Deep venous drainage (DVD) is considered a negative prognostic factor in AVM surgery, yet its effect on postoperative functional decline remains incompletely defined. This study evaluates whether DVD predicts worsened functional status after surgical resection of Spetzler-Martin Grade II-III AVMs. This retrospective multicenter study analyzed 129 patients with Spetzler-Martin Grade II-III AVMs across nine centers in North America and Europe who underwent primary surgical resection. We excluded cases with prior endovascular or stereotactic interventions. The primary outcome measured was poor functional status, defined as modified Rankin Scale (mRS) score 3–6 at last follow up. Among 129 patients with Spetzler-Martin Grade II-III AVMs, 38 (29.5

BACKGROUND:The role of flow diversion for middle cerebral artery (MCA) aneurysms remains controversial due to frequent involvement of side branches and bifurcations. While outcomes have been reported in cohort studies and case series, the safety and efficacy of this approach remain uncertain. PURPOSE:To evaluate angiographic and clinical outcomes following flow diversion for MCA aneurysms. DATA SOURCES:A systematic literature search was performed across databases in accordance with PRISMA guidelines to identify studies reporting on flow-diverter treatment of MCA aneurysms. STUDY SELECTION:Studies including ≥3 patients treated with flow-diverter devices and reporting angiographic or clinical outcomes were eligible for inclusion. Thirty-three studies encompassing 1,036 MCA aneurysms met criteria, representing the largest cohort to date. DATA ANALYSIS:Data on study design, patient and aneurysm characteristics, treatment details, and angiographic and clinical outcomes were extracted. Pooled estimates with 95% confidence intervals (CIs) were calculated using a random-effects model, with subgroup analyses by aneurysm location and device type. DATA SYNTHESIS:The pooled complete or near-complete occlusion rate was 71% at a mean follow-up of 15 months, with no significant differences across MCA segments (66% proximal, 69% bifurcation, 70% distal) or across device types. The overall complication rate was 13%, predominantly thromboembolic, with a 1% procedural mortality. Functional independence (mRS 0-2) was achieved in 90% of patients. LIMITATIONS:Included studies were predominantly retrospective cohort series and case series with heterogeneity in device type, antiplatelet regimens, follow-up duration, and outcome definitions. Publication bias and underreporting of complications cannot be excluded. CONCLUSIONS:Flow diversion for MCA aneurysms achieves approximately 71% complete or near-complete occlusion with a 13% complication rate. These findings may support its consideration in carefully selected cases, though the retrospective evidence base warrants cautious interpretation.

Middle meningeal artery embolization (MMAE) plus surgical evacuation is increasingly used for chronic subdural hematoma (cSDH), but predictors of length of stay (LOS) and outcomes associated with early discharge remain unclear. We performed a multicenter MESH Registry study (2019–2024) of patients undergoing MMAE and surgical evacuation for symptomatic cSDH. Short-stay discharge was defined as LOS ≤4 days. Predictors were identified using multivariable logistic regression. The 90-day composite adverse event was defined as cSDH recurrence requiring intervention, reintervention (repeat MMAE or surgical evacuation), or 30-day all-cause readmission. Safety was assessed using adjusted logistic regression, generalized estimating equations (GEE), inverse probability of treatment weighting (IPTW), and multiple imputation by chained equations (MICE). Among 647 patients (mean age 72.6 years; 74.0

Middle meningeal artery embolization (MMAE) has emerged as a treatment for chronic subdural hematoma (cSDH), but comprehensive real-world safety data remain limited. We performed a multicenter retrospective analysis of 1781 consecutive patients undergoing MMAE for cSDH (2019–2025). The primary outcome was any procedure-related complication within 30 days. Inverse probability of treatment weighting (IPTW) assessed the association between technical success and complications, adjusting for demographic, clinical, and procedural confounders. Mean age was 72.8 ± 12.4 years; 68.1

