High thrombin-activatable fibrinolysis inhibitor expression in thrombi from stroke patients in elevated estrogen states.

BACKGROUND: The risk of acute ischemic stroke (AIS) associated with high estrogen states, including pregnant patients and those using oral contraceptives, has been well documented. We described the histological composition of thrombi collected in these cases. METHODS: From a prospective tissue registry (STRIP registry) of thrombi retrieved during mechanical thrombectomy for AIS, we identified 5 patients with high estrogen states: 1 post-partum patient, 1 undergoing hormone replacement therapy and 3 consuming oral contraceptive pills. Five male control patients were randomly chosen matched by age. Immunohistochemistry for CD42b (platelets), von Willebrand factor (vWF), thrombin-activatable fibrinolysis inhibitor (TAFI), fibrinogen and plasminogen activator inhibitor-1 (PAI-1) was performed. Expression was quantified using Orbit Image Software. Student's t-test was performed as appropriate. RESULTS: Mean TAFI content for the high estrogen state group was higher than controls (25.6 ± 11.9% versus 9.3 ± 9.0%, p = 0.043*). Mean platelet content for the high estrogen state group was lower than controls (41.7 ± 10.6% versus 61.8 ± 12.9%, p = 0.029*). No significant difference was found in vWF, fibrinogen and PAI-1 expression. Mean time to recanalize was higher in the high estrogen state group compared to the control group (57.8 ± 27.6 versus 22.6 ± 11.4 min, p = 0.0351*). The mean number of passes required was higher in the high estrogen group compared to controls 4.6 versus 1.2, p = 0.0261*). CONCLUSIONS: TAFI expression, a powerful driver of thrombosis, was significantly higher in stroke thrombi among patients with high estrogen states compared to controls.

Endovascular embolization of cerebrospinal fluid-venous fistula: a comprehensive systematic review on its efficacy and safety for the management of spontaneous intracranial hypotension.

Cerebrospinal fluid (CSF)-venous fistula can cause spontaneous intracranial hypotension (SIH) and poses a significant diagnostic and management challenge. This study aims to provide a comprehensive overview of the clinical and radiological outcomes of endovascular embolization as a novel treatment approach for CSF-venous fistula in patients with SIH. This systematic review adheres to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 statement. The primary outcome was the efficacy of the embolization procedure in occlusion of the CSF-venous fistula, and secondary outcomes included procedural complications and improvement of clinical symptoms and radiological findings. A total of nine studies consisting of 77 patients met the inclusion criteria. Orthostatic and/or Valsalva headache was the most common symptom. The mean age of the patients was 57 ± 8.9 years, and females accounted for 59.7% (46/77) of the cases. Sixty-five (84.4%) patients reported complete resolution or significant improvement in symptoms. The Bern score, Headache Impact Test-6, and the Patient Global Impression of Change scales demonstrated significant improvements in radiological findings and patients' quality of life. Following the procedure, 22 patients (28.6%) experienced rebound intracranial hypertension and 27 patients (35.1%) had transient local pain at the site of the embolization. Our study showed that endovascular embolization is a safe and effective treatment for CSF-venous fistula in patients with SIH, providing complete resolution or significant improvement of clinical symptoms and radiological findings, and positive impacts on patients' quality of life.

Common Design and Data Elements Reported on Idiopathic Intracranial Hypertension Trials: A Systematic Review.

BACKGROUND: There are an increasing number of controlled clinical trials and prospective studies, ongoing and recently completed, regarding management options for idiopathic intracranial hypertension (IIH). We present a Common Design and Data Element (CDDE) analysis of controlled and prospective IIH studies with the aim of aligning essential design and recommending data elements in future trials and enhancing data synthesis potential in IIH trials. METHODS: We used PubMed and ClinicalTrials.gov to screen for ongoing and published trials assessing treatment modalities in people with IIH. After our search, we used the Nested Knowledge AutoLit platform to extract pertinent information regarding each study. We examined outputs from each study and synthesized the data elements to determine the degree of homogeneity between studies. RESULTS: The most CDDE for inclusion criteria was the modified Dandy criteria for diagnosis of IIH, used in 9/14 studies (64%). The most CDDE for outcomes was change in visual function, reported in 12/14 studies (86%). Evaluation of surgical procedures (venous sinus stenting, cerebrospinal fluid shunt placement, and others) was more common, seen in 9/14 studies (64%) as compared with interventions with medical therapy 6/14 (43%). CONCLUSIONS: Although all studies have similar focus to improve patient care, there was a high degree of inconsistency among studies regarding inclusion criteria, exclusion criteria, and outcomes measures. Furthermore, studies used different time frames to assess outcome data elements. This heterogeneity will make it difficult to achieve a consistent standard, and thus, making secondary analyses and meta-analyses less effective in the future. Consensus on design of trials is an unmet research need for IIH.

