Objective: Flow-directed microcatheters (FDMs) offer high flexibility and trackability for accessing distal arterial feeders. However, the radiopaque tip marker is small, making it difficult to identify on fluoroscopy. This study evaluated an intraoperative artificial intelligence (AI)–based system for real-time detection of FDM tip markers.

Methods: We retrospectively analyzed 10 consecutive cases of middle meningeal artery embolization for chronic subdural hematoma using the AI-based system. The detection rate was evaluated on a frame-by-frame basis during microcatheter placement. Exploratory subgroup analyses were performed based on the catheter diameter (1.5 Fr vs. 1.3 Fr) and whether the microcatheter tip or guidewire tip advanced ahead during navigation.

Results: Twenty-five FDM placement scenes were analyzed. Mean microcatheter navigation time was 2.1 min. The precision, recall, and detection rate of the system were 95%, 51%, and 50%, respectively; the detection rate was calculated as the proportion of true-positive frames among all analyzed frames. Although this was an exploratory subgroup analysis, the detection rate appeared higher for the 1.5-Fr microcatheters than that for the 1.3-Fr microcatheters (78% vs. 46%; p = 0.006). Furthermore, the detection rate was significantly higher when the microcatheter tip advanced ahead of the guidewire tip than vice versa (65% vs. 43%; p = 0.002).

Conclusion: Although the detection rate was 50%, the AI system may help operators recognize the tip position when it becomes difficult to identify on fluoroscopy. Larger multicenter studies are required to validate these findings.

Objective: Periprocedural antithrombotic management in patients with non-valvular atrial fibrillation (NVAF) undergoing carotid artery stenting (CAS) remains controversial. Although dual antiplatelet therapy is the standard regimen for CAS, its combination with a direct oral anticoagulant (DOAC) as triple therapy increases bleeding risk. On the other hand, interruption of DOAC therapy may increase thromboembolic risk. We evaluated the clinical outcomes and feasibility of an uninterrupted dual antithrombotic therapy (DAT) strategy consisting of a DOAC and single antiplatelet therapy (SAPT).

Methods: We retrospectively reviewed a case series of 10 patients with NVAF treated between 2018 and 2025 who underwent CAS while continuing DOAC plus SAPT without interruption. In all cases, SAPT (clopidogrel, aspirin, or prasugrel) was initiated at least 2 weeks before the procedure. Platelet function was assessed using the VerifyNow system (Werfen, Bedford, MA, USA). We evaluated baseline clinical characteristics, antithrombotic regimens, platelet reactivity, procedural details, and periprocedural clinical outcomes.

Results: The mean CHA₂DS₂-VASc and HAS-BLED scores were 4.4 ± 1.4 and 3.8 ± 1.0, respectively. CAS was successfully performed in all patients. One patient with elevated P2Y12 reaction units required the temporary periprocedural addition of cilostazol. No periprocedural hemorrhagic or thromboembolic complications occurred during the periprocedural period or within 3 months after CAS.

Conclusion: Uninterrupted DAT with a DOAC and SAPT may be a feasible periprocedural management strategy for CAS in patients with NVAF, without the need for DOAC interruption or triple therapy.

Objective: A rare anatomical pattern exists in which a cortical vein courses vertically while running parallel to the supratentorial dura mater, enters the dura, and ultimately drains into the transverse sinus (TS). This structure is referred to as the supratentorial dural venous channel (SDVC). In this study, we retrospectively reviewed the imaging characteristics of SDVCs.

Methods: We consecutively included patients with brain tumors, ischemic disease, or vascular malformations who underwent CT venography (CTV) between January 2020 and October 2023. During the study period, CTV was performed in 223 patients (454 sides) using standardized protocols designed to detect SDVCs (97 males and 126 females; mean age, 55.9 years; range, 0–87 years).

Results: SDVCs were identified in 15 sides (3.3%) among 454 evaluated sides. As the SDVC enters the dura mater, continuity of the vessel often becomes indistinct; however, after the transition, the vein typically appears flattened. The draining cortical veins were classified into 4 types: the vein of Labbé (73%), the posterior temporal vein (27%), the occipital vein (27%), and the anterior temporal vein (13%). Sixty-seven percent of SDVCs drained into the lateral half of the TS, whereas 33% drained into the medial half. A characteristic notch on the inner table of the skull was observed at the dural entry point in 93% of cases.

Conclusion: The SDVC represents an important anatomical structure that should be carefully evaluated during craniotomy or endovascular procedures, and it can be reliably identified on CTV. The combination of transient venous indistinctness and inner table notching represents characteristic findings corresponding to the dura mater entry site.

Objective: Stent-assisted coil embolization (SAC) has expanded the treatment options for ruptured wide-neck aneurysms; however, SAC during the acute phase of subarachnoid hemorrhage (SAH) remains controversial owing to concerns regarding thromboembolic and hemorrhagic complications. This study aimed to evaluate the feasibility and safety of SAC for ruptured wide-neck aneurysms in the acute phase of SAH at a single center in Japan.

Methods: Patients with ruptured wide-neck aneurysms who underwent endovascular treatment within 48 h after SAH onset between January 2015 and December 2024 were retrospectively evaluated. Wide-neck aneurysms were defined as those with a neck width of ≥4 mm or a dome-to-neck ratio of <2. Patients were divided into 2 groups: the SAC group and the non-SAC group. The primary outcome was perioperative complications. Secondary outcomes included angiographic outcomes, clinical outcomes at discharge and 1-year follow-up, and retreatment rates.

Results: A total of 140 patients were included (SAC group, n = 24; non-SAC group, n = 116). Aneurysms in the SAC group demonstrated more complex morphology, particularly lower aneurysm height and smaller dome-to-neck ratios. The rates of perioperative hemorrhagic complications (12.5% vs. 9.4%) and symptomatic thromboembolic complications (8.3% vs. 8.6%) were comparable between the SAC and non-SAC groups. The immediate angiographic outcomes did not differ significantly between the 2 groups. Clinical outcomes at discharge and at 1-year follow-up did not differ significantly.

Conclusion: SAC for ruptured wide-neck aneurysms in the acute phase of SAH appears to be feasible with no significant differences in perioperative complication rates or clinical outcomes compared with non-SAC treatment. With appropriate patient selection and careful antiplatelet management, SAC may be a reasonable treatment option.

Objective: Wrist-based access for cervicocerebral angiography and neurovascular interventions is increasingly adopted as an alternative to transfemoral access, offering lower complication rates and faster recovery. In select cases, dual arterial access facilitates navigation of complex anatomy and the use of multiple devices. However, evidence supporting bilateral wrist access remains limited. We report our institutional experience (University of Pennsylvania Health System) with this approach.

Methods: We retrospectively reviewed consecutive diagnostic and interventional neurovascular procedures performed using bilateral wrist access across a single university health system (September 2019–July 2025). Demographic, clinical, and procedural data were summarized, with a focus on technical considerations and outcomes.

Results: Twenty procedures were performed, including 7 diagnostic and 13 interventional cases. Bilateral radial access was used in 16 cases, and ulnar access in 4. Median procedure time was 117 min for diagnostic cases and 236 min for interventional cases. The most common indication for bilateral access in diagnostic procedures was to facilitate anatomic reach for vertebral artery catheterization, while a transcirculation approach was the primary indication in interventional cases. Target vessel catheterization was achieved in 19 of 20 cases (95%). No major complications occurred. One case required conversion to femoral access due to unfavorable working angles across the aortic arch. One self-limited radial artery wire microperforation was successfully managed with catheter tamponade and conversion to ulnar access. On systematic review of follow-up imaging, 1 symptomatic radial artery occlusion was identified (1/20; 5%), managed conservatively without functional sequelae; no other access-site complications were observed.

Conclusion: Bilateral wrist access is a safe and technically feasible alternative access strategy in carefully selected cases for cervicocerebral angiography and neurovascular interventions. With appropriate planning, this technique may serve as a selective alternative access strategy for complex procedures requiring dual arterial access, particularly posterior circulation and transcirculation interventions.

Objective: This Woven EndoBridge Database (W-EB DB) study was conducted using data from a nationwide, multicenter database to evaluate the safety and efficacy of the W-EB device (MicroVention, Aliso Viejo, CA, USA; distributed by Terumo, Tokyo, Japan) for the treatment of wide-neck intracranial bifurcation aneurysms in Japanese patients. In this paper, we confirm the clinical usefulness of the W-EB device in Japanese patients based on the comparable 1-year post-procedure outcomes to those reported from overseas.

Methods: This W-EB DB study was a post-marketing, open-label, non-randomized cohort study conducted using the database of the Japanese Society of Neuroendovascular Therapy (JSNET). A total of 128 participants (including 103 patients with unruptured aneurysms and 25 patients with ruptured aneurysms) treated with the W-EB device between December 2020 and December 2025 at any of the 12 participating centers were included in this study. Clinical data collected from the database consisted of the patient demographics, comorbidities, aneurysm characteristics (location, size, and neck width), procedural details, and follow-up outcomes. The safety endpoints were the incidences of subarachnoid hemorrhage (SAH), rebleeding, cerebral infarction, and other adverse events occurring within 1 year after the procedure. The efficacy endpoints were the aneurysm occlusion rates and retreatment rates at 180 days and 1 year after the procedure; the aneurysm occlusion status was determined in accordance with the W-EB Occlusion Scale (WOS). We used descriptive statistics to analyze the results. The research within our submission was approved by the institutional ethics review board of Kyoto University (Approval No. R2088).

Results: In regard to the safety endpoints, SAH occurred in 1 patient (1.0%) with an unruptured aneurysm, and rebleeding occurred in 1 patient (4.0%) with a ruptured aneurysm. The incidence of cerebral infarction was 7.0%. Most other adverse events were mild, and no new device-related risks were identified. In regard to the efficacy of the device, at 1 year post-procedure, complete occlusion (WOS grade A or B) was achieved in 58 of 95 lesions (61.1%) and adequate occlusion (WOS grade A, B, or C) was achieved in 79 of 95 lesions (83.2%). Retreatment was needed for 5 of 126 lesions (4.0%). The safety and efficacy outcomes were comparable to those reported from multicenter studies conducted in Europe and the United States, with slightly higher complete occlusion rates and similar adequate occlusion and retreatment rates.

