中原 一郎

BACKGROUND: This study evaluated the safety and efficacy of a treatment strategy for Posterior communicating artery (PCOM) aneurysms using first-line Woven EndoBridge (WEB), supplemented by Flow diverter (FD) in selected cases. METHODS: This retrospective study included patients who underwent endovascular treatment for PCOM aneurysms between January 2021 and March 2025. Aneurysms were categorized as fetal or non-fetal. A first-line WEB strategy was adopted when morphology was suitable. Radiological and clinical outcomes were assessed. RESULTS: Forty-six PCOM aneurysms met the criteria: 14 fetal-type and 32 non-fetal-type. All previously untreated fetal-type aneurysms were treated with WEB (n = 9). In the non-fetal group, the initial treatments included WEB (n = 14), FD (n = 10), and coiling (n = 4). All recurrent fetal-type aneurysms were retreated with FD (n = 5), whereas non-fetal recurrences were managed with FD (n = 3) or coiling (n = 1), depending on prior treatment. At a median follow-up of 21 months, complete occlusion was achieved in 66.7% of fetal-type and 59.4% of non-fetal-type aneurysms (P = 0.739), and adequate occlusion was achieved in 75.0% and 90.6%, respectively (P = 0.321). Retreatment was required in two cases (4.3%): one in the fetal group (7.1%) and one in the non-fetal group (3.1%) (p = 0.512). No modified Rankin Scale worsening or major complications occurred. No significant differences in treatment efficacy were observed among modalities selected under the WEB first-line strategy. CONCLUSION: A first-line WEB strategy is safe and effective for PCOM aneurysms, including fetal-type variants, with outcomes for fetal-type aneurysms comparable to non-fetal-type aneurysms.

Older age and Fisher group scores predict poor outcomes in patients with aneurysmal subarachnoid hemorrhage (aSAH). However, among aging societies, treatment indications and decisions in older patients with severe-grade aSAH (World Federation of Neurosurgical Societies [WFNS] grade IV or V) remain poorly understood. Therefore, we aimed to identify the risk factors associated with poor outcomes in non-older and older patients with severe-grade aSAH. We analyzed a database of patients with aSAH treated between April 2007 and December 2019 in Japan and divided them into either the non-older (< 75 years) or older group (age ≥ 75 years) to identify factors associated with poor outcomes (modified Rankin Scale score [mRS] 3-6) at discharge. The data analyzed included patient demographics, comorbidities, aneurysm characteristics, Fisher group, WFNS grade, treatment method, and mRS score at discharge. Among the 5,095 patients, 1,303 (986 non-older and 317 older) were classified as having severe-grade aSAH. In non-older patients, chronological age (odds ratio [OR], 1.04; 95% confidence interval [CI], 1.03-1.05) and Fisher groups 3 and 4 were associated with poor outcomes as compared with Fisher group 1 + 2 (OR, 2.98; 95% CI, 1.59-5.58 and OR, 5.49; 95% CI, 2.86-10.54, respectively). However, chronological age and Fisher groups 3 and 4 were not associated with poor outcomes in older patients with severe-grade aSAH. This study suggests that outcomes in older patients with severe-grade aSAH cannot be predicted in the same manner as in non-older patients. Further research on potential prognostic factors, such as biological age, is warranted. Clinical trial number Not applicable.

BACKGROUND: This study aimed to determine the efficacy of flow diverters (FDs) for small/medium (≤10 mm) aneurysms and analyzed the factors that prevent aneurysm occlusion. METHODS: This retrospective single-center study evaluated the angiographic and clinical data of consecutive patients between June 2020 and February 2023. RESULTS: Overall, 121 small/medium aneurysms were observed in 106 patients treated with FDs. The median dome diameter was 6.1 (5.1-7.2) mm. Symptomatic thromboembolic complications were observed in four (3.7 %) patients, and none showed a major ischemic stroke. Intracranial hemorrhage was detected using postprocedural computed tomography in one (0.9 %) patient with asymptomatic subarachnoid hemorrhage. The rate of permanent neurological deficits was 1.8 %, and the mortality rate was 0 %. No delayed ischemic or hemorrhagic complications were observed during follow-up. Angiographic follow-up revealed complete and adequate occlusion (O'Kelly-Marotta grades C and D) rates of 77.5 % and 90.8 %, respectively. On multivariate analysis, incomplete occlusion was only associated with the presence of a branch vessel from the aneurysm dome (P < 0.01). In aneurysms with incorporated branch vessels, univariate analysis revealed that coil usage was a predictor of complete occlusion (P = 0.03). Moreover, even without using coils, effective occlusion was achieved when the branch vessel diameter was small (P = 0.03). CONCLUSIONS: FDs are an effective and safe treatment option for small/medium aneurysms. The presence of incorporated branch vessels can predict incomplete occlusion. Even in aneurysms with incorporated branch vessels, FD can obtain therapeutic effects by adding coil embolization or treating with only FD if the branch vessel diameter is small.

