Endovascular Therapy for Acute Stroke with a Large Ischemic Region.

BACKGROUND: Endovascular therapy for acute ischemic stroke is generally avoided when the infarction is large, but the effect of endovascular therapy with medical care as compared with medical care alone for large strokes has not been well studied. METHODS: We conducted a multicenter, open-label, randomized clinical trial in Japan involving patients with occlusion of large cerebral vessels and sizable strokes on imaging, as indicated by an Alberta Stroke Program Early Computed Tomographic Score (ASPECTS) value of 3 to 5 (on a scale from 0 to 10, with lower values indicating larger infarction). Patients were randomly assigned in a 1:1 ratio to receive endovascular therapy with medical care or medical care alone within 6 hours after they were last known to be well or within 24 hours if there was no early change on fluid-attenuated inversion recovery images. Alteplase (0.6 mg per kilogram of body weight) was used when appropriate in both groups. The primary outcome was a modified Rankin scale score of 0 to 3 (on a scale from 0 to 6, with higher scores indicating greater disability) at 90 days. Secondary outcomes included a shift across the range of modified Rankin scale scores toward a better outcome at 90 days and an improvement of at least 8 points in the National Institutes of Health Stroke Scale (NIHSS) score (range, 0 to 42, with higher scores indicating greater deficit) at 48 hours. RESULTS: A total of 203 patients underwent randomization; 101 patients were assigned to the endovascular-therapy group and 102 to the medical-care group. Approximately 27% of patients in each group received alteplase. The percentage of patients with a modified Rankin scale score of 0 to 3 at 90 days was 31.0% in the endovascular-therapy group and 12.7% in the medical-care group (relative risk, 2.43; 95% confidence interval [CI], 1.35 to 4.37; P = 0.002). The ordinal shift across the range of modified Rankin scale scores generally favored endovascular therapy. An improvement of at least 8 points on the NIHSS score at 48 hours was observed in 31.0% of the patients in the endovascular-therapy group and 8.8% of those in the medical-care group (relative risk, 3.51; 95% CI, 1.76 to 7.00), and any intracranial hemorrhage occurred in 58.0% and 31.4%, respectively (P<0.001). CONCLUSIONS: In a trial conducted in Japan, patients with large cerebral infarctions had better functional outcomes with endovascular therapy than with medical care alone but had more intracranial hemorrhages. (Funded by Mihara Cerebrovascular Disorder Research Promotion Fund and the Japanese Society for Neuroendovascular Therapy; RESCUE-Japan LIMIT ClinicalTrials.gov number, NCT03702413.).

Ulceration location is associated with clinical course in carotid stenosis.

OBJECTIVE: Plaque ulceration in carotid artery stenosis is a risk factor for cerebral ischemic events; however, the characteristics that determine plaque vulnerability are not fully understood. We thus assessed the association between plaque ulceration sites and cerebrovascular ischemic attack. METHODS: We retrospectively collected the clinical data of 72 consecutive patients diagnosed with carotid artery stenosis with plaque ulcers. After excluding patients with pseudo-occlusion, a history of previous carotid endarterectomy or carotid artery stenting before the ulcer was first discovered, follow-up data of less than 1 month, or carotid endarterectomy or carotid artery stenting performed within 1 month after the ulcer was first discovered, 60 patients were ultimately included. Patients were divided into proximal and distal groups based on the ulcer location relative to the most stenotic point. The primary endpoints were ipsilateral cerebrovascular ischemic events ("ischemic events"), such as amaurosis fugax, transient ischemic attack, or ischemic stroke due to carotid artery stenosis with plaque ulceration. The association between ulcer location and ischemic events was also assessed. RESULTS: In the patients with plaque ulcer, more patients had proximal than distal plaque ulcers (39 vs 21; P = .028). The median follow-up duration was 3.8 years (interquartile range, 1.5-6.2 years). Nineteen patients (32%) experienced ischemic event. Ischemic events occurred more frequently in the distal than in the proximal group (18% vs 59%; P = .005). Kaplan-Meier curves demonstrated a significantly shorter event-free time in the distal group (log-rank P = .021). In univariate analysis, distal ulcer location was associated with ischemic events (odds ratio [OR], 2.94; 95% confidence interval [CI], 1.13-7.65; P = .03). Multivariate analysis using two different models also showed that distal ulcer location was independently associated with ischemic events (Model 1: OR, 3.85; 95% CI, 1.26-11.78; P = .03; Model 2: OR, 4.31; 95% CI, 1.49-12.49; P = .009). CONCLUSIONS: Patients with carotid artery stenosis and plaque ulcers located distal to the most stenotic point are more likely to experience cerebrovascular ischemic attacks. Therefore, carotid plaques with ulcers located distal to the most stenotic point may be a potential indication for surgical treatment.