Conclusion: Favorable safety and effectiveness of the W-EB device were observed at 1 year after device deployment in Japanese patients with wide-neck intracranial aneurysms. These findings are consistent with international reports and support the clinical utility of the W-EB device, given the low incidence of serious complications.

Objective: Futile recanalization (FR) is defined as a poor functional outcome despite successful reperfusion after mechanical thrombectomy (MT) and remains a clinical concern in acute ischemic stroke. This study investigated clinical predictors of FR in patients with middle cerebral artery (MCA) M2 occlusion.

Methods: This single-center retrospective study included consecutive patients with acute cardioembolic stroke due to MCA M2 occlusion who underwent MT between April 2021 and December 2025. We included patients with successful reperfusion (modified Thrombolysis in Cerebral Infarction score ≥2b), and a pre-stroke modified Rankin Scale (mRS) score of 0–2. FR was defined as mRS 3–6 at discharge. We compared clinical, procedural, and outcome variables between patients with FR and those with effective recanalization (mRS 0–2). Multivariable logistic regression analysis adjusted for age and sex was performed to identify independent predictors of FR. A potential cutoff for receiver-operating characteristic (ROC) analysis was determined using the Youden index.

Results: Participants comprised 30 patients (median age, 79 years; 56.7% men), with FR identified in 13 patients (43.3%). Patients in the FR group showed a higher baseline National Institutes of Health Stroke Scale (NIHSS) score than those in the effective recanalization group (median 19 vs. 10; p <0.01). In multivariable analysis, the NIHSS score was independently associated with FR (odds ratio, 1.18; 95% confidence interval, 1.01–1.39; p = 0.044). ROC analysis showed an area under the curve of 0.76, and an NIHSS score of 11 was identified as a potential cutoff for predicting FR. Procedural variables, including puncture-to-recanalization time, did not remain significant after adjustment. No significant differences in anatomical characteristics of M2 occlusion were observed between groups.

Conclusion: A higher baseline NIHSS score may be associated with FR after MT in patients with MCA M2 occlusion. An NIHSS score of 11 may serve as a practical reference for risk stratification, although these findings should be considered exploratory. Baseline neurological severity may have a greater influence on clinical outcome than procedural factors after successful recanalization.

Objective: Carotid artery stenting (CAS) using a distal balloon protection device (DBPD), which had been widely used in Japan, became difficult to perform after the discontinuation of the PercuSurge GuardWire (Medtronic, Minneapolis, MN, USA) in April 2021. The Protcas GW protection device (SB-KAWASUMI LABORATORIES, Kanagawa, Japan) was subsequently developed as a new DBPD; however, its clinical use has not yet been reported. In this study, we describe our initial clinical experience with the Protcas GW and evaluate its efficacy and safety in real-world practice.

Methods: We retrospectively analyzed consecutive patients who underwent CAS using the Protcas GW between April 15, 2025 and August 31, 2025 at a single center in Japan. Patient demographics, characteristics of the stenotic lesions, and procedural details were collected. Clinical outcomes included technical success, device-related adverse events, and the composite of any stroke, myocardial infarction, or death during the periprocedural period.

Results: A total of 10 patients were included. The median age was 76 years (interquartile range [IQR], 75–84), and the cohort consisted of 9 men and 1 woman. Eight patients had symptomatic stenosis. The median North American Symptomatic Carotid Endarterectomy Trial (NASCET) stenosis severity was 56.5% (IQR, 52.3–65.3), and unstable plaque was identified in 5 cases. The median plaque length was 18.5 mm (IQR, 15–23.8 mm). CAS using the Protcas GW was successful in all cases. One case required device replacement due to inadequate distal balloon inflation; no other device-related adverse events were observed. No periprocedural events occurred in the composite outcome of any stroke, myocardial infarction, or death. Asymptomatic diffusion-weighted imaging-positive lesions were detected in 3 cases on postoperative MRI, with lesion counts of 1, 1, and 2, respectively.

Conclusion: In this initial clinical experience, CAS performed using the Protcas GW device was completed successfully without major device-related adverse events, indicating that the procedure can be performed safely.

Objective: This study aimed to evaluate the feasibility and safety of a computer-controlled local anesthetic delivery device during transradial cerebral angiography and to descriptively assess procedural pain and hemodynamic changes in an initial series of patients.

Methods: In this prospective pilot study, 10 consecutive adult patients undergoing elective diagnostic cerebral angiography via the radial artery received local anesthesia with a computer-controlled injection device using 1 mL of 3% mepivacaine delivered through a 33-G needle. The primary outcome of this study was feasibility, defined as successful delivery of local anesthesia and completion of transradial access without device-related complications or the need to convert to manual injection. Secondary outcomes included pain intensity assessed using a 0–100-mm visual analogue scale (VAS) at predefined procedural steps, hemodynamic changes before and after sheath insertion, and access-site adverse events such as vasospasm or bleeding. Blood pressure was compared between baseline (immediately before local anesthesia) and after sheath insertion.

Results: All 10 procedures were successfully completed using the computer-controlled device without device malfunction, conversion to manual injection, or access failure. The first puncture attempt was successful in all patients. The median VAS score following local anesthesia was 18 [13–22] mm, following arterial puncture was 3 [2–4.75] mm, and following sheath insertion was 7.5 [3–10] mm. There was no significant difference in median systolic blood pressure before local anesthesia and after sheath insertion (160.7 ± 30.6 vs. 160.1 ± 27.6 mmHg; p = 0.84), and diastolic blood pressure also did not change significantly (80.5 ± 6.2 vs. 77.5 ± 10.0 mmHg; p = 0.16). No clinically evident radial artery spasm or hemorrhagic access-site complications occurred.

Conclusion: In this pilot study, computer-controlled local anesthesia during transradial cerebral angiography was feasible and appeared safe in a small cohort of patients. Pain-related findings should be interpreted as descriptive and hypothesis-generating, and further controlled studies are required to evaluate efficacy.

Objective: The CASPER stent (Terumo, Tokyo, Japan) is a dual-layer micromesh device designed to prevent plaque prolapse into the stent struts and reduce perioperative stroke risk. However, the in-stent restenosis (ISR) incidence and associated factors after CASPER placement in Japan remain insufficiently investigated. This study aimed to evaluate the ISR rate, timing, and associated factors after CASPER placement.

Methods: Eighty consecutive patients who underwent carotid artery stenting with a CASPER stent at a single institution between March 2021 and December 2023 were retrospectively analyzed. Preprocedural plaque characteristics, procedural details, and follow-up carotid artery ultrasound findings were reviewed. ISR was defined as luminal narrowing ≥50% in patients with neurological symptoms attributable to the ISR lesion and ≥70% in patients without such symptoms.

Results: Over a mean follow-up of 27.6 ± 9.9 months, ISR occurred in 10 patients (12.5%). ISR developed 1.8–16.4 months after the index procedure, with a median time of 8.5 months. Patients with ISR had lower plaque-to-muscle ratio (PMR) values on T1-weighted MRI than patients without ISR (1.45 vs. 1.90, p = 0.024). Furthermore, stent diameter was smaller in patients with ISR than in those without it (median 7.5 vs. 8.0 mm, p = 0.029). During follow-up beyond 30 days after stent placement, ipsilateral ischemic stroke tended to occur more frequently in patients with ISR than in those without it (20.0% vs. 2.9%, p = 0.056).

Conclusion: In patients treated with CASPER, ISR occurred within the first 18 months after treatment. Lower PMR values and smaller stent diameters were associated with ISR in this cohort. Larger studies with long-term follow-up are required to confirm these findings and assess CASPER stent long-term outcomes.

Objective: Rapid reperfusion is essential in acute ischemic stroke (AIS). The Saitama Stroke Network (SSN) facilitates the direct transfer of mechanical thrombectomy (MT) candidates to MT-capable hospitals. However, some candidates are misclassified and transferred to a general emergency department, delaying treatment. To address this, we implemented an “in-hospital stroke bypass” system. In this system, emergency medical technicians (EMTs) in the emergency department perform the emergent large vessel occlusion (ELVO) screen and directly activate the MT team, bypassing emergency physicians. This study aimed to evaluate the effectiveness of an in-hospital stroke bypass system in reducing treatment delays in patients with AIS who were initially transported as general emergency cases.

Methods: We retrospectively analyzed 140 consecutive patients with AIS who underwent emergent endovascular reperfusion therapy between December 2019 and December 2021. Patients were categorized into the SSN group (n = 94), stroke bypass (SB; n = 17) group, or non-SB (n = 29) group. Baseline characteristics, door-to-puncture (D2P) and door-to-reperfusion (D2R) times, angiographic results, and modified Rankin Scale (mRS) scores at 90 days were compared among the groups.

Results: Baseline demographics were similar among the groups; however, baseline National Institutes of Health Stroke Scale scores differed significantly among the 3 groups: 21 (15–26), 25 (21–28), and 27 (12–35) in SSN, SB, and non-SB groups, respectively (p = 0.04), although no significant differences were observed in post hoc pairwise comparisons. Median D2P times were 50 (38–65), 56 (50–69), and 133 (94–196) min in SSN, SB, and non-SB groups, respectively; median D2R times were 108 (80–145), 125 (98–150), and 217 (166–270) min in SSN, SB, and non-SB groups, respectively. Both times were significantly longer in the non-SB group (p <0.01). Successful reperfusion (modified thrombolysis in cerebral infarction [mTICI] grade 2b–3) occurred in approximately 75% of the patients in all groups. Functional independence (mRS 0–2 at 90 days) was achieved in 41.5% (SSN), 23.5% (SB), and 27.6% (non-SB) of patients, with no significant differences observed. Coma and the absence of conjugate gaze deviation were associated with in-hospital stroke bypass failure.

Conclusion: In-hospital stroke bypass conducted by trained EMTs has effectively reduced the treatment times for MT patients who were previously overlooked, bringing them in line with the treatment times of those transferred via SSN. Establishing refined prehospital criteria for comatose patients without gaze deviation may further enhance early identification and timely reperfusion therapy.

Objective: N-butyl cyanoacrylate (NBCA) must reach the venous side beyond the fistulous point (venous penetration) for the successful transarterial embolization of dural arteriovenous fistulas (DAVFs). The purpose of this study is to identify several factors associated with the venous penetration of NBCA.

