Over the past decade, clinicians and researchers have increasingly recognized the significance of the glymphatic system. Evidence demonstrates that this system—named for its reliance on astrocyte endfeet of glial cells and its lymphatic-like waste clearance function from the brain—is essential for regulating the accumulation and removal of amyloid aggregates and other interstitial waste products that may cause cognitive decline if not removed. Its activity is highly regulated, with flow driven by arterial wall pulsatility linked to the cardiac cycle, facilitating perivascular cerebrospinal fluid (CSF) influx into the brain interstitium and its efflux into the venous system. In the present review, we highlight the interplay between the glymphatic system and neurovascular diseases, as well as conditions that are currently being treated by endovascular means, including subarachnoid hemorrhage, idiopathic intracranial hypertension, steno-occlusive disease, and arteriovenous shunting diseases. We describe how changes in arterial pulsatility, disturbances in para-arterial CSF influx, changes in aquaporin-4 receptor composition, or venous hypertension with a decreased arteriovenous pressure gradient can cause dysfunction of different components of the glymphatic system, leading to similar clinical symptomatology with progressive cognitive decline that may be reversible.

Objective: Flow diverter (FD) stents are a promising treatment option for complex intracranial aneurysms. However, rapid hemodynamic changes, thrombus formation, and complex morphologies can increase rupture risk and pose technical challenges. To address these concerns, a “staged treatment” with initial coil embolization followed by delayed FD placement has been introduced. This study aimed to evaluate its clinical outcomes, safety, and technical feasibility, including in anatomically challenging aneurysms.

Methods: A retrospective analysis was conducted on 11 patients with intracranial aneurysms who underwent initial coil embolization followed by FD placement at our institution between 2018 and 2024. The data collected included aneurysm characteristics, number of coils used, initial volume embolization ratio (VER), interval between coil embolization and FD placement, and procedure-related complications.

Results: Of the 11 patients, 10 were female. Nine aneurysms were large (>10 mm) and 2 were giant (>25 mm). The median initial VER was 18% and the median interval between coil embolization and FD placement was 79 days. All the FD procedures were technically successful, even in aneurysms for which direct distal navigation was expected to be difficult. No permanent complications or delayed ruptures occurred during the follow-up. At the 12-month follow-up DSA, 81.8% of the patients achieved complete occlusion (O’Kelly-Marotta [OKM] grade D), and all cases were graded as OKM C or higher. All patients had favorable clinical outcomes, with modified Rankin Scale scores of 0 or 1.

Conclusion: Staged FD treatment appears to be a safe and effective therapeutic option for treating large, ruptured, or morphologically complex intracranial aneurysms. This approach may serve as a valuable alternative in cases in which primary FD deployment poses a high procedural risk. Moreover, the use of coils in the initial stage may offer a mechanical scaffold that facilitates a more stable and safer FD delivery. Nevertheless, further studies are warranted to determine the optimal coil packing density and timing of the FD placement.

Objective: Mechanical thrombectomy alters cerebrovascular hemodynamics in ways that remain poorly characterized. This in vitro study investigated the pressure restoration rate (PRR), a quantitative measure of how quickly pressure returns to baseline in an occluded vessel, during thrombectomy using aspiration and stent-retriever devices in different cerebrovascular anatomical configurations.

Methods: A cerebrovascular glass model with pulsatile flow was constructed to simulate good (symmetrically connected) and poor (unilateral) collateral anatomy. Pressure sensors were integrated into the system to record hemodynamic responses during thrombectomy procedures using SOFIA 5F and 6F aspiration catheters (Terumo Neuro, Aliso Viejo, CA, USA) and a Solitaire 6 × 30-mm stent retriever (Medtronic, Irvine, CA, USA). PRR was calculated in the middle cerebral artery at a 5-ms resolution and compared across devices and anatomical variants using Kruskal–Wallis tests.

Results: Aspiration thrombectomy exhibited significantly higher PRRs than the stent-retriever thrombectomy across both good and poor collateral models (p <0.05). Median PRRs were 17.9 μmmHg/5 ms (SOFIA 5F), 13.5–14.3 μmmHg/5 ms (SOFIA 6F), and 0.8–1.3 μmmHg/5 ms (stent retriever). Aspiration was associated with a rapid, near-instantaneous return to baseline pressure, whereas stent-retriever thrombectomy produced a more gradual restoration with a plateau phase followed by a lower magnitude instantaneous return. Momentary reciprocal pressure fluctuations were also observed in neighboring vessels during clot removal.

Conclusion: This study demonstrates that thrombectomy induces different hemodynamic flow return patterns in the targeted vessel, with technique-specific PRR values. High PRRs, particularly with aspiration, may subject compromised cerebral vessels to potentially injurious pressure surges during reperfusion. These findings suggest a possible mechanistic link between device-technique modality and complications such as hemorrhagic transformation, warranting further investigation in clinical settings.

Objective: Mechanical thrombectomy (MT) is the standard of care for acute ischemic stroke, and its outcomes are highly dependent on operator experience. While integrating junior physicians into MT practice is crucial for sustainable workforce development, it poses a challenge in maintaining procedural quality during their training. Although the Japanese Society for Neuroendovascular Therapy (JSNET) provides a board certification system in Japan, the impact of an operator’s certification status on MT outcomes remains uncertain. Therefore, this study aimed to validate the safety and efficacy of MT performed by noncertified operators under specialist supervision by comparing their outcomes with those achieved by board-certified specialists.

Methods: We conducted a single-center retrospective study of patients undergoing MT between January 2020 and December 2024. Patients were stratified into 2 groups based on the primary operator's certification status. Primary outcomes were assessed across 3 domains: efficacy (successful reperfusion, defined as a modified Thrombolysis in Cerebral Infarction score ≥2b, and favorable functional outcome, defined as a 90-day modified Rankin Scale score of 0–2), safety (symptomatic intracranial hemorrhage [sICH]), and efficiency (puncture-to-reperfusion time). Secondary efficacy measures included the modified 1st-pass effect (mFPE) and the number of passes. Multivariable logistic regression analysis was performed to evaluate whether operator certification status was independently associated with clinical outcomes. In all procedures performed by noncertified operators, a JSNET board-certified specialist was scrubbed in and provided direct supervision.

Results: Eighty-seven patients met the inclusion criteria. Forty-three were treated by board-certified specialists and 44 by noncertified operators under direct supervision. The groups did not differ significantly in efficacy outcomes, including successful reperfusion (97.7% in board-certified vs. 93.2% in noncertified; p = 0.62), favorable functional outcome (51.2% vs. 43.2%; p = 0.46), and the achievement of mFPE (65.1% vs. 52.3%; p = 0.22). The primary safety outcome of sICH was also comparable (7.0% vs. 9.1%; p = 1.00). However, the efficiency outcome, puncture-to-reperfusion time, was significantly shorter in the board-certified group (median, 29 vs. 38 minutes; p = 0.02). In the multivariable analysis, only younger age and mFPE achievement were independently associated with favorable outcome, whereas the operator’s certification status was not (p = 0.75).

Conclusion: Under direct supervision, MT performed by noncertified operators demonstrated comparable efficacy and safety to procedures performed by board-certified specialists, albeit with lower efficiency. These data endorse structured, supervised training pathways that protect patient outcomes while developing the next generation of neurointerventionalists.

Objective: In recent years, mechanical thrombectomy and aspiration catheter technology have advanced significantly, with newer aspiration catheters (ACs) featuring larger lumens and improved outcomes. However, the specific features driving these improvements remain unclear. The aim of this study was to compare treatment outcomes between the latest-generation large-bore ACs (LACs) and conventional aspiration catheters (CACs) in patients undergoing mechanical thrombectomy.

Methods: In this retrospective single-center cohort study conducted at the authors’ institution, we analyzed data from patients who underwent mechanical thrombectomy using ACs for internal carotid artery (ICA) or M1 segment middle cerebral artery (M1) occlusions between November 2017 and October 2022. Cases were classified into LAC (inner diameter ≥0.0710 inches) and CAC groups. Patient demographics and procedural features were evaluated, including 1st-pass effect (FPE), catheter-to-vessel match (CVM), and clot contact rates. Group comparisons were performed using the Mann–Whitney U-test or the chi-squared test. Univariate and multivariate logistic regression analyses were conducted for M1 occlusion cases treated with LACs.

Results: The study cohort comprised 159 patients who underwent mechanical thrombectomy using ACs. The FPE success rate was significantly higher in the LAC group (52.8%) than in the CAC group (34.0%). With regard to the occlusion site, this rate was not significantly different between the LAC and CAC groups for ICA occlusions; however, for M1 occlusions, the LAC group demonstrated a significantly higher FPE rate than the CAC group (P = 0.009). CVM and clot contact rates were significantly higher in the LAC group (P = 0.001 and P ≤0.0001, respectively). In the LAC group, both CVM and clot contact were independently associated with FPE success in cases of M1 occlusion (odds ratio, 10.9; 95% confidence interval, 3.3–36.7; P <0.0001; odds ratio, 18.0; 95% confidence interval, 1.9–172.9; P = 0.013, respectively).

Conclusion: LACs yielded significantly better outcomes for M1 occlusions than CACs. The enhanced FPE rate appears attributable to 2 design advantages: increased bore size, which improves CVM, and superior trackability, which enhances clot contact. These findings suggest that, given the vessel diameter variations caused by factors beyond anatomical location, tailoring mechanical thrombectomy methods and device selection to individual vascular anatomy, rather than relying on fixed vessel-based criteria, may improve treatment outcomes.

Objective: Endovascular treatment of wide-neck cerebral aneurysms with conventional coiling alone remains challenging. Stent-assisted coiling using a vascular reconstruction device offers an alternative strategy. This study evaluated the safety and effectiveness of the Enterprise Vascular Reconstruction Device (Cerenovus, Irvine, CA, USA) in patients with wide-neck cerebral aneurysms.

Methods: Post-marketing surveillance records were collected for all Enterprise stent usage using case report forms at 30 days and at 1, 2, and 3 years post-procedure. A total of 738 cases, including 411 on-label cases, were analyzed across 83 hospitals.

