Faculty Bibliography

This chapter reviews the vascular anatomy of the brainstem and posterior circulation with emphasis on clinical neurology and angiographic interpretation. Using a caudal-to-cranial approach, we describe the vertebral artery at the craniocervical junction and its key branches, including meningeal, medullary, spinal, and posterior inferior cerebellar arteries (PICA), highlighting common variants and clinically important anastamoses. We then outline basilar artery segments, pontine perforator patterns, and vertebrobasilar perforator groups, linking lesion location to characteristic neurologic syndromes. The cerebellar arteries (PICA, AICA, and superior cerebellar artery) are discussed with attention to variant origins, shared trunks, and collateral pathways that influence infarct topography. Finally, we summarize basilar tip and posterior cerebral artery (PCA) anatomy, including fetal PCA configurations, and thalamoperforator variants, such as the artery of Percheron.

BACKGROUND:Venous anatomical variants are common and generally considered normal. However, growing recognition of cerebral venous disorders (CVD) in neurological disease has prompted renewed interest in venous architecture, especially with increasing use of the internal jugular vein (IJV) as a target for outflow augmentation. Establishing baseline data on venous stenosis prevalence in an unselected population is critical for future research. This study aimed to assess the prevalence of IJV stenoses in patients undergoing neck CT angiography for unrelated indications. METHODS:We conducted a multicenter, retrospective study analyzing the venous anatomy of patients who underwent CT angiography for unrelated conditions, primarily large vessel occlusion. Stenosis was graded based on the percentage of lumen narrowing with a NASCET-style methodology, and the relationship between IJV stenosis severity and suboccipital collateral drainage was evaluated. Consecutive CT angiograms of patient were queried to map anatomical features. RESULTS:68% of the 679 total patients exhibited some degree of IJV stenosis. Severe unilateral stenosis (≥51%) was present in approximately 21% of patients, while complete or near-complete occlusion was uncommon at 8%. Bilateral high-grade stenosis was noted in 18% of patients for >50% stenosis and in only 2% of patients for >75% stenosis. A greater degree of stenosis correlated with increased suboccipital collateral vein diameter (p = 0.0025). CONCLUSION/CONCLUSIONS:IJV stenosis is common on CT angiography performed for non-venous indications with a correlation between the degree of stenosis and suboccipital collateral vein diameter. The clinical significance of these findings and its possible contribution to CVD requires further prospective investigation.

BACKGROUND:The Society of Vascular and Interventional Neurology (SVIN) Guidelines and Practice Standards Committee issues Brief Practice Updates to provide concise, evidence-based recommendations and suggestions on focused topics relevant to vascular and interventional neurology. Currently, there is limited published guidance on the technical performance and interpretative parameters of cerebral digital subtraction angiography for the determination of cerebral circulatory arrest in patients being evaluated for brain death/death by neurological criteria. In this Brief Practice Update, we present consensus-based suggestions for standardizing the performance, interpretation, and application of digital subtraction angiography in this context. METHODS:This Brief Practice Update was developed using the SVIN Standards and Parameters for Guideline Development in the classification of evidence and Class of Recommendation when evidence is available and Expert Opinion recommendation when evidence is lacking. The Guidelines and Practice Standards committee convened a multidisciplinary writing group to establish key clinical questions and develop a survey assessing Expert Opinion on the role of digital subtraction angiography in cerebral circulatory arrest determination. Survey items addressed technical considerations, interpretation criteria, and clinical integration. Iterative refinement was achieved through group consensus, and the final survey was distributed to a panel of experts in neurointervention and neurocritical care. The SVIN Guidelines and Practice Standards Quality Committee reviewed the findings for adherence to SVIN's internal evidence evaluation guidelines before submission to the SVIN board for societal endorsement. RESULTS:Evidence was evaluated by the writing group when available, and Expert Opinion was assessed using survey results. Suggested recommendations follow the established SVIN guideline framework for Class of Recommendation and Level of Evidence, with an Expert Opinion endorsement category for areas lacking high-quality evidence at the time of publication. CONCLUSIONS:This update standardizes how to perform, interpret, and report digital subtraction angiography when used to assess cerebral circulatory arrest in brain death/death by neurological criteria evaluations, aiming to improve reproducibility across centers. It provides a structured framework to improve consistency and reliability among practitioners performing and interpreting cerebral angiography in this setting.