Background: Flow diversion for anterior communicating artery (ACom) aneurysms remains technically challenging due to small vessel caliber, bifurcation anatomy, and perforator involvement. Although case series suggest feasibility, the overall efficacy and safety of flow-diverter (FD) treatment for ACom aneurysms are not well established. Purpose: To synthesize the available evidence on occlusion rates, complications, clinical outcomes, and retreatment following FD treatment for ACom aneurysms. Materials and methods: Following PRISMA guidelines, databases (PubMed/MEDLINE, Embase, Scopus, Web of Science, Cochrane Library) were searched for studies published January 2010–September 2025 including ≥ 3 patients treated with FD devices reporting angiographic or clinical outcomes. Extracted data encompassed study characteristics, demographics, aneurysm morphology, treatment details, occlusion, complications, and modified Rankin Scale (mRS). Pooled proportions with 95

BACKGROUND:Endovascular thrombectomy (EVT) for distal and medium vessel occlusion stroke remains uncertain. We aimed to develop a medium and distal mechanical thrombectomy score integrating clinical need and procedural risk to guide patient selection. METHODS:This retrospective cohort analysis used an international distal and medium vessel occlusion stroke registry spanning the study period of 2017 to 2023. Patients with acute distal and medium vessel occlusion stroke who received medical management (MM) or EVT across 37 stroke centers were included, and those with baseline modified Rankin Scale score of ≥3 or those with missing covariable data were excluded. Multivariable logistic regression identified predictors of poor functional outcome (modified Rankin Scale score >2 at 90 days) in the MM cohort and predictors of EVT failure/complications in the EVT cohort. Predictors of poor outcome on MM were assigned positive weights (clinical need); predictors of EVT failure/harm were assigned negative weights (procedural risk). The medium and distal mechanical thrombectomy score summed these weighted points. Interaction analysis assessed the heterogeneity of EVT effect by score. RESULTS:A total of 1217 patients were identified, and 1007 were included (EVT: 822, MM: 185; median age 73 years; 41% female). Higher National Institutes of Health Stroke Scale score (+1 per point) and lack of intravenous thrombolysis (+7) predicted poor MM outcomes. In the EVT cohort, older age (-1 per 15 years above 25), absence of hypertension (-2), and absence of atrial fibrillation (-2) predicted failure/complications. The medium and distal mechanical thrombectomy score (range -8 to 49) significantly modified EVT effect versus MM (Pinteraction=0.048). In high-score patients (≥15; n=293), EVT yielded a better 90-day modified Rankin Scale score than MM (median, 3 versus 4; P=0.009). Conversely, in low-score patients (<15; n=710), EVT yielded a worse modified Rankin Scale score (median, 2 versus 1; P=0.014). CONCLUSIONS:The medium and distal mechanical thrombectomy score is a pragmatic tool that identifies patients with distal and medium vessel occlusion most likely to benefit from EVT while minimizing risk, supporting patient-centered decisions and future trial design.

BACKGROUND:The prognostic significance of posterior reversible encephalopathy syndrome (PRES) among patients with reversible cerebral vasoconstriction syndrome (RCVS) is uncertain. METHODS:We performed a retrospective cohort study using TriNetX database. Adults with an index diagnosis of RCVS were stratified by concomitant PRES. Patients with prior stroke, hemorrhage, or cerebral edema were excluded. Propensity-score matching (1:1) balanced covariates. Primary outcomes at 1 and 5 years were ischemic stroke, subarachnoid hemorrhage, and a composite of these events; secondary outcomes included inpatient readmissions. Hazard ratios (HRs) with 95% confidence intervals (CIs) were estimated. RESULTS:Among 152 patients with RCVS+PRES and 3233 with RCVS alone, 150 matched pairs were generated (standardized differences <0.10). At 1 year, ischemic stroke occurred more frequently in the RCVS+PRES group compared with the RCVS-alone group (37.1% vs. 16.67%; HR, 2.50; 95% CI, 1.528-4.093), and inpatient readmissions were higher (54.11% vs. 25.74%; HR, 2.596; 95% CI, 1.731-3.892). Rates of subarachnoid hemorrhage were not significantly different between groups. At 5 years, RCVS+PRES remained associated with higher risks of ischemic stroke, inpatient readmissions, and the composite outcome of stroke or subarachnoid hemorrhage. CONCLUSIONS:Among patients with RCVS, the presence of concomitant PRES identifies a higher-risk subgroup characterized by increased rates of ischemic stroke and hospital readmission at 1 year, with persistent cerebrovascular risk over 5 years. These findings suggest that PRES may represent a marker of more severe cerebrovascular dysregulation requiring closer monitoring.