Results: Stent deployment was successful in 98.8% of cases, and the overall procedure success rate was 93.9% immediately post-procedure. The aneurysm occlusion rate was 92.90%, with 73.7% classified as Raymond–Roy class I/II immediately post-procedure. Among the 411 on-label cases, 17 patients (4.1%) demonstrated worsening of the modified Rankin Scale score, but no deaths were attributable to the utilization of the Enterprise device. The postoperative ischemic stroke complication rate was low (4.5%) but increased significantly in patients with a proximal parent artery diameter <2.5 mm (18.6%) and in those aged ≥65 years (8%). Multivariable logistic regression revealed that age ≥65 years, diabetes, hypertension, and a past medical history of ischemic stroke were significant risk factors for postoperative ischemic stroke.

Conclusion: Vascular reconstruction device implantation was effective and safe for treating wide-neck cerebral aneurysms.

Objective: The technique combining a stent retriever (SR) and contact aspiration (CA) has been widely used in mechanical thrombectomy for acute ischemic stroke. However, advancements in large-bore aspiration catheters suggest that CA alone may achieve comparable therapeutic outcomes, while streamlining the procedure. Nevertheless, real-world evidence directly comparing these approaches is limited.

Methods: We identified patients hospitalized for ischemic stroke who underwent mechanical thrombectomy between April 2020 and March 2023 from the Japanese national inpatient Diagnosis Procedure Combination database. Patients treated with CA or CA combined with SR (CA + SR) were enrolled. Propensity score overlap weighting was performed to adjust for confounders. The outcomes were intracranial hemorrhage (ICH), functional independence at discharge, in-hospital mortality, and total hospitalization cost.

Results: Among 17589 eligible patients, 14892 underwent CA + SR and 2697 received CA. The adjusted proportions of ICH were comparable between the groups (1.4% vs. 1.3%; adjusted risk difference [aRD], 0.1%; 95% confidence interval [CI], −0.5% to 0.5%). The CA + SR group had a lower proportion of functional independence at discharge (28.7% vs. 36.2%; aRD, −7.5%; 95% CI, −9.5% to −5.4%) and higher in-hospital mortality (11.4% vs. 9.2%; aRD, 2.2%; 95% CI, 1.0%–3.5%). The total hospitalization costs (USD) were higher in the CA + SR group than in the CA group (21687 vs. 18317; difference, 3370; 95% CI, 2976–3764).

Conclusions: The proportion of patients with ICH did not differ significantly between the CA + SR group and CA groups. CA + SR was associated with worse functional outcomes, higher in-hospital mortality, and higher costs.

Objective: Carotid artery stenting (CAS) has been reported to be a safe and effective option for treating carotid atherosclerotic disease. However, reports and studies from resource-limited countries are scarce. The published data support the use of embolic protection devices (EPDs) to reduce periprocedural stroke. This study aimed to evaluate the outcomes of CAS procedures without EPDs in Yemen, one of the lowest-income countries.

Methods: This is a retrospective cohort study regarding CAS for symptomatic carotid artery stenosis that was conducted at the stroke center of Borg Al-Atiba and American Modern Hospital during the period from March 2023 to March 2025. All patients with symptomatic carotid artery stenosis were included in the study. CAS procedures were performed by a single interventional neurologist. The primary outcomes included a 30-day periprocedural mortality, stroke, myocardial infarction, or arrhythmia. Any other complications were considered secondary outcomes.

Results: A total of 62 patients (53 males) were included in this study, with a mean age of 60.2 ± 9.7 years. All patients had symptomatic carotid artery stenosis. The technical success rate was 100%. No perioperative cerebral infarctions were observed. One patient developed transient dysarthria, but diffusion-weighted-MRI was negative. Significant bradycardia occurred in 2 patients and responded immediately to atropine. Three patients developed mild local hematoma, and 1 patient had a femoral pseudoaneurysm. Closed-cell Carotid WALLSTENT (Boston Scientific, Marlborough, MA, USA) was used as a single stent in all patients.

Conclusion: CAS conducted by a trained interventional neurologist without EPDs demonstrates a low complication rate, and it is an effective and safe option in countries with limited resources.

Objective: Futile recanalization (FR)—a poor functional outcome despite successful reperfusion after mechanical thrombectomy (MT)—remains a significant issue in acute ischemic stroke owing to large vessel occlusion. This study aimed to identify predictors of FR, focusing on CT perfusion (CTP) parameters using our institutional retrospective data.

Methods: Patients who underwent MT at our institution between April 2015 and February 2023 were retrospectively reviewed. FR was defined as a 90-day modified Rankin Scale (mRS) score of 3–6 despite successful reperfusion (modified thrombolysis in cerebral infarction ≥2b). Patients with internal carotid artery (ICA) or M1 segment of the middle cerebral artery occlusion, pre-stroke mRS 0–2, stroke etiology classified as cardioembolic or embolic stroke of undetermined source, and available CTP were included. The ischemic core was defined as cerebral blood volume (CBV) <1.0 mL/100 g on CTP, and the Alberta Stroke Program Early CT Score (ASPECTS) was also evaluated. Clinical, imaging, and procedural variables were compared between the FR group and those with a favorable outcome (mRS 0–2) after successful reperfusion. Multivariable logistic regression was performed, including imaging markers and variables with p <0.1 in univariate analyses as covariates. Receiver-operating characteristic (ROC) analyses determined thresholds for ASPECTS and CBV-defined core volume, followed by sensitivity analyses.

Results: A total of 531 patients underwent MT during the study period, of whom 136 met the inclusion criteria (mean age 78 ± 11 years, 70 women, 46 ICA occlusions, median ASPECTS 9; interquartile range, 7–10). FR was observed in 69 patients (50.8%). Compared with the favorable outcome group, the FR group had significantly older age, higher baseline NIHSS scores, higher prevalence of diabetes mellitus, lower ASPECTS, larger CBV-defined core volumes, and a greater total number of device passes. Multivariable logistic regression identified older age, higher NIHSS, diabetes mellitus, and a greater total number of device passes as consistently independent predictors of FR. ROC analysis identified CBV-defined core volume ≥28.5 mL as an independent predictor of FR (area under the curve [AUC] 0.62, p = 0.013; adjusted odds ratio [aOR] 3.09, 95% confidence interval [CI] 1.23–8.28; p = 0.02); this association remained significant at ≥30 mL (aOR 2.82, 95% CI 1.14–7.33; p = 0.02) but not at ≥40 mL. ASPECTS ≤8 was also associated with FR (AUC 0.64, p = 0.002; aOR 2.92, 95% CI 1.20–7.44; p = 0.02).

Conclusion: Older age, baseline stroke severity, diabetes mellitus, and multiple device passes were major predictors of FR. Among imaging markers, a CBV-defined core volume of approximately 30 mL emerged as a clinically relevant threshold associated with increased FR risk. These findings suggest that integrating clinical, procedural, and imaging factors may help optimize patient selection, although validation in larger, multicenter studies is warranted.

Objective: Embolization of thrombus to a new vascular territory (ENT) is a feared and important complication of cerebral thrombectomy in acute ischemic stroke. This study explores the utilization of 2 simultaneous stent retrievers to prevent ENT, as well as its alternative setups.

Methods: An in vitro glass model with a unilateral anterior cerebral vasculature was used to recreate a challenging scenario that intrinsically facilitates ENT. Four different thrombectomy techniques were tested and compared across a total of 50 in vitro procedures: Technique [1]—single stent retriever; Techniques [2] and [3]—dual stent retrievers with asymmetric and symmetric stent retrieval, respectively; and Technique [4]—dual stent retrievers combined with distal aspiration. The success rate and time to perform the procedures were compared using the Fisher’s exact test and Mann–Whitney U test, respectively.

Results: The collective performance of dual-stent techniques [2 + 3 + 4] yielded successful recanalization on 1st pass without ENT in 24/30 cases (80%), which was statistically significantly better than the 8/20 (40%) achieved with the single-stent technique [1] (p = 0.006). The dual stent retrievers combined with an aspiration catheter [4] performed best, yielding successful recanalization on 1st pass without ENT in 10/10 cases (100%), which was also statistically significantly better compared to the single-stent technique [1] (p = 0.002). All other possible comparisons across the different techniques did not yield any statistically significant differences.

Conclusion: Overall, the results suggest that applying dual stent retrievers performs better than the single-stent-retrieval technique in preventing ENT and achieving a single-pass procedure. Among all techniques, combining dual stent retrievers with aspiration through a distal catheter performed best.

Objective: The distal transradial approach has been one of the options for endovascular neurointervention because of the low risk of puncture site complications. However, the conventional and distal transradial artery approaches frequently cause cannulation-induced vasospasms, which can usually be prevented by vasodilators. The aim was to evaluate the effects of local infiltration using a puncture site cocktail of lidocaine mixed with nitroglycerin on puncture success and vasospasm for distal transradial cerebral angiography.

Methods: A total of 85 consecutive patients who underwent cerebral angiography via distal radial artery puncture between February 2024 and December 2024 were included. Of these patients, 28 patients were excluded due to irregularities. The remaining 57 patients were eligible for this retrospective study and were divided into 2 groups: (1) underwent local anesthesia with 1% lidocaine (n = 23, Lidocaine group); and (2) puncture site cocktail of 1% lidocaine mixed with nitroglycerin (n = 34, Cocktail group). In both groups, patients’ characteristics and procedure results were retrospectively assessed. In addition, in all patients, the correlation between the number of punctures and distal radial artery diameter, and the cutoff values of distal radial artery diameters after local anesthesia for 1st puncture success were also assessed.

Results: Patient background characteristics showed no significant differences between the groups. In the procedure results, the mean diameter of the distal radial artery before local anesthesia was significantly smaller in the Cocktail group (2.1 vs 1.7 mm, p <0.05). The mean dilatation rate of the distal radial artery was significantly greater in the Cocktail group than in the Lidocaine group (1.3 vs 1.1, p <0.05); thus, there was no difference in the mean diameter after local anesthesia. The 1st puncture success rate and the mean number of punctures were not significantly different between the 2 groups. The rate of cannulation-induced distal flow arrest was significantly lower in the Cocktail group (47.8% vs 20.6%, p <0.05). Puncture site complications and radial artery occlusions were not observed in either group. There was a negative correlation between distal radial artery diameter after local anesthesia and the number of punctures (r = −0.53, 95% CI: −0.69 to −0.31, p <0.001). The cutoff value for the diameter of the distal radial artery was 1.9 mm.

