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: 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: Giant anterior cerebral artery (ACA) aneurysms are rare and technically challenging to manage. Surgical approaches are highly demanding, and the associated complication rates are not necessarily low. Conventional endovascular techniques often fail to achieve durable occlusion. The Flow-Redirection Endoluminal Device (FRED; Terumo Neuro, Aliso Viejo, CA, USA) has demonstrated efficacy in other intracranial locations; however, its use in giant ACA aneurysms has not been previously reported.

Case Presentation: A 64-year-old woman presented with frontal lobe aphasia. Imaging revealed a giant thrombosed aneurysm in the left A1–A2 segment with perianeurysmal edema. She was treated with a FRED device. Due to severe deformation of the left A1 segment, a 5Fr SOFIASELECT distal access catheter (Terumo Neuro) was used to navigate the tortuous anatomy and facilitate device delivery. Complete occlusion of the aneurysm was confirmed at 5 months. MRI demonstrated progressive shrinkage of the aneurysm and resolution of edema, with no neurological deficits observed at 23 months.

Conclusion: This case suggests that giant ACA aneurysms may be successfully treated with flow diversion using the FRED. The use of a distal access catheter capable of reaching the A1 segment appeared to be important for achieving stable device deployment and complete occlusion, highlighting its potential role in complex anterior circulation interventions.

Objective: A tentorial dural arteriovenous fistula (DAVF) draining into the superior petrosal vein, also referred to as a petrous DAVF, is a Borden type 3 lesion with an aggressive natural history. Standard treatment options include surgical disconnection of the drainer or transarterial embolization (TAE). While the former requires an invasive craniotomy, the latter is associated with incomplete occlusion and a high complication rate. Transvenous embolization (TVE) has traditionally been considered challenging. We report a case of TVE performed through a tortuous pial vein using the retrograde pressure cooker technique (RPCT).

Case Presentation: A 38-year-old woman presented with right pulsatile tinnitus. Angiography revealed a petrous DAVF supplied by the petrous branch of the middle meningeal artery, the ophthalmic artery, and the inferolateral trunk. A TAE attempt failed due to the narrow and tortuous access of the eloquent feeder. Consequently, TVE was performed via right jugular access, with retrograde navigation of 2 microcatheters through the vein of Galen, basal vein of Rosenthal, and lateral mesencephalic vein. After coils were placed as a plug scaffold in the draining vein, Onyx 34 (Medtronic, Irvine, CA, USA) was injected under intentional systemic hypotension. This resulted in the occlusion of the foot of the drainer, the fistulous point, and the feeders adjacent to the fistula. Due to the significant resistance encountered and the associated risk of venous injury, the microcatheter used for Onyx injection was left in place. The patient’s symptoms resolved completely without any neurological deficit.

Conclusion: TVE using the RPCT achieved complete obliteration of a petrous DAVF. Further cases are needed to validate the feasibility and safety of this technique.

Objective: Formation of an aneurysm at the anastomosis site is a rare complication of superficial temporal artery–middle cerebral artery (STA-MCA) bypass for moyamoya disease (MMD). All 5 previously reported cases were treated with craniotomy, and no case of endovascular treatment has been reported to date. Here, we report a case in which endovascular treatment was performed for an anastomotic aneurysm that developed after STA-MCA bypass surgery for MMD.

Case Presentation: A 46-year-old woman with no relevant medical history developed a cerebral hemorrhage and was diagnosed with MMD. Bilateral STA-MCA bypass was performed to prevent recurrence of bleeding, and a de novo aneurysm was found at the right anastomosis site 1 year after the surgery. After a 2-year follow-up period, the size of the aneurysm and the diameter of the STA increased; therefore, treatment was initiated. Endovascular treatment was performed using the double-catheter technique. After coil embolization, the aneurysm was no longer visible, and no complications were observed.

Conclusion: Anastomotic aneurysms after STA-MCA bypass can be safely and effectively treated with endovascular therapy.

