Faculty Bibliography

BACKGROUND: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. METHODS: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). RESULTS:Among 647 patients (mean age 72.6 years; 74.0% male), 156 (24.1%) had short-stay discharge. Median LOS was 8 days (IQR 5-15). Older age (aOR 0.76 per 10 years; 95% CI 0.62-0.93; P = 0.008), higher baseline modified Rankin Scale score (aOR 0.79 per point; 95% CI 0.67-0.94; P = 0.007), and greater midline shift (aOR 0.90 per mm; 95% CI 0.85-0.96; P = 0.001) were independently associated with lower odds of short-stay discharge. C‑statistic was 0.683. The 90-day composite event rate was 17.1% in short-stay versus 23.7% in long-stay patients. Short-stay discharge was not significantly associated with the composite outcome on adjusted analysis (aOR 0.56; 95% CI 0.30-1.07; P = 0.08), GEE (aOR 0.61; 95% CI 0.33-1.12; P = 0.11), or MICE (aOR 0.74; 95% CI 0.44-1.25; P = 0.26). IPTW showed a discordant association (OR 0.47; 95% CI 0.24-0.92; P = 0.03). CONCLUSIONS:Older age, worse baseline function, and midline shift were associated with longer hospitalization. Short-stay discharge was not associated with a statistically significant increase in adverse-event rates; however, the study was not powered to establish non-inferiority or safety equivalence, and clinically meaningful differences cannot be excluded.

BACKGROUND/OBJECTIVE/OBJECTIVE:Perimesencephalic subarachnoid haemorrhage (pmSAH) has traditionally been considered benign and of venous origin. However, advanced imaging increasingly identifies basilar artery perforator aneurysms (BAPAs) as a subset of cases historically labelled as non-aneurysmal, atraumatic (NAA) pmSAH. The objective was to compare clinical characteristics and outcomes of patients with NAA, BAPA and ruptured posterior circulation aneurysms (r-pc-AN), assessing the impact of pmSAH aetiology on patient outcomes. METHODS:This retrospective, multicentre, observational cohort study included BAPA cases from the international PERForator Aneurysm registry (2013-2025, 60 centres, 19 countries). Comparison cohorts were from a single high-volume tertiary care centre (2004-2025). The study included 444 patients (n=167 NAA, n=157 BAPA, n=120 r-pc-AN). Excellent outcome was defined as a modified Rankin Scale score of 0-1 at 3-6 months. RESULTS:Excellent outcomes were achieved in 137/167 (82%) of NAA, 96/140 (69%) of BAPA and 56/102 (55%) of r-pc-AN cohorts (p<0.001). Mortality rates were 1% (NAA), 11% (BAPA) and 18% (r-pc-AN). cCompared with BAPA, NAA patients had significantly higher odds of excellent outcome (adjusted OR, aOR 2.0, 95% CI 1.2 to 3.4, p=0.01), while r-pc-AN were associated with significantly lower odds of excellent outcome (aOR 0.5, 95% CI 0.3 to 0.9, p=0.01). Hydrocephalus and external ventricular drain rates were highest in r-pc-AN (83% and 87%), followed by BAPA (48% and 44%) and NAA (28% and 16%) (p<0.001). CONCLUSIONS:While pmSAH has been considered benign, our findings challenge this assumption. Patients with BAPA-related pmSAH demonstrated significantly worse outcomes than NAA but better outcomes than r-pc-AN. Further research is needed to distinguish BAPA-pmSAH from NAA-related pmSAH and to establish diagnostic and therapeutic guidelines. TRIAL REGISTRATION NUMBER/BACKGROUND:NCT06189014.

BACKGROUND AND PURPOSE/OBJECTIVE: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.