Conclusion: The puncture site cocktail significantly increases the diameter of the distal radial artery, which may be related to the reduction of cannulation-induced vasospasm without periprocedural complications in cases with a small-diameter distal radial artery.

Objective: Shortening prehospital time and door-to-puncture (DTP) time are important to achieve better outcomes in patients with acute stroke. To reduce treatment delays, particularly DTP time and prehospital delays, our core hospital in the Saitama Stroke Network (SSN) implemented a series of interventions aimed at enhancing collaboration with emergency medical services (EMS) personnel and optimizing in-hospital workflows.

Methods: A revised prehospital flowchart was co-developed with the EMS to shorten on-scene time and streamline information transmission using the Cincinnati Prehospital Stroke Scale and essential clinical indicators. Simultaneously, the in-hospital stroke treatment algorithm was modified: CT was omitted, MRI was prioritized, and patients were transferred directly from the imaging suite to the operating room. Intravenous recombinant tissue-type plasminogen activator (rt-PA) was administered in the operating room. Simulation training for hospital staff was conducted bimonthly to reinforce the new protocol. We retrospectively analyzed changes in time metrics and patient volumes before (Group A, January 3, 2019, to January 3, 2020) and after (Group B, January 4, 2020, to January 4, 2021) these interventions.

Results: Among 66 patients undergoing mechanical thrombectomy (MT), DTP time significantly decreased in Group B (p <0.001), with notable improvements in door-to-imaging and imaging-to-operating room intervals. However, prehospital times showed no significant change. The number of MT procedures increased by 54%, and SSN transports rose by 43% from Groups A to B. The rates of successful recanalization (thrombolysis in cerebral infarction score ≥2b) and rt-PA administration increased, but without significant differences.

Conclusion: Although we could not shorten prehospital time sufficiently, DTP time was significantly shortened by our new algorithm and simulation training, and the numbers of acute stroke patients and MT were increased significantly through collaboration with the EMS. Further collaboration with the EMS remains an important challenge going forward.

Objective: Recent studies of endovascular thrombectomy (EVT) for anterior circulation stroke have revealed that contact aspiration (CA) and stent retriever (SR) achieve equivalent rates of effective reperfusion, neurological outcomes, and incidence of complications. However, comparative studies on the safety and efficacy of these techniques, particularly in the setting of basilar artery occlusion (BAO), are still lacking. This study aimed to compare the efficacy and safety of CA and SR thrombectomy for BAO using multicenter registry data, and to identify factors associated with better functional outcomes.

Methods: This retrospective analysis was conducted using data from the K-NET registry. Of the 3954 patients enrolled in this registry, 179 underwent EVT for BAO. Among these, 71 patients were excluded because they were treated with both an aspiration catheter and an SR. As a result, 108 patients were included in the final analysis. Patients were divided into the following 2 groups based on the treatment device used: CA (n = 71) and SR (n = 37). Baseline characteristics, procedural details, and clinical outcomes were compared between the groups. Multivariate analysis was performed to identify independent predictors of good clinical outcomes, defined as a modified Rankin Scale (mRS) score of 0–2 or no worsening of pre-stroke mRS at 90 days.

Results: The CA group required significantly fewer passes and achieved faster recanalization compared with the SR group. Furthermore, complete recanalization (modified treatment in cerebral infarction score of 3) was more frequent in the CA group (80.3% vs 59.5%, p = 0.02). Multivariate analysis revealed that CA was independently associated with good clinical outcomes (odds ratio 4.71, 95% confidence interval 1.69–13.11, p <0.01). No significant difference was observed in hemorrhagic complications between the groups.

Conclusion: Patients who underwent CA showed procedural advantages over SR thrombectomy, including more rapid recanalization with fewer passes and a higher rate of complete recanalization. These factors were found to be associated with better functional outcomes at 90 days. Further randomized controlled trials are required to confirm these findings and establish the optimal treatment strategy for BAO.

Objective: Left ventricular systolic dysfunction has traditionally been considered an unfavorable prognostic factor in stroke. However, chronic hypoperfusion due to this dysfunction may improve cerebral collateral flow, potentially serving as a compensatory mechanism during ischemic stroke. This study aimed to investigate the effects of left ventricular systolic dysfunction on outcomes after mechanical thrombectomy (MT), with a focus on cerebral collateral flow.

Methods: This retrospective cohort study included 94 consecutive patients with acute ischemic stroke who underwent MT between April 2017 and July 2022. Patients were divided into 2 groups based on their left ventricular ejection fraction (EF): the reduced EF group (EF ≤40%) and the preserved EF group (EF >40%). We evaluated post-treatment stroke volume, clinical outcomes, length of hospital stay, and the relationship between EF and cerebral collateral flow.

Results: The reduced and preserved EF groups consisted of 11 (12%) and 83 (88%) patients, respectively. No significant differences were observed in post-treatment stroke volume (13 vs. 12 cm³, p = 0.779), hospital stay duration (23 vs. 22 days, p = 0.634), or favorable clinical outcomes at discharge (36% vs. 43%, p = 0.754) between the 2 groups. The odds ratio for favorable outcomes at discharge, adjusted using inverse probability of treatment weighting, was 0.693 (95% confidence interval: 0.176–2.732, p = 0.600) for the reduced EF group compared with the preserved EF group. Cerebral collateral flow developed better in the reduced EF group (56% vs. 13%, p = 0.008).

Conclusion: Left ventricular systolic dysfunction did not significantly worsen outcomes after MT. Chronic cerebral hypoperfusion due to left ventricular systolic dysfunction may promote the development of cerebral collaterals, potentially enhancing resistance to ischemic events.

Objective: Basilar artery perforating aneurysms (BAPAs) represent an infrequent clinical finding, typically manifesting as subarachnoid hemorrhage (SAH). Consensus on the optimal management of this rare entity is lacking. We report a single-center case series of 11 patients diagnosed with BAPAs, providing a detailed description of their clinical presentation, management course, and follow-up.

Methods: A retrospective review of our institutional aneurysm database was performed, encompassing cases treated between January 2008 and 2024. Inclusion criteria required aneurysm localization to the middle or upper 3rd of the basilar artery.

Results: All cases presented with diffuse SAH, with 80% exhibiting a perimesencephalic cisternal bleeding pattern. Notably, in most cases, aneurysms were detected upon repeat angiography, performed approximately 10 days after the initial angiographic study. A conservative management strategy was employed, resulting in spontaneous aneurysm exclusion in 80% of the cohort. No instances of rebleeding were observed during the follow-up period.

Conclusion: Conservative management demonstrated favorable functional outcomes in our case series, marked by a high rate of spontaneous thrombosis. These findings suggest that conservative management is an effective and potentially preferred treatment strategy for this rare pathology, mitigating perioperative risks associated with surgical or endovascular interventions.

Objective: Compared with stent-assisted coiling (SAC), the Woven EndoBridge (WEB; Terumo Neuro, Aliso Viejo, CA, USA) device has been reported to reduce procedural duration, suggesting the potential to reduce radiation exposure for both patients and operators. However, whether WEB treatment results in lower radiation exposure than SAC has not been fully investigated. This study therefore aimed to evaluate radiation exposure associated with WEB treatment versus SAC in the management of unruptured wide-neck bifurcation aneurysms (WNBAs).

Methods: We retrospectively analyzed 46 patients treated for 47 unruptured intracranial aneurysms located at the basilar artery apex, middle cerebral artery bifurcation, or anterior communicating artery at our institution between February 2023 and April 2024. Patients were categorized into 2 groups based on the treatment modality: SAC or WEB device. Radiation exposure, fluoroscopy time, procedure duration, and number of imaging procedures were compared between groups.

Results: Baseline characteristics, including age, sex, and aneurysm location, did not differ significantly between groups. However, aneurysms were significantly larger in the WEB group, with both greater median aneurysm volume (61.9 vs. 43.2 mm³, P <0.001) and maximum dome diameter (8.2 vs. 5.4 mm, P <0.001). Radiation exposure was significantly lower in the WEB group, as indicated by lower median values for both air kerma (1888 vs. 3496 mGy, P <0.001) and dose–area product (126.3 vs. 158.9 Gy·cm², P = 0.002). The WEB group also showed significantly shorter values for both fluoroscopy time (49.1 vs. 102.3 min, P = 0.003) and procedure duration (97 vs. 146 min, P = 0.01). The number of imaging procedures and contrast medium volume did not differ significantly between groups.

Conclusion: In the endovascular treatment of unruptured WNBAs, the WEB device significantly reduces radiation exposure compared with SAC, primarily by decreasing fluoroscopy time. Given this potential to minimize radiation exposure, the WEB device may be preferable when both methods are clinically viable.

Objective: 3D DSA performed under carotid artery occlusion tests (Matas and Alcock test) while the operator manually compresses the patient’s carotid artery may be performed as a preoperative evaluation. However, few known studies have quantified the operator’s radiation exposure dose during 3D DSA under carotid artery occlusion tests. In this study, we measured the changes in the operator’s radiation exposure dose during such imaging under different protective measures and assessed alternative protective measures for hand exposure apart from protective gloves and the operator’s head and neck orientation, proposing a new protection method.

Methods: We measured changes in the operator’s radiation exposure dose under different protective measures. Specifically, we measured changes in lens dose on the operator’s head and neck orientation and the use of protective equipment. Furthermore, we evaluated alternative protective measures for hand exposure aside from protective gloves.

