Faculty Bibliography

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.

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.

Definitive endoluminal reconstruction, widely known as flow diversion, revolutionized treatment of brain aneurysms. A range of targets, by location, size, etiology, and acuity, can be cured with an excellent risk/benefit profile. Requirement for effective antiplatelet state is balanced with superior treatment durability. Implant and delivery system technology continue to evolve. Some aneurysm types/locations remain undertreated. Maximizing efficacy while minimizing risks requires deep understanding of flow diversion principles, pathologic anatomy, endoluminal implants, delivery systems, and clinical management.

Although the concept of treating cerebral aneurysms by filling the sac from the inside (endosaccular) started many years ago first with detachable balloons and then coils, the use of a single metallic resheathable device acting as a flow disruptor is a much more recent innovation. The most studied device among these is certainly the WEB, which became part of standard clinical practice for treatment of wide-neck bifurcation aneurysms. This study reviews the most important features of the WEB device with a short summary of the most important literature. A small section at the end reviews also other endosaccular devices.

Imaging follow-up is an established component of intracranial aneurysm management that allows ongoing assessment of rupture risk and timely intervention to maintain protection from bleeding. Yet the frequency, duration, and imaging modality for follow-up vary widely. This review outlines contemporary imaging techniques and practice for follow-up of treated and untreated aneurysms, highlighting existing knowledge gaps and technical limitations that limit standardization. Updated evidence on the expected evolution and long-term outcome of common treatment strategies is presented to guide accurate reporting of radiological outcome after treatment and considerations regarding follow-up regimen.

The anatomy of vertebrobasilar perforators has been widely studied in human cadavers, with most reports found in the neurosurgical literature. These arterial perforators are extremely hard to visualize consistently with traditional two-dimensional digital subtraction angiography, but are reliably visible with cross sectional cone beam CT techniques. A clear understanding of this specific neurovascular anatomy and pathology is essential for informed treatment decisions. This review analyzes the anatomy of vertebrobasilar perforators with a focus on practical implications for aneurysm treatment, particularly flow diversion.

BACKGROUND AND PURPOSE/OBJECTIVE:In patients with acute large vessel occlusion (LVO) of the MCA and underlying intracranial artery stenosis (ICAS), rescue stenting (RS) has been associated with better angiographic outcomes and higher rates of functional independence compared to mechanical thrombectomy (MT) alone. However, uncertainty exists regarding safety of RS in patients at higher risk for intracranial bleeding.The primary aim of this retrospective multicenter study was to compare safety outcomes between patients with acute ICAS-LVO of the MCA who underwent MT and RS with or without prior intravenous thrombolysis (IVT). Efficacy outcomes were assessed as a secondary aim. METHODS:We screened the prospective databases of 26 stroke centers across Europe, the United States, and China for consecutive patients with acute MCA ICAS-LVO who received RS. Patients were divided into two groups based on prior administration of IVT: IVT/RS and no-IVT/RS. Propensity score matching (PSM), based on a set of covariates that also included peri-procedural antiplatelet therapies, was used to estimate the effect of IVT treatment. Primary safety outcomes were the occurrence of symptomatic intracranial hemorrhage (sICH) and 90-day mortality. RESULTS:After PSM, 52 pairs of patients were available for analysis. No significant differences were observed between the two groups regarding rates of sICH (11.5% in IVT/RS group vs. 9.6% in no-IVT/RS group, OR 1.2, 95% CI 0.4-4.3, p = 0.75) and 90-day mortality (14.3% in the IVT/RS group vs. 11.7% in the no-IVT/RS group, OR 1.3, 95% CI 0.4-4.2, p = 0.71). There were also no significant differences in the occurrence of parenchymal hemorrhage types 1 and 2, successful recanalization rates and 90-day functional outcome. CONCLUSIONS:The safety of RS in ICAS-LVO is not significantly affected by prior IVT administration. Furthermore, IVT does not result in improved recanalization and clinical outcome. These findings should be interpreted with caution and require validation through future randomized controlled studies. ABBREVIATIONS/BACKGROUND:MT＝ mechanical thrombectomy; LVO＝ large vessel occlusion; ICAS = intracranial artery stenosis; RS = rescue stenting; IVT = intravenous thrombolysis; sICH = symptomatic intracranial Hemorrhage; PH = parenchymal hematoma; SD = standard deviation; IQR = interquartile range; PSM = propensity score matching; SMD = standardized mean difference; OTG = onset-to-groin; GPI = glycoprotein IIb/IIIa inhibitors.

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.

OBJECTIVE:To validate the carotid web (CW) risk stratification assessment described in previous works within a larger cohort of patients with symptomatic and incidentally found asymptomatic CWs. METHODS:A retrospective analysis of our institution's electronic medical records identified all patients with a diagnosis of CW from 2017 to 2024. We included symptomatic patients and those with asymptomatic CWs, that is, incidentally found webs without history of stroke or transient ischemic attack. Patient charts were reviewed for demographics, imaging, comorbidities, and a diagnosis of stroke after diagnosis of asymptomatic CW. All angles were measured as described in previous work on a sagittal reconstruction of neck CT angiography in which the common carotid artery (CCA), external carotid artery, and internal carotid artery (ICA) were well visualized, together with the CW itself. Principal component analysis and logistic regression were performed to evaluate the association between high-risk angles and stroke risk.  RESULTS: Twenty-six symptomatic and 26 asymptomatic patients were identified. Of note, the number of patients with hypertension, hyperlipidemia, and smoking history was 17 (65.0%), 16 (62.0%), and 8 (31.0%) for symptomatic patients and 18 (69.0%), 17 (65.0%), and 15 (58.0%) for asymptomatic patients. All angular measurements showed statistically significant associations with stroke status. The CCA-web-pouch angle showed the strongest association (p=2.07×10⁻⁴), followed by the CCA-pouch-tip angle (p=3.23×10⁻⁴), ICA-web-pouch angle (p=0.004), and ICA-pouch-tip angle (p=0.005). Each additional high-risk angle increased the odds of stroke by 9.47-fold (p<0.0001). The associated probability of stroke increased from 6.3% with no high-risk angles to 39.1% with one high-risk angle and further to 85.9% with two high-risk angles. The model demonstrated high sensitivity, correctly identifying 84.6% of positive cases, and high specificity, correctly identifying 88.5% of negative cases. The F1 score was 0.863, indicating good overall model performance.  CONCLUSION: Given this successful stratification of CWs into high- and low-risk groups, the utilization of geometric CW parameters may play a role in improving patient selection for intervention in the setting of incidentally diagnosed CW. .