Methods: One hundred and thirty-four transarterial embolization procedures using an NBCA–lipiodol mixture (NBCA–Lip) in 38 consecutive patients with DAVFs treated at Kumamoto University Hospital were reviewed. DSA images before, during, and after the injection of NBCA–Lip, as well as procedure records, were reviewed with particular interest in the venous penetration of NBCA–Lip and factors potentially associated with the venous penetration, including volume rates of NBCA–Lip, artery injected, types of feeding artery injected (proper feeder or proximal feeder), status of injection (wedged or non-wedged), position of a microcatheter in relation to the sharp bend of the feeder, and use of adjunctive techniques. The correlation between venous penetration of NBCA–Lip with these factors was statistically analyzed using XLSTAT software (Lumina Decision Systems, Campbell, CA, USA).

Results: Among 134 NBCA–Lip injections, venous penetration was achieved in 68 injections (50.7%) and was significantly associated with injection from the proper feeder (odds ratio [OR], 11.9; 95% confidence interval [CI], 4.6–31.3; p <0.001), wedged injection (OR, 5.6; 95% CI, 2.6–11.9; p <0.001), injection in the non-curved position (OR, 15.9; 95% CI, 6.8–36.9; p <0.001), and injection with adjunctive techniques (OR, 2.1; 95% CI, 1.0–4.4; p = 0.04). Multivariate logistic regression analysis showed that wedged injection (OR, 8.8; 95% CI, 3.0–26.0; p <0.001) and injection in the non-curved position (OR, 25.0; 95% CI, 9.1–100.0; p <0.001) independently predicted venous penetration.

Conclusion: The venous penetration of injected NBCA–Lip is significantly affected by the position and status of the microcatheter tip.

Objective: Accurate assessment of a patient’s skin dose during interventional radiology (IVR) for spinal vascular lesions is challenging, particularly when the upper arms are positioned within the irradiation field. This study aimed to quantify the discrepancy between system-displayed dose values and actual skin dose, while assessing the impact of C-arm angulation on patient skin dose during spinal IVR.

Methods: Dosimetric measurements were performed using an adult anthropomorphic phantom. A 0.6-cc CT ionization chamber was positioned on the phantom surface at the center of the lateral C-arm irradiation field. Fluoroscopic irradiation was performed for 1 min at right anterior oblique (RAO) angulations ranging from 40° to 120° in 10° increments using a biplane angiography system. The measured skin dose was compared against the system-displayed reference air kerma at the patient reference point. Measurements were performed in triplicate and evaluated across 3 anatomical regions: the upper thoracic region (including the upper arms), lower thoracic region (excluding the upper arms), and lumbar region. Air kerma was used as a surrogate for skin dose.

Results: The measured skin dose exceeded the system-displayed dose in all anatomical regions, with the most significant discrepancy observed in the upper thoracic region. At RAO 90°, which corresponds to a true lateral projection, the measured skin dose in the upper thoracic region was 1.68 times higher than the system-displayed dose. Conversely, smaller discrepancies were observed in the lower thoracic and lumbar regions, and the measured doses were 1.17 and 1.18 times higher than the displayed values, respectively. Modifying the C-arm angulation by 20° from RAO 90° significantly reduced the measured skin dose in the upper thoracic region, with reductions of 77.9% and 85.4% at RAO 70° and 110°, respectively. However, even with these optimizations, the measured skin dose remained 1.42 times higher than the system-displayed dose.

Conclusion: During spinal IVR, particularly in the lateral projections of the upper thoracic spine, system-displayed dose may substantially underestimate actual patient skin dose when the upper arms are included within the irradiation field. This discrepancy likely reflects increased X-ray tube output driven by automatic dose control in response to elevated tissue attenuation. Optimizing the C-arm angulation represents a practical and effective strategy for reducing patient skin dose in this anatomically challenging region.

Objective: Mechanical thrombectomy (MT) is an established treatment for acute ischemic stroke due to large vessel occlusion. Although achieving first-pass effect (FPE) is strongly associated with clinical outcomes, branching-site occlusions remain technically challenging and are associated with lower FPE rates. The dual stent retriever (DSR) technique has been proposed to improve thrombus engagement in branching vessel anatomy. This study aimed to evaluate the efficacy and safety of the DSR technique in patients with branching-site occlusions.

Methods: We retrospectively reviewed consecutive patients with angiographically confirmed branching-site occlusions who underwent MT between January 2020 and April 2025. Patients were classified according to the first-line thrombectomy strategy into a DSR group or a single SR (SSR) group. We compared the FPE rate, procedural complications, and prognosis between the groups. Furthermore, an adjusted analysis was performed using Firth’s penalized logistic regression.

Results: Among 105 eligible patients, 20 were treated with the DSR technique. The rate of FPE was significantly higher in the DSR group than in the SSR group (90.0% vs. 27.1%, p <0.001), whereas procedure time and complications did not differ between groups. After adjustment for relevant confounders, the DSR technique remained independently associated with FPE (adjusted odds ratio [aOR] 38.92, 95% confidence interval [CI] 4.60–329.39, p <0.001) and favorable functional outcome (aOR 4.59, 95% CI 1.03–20.36, p = 0.045).

Conclusion: The DSR technique showed an association with higher rates of first-pass reperfusion in branching-site occlusions without a clear increase in procedural risk, indicating that it may be a feasible option in selected cases, although confirmation in prospective studies is needed.

Objective: Flow diverters (FDs) are widely used to treat intracranial aneurysms, with DSA serving as the gold standard for follow-up evaluation. Although a few studies have reported the use of photon-counting detector CTA (PCD-CTA) for minimally invasive follow-up after standalone FD treatment, PCD-CTA after coil-assisted FD placement has never been documented.

Methods: We retrospectively analyzed 11 patients who underwent FD placement between May 2023 and December 2024, all of whom underwent post-procedural evaluation with PCD-CTA. Patients were categorized into 2 groups: standalone FD (n = 6) and coil-assisted FD (n = 5). PCD-CTA was performed on postoperative day 1, at 6 months, and at 12 months. Metal artifact reduction was applied in the coil-assisted group.

Results: In the standalone FD group, PCD-CTA enabled reliable assessment of the in-stent lumen, FD apposition to the parent artery, and aneurysm occlusion, with findings consistent with those of DSA. In the coil-assisted FD group, when coils extended near the FD, evaluation of the in-stent lumen, FD-to-parent artery apposition, and aneurysm occlusion was hindered by metal artifacts in slices containing coils. Conversely, when coils were absent near the FD, partial visualization of intra-aneurysmal contrast was possible, although residual aneurysms tended to be underestimated.

Conclusion: PCD-CTA demonstrated diagnostic performance comparable to that of DSA for postoperative evaluation following standalone FD placement. However, in coil-assisted FD cases, postoperative assessment remained limited by coil-related metal artifacts.

Objective: This study aimed to improve the accuracy of luminal evaluation of flow diverters (FDs) using non-contrast-enhanced 3D time-of-flight MRA (3D-TOF-MRA).

Methods: The Flow-Redirection Endoluminal Device (FRED) and Pipeline Flex Embolization Device with Shield Technology (Pipeline) were deployed in phantom vessels with an inner diameter of 4 mm, and a phantom vessel without an FD was used as the reference. A diluted Gd contrast agent, adjusted to achieve a T1 relaxation time equivalent to that of blood, was circulated through the phantom vessels under steady flow conditions. Non-contrast-enhanced 3D-TOF-MRA images were acquired with varying echo time (TE), flip angle (FA), and Tilted Optimized Non-Saturating Excitation (TONE) ramp settings. Source images obtained from the central and edge regions of the stents were used to evaluate the relative in-stent signal (RIS) and lumen area ratio. In addition, the signal difference between the inflow and outflow regions was calculated and assessed as the saturation ratio.

Results: RIS values for both FRED and Pipeline decreased with increasing TE at both the central and edge regions. A similar decreasing trend was observed for the area ratio. Overall, FRED demonstrated relatively higher RIS and area ratio values than Pipeline. Regarding the FA variation, the peak RIS at the center regions occurred at an FA of 35° for both FDs, followed by a plateau. In the TONE ramp analysis, a setting of 30% yielded a saturation ratio closest to 100%.

Conclusion: These findings suggest that luminal visualization of FDs can be improved by optimizing 3D-TOF-MRA acquisition parameters, particularly the TE, FA, and TONE ramp settings.

Objective: The use of an 8-French (Fr) balloon guide catheter (BGC) for carotid artery stenting (CAS) using a transradial approach (TRA) has been limited by the small size of the radial artery (RA) and anatomical challenges, including difficulties with catheter navigation and concerns regarding device slippage. This study aimed to evaluate the technical feasibility and safety of TRA-CAS using an 8-Fr BGC.

Methods: We retrospectively reviewed consecutive patients who underwent TRA-CAS with an 8-Fr BGC (Emboguard [Cerenovus, Galway, Ireland], Flowgate2 [Stryker Neurovascular, Fremont, CA, USA], Optimo EPD FLEX [Tokai Medical Products, Aichi, Japan], or Branchor XS/XF [Asahi Intecc, Aichi, Japan]). Introduction of the BGC was performed with either a sheath-based or sheathless approach, selected at the discretion of the operator. Considering the outer diameter of the 8-Fr BGCs, the eligibility criteria included RA diameter ≥2.8 mm on vascular ultrasonography and a waveform other than type D by the BARBEAU test. Patient demographics and procedural and clinical outcomes at 90 days or later were evaluated.

Results: Twenty-one CAS procedures were attempted using an 8-Fr BGC via the TRA; 19 (90.5%) procedures were planned via the conventional RA and 2 (9.5%) via the distal RA. The lesion side was the right side in 14 patients (66.7%) and the left side in 7 (33.3%). Radial access success was achieved in 20 of 21 cases (95.2%); the remaining case required conversion to a transbrachial approach due to access site hematoma. Among the 20 cases with successful radial access, CAS was completed via the TRA/transdistal radial approach without conversion (technical success, 100%). BGC prolapse toward the aortic arch was observed in 6 cases. Balloon inflation was performed to stabilize the BGC in all cases. In 1 of these 6 cases, turnover of the BGC at the aortic valve was additionally required due to prolapse into the aortic arch. One case required device exchange due to BGC kinking. RA occlusion occurred in 1 case (4.8%), with no major complications.