OBJECTIVE: Aneurysmal subarachnoid hemorrhage (SAH) is associated with high morbidity and mortality rates. In particular, functional outcomes of SAH caused by large or giant (≥ 10 mm) ruptured intracranial aneurysms are worsened by high procedure-related complication rates. However, studies describing the risk factors for poor functional outcomes specific to ruptured large/giant aneurysms are sparse. In addition, high recurrence and rebleeding rates following treatment of such aneurysms remain a concern. This study aimed to clarify the specific risk factors for poor short-term outcomes and long-term durability of SAH due to ruptured large/giant intracranial aneurysms using a multicenter observational database in Japan. METHODS: Data were obtained from 8 institutions participating in a multicenter repository of aneurysmal SAH in Japan. Among 5095 consecutive registered patients with SAH patients, 416 patients with SAH caused by ruptured large/giant (≥ 10 mm) saccular intracranial aneurysms were included. The authors investigated the risk factors for poor functional outcomes in patients with such aneurysms using multivariable analyses and subsequently investigated the interaction between these risk factors. The association between the treatment modality (direct surgery or endovascular therapy) and functional outcomes were finally analyzed using a propensity score-based method. The long-term durability of the treated aneurysms was evaluated by analyzing rebleeding. RESULTS: Poor functional outcomes (modified Rankin Scale score ≥ 3) at discharge were observed in 251 (60.3%) patients. Increasing aneurysm size was significantly associated with poor functional outcomes (OR 1.13, 95% CI 1.04-1.22; p = 0.003) by a multivariable logistic regression analysis, and such negative effects were more prominent in younger patients, those with a good initial neurological grade, and those treated with direct surgery by interaction analyses. Propensity score-based analysis revealed that patients treated with endovascular therapy had a higher chance of better functional outcomes (OR 1.56, 95% CI 1.41-1.71; p = 0.03). Rebleeding 1 year after treatment was more frequent in the endovascular therapy (4.8%) than in the direct surgery (0.0%) group by survival analysis (p = 0.008, log-rank test). CONCLUSIONS: Increasing aneurysm size was identified as a risk factor for poor functional outcomes after SAH due to large/giant aneurysms and was affected by the interaction with other conventional risk factors. Endovascular therapy was more likely to be associated with better short-term outcomes; however, a higher delayed rebleeding rate after 1 year was a concern.

BACKGROUND: This report presents a rare case of trigeminal neuralgia (TN) caused by a radicular arteriovenous fistula (AVF). CASE DESCRIPTION: A 58-year-old woman presented with severe pain in the right lower jaw, typical of TN. Magnetic resonance imaging showed a vascular signal near the trigeminal nerve. Direct surgery revealed tortuous vessels on the dorsal surface of the nerve, with no offending vessels identified at the root entry zone. Digital subtraction angiography (DSA) confirmed a radicular AVF fed by the trigeminocerebellar artery, with venous drainage into the superior petrosal sinus through the petrosal vein. Endovascular embolization with n-butyl cyanoacrylate resulted in complete obliteration of the fistula and symptom resolution. Although a small pontine infarction occurred, no long-term deficits were observed. Follow-up DSA confirmed no recurrence. CONCLUSION: To the best of our knowledge, this represents the first documented case of a trigeminal radicular AVF, highlighting the importance of recognizing vascular anomalies and efficacy of endovascular treatment in managing TN.

OBJECTIVE: The Woven EndoBridge (WEB; MicroVention TERUMO, Tustin, CA, USA) is an intrasaccular flow disruptor developed for the treatment of wide-neck bifurcation aneurysms (WNBA). While its safety and satisfactory mid- to long-term treatment outcomes have been documented, there have also been reports of complications such as WEB protrusion and migration. We encountered 3 cases in which the WEB protruded or migrated to the parent vessel after deployment, necessitating retrieval. In this report, we address the technical tips for retrieval techniques and factors associated with these complications, including a literature review. CASE PRESENTATION: Of the 120 cases of our experience with WEB treatment for cerebral aneurysms for the period since January 2021, 3 required WEB retrievals. In 2 cases, significant WEB migration toward the parent vessel occurred while maneuvering the delivery microcatheter because of sticky detachment. In the remaining case, after detachment of the WEB, tilting occurred, leading to a strong protrusion into one of the branches, which prevented guiding the microcatheter for bailout stenting. In all cases, the proximal marker of the WEB was captured using an Amplatz Goose Neck Microsnare (Medtronic, Minneapolis, MN, USA) pulled back into the VIA catheter (the delivery catheter for the WEB; MicroVention TERUMO), and further into an intermediate catheter positioned as close to the aneurysm as possible, enabling uneventful retrieval. CONCLUSION: None of the cases damaged the aneurysm or proximal parent vessel wall, and additional aneurysm occlusion treatment was performed. However, WEB protrusions and migration are rare. When retrieval is required, it is crucial to act swiftly owing to the risk of distal thrombosis from the lumen inside of the WEB. Therefore, recognizing Goose Neck Microsnare as a retrieval technique is valuable.

BACKGROUND: Aneurysmal subarachnoid hemorrhage caused by cerebral aneurysm rupture has a poor prognosis, with mortality exceeding 30% despite treatment advancements. Surgical neck clipping remains the standard for preventing rupture, but intraoperative rupture rates vary significantly (3-50%) and are influenced by vascular complexity and technical challenges. Thinning of the vascular wall near the aneurysm neck, particularly with microaneurysm formation, has emerged as a significant risk factor, yet these changes often go undetected in preoperative imaging. OBJECTIVE: This study aimed to evaluate the utility of computational fluid dynamics (CFD) analysis for predicting microaneurysm formation in the parent artery adjacent to unruptured cerebral aneurysms, using the parent artery radiation sign (PARS) as a predictive marker. METHODS: We conducted a single-center, retrospective observational study of 89 patients with unruptured middle cerebral artery (MCA) aneurysms treated with neck clipping from May 2020 to April 2022. Based on preoperative three-dimensional computed tomography angiography (3D-CTA), CFD analysis identified PARS through specific hemodynamic indicators. Intraoperative findings were analyzed and compared between PARS-positive and PARS-negative groups. The sensitivity and specificity of PARS for predicting microaneurysm formation were investigated. RESULTS: Of the 87 aneurysms analyzed, 25 (28.7%) were PARS-positive, and 62 (71.3%) were PARS-negative. Microaneurysms were identified intraoperatively in nine cases, eight of which were in the PARS-positive group. The sensitivity and specificity of PARS for detecting microaneurysms were 89 and 78%, respectively. The positive likelihood ratio was 4.1, while the negative likelihood ratio was 0.142. CONCLUSION: CFD analysis using PARS offers a reliable method for predicting microaneurysm formation in the parent artery, potentially guiding surgical planning and reducing intraoperative rupture risk. While promising, these findings are limited by the retrospective, single-center design, highlighting the need for further research in larger, multicenter cohorts. Incorporating CFD analysis into preoperative assessment could significantly enhance the safety and outcomes of neck clipping procedures for unruptured cerebral aneurysms.

