Braids and beyond: a comprehensive study on pipeline device braid stability from PREMIER data.

BACKGROUND: The pipeline embolization device (PED) has been increasingly used to treat brain aneurysms; however, concerns have been raised about braid stability with newer drawn filled tubing technology devices. OBJECTIVE: To evaluate braid stability of PED early generations using data from the PREMIER trial. METHODS: All consecutive intracranial aneurysms treated with PED (Classic and Flex) within the PREMIER trial were reviewed for braid stability (fish mouthing, foreshortening, braid bump, braid collapsing). Immediate postprocedure cone-beam CT and angiography were compared with 1- and 2- years' follow-up. Analyses included safety, measured with the modified Rankin Scale (mRS) score, including +1 mRS point and a good clinical outcome (mRS score 0-2), vessel stenosis ≥50%, effectiveness measured with Raymond-Roy Scale, and re-treatment rates. RESULTS: 133/141 aneurysms had a complete dataset. 8/133 (6%) aneurysms showed braid deformations. Inter-reader agreement was excellent (κ=0.83). Braid deformations were statistically significantly associated with in-stent vessel stenosis >50% (P=0.029), without impact on effectiveness or safety. Fish mouthing was found in 1/133 (0.75%) at 1 year, causing >50% vessel stenosis. Foreshortening occurred in 6/133 (4.5%), and braid bump in 1/133 (0.75%) associated with severe in-stent stenosis. Four other cases (3.0%) of asymptomatic in-stent stenosis due to neointimal hyperplasia were seen without braid changes. No new braid stability deformations were found at the 2-year follow-up. CONCLUSION: Our study demonstrates excellent braid stability among patients treated with the PED Classic and Flex in the PREMIER trial. Within the uncommon braid changes observed, none affected the PED safety or efficacy. TRIAL REGISTRATION NUMBER: NCT02186561.

Endovascular thrombectomy for severe cerebral venous thrombosis: A comprehensive meta-analysis assessing safety and efficacy.

BACKGROUND: Cerebral sinus venous thrombosis (CSVT) has traditionally been treated medically with systemic anticoagulation. Recent advances in endovascular therapy (EVT) may represent an alternative treatment to medical therapy for CSVT. We conducted a systematic review and meta-analysis to evaluate the use of EVT for CSVT. METHODS: We conducted a systematic literature review using PubMed, Embase, Scopus, and Web of Science. We included studies that reported outcomes following EVT for CSVT. The primary outcome of interest was rate of modified Rankin Scale (mRS) 0-2. Secondary outcomes of interest were rates of complete, partial, and failed recanalization, mortality, and new or expansion of hematoma. We calculated pooled rates (%) and their corresponding 95% confidence intervals (CIs). RESULTS: Thirty-eight studies with 682 patients were included. Rate of mRS 0-2 was 82.6% (95% CI, 75.3%-88.0%). Rate of complete recanalization was 60.9% (95% CI, 49.1%-71.5%), rate of partial recanalization was 34.2% (95% CI, 24.1%-45.9%), and rate of failed recanalization was 5.4% (95% CI, 3.1%-9.2%). Rate of mortality was 6.7% (95% CI, 4.1%-10.8%), and rate of new hematoma or expansion of hematoma was 5.1% (2.9%-8.8%). CONCLUSIONS: In this systematic review and meta-analysis, EVT for CSVT was associated with favorable rates of mRS 0-2 and recanalization. Furthermore, EVT was associated with a promising safety profile. Future prospective, comparative studies are warranted to assess EVT for CSVT.

Reevaluating the role of heparin during mechanical thrombectomy for acute ischemic stroke: Increased risks without functional benefit.