Objective: This case report describes the successful coil embolization of a direct carotid-cavernous fistula (d-CCF) caused by aneurysmal rupture in an older patient with residual aortic dissection, via direct puncture of the common carotid artery (CCA).

Case Presentation: A 95-year-old woman presented with progressive right periorbital swelling, pain, and eye redness. Cranial imaging revealed proptosis, dilated superior and inferior ophthalmic veins, and a ruptured aneurysm of the right internal carotid artery (ICA), leading to a diagnosis of d-CCF. Conventional endovascular access was not feasible due to residual aortic dissection extending from the brachiocephalic artery to the right CCA, despite prior stent graft placement. Under general anesthesia, a 6-Fr sheath was inserted directly into the distal CCA. Coil embolization was then performed using a balloon-assisted technique, targeting the cavernous sinus and the aneurysm. The procedure successfully occluded the fistula and preserved the ICA flow. Postoperatively, her ocular symptoms improved significantly, and she was discharged 1 week later without complications.

Conclusion: This case demonstrates that d-CCF can be safely and effectively treated with careful vascular evaluation and a tailored endovascular strategy, even in extremely old patients with difficult vascular access and complex aneurysmal anatomy.

Objective: The Woven EndoBridge (WEB), an intrasaccular device, is a new alternative to coils for the endovascular treatment of wide-neck bifurcation aneurysms. Selection of the correct size of the device is of utmost importance for successful treatment outcomes. We present a case of an unruptured cerebellar artery aneurysm that was successfully treated with WEB implantation, guided by a 3D silicone model for preoperative evaluation.

Case Presentation: A 67-year-old woman with no family history of cerebral aneurysms was diagnosed with an unruptured basilar-superior cerebellar artery (BA-SCA) aneurysm. The patient’s aneurysm was wide-necked with a dome of 8.1 mm, a neck of 6.5 mm, a height of 6.9 mm, and a volume of 287 mm³. In the preoperative simulation with 3D printed models, the WEB 9 × 4 mm device successfully preserved the SCA. Therefore, it was selected for treatment. Although the aneurysm had an angle of nearly 90° to the BA artery, the preoperative evaluation made it easy to guide the microcatheter and place the WEB device. The postoperative course was favorable and no new neurological symptoms were noted. Cerebral angiography performed 6 months after the procedure confirmed complete occlusion of the aneurysm.

Conclusion: Preoperative simulation with 3D printed models can help to plan device size selection and implantation position, thereby predicting intraoperative microcatheter behavior in advance.

Objective: We report a case of subarachnoid hemorrhage (SAH) due to the ruptured dissection aneurysm of the frontopolar artery (FPA), which was successfully treated with parent artery occlusion (PAO).

Case Presentation: A 42-year-old woman was brought to our hospital suffering from sudden severe headache and vomiting. Four days prior to admission, she experienced a mild frontal headache. Head computed tomography (CT) revealed SAH with a right medial frontal lobe hematoma. On the day of admission, we performed cerebral angiography, and a fusiform aneurysm was found in the FPA branching from the proximal right anterior cerebral artery (A1), which was suspected to be the dissection. We performed PAO for the right FPA. The patient was discharged with mRS:0 on the 27th day of admission. Several reports describe that the FPA usually bifurcate from the A2 segment, and it is rarely dissected. However, in our case, the FPA originated from the distal part of the A1 segment, and the dissection aneurysm of FPA ruptured.

Conclusion: To the best of our knowledge, this is the first reported case of SAH due to a ruptured dissection aneurysm of FPA treated by PAO.

Objective: Contrast-induced encephalopathy (CIE) is a rare complication of endovascular procedures with an incompletely understood pathophysiology. Its intraoperative detection under general anesthesia can be challenging. We present a case of CIE occurring during aneurysm embolization, demonstrating varying severity across procedures and suggesting that somatosensory evoked potentials (SEPs) may help in early recognition.