INTRODUCTION:Asymptomatic moyamoya angiopathy (MMA) is increasingly detected through noninvasive imaging; however, its optimal management remains controversial. This multicenter retrospective cohort study compared outcomes in asymptomatic versus symptomatic MMA patients undergoing surgical revascularization. PATIENTS AND METHODS:A total of 475 patients treated with bypass surgery across multiple academic centers were included, with 56 (11.8%) classified as asymptomatic and 419 (88.2%) as symptomatic. Baseline demographics, surgical characteristics, and outcomes-including perioperative stroke, intraoperative complications, and follow-up stroke events-were collected. Asymptomatic MMA was defined as the absence of any prior ischemic or hemorrhagic stroke, seizures, or other neurological symptoms at the time of diagnosis. Both unadjusted analyses and propensity score weighting using inverse probability of treatment weighting (IPTW) were performed to adjust for potential confounders. RESULTS:In the unadjusted analysis, asymptomatic patients had significantly lower rates of all perioperative strokes (1.7% vs 11.4%; p = 0.05) and intraoperative complications (1.7% vs 11.2%; p = 0.05) compared to symptomatic patients. Additionally, follow-up stroke rates were lower in the asymptomatic group (1.7% vs 11.2%; p = 0.05). After IPTW adjustment, the reduction in intraoperative complications (OR: 0.08, 95% CI: 0.01-0.64; p = 0.01) and follow-up stroke rates (OR: 0.12, 95% CI: 0.01-0.91; p = 0.04) persisted, while differences in overall perioperative stroke were not statistically significant. CONCLUSION:Bypass surgery in selected asymptomatic MMA patients is associated with reduced intraoperative complications, and fewer follow-up stroke rates. These findings support the careful consideration of surgical intervention in asymptomatic patients, emphasizing the importance of patient selection for optimal outcomes.

The Woven EndoBridge (WEB) device is a prevalent treatment for intracranial aneurysms. While many studies have assessed the obliteration rate post-WEB embolization, few have focused on long-term outcomes in partially thrombosed aneurysms. To assess whether partially thrombosed aneurysms are at higher risk of recurrence or retreatment following WEB embolization compared with non-thrombosed aneurysms. We evaluated data from 22 academic institutions, focusing on previously untreated cerebral aneurysms treated with the WEB device. Logistic regression was utilized to analyze factors predicting long-term aneurysm obliteration and retreatment necessity. Among 1303 patients, 26 presented with a partially thrombosed aneurysm. In the partially thrombosed group, the mean aneurysm maximal diameter was 10.7±4 mm with a neck ratio of 1.99±1.19 mm, larger than in the control group where the mean aneurysm maximal diameter was 6.81±2.37 mm with a neck ratio of 1.64±0.51 mm (P<0.001 for both maximal diameter and neck ratio). At the final follow-up, partially thrombosed aneurysms treated by the WEB device had a 38.5% retreatment rate, compared with 7.0% for non-thrombosed aneurysms (P<0.001). Among partially thrombosed aneurysms, the Raymond-Roy type IIIa/b occlusion rate was higher (38.5% vs 9.9%, P<0.001). On multivariate analysis, partially thrombosed aneurysms compared with non-thrombosed aneurysms had an increased rate of retreatment (OR 3.64, 95% CI 1.28 to 10.1). Partially thrombosed aneurysms are associated with a poorer occlusion rate and a higher rate of retreatment following WEB embolization. For partially thrombosed aneurysms, the WEB device appears suboptimal as a first-line treatment, and therefore alternative techniques should be prioritized.

