the core of low WSS vortical structures and in flow stream intersecting regions. In contrast, maxima of WSS occurred around the impinging jet sites.

CONCLUSIONS

We showed that the elevated signal-to-noise ratio arising from 7 T PC-MRI enabled to resolve high and low WSS patterns with a high degree of detail.

Assessment of the flow-diverter efficacy for intracranial aneurysm treatment considering pre- and post-interventional hemodynamics

Endovascular treatment of intracranial aneurysms with flow diverters (FD) has become one of the most promising interventions. Due to its woven high-density structure they are particularly applicable for challenging lesions. Although several studies have already conducted realistic hemodynamic quantification of the FD efficacy, a comparison with morphologic post-interventional data is still missing. This study analyses the hemodynamics of ten intracranial aneurysm patients treated with a novel FD device. Based on pre- and post-interventional 3D digital subtraction angiography image data, patient-specific 3D models of both treatment states are generated applying open source threshold-based segmentation methods. Using a fast virtual stenting approach, the real stent positions available in the post-interventional data are virtually replicated and both treatment scenarios were characterized using image-based blood flow simulations. The results show FD-induced flow reductions at the ostium by a decrease in mean neck flow rate (51%), inflow concentration index (56%) and mean inflow velocity (53%). Intraluminal reductions in flow activity for time-averaged wall shear stress (47%) and kinetic energy (71%) are present as well. However, an intra-aneurysmal increase in flow pulsatility (16%) for the post-interventional cases can be observed. Patient-specific FD simulations demonstrate the desired flow redirection and activity reduction inside the aneurysm beneficial for thrombosis formation. Differences in the magnitude of hemodynamic reduction exist over the cardiac cycle which may be addressed in a clinical setting by anti-hypertensive treatment in selected cases.

Ticagrelor versus Clopidogrel in the Dual Antiplatelet Regimen for Unruptured Intracranial Aneurysm Treated with Stent-Assisted Coil Embolization: A Single-Center Cohort Study

BACKGROUND

Dual antiplatelet therapy (DAPT) of aspirin plus clopidogrel is commonly used in patients with unruptured intracranial aneurysms treated with stent-assisted coil (SAC) embolization. However, the unpredictable clopidogrel efficacy of the 5%-55% nonresponders limits its use. Ticagrelor, as a potential alternative of clopidogrel, is an antiplatelet agent with low resistance rates but uncertain efficacy and safety in these patients.

METHODS

A single-center cohort study was performed to compare the efficacy and safety of ticagrelor with clopidogrel in the DAPT regimen in patients with unruptured intracranial aneurysms and treated with SAC. The patients with clopidogrel resistance identified as inadequate adenosine diphosphate inhibition rate determined by thromboelastography were treated with ticagrelor instead, and both drugs achieved adequate suppression of platelet aggregation when stents were implanted. The occurrence of major adverse cardiovascular and cerebrovascular events (MACCE) and bleeding events was recorded through 6 months follow-up.

RESULTS

Data from 86 patients with 99 unruptured intracranial aneurysms and treated by SAC with clopidogrel were compared with those from 108 patients with 111 aneurysms and treated with ticagrelor. Neither the baseline characteristics nor the incidence of the MACCE or bleeding events differed between the groups. Ticagrelor exerted significantly higher adenosine diphosphate inhibition rate than that of the clopidogrel. Multivariable logistic regression analysis showed that the incidence of MACCE was related to hematocrit and fibrinogen levels.

CONCLUSIONS

Ticagrelor seemed to be as effective and safe as clopidogrel for SAC in unruptured intracranial aneurysms. Hematocrit and fibrinogen levels were independent risk factors for the incidence of MACCE.

Sarcopenia as a Predictor of the Functional Outcome in Patients with Intracranial Aneurysms

INTRODUCTION

Radiological indicators in head computed tomography (CT) scan have emerged as tools to evaluate sarcopenia using the sectional area and thickness of the temporal muscle. They can be obtained by standardized measurements in preoperative image assessment of patients with brain aneurysms. We aimed to evaluate the association between functional outcomes after interventions for intracranial aneurysms (IAs) and temporal muscle thickness (TMT) and area (TMA), as surrogates of sarcopenia.