Safety and efficacy profile of off-label use of the Pipeline Embolization Device: A systematic review and meta-analysis.

OBJECTIVE: The off-label utilization of the Pipeline Embolization Device (PED) is a common practice in numerous medical centers globally. Therefore, we conducted a systematic review and meta-analysis to evaluate the overall outcomes of this off-label usage of PEDs. METHODS: PubMed, Web of Science, Ovid Medline, Ovid Embase, and Scopus were searched up to February 2023 using the Nested Knowledge platform to identify studies assessing the off-label use of PEDs. Any use of PED outside of the FDA-approved indication granted in 2018 is considered off-label use. Overall angiographic occlusion rates, ischemic and hemorrhagic complications, mortality, retreatment rates, and favorable clinic outcomes were included. Statistical analyses were performed to compare the overall outcome rates of anterior cerebral artery(ACA) vs. middle cerebral artery(MCA) and anterior vs posterior circulation subgroups. RESULTS: We included 26 studies involving a total of 1,408 patients. The overall rate of complete occlusion was 80.3 % (95 % CI= 76.0-84.1). Subgroup analysis demonstrated a statistically significant difference in the rate of complete occlusion between anterior circulation (78.9 %) and posterior circulation (69.2 %) (p value=0.02). The rate of good clinical outcomes was 92.8 % (95 % CI= 88.8-95.4). The mortality rate was 1.4 % (95 % CI= 0.5-2.7). The overall rate of ischemic complications was 9.5 % (95 % CI= 7.7-11.6), with a comparable difference between anterior circulation (7.7 %) and posterior circulation (12.8 %) (p value=0.07). There was no statistically significant difference in MCA vs ACA subgroups in all parameters. CONCLUSIONS: Off-label use of PEDs can be a safe and effective treatment option for intracranial aneurysms. However, there is a need for more prospective, high-quality, non-industry-funded registry studies and randomized trials to test the efficacy and safety of off-label usage of PEDs and to expand its indications.

The impact of pre-stroke metformin use on clinical outcomes after acute ischemic stroke: A systematic review and meta-analysis.

OBJECTIVES: Stroke is a leading cause of mortality and disability globally, with limited treatment options available for acute ischemic stroke (AIS) patients. Type 2 diabetes mellitus (T2DM) is not only widespread but also a known risk factor for stroke. Our meta-analysis aims to assess the influence of pre-stroke metformin use on the clinical outcomes in AIS patients with T2DM. MATERIALS AND METHODS: We conducted this study following PRISMA guidelines, searching the following databases: Medline, Embase, Scopus, Web of Science, and Cochrane Central Register of Controlled Trials up to February 29, 2024. All studies providing separate data on AIS patients using metformin were included, and statistical analysis was conducted using R software to pooled odds ratios (ORs) and their corresponding 95% confidence intervals (CI). RESULTS: Out of 1051 studies, 7 met the inclusion criteria for our meta-analysis with a total of 11589 diabetic patients, including 5445 patients taking metformin and 6144 diabetic patients in the non-metformin group. Compared to the non-metformin group, the metformin group had a significantly higher rate of mRS 0-2 score at discharge (OR 1.56; 95% CI 1.25:1.95; p=< 0.01) and a lower rate of 90-day mortality (OR 0.51; 95% CI 0.42:0.61; p=< 0.01), with no significant difference in sICH (OR 0.88; 95% CI 0.47:1.64; p= 0.68) between the two groups. CONCLUSIONS: Our meta-analysis demonstrated that pre-stroke metformin use is associated with higher functional independence and lower mortality in AIS patients with T2DM.