Results: In all measurement points, the lower measured dose was recorded when protective measures were implemented. The measured doses to the left and right lenses varied depending on the usage of protective equipment and the orientation of the operator’s head and neck. The lowest measured dose to both lenses was recorded when the protective equipment and ceiling-suspended shield were used, and the operator’s head and neck were turned toward the subject. The hand dose was the lowest when protective gloves were used (316.9 μGy), representing a 72% reduction compared with unprotected conditions. When the neck guard or lead plate was inserted underneath the measurement points, the hand dose decreased by approximately 29% (884.3 μGy) and 43% (657.6 μGy), respectively, compared with unprotected conditions.

Conclusion: Our findings confirmed that operator radiation exposure dose can be reduced through protective measures. The lens exposure dose was minimized when protective equipment and the ceiling-suspended shield were used, and the operator’s head and neck were turned toward the subject. While the protective effect of the lead plates was lower than that of protective gloves—which can be challenging to use during manual compression—the method of inserting a lead plate beneath the patient table and bending it along the shoulder was identified as another useful alternative.

Objective: Carotid endarterectomy (CEA) is a standard treatment for atherosclerotic carotid stenosis. Perioperative symptomatic restenosis or reocclusion of the carotid artery following CEA is a rare but serious complication that typically necessitates intervention. The efficacy and safety profile of emergent endovascular therapy (EVT) as an alternative to repeat CEA in the treatment of acute perioperative neurological decline remain unknown.

Methods: All patients undergoing CEA in the Department of Neurosurgery at a single comprehensive stroke center from 2015 to 2024 were reviewed. Patients who underwent EVT for acute perioperative neurological deficits were included in our series. A systematic literature review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to identify articles relevant to the endovascular management of acute neurological deficits following CEA.

Results: Four patients from our institutional cohort met the inclusion criteria. An additional 39 patients were identified from the literature review in 11 source articles, which yielded a total of 43 patients. CEA was performed for symptomatic lesions in 28 (28/32, 87.5%) patients. Abnormal angiographic findings were reported for all patients. Thrombus accumulation in or distal to the operated internal carotid artery (ICA) (26/43, 60.5%) and dissection flaps (15/43, 34.9%) were the most common findings. Five (11.6%) patients had tandem cervical ICA and intracranial occlusions, of which thrombectomy of the intracranial lesion was successfully performed on 3 patients. All patients except for 1 (42/43, 97.6%) underwent technically successful endovascular stenting. Following EVT, 76.7% (33/43) of patients had no persisting neurological deficits. Nine (20.9%) patients were found to have new cerebral infarcts on post-EVT imaging. In-hospital mortality was reported for 6 patients (14%), 4 of whom were found to have tandem cervical ICA and intracranial occlusions.

Conclusion: EVT is likely a technically viable alternative treatment for patients with perioperative acute neurologic deficits after CEA. However, most of the literature available comes from case series, thereby limiting the quality of evidence. Improved reporting of standard stroke outcome measures may help to inform the implementation of EVT and repeat CEA for acute ischemic symptoms after CEA.

Objective: Artificial intelligence (AI) holds promise for advancing neuroendovascular therapy through device evaluation, but its application in real-world clinical settings remains limited. We aimed to validate the feasibility of AI-based quantitative device evaluation during actual procedures by assessing the stability of the Rist radial access guide catheter (Medtronic, Dublin, Ireland), a novel device designed for the increasingly adopted transradial approach (TRA), during flow diverter stent (FDS) placement.

Methods: We retrospectively analyzed 4 cases of FDS placement using Rist via the TRA. Rist was tracked in recorded fluoroscopic videos using the AI technology of Neuro-Vascular Assist (iMed Technologies, Tokyo, Japan). The movement distance of Rist during FDS placement was calculated as a stability indicator.

Results: All procedures were successfully completed without any complications. Rist was introduced from the radial artery and positioned in the distal internal carotid artery. The maximum movement distances of the Rist during the procedures were 3.36, 6.63, 1.79, and 0.33 mm for each case, respectively, with an average of 3.03 mm. The maximum movement distances per minute were 1.68, 2.34, 1.19, and 0.46 mm/min, respectively, with a mean of 1.42 mm/min. These measurements suggest sufficient stability for the FDS procedures.

Conclusion: This study demonstrates the feasibility of using AI technology to quantitatively analyze Rist stability in TRA procedures. To the best of our knowledge, this is the 1st clinical evaluation of device function in a clinical setting using AI technology. Further studies with more cases are required to validate these findings. This method is promising for real-world device evaluation and development.

Objective: Medium vessel occlusions (MeVOs) during acute ischemic stroke present challenges due to their distal occlusion sites. Furthermore, MeVO cases with tortuous extracranial vessels are complex, and effective management techniques are lacking. This study reports the utility of combining a 6-French distal access catheter with a low-profile aspiration catheter, guiding catheter, and microcatheter to establish a quadruple coaxial system for treating MeVOs with tortuous extracranial vessels.

Methods: We retrospectively reviewed data from mechanical thrombectomy cases with MeVO at our institution between March 2022 and February 2024. A total of 81 patients were enrolled, and 5 patients were treated using the quadruple coaxial system. The primary efficacy outcome was the first pass effect (FPE), and the rate of successful recanalization, determined by the expanded thrombolysis in cerebral infarction (eTICI 2b/3) at the end of treatment. The safety assessment included hemorrhagic and procedure-related complications.

Results: Of the 81 enrolled patients, 5 patients were treated using the quadruple coaxial system. Three men and 2 women, with a mean age of 77 years, were included in this study. The median baseline National Institutes of Health Stroke Scale score was 10 points, and a tissue plasminogen activator was administered to 2 patients. Four patients had M2 occlusions, and 1 patient had a P2 occlusion. In 4 cases, the guiding system could not be advanced distally because of extracranial vessel tortuosity. The quadruple coaxial system achieved a significantly higher rate of FPE (80% vs. 30%; P = 0.0401) than the standard coaxial system, with no postoperative intracerebral hemorrhage or procedure-related complications.

Conclusion: The quadruple coaxial system is a valuable approach for treating MeVOs with severe extracranial vessel tortuosity. This system offers a reliable and safe treatment modality when a guiding system cannot be advanced distally.

Objective: This study aimed to investigate the difference in outcomes after emergent stenting with antiplatelet therapy for large vessel occlusion (LVO) stroke in patients with and without prior intravenous tissue plasminogen activator (IV tPA).

Methods: Patients who arrived at our hospital within 4.5 h of symptom onset and underwent endovascular therapy (EVT) for LVO between January 2015 and March 2023 were analyzed retrospectively. Patients were included if they underwent stenting for atherosclerotic lesions or arterial dissection with antiplatelet therapy during EVT. The safety and clinical outcomes were compared between patients who received IV tPA before EVT (IV tPA group) and those who did not (no-IV tPA group). The primary outcome was symptomatic intracranial hemorrhage (SICH) within 48 h of EVT.

Results: Overall, 54 patients were included in the analysis, with a median age of 72 years (interquartile range [IQR]: 53–74); 41 (76%) were women. The median pre-stroke modified Rankin Scale (mRS) score was 0 (IQR: 0–2), and the median National Institutes of Health Stroke Scale (NIHSS) score was 7 (IQR: 1–21). These patients underwent emergent stenting with antiplatelet therapy during EVT, with stenting performed in the cervical carotid artery and intracranial artery in 38 and 16 patients, respectively. Thirty-one of 54 patients received IV tPA before EVT. Sex, age, NIHSS score on admission, or Alberta Stroke Program Early Computed Tomographic Score on non-contrast CT did not differ significantly between the IV tPA and no-IV tPA groups. Final modified thrombolysis in cerebral infarction scores ≥2b were achieved more frequently in the IV tPA group than in the no-IV tPA group (97% vs. 87%; p = 0.30). SICH (13% vs. 0%; p = 0.13) and any intracranial hemorrhage (ICH) (29% vs. 8.7%; p = 0.09) occurred more frequently in the IV tPA group than in the no-IV tPA group. The rate of achieving mRS scores of 0–2 at 3 months after stroke onset was lower in the IV tPA group [11 (35%) vs. 13 (57%); p = 0.17].

Conclusion: Among patients who received emergent stenting with antiplatelet therapy, successful reperfusion was achieved more frequently in the IV tPA group than in the no-IV tPA group, although the former exhibited a higher SICH rate and worse functional outcomes. These findings suggest that prior IV tPA administration may increase the risk of hemorrhagic complications in cases requiring emergent stenting with antiplatelet therapy.

Objective: The implantation of stents in the cerebral arteries for aneurism exclusions requires the administration of dual antiplatelet therapy. This medication increases the haemorrhage risk, while some patients develop a phenomenon called “high on-treatment platelet reactivity,” exposing to the material thrombosis. The focus on the platelet function monitoring in this context is key to the success of this procedure, allowing for identification of the different population of patients for the adjustment of the prescription for which antiplatelet therapy to use, to get the best balance between the prevention of material thrombosis and haemorrhage risk. This study focuses on the use of platelet function monitoring with Multiplate (Roche, Boulogne-Billancourt, France), in the context of a prescription of clopidogrel and its possible replacement by ticagrelor for resistant patients.

Methods: The study is an observational retrospective cohort monocentric study. Patients were sampled for a Multiplate analysis with no antiplatelets treatment, then the day before the procedure, a new Multiplate analysis is proceeded with after 5 days of clopidogrel and aspirin. If adenosine diphosphate (ADP) test was above 300 area under the curve on Multiplate, it was decided to introduce ticagrelor. The primary endpoint was the occurrence of thromboembolic or haemorrhagic events during the first 30 days postoperatively.

Results: 104 patients treated electively with a stent for an intracranial aneurysm were included from January 2016 to June 2020; 77 patients were classified as responder to clopidogrel and 27 had to be switched from clopidogrel to ticagrelor; 9 patients under clopidogrel (8.6%) had an ischaemic event and 1 under ticagrelor (1%). No patient had a haemorrhagic event under clopidogrel and 3 under ticagrelor (2.8%). Comparing clopidogrel and ticagrelor group regarding ischemic or haemorrhagic event endpoints, the difference was not statistically significant: (p = 0.37), but statistically significant regarding fatal event (p = 0.02) in disfavour of ticagrelor.