BACKGROUND:The RESCUE-ICAS study (Registry of Emergent Large-Vessel Occlusion due to Intracranial Stenosis) demonstrated that patients undergoing acute stenting of intracranial atherosclerosis with large-vessel occlusion after mechanical thrombectomy had better outcomes than those undergoing mechanical thrombectomy alone. We present 2 secondary analyses of RESCUE-ICAS to evaluate intracranial stenting among patients who achieved successful reperfusion. METHODS:From a prospective observational cohort of 25 stroke centers (2022-2023), patients with acute intracranial occlusion, National Institutes of Health Stroke Scale score ≥6, and 50% to 99% residual stenosis or occlusion after endovascular thrombectomy were included. In the first analysis, we compared patients with stenting versus those without stenting from among those patients with a final modified Thrombolysis in Cerebral Infarction score of 2B-3. In the second analysis, we compared patients who underwent stenting with those who did not from among the patients with a Thrombolysis in Cerebral Infarction (TICI) score of 2B-3 before stenting. The odds of a favorable 90-day mRS (0-2) and 24-hour MRI infarct volume <30 mL were assessed using multivariable logistic regression. We also examined the rates of symptomatic ICH and death at 90 days in these cohorts. RESULTS:=0.480). CONCLUSIONS:Among both the cohort with final successful reperfusion and the cohort with initial successful reperfusion after mechanical thrombectomy alone, intracranial stenting was associated with better long-term clinical and radiographic outcomes, without higher morbidity and mortality. REGISTRATION/BACKGROUND:URL: https://www.clinicaltrials.gov; Unique identifier: NCT05403593.

PURPOSE/OBJECTIVE:Traditionally treated with microsurgical clipping, the treatment preference for intracranial aneurysms has shifted towards endovascular coiling. However, the choice between endovascular coiling and microsurgical clipping as the primary treatment strategy for ruptured middle cerebral artery (MCA) aneurysms remains disputed. We conducted a systematic review and meta-analysis to compare the radiological and clinical outcomes of ruptured MCA aneurysms treated with primary coiling and microsurgical clipping. METHODS:An extensive literature search was performed across PubMed, Embase, and Cochrane databases through August 2025. The primary outcomes of our study include the mRS scores at discharge and at long-term follow-up. Secondary outcomes include aneurysm occlusion post-procedurally or at discharge, and at long-term follow-up. Pooled risk ratios (RRs) with 95% confidence intervals (CIs) were calculated using a random-effects model. RESULTS:A total of 5 studies, involving 984 patients (coiling = 449, clipping = 535) were included. There are no significant differences in good functional outcome (mRS 0-2) among ruptured MCA aneurysms treated with either endovascular coiling or microsurgical clipping at discharge (RR: 1.04; CI: 0.93-1.18; p = 0.473) and long-term follow-up (RR: 1.07; CI: 0.95-1.20; p = 0.245), even though endovascular coiling is associated with lower rates of complete aneurysm occlusion at discharge (RR: 0.66; CI: 0.54-0.82; p < 0.001) and long-term follow-up (RR: 0.76; CI: 0.66-0.89; p < 0.001). CONCLUSION/CONCLUSIONS:Our meta-analysis suggests that while microsurgical clipping and primary coiling of ruptured MCA aneurysms had similar functional outcomes, clipping is associated with higher rates of complete aneurysm occlusion. Future studies with larger cohorts with prospective data, as well as studies that include more contemporary endovascular technologies and techniques, are warranted.

BACKGROUND/UNASSIGNED:Pituitary hyperemia and gland enlargement can be cardinal features of intracranial hypotension secondary to cavernous sinus and epidural venous plexus distention. This phenomenon can therefore complicate radiographic interpretation of sellar lesions when both diagnoses co-exist. We report a unique case of a rapidly enlarging pituitary macroadenoma in the setting of a thoracic cerebrospinal fluid (CSF)-venous fistula causing symptomatic intracranial hypotension. CASE DESCRIPTION/UNASSIGNED:A 53-year-old female with no prior neurosurgical history presented with recurrent orthostatic headache. Magnetic resolution imaging revealed a pituitary lesion along with pathopneumonic signs of intracranial hypotension. The tumor grew rapidly on surveillance imaging, prompting consideration of surgery. Further work-up, however, revealed a thoracic CSF-venous fistula. Endovascular embolization of the fistula led to near-complete resolution of her symptoms and durable radiographic tumor regression. CONCLUSION/UNASSIGNED:Pituitary macroadenomas are susceptible to local hemodynamic changes occurring as a sequelae of occult CSF leak. Identification and treatment of the underlying etiology were sufficient to induce tumor regression.