First-pass effect in posterior acute ischemic stroke undergoing endovascular thrombectomy: A systematic review and meta-analysis.

OBJECTIVES: First-pass effect (FPE) has been shown to be a predictor of favorable clinical outcomes following endovascular thrombectomy (EVT) for acute ischemic stroke (AIS) in the anterior circulation. Literature regarding FPE for posterior circulation AIS is sparse; we conducted a systematic review and meta-analysis to explore FPE in posterior circulation stroke undergoing EVT. MATERIALS AND METHODS: We conducted a systematic review of the English literature in PubMed, Embase, Scopus, and Web of Science. FPE was defined as thrombolysis in cerebral infarction (TICI) 2c-3 and modified FPE (mFPE) was defined as TICI 2b-3 in one pass. Definitions of non-FPE and non-mFPE varied among studies. The primary outcome of interest was modified Rankin Scale (mRS) 0-2. Secondary outcomes of interest were mRS 0-3, symptomatic intracranial hemorrhage (sICH), and mortality. We calculated odds ratios (OR) and corresponding 95% confidence intervals (CI). Heterogeneity was assessed with Q statistic and I2 test. RESULTS: Seven studies with 417 patients in the mFPE group, 942 in the non-mFPE group, 545 in the FPE group, and 1023 in the non-FPE group were included. Overall, FPE was associated with greater rates of 90-day mRS 0-2 (OR= 2.78, 95% CI= 2.11-3.65; P-value< 0.001) and mRS 0-3 (OR= 2.67, 95% CI= 1.98-3.60; P-value< 0.001); however, there was significant heterogeneity among studies for both mRS 0-2 (I2= 69%; P-value< 0.001) and mRS 0-3 (I2= 69%; P-value< 0.001). FPE and non-FPE were associated with similar rates of sICH (OR= 0.65, 95% CI= 0.40-1.07; P-value= 0.09), and no heterogeneity was observed (I2= 0%; P-value= 0.95). FPE was associated with lower rates of mortality (OR= 0.44, 95% CI= 0.33-0.58; P-value< 0.001), although heterogeneity was observed (I2= 58%; P-value= 0.01). CONCLUSIONS: FPE is associated with favorable clinical outcomes in patients undergoing EVT for posterior circulation AIS. Future studies should work to further quantify the impact of FPE on outcomes in the posterior circulation.

Differences between males and females following endovascular therapy for stroke: A systematic review and meta-analysis.

BACKGROUND: Endovascular therapy (EVT) represents the standard of care for eligible patients with acute ischemic stroke (AIS) and large vessel occlusion. To better understand differences in baseline characteristics and outcomes between males and females following EVT, we conducted a systematic review and meta-analysis. METHODS: We identified, using the Nested Knowledge AutoLit platform, prospective studies that reported 90-day outcomes in males and females treated with EVT for AIS. The primary outcome of interest was 90-day modified Rankin Scale (mRS) 0-2. Secondary outcome variables included mRS 0-1, symptomatic intracranial hemorrhage (sICH), thrombolysis in cerebral infarction (TICI) score 2b-3, and mortality. Using R software version 4.1.2, we calculated pooled odds ratios (ORs) and their corresponding 95% confidence intervals (CI). RESULTS: We included 10 studies with 10,209 patients. There was no difference between males and females in rate of mRS 0-2 (OR= 1.16; 95% CI= 0.87-1.56; P-value= 0.316); however, after removing outliers, males had higher rates of mRS 0-2 (OR= 1.40; 95% CI= 1.19-1.66; P-value< 0.001). Similar results were reported for mRS 0-1 (OR= 1.21; 95% CI= 0.93-1.56; P-value= 0.15), after removing outliers (OR= 1.32; 95% CI= 1.17-1.50; P-value< 0.001). There was no difference between males and females in rate of sICH (OR= 0.89; 95% CI= 0.74-1.08; P-value= 0.246), mortality (OR= 0.88; 95% CI= 0.74-1.05; P-value= 0.15), or TICI 2b-3 (OR= 1.19; 95% CI= 0.85-1.67; P-value= 0.309). CONCLUSIONS: Males tend to experience better outcomes following EVT for AIS, even in the setting of similar reperfusion. The mechanisms underlying this phenomenon remain unclear, and further research is warranted. EVT remains a safe and effective option for both males and females with AIS.