Conclusion: CAS via TRA with an 8-Fr BGC appears feasible and safe in patients with RA diameter ≥2.8 mm, and the balloon properties may improve stability under conditions of challenging anatomy, making this a valuable option for carotid revascularization.

Objective: Mechanical thrombectomy (MT) is currently the standard treatment for large vessel occlusion (LVO). However, advancing a microcatheter and microguidewire into non-visualized distal vessels carries a risk of vascular perforation, potentially resulting in serious hemorrhagic complications. This study aimed to evaluate the usefulness of a new imaging protocol using single-phase CTA guided by the time-enhancement curve (TEC) derived from CT perfusion (CTP) in patients with anterior circulation LVO undergoing MT, for improving distal vessel visualization compared with conventional CTA using a bolus-tracking (BT) method.

Methods: Patients with anterior circulation LVO (intracranial internal carotid artery, M1 or proximal M2 segment of the middle cerebral artery) who underwent MT were retrospectively analyzed. The conventional BT-CTA protocol was used between October 2018 and June 2020, and a new CTP-derived TEC–guided CTA (TEC-CTA) protocol was used between July 2020 and August 2023. In the TEC-CTA protocol group, the scan timing of CTA was determined according to the TEC obtained from CTP to achieve optimal contrast filling of distal vessels. Visualization of vessels distal to the occlusion site was graded on a 4-point scale (0–3) and compared between the 2 protocols. Scores of 2 and 3 were considered useful for predicting the extent of thrombus and the vessel course. Additional outcomes included the puncture-to-recanalization time (PRT), thrombolysis in cerebral infarction (TICI) grade, complications, and modified Rankin Scale (mRS) score at 90 days.

Results: Sixteen and 46 patients underwent MT using the BT-CTA and TEC-CTA protocols, respectively. The incidence of well-visualized vessels overall (score of 2 or 3) was significantly higher in the TEC-CTA protocol group than in the BT-CTA protocol group (80.4% vs. 37.5%; p = 0.0033). The PRT was significantly shorter in the TEC-CTA protocol group than in the BT-CTA protocol group (44 vs. 58 min; p = 0.0134). The proportion of patients with TICI ≥2b after revascularization appeared to be higher using the TEC-CTA protocol (82.6% vs. 75.0%), but this was not significant. No intraprocedural vascular perforation occurred in either protocol, and no significant difference was observed in the frequency of intracranial hemorrhage between the protocols. The proportion of patients whose mRS score was ≤3 at 90 days after stroke onset was significantly higher in the TEC-CTA protocol group than in the BT-CTA protocol group (56.5% vs. 25%; p = 0.0424).

Conclusion: CTA performed with scan timing guided by CTP-derived TEC improves visualization of occluded vessels, contributing to safer and more effective MT.

Objective: Minimizing the time to reperfusion is a critical determinant of the prognosis of acute ischemic stroke (AIS). To reduce the workload of neurosurgeons, improve efficiency, and shorten the time required for AIS management delivered by the neurosurgical department, a nurse practitioner (NP) was introduced in April 2019. However, the effect of NP involvement on post-door-to-needle (D2N) intervals, particularly time to reperfusion, has not been clarified. This study examined whether NP participation was associated with shorter post-D2N time metrics in patients with AIS undergoing mechanical thrombectomy (MT).

Methods: This study included all consecutive patients with AIS due to intracranial large vessel occlusion who underwent MT between April 2019 and March 2024 at our institution. Patients with NP involvement were assigned to the NP group, and those without NP involvement were assigned to the non-NP group. NP participation was randomly determined according to their duty schedule. The primary outcomes were the median times from angiography suite entry-to-puncture (E2P) and from suite entry-to-recanalization (E2R). Secondary outcomes included onset-to-puncture (O2P), puncture-to-recanalization (P2R), door-to-entry (D2E), door-to-puncture (D2P), and the proportion of patients with a modified Rankin Scale (mRS) score of 0–2 at discharge. Statistical analyses included univariate and multivariate linear regression analysis, with significance set at p <0.05.

Results: In total, 115 patients were included: 44 in the NP group and 71 in the non-NP group. The baseline patient characteristics were comparable. The median E2P was significantly shorter in the NP group (15 vs. 21 min; p <0.05), representing a 6-min reduction (28.6%). The median E2R was 73 vs. 76.5 min, showing a nonsignificant 3.5-min decrease. Among the secondary metrics, D2P was shorter in the NP group, whereas the O2P, P2R, and D2E levels did not differ significantly. In the multivariate linear regression analyses, only E2P remained independently associated with NP involvement. The proportion of patients with favorable outcomes (mRS 0–2) at discharge was higher in the NP group (27.3% vs. 19.7%), although the difference was not significant.

Conclusion: NP participation significantly reduced E2P time. These findings suggest that NP involvement contributes to shortening the treatment time in the post-D2N phase and may have a crucial role in promoting efficient team-based care in AIS management.

Objective: Perfusion imaging is widely used in acute ischemic stroke to guide endovascular thrombectomy (EVT). This study evaluated clinical outcomes among patients selected for EVT using perfusion software-based analysis compared with those selected without it.

Methods: We conducted a retrospective comparative analysis of patients with large- or medium-vessel occlusion who underwent EVT between 2024 and 2025. Patients were categorized into a perfusion software group (RAPID implementation period) and a non-perfusion software group (non-RAPID period) based on the use of RAPID imaging software (iSchemaView, Menlo Park, CA, USA). The primary outcome was the proportion of patients achieving a good clinical outcome at 90 days, defined as a modified Rankin Scale (mRS) score of 0–3. Secondary outcomes included a shift analysis of mRS scores, procedural time metrics, all hemorrhagic events including symptomatic intracerebral hemorrhage (sICH), and 90-day mortality.

Results: A total of 54 patients were included (RAPID implementation period, 26; non-RAPID period, 28). At 90 days, the proportion of patients achieving a good outcome (mRS 0–3) was similar between the RAPID implementation period group and the non-RAPID period group (50.0% vs. 46.4%; P = 0.72). In the ordinal shift analysis of mRS scores, there was no significant difference in the overall distribution between groups (common odds ratio, 0.91; 90% confidence interval [CI], 0.41–1.99; P = 0.84). The median time from hospital arrival to groin puncture was also similar—45 min (interquartile range [IQR], 40–58) versus 46 min (IQR, 39–63; P = 0.96). The incidences of any intracerebral hemorrhage (30.8% vs. 32.1%), sICH (0% vs. 3.6%), and 90-day mortality (15.0% vs. 7.1%) were likewise comparable between the RAPID and non-RAPID periods.

Conclusion: These findings suggest that automated, perfusion-based patient selection enhances workflow standardization and can be seamlessly integrated into acute stroke management to optimize both speed and safety.

Objective: Stent-free coil embolization has advantages such as a low periprocedural risk and elimination of the need for antiplatelet therapy. Recent advancements in coil technology and adjunctive techniques, including the double-catheter method, may have contributed to improved outcomes. This study aimed to evaluate the safety, efficacy, and limitations of stent-free coil embolization for internal carotid–posterior communicating artery (IC-Pcom) aneurysms in current endovascular practice.

Methods: Between January 2017 and March 2024, 65 unruptured IC-Pcom aneurysms were initially treated with coil embolization at our institution. Of these, 58 cases without neck-bridging stents were analyzed. Final embolization status was assessed by follow-up MRA and classified according to the Raymond classification.

Results: The double-catheter coil embolization (DCC) was performed in 42 cases (72%). The mean follow-up duration was 42 months. Retreatment was required in 3 patients (5.2%), and 4 patients ultimately had residual aneurysms. Residual aneurysm was significantly associated with aneurysm size (dome, p = 0.033; height, p = 0.014; neck, p = 0.004) and postoperative embolization status (p = 0.002). Cutoff values predictive of residual aneurysm were: neck, 4.83 mm (area under the curve [AUC], 0.94; sensitivity, 1.0; specificity, 0.87); height, 5.35 mm (AUC, 0.88); and dome, 7.29 mm (AUC, 0.82). Complete obliteration was significantly associated with younger age (p = 0.042), absence of PcomA incorporation (p = 0.017), smaller PcomA diameter (p = 0.037), smaller aneurysm dimensions, and favorable embolization status (p <0.001). In multivariate analysis, a neck diameter <4.25 mm emerged as the sole independent predictor of complete obliteration (odds ratio, 6.33; 95% confidence interval, 1.27–31.4; p = 0.024).

Conclusion: Stent-free coil embolization achieved high rates of complete occlusion in aneurysms with a neck diameter <4.25 mm. However, despite the adoption of modern coils and advanced techniques such as the double-catheter method, larger aneurysms exceeding this cutoff may recur during midterm follow-up, underscoring the need for alternative treatment strategies.

Objective: Mechanical thrombectomy has become an established treatment for acute ischemic stroke caused by acute intracranial artery occlusion, but periprocedural complications may adversely affect outcomes. This study aimed to identify clinical and procedural factors associated with periprocedural complications following mechanical thrombectomy and to clarify their impact on prognosis.

Methods: We conducted a multicenter observational study of patients who underwent mechanical thrombectomy for acute intracranial artery occlusion between January 2016 and June 2022 across 11 stroke centers in Fukushima Prefecture, Japan. Data were collected from a retrospective registry (January 2016–December 2019) and a prospective registry (January 2020–June 2022). Periprocedural complications were defined as adverse events occurring during or within 24 h after the procedure, including hemorrhagic, ischemic, device-related, and extracranial complications. Univariate and multivariable logistic regression analyses were performed to identify independent predictors of periprocedural complications.

Results: A total of 487 patients were included in the analysis. Periprocedural complications occurred in 66 patients (13.6%). The most frequent procedure-related events were perforator injury (n = 18, 3.7%), vessel perforation (n = 9), and contrast-induced hemorrhage (n = 4). Post-procedural complications mainly included hemorrhagic transformation (n = 16). Compared with patients without complications, those with complications had a higher prevalence of atrial fibrillation (62.1% vs. 46.6%, p = 0.019), less frequent intravenous recombinant tissue plasminogen activator use (37.9% vs. 52.0%, p = 0.033), and longer puncture to recanalization time (76.5 vs. 57 min, p = 0.012). Symptomatic intracranial hemorrhage occurred exclusively in the complication group (31.8% vs. 0%, p <0.001). Patients with complications had a lower rate of favorable functional outcomes (modified Rankin Scale score 0–2 at 90 days, 18.2% vs. 42.6%, p <0.001). Multivariable analysis identified atrial fibrillation (odds ratio [OR] 1.885, 95% confidence interval [CI] 1.084–3.276, p = 0.025) and prolonged procedure time (per minute; OR 1.007, 95% CI 1.001–1.013, p = 0.017) as independent predictors of periprocedural complications.