Although the Woven EndoBridge (WEB) device is increasingly used for the treatment of wide-neck intracranial aneurysms, including in the acute rupture setting, comparative evidence assessing the impact of rupture status remains limited. This study compared angiographic, safety, and clinical outcomes between ruptured and unruptured intracranial aneurysms treated with WEB. We conducted a retrospective analysis of prospectively collected data from the multicenter cohort registry WorldWideWEB, including consecutive adult patients with intracranial aneurysms treated with the WEB. Patients were stratified into groups of ruptured and unruptured aneurysms. Propensity score matching was used to balance baseline characteristics between both groups. Retreatment rate was the primary outcome. Secondary outcomes included mRS, safety events (thromboembolic complications) and angiographic outcomes (periprocedurally and last follow-up). Among 1,220 patients, 342 (28.0

OBJECTIVE:The objective was to evaluate the trajectories of hematoma resolution and functional improvement after middle meningeal artery embolization (MMAE) for chronic subdural hematoma (cSDH), model the temporal pattern of cSDH resolution, and identify factors associated with favorable outcomes. METHODS:This real-world multicenter retrospective study included cSDH patients treated with MMAE at 24 centers between 2019 and 2024. Hematoma thickness was measured at baseline and at follow-up intervals (1-4 weeks, 1-3 months, 3-6 months, 6-12 months, and > 12 months after embolization). Resolution patterns were modeled using exponential decay functions. Modified Rankin Scale (mRS) scores assessed functional outcomes. Good functional outcome was defined as mRS score ≤ 2. Resolution patterns were modeled using exponential decay functions to estimate time to 50% and 80% reduction. Patients were categorized as complete resolution (≥ 99%) or by quartile of the remaining distribution (substantial [73%-98%], moderate [53%-73%], partial [27%-53%], minimal [< 27%]). The primary outcome was good functional status (mRS score ≤ 2). RESULTS:The authors analyzed a total of 1781 patients with 2295 cSDHs who underwent MMAE. The mean ± SD age was 72.8 ± 12.4 years and 68.1% of patients were male. The initial mean hematoma thickness was 15.31 ± 6.53 mm, decreasing to 5.24 ± 5.91 mm at final follow-up (mean reduction 64.3% ± 42.1%). Resolution followed an exponential decay pattern, with an estimated time to 50% reduction of 1.8 months and to 80% reduction of 8.9 months. Complete resolution occurred in 1031 of 2224 patients (46.4%) with complete follow-up. The median (IQR) mRS score improved from 1 (0-3) at baseline to 0 (0-2) at > 12 months. Good functional outcomes were more common in patients with complete versus minimal resolution (68.9% vs 35.0%, p < 0.001). Achieving ≥ 73% resolution within 90 days was associated with better outcomes (good outcome in 76.9% of those with ≥ 73% resolution vs 67.3% in those without, p < 0.001). Neurological deterioration was the strongest predictor of lack of good outcome (23.7% in patients with neurological deterioration vs 82.4% without, p < 0.001). CONCLUSIONS:After MMAE for cSDH, reduction in hematoma thickness follows a predictable exponential decay pattern. Greater extent (≥ 80%) and faster timing (within 90 days) of resolution are valuable prognostic indicators. Functional outcomes improve progressively through 6-12 months after the procedure. The relationship between resolution extent and functional outcomes provides quantitative benchmarks for evaluating treatment response.