BACKGROUND: Heparin may be administered during mechanical thrombectomy (MT) for acute ischemic stroke due to large vessel occlusions (AIS-LVO), with the aim of enhancing reperfusion and improving patient outcomes. The uncertain balance between risks and benefits of administering heparin during MT prompted us to perform this systematic review and meta-analysis. METHODS: A comprehensive search was conducted in PubMed, Embase, and Scopus to find studies that report the safety or efficacy of administering heparin during MT for AIS-LVO. Meta-analysis was performed using the random effects model. In case of significant heterogeneity a subgroup analysis was performed. RESULTS: From 2398 screened records, we included 15 studies. Rate of favorable functional outcome (90 day modified Rankin Scale 0-2 (mRS 0-2)) was lower among patients who received heparin (OR, 0.88 [95 %CI 0.79-0.98]; p=.023). Risk of distal embolization was higher in patients who received heparin (OR, 1.25 [95 %CI 1.01-1.55]; p=.04). The subgroup analysis showed that patients who received intravenous thrombolysis (IVT) had higher risk of Symptomatic intracranial hemorrhage (sICH) (OR, 2.94 [95 %CI 1.30-6.63]; p=.009) and lower rate of mRS 0-2 (OR, 0.66 [95 %CI 0.50-0.87]; p=.004). Heparin use didn't affect successful reperfusion rate (Thrombolysis in cerebral infarction ≥2B), mortality or any ICH risk. CONCLUSION: Overall, our analysis indicates that administering heparin during MT for AIS-LVO correlates with worse clinical outcomes and increased distal embolization rates. Moreover, it is linked to a higher risk of sICH in patients who receive IVT. Consequently, the routine utilization of heparin during MT should be reconsidered.

pRESET thrombectomy device outcomes in patients with acute ischemic stroke: A systematic review and meta-analysis.

BACKGROUND: Many devices are used to perform mechanical thrombectomy in the setting of large vessel occlusion acute ischemic stroke. We sought to evaluate the efficacy and safety of pRESET stent-retriever systems. METHODS: We conducted a comprehensive systematic review and meta-analysis following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Relevant studies up to March 2024 were retrieved from PubMed, Scopus, Web of Science, and Embase databases. RESULTS: A total of 8 papers met the inclusion/exclusion criteria comprising a total of 1140 participants (average age 72.4 ± 11.9, female percentage (50%). Preintervention intravenous thrombolysis was utilized in 46.5% (range 32.9-65.4) of patients, with a median National Institute of Health Stroke Scale at presentation of 15 (range 0-38). The middle cerebral artery was the most commonly affected artery, with a prevalence of 76.4% (range 62.8-100). The pRESET stent-retriever systems demonstrated a first-passing effect rate of 53.4% [95% confidence interval [CI] 44.8; 61.7] and a final thrombolysis in cerebral infarction 2b-3 grade rate of 90.41% [95% CI 82.13; 95.08]. Ninety-day modified Rankin Scale (0-2) rate was 42.2% [95% CI 27.6; 58.4], and 90-day mortality rate was 15.1% [95% CI 9.8; 22.6]. Postintervention hemorrhage occurred at a rate of 28.6% [CI 17.2; 43.6]. CONCLUSION: Our systematic review and meta-analysis describes the efficacy of the pRESET stent retriever system in managing acute ischemic stroke patients. The pRESET device was found to have a similar safety and efficacy profile to other mechanical thrombectomy devices currently in use.

Cardiac CT vs Echocardiography for Intracardiac Thrombus Detection in Ischemic Stroke: A Systematic Review and Meta-Analysis of 43 Studies.

BACKGROUND AND OBJECTIVES: Ischemic stroke, a leading cause of mortality, necessitates understanding its mechanism for effective prevention. Echocardiography, especially transesophageal echocardiography (TEE), is the gold standard for detection of cardiac sources of stroke including left atrial thrombus, although its invasiveness, operator skill dependence, and limited availability in some centers prompt exploration of alternatives, such as cardiac CT (CCT). We conducted a systematic review and meta-analysis assessing the ability of CCT in the detection of intracardiac thrombus compared with echocardiography. METHODS: We searched 4 databases up through September 8, 2023. Major search terms included a combination of the terms "echocardiograph," "CT," "TEE," "imaging," "stroke," "undetermined," and "cryptogenic." The current systematic literature review of the English language literature was reported in adherence to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses reporting guidelines. We assessed risk of bias using the QUADAS-2 tool and used random-effects meta-analysis to calculate different diagnostic metrics. RESULTS: The meta-analysis investigating CCT vs echocardiography for intracardiac thrombus detection yielded a total of 43 studies of 9,552 patients. Risk-of-bias assessment revealed a predominantly low risk of bias in the flow and timing, index test, and patient selection domains and a predominantly unclear risk of bias in the reference standard domain. The analysis revealed an overall sensitivity of 98.38% (95% CI 89.2-99.78) and specificity of 96.0% (95% CI 92.55-97.88). Subgroup analyses demonstrated that delayed-phase, electrocardiogram-gated CCT had the highest sensitivity (100%; 95% CI 0-100) while early-phase, nongated CCT exhibited a sensitivity of 94.31% (95% CI 28.58-99.85). The diagnostic odds ratio was 98.59 (95% CI 44.05-220.69). Heterogeneity was observed, particularly in specificity and diagnostic odds ratio estimates. DISCUSSION: CCT demonstrates high sensitivity, specificity, and diagnostic odds ratios in detecting intracardiac thrombus compared with traditional echocardiography. Limitations include the lack of randomized controlled studies, and other cardioembolic sources of stroke such as valvular disease, cardiac function, and aortic arch disease were not examined in our analysis. Large-scale studies are warranted to further evaluate CCT as a promising alternative for identifying intracardiac thrombus and other sources of cardioembolic stroke.