Conclusion: The use of platelet function monitoring makes it possible to determine the therapeutic effectiveness of P2Y12 inhibitors, and thus to provide the most appropriate antiplatelets treatment for the patient when an intracranial stent is placed.

Objective: Middle meningeal artery embolization (MMAE) has emerged as a promising treatment, both as an adjunct to surgery and as a primary treatment for chronic subdural hematoma (cSDH). Here, we evaluate the efficacy of MMAE following surgery in reducing the likelihood of reoperation in patients requiring early introduction of antithrombotics.

Methods: From our prospectively collected registry of patients with cSDH, we identified patients treated with surgical evacuation, either in combination with or without MMAE. Patients were included if they had a clinical indication requiring early antithrombotics within 7 days of surgery. The primary outcome was the rate of reoperation. The secondary outcomes included recurrence in midline shift or changes in cSDH width based on imaging findings.

Results: Among 43 patients (53 total cSDHs) who met the inclusion criteria for the study, the median age was 71 years, 13% were female, the mean SDH thickness was 17.9 mm, and the most commonly used postoperative antithrombotic was aspirin. Sixteen cSDHs in 13 patients were treated with MMAE + surgery, while 37 cSDHs in 30 patients were treated with surgery alone. There was no difference in reoperation rates between the 2 groups (8.1% vs. 0%, surgery alone vs. surgery + MMAE, p = 0.55), nor in the rate of recurrence (24.3% vs. 12.5%, surgery alone vs. surgery + MMAE, p = 0.47).

Conclusion: In this single-center cohort study, we found no clear benefit in reduced rates of reoperation or recurrence for adjunctive MMAE in patients with cSDH treated with surgical evaluation. Despite this, encouraging trends were observed in the MMAE + surgery group.

Objective: As a solution to the shortage of and overwork among physicians, task shifting and task sharing have been proposed for health-care professionals. This study aimed to investigate the role of nurse practitioners (NPs) in neurovascular interventions and evaluate the validity of task shifting in our institute.

Methods: Medical records from 684 neurovascular intervention cases from 2020 to 2023 were retrospectively reviewed, and the tasks performed by NPs were investigated. Additionally, the procedure times between cases in which NPs acted as the first assistant alongside a physician (NP + physician group) and those in which 2 physicians performed the procedure (physician + physician group) were compared.

Results: The main tasks performed by NPs included preoperative checks, assistance during the procedure, postoperative care, the initial handling of complications, and inputting orders. No significant differences in procedure times were found between the NP + physician and physician + physician groups.

Conclusion: NPs showed potential for task shifting in perioperative neurovascular interventions, particularly in assisting, providing care, inputting orders, and initially handling complications. However, further discussions and improvements are needed regarding task shifting in emergency cases and work arrangements for NPs.

Objective: Traumatic carotid-cavernous fistula (TCCF) is a rare neurovascular condition that occurs after blunt head trauma. This condition accounts for approximately 4% of traumatic cerebrovascular injuries. Various symptoms can be observed in TCCF, and aggressive treatment is frequently required. Herein, we reviewed the treatment of TCCF in our hospital.

Methods: We retrospectively reviewed patients with TCCF between December 2021 and May 2023. The physical findings, clinical images, and surgical details of patients were investigated.

Results: Three men and 1 woman were included. Only 1 case was diagnosed with CCF using initial 3D-CTA; the other 3 were diagnosed after admission using DSA. All patients received endovascular treatment; 2 were initially treated with transarterial embolization, and the other 2 were treated with transvenous embolization, although 1 case of transarterial embolization required additional treatment with transvenous embolization. Complete occlusion was achieved in all cases. Two of the cases were accompanied by skull base fractures, both of which were middle fossa fractures.

Conclusion: TCCF is caused by direct injury to the internal carotid artery and can be accompanied by skull fractures or vessel wall damage as a result of shear force. We should suspect TCCF, especially when a skull base fracture is detected, even if the initial 3D-CTA shows no evidence of TCCF. Treatment for TCCF is mainly endovascular; however, the specific treatment approach should be determined for each case based on various factors, including vessel anatomy.

Objective: Insertion of a guiding catheter (GC) system into the desired arterial site is crucial in mechanical thrombectomy (MT). This study assessed the factors of difficult GC access to the target carotid artery in patients with acute ischemic stroke in the anterior circulation.

Methods: In total, 174 patients who had undergone MT were retrospectively reviewed. The incidence of patients who could not undergo GC insertion to the target carotid artery, as well as the characteristics and outcomes of patients requiring a longer groin puncture-to-GC insertion time, were examined. The patients were divided into 3 groups based on the time from groin puncture to insertion into the target carotid artery: group A, within 10 min; group B, within 10–20 min; and group C, >20 min. In this study, the transfemoral catheter access was the primary option, and the approach site was changed based on the operator’s discretion. Successful reperfusion was defined as modified Thrombolysis in Cerebral Infarction grade ≥2B. A favorable outcome was defined as a modified Rankin Scale score of 0–2.

Results: Catheterization of the target carotid artery could not be performed in 8 (4.6%) patients, who were older and more likely to be female. The proportion of patients with a height ≤150 cm and the percentage of patients with a type III arch and/or tortuous common carotid artery (CCA) were high. The approach was changed in 4 (2.3%) patients, and GC insertion was successful in all cases. A significant difference was observed among the 3 groups in terms of age and the percentage of patients with a type III arch and/or CCA tortuosity and internal carotid artery occlusion. In addition, the time from groin puncture to recanalization significantly differed. The recanalization rate and the 90-day favorable outcome rate were significantly lower in patients with a groin puncture-to-GC insertion time >20 min.

Conclusion: We need to make an effort to insert the GC within 20 min while actively considering changes in the approach, particularly in older patients and those with a type III arch and/or tortuous CCA.

Objective: We retrospectively examined the risk factors for early recurrence in patients with ruptured anterior communicating artery (AcomA) aneurysms who underwent coil embolization.

Methods: Forty-four patients with ruptured AcomA aneurysms who underwent coil embolization between January 2012 and June 2021 were included. Patient backgrounds, anatomical features, intraoperative anticoagulation, and radiological findings before and after treatment were reviewed retrospectively. Univariate analysis was performed separately for each item investigated in the early recurrence (ER) and non-early recurrence (NER) groups. Additionally, the relationship between changes in embolic status (Raymond-Roy classification [RRC]) from immediately after surgery to 2 weeks later and severity of disease was investigated.

Results: Re-treatment was performed in a total of 8 (18.2%) cases. Two cases were detected and treated in the chronic phase with no re-rupture. In the ER group, 6 (13.6%) cases had RRC class 3 filling without evidence of coil compaction on digital subtraction angiography performed 2 weeks after the initial embolization, and were re-treated. The mean intraoperative activated clotting time (ACT; p = 0.0226; NER median 189.5 s, ER median 149 s), contralateral A1 diameter (p = 0.0264; NER median 0.85 mm, ER median 0.26 mm), and volume embolization rate (VER; p = 0.02, NER median 35.57%, ER median 20.86%) were significantly lower in the ER group. The more severe the Hunt and Hess grade, the worse the embolic condition (RRC) tended to be after 2 weeks (p = 0.0339).

Conclusion: In this study, factors such as low intraoperative ACT, low VER, contralateral A1 hypoplasia, and condition severity may be associated with early recurrence after acute coil embolization for ruptured AcomA aneurysms.

Objective: In medically refractory idiopathic intracranial hypertension (IIH), venous sinus stenosis (VSS) stenting has been an effective treatment modality. Among patients who experience recurrent symptoms and develop new stenosis, the optimal treatment strategy is unknown. The aim of this study was to investigate the role of rescue re-stenting in patients with recurrence after prior successful stenting.

Methods: This was a single center, retrospective review from a prospectively maintained IIH registry. Between 2012 and 2023, patients who underwent interventions for confirmed IIH and angiographically demonstrable VSS were included. The cohort was divided into those who underwent a single stenting procedure (single stent group) and those who underwent re-stenting due to recurrence of symptoms and new angiographic stenosis (re-stent group).

Results: Ninety seven patients were included: 87 in the single stent group and 10 in the re-stent group, with a median age of 32 (interquartile range 26–38). 94% were female. Both groups had similar baseline demographic and clinical characteristics. There was similar improvement in papilledema and tinnitus. Headache improvement was greater in the single stent group at 6 weeks (88.4% vs. 60.0%, p = 0.04, single vs. re-stent group), but similar at 6 months post-procedure. For visual disturbances, there was similar improvement at 6 weeks, but greater improvement in the single stent group at 6 months post-procedure (86.8% vs. 75.0%, p = 0.04, single vs. re-stent group). None of the re-stented patients required rescue ventriculoperitoneal shunt placement.

Conclusion: Re-stenting among IIH patients with recurrent symptoms after initial successful VSS stenting is feasible with similar efficacy in improving symptoms.

Objective: Although vagal paragangliomas (VPs) and carotid body paragangliomas (CBPs) are both neck paragangliomas, they have different surgical risks and clinical courses. In this report, we investigated the feeding arteries of VPs compared with CBPs, with an aim to better differentiate these tumors and improve our understanding of their angioarchitecture.

Methods: We conducted a retrospective analysis of angiography data from 3 cases of VPs and 10 tumors from 9 cases of CBP. For each case, we evaluated the level of the vertebral body corresponding to the upper margin of the tumor, the tumor size, the arterial supply of the tumor, the topological relationship between the external carotid artery and internal carotid artery and the tumor, the details of preoperative embolization, and the incidence of postoperative neurological deficits.

Results: In all 3 cases of VPs, the blood supply originated from the occipital, vertebral, and ascending pharyngeal arteries. By contrast, among the 10 CBP tumors, 3 were supplied by the occipital artery, 1 was supplied by the vertebral artery, and all 10 were fed by the ascending pharyngeal artery. VPs, when compared to CBPs, exhibited larger tumor sizes, a higher positioning of the upper margin of the tumor, and a lack of splaying of the internal and external carotid arteries, compressing both forward. Additionally, preoperative embolization was frequently performed in cases of VPs. Furthermore, the postoperative occurrence of complications such as hoarseness and vocal cord paralysis was also higher.