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.

PURPOSE: This study aimed to classify medullary bridging vein-draining dural arteriovenous fistulas (MBV-DAVFs) located around the foramen magnum (FM) according to their location and characterize their angioarchitecture and treatment outcomes. METHODS: Patients with MBV-DAVFs diagnosed between January 2013 and October 2022 were included. MBV-DAVFs were classified into four groups. Jugular vein-bridging vein (JV-BV) DAVF: located in proximity to jugular fossa, Anterior condylar vein (ACV)-BV DAVF: proximity to anterior condylar canal, Marginal sinus (MS)-BV DAVF: lateral surface of FM and Suboccipital cavernous sinus (SCS)-BV DAVF: proximity to dural penetration of vertebral artery. RESULTS: Twenty patients were included, three JV-BV, four ACV-BV, three MS-BV and ten SCS-BV DAVFs, respectively. All groups showed male predominance. There were significant differences in main feeders between JV (jugular branch of ascending pharyngeal artery) and SCS group (C1 dural branch). Pial feeders from anterior spinal artery (ASA) or lateral spinal artery (LSA) were visualized in four SCS and one MS group. Drainage pattern did not differ between groups. Transarterial embolization (TAE) was performed in three, two, one and two cases and complete obliteration was obtained in 100%, 50%, 100% and 0% in JV, ACS, MS and SCS group, respectively. Successful interventions without major complications were finally obtained in 100%, 75%, 100%, and 40% in JV, ACS, MS and SCS group, respectively. CONCLUSION: JV-BV DAVFs were successfully treated using TAE alone. SCS-BV DAVFs were mainly fed by small C1 dural branches of vertebral artery often with pial feeders from ASA or LSA, and difficultly treated by TAE alone.

It is impossible to predict underlying anomalies in acute large vessel occlusion and it could be a problem when performing mechanical thrombectomy (MT). We report a case of MT for occlusion of the fenestrated middle cerebral artery (MCA) M1 segment. A 49-year-old woman presented to our hospital with dysarthria and left hemiparesis. Acute ischemic stroke due to right occluded MCA was diagnosed. During performing emergent MT, a part of the M1 segment was revealed to be slit-shaped by digital subtraction angiography, suggesting a fenestrated MCA. The aspiration catheter could not be advanced through the narrow limb of the fenestration, and the distal thrombus was retrieved using a stent retriever, additionally. Postoperatively, the patient's symptoms improved without complications. When occlusion of the fenestrated MCA is suspected, it is necessary to consider converting the strategy from an aspiration catheter alone to the combined use of a stent retriever.

PURPOSE: Prasugrel is not approved for patients treated with flow diverters, which have a high metal coverage ratio. However, robust antiplatelet therapy with prasugrel may prevent thromboembolic complications. We administered prasugrel and aspirin to all patients treated with flow diverters and reported the safety of the antiplatelet therapy regimen. METHODS: This retrospective, single-center study evaluated the angiographic and clinical data of consecutive patients treated with flow diverters for cerebral unruptured aneurysms between June 2020 and May 2022. All patients received dual antiplatelet therapy, including prasugrel and aspirin. The administration of prasugrel ended 3 or 6 months after the procedure, whereas aspirin use continued for at least 12 months. Periprocedural complications (< 30 days post-procedure) and delayed complications (> 30 days post-procedure) were recorded. RESULTS: During the study period, 120 unruptured aneurysms were treated with flow diverters in 110 patients. All patients, except one, survived longer than 12 months after the procedure. The rate of thromboembolic complications was 6.4%, and more than half of the patients had transient symptoms; one (0.9%) had a major ischemic stroke. One patient (0.9%) each had an asymptomatic, small subarachnoid hemorrhage and significant hemorrhagic complications with melena. The rate of permanent neurological deficits was 1.8%, and the mortality rate was 0.9%. CONCLUSIONS: Dual antiplatelet therapy comprising routine use of prasugrel and aspirin for flow diverter-implanted patients possibly contributed to a low rate of thromboembolic complications and low risk of hemorrhagic complications.

