Faculty Bibliography

BackgroundDuring mechanical thrombectomy for large-vessel occlusions, a ledge effect makes navigating the aspiration catheters (ACs) to the occlusion difficult. New large-bore macrowires minimize this while ensuring flexibility and navigational control. We evaluated the technical feasibility of delivering large-bore ACs to posterior circulation occlusions.MethodsThis retrospective multicenter study evaluated patients treated for posterior circulation strokes with adjunct-free macrowire-only direct aspiration first-pass technique (MO-ADAPT) using 0.024- and 0.035-in macrowires between October 2022 and December 2024. Primary outcomes included successful catheter delivery, successful MO-ADAPT (i.e. adjunct-free catheter delivery and successful clot aspiration), and first-pass reperfusion (i.e. modified thrombolysis in cerebral infarction (mTICI) score ≥ 2b after one MO-ADAPT pass).ResultsAmong 42 included patients (mean age 68.3 ± 15.4 years), adjunct-free delivery of ACs to the occlusion using macrowires only was successful in 95.2%. An MO-ADAPT primary approach achieved successful reperfusion in 81.0%, with first-pass reperfusion in 54.8%. Among patients with successful AC delivery, the aspiration success rate was 85.0%. Final mTICI scores of 3, 2c, and 2b after all procedures were seen in 78.6%, 14.3%, and 4.8%, respectively, regardless of thrombectomy method. No vascular complications were observed, and postprocedural intracranial hemorrhage and distal emboli occurred in 2.4% each. A favorable clinical outcome at 90 days was observed in 33.3% of cases. Multivariable analysis showed that underlying intracranial atherosclerotic disease was a negative predictor of both MO-ADAPT success and first-pass reperfusion; no factors predicted AC delivery success.ConclusionIn this retrospective series, MO-ADAPT appeared to be technically feasible for treating posterior circulation strokes, with promising procedural results and a low complication rate. Observed failures were mainly associated with underlying intracranial atherosclerotic disease requiring stent retriever-assisted mechanical thrombectomy. Given the limited sample size and study design, further studies, ideally with larger cohorts and comparative designs, are necessary to clarify the relative safety, efficacy, and cost effectiveness of MO-ADAPT.

PURPOSE/OBJECTIVE:Mechanical thrombectomy (MT) is standard care for acute large vessel occlusion (LVO), but it fails in 10-20% of cases, often due to underlying intracranial artery stenosis (ICAS). In such cases, rescue stenting (RS), with or without angioplasty, may improve recanalization, but its clinical benefit remains debated. The purpose of this study was to define predictors of clinical outcome in this patient population. METHODS:We conducted a retrospective multicenter study including 115 patients with ICAS-related occlusion of the middle cerebral artery (MCA) treated with MT and RS across 27 international stroke centers. Baseline, procedural, and post-procedural variables were analyzed. The outcome measure was the ordinal shift of the 90-day modified Rankin Scale (mRS) score. Stepwise multivariate regression and structural equation modeling (SEM) were used to identify outcome predictors and explore mediation pathways. RESULTS:Successful recanalization (modified Treatment in Cerebral Infarction (mTICI) score ≥ 2b) was achieved in 94.8% of patients, with 73.0% reaching mTICI 2c‑3. SEM showed that baseline Alberta Stroke Program Early CT Score (ASPECTS), stenting with angioplasty and achieving mTICI 2c‑3 were associated with improved functional outcome, mediated by higher post-procedural ASPECTS. Post-procedural ASPECTS influenced functional outcome both directly (estimate = -0.45, p < 0.001) and indirectly by reducing the occurrence of symptomatic intracranial hemorrhage (sICH) (estimate = -0.09, p = 0.004). This model explained 36.5% of the variance in 90-day mRS scores. CONCLUSION/CONCLUSIONS:In patients with acute ICAS-related MCA occlusion, stenting with angioplasty and achieving mTICI 2c-3 recanalization are associated with improved clinical outcome. These benefits are mediated by better post-procedural ASPECTS and reduced sICH. Prospective studies are warranted to confirm these findings.