Case Presentation: A 63-year-old woman underwent endovascular coil embolization for a ruptured distal anterior cerebral artery aneurysm under general anesthesia, with intraoperative transcranial SEP monitoring. Contrast injection from the cervical internal carotid artery (ICA) during the procedure caused transient SEP attenuation, leading to mild post-procedural paresis and sensory impairment in the patient, both of which resolved within days. Six months later, DSA from the common carotid artery confirmed coil compaction. The patient underwent the examination and showed no signs of developing neurological symptoms. Repeat embolization was performed in the following month. During the 2nd procedure, contrast injection from the C1 segment of the ICA resulted in complete loss of left lower limb SEP. Immediately after the procedure, she exhibited mild left lower limb paresis and sensory impairment. Immediate postoperative cone-beam CT revealed contrast enhancement in the right hemisphere, leading to a diagnosis of CIE. On the following day, she developed left hemispatial neglect, along with worsening left hemiparesis and sensory impairment, despite no apparent abnormalities on MRI. The deficits improved with steroid therapy and were resolved by day 6.

Conclusion: Intraoperative SEP monitoring may be useful for the early detection of CIE during aneurysm embolization.

Objective: We report a patient with occlusion of the distal internal carotid artery (ICA), in whom angiography during mechanical thrombectomy revealed a shunt between the ICA and the cavernous sinus.

Case Presentation: A 79-year-old man with bile duct cancer, a liver abscess, septic shock, and atrial fibrillation presented to our hospital with sudden disturbance of consciousness, conjugate eye deviation, and right hemiplegia. A cranial CT revealed a hyperdense middle cerebral artery (MCA) and loss of gray-white matter differentiation, suggesting large vessel occlusion. Endovascular therapy was immediately initiated. Left internal carotid angiography indicated occlusion of the distal ICA at the origin of the ophthalmic artery. Injection of contrast medium at a site just proximal to the ICA occlusion depicted the cavernous sinus and inferior petrosal sinus. We withdrew the aspiration catheter to the petrous segment of the ICA and injected contrast medium again. This time, however, neither the cavernous sinus nor the inferior petrosal sinus was visualized. We deployed a stent retriever at the occlusion site and successfully removed the thrombus. The final angiography showed complete recanalization of the affected arterial segment with no sign of a carotid cavernous fistula. The patient was finally discharged on day 73 after endovascular therapy with a cerebral infarction in the territory of the left MCA.

Conclusion: In the present case, angiographic visualization of the cavernous sinus varied depending on the site of contrast medium injection. It appears that the high pressure of the contrast medium generated in the stump of the ICA opened up microvascular shunts between the normal capillaries of the ICA and the cavernous sinus, leading to visualization of the cavernous sinus. Therefore, it is important to be aware that injection of contrast medium into the blind alley of the ICA near the cavernous sinus could result in early visualization of the cavernous sinus.

Objective: During the perioperative period of carotid artery stenting (CAS), severe aortic stenosis (AS) is associated with a risk of serious complications, such as cardiac arrest. There is no consensus regarding the order of treatment for patients with severe AS concomitant with proximal carotid artery stenosis. We herein report a case in which CAS following transcatheter aortic valve implantation for severe AS was safely performed in an older high-risk patient.

Case Presentation: An 84-year-old woman presented with severe aortic stenosis that required treatment. Magnetic resonance angiography revealed severe left proximal internal carotid stenosis. Cerebral blood flow measurements revealed a normal cerebral perfusion. An uneventful transcatheter aortic valve implantation for severe aortic stenosis was followed by carotid stenting at a 2-month interval.

Conclusion: Staged treatment may be a safe and effective strategy in high-risk patients with concomitant severe AS and carotid stenosis. In cases with a normal cerebral blood flow, CAS following transcatheter aortic valve implantation can be a reasonable option, especially in older patients with multiple comorbidities.

Objective: We report a case in which coil embolization was performed for an angiographically occult ruptured anterior communicating artery aneurysm (Acom AN).