Diagnostic utility of superb microvascular imaging in depiction of corkscrew collaterals in Buerger's disease.

PURPOSE: To evaluate the corkscrew collaterals in Buerger's disease by superb microvascular imaging (SMI) and power Doppler ultrasonography (PDU). METHODS: We evaluated with SMI and PDU 14 patients with Buerger's disease in whom corkscrew collaterals had been identified on digital subtraction angiography (DSA). Corkscrew collaterals were classified on DSA and PDU based on their size and morphology. RESULTS: A total of 17 vascular regions of collateral vessel formation were assessed. Based on DSA classification, there were three cases of type I collaterals (arterial diameter of >2 mm with large helical pattern), seven cases of type III collaterals (arterial diameter of 1-1.5 mm with small helical pattern), and seven cases of type IV collaterals (arterial diameter of <1 mm with tiny helical pattern). On PDU, all type I collaterals on DSA appeared as "large snake" images, all type III collaterals on DSA appeared as "small snake" images, and all type IV collaterals on DSA appeared as dots. SMI imaging, both in color and monochrome mode, provided superior demonstration of the continuity of the vessel of large or small "snake" images. In cases appearing as dot pattern on PDU, color SMI was able to show continuity of the flow signal as a helical pattern. DISCUSSION: SMI is a promising new Doppler imaging technique that is superior to conventional power Doppler imaging in depiction and identification of corkscrew collaterals in Buerger's disease.

Temporal Evolution of Imaging Findings in Ossified Cephalohematoma.

BACKGROUND: Cephalohematoma is collection of blood between skull and periosteum that is confined by cranial sutures. Cephalohematomas usually resorb spontaneously within the first month of life; however, if it fails to resolve, ossified cephalohematoma may form. METHODS: Clinical archiving system and picture archiving and communication system were retrospectively reviewed for cases of birth-related cephalohematoma. Cases of ossified cephalohematomas identified on imaging were retrieved from this subset of patients. Cross-sectional imaging findings in patients with ossified cephalohematomas were evaluated for location, size of the hematoma, and contours of the inner lamella. RESULTS: Out of 115 cases of cephalohematoma, 7 cases had imaging findings consistent with ossified cephalohematoma. All ossified cephalohematomas were located parietally, with size ranging between 18 and 55 mm and the thickness of the outer rim of calcification ranging between 1.5 and 4.8 mm. The contour of inner lamella in relation to the surrounding normal cranial vault was normal in 5 cases, and inner lamella was depressed in 2 cases.Three patients had follow-up imaging available for demonstration of changes in ossified cephalohematoma. The first case was an 11 day-old boy with a cephalohematoma with no signs of calcification at the time of initial imaging. Follow-up at 2 months of age showed partial regression of hematoma cavity with marked calcification at the hematoma walls. The second case was a 3 month-old boy with ossified cephalohematoma at initial imaging. Follow-up imaging at 7 months of age showed almost total regression of hematoma cavity, and approximation of inner and outer lamella with increased thickness of the cranial vault. The third case was a 1 month-old boy with ossified cephalohematoma at initial imaging that totally resolved without residual increased bone thickness at 21-month follow-up. CONCLUSION: These 3 cases demonstrate the variability in temporal changes that may occur in ossified cephalohematomas.

Isolated Congenital Lacrimal Gland Agenesis.

Congenital alacrima is an uncommon condition marked by a lack of tear production that is present from birth. This condition often occurs in conjunction with various syndromes but can also result from isolated lacrimal gland agenesis. Congenital alacrima should be evaluated in the differential diagnosis for pediatric patients presenting with symptoms of dry eyes, especially in cases without xerostomia or other systemic rheumatologic findings. Following a thorough history and examination, noninvasive imaging techniques can be utilized to assess for potential lacrimal gland agenesis and aid in confirming the diagnosis.