OBJECTIVE: LEONIS Mova (SB-KAWASUMI LABORATORIES, Kanagawa, Japan, hereinafter called LEONIS Mova) is a steerable microcatheter (MC) that enables angle adjustment of the catheter tip using a hand-operated dial. LEONIS Mova may be useful for flow diverter placement when access to the distal parent artery with a conventional MC and microguidewire (MGW) is considered difficult or impossible. Here, we report three such cases encountered during flow diverter placement in large and giant internal carotid artery aneurysms. CASE PRESENTATION: In Case 1, a strong S-shaped curve was observed in the proximal parent artery of a giant cerebral aneurysm, and the luminal structure of the parent artery was lost within the aneurysm. It was anticipated that the distal side of the parent artery would be difficult to access with conventional MC and MGW. By adjusting the tip of the LEONIS Mova toward the aneurysm outlet beyond the S-shaped curve, it was possible to induce the MGW to secure the distal parent artery easily. In Case 2, the inflow and outflow axes of the parent artery were completely misaligned at the site of the aneurysm, and stenosis was present in the distal parent artery. Firmly bending the catheter tip increased accommodation for the catheter, enabling the induction of an MGW to access the distal parent artery without kicking back. In Case 3, the lesion extended from the cavernous portion to the petrosal portion; however, by adjusting the tip of the LEONIS Mova toward the aneurysm outlet, it was possible to induce the MGW to secure the distal parent artery easily. In each case, the LEONIS Mova enabled more secure and prompt access to the parent artery than anticipated and facilitated flow diverter placement. CONCLUSION: Encountering difficult-to-access lesions is one reason endovascular treatment may be unsuccessful. The LEONIS Mova is an excellent device that can overcome this obstacle, and its utility in certain applications should be recognized.

BACKGROUND AND OBJECTIVES: The differences in clinical outcomes between endovascular coiling (EC) and surgical clipping (SC) in patients with poor-grade aneurysmal subarachnoid hemorrhage (aSAH) are controversial. Therefore, this study aimed to evaluate whether EC is superior to SC and identify risk factors in patients with poor-grade aSAH. METHODS: We used data from the "Predict for Outcome Study of aneurysmal SubArachnoid Hemorrhage." World Federation of Neurological Societies (WFNS) grade III-V aSAH was defined as poor-grade aSAH, and unfavorable clinical outcomes (modified Rankin Scale scores 3-6) were compared between SC and EC after propensity score matching (PSM). In-hospital mortality was similarly evaluated. Predictors of unfavorable clinical outcomes were identified using multivariable analysis. RESULTS: Ultimately, 1326 (SC: 847, EC: 479) and 632 (SC: 316, EC: 316) patients with poor-grade aSAH were included before and after PSM, respectively. Unfavorable clinical outcomes at discharge were significantly different between SC and EC before (72.0% vs 66.2%, P = .026) and after PSM (70.6% vs 63.3%, P = .025). In-hospital mortality was significantly different between groups before PSM (10.5% vs 16.1%, P = .003) but not after PSM (10.4% vs 12.7%, P = .384). Predictors of unfavorable clinical outcomes in both SC and EC were WFNS grade V, older than 70 years, and Fisher computed tomography (CT) grade 4. Predictors of unfavorable clinical outcomes only in SC were WFNS grade IV (odds ratio: 2.46, 95% CI: 1.22-4.97, P = .012) and Fisher CT grade 3 (4.90, 1.42-16.9, P = .012). Predictors of unfavorable clinical outcome only in EC were ages of 50s (3.35, 1.37-8.20, P = .008) and 60s (3.28, 1.43-7.52, P = .005). CONCLUSION: EC resulted in significantly more favorable clinical outcomes than SC in patients with poor-grade aSAH, without clear differences in in-hospital mortality. The benefit of EC over SC might be particularly remarkable in patients with WFNS grade IV and Fisher CT grade 3.

Ischemia-induced postoperative scalp necrosis in the superficial temporal artery (STA) region is known to occur after STA-middle cerebral artery anastomoses. However, no reports have evaluated the risk of postoperative scalp necrosis in the occipital artery (OA) region. This study examined the surgical procedures that pose a risk for postoperative scalp necrosis in the OA region following posterior cranial fossa surgery. Patients who underwent initial posterior fossa craniotomy at our institution from 2015 to 2022 were included. Clinical information was collected using medical records. Regarding surgical procedures, we evaluated the incision design and whether a supramuscular scalp flap was prepared. The supramuscular scalp flap was defined as a scalp flap dissected from the sternocleidomastoid and/or splenius capitis muscles. A total of 392 patients were included. Postoperative scalp necrosis occurred in 19 patients (4.8%). There were 296 patients with supramuscular scalp flaps, and supramuscular scalp flaps prepared in all 19 patients with postoperative necrosis. Comparing incision designs among patients with supramuscular scalp flap, a hockey stick-shaped scalp incision caused postoperative necrosis in 14 of 73 patients (19.1%), and the odds of postoperative scalp necrosis were higher with the hockey stick shape than with the retro-auricular C shape (adjusted odds ratio: 12.2, 95% confidence interval: 3.86-38.3, p = 0.00002). In all the cases, ischemia was considered to be the cause of postoperative necrosis. The incidence of postoperative necrosis is particularly high when a hockey stick-shaped scalp incision is combined with a supramuscular scalp flap.

BACKGROUND AND PURPOSE: There has been limited literature regarding the bridging veins (BVs) of the medulla oblongata around the foramen magnum (FM). The present study aims to analyze the normal angioarchitecture of the BVs around the FM using slab MIP images of three-dimensional (3D) angiography. METHODS: We collected 3D angiography data of posterior fossa veins and analyzed the BVs around the FM using slab MIP images. We analyzed the course, outlet, and number of BVs around the FM. We also examined the detection rate and mean diameter of each BV. RESULTS: Of 57 patients, 55 patients (96%) had any BV. The median number of BVs was two (range: 0-5). The BVs originate from the perimedullary veins and run anterolaterally to join the anterior condylar vein (ACV), inferior petrosal sinus, sigmoid sinus, or jugular bulb, inferolaterally to join the suboccipital cavernous sinus (SCS), laterally or posterolaterally to join the marginal sinus (MS), and posteriorly to join the MS or occipital sinus. We classified BVs into five subtypes according to the draining location: ACV, jugular foramen (JF), MS, SCS, and cerebellomedullary cistern (CMC). ACV, JF, MS, SCS, and CMC BVs were detected in 11 (19%), 18 (32%), 32 (56%), 20 (35%), and 16 (28%) patients, respectively. The mean diameter of the BVs other than CMC was 0.6 mm, and that of CMC BV was 0.8 mm. CONCLUSION: Using venous data from 3D angiography, we detected FM BVs in most cases, and the BVs were connected in various directions.