Detection rate of gastrin-releasing peptide receptor (GRPr) targeted tracers for positron emission tomography (PET) imaging in primary prostate cancer: a systematic review and meta-analysis.

The gastrin-releasing peptide receptor (GRPr) has gained recognition as a promising target for both diagnostic and therapeutic applications in a variety of human cancers. This study aims to explore the primary tumor detection capabilities of [68Ga] Ga-GRPr PET imaging, specifically in newly diagnosed intra-prostatic prostate cancer lesions (PCa). Following PRISMA-DTA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses of Diagnostic Test Accuracy Studies) guidelines, a systematic literature search was conducted using the Medline, Embase, Scopus, and Web of Science databases. Data regarding patient characteristics and imaging procedure details-including the type of radiotracer used, administered activity, image acquisition time, scanner modality, criteria, and detection rate of index test-were extracted from the included studies. The pooled patient-and lesion-based detection rates, along with their corresponding 95% confidence intervals (CI), were calculated using a random effects model. The final analysis included 9 studies involving 291 patients and 350 intra-prostatic lesions with [68Ga] Ga-GRPr PET imaging in primary PCa. In per-patient-based analysis of [68Ga] Ga-GRPr PET imaging, the pooled detection rates of overall and patients with Gleason score ≥ 7 were 87.09% (95% CI 74.98-93.82) and 89.01% (95% CI 68.17-96.84), respectively. In per-lesion-based analysis, the pooled detection rate [68Ga] Ga-GRPr PET imaging was 78.54% (95% CI 69.8-85.29). The pooled detection rate mpMRI (multiparametric magnetic resonance imaging) in patient-based analysis was 91.85% (95% CI 80.12-96.92). The difference between the detection rates of the mpMRI and [68Ga] Ga-GRPr PET imaging was not statistically significant (OR 0.90, 95% CI 0.23-3.51). Our findings suggest that [68Ga] Ga-GRPr PET imaging has the potential as a diagnostic target for primary PCa. Future research is needed to determine the effectiveness of [68Ga] Ga-GRPr PET in delivering additional imaging data and guiding therapeutic decisions.

Efficacy and safety of flow diverters in retreatment of recurrent intracranial aneurysms-A systematic review and meta-analysis.

BACKGROUND AND PURPOSE: Treatment of recurrent intracranial aneurysms after their initial therapy has been a significant challenge in the field of neurointervention. Recently flow diverters stents are widely used for treating intracranial aneurysms. In this systematic review and meta-analysis, we assessed the safety and efficacy of flow diverter in treating recurrent or recanalized intracranial aneurysms. METHODS: This meta-analysis is reported following the PRISMA 2020 guidelines. We conducted a systematic review of literature in the PubMed, Embase, Web of Sciences, and Scopus databases. Pooled prevalence and the corresponding 95% are calculated from extracted data using a random-effect model. RESULTS: The systematic literature search included 21 studies involving 411 patients, with 135 (32.8%) being male and 276 (67.2%) being females with a total number of 447 aneurysms. The overall rate of adequate occlusion was 90.67% (95% CI: 84.23%-94.65%), and the rates were comparable between the surgery (93.48%), coiling (91.78%), and stenting (85.77%) groups. The overall pooled rate of complete occlusion was 81.80 (95% CI: 71.14%-89.13%). On doing a subgroup analysis, the complete occlusion rates were 89.68%, 84.39%, and 73.47% for the surgery, coiling, and stenting groups, respectively. The overall mortality rate and achieving modified Rankin scale score of 0-2 was 1.28% (95% CI: 0.45%-3.64%) and (95% CI: 89.92%-97.84%), respectively. No significant heterogeneity is noted in the included studies. CONCLUSION: Flow diverter stents are an effective and safe method for retreating recurrent or residual intracranial aneurysms with a high rate of complete and adequate occlusion. The rate of mortality, intracerebral hemorrhage, and overall and procedural complications following using flow diverters for intracranial aneurysms is low.

