Faculty Bibliography

BACKGROUND AND OBJECTIVES/OBJECTIVE:Trans-sonolucent cranioplasty ultrasonography (TCUS) has been explored as a noninvasive tool for evaluating superficial temporal artery (STA)-middle cerebral artery (MCA) bypass patency. Previous research has focused on early postoperative feasibility. Data on its long-term utility and correlation with formal angiography remain scarce. We aimed to evaluate TCUS' role in postoperative STA-MCA bypass graft monitoring and its concordance with formal angiography. METHODS:This retrospective study included 46 consecutive direct STA-MCA anastomoses in 40 patients (March 2021-May 2024), all with sonolucent polymethyl methacrylate cranioplasty. Patient records were reviewed for demographics, disease and surgical characteristics, and outcomes. Postoperative TCUS was performed outpatient to monitor anastomotic patency. Formal follow-up angiography was also conducted, and radiographic data were reviewed for graft patency assessment and qualitative correlation with TCUS. RESULTS:Follow-up angiography was performed for 41 of 46 anastomoses (digital subtraction angiography, n = 34; computed tomography angiography, n = 4; magnetic resonance angiography, n = 3) at a median of 1.1 years, demonstrating 97.6% patency (40/41). Outpatient TCUS was performed in 32 of 46 bypasses (69.6%) with 100% patency at first scan (median 28.5 days). A second TCUS (n = 19, 41.3%) at a median of 8.4 months (3.9-13.6 months) showed robust flow in 94.7% of cases. One bypass had asymptomatic slow flow with a narrowed anastomosis, and another showed a severely stenosed STA correlating with later digital subtraction angiography. In the broader cohort, third (n = 5, median 1.2 years) and fourth (n = 1, 1.4 years) TCUS assessments demonstrated 100% patency. Among bypasses undergoing both TCUS and angiography (n = 31, 67.4%), findings were concordant in all cases. CONCLUSION/CONCLUSIONS:TCUS demonstrated complete agreement with formal angiography in assessing bypass patency, supporting TCUS as a reliable, noninvasive monitoring tool. Future research should explore quantitative TCUS flow measurements and their relationship to intraoperative flow and long-term graft remodeling.

BACKGROUND AND IMPORTANCE/BACKGROUND:Marfan syndrome's association with intracranial aneurysms, though controversial, poses unique challenges for surgical intervention because of the inherent vascular fragility. Open surgical approaches carry considerable risk. Endovascular flow diversion with the Pipeline embolization device (PED) offers a less invasive alternative, and adjunctive coiling can decrease occlusion time for complex aneurysms. We report the first combined use of PED and coiling to treat a Marfan-associated intracranial aneurysm, detailing our operative approach and reviewing the literature. CLINICAL PRESENTATION/METHODS:mutation was incidentally found to have an unruptured paraophthalmic aneurysm during stroke workup. Diagnostic angiography revealed an irregular superior hypophyseal aneurysm along with tortuous and irregular internal carotid arteries suggesting previous dissections. The aneurysm was successfully treated with a PED and adjunctive coil embolization. The patient was discharged on aspirin and clopidogrel. Six-month follow-up angiography confirmed aneurysm occlusion. Although there was no residual or recurrent aneurysm at 2-year follow-up, imaging revealed 2 de novo intracranial aneurysms. The patient remains asymptomatic and under observation. CONCLUSION/CONCLUSIONS:mutations and cerebrovascular pathology.

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.

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.

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.

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.

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: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.

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 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.