Case Presentation: A 91-year-old man was admitted to our hospital because of sudden deterioration of consciousness. Computed tomography (CT) revealed a diffuse subarachnoid hemorrhage in the basal cisterns, and CT angiography identified a 5-mm Acom AN. The next day, a catheter angiogram slightly visualized the neck portion of the Acom AN, despite no apparent visualization of the aneurysmal sac. We suspected intraluminal thrombosis of ruptured Acom AN, and intraaneurysmal coil embolization was performed to prevent re-rupture. By referring to the size and projection of the aneurysmal sac on CT angiography, a microcatheter was guided into the neck portion, and 3 platinum coils were successfully placed within the aneurysm without any complications. Eight days after coil embolization, recanalization of the aneurysm was suspected on magnetic resonance imaging (MRI). Another MRI obtained 17 days after coil embolization revealed gradual recanalization of the aneurysm, which was confirmed on catheter angiogram obtained 22 days after coil embolization. Additional intraaneurysmal coil embolization resulted in complete occlusion. Subsequently, the patient had an uneventful course without rebleeding and was transferred to a rehabilitation center.

Conclusion: We performed intraaneurysmal coil embolization for an angiographically occult ruptured Acom AN by referencing the neck position, aneurysm projection, and aneurysm size on CT angiography. Thus, angiographically occult aneurysms can be treated with endovascular coil embolization despite the need for close follow-up studies to detect recanalization.

Objective: Hematoma expansion in acute epidural hematomas occurred in 11.2%–32% of patients treated conservatively at initial presentation and required craniotomy. Middle meningeal artery (MMA) embolization has been reported to be effective in preventing hematoma expansion. We report a case of an asymptomatic acute epidural hematoma in which CTA was used to identify the source of bleeding. Embolization of the MMA was performed to prevent hematoma expansion.

Case Presentation: A 30-year-old male patient was admitted to the emergency department following a collision with a car while riding his motorcycle. The patient exhibited clear consciousness and no neurological deficits. A head CT scan revealed a right parietal and temporal bone fracture, and an acute epidural hematoma directly below the fracture site. The hematoma was small, and the patient was treated conservatively. Three hours later, a follow-up head CT scan revealed an enlarged hematoma. This hematoma was found near the transverse sinus. To identify the source of the bleeding, a CTA was performed, which revealed extravasation into the hematoma from an area distant from the transverse sinus. We performed embolization of the MMA. The postoperative course was good with no postoperative hematoma expansion.

Conclusion: CTA for acute epidural hematoma without neurological symptoms is a useful diagnostic tool that can identify patients at high risk for hematoma expansion. If the findings indicate the need for intervention, MMA embolization is a treatment option that may reduce the risk of hematoma expansion and craniotomy.

Objective: Loeys-Dietz syndrome (LDS) is an autosomal dominant connective tissue disorder characterized by mutations in the genes encoding transforming growth factor β (TGF-β). LDS is often associated with arterial tortuosity, aortic aneurysm, hypertelorism, and bifid uvula. Patients with LDS are at increased risk for vascular events due to aortic or cerebral aneurysms. We present the 1st reported instance of a carotid-cavernous fistula (CCF) in a patient with LDS.

Case Presentation: A 50-year-old male with LDS due to a pathogenic TGFBR2 variant presented with a 9-month history of bilateral tinnitus, right-sided exophthalmos, and conjunctival chemosis. Imaging revealed a direct Barrow type A CCF between the ventral wall of the internal carotid artery and the right cavernous sinus. The patient underwent transarterial embolization of the CCF using coils and 1 vial of ethylene vinyl alcohol copolymer. Postoperatively, the patient showed marked clinical improvement, with the resolution of pulsatile tinnitus and a gradual reduction of right-sided exophthalmos.

Conclusion: This case illustrates the successful endovascular management of a direct carotid-cavernous fistula in a patient with LDS. Careful pre-interventional imaging to rule out aortic aneurysm and meticulous catheter handling are necessary to achieve successful embolization.

Objective: Dural arteriovenous fistulas (DAVFs) in the superior orbital fissure (SOF) are extremely rare. We report a case of DAVF in the SOF and discuss the characteristics of angioarchitecture and the treatment strategies.

