Tareq Kass-Hout

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.

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: Prehospital stroke screening for large vessel occlusions (LVOs) varies across institutions. This study compares manual stroke scale calculations against e-calculated scores using the Ultimate Stroke Scale (USS), a software automating multiple screening scales from a modified National Institutes of Health Stroke Scale (NIHSS) with a hand grip. The USS aims to streamline screening by computing multiple validated stroke scales simultaneously to enhance predictive value. Methods: We applied eight stroke screening scales (NIHSS; Balance, Eyes, Face, Arms, Speech, and Time [BE-FAST]; Vision, Aphasia, Neglect; Los Angeles Motor Scale [LAMS]; Face, Arm, Speech, Time, Eye Deviation and Denial/Neglect [FAST-ED]; Emergency Medical Services Rapid Arterial oCclusion Evaluation [EMS RACE]; 3-Item Stroke Scale [3-ISS]; and Prehospital Acute Stroke Severity [PASS]) to 199 stroke activations between January 2021 and December 2023. In this prospective, external validation study, data were utilized from a previously published head-to-head comparison of multiple LVO scales for both LVOs and medium vessel occlusions which collected scales manually. We recalculated these scales using the USS and evaluated agreement (Kendall's τ) and diagnostic accuracy (ROC curves). Results: The USS showed strong to moderate agreement with manual calculations across all scales displayed by Kendall's τ correlation coefficients ranging from 0.549 to 0.931 (all p < 0.001). The BE-FAST had the lowest agreement (τ = 0.549), while PASS had the highest (τ = 0.931), followed by LAMS (τ = 0.894) and FAST-ED (τ = 0.864). Diagnostic accuracy was comparable between manual methods (area under the curve [AUC]: 0.590–0.743) and the USS (AUC: 0.575–0.758). The BE-FAST had the lowest AUC for both, LAMS had the highest for manual, and FAST-ED had the highest from the USS. Conclusion: The USS demonstrates potential as a reliable tool for automated stroke screening with consistent performance compared to manual methods.

We present a case of an adult patient with a large symptomatic fusiform basilar artery aneurysm. This video demonstrates the ease of deploying the new Pipeline™ Vantage Flow Diverter compared to the Flex model in the same vessel. The Flex and Vantage have different deployment techniques—as using the Flex maneuvering technique on the Vantage may damage the braid. The Vantage stent does not require resheathing, dragging, or system loading. The video shows the operator's hands making multiple adjustments to deploy the Flex, while they deploy two Vantage stents and a LOBO ^® device occluder before fully deploying the Flex. The Vantage appears to offer a simpler, more streamlined deployment process of mostly unsheathing compared to the Flex flow diverter. Also, the Vantage design might offer a higher aneurysmal occlusion rate with a shorter course of anti-platelet regimen. ¹ Of note, the Pipeline™ Shield may be a more appropriate option in some cases.

Background Rapid prehospital identification of acute ischemic stroke secondary to large vessel occlusions (AIS-LVO) has been successful in triaging patients, but the use of stroke screening scales often varies. This study aims to compare different stroke screening scales for the detection of anterior and posterior circulation AIS-LVO and AIS secondary to medium vessel occlusions (AIS-MeVO). Methods We prospectively analyzed stroke alert activations at a comprehensive stroke center between August 1, 2022 and December 31, 2023. We applied eight stroke screening scales (BE-FAST, LAMS, PASS, FAST-ED, EMS RACE, 3-ISS, VAN, and NIHSS) to each stroke alert in the emergency department (ED) and inpatient wards. The final diagnosis was classified as AIS-LVO or AIS-MeVO, AIS without LVO or MeVO, intracranial hemorrhage, transient ischemic attack, or stroke mimic. Results A total of 198 patients were analyzed. The mean age was 63.9±15.3 years, 62.1% were female (n=123), and 84.3% were African American/black subjects (n=167). The LAMS scale had a strong performance (area under the curve (AUC) 0.750 (95% CI 0.668 to 0.831)), closely followed by the FAST-ED (AUC 0.736 (95% CI 0.649 to 0.822)) and the VAN (AUC 0.735 (95% CI 0.651 to 0.818)) scales. Cut-off points selected from coordinates of the receiver operating characteristic curves were 3, 3, and a positive VAN, respectively. Conclusion This is the first prospective cohort study to compare the performance of eight different screening scales among stroke alerts for detection of AIS-LVO and AIS-MeVO. We found LAMS to be the most discriminative tool, followed by FAST-ED and VAN. However, the findings were non-significant, reinforcing existing retrospective literature that these validated screening scales perform similarly and one is not superior.