Optimizing the hemodynamics of hand injections in neuroangiography.

PURPOSE: Optimizing the preparation of a 10 ml syringe for manual injection of contrast media can help operators obtain easier and faster injections. This study aims to compare the flow rates of different contrast media injection methods. METHODS: Different contrast media solutions were compared: 100% contrast (10 ml contrast), mixed contrast solution (8:2 contrast/saline), and layered contrast below saline ("Parfait") in different volumes. Contrast media were injected at room temperature (20°C) and after heating (37°C). Four operators injected 10 ml syringes filled with different mediums through 5-French angiographic catheters. The average flow rate was used to compare different contrast injection mediums. The Kruskal-Wallis test with post-hoc pairwise comparisons using Bonferroni correction or Mann-Whitney U-tests were employed depending on the type of comparison. RESULTS: Compared to the 100% contrast solution, every Parfait media and mixed contrast solution demonstrated significantly higher flow rates (p < 0.001). The 5 ml saline Parfait had the highest flow rate among the Parfait solutions. The 5 ml saline Parfait and the mixed solution had comparable flow rates (p = 0.237). Higher flow rates were observed upon heating both 100% contrast (p < 0.001) and mixed contrast solutions (p < 0.001) in comparison to their flow rates at room temperature. CONCLUSION: This study demonstrates the capability of the Parfait and mixed contrast injections to achieve higher flow rates than the 100% contrast solutions. Heating the contrast media to 37°C also proves to be a viable strategy for further enhancing the flow rates for 100% and mixed contrast solutions.

Flow diverter braid deformation following treatment of cerebral aneurysms: incidence, clinical relevance, and potential risk factors.

BACKGROUND: Although flow diverters (FDs) have benefited from several technical improvements, recently concerns have arisen regarding the braid stability after implantation. Thus, we investigated frequency, predictive factors, and clinical impact of the phenomenon of FD braid deformation (FDBD). METHODS: Consecutive intracranial aneurysms (IAs) treated with various FDs, between January 2018 and July 2023, were reviewed to identify FDBD (defined as the deformation of a FD without any external force applied to it). Patient, aneurysm, procedural, and FD characteristics were retrieved and analyzed using univariate and multivariable analyses. Morbidity is defined as a score of +1 in the modified Rankin Scale at 3 months. RESULTS: In total, 245 FD procedures (271 FDs implanted; 25 multiple IAs treated with 1 FD) in 228 patients; FDBD was observed in 36/245 cases (14.7%), mainly at follow-up angiography (32/36, 88.9%); fish-mouthing was the most frequent FDBD. Morbidity was related to fish-mouthing and braid collapse and was significantly higher in the FDBD group after retreatment (p=0.04). Drawn filled tubing with platinum (DFT) (adjusted odds ratio (aOR)=7.0, 95% CI 3.0 to 17.5; p<0.001) and FD diameter (aOR=2.2, 95% CI 1.3 to 4.1; p<0.01) were identified as independent predictors of FDBD. The metal alloy composing the FD (p=0.13) and coated surfaces were not significantly associated with FDBD (p=0.54 in multivariable analysis). CONCLUSIONS: FDBD is a frequent phenomenon observed in about 15% of cases, and it was responsible for higher morbidity. Only FD characteristics (DFT and FD diameter) were independent determinants of FDBD. Future research should focus on the impact of novel braid configurations and materials on braid stability.