Case Presentation: A 72-year-old woman presented with chemosis, exophthalmos. Digital subtraction angiography revealed a right SOF DAVF mainly supplied from the accessory meningeal artery and the ophthalmic artery, which drained into the facial vein (FV) through the superior ophthalmic vein (SOV) without drainage into the cavernous sinus. A microcatheter was introduced into the shunt pouch via the FV and SOV, and coil embolization of the shunt pouch and SOV was performed, resulting in complete occlusion. However, 1 month later, DAVF recurred, with increased intraocular pressure and decreased vision. A semi-emergent transarterial glue embolization from the accessory meningeal artery was performed and complete occlusion was obtained.

Conclusion: SOF DAVFs often lack cavernous sinus drainage, and transvenous embolization via the FV is recommended if FV drainage is present, but transarterial embolization may be the next treatment of choice if transvenous embolization is unsuccessful.

Objective: Submucosal esophageal hematoma (SEH) is a rare complication of neuroendovascular therapy, and there are insufficient data on the management of antithrombotic therapy in cases of SEH. We report a case of SEH following flow diverter stenting for an unruptured cerebral aneurysm, successfully managed with conservative treatment, including short-term interruption of antiplatelet therapy.

Case Presentation: An 80-year-old woman on clopidogrel and aspirin underwent Pipeline flow diversion with adjunctive coil embolization for an unruptured right internal carotid-posterior communicating artery aneurysm under general anesthesia without complications. Postoperatively, the patient developed chest pain, and CT revealed wall thickening from the middle to lower esophagus, leading to a diagnosis of SEH. SEH in this case was likely caused by a combination of antiplatelet therapy, anticoagulants, nasogastric tube insertion, and mechanical stimulation from intubation and extubation during the operation. The patient was managed conservatively with fasting and discontinuation of antiplatelet therapy. After CT confirmed hemostasis, antiplatelet therapy was resumed with intravenous ozagrel sodium on postoperative day 3, switching to oral prasugrel on day 7. Upper gastrointestinal endoscopy (UGE) on day 8 showed the submucosal hematoma replaced by ulcers and fistula formation. UGE on day 15 showed improvement, and CT on day 23 confirmed hematoma resolution. The patient was discharged on day 24 without symptoms or complications.

Conclusion: In addition to previously reported cases, the presented case suggests that conservative management with temporary antiplatelet interruption and early resumption after hemostasis can lead to favorable outcomes in SEH cases associated with neuroendovascular therapy requiring antiplatelet therapy.

Objective: Cardiologists use the distal radial artery (dRA) approach in daily clinical practice. This method is gradually being applied in neuroendovascular treatment. However, limited studies have been reported concerning tumor embolization using small-bore guidance via dRA.

Case Presentation: Five consecutive tumoral cases underwent endovascular embolization via the dRA approach. The right dRA was punctured, with manual confirmation of pulsation or under the guidance of ultrasonography, using a 22-G plastic cannulation needle. After the insertion of a 0.021-inch guidewire, a dilator of a 4-Fr sheath enlarged the puncture site. The 22-G plastic cannulation needle was replaced with an 18-G cannulation needle, and a 0.035 guidewire was inserted to introduce a small-bore guide. A TEMPO4 (Cordis, Miami Lakes, FL, USA; outer diameter: 1.35 mm) or a 3.6-Fr JB2 (Gadelius Medical, Tokyo, Japan; outer diameter: 1.2 mm) was used in 4 cases to convey embolization materials, whereas a 4-Fr, 16-cm sheath (Terumo, Tokyo, Japan; outer diameter: 2 mm) combined with a 4-Fr SY3 (Gadelius Medical; outer diameter: 1.4 mm) was used in 1 case. Trisacryl gelatin microspheres or n-butyl-2-cyanoacrylate were used as embolization materials. Hemostasis was achieved with PreludeSYNC DISTAL (Merit Medical, South Jordan, UT, USA), and the median time ± standard deviation of hemostasis was 2.00 ± 0.77 h. No complications occurred after embolization.