Spinal dural arteriovenous fistulas (dAVFs) at the craniocervical junction are rare vascular lesions that can cause progressive myelopathy and paralysis. This video presents a 40-year-old male with a left C1 spinal dAVF, who experienced unsteadiness, dizziness, leg weakness, and intermittent facial numbness. Given the lesion's symptomatology, the patient underwent a C1 laminectomy and midline suboccipital craniectomy for definitive obliteration. The authors describe key surgical techniques for fistula exposure and obliteration, with intraoperative angiographic confirmation. Long-term follow-up confirmed complete persistent occlusion on angiography and resolution of his symptoms. This case highlights surgical strategies for managing dAVFs at the craniocervical level. The video can be found here: https://stream.cadmore.media/r10.3171/2025.7.FOCVID2573.

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 (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). CONCLUSION/CONCLUSIONS: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.

BACKGROUND:Recent studies have suggested that favorable venous outflow (VO) may be a promising imaging biomarker to predict clinical outcomes following reperfusion therapy in patients with acute ischemic stroke caused by large vessel occlusion (AIS-LVO). METHODS:A comprehensive literature search was conducted in PubMed, Scopus, WOS, and Cochrane to identify studies that evaluated VO profiles, assessed using the Cortical Vein Opacification Score (COVES). The risk ratio (RR) and 95% confidence interval (CI) for the outcomes, including functional independence, assessed by modified rankin scale at 90 days (mRS 0-2), hemorrhagic infarction, parenchymal hematoma, 90-day mortality, intracranial hemorrhage (ICH), and symptomatic ICH (sICH), were calculated and analyzed using the 'meta' package in R version 4.4.1. RESULTS:A total of six studies encompassing 2249 patients were included. Patients with favorable VO had a higher likelihood of achieving functional independence at 90 days (RR = 2.15; 95% CI: 1.35, 3.42; p = 0.01) and a lower incidence of 90-day mortality (RR = 0.39; 95% CI: 0.30, 0.51; p < 0.01), parenchymal hematoma (RR = 0.36; 95% CI: 0.27, 0.47; p < 0.01). Furthermore, sICH was less frequent in patients with favorable VO (RR = 0.39; 95% CI: 0.17, 0.89; p = 0.03). However, hemorrhagic infarction and any ICH did not differ significantly between the two groups (p-values: 0.06 and 0.32, respectively). CONCLUSION/CONCLUSIONS:VO is a promising imaging biomarker for predicting outcomes in patients with AIS-LVO following reperfusion therapy. Prospective clinical trials are warranted to investigate the predictive value of VO, assessed on multiphasic computed tomography angiography (CTA), as a prognostic marker in this patient population.

Medium vessel occlusions represent a substantial proportion of patients with acute ischemic stroke. Recently presented randomized controlled trials, ESCAPE-MeVO (Endovascular Treatment to Improve Outcomes for Medium Vessel Occlusions), DISTAL (Endovascular Therapy Plus Best Medical Treatment [BMT] Versus BMT Alone for Medium Distal Vessel Occlusion Stroke), and DISCOUNT (Evaluation of Mechanical Thrombectomy in Acute Ischemic Stroke Related to a Distal Arterial Occlusion), did not demonstrate a clinical benefit of endovascular thrombectomy in distal and medium vessel occlusions, potentially generating uncertainty about optimal treatment strategies for medium vessel occlusions. Specifically, these results may lead clinicians to hesitate in performing endovascular thrombectomy for M2 occlusions, despite prior evidence indicating benefit in this subgroup. In this review, we critically examine current literature, focusing on anatomic and functional definitions of M2 segments, and highlight the significant heterogeneity in their classification. We place a particular emphasis on proximal as well as dominant M2 branches and the existing evidence, including observational studies, meta-analyses, and prior randomized trials. Additionally, we discuss methodological limitations and patient-selection biases of recent neutral trials, which may warrant caution in the broad application of their findings. Lastly, we propose recommendations for future research, emphasizing the need for refined patient-selection criteria to better identify subgroups most likely to benefit from endovascular thrombectomy, improved classification systems for M2 occlusions, and the exploration of adjunctive and alternative therapies.