Neck apposition is a key factor for aneurysm occlusion after Woven EndoBridge device embolization.

BACKGROUND: Sealing of the aneurysm neck with a Woven EndoBridge (WEB) device is recommended for disrupting the blood flow inside the aneurysm. This study investigates the relationship between WEB neck apposition and aneurysm occlusion rates. METHODS: Aneurysms treated with a WEB from March 2017 to May 2022 at a single center were included. WEB neck apposition (poor/good) and WEB protrusion (yes/no) were evaluated on post-detachment high resolution cone beam CT images. Angiographic occlusion was assessed with the Bicêtre Occlusion Scale score (BOSS). Univariate and multivariable analysis tested the association between neck apposition and occlusion rates. RESULTS: The study included 159 aneurysms in 141 patients (mean age 55.8±11.2 years; 64.2% women). Good neck apposition and protrusion were noted in 123 (77.4%) and 30 (18.9%) cases, respectively. Inter-rater agreements were good for neck apposition (κ=0.75) and protrusion (κ=0.78). Complete and adequate occlusion was achieved in 104 (65%) and 130 (82%) cases, respectively (median follow-up 18 months). Good neck apposition was a strong independent predictor for both adequate (adjusted OR (aOR)=5.9, 95% CI 2.4 to 14.9; P<0.001) and complete occlusion (aOR=7.1, 95% CI 3.0 to 18.1; P<0.001). Protrusion was more frequent in the adequate occlusion group versus the aneurysm recurrence group without reaching statistical significance (P=0.06), but was associated with more thromboembolic complications (9/30 (30%) vs 12/129 (9%); P<0.01). WEB shape modification was significantly greater in poor apposition cases (P=0.03). CONCLUSIONS: Achieving good neck apposition of the WEB strongly predicts aneurysm occlusion during follow-up. WEB protrusion should be minimized due to the increase in thromboembolic risk with limited impact on aneurysm occlusion.

Risk of Hemorrhagic Transformation after Mechanical Thrombectomy without versus with IV Thrombolysis for Acute Ischemic Stroke: A Systematic Review and Meta-analysis of Randomized Clinical Trials.

BACKGROUND: When treating acute ischemic stroke due to large-vessel occlusion, both mechanical thrombectomy and intravenous (IV) thrombolysis carry the risk of intracerebral hemorrhage. PURPOSE: This study aimed to delve deeper into the risk of intracerebral hemorrhage and its subtypes associated with mechanical thrombectomy with or without IV thrombolysis to contribute to better decision-making in the treatment of acute ischemic stroke due to large-vessel occlusion. DATA SOURCES: PubMed, EMBASE, and Scopus databases were searched for relevant studies from inception to September 6, 2023. STUDY SELECTION: The eligibility criteria included randomized clinical trials or post hoc analysis of randomized controlled trials that focused on patients with acute ischemic stroke in the anterior circulation. After screening 4870 retrieved records, we included 9 studies (6 randomized controlled trials and 3 post hoc analyses of randomized controlled trials) with 3241 patients. DATA ANALYSIS: The interventions compared were mechanical thrombectomy + IV thrombolysis versus mechanical thrombectomy alone, with the outcome of interest being any form of intracerebral hemorrhage and symptomatic intracerebral hemorrhage after intervention. A common definition for symptomatic intracerebral hemorrhage was pooled from various classification systems, and subgroup analyses were performed on the basis of different definitions and anatomic descriptions of hemorrhage. The quality of the studies was assessed using the revised version of Cochrane Risk of Bias 2 assessment tool. Meta-analysis was performed using the random effects model. DATA SYNTHESIS: Eight studies had some concerns, and 1 study was considered high risk. Overall, the risk of symptomatic intracerebral hemorrhage was comparable between mechanical thrombectomy + IV thrombolysis and mechanical thrombectomy alone (risk ratio, 1.24 [95% CI, 0.89-1.72]; P = .20), with no heterogeneity across studies. Subgroup analysis of symptomatic intracerebral hemorrhage showed a non-significant difference between 2 groups based on the National Institute of Neurological Disorders and Stroke (P = .3), the Heidelberg Bleeding Classification (P = .5), the Safe Implementation of Thrombolysis in Stroke-Monitoring Study (P = .4), and the European Cooperative Acute Stroke Study III (P = .7) criteria. Subgroup analysis of different anatomic descriptions of intracerebral hemorrhage showed no difference between the 2 groups. Also, we found no difference in the risk of any intracerebral hemorrhage between two groups (risk ratio, 1.10 [95% CI, 1.00-1.21]; P = .052) with no heterogeneity across studies. LIMITATIONS: There was a potential for performance bias in most studies. CONCLUSIONS: In this systematic review and meta-analysis, the risk of any intracerebral hemorrhage and symptomatic intracerebral hemorrhage, including its various classifications and anatomic descriptions, was comparable between mechanical thrombectomy + IV thrombolysis and mechanical thrombectomy alone.