OBJECTIVE: This retrospective study aimed to investigate factors associated with inhibition of early aneurysm obliteration after flow diverter (FD) treatment. We also created the early obliteration inhibition (EOI) score for pre-operative evaluation. METHODS: We examined 110 cerebral aneurysms in 104 patients who underwent FD treatment. The following parameters were investigated: age, sex, symptoms, aneurysm location and type, maximum aneurysm diameter, parent vessel diameter, neck diameter, and dome-neck ratio. We also noted aneurysm location relative to the curvature of the parent artery and any branches arising from the aneurysm dome. Procedural factors such as FD diameter and length, number of FDs placed, type of FD, and use of adjunctive coiling were also investigated. Aneurysm obliteration was evaluated using digital subtraction angiography 3 months after the procedure. Adequate obliteration was defined as grade C or D on the O'Kelly-Marotta scale. RESULTS: The following factors inhibited early obliteration: 1) extradural location, 2) saccular aneurysm, 3) aneurysm neck located at the outer convexity of the parent artery, and 4) arterial branch arising from the aneurysm dome. Odds ratios were used to create an EOI score. Receiver operating characteristic curve analysis showed that the optimal cut-off EOI score for adequate obliteration was 1.5 (area under the curve, 0.81; 95% confidence interval, 0.73-0.9; sensitivity, 0.9; specificity, 0.57). CONCLUSION: The EOI score, which is based on factors that inhibit early obliteration, may predict early treatment outcomes of FD placement.

PURPOSE: Optimal size selection is important for successful Woven EndoBridge (WEB) treatment. Conventional recommendations for WEB sizing based on aneurysm width and height sometimes require device exchange. We aimed to design a novel volume-based parameter, the ideal WEB-aneurysm volume (iWAVe) ratio, for optimal WEB sizing. METHODS: Consecutive patients who underwent WEB treatment for wide-neck bifurcation aneurysms between January 2021 and May 2022 were retrospectively reviewed. Aneurysm volume was automatically calculated using software. We measured the aneurysm volume based on the expected position of the device within the aneurysm. The WAVe ratio was defined as the ratio of the aneurysm volume to WEB volume. We dichotomized aneurysms treated with a successful sizing or unsuccessful sizing for WEB (successful group and unsuccessful group, respectively). RESULTS: Thirty-five patients were eligible for study enrollment. Ten patients (28.6%) needed to exchange the WEB on the first attempt and required another WEB on the second attempt resulting in deployment success. Hence, 35 aneurysms were in the successful group and 10 were in the unsuccessful group. The median WAVe ratio was 1.0 (range 0.76-1.31) in the successful group and 1.27 (0.58-1.89) in the unsuccessful group. Using logistic regression, iWAVe ratio was from 0.90-1.16 to secure a >80% probability of success by the 95% lower confidence limit. The sensitivity and specificity of the iWAVe ratio for optimal size selection on the first attempt were 0.60 and 1.00, respectively. CONCLUSION: Decision-making based on aneurysm width and the iWAVe ratio could promote optimal WEB sizing.

OBJECTIVE: Although a qualitative diagnosis of plaque causing carotid stenosis has been attempted with carotid computed tomography angiography (CaCTA), no clear findings have been reported. We examined the correlation between the plaque CT values and plaque images obtained by magnetic resonance imaging to derive a qualitative diagnosis of the plaque using CaCTA. METHODS: Preoperative CaCTA images acquired from patients stented for carotid stenosis were retrospectively analyzed with respect to magnetization-prepared rapid acquisition with gradient echo and time-of-flight magnetic resonance angiography data. Carotid plaques in the stenosed region were quantified in terms of CT density and the plaque/muscle ratio (magnetization-prepared rapid acquisition with gradient echo), and correlations between these 2 features were determined. Plaques were classified as stable or unstable based on the plaque/muscle ratio, with the smallest plaque/muscle ratio observed among plaques positive for intraplaque hemorrhage set as the cutoff value (1.76). RESULTS: A total of 165 patients (179 plaques) were included. Perioperative complications included minor stroke (n = 3), major stroke (n = 1, fatal), and hyperperfusion (n = 2). The correlation between CT density and the plaque/muscle ratio was nonlinear (P = 0.0139) and negative (P < 0.0001). The cutoff point (1.76) corresponded to a CT density of 83 HU, supporting this value as a standard reference for plaque stability. CONCLUSIONS: Computed tomography density exhibits a nonlinear (P = 0.0139) and highly negative correlation (P < 0.0001) with the plaque/muscle ratio. Our results demonstrate that plaque characteristics can be meaningfully diagnosed based on CaCTA image data.

