Subacute and chronic subdural hematomas are common and frequently recur after surgical evacuation. The effect of adjunctive middle meningeal artery embolization on the risk of reoperation remains unclear. In a prospective, multicenter, interventional, adaptive-design trial, we randomly assigned patients with symptomatic subacute or chronic subdural hematoma with an indication for surgical evacuation to undergo middle meningeal artery embolization plus surgery (treatment group) or surgery alone (control group). The primary end point was hematoma recurrence or progression that led to repeat surgery within 90 days after the index treatment. The clinical secondary end point was deterioration of neurologic function at 90 days, which was assessed with the modified Rankin scale in a noninferiority analysis (margin for risk difference, 15 percentage points). A total of 197 patients were randomly assigned to the treatment group and 203 to the control group. Surgery occurred before randomization in 136 of 400 patients (34.0%). Hematoma recurrence or progression leading to repeat surgery occurred in 8 patients (4.1%) in the treatment group, as compared with 23 patients (11.3%) in the control group (relative risk, 0.36; 95% confidence interval [CI], 0.11 to 0.80; P = 0.008). Functional deterioration occurred in 11.9% of the patients in the treatment group and in 9.8% of those in the control group (risk difference, 2.1 percentage points; 95% CI, -4.8 to 8.9). Mortality at 90 days was 5.1% in the treatment group and 3.0% in the control group. By 30 days, serious adverse events related to the embolization procedure had occurred in 4 patients (2.0%) in the treatment group, including disabling stroke in 2 patients; no additional events had occurred by 180 days. Among patients with symptomatic subacute or chronic subdural hematoma with an indication for surgical evacuation, middle meningeal artery embolization plus surgery was associated with a lower risk of hematoma recurrence or progression leading to reoperation than surgery alone. Further study is needed to evaluate the safety of middle meningeal artery embolization in the management of subdural hematoma. (Funded by Medtronic; EMBOLISE ClinicalTrials.gov number, NCT04402632.).

BACKGROUND AND PURPOSE: Flow diversion with the Pipeline Embolization Device is increasingly used for endovascular treatment of intracranial aneurysms due to high reported obliteration rates and low associated morbidity. While obliteration of covered branches in the anterior circulation is generally asymptomatic, this has not been studied within the posterior circulation. The aim of this study was to evaluate the association between branch coverage and occlusion, as well as associated ischemic events in a cohort of patients with posterior circulation aneurysms treated with the Pipeline Embolization Device. MATERIALS AND METHODS: A retrospective review of prospectively maintained databases at 8 academic institutions from 2009 to 2016 was performed to identify patients with posterior circulation aneurysms treated with the Pipeline Embolization Device. Branch coverage following placement was evaluated, including the posterior inferior cerebellar artery, anterior inferior cerebellar artery, superior cerebellar artery, and posterior cerebral artery. If the Pipeline Embolization Device crossed the ostia of the contralateral vertebral artery, its long-term patency was assessed as well. RESULTS: A cohort of 129 consecutive patients underwent treatment of 131 posterior circulation aneurysms with the Pipeline Embolization Device. Adjunctive coiling was used in 40 (31.0%) procedures. One or more branches were covered in 103 (79.8%) procedures. At a median follow-up of 11 months, 11% were occluded, most frequently the vertebral artery (34.8%). Branch obliteration was most common among asymptomatic aneurysms (P < .001). Ischemic complications occurred in 29 (22.5%) procedures. On multivariable analysis, there was no significant difference in ischemic complications in cases in which a branch was covered (P = .24) or occluded (P = .16). CONCLUSIONS: There was a low occlusion incidence in end arteries following branch coverage at last follow-up. The incidence was higher in the posterior cerebral artery and vertebral artery where collateral supply is high. Branch occlusion was not associated with a significant increase in ischemic complications.