BACKGROUND:The Woven EndoBridge (WEB) device has emerged as a promising option for treating wide-neck bifurcation aneurysms. This multicenter study aimed to evaluate the impact of postoperative aspirin (ASA) use on clinical and angiographic outcomes in patients treated with the WEB device. METHODS:We conducted a retrospective multicenter study across 10 academic institutions, analyzing patients with ruptured or unruptured intracranial aneurysms treated with the WEB device. RESULTS:A total of 225 patients were included, with 163 (72.4%) receiving postoperative ASA and 62 (27.6%) in the no antiplatelet (No AP) group. Before propensity score matching (PSM), the ASA group demonstrated significantly higher rates of excellent functional outcomes (mRS 0-1: 84% vs. 70%, p = 0.031) and lower mortality (3.3% vs. 13%, p = 0.014). Retreatment rates were also significantly lower in the ASA group (8.6% vs. 23%, p = 0.005). After PSM, 120 patients remained (74 ASA, 46 No AP). Retreatment rates remained significantly lower in the ASA group (5.4% vs. 24%, p = 0.003), whereas the other outcomes did not reach statistical significance after matching. CONCLUSION:Postoperative aspirin use following WEB device treatment for intracranial aneurysms was associated with significantly lower retreatment rates, without compromising functional outcomes or mortality rates. These findings support the potential role of aspirin in enhancing aneurysm stability. Further prospective studies are needed to confirm.

Data on the use of Woven EndoBridge (WEB) devices in the treatment of narrow-neck intracranial aneurysms (NNA) are limited. We compared the efficacy and safety of single-layer (SL) and single-layer spherical (SLS) WEB devices in treating NNA. We conducted a multicenter retrospective analysis of adult patients with NNA (neck ≤ 4 mm and width-to-neck ratio ≥ 2) treated with SL or SLS WEB devices between January 2011 and December 2022. Patients with fusiform or blister aneurysms, adjunctive treatments, or devices other than SL or SLS were excluded. Propensity score matching was used to adjust for confounding variables. Outcomes included procedural complications, angiographic occlusion rates using the Raymond Roy classification, major device compaction, need for retreatment, and functional outcomes assessed by the modified Rankin Scale (mRS). After matching, resulting in 101 patients in each group, baseline characteristics were well-balanced. Thromboembolic complications occurred in 2.0

BACKGROUND:Moyamoya syndrome (MMS) associated with sickle cell disease (SCD) is a severe vasculopathy that significantly increases stroke risk. While cerebral revascularization is increasingly considered in this population, concerns about perioperative safety and long-term outcomes have limited its use in clinical practice. METHODS:We conducted a multicenter, retrospective cohort study of 553 patients with MMS who underwent surgical revascularization across 13 centers. Patients were grouped by SCD status (SCD-MMS vs. moyamoya disease (MMD)). Primary outcomes included perioperative stroke, perioperative complications, and functional status at discharge. Secondary outcomes included length of stay, and follow-up stroke. RESULTS:Of 553 patients, 32 (5.8%) had SCD. There were no significant differences in overall perioperative stroke (OR 1.05, 95% CI 0.19 to 5.54), symptomatic perioperative stroke (OR 0.94, 95% CI 0.09 to 8.94), perioperative complications (OR 1.66, 95% CI 0.47 to 5.86), or follow-up stroke (OR 0.88, 95% CI 0.17 to 4.55). Functional outcomes at discharge were similarly favorable in both groups (mRS 0-1: OR 0.84, 95% CI 0.29 to 2.40). SCD was associated with a longer hospital stay (beta 2.78 days, 95% CI 0.60 to 4.96). CONCLUSION:Surgical revascularization for MMS in patients with SCD does not confer additional procedural risk and yields outcomes comparable to those of patients without SCD. These findings support the role of bypass surgery as a viable treatment option in this high-risk population.