OBJECTIVE: Some aneurysmal subarachnoid hemorrhage (SAH) patients are delayed in their presentation. This can cause a washout of the subarachnoid hematoma and a potential misdiagnosis. As a result, they may suffer rerupture of the aneurysm and preventable deterioration. We investigated the factors that influence delayed SAH presentation. METHODS: Aneurysmal SAH patients treated at 9 stroke centers from 2002 to 2020 were included. Age, gender, pre-SAH modified Rankin scale, World Federation of Neurological Surgeons grade, Fisher group, day of presentation, aneurysm treatment method, past history of cerebral stroke, comorbidity of hypertension and/or diabetes mellitus, and modified Rankin scaleat discharge were assessed retrospectively. We formed 2 groups based on the day of presentation after the onset of SAH: day 0-3 (early) and other (delayed). Logistic regression analyses detected the factors that influenced the day of presentation and outcome for SAH. A P- value <0.05 was considered significant. RESULTS: Delayed presentation comprised 282 cases (6.3%) of 4507 included cases. Logistic regression analyses showed that patients in an urban area, of male gender, low WFNS grade and low Fisher group correlated significantly with a delayed presentation. But delayed presentation did not influence outcome at discharge. CONCLUSIONS: Area of residency and gender correlated with delayed presentation after SAH in Japan. Urbanization, male gender, and mild SAH lead patients to delay presentation. The factors underlying these tendencies will be analyzed in a future prospective study.

BACKGROUND <p lang="en">Reperfusion therapy for acute ischemic stroke efficacy is highly time dependent; therefore, stroke centers are required to further reduce the delays from hospital arrival to treatment efficiently. We developed a visual task management application, Task Calculation Stroke (Task Calc. Stroke: TCS), to facilitate hospital acute ischemic stroke treatment by supporting parallel staff task completion. We evaluated TCS for the reduction of reperfusion therapy delays and improvement of clinical outcomes. </p> METHODS <p lang="en">In this multicenter cohort study, patients were directly admitted to 4 comprehensive stroke centers in Japan and given intravenous tissue plasminogen activator and/or mechanical thrombectomy from June 2018 to December 2020. The research team visited each facility and instructed the staff on TCS use for acute ischemic stroke (training stage), after which the staff used TCS independently (TCS stage). We then compared door‐to‐needle time for intravenous tissue plasminogen activator, door‐to‐puncture time for mechanical thrombectomy, and clinical outcomes at discharge according to the modified Rankin Scale among patients treated before training (original stage), during the training stage, or the TCS stage. </p> RESULTS <p lang="en"> During the study period, 316 patients with acute ischemic stroke received reperfusion therapy; of these, 246 received intravenous tissue plasminogen activator and 162 mechanical thrombectomy (including 92 receiving both the treatments). The mean door‐to‐needle time was significantly reduced from 58.0 minutes in the original stage to 54.6 minutes in the training stage ( P =0.049) and 47.8 minutes in the TCS stage ( P &lt;0.001). The door‐to‐puncture time did not change during the training stage; however, in the TCS stage, it significantly reduced from 93.8 minutes in the original stage to 88.5 minutes ( P =0.004). The distribution of modified Rankin Scale scores at discharge significantly shifted favorably at the TCS stage ( P =0.003). </p> CONCLUSION <p lang="en">In this study, TCS application could reduce workflow time for reperfusion therapy and might have led to improved clinical outcomes. </p>

The posterior condylar vein is an emissary vein that connects the extracranial and intracranial venous systems through the posterior condylar canal (PCC). Dural arteriovenous fistulas (DAVF) of the PCC are rare, and only seven cases have been reported. Transvenous embolization (TVE) is the first-line treatment for PCC DAVF and is predominantly performed through the internal jugular vein. Herein, we report a case of PCC DAVF treated with TVE through the deep cervical vein. This is the first case report of a PCC DAVF treated with TVE through the deep cervical vein.

OBJECTIVES: This study aimed to determine the impact of the approval of prothrombin complex concentrates on the treatment of vitamin K antagonist-related intracerebral hemorrhage. MATERIALS AND METHODS: We retrospectively studied all patients with vitamin K antagonist-related intracerebral hemorrhage treated with prothrombin complex concentrate at our institutes between January 2010 and June 2021. Before approval, prothrombin complex concentrate was administered as either 500 or 1000 IU at the physician's discretion (previous dose group). After approval, we adopted the manufacturer's recommended regimen (recommended dose group). The primary outcome was post-administration international normalized ratio. Secondary outcomes were the amount of prothrombin complex concentrate administered and proportion of post-administration international normalized ratio <1.5, hematoma expansion, thrombotic events within 30 days, modified Rankin scale 0-3 at discharge, and in-hospital mortality. RESULTS: Thirty-two and 19 patients in the previous and recommended dose groups, respectively, were included. The post-administration international normalized ratio significantly differed between groups. The prothrombin complex concentrate dose and proportion of patients achieving post-administration international normalized ratio <1.5 were significantly higher in the recommended dose group than in the previous dose group (1500 IU vs. 500 IU, p<0.001 and 100% vs. 68%, p = 0.008). The proportions of hematoma expansion, thromboembolic events, modified Rankin scale 0-3, and mortality did not differ between groups. CONCLUSION: After prothrombin complex concentrate approval, prothrombin time-international normalized ratio correction was more effective with a significant increase in the prothrombin complex concentrates dose for vitamin K antagonist-associated intracerebral hemorrhage; however, there was no apparent difference in clinical outcomes.