Conclusion: Tumor embolization using small-bore guide via the dRA approach was completed without any complications.

Objective: Fenestrated basilar artery aneurysms (fBA-ANs) typically arise at the proximal bifurcation of the fenestration limb. It is reported that endovascular treatment with conventional coil embolization or balloon-assisted embolization techniques is often challenging and associated with a high complication rate, especially for wide-neck fBA-ANs. We present a case of fBA-AN successfully treated with stent-assisted coil (SAC) embolization using a novel one-and-a-half-lap approach with an open-cell stent, ensuring reliable neck coverage while preserving parent artery patency.

Case Presentation: A 33-year-old man with a history of an unruptured fBA-AN, previously treated with coil embolization via the double-catheter technique 6 years ago, presented with coil compaction and aneurysm recurrence. DSA revealed an fBA-AN measuring 8.7 mm in diameter, requiring retreatment. Under general anesthesia, SAC was performed using a one-and-a-half-lap approach. A Neuroform Atlas stent (Stryker Neurovascular, Fremont, CA, USA) was deployed via a 2.4 Fr microcatheter, positioned in a clockwise direction from the left loop fenestration to the right loop across the aneurysm neck, followed by coil embolization. Postoperatively, the patient remained free of ischemic complications, and follow-up imaging showed no recurrence of the fBA-AN.

Conclusion: This case demonstrates the efficacy of SAC with a one-and-a-half-lap approach using an open-cell stent for the treatment of complex fBA-ANs. This technique provides a viable treatment option for wide-neck fBA-ANs, ensuring durable aneurysm occlusion while maintaining parent artery patency.

Objective: The global increase in methamphetamine abuse has increased the incidence of methamphetamine-associated cardiomyopathy (MACM), which is often complicated by left ventricular thrombosis and acute ischemic stroke. Here, we report a case of left internal carotid artery occlusion during acute heart failure treatment in a patient with MACM that led to mechanical thrombectomy.

Case Presentation: A 54-year-old man with a history of approximately 30 years of methamphetamine abuse presented with dilated cardiomyopathy complicated by a left ventricular thrombus. On the night of admission for acute heart failure management, he experienced a sudden onset of consciousness disturbance, severe aphasia, and right hemiparesis. MRI revealed mild hyperintensities in the left cerebral hemisphere cortex and lenticular nucleus on diffusion-weighted imaging, with no abnormal signals on fluid-attenuated inversion recovery. He underwent mechanical thrombectomy, achieving complete reperfusion within 150 min; however, he experienced ipsilateral cerebral hyperemia that persisted for 30 days postoperatively. By the 90th postoperative day, moderate aphasia and mild paralysis of the right upper limb remained, with a modified Rankin Scale score of 3.

Conclusion: Left ventricular thrombosis is relatively common in patients with MACM, necessitating careful consideration of the risk of cardioembolic stroke.

Objective: Presurgical identification of the artery of Adamkiewicz (AKA) is crucial in thoracic and lumbar spinal lesions. Although CTA is widely employed to identify AKA, the detection rate varies across reports and is often difficult, especially in patients with spinal dural arteriovenous fistulas (SDAVFs). We report 2 cases where sublingual administration of nitroglycerin (NTG), a vasodilator, before CTA enabled good visualization of the AKA in patients with SDAVF.

Case Presentation: (Case 1) A patient in his 60s presented with progressive gait disturbance, and an MRI revealed a spinal vascular lesion. CTA with sublingual NTG administration revealed an SDAVF supplied by the right seventh intercostal artery and an AKA branching from the left ninth intercostal artery. A chronic descending aortic dissection was identified on CTA, but spinal angiography was not performed. The patient was successfully managed with direct surgical disconnection of the SDAVF, and his symptoms improved. (Case 2) A patient in his 60s presented with progressive bilateral lower-limb numbness, and a thoracic SDAVF was diagnosed using MRI. CTA without NTG administration failed to identify the AKA, but after the administration of NTG, a clear depiction of the AKA branching from the left 10th intercostal artery was obtained. Endovascular shunt occlusion was successfully performed via the right 10th intercostal artery, resulting in significant symptom improvement.