BACKGROUND:Anatomical variants of the anterior cerebral artery (ACA) may increase technical complexity during endovascular treatment of distal ACA aneurysms (DACA). However, their impact on treatment outcomes remains unclear. This study evaluated whether ACA variants influence angiographic and clinical outcomes following endovascular treatment. METHODS:A retrospective multicenter analysis was conducted using data from the CRETA Registry, including patients with ruptured and unruptured DACA treated endovascularly. Patients were grouped according to ACA anatomy (variant vs. conventional). Outcomes were compared after propensity score matching (PSM) to adjust for confounders including age, aneurysm rupture status, dome-to-neck ratio, branch origin, and treatment type. The primary outcome was aneurysm occlusion at last follow-up based on the Raymond-Roy classification. Secondary outcomes included ischemic and hemorrhagic complications, vasospasm, and clinical outcome measured by the modified Rankin Scale (mRS). RESULTS:After PSM, 128 patients were included (64 per group). Among patients with available imaging follow-up (54 in the conventional group and 55 in the variant group), adequate occlusion rates were comparable between the variant and conventional ACA groups (81.5% vs. 85.5%; p = 0.600). No significant differences were observed in ischemic or hemorrhagic complications, vasospasm, or long-term clinical outcomes. Sensitivity analyses confirmed the robustness of the findings. CONCLUSIONS:ACA anatomical variants do not adversely affect the safety or efficacy of endovascular treatment for DACA. With appropriate anatomical assessment and treatment selection, endovascular therapy remains effective even in the presence of complex ACA configurations.

BACKGROUND:Final infarct volume (FIV) on 24-hour magnetic resonance imaging is a well-established imaging biomarker linked to functional recovery after ischemic stroke, yet its prognostic value in intracranial atherosclerosis-related large vessel occlusion remains poorly explored. The impact of adjunct intracranial stenting on both infarct size and progression also remains unclear in this population. This study aimed to examine the association between FIV and clinical outcome, evaluate the effect of adjunct stenting on FIV and infarct progression, and assess the relationship between infarct progression and functional independence. METHODS:We conducted a post hoc secondary analysis of the RESCUE-ICAS registry (Registry of Emergent Large Vessel Occlusion due to Intracranial Stenosis); only patients with anterior circulation large vessel occlusion with magnetic resonance imaging after thrombectomy were included. FIV was measured on diffusion-weighted magnetic resonance imaging performed 24 to 36 hours postthrombectomy. Infarct progression was defined as the difference between baseline computed tomography perfusion infarct volume (cerebral blood flow <30%) on presentation and 24- to 36-hour FIV. The primary outcome was 90-day functional independence (modified Rankin Scale score 0-2). Additional analyses evaluated the association between adjunct intracranial stenting and FIV, and the association between infarct progression and 90-day functional outcome. Associations were analyzed using multivariable logistic regression and inverse probability of treatment weighting. RESULTS:=0.008). CONCLUSIONS:Among intracranial atherosclerosis-related large vessel occlusion patients, 24- to 36-hour FIV is a strong predictor of functional outcome. Adjunct stenting is associated with smaller FIV. Lower infarct progression was also associated with favorable outcome. These findings highlight FIV as a reliable imaging biomarker and potential surrogate end point in future trials.