OBJECTIVES: The benefit of mechanical thrombectomy for acute ischemic stroke is highly time dependent. However, time to treatment is longer for in-hospital stroke patients than community-onset stroke patients. This study aimed to clarify the cause of this difference. METHODS: A retrospective single-center study was performed to analyze patients with large vessel occlusion who underwent mechanical thrombectomy between January 2017 and December 2019. Patients were divided into in-hospital stroke and community-onset stroke groups. Clinical characteristics and treatment time intervals were compared between groups. RESULTS: One hundred four patients were analyzed: 17 with in-hospital stroke and 87 with community-onset stroke. Patient characteristics did not significantly differ between groups. Median door (stroke recognition)-to-computed tomography time (36 min vs. 14 min, P<0.01) and door-to-puncture time (135 min vs. 117 min, P=0.02) were significantly longer in the in-hospital stroke group than the community-onset stroke group. However, median computed tomography-to-puncture time (104 min vs. 104 min, P=0.47) and puncture-to-reperfusion time (53 min vs. 38 min, P=0.17) did not significantly differ. CONCLUSIONS: Longer door-to-puncture time in in-hospital stroke patients was mostly caused by longer door-to-computed tomography time, which is the initial part of the workflow. An in-hospital stroke protocol that places importance on early stroke specialist consultation and prompt transportation to the computed tomography scanner might hasten treatment and improve outcomes in patients with in-hospital stroke.

We report a case of vertebral artery dissecting aneurysm (VADA) that developed with subarachnoid hemorrhage and was found to be occluded based on subsequent digital subtraction angiography. Few reports have been published on ruptured VADA in which ipsilateral vertebral arteries are occluded. The proper management of this type of aneurysm is controversial. A 44-year-old woman developed a sudden onset headache. Computed tomography and three-dimensional computed tomography were immediately performed and showed subarachnoid hemorrhage and VADA distal to the right posterior inferior cerebellar artery bifurcation. We decided to treat the VADA immediately and performed digital subtraction angiography but found the VADA had spontaneously occluded. We performed coil embolization, including the aneurysm and the parent artery, with reference to the findings of three-dimensional computed tomography. On Day 16, recurrence was considered due to the finding of dilation of the distal end where the coil was embolized. An additional embolization was performed via the posterior communicating artery. No cases of endovascular treatment have been reported in VADA cases in which the rupture site is spontaneously occluded. In such cases, the treatment may be incomplete, so strict follow-up is required.

PURPOSE: Although intracranial dural arteriovenous fistula (DAVF) without retrograde leptomeningeal venous drainage (Borden type I) is reported to have a benign nature, no study has prospectively determined its clinical course. Here, we report a 3-year prospective observational study of Borden type I DAVF. METHODS: From April 2013 to March 2016, consecutive patients with DAVF were screened at 13 study institutions. We collected data on baseline characteristics, clinical symptoms, angiography, and neuroimaging. Patients with Borden type I DAVF received conservative care while palliative intervention was considered when the neurological symptoms were intolerable, and were followed at 6, 12, 24, and 36 months after inclusion. RESULTS: During the study period, 110 patients with intracranial DAVF were screened and 28 patients with Borden type I DAVF were prospectively followed. None of the patients had conversion to higher type of Borden classification or intracranial hemorrhage during follow-up. Five patients showed spontaneous improvement or disappearance of neurological symptoms (5/28, 17.9%), and 5 patients showed a spontaneous decrease or disappearance of shunt flow on imaging during follow-up (5/28, 17.9%). Stenosis or occlusion of the draining sinuses on initial angiography was significantly associated with shunt flow reduction during follow-up (80.0% vs 21.7%, p = 0.02). CONCLUSION: In this 3-year prospective study, patients with Borden type I DAVF showed benign clinical course; none of these patients experienced conversion to higher type of Borden classification or intracranial hemorrhage. The restrictive changes of the draining sinuses at initial diagnosis might be an imaging biomarker for future shunt flow reduction.

The PulseRider (Cerenovus, Johnson & Johnson Medical Devices, New Brunswick, NJ, USA) is a neck reconstruction device that is used for the treatment of unruptured wide-necked bifurcation aneurysms. Herein, we describe the case of a 51-year-old male patient with a basilar apex aneurysm who was treated with PulseRider but had post-procedural brainstem infarctions caused by one of the proximal markers covering the origin of a perforator. In such cases, repositioning of the PulseRider should be performed to avoid infarctions.

Background: Cerebral amyloid angiopathy-related inflammation (CAA-I) presents with slowly progressive nonspecific neurological symptoms, such as headache, cognitive function disorder, and seizures. Pathologically, the deposition of amyloid-β proteins at the cortical vascular wall is a characteristic and definitive finding. Differential diagnoses include infectious encephalitis, neurosarcoidosis, primary central nervous system lymphoma, and glioma. Here, we report a case of CAA-I showing acute progression, suggesting a glioma without enhancement, in which a radiological diagnosis was difficult using standard magnetic resonance imaging. Case Description: An 80-year-old woman was admitted due to transient abnormal behavior. Her initial imaging findings were similar to those of a glioma. She presented with rapid progression of the left hemiplegia and disturbance of consciousness for 6 days after admission and underwent emergent biopsy with a targeted small craniotomy under general anesthesia despite her old age. Intraoperative macroscopic findings followed by a pathological study revealed CAA-I as the definitive diagnosis. Steroid pulse therapy with methylprednisolone followed by oral prednisolone markedly improved both the clinical symptoms and imaging findings. Conclusion: Differential diagnosis between CAA-I and nonenhancing gliomas may be difficult using standard imaging studies in cases presenting with acute progression. A pathological diagnosis under minimally invasive small craniotomy may be an option, even for elderly patients.