Conclusion: Atrial fibrillation and longer procedure time were independently associated with periprocedural complications. Perforator injury and hemorrhagic transformation were major contributors to adverse events, with symptomatic intracranial hemorrhage leading to severe disability or death in most affected patients.

Objective: Treatment with flow diverters requires follow-up imaging. Conventional CT suffers from beam-hardening artifacts caused by the stent, complicating the evaluation. This study introduced the SOMATOM X.cite (Siemens Healthineers, Forchheim, Germany) scanner to improve imaging quality for stent follow-up and examined its image output (stent condition).

Methods: From January 2021 to April 2024, 27 patients treated with flow diverters were imaged using SOMATOM X.cite, conventional CT, and the ARTIS icono D-Spin system (Siemens Healthineers). The aneurysm locations included the internal carotid artery—specifically, 11 cases in the paraclinoid segment and 8 in the cavernous segment, as well as the vertebral artery in 8 patients. The aneurysm sizes were ≥10 mm (14 cases) and 5–10 mm (13 cases). The image quality of the stented parent artery was subjectively scored on a 2-point scale, adapted from a previous report in which a 3-point scale had originally been used, as follows: 1 = moderate (evaluation could be made but information was lacking compared with DSA), and 2 = good (image could be evaluated similarly to DSA).

Results: Compared with conventional contrast-enhanced CT, the SOMATOM X.cite significantly reduced beam-hardening artifacts around the stent. In 26 of 27 cases, stent-condition CT images acquired with the SOMATOM X.cite were rated as 2 (good), providing clear visualization of the stent lumen and similar in quality to cone-beam CT. One case had reduced contrast, making aneurysm visualization difficult. In comparison, 27 conventional CT images were rated 1 (moderate).

Conclusion: The SOMATOM X.cite scanner provided high-quality imaging comparable to cone-beam CT; thus, it may be a useful tool for follow-up evaluation after flow diverter stenting.

Objective: Intracranial arterial calcification (ICAC) has been suggested to influence the outcomes of mechanical thrombectomy (MT) for acute ischemic stroke. We conducted a systematic review and meta-analysis to evaluate MT outcomes in patients with acute ischemic stroke and large-vessel occlusions involving intracranial calcified arteries.

Methods: This study followed the Cochrane and Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. Peer-reviewed studies were included if they evaluated intracranial arterial calcification (≥130 Hounsfield unit [HU] on noncontrast computed tomography) in patients undergoing MT within 24 h of acute ischemic stroke and reported modified Rankin Scale (mRS) score at 90 days or the final thrombolysis in cerebral infarction (TICI) grade. Four databases (PubMed, Cochrane Library, Web of Science, and Embase) were searched from inception to July 2025. Two reviewers independently screened and extracted the data and assessed their quality using the Newcastle–Ottawa Scale. Odds ratios (OR) were pooled using Mantel–Haenszel random-effects models, and heterogeneity was assessed using I².

Results: Among 968 records, 4 observational studies (n = 832; 2016–2024) met the inclusion criteria. All were adjusted for baseline factors using multivariable or propensity score models. The quality of the studies ranged from moderate to high. The ICAC definitions varied as follows: morphological (intimal vs. medial), location-based (symptomatic vs. asymptomatic), or volumetric assessments. Meta-analysis showed that ICAC—particularly in studies distinguishing intimal from medial calcification—was significantly associated with poor 90-day outcomes (mRS 3–6) (pooled OR 1.74; 95% CI 1.21–2.52; p <0.001; I² = 49%). In a subanalysis focusing on calcification volume, increased volume alone was not consistently associated with worse functional outcomes or lower reperfusion success (pooled OR ≈ 1.19; 95% CI 0.78–1.80). Collectively, the lack of association in the volume-based analysis and the significant association observed in studies incorporating intimal–medial differentiation suggest that lesion morphology—particularly the presence of intimal calcification—may exert a greater influence on MT outcomes than calcification volume itself.

Conclusion: ICAC, especially when intimal calcification is present, is independently associated with procedural complexity and poor functional outcomes after thrombectomy for acute ischemic stroke. The divergent findings between the volume subanalysis and the broader morphology-based analysis highlight that morphology-driven, rather than volume-driven, calcification better explains outcome variability. Recognition of ICAC on baseline imaging may aid in prognostication, guide device strategies, and anticipate adjunctive interventions. Standardized assessments and prospective validation studies are needed to optimize outcomes.

Objective: While degenerative disorders are the typical cause of cervical radiculopathy, vascular etiologies are exceedingly rare. Dural arteriovenous fistulas (dAVFs) in the anterior condylar confluence (ACC) generally manifest with cranial neuropathies or pulsatile tinnitus. This report presents a unique case of ACC dAVF producing an epidural venous varix and cervical radiculopathy and describes the staged therapeutic strategy leading to complete recovery.

Case Presentation: A man in his 70s presented with progressive right upper limb weakness. MRI detected an extradural mass compressing the C5 and C6 nerve roots, initially mimicking a tumor. DSA revealed an ACC dAVF with venous drainage into the cervical epidural venous plexus, forming a varix compressing the nerve roots. Through staged embolization (transarterial and transvenous), the fistula was successfully obliterated, resulting in partial neurological improvement. However, residual foraminal varices continued to cause motor weakness. After a short observation period, the patient underwent direct posterior foraminotomy with variceal coagulation. Postoperatively, motor strength steadily improved and eventually normalized, with sustained recovery during follow-up.

Conclusion: This case highlights the rarity of cervical radiculopathy caused by an epidural venous varix secondary to ACC dAVF. Through endovascular embolization for shunt flow reduction, followed by surgical decompression, both the hemodynamic abnormality and mass effect were resolved.

Objective: Tentorial dural arteriovenous fistulas (dAVFs) are rare, accounting for 4%–8% of intracranial dAVFs, and are associated with a high risk of hemorrhage. We report a case of a hemorrhagic tentorial dAVF located at the posterior falcotentorial junction, which was successfully treated by sequential transarterial embolization (TAE) despite severely tortuous feeder anatomy.

Case Presentation: A 67-year-old man presented with impaired consciousness due to cerebellar and intraventricular hemorrhage with obstructive hydrocephalus. DSA revealed a tentorial dAVF at the posterior falcotentorial junction (Cognard type IV, Borden type III) with venous ectasia draining into the inferior vermian vein. The fistula was predominantly supplied by the left occipital artery (OA) and the right posterior meningeal artery (PMA), with minor contributions from the right OA and the bilateral tentorial arteries. Sequential TAE was performed: the PMA feeder was first occluded with n-butyl cyanoacrylate, followed by Onyx-18 (Medtronic, Irvine, CA, USA) injection via the left OA. Navigation through the severely tortuous OA and its suboccipital segment required multiple technical innovations, including an S-shaped microguidewire tip (CHIKAI X010; Asahi Intecc, Aichi, Japan) and the use of a compliant balloon catheter (Scepter XC; Terumo, Tokyo, Japan) as an anchor to advance the intermediate catheter (Phenom Plus; Medtronic). Complete obliteration of the fistula was achieved.

Conclusion: This case demonstrates that sequential TAE with technical innovations for vascular access can achieve curative treatment of tentorial dAVFs, even when feeder anatomy presents significant navigational challenges. The S-shaped wire technique and balloon-assisted intermediate catheter advancement may be applicable to other cases with tortuous vessel anatomy.

Objective: Medilizer (Medikit, Tokyo, Japan) is a distal anchoring exchange wire equipped with a soft, flexible self-expanding stent at the distal tip, designed to facilitate exchange maneuvers and device delivery. We report the use of the Medilizer for bailout guiding catheter exchange while preserving distal access.

Case Presentation: A 72-year-old man presented with progressive cerebral ischemia caused by acute right internal carotid artery (ICA) occlusion with contralateral chronic ICA occlusion. Percutaneous transluminal angioplasty (PTA) and Wingspan stent (Stryker Neurovascular, Fremont, CA, USA) placement in the right ICA were attempted under proximal balloon protection using a balloon-guiding catheter. After lesion crossing, the Medilizer was deployed from the proximal M2 to the proximal M1 segment. Cerebral angiography revealed severe cavernous ICA stenoses and multiple thrombi in the petrous ICA. During attempted PTA under proximal balloon protection, rupture of the balloon-guiding catheter necessitated an unexpected guiding catheter exchange. Because exchanging the entire system risked the loss of distal access, guiding catheter exchange was successfully attempted while maintaining the Medilizer in place using stepwise coaxial catheter advancement. Subsequent angioplasty and Wingspan stent placement achieved adequate revascularization without complications.

Conclusion: Medilizer may provide an effective bailout option for unexpected guiding catheter exchange after lesion crossing by preserving distal access during neuroendovascular procedures.

Objective: Anterior cranial fossa dural arteriovenous fistulas (ACF DAVFs) are high-risk lesions because of cortical venous drainage and are generally treated by surgical interruption of the draining vein or transarterial embolization (TAE). Transvenous embolization (TVE) has recently emerged as an alternative treatment in selected cases.

Case Presentation: A 67-year-old man with a residual ACF DAVF after previous bilateral ophthalmic artery Onyx (Medtronic, Irvine, CA, USA) embolization was referred for additional treatment. Repeat TAE was considered anatomically difficult because of distal ophthalmic artery occlusion after prior treatment. Craniotomy was presented as the standard treatment but was declined by the patient. Preoperative imaging demonstrated focal shunt localization and feasible venous access to the foot of the draining vein. TVE was therefore performed using selective venous catheterization and Onyx embolization. Complete angiographic obliteration was achieved without neurological deficit, hemorrhagic complication, or postoperative olfactory disturbance. Because of strong resistance during catheter retrieval, the microcatheter was intentionally retained to avoid venous injury.

Conclusion: TVE may represent a feasible alternative for selected residual ACF DAVFs after prior embolization when additional arterial access is limited and the venous anatomy is favorable. Careful patient selection and meticulous procedural planning remain essential.