BACKGROUND AND PURPOSE:Chronic subdural hematoma (cSDH) affects approximately 20 per 100,000 individuals annually, with surgical recurrence rates of 10-20%. Middle meningeal artery embolization (MMAE) has emerged as a promising minimally invasive treatment, but the optimal timing remains unclear. We evaluated the association between MMAE timing and radiological and functional outcomes in cSDH. METHODS:We conducted a retrospective multicenter international cohort study across 33 centres, including patients who underwent MMAE for cSDH between January 2018 and December 2024. Patients were stratified by timing from diagnosis: Q1 (≤1 day), Q2 (2 days), Q3 (3-6 days), and Q4 (>6 days). The primary composite endpoint required radiological success (hematoma thickness <5 mm at 1-3 months), absence of emergency surgical evacuation, and either functional improvement or good functional outcome (modified Rankin Scale 0-2). Propensity score matching compared Q1 and Q4. RESULTS:Of 1,781 patients screened, 908 met inclusion criteria. Mean age was 73.7 ± 12.2 years, and 70.9% were female. Early embolization (Q1) achieved the primary composite endpoint more frequently than delayed embolization (Q4), with concordant improvements in radiological and functional components and no difference in rescue surgery. Good functional outcome was achieved in 76.0% of Q1 patients versus 63.8% in Q4 (absolute difference, 12.2%; P=.003; number needed to treat approximately 8). Hospital length of stay was 21.0 days shorter in Q1 versus Q4 (P<.001), partly attributable to the timing definition. In 174 propensity score-matched pairs, early embolization was associated with higher odds of achieving the primary endpoint (odds ratio, 6.41; 95% confidence interval, 3.29-12.48; P<.001), with pronounced benefit among patients receiving antithrombotic therapy (odds ratio, 8.06; 95% confidence interval, 3.65-17.80). CONCLUSIONS:Early MMAE (≤1 day from diagnosis) was overall associated with better outcomes compared with delayed intervention, particularly among patients receiving antithrombotic therapy. Prospective confirmation is warranted.

INTRODUCTION:Patient and arteriovenous malformation (AVM) characteristics that portend success after treatment for low-grade brain AVMs remain unknown. PATIENTS AND METHODS:We utilised the MISTA multicentre registry to identify patients with Spetzler-Martin (SM) grade I or II AVMs treated with stand-alone curative-intent intervention (resection, stereotactic radiosurgery [SRS] or endovascular embolisation). Bivariate and multivariable analyses were performed to identify patient and AVM characteristics predictive of complete obliteration or favourable outcome (complete obliteration without new permanent deficit or post-treatment haemorrhage). RESULTS:A total of 522 patients were included (292 microsurgery, 152 SRS, 78 embolisation). Complete obliteration rates differed between microsurgery (95.9%), SRS (75.0%) and embolisation (71.8%) (P < .001); among patients classified as cured, digital subtraction angiography (DSA) confirmed obliteration in 96.1%, 75.9% and 52.4%, respectively. Favourable outcome was achieved in 89.4%, 64.5% and 67.9% (P < .001). In adjusted models for obliteration, elderly age (odds ratio [OR] 0.49, P = .022), larger nidus (OR 0.64, P = .005) and compacted morphology (OR 1.93, P = .019) were independent predictors overall; paediatric age predicted incomplete obliteration after microsurgery (OR 0.05, P = .045), and elderly age (OR 0.19, P = .001) and larger nidus (OR 0.59, P = .015) after SRS. For favourable outcome, SM grade II overall (adjusted OR [aOR] 0.58, P = .031) and elderly age after SRS (aOR 0.31, P = .019) were independent negative predictors. DISCUSSION:Low-grade AVMs showed high rates of complete obliteration, though DSA-confirmed rates were substantially lower after embolisation, underscoring the importance of angiographic confirmation. CONCLUSION:The predictors identified in this study may help guide management when 2 or 3 of the primary treatment options carry clinical equipoise.