Conclusion: VPs originate from the inferior ganglion of the vagus nerve, which is chiefly nourished by the vertebral artery. This original arterial distribution may explain the angioarchitecture observed in this study. This study may facilitate the better understanding of the VP angioarchitecture and safe and efficient embolization for them.

Objective: Computed tomography (CT) and magnetic resonance imaging of cerebral perfusion are useful in determining the indication of mechanical thrombectomy (MT) for acute ischemic stroke. RAPID (iSchemaView, Menlo Park, CA, USA) is the most common software for analyzing brain perfusion images worldwide, but various other software are also available. The optimal threshold value for each software is different, and each has its characteristics. This study investigated the relationship between the quantitative evaluation of ischemic core volume (ICV) and the Alberta Stroke Program Early CT Score (ASPECTS) using CT Perfusion 4D (GE Healthcare Inc., Milwaukee, WI, USA), a software used in our hospital.

Methods: Among patients who underwent MT between April 2015 and February 2023, those with modified Rankin Scale: 0–2, obstruction by embolic mechanism, and thrombolysis in cerebral infarction: 2b or higher were selected retrospectively. Patients with middle cerebral artery M1 segment (M1) and internal carotid artery (ICA) occlusions (90 and 46 patients) were included. We quantitatively analyzed ICV at relative cerebral blood flow (rCBF) <20% and cerebral blood volume (CBV) <1 mL/100 g and evaluated the relationship with ASPECTS scores in 3 groups: M1 + ICA, M1, and ICA occlusion groups.

Results: The median ICV was rCBF <20%: 44.7 cm³ and CBV <1 mL/100 g: 34.6 cm³, and there was no statistically significant difference between the 2 groups (p = 0.23). There was a negative correlation between ICV and ASPECTS scores in each occlusion group in all groups.

Conclusion: The quantitative evaluation of ICV at rCBF <20% and CBV <1 mL/100 g was negatively correlated with the ASPECTS score in GE’s CT Perfusion imaging analysis software.

Objective: Complications in neuroendovascular therapy for cerebral aneurysm (AN) affect the clinical course of patients. Patient conditions, operating procedures, and operator expertise were highlighted as risk factors for complications. These risk factors often combine and constitute particularly strong risks, resulting in a worsened clinical course. In this study, we performed a multifactorial assessment of complication risks in neuroendovascular therapy.

Methods: We analyzed patient data from the Japanese Registry of NeuroEndovascular Therapy 3, which is a nationwide retrospective cohort study of neuroendovascular procedures conducted between 2010 and 2014. Patients who underwent coil embolization for a ruptured anterior communicating artery (Acom) AN, an internal carotid artery-posterior communicating artery (IC-PC) AN, or basilar artery bifurcation (BA-bif) AN were included in this analysis. Information on 16 explanatory variables and 1 objective variable for each patient was obtained from the dataset as nominal variables. The explanatory variables consisted of patient factors, procedural factors, and an operator factor. The objective variable was whether the following complications occurred: intraprocedural bleeding, postprocedural bleeding, and procedure-related infarction. The specific situations involving multiple risk factors associated with high complication rates were identified using a programmed method. The impact of the absence of a supervising physician was also assessed.

Results: A total of 2971 patients were analyzed. The complication rates for patients with Acom ANs, IC-PC ANs, and BA-bif ANs were 12.9%, 10.2%, and 13.7%, respectively. A total of 15 specific situations were identified as follows: 3 related to an Acom AN, with complication rates ranging from 19.3% to 20.3%; 4 related to an IC-PC AN, with complication rates ranging from 15.6% to 17.9%; and 8 related to a BA-bif AN, with complication rates ranging from 20.6% to 33.3%. In 4 of these situations, the absence of a supervising physician significantly impacted complication rates. For instance, the complication rate for patients with IC-PC AN treated under local anesthesia was 16.0% overall, but it was 23.8% without supervising physicians.

Conclusion: Multifactorial assessment based on patient, procedural, and operator factors provides more reliable risk estimations and will help improve the clinical course.

Objective: Mechanical thrombectomy (MT) is an important procedure in the treatment of acute cerebral infarction, and its effectiveness depends largely on timely intervention after the onset. In the United States, a tiered accreditation system of stoke centers has been established to provide MT efficiently. In Japan, however, despite the large number of medical institutions performing MT, the establishment of a tiered accreditation system has yet to be seen. The low number of cases treated per institution raises concerns about the economic sustainability of MT in Japan because significant capital and human resource investment are required. This study aims to investigate the cost structure of MT procedure and the break-even point in 2 different hospital settings in Japan.

Methods: We conducted a detailed cost analysis of MT at 2 distinct hospitals: Hospital A, a large public hospital in a government-designated city, and Hospital B, a private non-profit hospital in the Tokyo metropolitan area. Data collection involved face-to-face interviews with department heads and a structured survey based on the Japanese Hospital Accounting Standards, focusing on material, labor, and facility-related costs. Break-even points were calculated considering both fixed and variable costs, with adjustments made for the shared use of facilities in Hospital B.

Results: The total cost per case was 349256 yen in Hospital A and 245150 yen in Hospital B, respectively. The total cost per case was elevated to 559866 yen assuming only MT was performed at Hospital B. This figure was significantly higher than the reimbursement price of MT (331500 yen). The number of procedures needed to exceed the break-even point for MT was approximately 290 cases per year in Hospital A and 125 cases per year in Hospital B, respectively.

Conclusion: We conducted a break-even analysis of MT based on an interview survey. The number of cases required to cross the break-even point for MT alone was much higher than the actual number of MT procedures being performed in the 2 hospitals.

Objective: Symptomatic vasospasm (SVS) affects the outcomes of patients with subarachnoid hemorrhage (SAH) and often requires endovascular treatment. Hyponatremia is a predictor of SVS; however, no guidelines have recommended an absolute serum sodium value for SVS prevention. This study aimed to identify factors that influence SVS in patients with low-grade SAH and determine a specific threshold of serum sodium level that predicts SVS.

Methods: We conducted a multicenter, retrospective study of 216 patients with aneurysmal SAH grades I–III (World Federation of Neurological Societies scale). Patients were divided into the endovascular treatment-needed vasospasm (etVS) group (n = 29) and non-etVS group (n = 187). The minimum serum sodium level (minNa) was determined in the initial 2 weeks after SAH onset.

Results: The minNa of the etVS group (median 132 mmol/L) was significantly lower compared to that of the non-etVS group (median 136 mmol/L) (p <0.001). The receiver operating characteristic curve revealed that a threshold minNa of 133 mmol/L predicted the development of etVS (sensitivity 0.797 and specificity 0.552), and the area under the curve was 0.703 (95% confidence interval [CI]: 0.591–0.815). The odds ratios for etVS in patients with a minNa ≤128 mmol/L and 129–132 mmol/L were 6.79 (95% CI: 2.24–20.51) and 2.96 (95% CI: 0.90–9.73), respectively, when compared to those with a minNa 133–136 mmol/L.

Conclusion: Serum sodium levels were a predictor of etVS in patients with low-grade SAH. This is the first study to identify a threshold of serum sodium level for predicting etVS, aiding clinicians in setting a management goal for SVS prevention.

Objective: Thrombectomy is the standard recanalization treatment for acute ischemic stroke (AIS) due to large vessel occlusions (LVO). However, thrombectomy was validated using a few brands of devices. New types of thrombectomy devices have been developed, and assessing their safety and efficacy is essential. This study aimed to evaluate the safety and efficacy of thrombectomy with the Aperio Hybrid stent retriever (Acandis, Pforzheim, Germany) in the treatment of patients with AIS due to anterior circulation LVO.

Methods: This was a multicenter registry of thrombectomy in the treatment of stroke due to anterior circulation LVO. Between January 2022 and January 2024, a total of 128 patients were included.

Results: The mean procedure time was 62 minutes. The rates of the main outcomes were recanalization (extended treatment in cerebral ischemia 2b-3) 102/128 (79.7%), symptomatic intracranial hemorrhage 9/128 (7.0%), good clinical outcome (modified Rankin Scale = 0–2) 67/128 (52.3%), and mortality 24/128 (18.7%) at 3 months.

Conclusion: This study showed that, in a multicenter real-life scenario, the Aperio hybrid stent retriever was safe and effective for thrombectomy of anterior circulation strokes. The outcomes of this study were similar to those of previous large thrombectomy studies.

Objective: The prognosis of patients with subarachnoid hemorrhage (SAH) who also develop cardiopulmonary arrest (CPA) is highly unfavorable, and hence they are often not aggressively treated. Presently, the therapeutic indications and factors that affect the prognosis of patients who experienced CPA remain unclear. Therefore, we analyzed SAH patients who experienced CPA, comparing the characteristics of the patients who survived with those who did not.

Methods: The 36 patients were divided into the survivor group (n = 4) and the dead group (n = 32). The patient’s age, sex, location of the aneurysm, the presence of intracranial hematoma, duration of cardiopulmonary resuscitation (CPR), the presence/absence of bystanders, initial electrocardiogram waveform, recovery of brainstem reflexes with motor response, and administration of vasopressors were compared between the 2 groups.

Results: There were no significant differences in age, sex, location of the aneurysm, and presence of intracranial hematoma between the 2 groups. More than 90% of patients in the dead group had a non-shockable rhythm on the initial electrocardiogram waveform. The duration of CPR in the survivor group tended to be shorter than that in the dead group. Bystander CPR was performed on 14 patients, including all 4 of the survivors. All patients in the survivor group achieved recovery of brainstem reflexes with motor response. In the survivor group, all patients either did not need or only transiently needed the administration of vasopressors after the return of spontaneous circulation (ROSC).

Conclusion: Our analysis suggested the following as favorable prognostic factors in SAH patients with CPA: shockable arrhythmia on the initial electrocardiogram waveform, young age, bystander CPR, a short time from CPA to ROSC, recovery of brainstem reflexes with a motor response, and no or transient use of vasopressors. Our results indicate that aggressive treatment may be indicated in SAH patients with CPA who have stable vitals and show improvements in neurological symptoms.