Objective: The natural history of intracranial arterial stenosis caused by giant cell arteritis (GCA) and the effects of therapeutic interventions remain unclear. We report a case of rapidly progressive intracranial arterial stenosis associated with GCA and discuss its clinical course and the implications for endovascular management.

Case Presentation: A 75-year-old man developed multiple intracranial arterial stenoses and occlusions over several months, resulting in cerebral infarction. Percutaneous transluminal angioplasty was performed for severe stenosis of the cavernous segment of the right internal carotid artery, which exhibited delayed distal contrast opacification. Temporal artery biopsy confirmed the diagnosis of GCA. Although inflammatory markers improved with optimal medical treatment, the untreated intracranial arterial stenoses progressed rapidly, leading to extensive cerebral infarction. In contrast, no restenosis was observed at the site treated with angioplasty during the 6-month follow-up period.

Conclusion: Rapidly progressive intracranial involvement in GCA may lead to a devastating clinical course, with progression of arterial stenosis occurring despite apparent control of systemic inflammation. This case highlights that intracranial arterial stenosis due to GCA can progress rapidly even under immunosuppressive therapy, underscoring the importance of serial vascular imaging and suggesting that some patients may benefit from early consideration of endovascular treatment.

Objective: Cavernous dural arteriovenous fistula (dAVF) is often treated by transvenous embolization through percutaneous routes. However, it is sometimes difficult when venous drainage flows only into leptomeningeal venous reflux. Here, we present a case of cavernous dAVF draining predominantly into the superficial middle cerebral vein (SMCV), through which endovascular coil embolization was successfully performed by direct surgical exposure.

Case Presentation: A 62-year-old woman presented with left hemiparesis. Head CT revealed a right frontoparietal subcortical hematoma. Cerebral angiography showed retrograde leptomeningeal venous drainage (RLVD) caused by a right cavernous dAVF. Despite multiple percutaneous transvenous attempts, the cavernous sinus could not be accessed; therefore, a combined open surgical and endovascular approach was selected. After right frontotemporal craniotomy, the temporal cortical vein arising from a common trunk with the SMCV was preserved to reduce intra-sinus pressure and confirm fistula obliteration, with the puncture performed distal to this branch. The other drainage pathway, the SMCV, was cut down for sheath placement to secure stable access and minimize bleeding risk. A microcatheter was looped within the cavernous sinus for stability. Coil embolization was successfully completed under intraoperative digital subtraction angiography. After disappearance of shunt flow and RLVD, both the SMCV and the temporal cortical vein were coagulated and clipped.

Conclusion: A hybrid surgical and endovascular approach can be an alternative method in cases when percutaneous transvenous embolization is not feasible. We review the combined surgical and endovascular approach and discuss the key technical considerations for successful implementation, including indications for the hybrid approach, operating room setup, craniotomy, sheath placement, coil embolization strategies, and closure.

Objective: Vertebral artery (VA) compression associated with an arcuate foramen (AF) is a rare cause of ischemic stroke. We report a case of ischemic stroke caused by VA compression at the C1 level with a floating thrombus, highlighting the pathophysiology and treatment strategy.

Case Presentation: An older woman presented with vertigo and gait disturbance. MRI demonstrated acute infarcts in the bilateral posterior inferior cerebellar artery (PICA) territories. Angiographic studies revealed focal stenosis with a floating thrombus in the left VA at the C1 level (V3 segment), associated with compression by adjacent bony structures, as well as a stenotic lesion in the right VA at the V2 segment. CTA demonstrated external compression of the left VA associated with a left incomplete AF. Serial MRA demonstrated fluctuating visualization of the right vertebrobasilar system before treatment. Given that posterior circulation perfusion depended on the dominant right VA and hemodynamic compromise was suspected, revascularization of the right VA with stent placement was performed first to improve antegrade flow. This was followed by elimination of the embolic source by parent artery occlusion of the left VA in the same session.

Conclusion: VA compression associated with an AF may result in ischemic stroke primarily through artery-to-artery embolism, with possible contribution from hemodynamic compromise. Treatment strategies should be tailored based on both the embolic mechanism and the hemodynamic status of the vertebrobasilar circulation.

Objective: Mechanical thrombectomy can be challenging in cases of hard or calcified thrombi that are resistant to conventional aspiration and stent-retriever techniques. The Nimbus stent retriever (Johnson & Johnson, Warsaw, IN, USA) is designed to improve outcomes in cases with hard clots.

Case Presentation: An 80-year-old woman presented with an acute ischemic stroke due to left M2 occlusion. Preprocedural imaging revealed a markedly hyperattenuating lesion on CT and a susceptibility effect on T2*-weighted imaging at the occlusion site. During lesion crossing, marked resistance was encountered when advancing the microguidewire and microcatheter. Aspiration and conventional combined techniques failed to achieve recanalization. A Nimbus stent retriever was used as a rescue device. The stent retriever was deployed across the thrombus while aligning its proximal segment with the clot and partially re-sheathed until resistance was encountered, followed by retrieval of the stent retriever and aspiration catheter as a single unit under continuous aspiration. Successful recanalization was achieved (modified Thrombolysis in Cerebral Infarction score 2B). Histopathological examination of the resected specimen revealed a calcified thrombus. Transthoracic echocardiography and chest CT revealed mitral valve calcification.

Conclusion: Nimbus may be particularly useful for retrieving calcified or unusually firm thrombi that are resistant to conventional thrombectomy techniques.

Objective: Kasabach–Merritt syndrome (KMS) is a life-threatening disorder characterized by severe thrombocytopenia and consumptive coagulopathy associated with vascular tumors, typically Kaposiform hemangioendothelioma (KHE) or tufted angioma. Drug therapy is the first-line treatment, but some cases are refractory, and no established salvage therapy exists. This report describes a case of KMS resistant to multiple drug therapies in which transarterial embolization (TAE) was successfully performed.

Case Presentation: A 2-month-old male infant presented with a left posterior neck mass. Examination revealed severe thrombocytopenia (5000/μL) and coagulation abnormalities. Imaging studies diagnosed KMS with KHE. Platelet counts did not improve despite sequential treatment with corticosteroids, beta-blockers, and sirolimus. TAE was indicated due to the high risk of fatal bleeding. Angiography identified feeding vessels from the posterior muscular branch of the vertebral artery and the ascending cervical artery. TAE was performed using 20% n-butyl-2-cyanoacrylate (NBCA) for the vertebral artery branch and gelatin sponge particles for the ascending cervical artery branch. Post-embolization, platelet counts normalized, and the tumor shrank.

Conclusion: In a case of drug-resistant KMS, TAE effectively restored platelet counts and prevented fatal complications. When performed with appropriate embolic selection and careful complication management, arterial embolization can be a useful adjunctive treatment.

Objective: We report a rare case of delayed intracerebral hemorrhage that was possibly related to venous outflow impairment after transarterial embolization (TAE) with Onyx (Medtronic, Dublin, Ireland) for a tentorial dural arteriovenous fistula (DAVF). We also discuss the potential role of susceptibility-weighted imaging (SWI) in the early detection of postoperative venous circulatory disturbance.

Case Presentation: A 65-year-old man with a history of atherosclerotic stroke was diagnosed with a left tentorial DAVF (Borden type III, Cognard type IV). TAE with Onyx was performed, and complete obliteration of the shunt was achieved. MRI obtained 1 day after embolization revealed FLAIR hyperintensity near the shunt point and hypointense signals on SWI, suggesting venous outflow impairment. On postoperative day 6, the patient developed a large subcortical hemorrhage that required emergency decompressive craniotomy. Follow-up angiography confirmed persistent shunt occlusion. The patient was subsequently transferred to a rehabilitation facility with a modified Rankin Scale score of 4.

Conclusion: This case illustrates a rare instance of delayed hemorrhage after Onyx TAE for a tentorial DAVF, possibly related to venous outflow impairment after embolization. SWI may be a useful adjunctive imaging modality for the early detection of postoperative venous circulatory disturbance.

Objective: The occipital artery (OA) typically originates from the external carotid artery; however, rare anatomical variants exist in which it arises from the internal carotid artery (ICA). Because the OA generally has anastomoses with the deep cervical and vertebral arteries, the OA in the present case, which originated from the ICA, functioned as a collateral pathway in the setting of ICA stenosis due to this unique anatomical variant. Furthermore, it may represent a potential embolic route during carotid artery stenting (CAS). We report the hemodynamic characteristics of and treatment strategy for the present case.

Case Presentation: A 65-year-old man was found to have carotid artery stenosis during a routine brain screening and was referred to our department (Department of Neuroendovascular Therapy, Yokohama Municipal Citizen’s Hospital) for further evaluation. Cerebral angiography and CTA revealed severe stenosis of the right ICA, as well as a collateral pathway through which blood flowed retrogradely from the deep cervical artery through the OA into the distal segment of the stenotic ICA. It was considered that an OA, which originally arose from the ICA, had changed to retrograde flow as a collateral pathway following the development of ICA stenosis. Because distal protection alone was deemed insufficient for embolic prevention, CAS was performed under flow reversal with occlusion of the common carotid artery, ICA, and external carotid artery, and the procedure was completed without major complications.

Conclusion: In cases of ICA stenosis accompanied by an OA originating from the ICA, individualized embolic protection strategies based on detailed anatomical and hemodynamic evaluation are essential, with careful consideration of the risk of embolization via collateral pathways.

Objective: Endovascular embolization with Onyx (Medtronic, Minneapolis, MN, USA), a non-adhesive liquid embolic agent, is widely used to treat cerebral arteriovenous malformations (AVMs); however, ischemic complications remain a concern. Although aspiration of blood from a distal access catheter (DAC) after microcatheter retrieval is commonly performed in clinical practice, its mechanistic rationale has not been clarified. We report a case in which scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) were used to evaluate whether microscopic Onyx fragments could be detected in aspirated blood.

Case Presentation: A patient with a Spetzler–Martin grade III occipital AVM underwent transarterial embolization using Onyx. Retrieved microcatheters and blood aspirated from the DAC were analyzed using SEM/EDS. Tantalum-containing microscopic aggregates consistent with Onyx were identified on the microcatheter surface and in the aspirated blood. The detected fragments measured approximately 50–90 μm. In addition, a simplified experimental model demonstrated reproducible adhesion of Onyx to microcatheters and frequent detection of Onyx material within the DAC lumen.