PURPOSE/OBJECTIVE:Rescue stenting (RS) can achieve durable recanalization in cases of acute large vessel occlusion due to underlying intracranial artery stenosis (ICAS), but its clinical effects may be influenced by procedural factors. This study aimed to evaluate whether the severity of stenosis affects the outcomes after RS. METHODS:In this multicenter retrospective study, patients with acute middle cerebral artery occlusion and underlying ICAS were divided into two groups based on the treatment they received: mechanical thrombectomy (MT) + RS (n = 172) or MT-only (n = 131). Inverse probability of treatment weighting was used to balance baseline characteristics. We systematically evaluated stenosis thresholds from 40% to 90% to identify the optimal cutoff that best differentiated treatment effects on the 90-day modified Rankin Scale (mRS) score and safety outcomes, including symptomatic intracranial hemorrhage (sICH). RESULTS:A stenosis severity of 75% was identified as the optimal cutoff for effect modification. While RS improved recanalization rates overall, its effect on the 90-day mRS score was beneficial only in patients with > 75% stenosis compared to MT-only (Average Treatment Effect (ATE) -0.98, 95% CI -1.73 to -0.22; p = 0.01). In contrast, it showed a detrimental effect in those with < 75% stenosis (ATE 1.08, 95% CI 0.32 to 1.83; p = 0.005). Furthermore, RS increased the rate of sICH regardless of ICAS severity. CONCLUSIONS:The clinical benefit of RS is contingent on the underlying stenosis severity, providing favorable outcomes in patients with high-grade stenoses only. ICAS severity should also be considered for treatment decisions, though these findings require validation in prospective controlled studies.

Data on the use of Woven EndoBridge (WEB) devices in the treatment of narrow-neck intracranial aneurysms (NNA) are limited. We compared the efficacy and safety of single-layer (SL) and single-layer spherical (SLS) WEB devices in treating NNA. We conducted a multicenter retrospective analysis of adult patients with NNA (neck ≤ 4 mm and width-to-neck ratio ≥ 2) treated with SL or SLS WEB devices between January 2011 and December 2022. Patients with fusiform or blister aneurysms, adjunctive treatments, or devices other than SL or SLS were excluded. Propensity score matching was used to adjust for confounding variables. Outcomes included procedural complications, angiographic occlusion rates using the Raymond Roy classification, major device compaction, need for retreatment, and functional outcomes assessed by the modified Rankin Scale (mRS). After matching, resulting in 101 patients in each group, baseline characteristics were well-balanced. Thromboembolic complications occurred in 2.0% of the SLS group and 5.9% of the SL group (P = 0.28). Hemorrhagic complications occurred in 1.0% of the SLS group and 6.4% of the SL group (P = 0.062). Adequate occlusion rates (Raymond Roy grades I and II) were similar between groups (96% in SLS vs. 91% in SL; P = 0.20). Major device compaction was significantly less frequent in the SLS group compared to the SL group (0% vs. 7.6%; P = 0.024). The need for retreatment trended to be lower in the SLS group (1.1% vs. 6.6% in SL; P = 0.12). Functional outcomes (mRS 0–1) at last follow-up were comparable (82% in SLS vs. 86% in SL; P = 0.41). In the treatment of narrow-neck intracranial aneurysms, the SLS WEB device was associated with significantly lower rates of major device compaction compared to the SL device. Reduced compaction may lead to a lower need for retreatment. Overall imaging outcomes and safety profiles were similar between the two devices.

BACKGROUND:Flow diverters (FDs) are increasingly used for cerebral aneurysms, including distal anterior cerebral artery (DACA) aneurysms, but comparative data between devices in this challenging location are limited. OBJECTIVE:To compare the safety and efficacy of Pipeline, Silk Vista Baby (SVB), and FRED Jr. FDs for unruptured DACA aneurysms and identify predictors of complete occlusion. METHODS:We retrospectively analyzed 166 patients treated with FDs at 39 centers in 14 countries (2018–2022) from the CRETA registry. Outcomes included aneurysm occlusion (O’Kelly–Marotta [OKM] scale), complications, retreatment, modified Rankin Scale (mRS) scores, and independent predictors of complete occlusion using multivariable Cox regression. RESULTS:Aneurysms were predominantly saccular and located on the pericallosal artery. Complete occlusion (OKM D) was achieved in 73%, and neck remnants (OKM C) in 12%, with no differences across devices. Ischemic complications occurred in 11% (mostly asymptomatic), hemorrhagic complications in 5%, and in-stent stenosis in 17%. Retreatment was performed in 1.3%. At last follow-up, 98% had mRS ≤ 2. Independent predictors of complete occlusion were female sex (HR 1.85), asymptomatic presentation (HR 1.79), smaller aneurysm neck (HR 0.83/mm), radial access (HR 2.20), and aspirin plus ticagrelor therapy (HR 1.84); device type was not predictive. CONCLUSION:Pipeline, SVB, and FRED Jr. FDs show similar safety and efficacy for unruptured DACA aneurysms. Complete occlusion is influenced by clinical and procedural factors, supporting individualized device selection.