METHODS

This is a prospective observational cohort study in patients who underwent microsurgery or embolization for ruptured or unruptured IA between January 2018 and December 2019, with a 6-month follow-up. Preoperative CT scans were analyzed to measure TMT and TMA. The functional outcome was assessed by the modified Rankin Scale (mRS). The main outcome was the relationship between sarcopenia and the postoperative functional outcome.

RESULTS

A total of 361 patients were included, of whom 199 (55.1%) had ruptured and 162 (44.9%) had unruptured lesions. Larger TMA significantly predicted better functional outcomes at discharge. TMT was associated with functional outcomes at both discharge and 6 months, adjusted for rupture and hypertension. Maximizing the sum sensitivity-specificity, an optimal TMT cutoff of 6.25 mm can predict unfavorable outcomes. Maximizing the positive predictive value × negative predictive value of a product, the cutpoint was 3.55 mm.

CONCLUSIONS

Sarcopenia, represented by TMT and TMA, is associated with poorer functional results at discharge and 6-month follow-up in IA surgery. TMT below 6.25 mm was associated with unfavorable functional outcomes. These easily obtainable measurements may improve the decision-making process for patients with IAs.

A comparison of antiplatelet therapy during the peri- and post-operative periods following flow-diverting stent insertion for unruptured intracranial aneurysms: A systematic review

BACKGROUND

Flow diverters (FDs) are neuroendovascular stents indicated for the management of unruptured intracranial aneurysms. Due to their composition, dual antiplatelet therapy (DAPT) is essential during the peri- and post-operative periods to prevent thromboembolic events. However, there is limited consensus within the scientific community regarding which antiplatelets to use and dosing following neuroendovascular treatment of aneurysms.

METHOD

A systematic search of four electronic databases was conducted during November 2020 that included studies published between January 2010 and November 2020. Eligibility for inclusion included primary research articles, published in the English language and use of flow-diverting intracranial stents. Studies were excluded if they utilised combined therapies (e.g. FD with stent-assisted coiling), animal studies, clinical trial protocols and study population of less than 10 subjects.

RESULTS

Eighteen studies were identified for inclusion with a total of 1312 patients with 1355 unruptured intracranial aneurysms treated with FDs. Of these, 13 studies primarily investigated the use of clopidogrel with aspirin with low rates of haemorrhagic and thromboembolic complications. A forest plot of nine of these studies showed average efficacy of 88% at 95% confidence interval (CI) (SD + 5%) with 63% heterogeneity.

CONCLUSIONS

The large proportion of studies investigating clopidogrel and aspirin antiplatelet therapy presents a challenge in comparing antiplatelet regimens. Although prasugrel and ticagrelor have been identified as suitable alternatives to clopidogrel, these were based on studies with small cohort sizes. Glycoprotein IIb/IIIa inhibitors may be efficacious as rescue therapy for intra-procedural thrombosis. Further research is required to determine which antiplatelet is most suitable.

Hemodynamics of anterior circulation intracranial aneurysms with daughter blebs: investigating the multidirectionality of blood flow fields

Recent advances in diagnostic neuroradiological imaging, allowed the detection of unruptured intracranial aneurysms (IAs). The shape - irregular or multilobular - of the aneurysmal dome, is considered as a possible rupture risk factor, independently of the size, the location and patient medical background. Disturbed blood flow fields in particular is thought to play a key role in IAs progression. However, there is an absence of widely-used hemodynamic indices to quantify the extent of a multi-directional disturbed flow. We simulated blood flow in twelve patient-specific anterior circulation unruptured intracranial aneurysms with daughter blebs utilizing the spectral/hp element framework Nektar++. We simulated three cardiac cycles using a volumetric flow rate waveform while we considered blood as a Newtonian fluid. To investigate the multidirectionality of the blood flow fields, besides the time-averaged wall shear stress (TAWSS), we calculated the oscillatory shear index (OSI), the relative residence time (RRT) and the time-averaged cross flow index (TACFI). Our CFD simulations suggest that in the majority of our vascular models there is a formation of complex intrasaccular flow patterns, resulting to low and highly oscillating WSS, especially in the area of the daughter blebs. The existence of disturbed multi-directional blood flow fields is also evident by the distributions of the RRT and the TACFI. These findings further support the theory that IAs with daughter blebs are linked to a potentially increased rupture risk.