Triple Aspiration versus Conventional Aspiration Techniques: A Randomized In Vitro Evaluation.

BACKGROUND AND PURPOSE: A single-aspiration maneuver using a large-volume syringe is a common and effective technique for aspiration thrombectomy. Multiple aspiration cycles using large aspiration syringes have been proposed as a means to improve the efficacy over single aspiration. In this study, we sought to investigate the efficacy of a "triple aspiration technique" in which a large-volume syringe is cycled 3 times before catheter retraction during aspiration thrombectomy. MATERIALS AND METHODS: A 3D-printed adult vasculature was used as a benchtop thrombectomy platform. Fibrin-rich and red blood cell-rich clots were prepared in centrifuge tubes using human plasma, red blood cells, and calcium chloride. Next, clots were placed in the carotid terminus of the model, and the performances of 3 different aspiration techniques-triple syringe, single syringe, and continuous pump aspiration-were compared in a randomized manner (1:1:1). Outcomes of interest included first-pass efficacy (FPE), complete clot removal (final modified TICI 2c/3), the number of thrombectomy attempts to achieve modified TICI 2c/3, vacuum pressure, and distal embolization. The distal emboli were detected using a 70-µm cell strainer placed at the outflow of the model and quantified using an image-processing algorithm. The vacuum pressures were measured using a pressure transducer. RESULTS: A total of 102 replicates were performed, 34 for each technique. The triple-aspiration technique provided a significantly higher rate of FPE than the syringe and pump aspiration techniques (67.6% versus 41.1%, P = .02). Additionally, the triple-aspiration technique achieved complete clot removal with a significantly lower mean number of thrombectomy attempts compared with single-syringe aspiration (1.2 [SD, 0.5] versus 1.8 [SD, 0.8], P = .005). The triple-aspiration technique generated significantly higher mean vacuum pressure than both the single-syringe and vacuum pump aspiration (28.3 [SD, 0.2] versus 27.2 [SD, 0.3], P = .002 and 26.2 [SD, 0.4], P = .001, respectively). The differences in complete clot removal and distal embolization parameters were not statistically significantly different across the groups. CONCLUSIONS: Our findings suggest that the triple aspiration technique can improve FPE rates and vacuum pressure in aspiration thrombectomy. Further studies are needed to examine the safety and efficacy of triple aspiration in the clinical setting.

In vitro evaluation of flow diverter performance using a human fibrinogen-based flow model.