Conclusion: This case demonstrates that microscopic Onyx fragments can be detected in blood aspirated from a DAC using SEM/EDS. While the clinical significance of these findings remains uncertain, our findings suggest that microscopic Onyx-derived material may persist within the catheter system after embolization.

Objective: The optimal treatment strategy for acute ischemic stroke due to intracranial atherosclerotic disease (ICAD-AIS) has not been established. The Tigertriever (Rapid Medical, Yokneam, Israel) is a unique stent retriever (SR) that allows manual adjustment of radial expansion force, a feature that may be advantageous for the treatment of ICAD-AIS. We report a case of ICAD-AIS successfully treated with SR angioplasty using the Tigertriever.

Case Presentation: A 71-year-old man developed sudden-onset left hemiplegia and was transported to our hospital 38 min after symptom onset. The National Institutes of Health Stroke Scale score was 13. MRA demonstrated occlusion of the right M1 segment of the middle cerebral artery (MCA), and diffusion-weighted imaging (DWI) showed faint hyperintensity in the posterior corona radiata. DSA revealed occlusion of the distal right M1 segment with good leptomeningeal collateral flow to the MCA territory. Given the patient’s multiple atherosclerotic risk factors, the occlusion was clinically suspected to be associated with ICAD. After administration of aspirin (200 mg) and prasugrel (20 mg), SR angioplasty was performed using a Tigertriever 17. Postprocedural DSA demonstrated residual stenosis of approximately 50%; however, no recoil or re-occlusion was observed. The puncture-to-recanalization time was 23 min. Postprocedural DWI showed only a small hyperintense lesion in the right putamen, with no evidence of re-occlusion. The patient was discharged home on day 11 with a modified Rankin Scale (mRS) of 0. The post-procedure antiplatelet regimen was aspirin (100 mg) plus prasugrel (3.75 mg) for 1 month, followed by aspirin (100 mg) plus cilostazol (200 mg) until 6 months, and aspirin (100 mg) alone thereafter. During the 9-month follow-up, the mRS remained 0 without re-occlusion of the stenotic lesion.

Conclusion: The Tigertriever may enable effective angioplasty for intracranial atherosclerotic stenotic lesions by allowing controlled adjustment of radial expansion force. This device may represent a promising therapeutic option for the treatment of ICAD-AIS.

Objective: The accessory middle cerebral artery (AMCA) is a relatively rare normal variant of the middle cerebral artery (MCA). Mechanical thrombectomy (MT) for internal carotid artery (ICA) occlusion with AMCA is very rare, and the initial diagnosis can be difficult. We illustrate a case of ICA occlusion with AMCA in which delayed diagnosis led to delayed MT.

Case Presentation: An 80-year-old man suddenly presented with only mild sensory aphasia. The National Institutes of Health Stroke Scale score was 6. Head MRI showed new punctate acute ischemic lesions. Head MRA demonstrated the left ICA occlusion and visualization of the left MCA via the anterior communicating artery. Since there were few findings that would positively suggest cardioembolic cerebral embolism, including the absence of atrial fibrillation, the patient was diagnosed with the progression of ICA stenosis to acute occlusion. Antiplatelet therapy was initiated, but 10 h later, the patient developed a progressive stroke and underwent MT, which resulted in complete recanalization, during which an AMCA was identified. The patient was transferred to a rehabilitation hospital with a modified Rankin Scale of 4.

Conclusion: A high-signal-intensity area in the main MCA on FLAIR MRI, suggesting flow stagnation, along with absent signal in the same region on time-of-flight MRA, suggesting occlusion, may be a clue to the diagnosis of ICA occlusion with a normal MCA variant.

Objective: The transfemoral approach is commonly used in neuroendovascular procedures. However, access-site complications, although infrequent, can have serious clinical consequences. Acute limb ischemia (ALI) is a particularly serious condition, carrying a significant risk of limb loss and death and therefore requires rapid diagnosis and urgent management.

Case Presentation: We report a rare case of acute external iliac artery occlusion due to a thromboembolism at the distal end of a femoral sheath after mechanical thrombectomy for acute ischemic stroke. During the procedure, reflux from both the guiding catheter and the femoral sheath disappeared, raising suspicion of an access-site complication; a contralateral femoral access angiography was performed. This evaluation revealed complete occlusion of the external iliac artery. Immediate thrombectomy was performed via a cut-down approach using a Fogarty arterial embolectomy catheter (Edwards Lifesciences, Irvine, CA, USA), resulting in the rapid restoration of arterial blood flow. The patient experienced neither limb ischemia nor neurological deterioration and achieved a favorable outcome.

Conclusion: Thrombotic occlusion at the tip of a femoral sheath is a rare but potentially devastating complication of neuroendovascular procedures. The loss of reflux from a femoral sheath should alert clinicians to the possibility of access-vessel thrombosis and prompt immediate vascular evaluation and multidisciplinary intervention.

Objective: Patients with adult congenital heart disease (ACHD) are at increased risk of thromboembolic events. However, case reports describing the use of mechanical thrombectomy (MT) for acute large-vessel occlusion (LVO) in this population remain limited. This case report describes an LVO caused by cardiogenic embolism in an adult patient who underwent the Fontan procedure for tricuspid atresia.

Case Presentation: A 31-year-old woman with a history of an extracardiac Fontan procedure for tricuspid atresia presented with right-sided paralysis and leftward conjugate deviation. CTA revealed occlusion of the left internal carotid artery with a large ischemic penumbra. MT was performed using a direct aspiration first-pass technique, resulting in complete reperfusion. The patient was discharged with mild residual impairment of dexterity in the right upper hand. At 24 years of age, she had previously developed a large vessel occlusion in the M1 segment of the middle cerebral artery, which was successfully treated with MT, leaving only mild deficits. Despite a comprehensive evaluation for an embolic source, no source was identified. She was therefore diagnosed with embolic stroke of undetermined source and was treated with direct oral anticoagulants. Cardiac CT and delayed-enhancement MRI at the current presentation revealed a thrombus in the rudimentary right ventricle that had not been detected by echocardiography. Anticoagulation therapy was initiated, and no recurrence of thromboembolic events was observed.

Conclusion: Although rare, LVO can occur at a young age in patients with ACHD. A thorough understanding of the unique anatomical characteristics of this population is essential for identifying the source of embolism and optimizing management strategies.

Objective: This study aimed to report a case of delayed rupture presenting as a direct carotid-cavernous fistula following flow diversion for a cavernous internal carotid artery aneurysm with enlarging blebs.

Case Presentation: An 82-year-old woman with a progressively enlarging right cavernous internal carotid artery aneurysm and 2 enlarging blebs underwent flow diversion using a Pipeline embolization device (Medtronic, Irvine, CA, USA) under dual antiplatelet therapy. On postoperative day 1, diffusion-weighted MRI revealed a small right corona radiata infarction causing mild disorientation and left hemiparesis; the patient remained ambulatory. On postoperative day 6, she developed pulsatile tinnitus without headache. 3D-CTA and cerebral angiography revealed rupture of a neck-adjacent bleb, with the formation of a new direct carotid-cavernous fistula (Barrow type A). Because a balloon occlusion test performed prior to flow-diverter treatment demonstrated intolerance to parent artery occlusion, parent artery sacrifice was considered infeasible. A microcatheter was advanced transvenously into the cavernous sinus and subsequently into the aneurysm sac through the rupture site and coil embolization was performed, resulting in a marked reduction in shunt flow with disappearance of cortical venous reflux. The patient was transferred to a convalescent rehabilitation hospital for rehabilitation of left hemiparesis and was discharged home 3 months after onset with a modified Rankin Scale (mRS) score of 1.

Conclusion: Even extradural cavernous internal carotid artery aneurysms may undergo delayed rupture following flow-diverter placement. In aneurysms with enlarging blebs, careful early surveillance is warranted, and transvenous intra-aneurysmal embolization may be an effective alternative when parent artery occlusion is not feasible.

Objective: Percutaneous transluminal angioplasty and stenting (PTAS) have been reported as a useful endovascular intervention for innominate artery stenosis (IAS); however, reports of treatment completed exclusively via an upper-extremity approach are limited. Here, we report 2 cases of IAS in which transfemoral access was not feasible and were successfully treated with PTAS via upper-extremity access.

Case Presentation: Case 1—A 74-year-old woman was admitted with a cerebral infarction due to left carotid artery stenosis. Severe stenosis at the origin of the innominate artery caused right hemisphere hypoperfusion. Transfemoral access was at high risk owing to an abdominal aortic aneurysm. PTAS for IAS was performed via brachial access using a sheathless balloon-guiding catheter positioned distal to the lesion. Temporary balloon occlusion resulted in distal flow arrest for cerebral protection. No new ischemic lesions were observed postoperatively. Case 2—An 80-year-old woman presented with left-sided weakness and a history of surgical angioplasty for bilateral femoral artery occlusion. Diffuse plaques in the innominate arteries caused embolic cerebral infarctions that were refractory to medical therapy. The right vertebral artery was occluded or hypoplastic. Distal protection of the right internal carotid artery was achieved using a filter device via the radial approach, followed by PTAS via the brachial approach. No postoperative cerebral infarction was observed.

Conclusion: PTAS with distal embolic protection via upper-extremity access has achieved favorable outcomes. Distal embolic protection strategies should be individualized for each IAS case.

Objective: This study aimed to report a case of falcotentorial dural arteriovenous fistula (dAVF) presenting with obstructive hydrocephalus caused by an unusual venous drainage pattern and to describe a staged treatment strategy.

Case Presentation: A 38-year-old man presented with photopsia and was found to have obstructive hydrocephalus. MRI demonstrated compression of the cerebral aqueduct by a dilated draining vein. DSA revealed a falcotentorial dAVF with deep venous reflux, supplied by multiple arterial feeders. Venous drainage occurred through a dilated trans-mesencephalic venous pathway, which compressed the cerebral aqueduct, resulting in obstructive hydrocephalus. Because hydrocephalus was present and embolization was considered to carry a risk of worsening obstruction of the cerebral aqueduct, endoscopic third ventriculostomy (ETV) was performed as the initial treatment. After improvement of hydrocephalus, staged transarterial embolization was successfully performed. At 6-month follow-up, DSA showed a small recurrent shunt without clinical deterioration, and the patient remained symptom-free.

