Faculty Bibliography

BACKGROUND AND OBJECTIVES/OBJECTIVE:Unruptured intracranial aneurysms (UIAs) are increasingly detected and require careful management to prevent rupture. No externally validated score currently predicts procedural risk to guide treatment decisions. We developed and validated 2 predictive scores for complications after endovascular treatment (EVT) or neurosurgical treatment (NT) of UIA using routinely collected clinical and aneurysmal features. METHODS:We conducted a multicenter retrospective study including patients with UIA treated with EVT or NT across 15 neurovascular centers (2014-2024). Predictive models were built using multivariable logistic regression, with variables derived from Delphi consensus. The primary outcome was a composite safety end point: new neurological deficits, modified Rankin Scale (mRS) worsening (≥1 point or mRS 2-5 within 30 days), or procedural death. Internal validation used bootstrapping, and external validation was performed temporally and institutionally. Model performance was assessed using area under the receiver operating characteristic curve (AUROC) and calibration. Final scores, named Morbidity and Mortality Associated Risk in the Treatment of UIAs (MARTA)-EVT and MARTA-NT, were compared with existing models identified through systematic review. RESULTS:Among 2647 patients (1907 EVT and 740 NT), procedural complications occurred in 6.3% (EVT) and 12.8% (NT). Independent predictors included age, baseline mRS, aneurysm location, size, morphology, and procedural factors. MARTA-EVT (AUROC = 0.68, 95% CI = 0.57-0.78) and MARTA-NT (AUROC = 0.65, 95% CI = 0.54-0.77) showed moderate discrimination and good calibration. MARTA-EVT outperformed existing models; MARTA-NT performed similarly to SAFETEA. Predictive models are available open-source: https://martascoreapp.shinyapps.io/martascoreapp/. CONCLUSION/CONCLUSIONS:MARTA-EVT and MARTA-NT are validated tools for predicting procedural risks in UIA treatment and may support patient counseling and clinical decision making.

BACKGROUND:Flow-diverter stents (FDS) have become the standard of care for a wide range of intracranial aneurysms, but their efficacy/safety in the context of recurrent/recanalized aneurysms following stent-assisted coiling (SAC) is not well established. We evaluate the outcomes of FDS retreatment in a large multicenter cohort. METHODS:We retrospectively analyzed data from 118 patients across 22 institutions who underwent FDS retreatment for recurrent/persistent aneurysms after SAC (2008-22). The primary outcome was angiographic occlusion status at last follow-up, categorized as complete (100%), near-complete (90-99%), or incomplete (<90%) occlusion. Secondary outcomes included procedural complications and clinical outcomes measured by the modified Rankin Scale (mRS). RESULTS:A total of 118 patients (median age 57, 74.6% female) with median follow-up of 15.3 months were identified. Complete occlusion was achieved in 62.5% and near-complete occlusion in 25%. FDS deployment within the pre-existing stent was successful in 98.3% of cases. Major complications occurred in 3.4% of cases, including postoperative aneurysmal rupture with resultant mortality (1.6%) and thromboembolic events with long-term disability (1.6%). Favorable clinical outcomes (mRS 0-2) were observed in 95.1% of patients. Wider aneurysm neck diameter was a significant predictor of incomplete occlusion (adjusted OR (aOR) 1.23 per mm, P=0.044), with male sex trending towards association with non-occlusion (aOR 3.2, P=0.07), while baseline hypertension was associated with complete occlusion (aOR 0.32, P=0.048). CONCLUSIONS:FDS treatment for recurrent/residual aneurysms after SAC represents a viable treatment option for these challenging cases with acceptable safety and reasonable occlusion rates, although lower than de novo FDS occlusion rates.

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.