Objective: Cerebral venous sinus thrombosis (CVST) is a rare but serious condition that can cause intracranial hypertension and hemorrhage. Common risk factors include thrombophilia and oral contraceptive use, but jugular Eagle syndrome—caused by an elongated styloid process compressing the internal jugular vein—is an uncommon yet clinically significant etiology.

Case Presentation: A 44-year-old woman presented with severe right-sided headache, neck pain, and visual disturbances after cervical spine manipulation. Imaging revealed extensive CVST with venous congestion hemorrhage, and jugular Eagle syndrome was confirmed. Symptoms persisted despite anticoagulation, but her headache improved after successful endovascular thrombectomy. Styloidectomy was considered for long-term management.

Conclusion: Jugular Eagle syndrome is a rare cause of CVST. Anticoagulation remains first-line, but thrombectomy may be required in refractory cases, and surgical styloidectomy should be considered for definitive management.

Objective: Nickel allergy is one of the most common forms of metal hypersensitivity, yet its relevance to neuroendovascular therapy has rarely been reported. We describe 3 cases of unruptured intracranial aneurysms in patients with confirmed nickel allergy, and review the literature to highlight safe endovascular management strategies.

Case Presentation: Three female patients (2 in their 70s and 1 in her 60s) were incidentally diagnosed with unruptured intracranial aneurysms located at the internal carotid artery (n = 2) and the vertebral artery (n = 1). All patients tested positive on patch testing for nickel. To minimize allergic risk, devices with low nickel content were chosen, including bare platinum coils (i-ED coils; Kaneka Medix, Osaka, Japan) and a flow diverter (Surpass Evolve; Stryker, Kalamazoo, MI, USA). Endovascular treatment was completed without perioperative complications, and no allergic reactions were observed during a mean follow-up of 12.7 months. Corticosteroids were not administered in any of the cases.

Conclusion: Endovascular treatment of unruptured intracranial aneurysms in patients with nickel allergy can be performed safely by avoiding devices with high nickel content and by performing preoperative allergy testing. Awareness of device materials is critical for preventing adverse reactions and ensuring favorable outcomes.

Objective: Bridging veins adjacent to the jugular foramen (JF-BVs) are rare drainage pathways in dural arteriovenous fistulas (DAVFs). We report a unique case of a transverse-sigmoid sinus DAVF (TS-DAVF) with retrograde venous drainage via a JF-BV, successfully treated with selective transvenous coil embolization.

Case Presentation: A man in his 60s presented with a 2-month history of right-sided pulsatile tinnitus. Cerebral angiography revealed a high-grade TS-DAVF supplied by branches of the external carotid and vertebral arteries. Venous drainage involved a compartmentalized portion of the sigmoid sinus that drained into a JF-BV, continuing through the retrotonsillar and inferior vermian veins to the confluence of sinuses. Additional reflux occurred via the ipsilateral and contralateral TSs, the superior petrosal sinus, and cortical veins through the vein of Labbé. The right internal jugular vein was occluded at the cervical level. A transvenous approach via the contralateral jugular vein allowed catheter navigation via a compartmentalized portion of the jugular bulb separated by trabecular septations to reach the JF-BV. After superselective angiography confirmed its course, coil embolization was performed from the lateral medullary vein junction back to the sinus. Shunt flow was completely occluded while preserving normal cortical venous drainage. The patient’s tinnitus resolved without neurological deficits.

Conclusion: To the best of our knowledge, this is the first reported case of selective transvenous coil embolization of a JF-BV draining a TS-DAVF. Preprocedural imaging with selective angiography and a multi-catheter system enabled safe and effective treatment. Selective JF-BV embolization may represent a viable therapeutic option for DAVFs with catheter-navigable compartments.

Objective: Subclavian artery (SA) stenoses are typically asymptomatic because of well-developed collateral circulation. In patients who have undergone coronary artery bypass grafting (CABG) using the internal thoracic artery (ITA), SA stenosis can induce coronary–subclavian steal syndrome and cause myocardial ischemia. Therefore, immediate interventions are required for such a dangerous condition. Furthermore, SA stenosis involving the origin of the vertebral artery (VA) requires simultaneous protection of the origin of the VA due to the risk of acute occlusion during the balloon angioplasty of the SA. We report a successful treatment of SA stenosis involving the origin of the VA following CABG using ITA, adopting the kissing balloon technique.

Case Presentation: A 68-year-old man with a history of CABG using the left ITA for acute myocardial infarction developed severe left SA stenosis extending to the origin of the dominant left VA. Percutaneous transluminal angioplasty and stenting using the kissing balloon technique were performed to avoid the occlusion of the origin of the VA. Successful dilatation of the SA was achieved with good patency of the VA and the ITA. Postoperative imaging confirmed improved perfusion of the ITA bypass and the VA. The patient tolerated the procedures well without any neurological deficits, and follow-up 3D CTA obtained 3 months after the procedure demonstrated good patency of the SA, ITA, and VA.

Conclusion: This case highlights the safety and effectiveness of the kissing balloon technique in the treatment of complex SA stenosis involving the origin of the VA following CABG using the ITA. The kissing balloon technique enables simultaneous dilation of SA lesions and protection of the VA.

Objective: Medial tentorial dural arteriovenous fistulas (DAVFs) are rare lesions that may cause intracranial hemorrhage or non-hemorrhagic symptoms due to venous congestion from retrograde deep venous drainage. We report a case of a medial tentorial DAVF presenting with cognitive decline and impaired consciousness, successfully treated with transvenous embolization (TVE) and straight sinus angioplasty, and complicated postoperatively by central diabetes insipidus (CDI).

Case Presentation: A 55-year-old man with diabetes mellitus presented with cognitive decline, disorientation, aphasia, and motor impairment without limb paralysis. CT revealed bilateral thalamic hyperdensities, and MRI showed thalamic and medial occipital hypointensities. CT venography demonstrated straight sinus occlusion. Angiography identified a tentorial DAVF fed by the posterior meningeal and tentorial arteries, draining into the superior vermian vein (Borden III, Cognard III). On day 3, TVE and straight sinus angioplasty achieved complete shunt obliteration. Postoperatively, serum sodium increased from 157 mEq/L on day 1 to 164 mEq/L on day 2, accompanied by thirst, polydipsia, and polyuria. Correction of hyperglycemia did not improve the symptoms. The absence of urine output reduction during water restriction and marked improvement after I-deamino-8-D-arginine vasopressin (DDAVP) confirmed CDI. DDAVP was tapered from day 58 and stopped on day 68 without recurrence. The patient was discharged on day 72.

Conclusion: To our knowledge, this is the first report of CDI after treatment of a medial tentorial DAVF. In patients with deep venous congestion, similar complications may occur. Careful postoperative monitoring of urine output and electrolytes is essential for early recognition and management.

Objective: Anterior condylar (AC) arteriovenous fistulas (AVFs) can form intraosseous shunted pouches, and recent reports have suggested the involvement of the jugular tubercle venous complex (JTVC). Transvenous embolization (TVE) via the AC vein (ACV) is considered the 1st-line treatment. This paper reports a case of an intraosseous AC-AVF successfully treated with TVE via a strategic detour through the posterior condylar vein (PCV).

Case Presentation: A 60-year-old woman was suspected of having a dural AVF during the examination for pulsatile tinnitus. Detailed preoperative imaging studies using 3D rotational angiography (3D-RA) and cone-beam CT (CBCT) led to the diagnosis of an intraosseous AC-AVF. We were unable to navigate the catheter through a potentially existing direct pathway to the intraosseous shunted pouch, as it was not visualized on intraoperative angiography. Finally, we were able to navigate by tracing a unique drainage detour involving the PCV visualized on angiography and perform selective TVE. Postoperatively, the shunt completely disappeared, and the pulsatile tinnitus resolved.

Conclusion: Detailed preoperative imaging studies using 3D-RA and CBCT, as well as the use of a thin intermediate catheter, may have enabled the unique approach. In intraosseous shunts, guiding through the visualized drainage route, even when it involves a detour, may represent the most reasonable primary strategy.

Objective: Persistent primitive hypoglossal artery (PPHA) is a rare vascular anomaly that can complicate carotid artery stenting (CAS) due to its role in posterior circulation perfusion. Embolic protection is required for both the anterior and posterior circulations, which increases procedural complexity. We present a novel approach utilizing double distal filter protection (DDFP) with a single guiding catheter.

Case Presentation: A 69-year-old man with symptomatic internal carotid artery stenosis (ICS) and coexisting PPHA underwent successful CAS using a DDFP strategy with a single guiding catheter. Two filter devices were deployed: 1 in the distal internal carotid artery and 1 in the PPHA. Stent delivery was achieved by temporarily retrieving the PPHA filter, followed by redeployment and post-dilation. No perioperative complications occurred. Imaging demonstrated adequate cerebral perfusion and high-risk plaque morphology, supporting the need for dual protection. The procedure minimized access-related risks and maintained perfusion throughout.

Conclusion: We successfully performed CAS in a patient with PPHA using a DDFP with a single guiding catheter technique. This technique may reduce procedural complexity while maintaining robust embolic protection, offering a safe alternative to traditional dual-catheter strategies.

Objective: Moyamoya disease and dural arteriovenous fistulas (dAVFs) are both rare conditions, and their coexistence is extremely uncommon. The causal relationship between moyamoya disease and cavernous sinus dAVFs (CS-dAVFs) remains unclear. We report a successfully treated case of CS-dAVF in a patient with moyamoya disease, focusing on vascular structural changes and potential pathophysiological associations.

Case Presentation: A 69-year-old man with a history of moyamoya disease presented with progressive left ocular symptoms. Imaging studies, including 3D-DSA, revealed a CS-dAVF supplied by multiple feeders and draining into the superior ophthalmic and angular veins. Compared to previous imaging, the progression of moyamoya disease was evident, with worsening middle cerebral artery stenosis and increased collateral vessels. Superselective transvenous embolization was performed under general anesthesia. Microcatheters were navigated into the affected venous structures, and coil embolization successfully obliterated the shunt. Postoperatively, the patient had significant symptomatic improvement, with no moyamoya-related complications, and was discharged on postoperative day 4.