OBJECTIVE: Fibrin deposition represents a key step in aneurysm occlusion, promoting endothelization of implants and connective tissue organization as part of the aneurysm-healing mechanism. In this study, the authors introduce a novel in vitro testing platform for flow diverters based on human fibrinogen. METHODS: A flow diverter was deployed in 4 different glass models. The glass models had the same internal parent artery (4 mm) and aneurysm (8 mm) diameters with varying parent artery angulations (paraophthalmic, sidewall, bifurcation, and slightly curved models). The neck size and area were 4 mm and 25 mm2, respectively. Human fibrinogen (330 mg/dl) was circulated within the glass models at varying flow rates (0, 3, 4, and 5 ml/sec) with or without heparin, calcium chloride, and thrombin for as long as 6 hours or until complete fibrin coverage of the flow diverter's neck was achieved. Aneurysm neck coverage was defined as macroscopic fibrin deposition occluding the flow diverters' pores. Flow characteristics after flow diverter deployment were assessed with computational fluid dynamics analysis. The effects of flow rates, heparin, calcium chloride, and thrombin on fibrin deposition rates were tested using 1-way ANOVA and the Tukey test. RESULTS: A total of 84 replicates were performed. Human fibrin did not accumulate on the flow diverter stents under static conditions. The fibrin deposition rate on the aneurysm neck was significantly greater with the 5 ml/sec flow rate as compared to 3 ml/sec for all models. The paraophthalmic model had the highest inflow velocity of 48.7 cm/sec. The bifurcation model had the highest maximum shear stress (SS) and maximum normalized shear stress values at the device cells at 843.3 dyne/cm2 and 35.1 SS/SSinflow, respectively. The fibrin deposition rates of the paraophthalmic and bifurcation models were significantly higher than those of sidewall and slightly curved models for all additive or flow rate comparisons (p = 0.001 for all comparisons). The incorporation of thrombin significantly increased the fibrin deposition rates across all models (p = 0.001 for all models). CONCLUSIONS: Rates of fibrin deposition varied widely across different configurations and additive conditions in this novel in vitro model system. Fibrin accumulation started at the aneurysm inflow zone where flow velocity and shear stress were the highest. The primary factors influencing fibrin deposition included flow velocities, shear stress, and the addition of thrombin at a physiological concentration. Further research is needed to test the clinical utility of fibrinogen-based models for patient-specific aneurysms.

Pipeline versus non-pipeline flow diverter treatment for M1 aneurysms: A systematic review and meta-analysis.

BACKGROUND: The flow diversion treatment of aneurysms located distal to the Circle of Willis has recently increased in frequency. We conducted a systematic review and meta-analysis of the clinical and radiological outcomes of flow diverter (FD) embolization in treating M1 aneurysms. METHODS: PubMed, Web of Science, Ovid Medline, Ovid Embase, and Scopus were searched up to May 2024 using the Nested Knowledge platform. We included studies assessing the long-term clinical and radiological outcomes for M1 aneurysms. Results of FDs classified as Pipeline Embolization Devices (PED) versus other types of FDs. Angiographic occlusion rates, ischemic and hemorrhagic complications, and favorable clinic outcomes were included. All data were analyzed using R software version 4.2.2. RESULTS: Thirteen studies with 112 total patients (58 patients for PED and 54 patients for other FD devices) were included in our meta-analysis. The overall adequate (complete + near-complete) occlusion rates were 85.1%. The complete occlusion rate was higher with PED than with other FD devices (72.9% PED and 41.6% for non-PED FDs, respectively, p-value <.01). The ischemic complications were 9.9% and 9.0% for the PED and non-PED groups, respectively (p-value = .89). The overall modified Rankin Scale 0-2 was 100% for the non-PED and 97.1% for the PED group (p-value = .51). In-stent stenosis rate was 7.5% for PED devices compared to 2.6% in the non-PED group (p-value = .35). CONCLUSIONS: This relatively small meta-analysis showed high rates of adequate and complete occlusion in FD treatment of M1 segment aneurysms, with favorable safety profiles. PEDs were associated with higher rates of complete aneurysm occlusion compared to other types of FDs.

Impact of frailty on post-operative outcomes following subarachnoid hemorrhage: A systematic review and meta-analysis.

BACKGROUND: Subarachnoid hemorrhage (SAH) is associated with high rates of mortality and morbidity, particularly among elderly patients. The presence of frailty may impact survival rates in patients with SAH. In this study, we aim to investigate the impact of frailty on the clinical outcomes in SAH patients. METHODS: We conducted a systematic review and meta-analysis following the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. Relevant papers through December 2023 were retrieved from PubMed, Scopus, Web of science, and Embase. RESULTS: A total of 5 studies met inclusion/exclusion criteria with an aggregate 39,221 non-frail patients (mean age 52.4 ± 5.2 yr; 62.1 % Female), and 79,416 frail patients (mean age 61.1 ± 5.4 yr; 69.0 % Female). Frailty was significantly associated with higher mortality ratio (Odds ratio (OR)= 2.09; CI [1.04: 4.20], p= 0.04), and increased length of hospital stay (OR= 1.40; CI [1.07: 1.83], p= 0.015). Additionally, frailty was associated with higher odds of external ventricular drain insertion, the need of tracheostomy/endoscopic gastrostomy, increased risk of deep vein thrombosis, and postoperative neurological complications. CONCLUSION: Frailty is associated with worse clinical outcomes and higher mortality rates in SAH patients. Our findings highlight that frailty, when considered alongside other established prognostic factors, serves as crucial predictor for peri-operative complications and overall hospital course in SAH patients.