Quality Assessment of Radiomics Studies on Functional Outcomes After Acute Ischemic Stroke-A Systematic Review.

OBJECTIVE: Radiomics is a machine-learning method that extracts features from medical images. The objective of the present systematic review was to assess the quality of existing studies that use radiomics methods to predict functional outcomes in patients after acute ischemic stroke. METHODS: Studies using radiomics-extracted features to predict functional outcomes among patients with acute ischemic stroke using the modified Rankin Scale were included. PubMed, Scopus, Web of Science, and Embase were screened using the terms "radiomics" and "texture" in combination with "stroke." Quality scores were calculated based on Radiomics Quality Score, the IBSI (Image Biomarkers Standardization Initiative), and the QUADAS-2 (Quality Assessment of Diagnostic Accuracy Studies 2). RESULTS: Fourteen studies were included. The median total Radiomics Quality Score was 14.5 (13-16) out of 36. Domains 1, 5, and 6 on protocol quality and stability of imaging and segmentation, level of evidence, and use of open science and data, respectively, were poor. Median IBSI score was 2.5 (1-5) out of 6. Few studies included bias-field correction algorithms, isovoxel resampling, skull stripping, or gray-level discretization. Of 14 studies, none received +6 points, 1 received +5 points, 5 received +4 points, 1 study received +3 points, 5 received +2 points, 2 received +1 points, and none received 0 points. As per the QUADAS-2, 6/14 (42.9%) studies had a risk of bias concern and 0/14 (0%) had applicability concern. CONCLUSIONS: The quality of the included studies was low to moderate. With increasing use of radiomics, future studies should attempt to adhere to and report established radiomics quality guidelines.

Mechanical Thrombectomy for In-Hospital Onset Stroke: A Comparative Systematic Review and Meta-Analysis.

BACKGROUND AND PURPOSE: In-hospital onset stroke (IHOS) accounts for a significant proportion of large vessel occlusion acute ischemic strokes, leading to worse outcomes due to delays in evaluation and treatment. Limited data is available on the effectiveness of mechanical thrombectomy in IHOS patients. This study aims to assess the safety and efficacy of mechanical thrombectomy for patients with IHOS and compare the outcomes with those of community-onset strokes (COS). METHODS: We conducted a systematic review and meta-analysis following established guidelines, by searching PubMed, Scopus, Web of Science, and Embase databases up to April 11, 2023. Eligible studies reporting outcomes of interest were included, and relevant data was extracted and analyzed using Stata software version 17.0. RESULTS: In a meta-analysis of nine studies, comprising 540 cases of IHOS and 5,744 cases of COS, IHOS cases had a significantly lower rate of good functional outcomes on follow-up (35.46% vs. 40.74%, P<0.01) and a higher follow-up mortality rate (26.29% vs. 18.08%, P<0.01) compared to COS patients. Both groups had comparable successful recanalization rates (IHOS: 79.32% vs. COS: 81.44%, P=0.11), incidence rates of periprocedural complications (IHOS: 15.10%, COS: 12.96%, P=0.78), and symptomatic intracranial hemorrhage (IHOS: 6.24%, COS: 6.88%, P=0.67). It is worth noting that much of the observed effect size for mortality and good functional outcomes on follow-up was derived from only one and two studies, respectively. CONCLUSION: While the current literature suggests that mechanical thrombectomy is a safe and effective treatment for IHOS, further research is necessary to comprehensively evaluate its impact, particularly during follow-up.

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.

Comparative meta-analysis of endovascular strategies for intracranial dissecting aneurysms: Flow diverters versus stents with or without coiling.