Pathological changes in the lenticulostriate artery indicate the mechanisms leading to intracranial hemorrhage in Moyamoya disease: a case report.

This case report details the pathological findings of a vessel wall identified as the bleeding point for intracranial hemorrhage associated with Moyamoya disease. A 29-year-old woman experienced intracranial hemorrhage unrelated to hyperperfusion following superficial temporal artery-middle cerebral artery bypass surgery. A pseudoaneurysm on the lenticulostriate artery (LSA) was identified as the causative vessel and subsequently excised. Examination of the excised pseudoaneurysm revealed a fragment of the LSA, with a disrupted internal elastic lamina and media degeneration. These pathological findings in a perforating artery, akin to the circle of Willis, provide insights into the underlying mechanisms of hemorrhage in Moyamoya disease.

Irreversible postoperative cognitive impairment after unruptured intracranial aneurysm treatment in the elderly.

PURPOSE: Postoperative cognitive dysfunction and recovery remain unclear in older patients undergoing interventional therapies for unruptured intracranial aneurysms (UIAs). This study aimed to compare changes in postoperative cognitive function between younger and older patients and to detect factors associated with non-recovery from postoperative cognitive dysfunction. METHODS: This study reviewed 59 consecutive patients with UIAs who underwent interventional therapies, including microsurgical clipping or endovascular treatment, from 2021 to 2022. All patients were divided into the older (aged ≥ 70 years) and younger (aged < 70 years) groups. Mini-Mental State Examination (MMSE) and Frontal Assessment Battery (FAB) were performed within 2 months before interventions, at 1 week postoperatively (POW1), and 3-6 months postoperatively (POM3-6). RESULTS: MMSE and FAB scores decreased more frequently in the older group than in the younger group at POW1 (older vs. younger: MMSE: 48% vs. 21%, p < 0.05; FAB: 56% vs. 18%, p < 0.01). In the older group, the FAB Z-score decreased in POW1 and recovered by POM3-6 (p < 0.01), while the MMSE Z-score continued to decrease (p = 0.04). Age and the preoperative MSME Z-score were significantly associated with non-recovery from decreased MMSE score at POM3-6 (recovery vs. non-recovery, age: 62 years old vs. 72 years old, p = 0.03, preoperative MMSE Z-score: 0.16 vs. - 0.90, p < 0.01). CONCLUSIONS: This retrospective study found that older patients were more likely to have a postoperative cognitive decline after UIA treatment and implicated that global cognitive function tended to decline more than executive function in the long term. In addition, this study demonstrated that lower preoperative cognitive function was associated with inadequate postoperative cognitive recovery. The findings potentially contribute to the establishment of indications for treating UIAs in older patients.

Comorbidity burden and outcomes after mechanical thrombectomy for large vessel occlusion: A retrospective analysis.

OBJECTIVES: Patients with acute ischemic stroke (AIS) often have an accumulation of pre-existing comorbidities, but its clinical impact on outcomes after mechanical thrombectomy (MT) remains unknown. Therefore, we examined whether comorbidity burden before AIS onset could predict clinical outcomes after MT. METHODS: In this retrospective cohort, we enrolled consecutive patients with community-onset AIS who underwent MT between April 2016 and December 2021. To evaluate each patient's comorbidity burden, we calculated Charlson comorbidity index (CCI), then classified the patients into the High CCI (≥ 3) and the Low CCI (< 3) groups. The primary outcome was a good neurological outcome at 90 days, defined as a modified Rankin scale 0-2 or no worse than the previous daily conditions. All-cause mortality at 90 days and hemorrhagic complications after MT were also compared between the two groups. We estimated the odds ratios and their confidence intervals using a multivariable logistic regression model. RESULTS: A total of 388 patients were enrolled, of whom 86 (22.2%) were classified into the High CCI group. Patients in the High CCI group were less likely to achieve a good neurological outcome (adjusted odds ratio of 0.26 [95% confidence interval, 0.12-0.58]). Moreover, symptomatic intracranial hemorrhage was more common in the High CCI (14.0% vs. 4.6%; adjusted odds ratio, 4.10 [95% confidence interval, 1.62-10.3]). CONCLUSIONS: Comorbidity burden assessed by CCI was associated with clinical outcomes after MT. CCI has the potential to become a simple and valuable tool for predicting neurological prognosis among patients with AIS and MT.

Pharmacokinetics of Temozolomide in a Patient With Glioblastoma Undergoing Hemodialysis: A Short Communication.