Conclusion: Sublingual NTG administration before CTA may improve AKA expression in patients with SDAVF.

Objective: Direct carotid-cavernous fistula (CCF) is a common neurovascular complication associated with Ehlers–Danlos syndrome (EDS). Nevertheless, reports indicate a significant incidence of treatment-related complications.

Case Presentation: We present a case of right CCF in a 28-year-old female with EDS. Femoral artery and vein punctures were performed under ultrasound guidance. We executed transvenous embolization (TVE) of the draining veins and the shunted fistula using a combination of coils and n-butyl-2-cyanoacrylate (NBCA), facilitated by an assisted transarterial balloon. The CCF resolved without any procedural complications.

Conclusion: Utilizing a combination of coils and NBCA in TVE is seen as a safe and efficient method for addressing CCF in patients with EDS. It enables preserving better visualization of the cavernous sinus and adjacent structures, making this approach particularly effective. By keeping a close watch, monitoring for potential high-risk complications, and strategically placing devices between the arterial and venous sides, the arterial puncture profile is reduced, enabling safer endovascular treatment.

Objective: Treatment of infectious aneurysms is challenging because of the fragility of the vessel walls. Surgical trapping and endovascular parent artery occlusion are the treatments of choice for medically intractable infectious aneurysms. Here, we describe a patient with an infectious aneurysm at the extracranial petrous segment of the internal carotid artery that was secondary to exudative otitis media; it was successfully treated with reconstructive endovascular interventions using a flow redirection endoluminal device (FRED).

Case Presentation: A 57-year-old man was administered antibiotics for exudative otitis media. After 6 months, the patient underwent CT screening, which revealed destruction of the petrous bone and a pseudoaneurysm at the petrous segment of the left internal carotid artery. Catheter angiography, including a balloon occlusion test, revealed a 47-mm wide-necked pseudoaneurysm at the distal cervical segment of the left internal carotid artery with poor collateral blood supply to the left internal carotid artery. We performed reconstructive endovascular treatment using a FRED. A follow-up catheter angiogram after 6 months confirmed a minor neck remnant of the aneurysm.

Conclusion: Flow diversion may be a useful treatment approach for extracranial infectious aneurysms, despite concerns about incomplete obliteration of the aneurysm and the persistent risk of re-rupture before complete obliteration.

Objective: Right aortic arch is a rare congenital anomaly. We report a case of mechanical thrombectomy for acute left medium-vessel occlusion due to a paradoxical embolism in a patient with a right aortic arch.

Case Presentation: An 81-year-old woman presented with severe right-sided hemiparesis and aphasia. The National Institutes of Health Stroke Scale score was 16, MRI demonstrated a diffusion-weighted imaging Alberta Stroke Program Early CT score of 7, and MRA revealed left M2 occlusion. CTA revealed a right aortic arch with mirror image branching. Mechanical thrombectomy was conducted using the usual system, and effective recanalization was achieved with a stent retriever and aspiration catheter after 3 passes. CTA revealed pulmonary embolism and deep vein thrombosis (DVT) in the right deep femoral vein, and transesophageal echocardiography demonstrated a patent foramen ovale. Electrocardiography did not reveal atrial fibrillation, and other examinations did not reveal any other cause; therefore, a paradoxical cerebral embolism was diagnosed. After anticoagulant therapy, no recurrence of infarction, pulmonary embolism, or DVT was observed. Severe right hemiparesis and total aphasia did not improve, and the patient was discharged on day 37 after admission with a modified Rankin Scale score of 5.

Conclusion: Access to the left common carotid artery in right aortic arch cases can be anatomically challenging. Preoperative imaging evaluation of the access route is crucial for quick and safe mechanical thrombectomy.

Objective: To assess the efficacy of mechanical thrombectomy (MT) for cerebral venous sinus thrombosis associated with Ewing sarcoma invasion into the venous sinus.