BACKGROUND: Intracranial dissecting aneurysms present a challenging subset linked to considerable morbidity and mortality, necessitating effective therapeutic strategies to prevent complications. Traditional treatments face technical limitations, while emerging endovascular modalities like stent-assisted coiling, multiple stenting, and flow-diverting devices (FDDs) offer promise in reducing periprocedural risks and enhancing patient outcomes. The aim of this study is to compare the safety and efficacy outcomes of endovascular treatment for intracranial dissecting aneurysms using FDDs versus stents (with or without coiling). METHODS: A systematic review and meta-analysis were conducted following established guidelines. The search included PubMed, Scopus, Web of Science, and Embase databases up to July 30, 2023. Eligible studies reporting outcomes of interest in both FDD and stent-treated groups were included, and the data was extracted and analyzed using STATA software. RESULTS: Six studies were analyzed, involving 131 patients in the FDD group and 199 patients in the stent group. The pooled rates for favorable functional outcomes (86.8% vs. 86%), mortality (3.9% vs. 6%), adequate occlusion (79.7% vs. 86.3%), aneurysm recurrence (1.3% vs. 13.3%), in-stent stenosis/thrombosis (7% vs. 6.9%), ischemic events/infarctions (6.7% vs. 7.8%), retreatment (7% vs. 8.6%), and technical success (100% vs. 98.7%) were comparable in individuals treated with FDDs and stents (p > 0.05 in all cases). Additionally, complete occlusion rates were not significantly different between FDD (62.7%) and stent-treated patients (75.2%) (p = 0.06). However, after excluding one study in a leave-one-out analysis of the random effects meta-analysis, a significant difference in the pooled rates of this outcome was observed between the FDD (59.2%) and stent (75.2%) groups (p = 0.034). CONCLUSION: FDDs present a promising approach for the treatment of intracranial dissecting aneurysms, yielding outcomes that are roughly comparable to stent-based methods. However, the absence of randomized trials and data limitations highlight the need for further research to enhance treatment strategies.

How the elastase-induced rabbit aneurysm heals following flow diverter treatment: a histopathological study.

OBJECTIVE: Fibrin deposition is integral to thrombus formation and wound healing. The role of fibrin deposition and subsequent metabolism following flow diversion for aneurysm treatment remains poorly characterized. This study aimed to evaluate the role of fibrin in early thrombus organization after flow diverter treatment. METHODS: Thirty-five elastase-induced aneurysms were induced in New Zealand white rabbits and subjected to endoluminal flow diversion treatment. The device-bearing arteries were harvested at 1, 3, and 6 months postimplantation and processed for histopathological examination, including a modified picro-Mallory stain (Carstairs method) to visualize fibrin and platelets, immunohistochemical targeting of smooth muscle actin (SMA), and H&E staining for conventional morphological evaluation. Quantitative analysis of tissue components was carried out using the Orbit Image Analysis software. The samples were also assessed qualitatively to investigate the morphology and location of fibrin and other thrombus components within the intra-aneurysmal thrombi. Statistical analyses were conducted using R software version 4.3.1. RESULTS: Fibrin constituted 27.9% of the thrombus tissue within the aneurysm sac for aneurysms harvested at 1 month, and this rate was significantly lower in the 3-month group (10.2%, p = 0.018). The proportion of blood cells within the sac was also notably higher in the 1-month group compared with other time points. The primary tissue filling the dome at 1 month (14/15, 93%) was an unorganized thrombus primarily composed of fibrin, platelets, and red blood cells. Conversely, aneurysms harvested at 1 month had the lowest collagen level (25.6%). However, collagen became the dominant tissue component within the aneurysm sac, accounting for 71.8% of tissue in the 3-month group (p = 0.007). There were no differences observed among the examined components between the 3-month and 6-month groups. On qualitative analysis, collagen-producing SMA-positive myofibroblasts were located near or in between fibrin molecules. Healed aneurysms exhibited myofibroblasts, collagen, and a well-organized fibrin network on the aneurysm neck. In contrast, unhealed aneurysms displayed a poorly organized fibrin network with scattered myofibroblasts at the neck area. CONCLUSIONS: These findings indicate that fibrin plays a foundational role in the gradual occlusion of aneurysms after flow diverter treatment. Endovascular approaches that enhance fibrin accumulation could potentially improve aneurysm occlusion rates. Further research is needed to establish the precise role of fibrin in aneurysm occlusion.

Differences in outcome between left-sided and right-sided mechanical thrombectomy for acute ischemic stroke: A systematic review and meta-analysis.