Conclusion: Falcotentorial dAVF can cause obstructive hydrocephalus depending on venous drainage patterns. When deep venous structures compress the cerebral aqueduct, careful evaluation of venous anatomy and a staged treatment approach, including initial ETV, may be useful for safe management.

Objective: The mastoid emissary veins (MEVs) traverse the mastoid emissary canal (MEC) and connect the sigmoid sinus to the extracranial venous system. Although MEVs are frequently identified on angiography, an intraosseous arteriovenous fistula (AVF) arising primarily within the MEC has not been previously reported. Herein, we report a rare case of intraosseous AVF of the MEC that was successfully treated using a combined endovascular approach.

Case Presentation: A 70-year-old woman presented with progressive left-sided pulsatile tinnitus. DSA revealed an intraosseous AVF localized in the left MEC. The fistula was supplied by the occipital and ascending pharyngeal arteries, with retrograde drainage into the sigmoid sinus and ipsilateral transverse sinus and antegrade drainage into the extracranial subcutaneous veins, without cortical venous reflux. Because the shunt point was located in a short osseous canal adjacent to a patent sigmoid sinus, transarterial embolization (TAE) alone posed a high risk of embolic migration. Therefore, transvenous coil embolization was performed first to protect the sinus, followed by TAE using Onyx (Medtronic, Irvine, CA, USA). Complete obliteration of the fistula was achieved without compromising the sigmoid sinus.

Conclusion: The present case represents a previously unreported intraosseous AVF confined to the MEC. For fistulas located in short bony venous segments adjacent to a functional sinus, a combined transvenous embolization and TAE strategy may be a safe and effective option.

Objective: Basilar artery perforator aneurysms (BAPAs) are rare causes of subarachnoid hemorrhage (SAH), and their optimal treatment strategy remains controversial. We report a case of ruptured BAPA successfully treated in the subacute phase with an overlapping stent technique using LVIS Blue stents (Terumo Neuro, Tustin, CA, USA).

Case Presentation: A 75-year-old woman presented with SAH (Hunt and Hess grade II). Non-contrast head CT demonstrated SAH predominantly in the posterior cranial fossa. Initial DSA performed on the day of onset did not demonstrate a definite aneurysmal lesion; however, subtle focal contrast pooling was observed along the basilar artery (BA) trunk. Repeat DSA performed 4 days later revealed a small saccular dilatation arising from the BA trunk adjacent to a perforating artery. Although initial conservative management was selected, subsequent follow-up angiography demonstrated enlargement of the aneurysmal dilatation. Endovascular treatment with deployment of 2 overlapping LVIS Blue stents was performed on day 16 after onset. The postoperative course was clinically uneventful, with no rebleeding or symptomatic complications; a small asymptomatic diffusion-weighted imaging lesion was noted postoperatively. Follow-up DSA at 1 month demonstrated complete obliteration of the aneurysm.

Conclusion: The stent-overlap technique represents a feasible and effective treatment option for ruptured BAPAs. In particular, overlapping stent placement appears to be effective for basilar trunk–related subtypes, in which adequate flow diversion can be achieved while preserving perforator patency.

Objective: To describe the feasibility of Woven EndoBridge (WEB; Terumo Neuro, Aliso Viejo, CA, USA) treatment for an aneurysm at the distal anterior cerebral artery A4 bifurcation and to highlight technical considerations for achieving peripheral access.

Case Presentation: A 57-year-old woman was incidentally diagnosed with an unruptured distal anterior cerebral artery aneurysm during a brain MRI performed for evaluation of headache. DSA demonstrated a wide-neck aneurysm arising at the A4 bifurcation of a right-dominant bihemispheric distal anterior cerebral artery (neck width, 5.90 mm; dome, 6.53 × 7.76 mm [mean, 7.15 mm]; height, 6.82 mm). Given the broad neck configuration and the necessity of preserving both distal branches, intrasaccular flow disruption using a WEB device was considered appropriate. Advancement through the A1 segment was impeded by steep angulation at the internal carotid artery–A1 junction and a pronounced ledge effect. The buddy-wire technique was initially attempted to improve support and trackability, but was unsuccessful. Stable access to the A2 segment was achieved only after catheter reshaping without further use of the buddy wire. A WEB SL 8 × 3 mm device (Terumo Neuro) was deployed, achieving adequate neck coverage with a marked reduction in aneurysmal inflow while maintaining patency of both distal anterior cerebral artery branches. The procedure was completed without any procedure-related complications. Follow-up MRI/MRA at 1 month showed no evidence of residual aneurysm filling and no branch-related complications.

Conclusion: In selected distal anterior cerebral artery aneurysms where branch preservation is essential and parent-artery protrusion can be avoided, WEB treatment may be a useful endovascular option. This case illustrates the feasibility of WEB treatment of aneurysms at the anterior cerebral artery A4 bifurcation.

Objective: We report a ruptured internal carotid artery–ophthalmic artery (ICA–OphA) aneurysm in which morphological variation of the C2 segment, including marked medial deviation of the ICA, was suggested to be associated with aneurysm formation and may have influenced the endovascular strategy.

Case Presentation: A 52-year-old woman presented with subarachnoid hemorrhage. CTA revealed a right ICA–OphA aneurysm accompanied by pronounced medial deviation of the right ICA at the C2 segment. This deviation created an acutely angled ICA–OphA bifurcation, with the OphA originating from the medial aspect of the ICA. Emergency coil embolization was performed, and the aneurysm was successfully occluded.

Conclusion: The patient exhibited well-developed anterior clinoid process and optic strut morphology, which may have contributed to medial deviation of the ICA and to aneurysm formation at the ICA–OphA bifurcation. Recognition of such morphological variations is important because they may obscure OphA visualization and affect device selection. In these settings, preshaped S-type microcatheters may facilitate stable catheterization and safe coil embolization.

Objective: Flow diverter stent (FDS) deployment in neuroendovascular therapy carries a risk of vessel injury related to unintended distal advancement of the delivery wire, particularly in cases with distal aneurysms. Safe control of wire behavior during deployment remains challenging. We describe a deployment strategy using a distal access catheter (DAC) to mitigate this risk.

Case Presentation: We report a case of a 79-year-old man with multiple intracranial aneurysms, including a symptomatic large aneurysm of the right internal carotid artery and an additional distal aneurysm at the middle cerebral artery bifurcation. A Surpass Evolve Flow Diverter (Stryker, Kalamazoo, MI, USA) was deployed in the right internal carotid artery. The device was initially deployed using the standard technique; however, the deployment strategy was subsequently changed to release the device within the DAC, followed by gradual unsheathing of the catheter, to mitigate the risk of distal advancement of the delivery wire. The FDS was successfully deployed without distal wire migration or vessel injury. The postoperative course was uneventful, with no procedure-related complications.

Conclusion: This case highlights a practical rescue strategy for situations in which distal wire control during FDS deployment is particularly important. Deploying an FDS within a DAC and releasing it by unsheathing may help mitigate the risk of uncontrolled distal wire advancement and enhance procedural safety in carefully selected complex cases with distal aneurysms.

Objective: We report a case of seizure-associated transient early venous visualization (EVV) on cerebral angiography in a patient with glioblastoma mimicking arteriovenous shunting pathology.

Case Presentation: A 48-year-old woman presented with new-onset generalized tonic–clonic seizures. Brain MRI revealed a poorly demarcated, non-enhancing lesion in the left temporal lobe. Arterial spin labeling (ASL) demonstrated marked hyperperfusion within the lesion and adjacent venous sinuses. Cerebral angiography performed approximately 2 h following seizure cessation showed posterior temporal artery dilation and an EVV pattern, with shunting into the vein of Labbé and the ipsilateral transverse and sigmoid sinuses; this raises suspicion for an arteriovenous shunting lesion. No definitive arteriovenous fistulae or thromboses were identified. The patient was managed with antiepileptic therapy alone, which led to clinical improvement. Follow-up MRI and angiography 2 weeks later revealed complete resolution of ASL hyperperfusion and the EVV pattern. Subsequent histopathological examination of the resected tumor confirmed isocitrate dehydrogenase (IDH)-wild-type small cell glioblastoma. Despite the underlying malignant tumor and persistent seizure susceptibility, the angiographic abnormalities and altered venous drainage were entirely reversible and seizure-induced, rather than structurally pathological.

Conclusion: This case illustrates that ictal or postictal cerebral hyperperfusion can produce transient EVV on cerebral angiography, even with aggressive neoplasms such as glioblastoma. Recognizing this phenomenon is essential to avoid misdiagnosing a true arteriovenous shunting lesion, thereby preventing unnecessary intervention procedures and guiding appropriate management. When interpreting angiographic abnormalities observed shortly after seizures, integration of perfusion-based MRI findings with the temporal evolution of symptoms is crucial.

Objective: This work highlights the importance of recognizing persistent left superior vena cava (PLSVC), which is an uncommon venous anomaly that may complicate venous access during neuroendovascular procedures. Although rarely encountered in routine neurosurgical practice, identification of this anomaly can guide appropriate access selection and facilitate safe procedural planning.

Case Presentation: An 81-year-old woman presented with tinnitus. Magnetic resonance imaging revealed a left sigmoid sinus dural arteriovenous fistula (dAVF). Cerebral angiography revealed feeders mainly from the left occipital artery and shunt points at both the distal sigmoid sinus and jugular valve. The proximal transverse sinus was occluded, and venous drainage proceeded anterogradely into the internal jugular vein (IJV). The lesion was classified as Borden type I, and transvenous embolization was selected as the treatment strategy. The left brachiocephalic vein could not be catheterized during the procedure. Angiography revealed a PLSVC without the left brachiocephalic vein, and cone-beam CT confirmed drainage into the right atrium via the coronary sinus. A guide system was successfully navigated into the left IJV through the PLSVC, and coil embolization was performed from the distal to proximal segments. Final angiography confirmed complete obliteration of the shunts, and the tinnitus resolved.

Conclusion: Awareness of PLSVC, even for neuroendovascular surgeons with limited exposure to the thoracic venous anatomy, can aid in selecting optimal venous access routes and help avoid unexpected procedural difficulties. This case demonstrates that recognizing a PLSVC can meaningfully contribute to the success of transvenous embolization.