Background: Acute ischemic stroke (AIS) due to intracranial atherosclerotic disease (ICAD) carries a high risk of recurrence despite aggressive medical management. The aim of our study is to present our initial experience with the Onyx Frontier™ balloon-mounted drug-eluting stent (Medtronic, Santa Rosa, CA) for AIS due to ICAD. Methods: We conducted a multicenter retrospective cohort study describing the technical feasibility, safety, and performance of using the Onyx Frontier™ balloon-mounted drug-eluting stent in patients with acute intracranial vessel occlusion due to ICAD across three comprehensive stroke centers in the United States. Results: We included 23 patients in our study (mean age 67.3 [10.7]; females: n = 13/23, 56.5%). Most patients were Black (n = 14/23, 60.9%). The most common site of vessel occlusion was the M1 branch of the middle cerebral artery (MCA) (n = 14/23, 60.9%), followed by the vertebrobasilar system (n = 5/23, 21.7%), and the internal carotid artery (n = 3/23, 13.0%). Treatment with the Onyx Frontier™ stent was associated with a final mTICI score ≥2b for 100% of patients, with no vessel perforations or distal embolization. None of the patients had any restenosis or re-treatment over a median follow-up of 3.5 months (interquartile range [IQR] 7.8). All cases required a single stent except for one, where two were deployed. Transfemoral access was used in most cases (n = 18/23, 78.3%), with one in-hospital death due to access site complication (n = 1/23, 4.3%). Conclusions: This is the largest multicenter cohort study demonstrating the feasibility and safety of using the Onyx Frontier™ balloon-mounted zotarolimus-eluting stent to treat symptomatic AIS due to ICAD.

Background: The optimal antiplatelet therapy regimen for certain neuroendovascular procedures remains unclear. This study investigates the safety and feasibility of intravenous dose-adjusted cangrelor in patients undergoing acute neuroendovascular interventions.Methods: We conducted a retrospective chart review of all consecutive patients on intravenous cangrelor for neuroendovascular procedures between September 1, 2020, and March 13, 2022. We also conducted an updated systematic review and meta-analysis using PubMed, Scopus, Web of Science, Embase and the Cochrane Library up to February 22, 2023.Results: In our cohort, a total of 76 patients were included [mean age (years): 57.2 ± 18.2, males: 39 (51.3), Black: 49 (64.5)]. Cangrelor was most used for embolization and intracranial stent placement (n = 24, 32%). Approximately 44% of our patients had a favorable outcome with a modified Rankin Scale (mRS) score of 0 to 2 at 90 days (n = 25/57); within 1 year, 8% of patients had recurrent or new strokes (n = 5/59), 6% had symptomatic intracranial hemorrhage [sICH] (4/64), 3% had major extracranial bleeding events (2/64), and 3% had a gastrointestinal bleed (2/64). In our meta-analysis, 11 studies with 298 patients were included. The pooled proportion of sICH and intraprocedural thromboembolic complication events were 0.07 [95% CI 0.04 to 1.13] and 0.08 [95% CI 0.05 to 0.15], respectively.Conclusion: Our study found that intravenous cangrelor appears to be safe and effective in neuroendovascular procedures, with low rates of bleeding and ischemic events. However, further research is needed to compare different dosing and titration protocols of cangrelor and other intravenous agents.

Background The transradial approach (TRA) for neurointerventional procedures is increasingly being used given its technical feasibility and safety. However, catheter trackability and device deliverability are reported barriers to TRA adoption. Methods This is the first report describing the technical feasibility and performance of using the Zoom RDL Radial Access System (Imperative Care, Inc., Campbell, CA) in 29 patients who underwent neurointerventional procedures from October 2022 to January 2023 in a single-center institution. Results Mean age of the study population was 61.9±17.2 years, 79.3% were male (23/29), and 62.1% were black (18/29). The most common procedures were stroke thrombectomy (31.0%, 9/29) and aneurysm embolization (27.6%, 8/29). All the stroke thrombectomy procedures were successfully performed; first-pass effect rate (mTICI≥2 c in one pass) was achieved in 66.7% (6/9) of cases. We used TRA in 86.2% of cases (25/29), including distal radial/snuffbox access in 31.0% (9/29) of cases. The radial diameter was >2 mm for all cases. An intermediate/aspiration catheter was used in 89.7% (26/29) of cases. Access success was achieved in 89.7% of cases (26/29); two cases required conversion from TRA to transfemoral approach (6.9%) and one case required conversion to a different guide catheter (3.4%). There were no access site complications or other Zoom RDL-related complications. One intracerebral hemorrhage, and one procedure-related thrombus were observed. Conclusions The use of Zoom RDL Radial Access System is technically feasible and effective for complex neurointerventional procedures with low complication rates.