BACKGROUND AND IMPORTANCE/BACKGROUND:Rhino-orbital cerebral mucormycosis (ROCM) is an aggressive fungal infection involving the paranasal sinuses, orbit, and intracranial cavity, with a propensity for vascular invasion. This can lead to complications such as internal carotid artery (ICA) thrombosis and occlusion, presenting major neurosurgical challenges. Although surgical debridement and antifungal therapy are the mainstays of treatment, cases with significant neurovascular involvement require specialized intervention. We report a case of ROCM with severe flow-limiting ICA stenosis treated by direct extracranial-intracranial bypass. CLINICAL PRESENTATION/METHODS:tA 65-year-old man with diabetes presented with progressive left-sided blindness and facial numbness. Imaging revealed a left orbital mass extending into the paranasal sinuses and intracranially. Empiric antifungal therapy was started. Pathology confirmed Rhizopus species. Despite extensive surgical debridement and antifungal therapy, the patient developed progressive severe cavernous ICA stenosis, leading to watershed territory strokes. To restore cerebral perfusion, protect from distal emboli, and prepare for potential aggressive debridement, a flow-replacing direct (superficial temporal artery-middle cerebral artery (M2)) bypass was performed, and the supraclinoid carotid was trapped. Intraoperative angiography confirmed robust flow through the bypass. The patient was discharged on antifungal therapy and aspirin. At 6-month follow-up, the patient was neurologically intact with an modified Rankin Scale score of 1. Computed tomography angiography and transcranioplasty Doppler ultrasonography confirmed good flow through the bypass. CONCLUSION/CONCLUSIONS:In addition to antifungal therapy and surgical debridement, superficial temporal artery-middle cerebral artery bypass can be a lifesaving intervention in the management of ROCM with severe cerebrovascular compromise. This case highlights the critical role of cranial bypass in preserving cerebral perfusion in patients with flow-limiting ROCM-associated ICA invasion.

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/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.

BACKGROUND AND OBJECTIVES/OBJECTIVE:Hand-sewn (HS) microsuturing is limited by tremor and fatigue. Robotic systems may improve performance, but quantitative comparisons remain limited. This study evaluates the precision of robot-assisted vs manual suturing during end-to-side microanastomosis. METHODS:Under simulation, microsurgical robot-assisted and HS sutures for end-to-side microanastomosis were performed by a single surgeon. One thousand four hundred and ninety-four total frames were assessed within 4 videos. Each robotic clip was paired with a corresponding HS clip. Tracker software extracted 2-dimensional positional data. Motion trajectories were smoothed using Savitzky-Golay filtering for an ideal suture trajectory. Deviation from an ideal path was quantified using Euclidean distance. Mean and SD of path deviation were calculated. Group comparisons were made as fold-change reductions and standardized effect sizes (Cohen d) to quantify the magnitude of observed differences. RESULTS:Robotic-assisted sutures demonstrated significantly lower mean path deviation and variability than HS sutures, particularly for the dominant (right) hand, with consistently large effect sizes for the right hand (all = 1.2, r = 0.5) and smaller for the left hand (d = 0.36-0.71, r = 0.18-0.33). CONCLUSION/CONCLUSIONS:Robotic microsuturing with microsurgical assistant significantly improves path fidelity, particularly in dominant-hand tasks. Manual sutures showed larger deviations between the ideal suture and raw data, supporting robotic integration into cerebrovascular neurosurgery and warranting study in live models.

The Woven EndoBridge (WEB) device treats wide-necked bifurcation aneurysms, but occlusion rates vary. This study aims to identify factors associated with immediate WEB device occlusion. Data from patients treated with WEB devices across 36 sites were analyzed. Machine learning algorithms and ordinal regression models were developed to predict immediate incomplete occlusion for ruptured and unruptured aneurysms. The study included 1565 patients, with 436 ruptured and 1129 unruptured aneurysms. Immediate complete occlusion was achieved in 38.3% of ruptured and 32.8% of unruptured aneurysms. For ruptured aneurysms, the CatBoost classifier achieved an AUROC of 0.69. Key predictors of incomplete occlusion included pretreatment mRS, aneurysm diameter, and MCA location. Ordinal regression revealed that smoking history (OR: 1.95, p < 0.001), neck diameter (Odds Ratio [OR]: 1.50, p < 0.001), and presence of a branch from the aneurysm (OR: 2.06, p = 0.016) were associated with incomplete, while bifurcation aneurysms (OR: 0.55, p = 0.017) were associated with complete immediate occlusion. For unruptured aneurysms, the CatBoost classifier achieved an AUROC of 0.68. Significant predictors of immediate incomplete occlusion included aneurysm neck width, MCA location, and presence of daughter sac. Ordinal regression revealed that smoking history (OR: 1.29, p = 0.032), neck diameter (OR: 1.24, p < 0.001), and presence of a daughter sac (OR: 1.53, p = 0.005) were associated with incomplete, while bifurcation aneurysms (OR: 0.71, p = 0.02) and posterior circulation location (OR: 0.68, p = 0.01) were associated with complete immediate occlusion. Careful evaluation of patient demographics and specific aneurysm characteristics may help improve the outcomes of intracranial aneurysms treated with WEB device.