Faculty Bibliography

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.

BACKGROUND AND OBJECTIVES/OBJECTIVE:The Silk Vista Baby (SVB) flow diverter (FD) stent (Balt SAS) is the first device designed for treating distally located brain aneurysms. It can be delivered through a 0.017-inch ID microcatheter, enabling access to small, distal vessels. The aim of this study was to evaluate the effectiveness, safety, technical success, occlusion rate, and clinical outcomes of the SVB device. METHODS:This retrospective, multicenter study included data from 18 centers from November 2023 to September 2024. Procedures were performed by experienced neurointerventionalists following institutional standards of care. Outcomes analyzed included effectiveness, safety, and aneurysm occlusion rates. Descriptive analyses and Pearson χ2 or Independent t-Test were used for statistical evaluation. RESULTS:A total of 95 patients, mean age 55.4 years, were included. A total of 31% of aneurysms were ruptured at admission. Most (58.3%) were located in the anterior circulation, and 45% had previous treatment, mainly coiling (69.4%). Complication rates were higher for ruptured aneurysms (24.1%) compared with unruptured ones (9.2%). Two deaths occurred, 1 (1.1%) related to the procedure. At discharge, 87% of patients had modified Rankin Scale ≤2. The latest follow-up showed overall complete/near-complete occlusion rates of 76.1%, with 81.14% for ruptured and 73.43% for unruptured aneurysms. Technical success was higher in unruptured cases (100% vs 93.1%). CONCLUSION/CONCLUSIONS:Our case series demonstrated the efficacy of the SVB with a high rate of technical success. The occlusion rates for ruptured cases are comparable with those of other FDs. However, the rates are lower for unruptured cases. This discrepancy is likely due to the characteristics of the aneurysms, particularly in the presence of side branches in bifurcation lesions. The SVB safety profile is similar to other FDs in unruptured cases, while the ruptured group presented more complications.

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.

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. .

BACKGROUND:The Drivewire 24 (DW24) is a newly FDA-cleared 0.024 inch steerable guidewire. Its proximally controlled deflectable tip allows for intravascular steering to facilitate selective navigation of diagnostic or therapeutic catheters. We present the first clinical experience with the DW24. METHODS:All neurointerventional procedures using the DW24 from October 2024 to April 2025 were retrospectively reviewed. Indications, procedural details, DW24 performance, wire-related complications, and operator feedback were assessed. RESULTS:27 procedures were performed utilizing the DW24. Indications included aneurysm (n=16), stroke (n=5), arteriovenous fistula or malformation (n=4), and diagnostic venography (n=2). Technical success was achieved in 92.6% of cases. Target vessels included the MCA, anterior cerebral artery, posterior cerebral artery, internal carotid artery segments, transverse sinus, and torcula. The device's radiopaque, hydrophilic distal tip aided fluoroscopic visibility, and the variable support enabled articulation across a range of aspiration and delivery catheters without requiring additional support devices. The DW24's steerability enabled access to challenging cerebrovascular anatomy, including one stroke case where conventional guidewires failed to reach a distal M2 occlusion. The DW24's intravascular steering also allowed for the delivery of catheters for Pipeline Embolization Device (PED) deployment and facilitated PED post-processing to improve wall apposition without requiring wire removal, reshaping, or balloon angioplasty. Operators observed a short learning curve. There were no device-related complications, though the wire's response to rotational force was a limitation. CONCLUSION/CONCLUSIONS:The DW24 demonstrated a high technical success rate with no device-related complications. Its versatility across catheter sizes and precise controllability facilitate navigating complex cerebrovasculature. Further studies should assess efficacy in larger cohorts across additional clinical scenarios.