Conclusion: To our knowledge, this is the first report of a successfully treated CS-dAVF in a patient with moyamoya disease. Superselective transvenous embolization was successfully performed, which led to a favorable outcome despite the presence of moyamoya disease.

Objective: Ruptured dissecting aneurysm of the basilar artery trunk is a rare condition associated with high morbidity and mortality. Due to limited data, definitive treatment options and long-term radiological outcomes remain unclear. This report presents the 11-year radiographic follow-up of a dissecting basilar artery trunk aneurysm that presented with severe subarachnoid hemorrhage (SAH) and was managed with 4 endovascular interventions, including coiling and overlapping Enterprise Vascular Reconstruction Device (Johnson & Johnson, Miami, FL, USA) stent placements.

Case Presentation: A 32-year-old male with World Federation of Neurosurgical Surgeons Grade V SAH was transferred to our institution for the treatment of a 4-mm sidewall aneurysm of the basilar artery trunk. The lesion was initially managed on Day 1 with balloon-assisted coiling using a double microcatheter technique, achieving satisfactory occlusion. However, progressive aneurysm enlargement necessitated a 2nd intervention on Day 14, during which additional coils were deployed and 2 overlapping stents were placed. As the aneurysm continued to expand, reaching 10 mm by Day 32, a 3rd coiling procedure was performed. A 4th intervention—entailing further coiling and the placement of 2 additional overlapping stents—was completed 4 months following the initial event. The patient recovered without neurological deficits. During an 11-year follow-up, which included annual MRA and a 5-year interval DSA, a small residual at the aneurysm base detected at the 5-year follow-up demonstrated a gradual increase in size by 1.0 mm over 6 years. Despite this growth, the patient remained clinically stable.

Conclusion: Sustained prevention of re-rupture in a basilar artery trunk dissecting aneurysm was achieved through multiple overlapping stents combined with coil embolization, although aneurysm recurrence was not entirely controlled. Further investigation into more definitive therapies—such as flow-diverting devices—is warranted to achieve durable, curative outcomes.

Objective: Arterial spin labeling (ASL) is a noninvasive MRI technique used to evaluate cerebral perfusion. Arterial transit artifact (ATA), which appears as high-signal areas proximal to vessel occlusion, may provide important diagnostic information, particularly when conventional angiographic visualization is limited. We present two cases of posterior cerebral artery (PCA) occlusion in which ATA detection via ASL played a critical role in guiding endovascular treatment.

Case Presentation: Case 1 involved a woman in her 70s who presented with right-sided numbness and visual field loss. MRA did not clearly delineate the left PCA; however, ASL revealed an ATA in the P3–4 territory distal to the angiographically confirmed P2 occlusion. CT perfusion confirmed hypoperfusion, and thrombectomy resulted in complete visual recovery. Case 2 involved a man in his 40s who experienced sudden-onset blindness. MRA indicated bilateral PCA occlusion, and ASL showed bilateral ATA(s). Following intravenous recombinant tissue-type plasminogen activator administration and left PCA thrombectomy, partial visual improvement was observed. On postoperative day 3, ASL again revealed an ATA in the right P3 segment, suggesting reocclusion. Emergency thrombectomy led to visual restoration.

Conclusion: These cases highlight the utility of ASL imaging and ATA detection in diagnosing PCA occlusion and monitoring treatment response. ASL provides a noninvasive, contrast-free complement to MRA in the acute stroke setting, particularly for the posterior circulation, where visualization is often limited. ATA may serve as a valuable imaging biomarker for identifying occlusion and reocclusion, aiding clinical decision-making.

Objective: We report a unique case of carotid artery stenting (CAS) conducted via direct puncture of an aortic arch graft in a patient who underwent total arch replacement (TAR), complicated by carotid artery dissection.

Case Presentation: A 72-year-old woman underwent TAR for an ascending aortic aneurysm. Aortic dissection extending to the right carotid artery was detected immediately after the aortic arch graft anastomosis, which resulted in severe stenosis and decreased cerebral perfusion. Therefore, urgent revascularization was deemed necessary. The aortic arch graft was directly punctured, followed by the placement of 3 stents to seal the dissection. Postoperative imaging confirmed the restoration of blood flow without ischemic complications. The patient, who recovered without neurological deficits or cardiosurgical complications, has remained event-free for 3 years after the intervention.

Conclusion: Direct puncture of the aortic arch graft provides a reliable and rapid access route for CAS in patients undergoing carotid artery dissection following TAR. This method may serve as an alternative when conventional access is difficult. Antithrombotic therapy should be strictly controlled to avoid procedure-related complications.

Objective: Flow diverter placement across the ophthalmic artery carries a reported visual-impairment risk of about 1%, yet oculomotor nerve palsy following treatment of small paraclinoid aneurysms without mass effect has not been described. Our objective was to present a case of a transient oculomotor palsy following a flow diverter treatment for 6 and 2.5 mm paraclinoid aneurysms.

Case Presentation: A 57-year-old woman underwent flow diverter treatment for two left paraclinoid aneurysms measuring 6 and 2.5 mm. On the fifth post-operative day, she experienced blurred vision, mild left ptosis, and restricted adduction and elevation of the left eye, while pupillary function remained intact. The diagnosis of left pupil-sparing oculomotor palsy was made. Conservative management led to full resolution of symptoms within three months. Follow-up 3D rotational angiography demonstrated occlusion at the origin of the inferolateral trunk of the left internal carotid artery.

Conclusion: Oculomotor nerve palsy caused by flow diverter coverage of small internal carotid artery branches supplying the cranial nerves may be an under-recognized complication and warrants clinical attention. A review of the literature suggested an approximately 3% incidence of this complication, and we discussed the pathomechanism of the cranial nerve palsy caused by flow diverter treatment.

Objective: We report 2 cases of ruptured intracranial dissecting aneurysms that were successfully treated with a flow diverter (FD) stent in the subacute phase, following urgent stent-assisted coiling (SAC) embolization.

Case Presentation: Case 1: A 48-year-old male presented with a sudden-onset headache and altered consciousness. CT showed a diffuse subarachnoid hemorrhage (SAH). DSA revealed a right vertebral artery dissecting fusiform aneurysm (VADA). Considering that the perforating and anterior spinal arteries arose from the VADA, SAC was performed to preserve the perforating branch. Follow-up angiography revealed regrowth of the aneurysm without hemorrhage. Case 2: A 37-year-old male was involved in a car accident, followed by a sudden loss of consciousness. CT showed diffuse SAH, and DSA revealed a right internal carotid artery (ICA) blood blister-like aneurysm (BBA) on the anterior wall of the C2 portion. We performed SAC because of the difficulty in urgent high-flow bypass and trapping due to brain swelling. Follow-up angiography revealed regrowth of the aneurysm without hemorrhage. Each treatment involved SAC using the low-profile visualized intraluminal support (LVIS) stent (Terumo, Tokyo, Japan) and FD using the pipeline embolic device. The procedures were performed without complications.

Conclusion: To date, few studies on stepwise treatment with SAC and FD for refractory ruptured cerebral aneurysms, such as VADA and BBA of the ICA, have been reported. In addition to the cases reported, we also reviewed previous articles on treatment results, discussed antiplatelet therapy, and provided tips for the telescoping stent procedure.

Objective: Reports on embolization of the feeding arteries for vestibular schwannomas are limited, and studies addressing the tumor volume reduction effect of embolization are similarly scarce. Here, we present a case of a patient with vestibular schwannoma and associated ventricular enlargement, in which preoperative embolization led to substantial tumor volume reduction and subsequent improvement in ventricular enlargement.

Case Presentation: The patient was a 32-year-old man presenting with hearing loss, headache, nausea, unsteadiness, and loss of appetite. MRI displayed a left vestibular schwannoma with a maximum diameter of 38 mm and associated ventricular enlargement. Angiography displayed a hypervascular vestibular schwannoma with feeders from the left anterior inferior cerebellar artery (AICA) and the petrosal branch of the middle meningeal artery (MMA). Embolization was performed using 25% N-butyl cyanoacrylate for the AICA and 500–700-μm Embosphere microspheres diluted 60 times for the MMA. Symptomatic improvement was observed 2 days after the procedure. MRI conducted 4 days after the procedure showed a 19.8% reduction in tumor volume and mild ventricular shrinkage. The patient underwent tumor resection 7 days post-embolization and had a favorable postoperative course.

Conclusion: Although the tumor volume reduction effect of preoperative embolization does not always lead to an improvement in ventricular enlargement, our present case demonstrates that preoperative embolization can contribute to the improvement of ventricular enlargement through its volume reduction effect.

Objective: Mechanical thrombectomy is constantly advancing in terms of devices and techniques to enhance outcomes, and it is now commonly performed worldwide. Delayed stenosis is a potential complication that can occur following the procedure. However, its pathophysiology, risk factors, and time of onset remain unclear. We report 2 cases of delayed severe stenosis after mechanical thrombectomy.

Case Presentation: Case 1: A 70-year-old man was referred to our hospital with a right middle cerebral artery occlusion. We performed mechanical thrombectomy promptly. Complete recanalization was achieved after the 2nd thrombectomy attempt with no complications. Case 2: A 24-year-old man was sent to our hospital with an occlusion in his left middle cerebral artery. We quickly performed mechanical thrombectomy, successfully achieving recanalization after the 6th attempt. A post-procedural CT scan revealed an intracranial hemorrhage. In both cases, although no stenosis was observed the next day, significant delayed stenosis was discovered months later after mechanical thrombectomy. However, the patients remained asymptomatic.

Conclusion: Mechanical thrombectomy is a recognized treatment for acute ischemic stroke, but there are instances of delayed stenosis following the procedure. Excessive vessel injury caused due to thrombectomy may lead to delayed stenosis. This report emphasizes the importance of regular follow-up after mechanical thrombectomy, particularly in cases where there is a potential for substantial vascular damage due to thrombectomy.