BACKGROUND: Mechanical thrombectomy (MT) is a safe and effective treatment option for acute ischemic stroke due to large vessel occlusion. To investigate differences in outcomes between patients receiving left-sided and right-sided MT, we performed a systematic review and meta-analysis. METHODS: A systematic literature review was performed using Embase, PubMed, Scopus, and Web of Science databases. Additional literature was searched for manually. Studies reporting safety and efficacy metrics for MT were included. Data regarding the modified Rankin scale (mRS), thrombolysis in cerebral infarction (TICI), symptomatic intracranial hemorrhage (sICH), and 90-day mortality were included. A random-effects model was used to calculate pooled odds ratios (ORs), mean differences (MDs), and 95% confidence intervals (CIs). RESULTS: The literature search yielded 13 reports consisting of 19 studies ranging from 98 to 5590 patients. Patients presenting with left-sided stroke had a National Institutes of health stroke scale score 2.89 greater than patients presenting with right-sided stroke (MD = 2.89; 95% CI = 2.09-3.68; P-value < 0.001). There were no differences between left-sided and right-sided MT patients for mRS 0-2 (OR = 0.94; 95% CI = 0.85-1.04; P-value = 0.224), TICI 2b-3 (OR = 1.05; 95% CI = 0.88-1.25; P-value = 0.598), sICH (OR = 0.83; 95% CI = 0.61-1.14; P-value = 0.255), or 90-day mortality (OR = 1.06; 95% CI = 0.84-1.33; P-value = 0.610). CONCLUSIONS: There does not appear to be a difference in outcomes for patients undergoing left-sided or right-sided thrombectomy.

How Flow Diverter Selection Can Affect the Flow Changes within a Jailed Ophthalmic Artery: A Computational Fluid Dynamics Study.

Introduction Flow diverter (FD) stents are widely used to treat giant aneurysms by reducing blood flow into the aneurysm sac. However, choosing the optimal FD for a patient can be challenging when a nearby artery, such as the ophthalmic artery (OA), is jailed by the FD placement. This study compares the impact of two FD stents with different effective metal surface area (EMSA) values on OA occlusion. Materials and Methods A numerical model of a 59-year-old female patient with a giant aneurysm in the left internal carotid artery and a jailed OA was created based on clinical data. Two FD stents, FRED4017 and FRED4518, with different EMSA values at the aneurysm neck and OA inlet, were virtually deployed in the model. Blood flow and occlusion amount in the OA were simulated and compared between the two FD stents. Results FRED4017 had higher EMSA values than FRED4518 at the aneurysm neck (35% vs. 24.6%) and lower EMSA values at the OA inlet (15% vs. 21.2%). FRED4017 caused more occlusion in the OA than FRED4518 (40% vs. 28%), indicating a higher risk of ocular ischemic syndrome. Conclusion The EMSA value of FD stents affects the blood flow and occlusion amount in the jailed OA. Therefore, selecting an FD stent with a low EMSA value at the OA inlet may be beneficial for patients with a nearby jailed artery at the aneurysm neck.

Cyclic Aspiration in Mechanical Thrombectomy: Influencing Factors and Experimental Validation.

BACKGROUND AND PURPOSE: Mechanical thrombectomy is a fundamental intervention for acute ischemic stroke treatment. While conventional techniques are effective, cyclic aspiration (CyA) shows potential for better recanalization rates. We aim to investigate factors affecting CyA and compare them with static aspiration (StA). MATERIALS AND METHODS: StA setup consisted of an aspiration pump connected to pressure transducer. CyA was tested with 5 subsequent iterations: single solenoid valve with air plus saline (i1) or saline alone (i2) as aspiration medium; 2 solenoid valves with air plus saline (i3) as aspiration medium; complete air removal and saline feeding (i4); and pressurized saline feeding (i5). To assess the efficacy of clot ingestion, the pressure transducer was replaced with a distal aspiration catheter. Moderately stiff clot analogs (15 mm) were used to investigate the ingestion quantified as clot relative weight loss. Additionally, the aspiration flow rate was assessed for each setup. RESULTS: With CyA i1, the amplitude of the achieved negative pressure waves declined with increasing frequencies but progressively increased with each subsequent iteration, achieving a maximum amplitude of 81 kPa for i5 at 1 Hz. Relative clot weight loss was significantly higher with i5 at 5 Hz than with StA (100% versus 37.8%; P = .05). Aspiration flow rate was lower with CyA than with StA (i5 at 5 Hz: 199.8 mL/min versus StA: 311 mL/min; P < .01). CONCLUSIONS: CyA with the appropriate setup may represent an encouraging innovation in mechanical thrombectomy, offering a promising pathway for improving efficacy in clot ingestion and recanalization. The observed benefits warrant confirmation in a clinical setting.