BACKGROUND: Temozolomide (TMZ) is an alkylating agent used to treat glioblastoma. However, the pharmacokinetics of TMZ to establish a treatment strategy for patients undergoing hemodialysis (HD) remain unclear. In this case report, we evaluated the pharmacokinetics and HD removal rate of TMZ in a patient with glioblastoma undergoing HD to determine optimal dosing of TMZ. METHODS: A 78-year-old man with glioblastoma who underwent HD 3 times a week was treated with TMZ concomitant with radiotherapy. One dose of TMZ was prescribed at 75 mg/m 2 on the day before HD and another dose of 37.5 mg/m 2 on the day before non-HD. Peak and trough concentrations (1 hour and 12 hours after dosing, respectively) were evaluated before HD and on non-HD days. HD removal rate of TMZ was calculated based on the predialyzer and postdialyzer plasma concentrations. Furthermore, the TMZ plasma concentrations were measured using liquid chromatography-tandem mass spectrometry. RESULTS: The mean plasma peak and trough concentrations ± SD after 75 mg/m 2 TMZ were 2917 ± 914 and 108 ± 17.6 ng/mL, respectively. Those after 37.5 mg/m 2 TMZ dosage were 1305 ± 650 and 53.8 ± 11.8 ng/mL, respectively. The mean HD TMZ removal rate was 84.9 ± 1.9%. CONCLUSIONS: TMZ was tolerable in patients undergoing HD. Based on the data from a single individual pharmacokinetic perspective, the pharmacokinetics of TMZ in this patient undergoing HD were comparable with those observed in patients with normal renal function. In addition, it may be reasonable to administer TMZ after HD because of the high HD removal rate.

Impact of tailored multimodal treatment for unruptured brain arteriovenous malformation: comparison with a randomized trial of unruptured brain arteriovenous malformations.

PURPOSE: The first randomized controlled study on unruptured brain arteriovenous malformations (bAVM), the ARUBA trial, demonstrate the superiority of medical management; however, it failed to completely rule out the efficacy of therapeutic interventions due to several limitations. This study aimed to examine the outcomes of multimodal interventional treatment for bAVM in terms of safety and efficacy. METHODS: We reviewed 226 consecutive patients with unruptured bAVM admitted to our institute between 2002 and 2022. Treatment methods were divided into medical management and therapeutic intervention, including microsurgery, stereotactic surgery, and endovascular intervention. First, the choice of therapeutic modalities was assessed in the pre-ARUBA (before February 2014) and post-ARUBA (after March 2014) eras. Second, the incidence of symptomatic stroke or death and functional prognosis with a modified Rankin scale (mRS) score of ≥2 at 5 years was compared between the medical management and therapeutic intervention. RESULTS: In the pre- and post-ARUBA groups, 73% and 84% of patients underwent therapeutic interventions, respectively (p = 0.053). The rate of symptomatic stroke or death was lower in patients who underwent interventional therapies than in those who underwent medical management (9.7% vs. 22%, p = 0.022); however, the opposite was observed in the ARUBA trial (31% vs. 10%). The annual incidence of stroke or death was also lower in the interventional therapy group (4.3%/y vs. 1.8%/year, hazard ratio = 0.45, 95% confidence interval: 0.18-1.08, p = 0.032). The rate of mRS score of ≥2 after a 5-year follow-up was 18% and 6% in the medical treatment and intervention groups (p = 0.14). CONCLUSIONS: The therapeutic intervention rate did not decrease, even after the publication of the ARUBA trial. The rate of stroke or death was lower in the intervention group, indicating that a tailored choice of multimodality is safe and effective for managing unruptured bAVM.

PulseRider-assisted coil embolization for an unruptured internal carotid artery-persistent primitive trigeminal artery aneurysm.

A persistent primitive trigeminal artery (PPTA) is a vessel remnant of carotid-vertebrobasilar anastomosis. The aneurysm at the bifurcation of the internal carotid artery (ICA) and PPTA tends to have a broad neck with the branch incorporated into the sac. Because PPTA supplies to the posterior circulation and branches off direct pontine perforators, PPTA preservation should always be considered when treating PPTA aneurysms to avoid ischemic complications.We report a case of the wide-neck ICA-PPTA aneurysm successfully treated with the PulseRider-assisted coil embolization, resulting in complete occlusion with PPTA patency. Relevant anatomy and endovascular strategy of the PPTA aneurysms are discussed.

[Changes in Gamma Knife Radiosurgery(GKRS)in Patients with Metastatic Brain Tumors before and after COVID-19].

