Joseph Anthony Carnevale

BACKGROUND AND OBJECTIVES: The Woven Endobridge (WEB) and the Contour Neurovascular System (Contour) are both intrasaccular devices used to treat cerebral aneurysms. We compared outcomes of these 2 devices using data from 2 large registries. METHODS: Data were sourced from the WorldWideWEB Consortium, which included 1363 cases treated with WEB from 2017, and a registry of 277 Contour cases from 10 European centers starting the same year. Patient demographics, aneurysm characteristics, procedural specifics, and outcomes were analyzed. Propensity score matching was applied for comparison. RESULTS: Before matching, the Contour group had more men (37.9% vs 30.8%), more asymptomatic cases (83.4% vs 70.3%), and fewer acute subarachnoid hemorrhage cases (10.8% vs 26.2%). After matching, no significant differences were found in demographics or aneurysm characteristics between groups. The median age was 60 years, and median aneurysm dimensions were comparable. Logistic regression showed no significant differences between WEB and Contour in achieving complete occlusion (odds ratio [OR] = 1.01, 95% CI, 0.67-1.52, P = .971), adequate occlusion (OR = 0.85, 95% CI, 0.41-1.76, P = .665), or achieving modified Rankin Scale 0 to 2 at last follow-up (OR = 0.48, 95% CI, 0.21-1.02, P = .064). Retreatment (OR = 2.23, P = .086), thromboembolic complications (OR = 0.75, P = .452), and adjunctive treatment use (OR = 1.93, P = .141) were also similar. CONCLUSION: The WEB and Contour demonstrated comparable clinical and angiographic outcomes in this large multicenter study comprised majority small, asymptomatic cerebral aneurysms.

BACKGROUND AND OBJECTIVES: Middle meningeal artery embolization (MMAE) is effective for chronic subdural hematoma (SDH), but failure rates vary and risk prediction tools are lacking. This study developed and validated a machine learning (ML) model to predict MMAE treatment failure for SDH. METHODS: We conducted an international, multi-institutional retrospective cohort study of patients who underwent MMAE for SDH between 2019 and 2025. The cohort was split into training and test sets, stratified by treatment failure, with all hematomas from each patient assigned to a single cohort to prevent data leakage. Multiple ML algorithms were evaluated using 5-fold cross-validation, with gradient boosting selected as the final model. The primary outcome was treatment failure, defined as rescue surgical evacuation or persistent/recurrent SDH requiring retreatment. Model performance was assessed using area under the curve-receiver operating characteristic. Patients were stratified into low-risk (15%) groups using a priori clinically defined thresholds. RESULTS: Among 692 treated hematomas in the test cohort, 64 (9.2%) experienced treatment failure. The gradient boosting model achieved an area under the curve-receiver operating characteristic of 0.856 (95% CI, 0.803-0.902) before calibration and 0.832 (95% CI, 0.766-0.889) after isotonic calibration, with excellent calibration (Brier score, 0.053). The most important predictors were age-platelet interaction, platelet-hemoglobin ratio, platelet count, SDH thickness, and age. Observed treatment failure was 1.6% (95% CI, 0.4%-5.7%) in the low-risk group (n = 124; 17.9%), 6.0% (95% CI, 4.3%-8.4%) in the medium-risk group (n = 516; 74.6%), and 59.6% (95% CI, 46.1%-71.8%) in the high-risk group (n = 52; 7.5%) ( P < .001 for trend), a 37.2-fold difference between high- and low-risk groups. CONCLUSION: This ML model stratified MMAE patients into risk groups with a 37.2-fold difference in treatment failure. High-risk patients had 59.6% failure, whereas low-risk patients had 1.6% failure. Risk stratification may improve patient selection and monitoring.