BACKGROUND AND OBJECTIVES/OBJECTIVE:Iatrogenic cerebrovascular injury can cause intracranial hemorrhage and pseudoaneurysm formation, putting patients at high risk for postoperative bleeding. No consensus for management exists. This study describes endovascular treatment of these acute injuries with flow diverter stents. METHODS:Electronic medical records were retrospectively reviewed for injury type and etiology, timing of diagnosis, and endovascular management, including antiplatelet regimens, embolization results, and clinical outcome. RESULTS:Six patients were included. Three suffered an injury to the internal carotid artery, 1 suffered an injury to the left anterior cerebral artery, 1 suffered an injury to the right posterior cerebral artery, and 1 suffered an injury to the basilar artery. Four of the 6 injuries occurred during attempted tumor resection, 1 occurred during cerebrospinal fluid leak repair, and 1 occurred during an ophthalmic artery aneurysm clipping. All injuries resulted in pseudoaneurysm formation. Four were immediately detected on angiography; 2 were initially negative on imaging. Five were treated with a pipeline embolization device, and 1 was treated with a Silk Vista Baby. Two were treated with 2 pipeline embolization devices telescopically overlapped across the pseudoaneurysm. All devices deployed successfully. No pseudoaneurysm recurrence or rebleeding occurred. No parent artery occlusion or stenosis was observed, and complete pseudoaneurysm occlusion was observed in 4 patients (in 2 patients, follow-up imaging could not be obtained). CONCLUSION/CONCLUSIONS:With proper antiplatelet regimens, flow diverter stents can be used safely to successfully treat complex acute iatrogenic injuries. Early repeat angiogram is needed when immediate postinjury imaging does not discover the point of vessel injury.

Tethered postoperative drains are not uncommon complications that often require open removal in the operating room, which can increase risks of surgical site infection as well as length of hospitalization. We present a novel method of tethered drain removal through guidewire electrification. A retained deep drain following a posterior cervical laminectomy and fusion was identified after failed manual removal. Under fluoroscopic guidance, the retaining suture was indirectly identified through the obstruction of an inserted guidewire, through which monopolar cautery was applied, breaking the suture and allowing drain removal. The original incision did not need to be re-opened. While further investigation is necessary for validation, this technique shows great promise as an alternative to open removal.

BACKGROUND:Intravenous thrombolysis (IVT), utilizing the clot-dissolving medications alteplase (rt-PA) or tenecteplase (TNK), is the cornerstone in acute ischemic stroke (AIS) emergency intervention. However, the impact of prior antiplatelet therapy (APT) on post-IVT outcomes when utilizing alteplase remains controversial. We conducted a systematic review and meta-analysis to evaluate the effect of prior APT on the outcomes after using alteplase in AIS patients. METHODS:We conducted a systematic review and meta-analysis synthesizing studies, which were retrieved by systematically searching PubMed, Web of Science, SCOPUS, and Cochrane through June 30, 2024. We used the R language V. 4.3. to pool dichotomous data using odds ratio (OR) with a 95% confidence interval (CI). PROSPERO ID/UNASSIGNED:CRD42024495393. RESULTS:Thirty studies were included in our analysis, with 436,232 patients. Prior APT was significantly associated with increased odds of symptomatic intracranial hemorrhage (sICH) (OR, 1.78; 95%CI [1.48, 2.13]; P < 0.01), any ICH (OR, 1.44; 95%CI [1.16, 1.78]; P < 0.01), mortality (OR, 1.39; 95%CI [1.23, 1.58]; P < 0.01), and poor functional outcomes (modified Rankin Scale score of 3-6 [mRS 3-6]) (OR, 1.81; 95%CI [1.03, 3.19]; P = 0.04). Additionally, prior APT significantly reduced the odds of good functional outcome [mRS 0-2] (OR, 0.85; 95%CI [0.74, 0.97]; P = 0.02). CONCLUSION/CONCLUSIONS:Prior APT increased hemorrhagic complications, mortality, and poor functional outcome, while reducing the odds of good functional outcome after IV alteplase. Future research should focus on identifying adjunctive agents that may decrease hemorrhagic complications and investigate the impact of various APT regimens and alternative thrombolytics beyond alteplase in this specific population.