Sex-related differences in outcomes after mechanical thrombectomy (MT) for distal medium vessel occlusion (DMVO) stroke remain uncertain. While unadjusted differences have been reported in stroke populations, it is unclear whether biological sex independently influences outcomes after accounting for major prognostic factors. We performed a retrospective, multicenter analysis of the MAD-MT registry. Patients with acute DMVO who underwent MT were included. Propensity score matching (PSM) was employed. The primary outcome was functional independence (modified Rankin Scale [mRS] score 0–2) at 90 days. Secondary outcomes included excellent outcome (mRS 0–1), day 1 NIHSS shift, and reperfusion success. Safety outcomes included mortality and symptomatic intracerebral hemorrhage. Before matching, 1147 females and 1062 males were included. After 1:1 PSM (748 patients in each group), the groups were balanced in baseline characteristics. The median age was 75 years in both groups. At 90 days, 51

Optimal treatment for acute ischemic stroke due to distal medium-vessel occlusion (DMVO) in the middle cerebral artery (MCA) remains uncertain. While mechanical thrombectomy (MT) may pose higher risks in DMVO, intra-arterial thrombolysis (IAT)—with or without intravenous thrombolysis (IVT)—could be a safer alternative. To compare functional outcomes and safety profiles of IAT versus MT in acute ischemic stroke caused by MCA DMVO (M2–M4 segments). We performed a retrospective, propensity score-matched study across 37 centers (Asia, Europe, North America) using the MAD-MT registry. Patients with MCA DMVO (M2–M4) treated with IAT or MT (with/without IVT) were included. Propensity score matching adjusted for confounders. The primary outcome was excellent functional outcome (modified Rankin Scale [mRS] 0–1 at 90 days). After matching, 184 patients were analyzed (19 IAT, 165 MT). Baseline characteristics were balanced. At 90 days, excellent functional outcomes occurred in 38

Small Woven EndoBridge (WEB) devices (≤ 4.5 mm) for the intracranial aneurysm treatment are technically challenging to deploy, with limited efficacy and safety data. This study compared functional, angiographic, and safety outcomes of small WEBs with large (> 4.5 mm) and very large (> 7.5 mm) WEBs. The WorldWideWEB consortium is a retrospective, multicenter collaboration across 30 international institutions including adults with intracranial aneurysms treated with WEB. Patients were stratified into small (≤ 4.5 mm) and large (> 4.5 mm) groups; a subanalysis compared small with very large (> 7.5 mm) devices. Primary outcome was retreatment rate. Secondary outcomes included modified Rankin Scale (mRS), angiographic outcomes periprocedurally and last follow-up (FU), and safety events (intracranial hemorrhage (ICH) and thromboembolic complications (TECs)). Among 1473 patients, 229 (15.5

Intracranial aneurysms (IAs) are the most common cause of non-traumatic subarachnoid hemorrhage (SAH). Although multiple risk factors have been identified—including female sex and tobacco exposure—smoking remains a well-established and modifiable driver of aneurysmal rupture; however, contemporary, women-focused, nationally representative estimates of rupture risk and care patterns using balanced comparisons and neurosurgically relevant inpatient outcomes derived from large, adjusted cohorts using balanced comparisons remain limited. The Healthcare Cost and Utilization Project (HCUP) National Inpatient Sample (NIS) was queried to identify female patients diagnosed with IAs between January 1, 2003, and December 31, 2020. The primary focus was to assess association with ruptured presentation at admission. A 1:1 matching was used to compare outcomes between female smokers and nonsmokers. The K-nearest neighbor method was employed with the Mann–Kendall test to analyze the data trends. A Random Forest model was developed to classify ruptured presentation at admission, predict the rupture risk and to quantify feature contributions through an association plot and feature importance plot leveraging SHAP (Shapley Additive Explanations) values. All analyses were conducted using R and Python software. Using the HCUP National Inpatient Sample (NIS), a nationwide real-world inpatient database, we identified 32,530 hospitalized women with intracranial aneurysm diagnoses. Of the 32,530 patients identified, 64