Faculty Bibliography

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:Carotid webs are an underrecognized cause of ischemic stroke in young adults and are associated with a high risk of recurrence when managed with medical therapy alone. Although carotid endarterectomy (CEA) is increasingly performed, histopathological confirmation remains infrequently reported, and the underlying pathological substrate of symptomatic carotid webs is not well defined. In this study, we present the largest pathologically confirmed series of symptomatic carotid webs treated with CEA, providing a comprehensive clinicopathological characterization and evaluation of long-term surgical outcomes. METHODS:Patients with symptomatic carotid webs were retrospectively identified from institutional databases encompassing both inpatient and outpatient encounters. Clinical features, imaging characteristics, surgical findings, and histopathological results from CEA specimens are presented. RESULTS:Among 39 patients with symptomatic carotid web, 34 underwent CEA with histopathological confirmation of the diagnosis, characterized by focal eccentric intimal fibromyxoid tissue, fibromuscular dysplasia, hyperplasia, or thickening. Notably, concurrent atheromatous changes were noted in 6 patients. All webs were located within 3 cm of the carotid bifurcation, and most (76%) were localized on the posterior wall. Competing stroke mechanisms were identified in 15% of patients. Two-thirds of patients presented with a large or medium vessel occlusion and over half received acute reperfusion therapy (intravenous thrombolysis and/or mechanical thrombectomy). Two patients experienced transient, minor cranial nerves injuries (hypoglossal nerve and marginal mandibular branch) after CEA. At a median follow-up of 29 months, no patients experienced recurrent stroke (95% CI: 0%-10%), and the median modified Rankin Scale score was 1 (0-1). CONCLUSION/CONCLUSIONS:This study supports CEA as a safe and effective therapeutic option for patients with symptomatic carotid webs and demonstrates its diagnostic value through direct histopathological confirmation. By presenting the largest pathologically validated series to date, our findings further define the vascular pathology underlying carotid webs and underscore the diagnostic value of surgical resection for definitive diagnosis.

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: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 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 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.

Despite continued advancement in thrombectomy devices and techniques, a small proportion, approximately 10%, of thrombectomy attempts result in failed reperfusion due to technical difficulties with reaching the clot or recanalizing the occluded vessel. Technically challenging thrombectomy cases are often longer, with more thrombectomy passes, resulting in poorer clinical outcomes and higher rates of complications. Factors causing difficulty during thrombectomy include tortuous vasculature preventing access, challenging clot location (tandem or distal occlusions), underlying vessel abnormality, and hard-to-retrieve clots. Anticipating potentially challenging or refractory thrombectomy cases allows one to plan appropriate procedural strategies with the goal of maximizing technical success and favorable clinical outcome. We review these challenging situations and discuss specific procedural techniques that can be employed in each scenario to overcome the barriers and achieve fast and successful reperfusion.

Carotid webs are increasingly recognized as an underdiagnosed etiology of ischemic stroke, especially in young, otherwise healthy patients. These fibrous intimal protrusions create regions of flow stasis within the internal carotid artery, predisposing to thromboembolism. Diagnosis remains challenging due to their subtle radiographic appearance and underappreciation in clinical practice. While antiplatelet therapy or anticoagulation used to be the cornerstone of management, medical therapy alone has been found to be insufficient for stroke prevention in symptomatic patients. Definitive intervention includes carotid artery stenting or carotid endarterectomy; both have demonstrated excellent safety and efficacy. Risk stratification for symptomatic and asymptomatic carotid webs remains an area of active research, with emerging evidence suggesting that specific anatomic features, termed the carotid web angioarchitecture, may help predict stroke risk. Further studies are needed to determine the role of preventative intervention. A deeper understanding of carotid web pathogenesis, natural history, and hemodynamic impact is critical for guiding clinical decision-making.