BACKGROUND:Osteogenesis imperfecta (OI) is a connective tissue disorder characterized by fragile bones and vascular fragility, increasing the risk of vessel dissection and potentially complicating endovascular intervention. The authors present the first case of cranial bypass in a patient with OI. OBSERVATIONS/METHODS:A 38-year-old male with OI type I presented with a symptomatic left internal carotid artery (ICA) occlusive dissection managed with endovascular revascularization and stenting. Follow-up surveillance imaging identified an incidental right ICA dissection, also treated with stenting. Four years later, the patient experienced new right hemispheric symptoms. He was found to have progressive right ICA dissection on best medical management. Following an unsuccessful restenting attempt, he underwent a successful double-barrel superficial temporal artery-to-middle cerebral artery (STA-MCA) bypass to restore cerebral perfusion with no perioperative complications. Six-month follow-up DSA confirmed a patent bypass with robust flow, and the patient remained asymptomatic 1 year postoperatively. LESSONS/CONCLUSIONS:STA-MCA bypass can serve as a viable and effective revascularization option in patients with OI, whose disease predisposes them to vascular dissection. In these high-risk patients, cranial bypass is a safe method for effective flow augmentation to hypoperfused brain regions when endovascular interventions fail. https://thejns.org/doi/10.3171/CASE25378.

BackgroundData on off-label use of flow diverter for ruptured distal anterior cerebral artery aneurysms (rDACAAs) are limited. The purpose of the present study is to evaluate the efficacy and safety of flow diversion for rDACAAs in a large multicenter cohort.MethodsA retrospective observational study on consecutive patients who were treated with flow diversion for rDACAAs at 8 centers in 4 countries was performed. Primary outcome was the occlusion rate of the target aneurysm at the last radiological follow-up. Secondary outcomes included good clinical outcome, retreatment, technical success, procedure-related complications, radiological outcome of the covered branches and mortality rate.ResultsA total of 21 patients with 21 rDACAAs were treated between January 2017 and December 2024. Thirteen patients were women (61.9%) and the median age was 54 years (IQR 46-66). The most common etiology was saccular (71.4%), followed by dissecting (23.8%) and mycotic (4.8%). In all patients a single stent was successful deployed. Median imaging follow-up was 9 (7-12) months. At last follow-up adequate occlusion was 95.2%. Symptomatic thromboembolic or hemorrhagic complications occurred in 9.5% of patients. Seventeen patients (81%) had good clinical outcome (mRS 0-2) with mortality rate of 9.5%. In-stent stenosis occurred in one case that was conservatively managed without major concerns.ConclusionsFlow diversion is feasible as a potential treatment strategy for acutely ruptured aneurysms arising from distal anterior cerebral artery. Flow diverter may represent a valid option whenever other treatments are considered challenging or high risk.

PURPOSE/OBJECTIVE:Treating small-caliber vessel aneurysms with flow diverters poses challenges due to narrow luminal diameters and tortuous vasculature, which complicate the navigation and deployment of conventional devices using standard microcatheters. The Silk Vista Baby (SVB, Balt, Montmorency, France) flow diverter was developed to treat intracranial aneurysms located in smaller vessels or more distal segments and is compatible with 0.017″ microcatheters. We present the largest multicenter analysis to date evaluating the outcomes of SVB use in unruptured distal anterior cerebral artery (DACA) aneurysms. METHODS:Retrospective data from 20 centers were reviewed for patients with unruptured DACA aneurysms treated with the SVB. Demographic information, clinical presentation, radiographic characteristics, complications, and outcomes were recorded. RESULTS:Seventy-nine patients (79 DACA aneurysms) were treated between January 2018 and December 2022; 59 were female (74.7%), and the median age was 61 years (IQR 53-67). Most aneurysms were saccular (89.9%), and 65.8% involved a branch. The median parent vessel diameter was 1.9 mm (IQR 1.7-2.1). A single stent was implanted in 97.5% of cases; 2.5% required two stents. The median imaging follow-up duration was 12 months (IQR 9.5-24). At the last follow-up, 76% of aneurysms showed complete or near-complete occlusion (O'Kelly-Marotta scale C or D, Raymond-Roy 1 or 2). Overall, thromboembolic or hemorrhagic complications occurred in 14% of patients, with two cases being symptomatic. The mortality rate was 0%, and the retreatment rate was 1.3%. CONCLUSION/CONCLUSIONS:In this multicenter series, the SVB flow diverter represented a valuable treatment option for distal anterior cerebral artery (DACA) aneurysms.