BACKGROUND AND PURPOSE: Incompletely occluded flow diverter treated aneurysms remain at risk of rupture and thromboembolic complications. Our aim was to identify the potential for incomplete occlusion of intracranial aneurysms treated by flow diverters. We investigated whether aneurysm ostium size in relation to parent artery size affects angiographic outcomes of flow diverter–treated sidewall aneurysms. MATERIALS AND METHODS: Flow diverter–treated sidewall aneurysms were divided into “occluded” and “residual” (incomplete occlusion) groups based on 6-month angiographic follow-up. We calculated the ostium ratio, a new parameter defined as the aneurysm ostium surface area versus the circumferential surface area of the parent artery. We also calculated the neck ratio, defined as clinical aneurysm neck diameter versus parent artery diameter from pretreatment 2D DSA, as a 2D surrogate. We compared the performance of these ratios with existing aneurysm morphometrics (size, neck diameter, volume, aspect ratio, size ratio, undulation index, nonsphericity index, ellipticity index, bottleneck factor, aneurysm angle, and parent vessel angle) and flow diverter–related parameters (metal coverage rate and pore density). Statistical tests and receiver operating characteristic analyses were performed to identify significantly different parameters between the 2 groups and test their predictive performances. RESULTS: We included 63 flow diverter–treated aneurysms, 46 occluded and 17 residual. The ostium ratio and neck ratio were significantly higher in the residual group than in the occluded group (P < .001 and P = .02, respectively), whereas all other parameters showed no statistical difference. As discriminating parameters for occlusion, ostium ratio and neck ratio achieved areas under the curve of 0.912 (95% CI, 0.838–0.985) and 0.707 (95% CI, 0.558–0.856), respectively. CONCLUSIONS: High ostium ratios and neck ratios could predict incomplete occlusion of flow diverter–treated sidewall aneurysms. Neck ratio can be easily calculated by interventionists to predict flow-diverter treatment outcomes.

Background Mechanical thrombectomy is the standard of care for large vessel occlusion (LVO) stroke, yet most device trials focus on individual technologies rather than complete systems. Objective To evaluate the safety and efficacy of the Zoom Reperfusion System compared with performance goals derived from a meta-analysis of trials using established thrombectomy technologies. Methods Prospective, multicenter, non-randomized, investigational device exemption trial conducted across 26 United States centers from October 2021 to March 2024. Adults with anterior circulation LVO stroke within 8 hours of onset were treated using the Zoom System, which includes aspiration catheters ranging from 0.035″ to 0.071″, and a novel 0.088″ intracranial guide/aspiration catheter. The primary efficacy endpoint was successful reperfusion (modified Thrombolysis in Cerebral Infarction (mTICI) 2b-3) within three passes using Zoom-only components, adjudicated by an independent core laboratory. The primary safety endpoint was symptomatic intracranial hemorrhage (sICH). Secondary outcomes included final reperfusion, first-pass success, time to reperfusion, 90-day modified Rankin Scale (mRS), and mortality. Results Among 260 patients (median age 68 years; median National Institutes of Health Stroke Scale (NIHSS) 15), successful reperfusion within three passes was achieved in 83% (216/259; 95% CI: 78% to 89%), exceeding the performance goal (p<0.001). Final reperfusion was 92%, with 5.5% requiring rescue devices. First-pass mTICI 2b-3 success was 57%. Median puncture-to-reperfusion time was 19 min. At 90 days, 55% achieved mRS 0–2. The sICH rate was 1.9%, and 90-day mortality was 12.7%. Conclusions The Zoom Reperfusion System demonstrated a safety and efficacy profile exceeding prespecified contemporary performance metrics with potential to significantly shorten reperfusion times and reduce the need for rescue therapy. Trial registration number ClinicalTrials.gov--Identifier:NCT04129125.

BACKGROUND AND PURPOSE: Tandem aneurysms are defined as multiple aneurysms located in close proximity on the same parent vessel. Endovascular treatment of these aneurysms has rarely been reported. Our aim was to evaluate the safety and efficacy of a single Pipeline Embolization Device for the treatment of tandem aneurysms of the internal carotid artery. MATERIALS AND METHODS: A retrospective analysis of consecutive aneurysms treated with the Pipeline Embolization Device between 2009 and 2016 at 3 institutions in the United States was performed. Cases included aneurysms of the ICA treated with a single Pipeline Embolization Device, and they were divided into tandem versus solitary. Angiographic and clinical outcomes were compared. RESULTS: The solitary group (median age, 58 years) underwent 184 Pipeline Embolization Device procedures for 184 aneurysms. The tandem group (median age, 50.5 years) underwent 34 procedures for 78 aneurysms. Aneurysms were primarily located along the paraophthalmic segment of the ICA in both the single and tandem groups (72.3% versus 78.2%, respectively, P = .53). The median maximal diameters in the solitary and tandem groups were 6.2 and 6.7 mm, respectively. Complete occlusion on the last angiographic follow-up was achieved in 75.1% of aneurysms in the single compared with 88.6%% in the tandem group (P = .06). Symptomatic thromboembolic complications were encountered in 2.7% and 8.8% of procedures in the single and tandem groups, respectively (P = .08). CONCLUSIONS: Tandem aneurysms of the ICA can be treated with a single Pipeline Embolization Device with high rates of complete occlusion. While there appeared to be a trend toward higher thromboembolic complication rates, this did not reach statistical significance.