BACKGROUND:Intracranial atherosclerotic disease (ICAD) is a major cause of large vessel occlusion (LVO) stroke and presents unique challenges for endovascular treatment (EVT). PURPOSE/OBJECTIVE:To compare angiographic and clinical outcomes after EVT in patients with ICAD-related versus non-ICAD LVO. DATA SOURCES/METHODS:PubMed, Embase, Web of Science, and Cochrane Central Register of Controlled Trials were searched from inception through July 2025. STUDY SELECTION/METHODS:Studies enrolling adults with LVO undergoing EVT that directly compared ICAD and non-ICAD etiologies were included. DATA ANALYSIS/METHODS:Random-effects models were used to pool odds ratios (OR). Risk of bias was assessed with ROBINS-I, and certainty of evidence (CoE) was evaluated using GRADE. DATA SYNTHESIS/RESULTS:Eighteen studies (3 prospective and 15 retrospective) comprising 11,326 patients (1,571 ICAD; 9,755 non-ICAD) were included. Mean age across cohorts was 72.8 years, and hypertension was the most common comorbidity. ICAD was associated with lower odds of successful reperfusion (OR, 0.46; 95%CI, 0.31-0.70; p<0.001; very-low CoE) and lower risk of sICH (OR, 0.72; 95%CI, 0.54-0.96; p=0.025; low CoE). No significant differences were observed for functional independence (OR, 0.90; 95%CI, 0.67-1.22; p=0.51; very-low CoE), favorable functional outcome (OR, 0.80; 95%CI, 0.43-1.51; p=0.45; very-low CoE), or mortality (OR, 1.16; 95%CI, 0.77-1.75; p=0.48; very-low CoE). LIMITATIONS/CONCLUSIONS:Included studies were observational, most were retrospective, and pooled estimates were derived from unadjusted comparisons. CONCLUSIONS:In pooled unadjusted comparisons, ICAD was associated with lower reperfusion success but similar functional and mortality outcomes compared to non-ICAD LVO, alongside a lower risk of symptomatic hemorrhage. These findings highlight the distinct pathophysiology of ICAD-LVO and the need for tailored EVT strategies and randomized trials for this population.

BACKGROUND:Middle meningeal artery embolization (MMAE) has emerged as a treatment for chronic subdural hematoma (cSDH), but comprehensive real-world safety data remain limited. METHODS: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. RESULTS:Mean age was 72.8 ± 12.4 years; 68.1% were male. The 30-day complication rate was 5.1% (91/1781; 95% CI, 4.1-6.2). In-hospital mortality was 2.9% (47/1625). Technical success was achieved in 97.5% (1505/1543). Among documented complications, thromboembolic events were most common (37.2%; 32/86), followed by hemorrhagic complications (23.8%; 20/84) and access-site hematoma (10.4%; 8/77). Among patients with classifiable symptom status, 80.6% of complications were symptomatic, yielding an overall symptomatic complication rate of 3.0%. Neurological deterioration occurred in 27.1% (248/915). Among 1552 patients with documented surgical approach, complication rates were similar between surgery plus embolization (4.9%; 34/690) and embolization alone (5.2%; 45/860; OR, 0.94; 95% CI, 0.59-1.48; p = 0.79). After IPTW adjustment, technical success was associated with an 86% reduction in complication odds (OR, 0.14; 95% CI, 0.05-0.40; p < 0.001). CONCLUSIONS:In this large multicenter cohort, MMAE was associated with a 5.1% complication rate. Technical success was the strongest protective factor. Embolization with or without surgery showed equivalent safety profiles.

PURPOSE/OBJECTIVE: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. METHODS: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). RESULTS:Among 1,220 patients, 342 (28.0%) presented with ruptured aneurysms. Propensity-score-matched analyses revealed no significant difference in thromboembolic complications (11.8% vs. 5.9%, p = 0.056), similar periprocedural adequate occlusion (53.3% vs. 53.8%, p > 0.9), and similar retreatment rates (11.8% (95% CI 7.8-17.6%) vs. 7.1% (95% CI 4.1-12.0%), p = 0.14); however, adequate occlusion at follow-up was lower (82.2% vs. 93.3%, p = 0.002) and functional outcomes were worse (mRS ≥ 2 in 34.1% vs. 21.9%, p = 0.012) among patients with ruptured aneurysms. CONCLUSION/CONCLUSIONS:Ruptured aneurysms demonstrated expected inferior follow-up functional and angiographic outcomes when compared with unruptured aneurysms, but no difference in retreatment rate and procedural safety. These findings support WEB as a safe and effective treatment option for appropriately selected ruptured intracranial aneurysms in routine clinical practice.

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.