The Effect of the COVID-19 Pandemic on Academic Research Gender Disparities in Radiology.

RATIONALE AND OBJECTIVES: Gender disparities have long existed in radiology. The COVID-19 pandemic disrupted research activities worldwide and have impacted gender disparities across medical specialties. This study investigates the effect of the COVID-19 pandemic on gender disparities in radiology academic authorship. MATERIALS AND METHODS: A retrospective observational study was conducted using data from 110 843 global and 23 977 US radiology articles. The gender of authors was determined using an automated gender inference tool. Descriptive statistics were applied to explore authorship changes overall globally, in the US as well as across countries and states. RESULTS: Female first-authorship increased globally from 16.9% to 17.6% (p < 0.001), and in the US, from 19.0% to 19.6% (p = 0.19) in the peri-COVID period. The combined female percentage increased from 19.7% to 20.0% globally (p = 0.021), and from 20.2% to 21.1% in the US (p = 0.006). Country-level analysis revealed significant increases in female authorship in Colombia, Denmark, Egypt, France, India, and Japan, while New Zealand demonstrated a decrease in female authorship. In the US, Florida, Indiana, Louisiana, Massachusetts, and Ohio experienced increases in female authorship, whereas South Carolina demonstrated a decrease in female authorship. CONCLUSION: In contrast with other medical fields, the study demonstrates that radiology experienced a slight increase in female authorship in radiology research globally and in the US during the COVID period. While the pandemic may have influenced these findings, further research is needed to establish regional causal relationships and identify best practices for promoting gender equity in radiology research.

Effects of intravenous thrombolysis on stent retriever and aspiration thrombectomy outcomes: a systematic review and meta-analysis of the randomized controlled trials.

BACKGROUND: Risks and benefits of intravenous thrombolysis (IVT) in patients undergoing mechanical thrombectomy (MT) have been a topic of interest. However, IVT's specific effects on stent retriever (SR) and aspiration thrombectomy (ASP) outcomes remain largely unexplored. In this meta-analysis, we aimed to investigate the effects of IVT on SR and ASP thrombectomy outcomes. METHODS: In accordance with PRISMA guidelines, a systematic literature review was conducted using Medline, Embase, Scopus, Web of Science, and Cochrane Center of Clinical Trials databases. Outcomes of interest included successful recanalization (modified Thrombolysis In Cerebral Infarction (mTICI) ≥2b), modified first pass efficacy (mFPE), functional independence (modified Rankin Scale (mRS) ≤2), symptomatic intracranial hemorrhage (sICH), and embolization to new territories (ENT). RESULTS: Four randomized controlled trials with 1176 patients were included. SR and ASP resulted in similar mTICI ≥2b, mFPE, and mRS 0-2 rates in patients with and without IVT administration. SR without IVT was associated with a significantly lower rate of mFPE compared with the SR+IVT (RR 0.85, 95% CI 0.74 to 0.97). Furthermore, ASP without IVT resulted in a lower rate of mRS 0-2 than the ASP+IVT with a strong trend towards significance (RR 0.78, 95% CI 0.60 to 1.01). Finally, bridging therapy did not increase sICH and ENT rates after ASP or SR thrombectomy. CONCLUSIONS: Our findings suggest that SR and ASP thrombectomy have comparable safety and efficacy profiles, regardless of prior IVT administration. Additionally, our results indicate that the addition of IVT may improve certain efficacy outcomes based on the employed first-line MT technique.