Case Presentation: A 48-year-old woman presented to our hospital with left hemifacial paralysis. The patient had undergone surgical treatment for left subclavian Ewing sarcoma 24 years ago. Furthermore, the patient had undergone tumor resection for very late metastasis in the left occipital bone and mastoid air cells 3 years prior to her admission. As the Ewing sarcoma had extended to the left transverse sinus, the sinus was resected during craniotomy. The tumor remained in the mastoid air cells, and radiotherapy was administered. On admission to our hospital, FLAIR revealed hyper-intensities in the straight sinus and the superior sagittal sinus. Magnetic resonance venography revealed no signal in the posterior part of the superior sagittal sinus and the bilateral transverse sinuses. The patient was diagnosed with cerebral venous sinus thrombosis, and anticoagulation therapy was administered. However, the swelling and pain on the left side of the face worsened, and intraocular pressure (IOP) increased. Therefore, an MT was performed. After endovascular treatment, the patient’s facial swelling and pain were reduced, and IOP returned to normal. Pathological examination of the captured thrombus revealed tumor cells, suggesting venous sinus invasion of Ewing sarcoma.

Conclusion: Although it was a palliative treatment, MT was effective in confirming the diagnosis of tumor invasion into the venous sinus and improving the patient’s quality of life.

Objective: A hyperplastic anterior choroidal artery (AchA) is a rare anomalous vessel that perfuses the posteromedial aspects of the cerebrum in place of the posterior cerebral artery. We describe 3 cases of hyperplastic AchA found among 61 patients with AchA aneurysms who underwent surgical or endovascular treatment at our institution.

Case Presentation: All 3 cases were diagnosed as hyperplastic AchA type 2 according to the Takahashi classification, indicating an anomalous branching temporal artery perfusing the medial temporal lobe. We performed coil embolization for 2 cases and surgical clipping for the third. One embolization case experienced recurrence after 3 years and underwent clipping. All procedures were conducted without complications.

Conclusion: Hyperplastic AchA can be encountered during aneurysm treatment. These cases emphasize the importance of evaluating the vascular anatomy to determine the optimal treatment strategy.

Objective: Herein, we present a novel flow reversal technique using dual-balloon inflation that can provide enhanced catheter stability and reliable embolic protection for percutaneous antegrade stenting in a patient with right common carotid artery (CCA) stenosis.

Case Presentation: A 75-year-old female patient with post-radiation right CCA stenosis initially underwent stenting using distal filter protection, which resulted in transient left upper limb paralysis caused by embolic infarction. After restenosis at 6 months, retreatment was performed using dual-balloon occlusion with the 9-F balloon guiding catheter in the innominate artery and the 8-F balloon guiding catheter in the right subclavian artery. Intraoperative ultrasonography confirmed a successful flow reversal, and debris was captured from the aspirated blood. The patient was discharged without neurological deficits, and postoperative imaging showed no new ischemic lesions.

Conclusion: The novel flow reversal technique using dual-balloon inflation can be effective and safe for treating right CCA stenosis by achieving both reliable embolic protection and improved catheter stability.

Objective: Not many reports of subclavian artery occlusion complicated by vertebrobasilar junction aneurysm have been published, and no cases have been treated using a distal radial approach. Our case report highlights the effectiveness of this approach in comparison to previous findings.

Case Presentation: An 82-year-old woman was referred to our hospital because of an enlarged vertebrobasilar junction aneurysm. The DSA and CTA results revealed a left subclavian artery occlusion, meandering of the descending aorta, and an aneurysm of the descending aorta. We performed coil embolization using the right radial and left distal radial artery approaches. Considering that the left subclavian artery occlusion was related to the aneurysm enlargement, we decided to perform left subclavian artery stenting. Left subclavian artery stenting was performed 1 month after coil embolization using the same approach. The patient was discharged on postoperative day 8 without complications.

Conclusion: Vertebrobasilar junction aneurysm and subclavian artery occlusion were treated via a safe and minimally invasive approach through the right radial and left distal radial artery approaches.