BACKGROUND: Recurrent complex middle cerebral artery (MCA) aneurysms after combined clipping and endovascular surgery are challenging, and if conventional techniques are adapted, advanced surgical, endovascular, and a combination of both techniques are often required. For such complex aneurysms, safe and effective straightforward techniques for all neurovascular surgeons are warranted. We describe the details of staged hybrid techniques with straightforward bypass surgery followed by flow diverter deployment in a patient with complex MCA aneurysm. ILLUSTRATIVE CASE: A 69-year-old woman presented with left recurrent large MCA aneurysm enlargement 25 years after direct surgery and coil embolization for ruptured aneurysm. The recurrent MCA aneurysm had large and complex morphology and was adhering to the brain tissues. Therefore, it was unsuitable to treat such aneurysm with conventional surgical and endovascular techniques with a high risk of morbidity. We performed (1) M2 ligation following superficial temporal artery-M2 bypass and (2) flow diverter deployment assisted with coil packing in two sessions. Three months after the second session, the aneurysm was completely occluded with endothelialization of the neck. Angiographic findings revealed no recurrence 12 months after the treatment. CONCLUSIONS: Staged hybrid techniques with straightforward bypass surgery followed by flow diverter deployment may be a safe and effective treatment for complex recurrent MCA aneurysms.

BACKGROUND: We aimed to clarify the relationship between epicardial adipose tissue (EAT) volume and the presence of severe stenoses (SS) on coronary computed tomography angiography (CTA) for risk stratification of the patients with carotid artery stenoses. METHODS: We prospectively performed CTA for 125 consecutive patients (72.4 ± 8.1 years, 85% men) without a history of coronary artery disease (CAD), who were scheduled for carotid artery revascularization from 2014 to 2020. SS was defined as ≥70% luminal stenosis on CTA. EAT was quantified automatically as the total volume of tissue with -190 to -30 HU. RESULTS: Of 125 patients, 76 had SS. Between the patients with and without SS, there were significant differences in coronary artery calcium score (CACS), left ventricular ejection fraction (LVEF), dyslipidemia, and EAT, despite no differences in carotid echocardiography findings. After adjustment for age, gender, and dyslipidemia, EAT was an independent factor associated with SS (p=0.011), as well as CACS and LVEF. The addition of EAT to a baseline model including age, gender, dyslipidemia, LVEF, and CACS achieved both net reclassification improvement (0.505, p=0.003) and integrated discrimination improvement (0.059, p=0.003). CONCLUSIONS: In patients with carotid stenoses, EAT is associated with CAD and is useful for additional risk stratification. Epicardial fat may have a specific role in the development of CAD in patients with suspected systemic atherosclerosis.

PURPOSE: The Flow Re-direction Endoluminal Device (FRED) has recently become available for flow diversion in Japan. We have encountered cases that failed to deploy the FRED. In this study, we report our initial experience with the FRED for cerebral aneurysms and clarify the causes of failed FRED deployment. METHODS: A retrospective data analysis was performed to identify patients treated with the FRED between June 2020 and March 2021. Follow-up digital subtraction angiography was performed at 3 and 6 months and assessed using the O'Kelly-Marotta (OKM) grading scale. RESULTS: Thirty-nine aneurysms in 36 patients (average age: 54.4 years) were treated with the FRED. The average sizes of the dome and neck were 9.9 mm and 5.2 mm, respectively. In nine patients, additional coiling was performed. In one patient (2.6%), proximal vessel injury caused direct carotid-cavernous fistula during deployment. Ischaemic complications were encountered in one patient (2.6%) with transient symptoms. Angiographic follow-up at 6 months revealed OKM grade C or D in 86.6% of patients. FRED deployment was successful in 35 (92.1%) procedures. In the failure group, the differences between the FRED and the minimum vessel diameter (P = 0.04) and the rate of the parent vessel having an S-shaped curve (P = 0.04) were greater than those in the success group. CONCLUSIONS: Flow diversion using the FRED is effective and safe for treating cerebral aneurysms. The use of the FRED for patients with an S-shaped curve in the parent vessel and oversizing of more than 2 mm should be considered carefully.

<bold>Background:</bold> Coronavirus Disease 2019 (COVID-19) has spread worldwide with collateral damage and therefore might affect the behavior of stroke patients with mild symptoms seeking medical attention. <bold>Methods:</bold> Patients with ischemic stroke who were admitted to hospitals within 7 days of onset were retrospectively registered. The clinical characteristics, including onset-to-door time (ODT), of patients with a transient ischemic attack (TIA)/mild stroke (National Institutes of Health Stroke Scale [NIHSS] score of ≤ 3 on admission) or moderate/severe stroke were compared between those admitted from April 2019 to March 2020 (pre-COVID-19 period) and from April to September 2020 (COVID-19 period). Multivariable regression analysis was performed to identify factors associated with the ODT. <bold>Results:</bold> Of 1,100 patients (732 men, median age, 73 years), 754 were admitted during the pre-COVID-19 period, and 346 were admitted during the COVID-19 period. The number and proportion of patients with TIA/minor stroke were 464 (61.5%) in the pre-COVID-19 period and 216 (62.4%) during the COVID-19 period. Among patients with TIA/mild stroke, the ODT was longer in patients admitted during the COVID-19 period compared with that of the pre-COVID-19 period (median 864 min vs. 508 min, <italic>p</italic> = 0.003). Multivariable analysis revealed the COVID-19 period of admission was associated with longer ODT (standardized partial regression coefficient 0.09, <italic>p</italic> = 0.003) after adjustment for age, sex, route of arrival, NIHSS score on admission, and the presence of hypertension, diabetes mellitus, and wake-up stroke. No significant change in the ODT was seen in patients with moderate/severe stroke. <bold>Conclusions:</bold> The COVID-19 epidemic might increase the ODT of patients with TIA/mild stroke.