The Utilization of Systematic Reviews and Meta-Analyses in Stroke Guidelines.

BACKGROUND: Stroke guideline statements are important references for clinicians due to the rapidly evolving nature of treatments. Guideline statements should be informed by up-to-date systematic reviews (SRs) and meta-analyses (MAs) because they provide the highest level of evidence. To investigate the utilization of SRs/MAs in stroke management guidelines, we conducted a literature review of guidelines and extracted relevant information regarding SRs/MAs. METHODS: A literature review was conducted in PubMed with supplementation using the Trip medical database with the term "stroke" as the target population, followed by using the filter "guidelines". We extracted the number of included SRs/MAs, the years of publication, the country of origin, and other characteristics of interest. Descriptive statistics were generated using the R software version 4.2.1. RESULTS: We included 27 guideline statements. The median number of overall SRs or MAs within the guidelines was 4.0 (interquartile range [IQR] = 2-9). For MAs only, the median number included in the guidelines was 3.0 (IQR = 2.0-5.5). Canadian guidelines had the oldest citations, with a median gap of 12.0 (IQR = 5.2-18.0) years for the oldest citation, followed by European (median = 12; IQR = 9.5-13.5) and US (median = 10.0; IQR = 5.2-16) guidelines. CONCLUSIONS: Stroke guideline writing groups and issuing bodies should devote greater effort to the inclusion of up-to-date SRs/MAs in their guideline statements so that clinicians can reference recent data with the highest level of evidence.

Radiopaque FeMnN-Mo composite drawn filled tubing wires for braided absorbable neurovascular devices.

Flow diverter devices are small stents used to divert blood flow away from aneurysms in the brain, stagnating flow and inducing intra-aneurysmal thrombosis which in time will prevent aneurysm rupture. Current devices are formed from thin (∼25 µm) wires which will remain in place long after the aneurysm has been mitigated. As their continued presence could lead to secondary complications, an absorbable flow diverter which dissolves into the body after aneurysm occlusion is desirable. The absorbable metals investigated to date struggle to achieve the necessary combination of strength, elasticity, corrosion rate, fragmentation resistance, radiopacity, and biocompatibility. This work proposes and investigates a new composite wire concept combining absorbable iron alloy (FeMnN) shells with one or more pure molybdenum (Mo) cores. Various wire configurations are produced and drawn to 25-250 µm wires. Tensile testing revealed high and tunable mechanical properties on par with existing flow diverter materials. In vitro degradation testing of 100 µm wire in DMEM to 7 days indicated progressive corrosion and cracking of the FeMnN shell but not of the Mo, confirming the cathodic protection of the Mo by the FeMnN and thus mitigation of premature fragmentation risk. In vivo implantation and subsequent µCT of the same wires in mouse aortas to 6 months showed meaningful corrosion had begun in the FeMnN shell but not yet in the Mo filament cores. In total, these results indicate that these composites may offer an ideal combination of properties for absorbable flow diverters.

Creating elastase aneurysms in rabbits: a video primer.

The New Zealand rabbit elastase-induced arterial aneurysm of the right common carotid artery remains a widely used model for assessing the effectiveness and safety of new neuroendovascular devices.1 This model offers a simple and reliable platform for pre-clinical in vivo investigations, crucial for comprehending the biological processes underlying aneurysm healing after endovascular treatment.2 Notably, the induced aneurysm exhibits morphological, hemodynamic, and histological characteristics similar to human intracranial aneurysms. The creation of the aneurysm is performed using open and endovascular techniques. Each step of the procedure requires a meticulous and controlled gesture to ensure reproducibility of the aneurysm and minimize animal misuse. In video 1 we present a step-by-step procedural guide for aneurysm creation and follow-up. We hope this resource will help in promoting this model and provide useful guidance for researchers in the field.neurintsurg;jnis-2024-021912v1/V1F1V1Video 1Surgical procedure of creating elastase-induced aneurysms in rabbits.