Faculty Bibliography

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.

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.

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.

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.

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.

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 AND OBJECTIVES/OBJECTIVE:Dural arteriovenous fistula (dAVF) surgery is a microsurgical procedure that requires confirmation of obliteration using formal cerebral angiography, but the lack of intraoperative angiogram or need for postoperative angiogram in some settings necessitates a search for alternative, less invasive methods to verify surgical success. This study evaluates the use of indocyanine green videoangiography FLOW 800 hemodynamic intraoperatively during cranial and spinal dAVF obliteration to confirm obliteration and predict surgical success. METHODS:A retrospective analysis was conducted using indocyanine green videoangiography FLOW 800 to intraoperatively measure 4 hemodynamic parameters-Delay Time, Speed, Time to Peak, and Rise Time-across venous drainage regions of interest pre/post-dAVF obliteration. Univariate and multivariate statistical analyses to evaluate and visualize presurgical vs postsurgical state hemodynamic changes included nonparametric statistical tests, logistic regression, and Bayesian analysis. RESULTS:A total of 14 venous drainage regions of interest from 8 patients who had successful spinal or cranial dAVF obliteration confirmed with intraoperative digital subtraction angiography were extracted. Significant hemodynamic changes were observed after dAVF obliteration, with median Speed decreasing from 13.5 to 5.5 s-1 (P = .029) and Delay Time increasing from 2.07 to 7.86 s (P = .020). Bayesian logistic regression identified Delay Time as the strongest predictor of postsurgical state, with a 50% increase associated with 2.16 times higher odds of achieving obliteration (odds ratio = 4.59, 95% highest density interval: 1.07-19.95). Speed exhibited a trend toward a negative association with postsurgical state (odds ratio = 0.62, 95% highest density interval: 0.26-1.42). Receiver operating characteristic-area under the curve analysis using logistic regression demonstrated a score of 0.760, highlighting Delay Time and Speed as key features distinguishing preobliteration and postobliteration states. CONCLUSION/CONCLUSIONS:Our findings demonstrate that intraoperative FLOW 800 analysis reliably quantifies and visualizes immediate hemodynamic changes consistent with dAVF obliteration. Speed and Delay Time emerged as key indicators of surgical success, highlighting the potential of FLOW 800 as a noninvasive adjunct to traditional imaging techniques for confirming dAVF obliteration intraoperatively.

OBJECTIVE:The cause of perimesencephalic subarachnoid hemorrhage (pmSAH) is unclear but has historically been attributed to a venous source. The authors hypothesized that high-resolution cone-beam CT (CBCT) during angiography could better identify pmSAH etiology. METHODS:All patients with pmSAH treated at the authors' institution between January 2023 and December 2024 were retrospectively analyzed. Patients were excluded if CBCT was not performed as part of the digital subtraction angiography (DSA), if CBCT source data were not available for review, or if the images were deemed to be low quality. All images were reviewed by 2 neuroangiographers with extensive neurovascular imaging experience and discussed until consensus agreement. Data were recorded as counts and percentages. RESULTS:Among 152 patients who presented with spontaneous SAH in 2023-2024, 22 had a pmSAH defined according to the Rinkel criteria. These 22 patients had a catheter angiogram performed on 1 of 2 biplane machines. Thirteen of those patients had high-quality CBCT data available for review, 8 (61%) of whom were found to harbor a basilar perforator focal outpouching consistent with a site of rupture. All patients with pmSAH, including the 8 found to have a basilar perforator aneurysm, achieved an excellent neurological recovery with resolution of the basilar perforator finding on follow-up DSA with CBCT and without experiencing a re-rupture event or clinically significant vasospasm. CONCLUSIONS:In the setting of pmSAH, high-resolution CBCT acquired as part of catheter angiography frequently identifies a basilar perforator pseudoaneurysm. Conservative management was associated with excellent outcomes in this series. The authors propose that in the setting of pmSAH, a high suspicion of an arterial etiology should be considered until proven otherwise.

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.