Background Middle meningeal artery embolisation (MMAE) reduces treatment failure in chronic subdural haematoma (cSDH), but it remains unclear whether to add surgery and which patients benefit. We examined whether adding surgery improves functional recovery, accounting for admission status. Methods We conducted a multicentre cohort study of 2075 patients with cSDH treated with MMAE across 33 sites. The primary outcome was excellent functional recovery (modified Rankin Scale (mRS) 0–1) at the last recorded assessment, the timepoint with highest ascertainment (n=1854); a pre-specified 90-day analysis tested whether the timepoint determined the result. The effect modifier was admission functional status (mRS ≥2 vs 0–1), with doubly robust adjustment for measured baseline differences. Results Among 797 patients impaired at admission, excellent recovery occurred in 111/364 (30%) with surgery plus MMAE versus 101/433 (23%) with MMAE alone (adjusted difference 8.2 percentage points; 95% CI 0.8 to 15.5); among 1057 independent patients, it was 3.1 (−3.8 to 9.9). At 90 days, the impaired-group estimate was similar but less precise (7.5; −4.7 to 19.7; n=436), so the finding did not depend on the timepoint. The difference was largest with haematoma volume >80 mL (17.6; 6.6 to 28.6) and was absent for functional independence, freedom from recurrence or reoperation and survival. Surgical complications occurred in 9/195 (4.6%) impaired patients undergoing evacuation. Conclusions Adding surgery was associated with greater excellent functional recovery among admission-impaired but not already independent patients, consistently at 90 days and confined to the excellent-recovery threshold. Randomised validation stratified by admission function is warranted.

Purpose: Middle meningeal artery embolization (MMAE) is increasingly used for chronic subdural hematoma (CSDH), but the relationship between injected liquid-embolic volume and outcomes is unclear. We evaluated dose–outcome associations and searched for a minimum effective dose. Methods: This retrospective multicenter cohort included 313 patients treated with liquid embolic agents at 12 MESH Registry centers from 2016 to 2024. MMAE was performed alone in 172 patients (55.0%) and adjunctively with surgical evacuation in 141 (45.0%). Dose was assessed as total injected volume per patient and normalized to middle meningeal artery diameter, baseline hematoma thickness, and estimated hematoma volume. The primary outcome was a 180-day composite of retreatment, residual or recurrent hematoma > 10 mm, or death. Logistic regression with multiple imputation, restricted cubic splines, and sensitivity analyses evaluated associations and nonlinearity. Results: Median injected volume was 0.60 mL (interquartile range, 0.50–0.90). Center accounted for 44.5% of variation in log volume, whereas hematoma burden accounted for 0.3%. No dose metric was significantly associated with the primary outcome or 90-day recurrence/reoperation. For absolute volume, the odds ratio per interquartile-range increment was 0.80 (95% confidence interval, 0.56–1.16; p = 0.24). No reliable minimum effective dose was identified. Findings remained consistent across sensitivity analyses and treatment indications (interaction p = 0.30). Procedural complications occurred in 6.4% and were not dose-associated. Conclusion: Within the observed range, injected volume alone was not a consistent determinant of outcome and should not be a procedural target after a satisfactory angiographic endpoint. Future studies should evaluate embolic distribution, distal penetration, and vascular territory coverage.

Introduction: Nonacute subdural hematomas (nSDH) are common yet serious extra-axial hemorrhages that result in significant morbidity and mortality. Middle meningeal artery (MMA) embolization (MMAE) is a recent endovascular treatment that involves occlusion of the MMA, inducing hemostasis in and around the hematoma. While many aspects of MMAE have been explored, there is currently limited data on the optimal extent of embolization. Objective: To determine whether single or multiple pedicle embolization of the MMA is superior in inducing hemostasis in nSDH. Methods: We compared single versus multi pedicle embolization by a retrospective multicenter analysis of nSDH patients who underwent MMAE between 2019 and 2024 at participating centers in the MESH (MMA Embolization for Subdural Hematoma) Registry. 679 patients who received a liquid embolic agent with branch-level embolization data were included. Results: While multi-pedicle embolization hastened nSDH thinning at 1 month (5.7 vs. 3.3 mm reduction; difference 2.4 mm, 95% CI 1.0–3.8; P = .002), by 3 months thickness reduction had converged between groups (8.2 vs. 8.4 mm; P = .91). Among 679 patients (456 multi-pedicle, 223 single-pedicle), favorable functional outcome (mRS 0–2) was more frequent with multi-pedicle embolization (53.5% vs. 43.0%; adjusted OR 1.81, 95% CI 1.26–2.60; P = .001), whereas recurrence, rescue surgery, and treatment failure did not differ. Conclusion: Future, multi-center randomized prospective trials are warranted to address confounding variables that limit this observational study. Follow-up beyond 3 months was limited, so durability is unknown.

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 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. Objective To assess whether partially thrombosed aneurysms are at higher risk of recurrence or retreatment following WEB embolization compared with non-thrombosed aneurysms. Methods 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. Results 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 (PConclusion 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.