The spread of coronavirus disease 2019(COVID-19)is a concern as it may delay the detection of malignant tumors due to delayed medical checkups. We examined changes in the treatment of metastatic brain tumors before and after COVID- 19. A retrospective review of 211 patients with metastatic brain tumors who underwent initial gamma knife radiosurgery between July 2019 and December 2021 was conducted. Data collected include patient age, gender, the Karnofsky performance status(KPS), primary tumor control, number, total volume, and outcome during the COVID-19 emergency declaration period and outside of it. The patient number was 164 outside of the emergency period and 47 during the period. Symptomatic cases(KPS<90)and poor control of the primary site increased during the COVID-19 period. The treatment number and volume of brain metastasis did not change. Metastatic control after 4 months of treatment also showed no difference. The number of symptomatic patients increased during the emergency declaration period, suggesting that COVID- 19 may have reduced the rate of asymptomatic patients being seen. However, these were not enough to affect the prognosis at 4 months. Overall, the COVID-19 pandemic had a small impact on the provision of stereotactic radiotherapy for metastatic brain tumors.

A multicenter prospective registry of Borden type I dural arteriovenous fistula: results of a 3-year follow-up study.

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.

Pipeline flow diversion with adjunctive coil embolization for internal carotid artery aneurysms following an intradural component: results in 46 consecutive aneurysms from a Japanese single-center experience.

In the treatment of an intracranial aneurysm with the flow diverter, the combined use of coil embolization can help promote subsequent progressive thrombosis within the aneurysm sac and reduce the risk of delayed aneurysm rupture. This study retrospectively reviewed outcomes of patients who had undergone the Pipeline Embolization Device (PED) with adjunctive coil embolization (PED/coil) at a single center to determine its safety and efficiency. Patients with internal carotid artery aneurysms following an intradural component were selected for PED/coil between 2015 and 2020. All patients were premedicated with dual antiplatelet therapy of aspirin plus clopidogrel or prasugrel. A minimal number of PEDs were deployed, with coils inserted using a stent-jail technique, avoiding dense packing. A total of 46 aneurysms (43 patients; median dome size, 11.6 mm; median neck width, 6.3 mm) were treated with PED/coil. The median volume embolization ratio was 14.8%. The degree of angiographic filling at the 6-month and latest angiography showed complete occlusion in 60.5% (26/43) and 70.5% (31/44), respectively. Small (< 10 mm) aneurysms achieved a higher complete occlusion rate in the early period; a lower cumulative incidence of aneurysm occlusion was observed in large and giant (≥ 10 mm) aneurysms (P = .024). The median clinical follow-up was 22 months, and no aneurysm ruptures occurred. Favorable clinical outcomes were achieved, with permanent neurological morbidity of 4.7% and no mortality. PED/coil demonstrated a high angiographic occlusion rate at an early stage. Loosely packed coils are sufficient to obliterate aneurysms effectively.

Characterization of Moyamoya and Middle Cerebral Artery Diseases by Carotid Canal Diameter and RNF213 p.R4810K Genotype.

OBJECTIVES: It is sometimes difficult to differentiate middle cerebral artery disease from moyamoya disease because the two can present similarly yet have different treatment strategies. We investigated whether the presence of a narrow carotid canal and the RNF213 mutation can help differentiate between the two phenotypes. POPULATION AND METHODS: We analyzed 78 patients with moyamoya disease, 27 patients with middle cerebral artery disease, and 79 controls from 2 facilities. The carotid canal diameter was measured using computed tomography. The p.R4810K mutation was genotyped by TaqMan assay. A receiver operating characteristics analysis was performed to assess the significance of the carotid canal diameter for the accurate diagnosis of moyamoya disease. RESULTS: The carotid canal diameter was significantly narrower in patients with moyamoya disease than in controls. The optimal cutoff values were 5.0 mm for adult males and 4.5 mm for adult females and children (sensitivity: 0.82; specificity: 0.92). Among the patients with middle cerebral artery disease, 18.5% and 25.0% of the affected hemispheres had the p.R4810K mutation and narrow canal (i.e., below the cutoff), respectively, whereas only 3.1% of those had both. Contrastingly, 68.8% of the affected hemispheres in patients with moyamoya disease had both these characteristics. Among the patients with moyamoya disease, those with the p.R4810K mutation tended to have narrower carotid canals. CONCLUSIONS: Although the presence of a narrow carotid canal or the p.R4810K mutation alone could not be used to distinguish those with moyamoya disease from those with middle cerebral artery disease, the combination of these factors could better characterize the two phenotypes.

[Neurosurgical Emergencies and Coronavirus Infections].

In neurosurgical emergencies during the coronavirus disease 2019(COVID-19)epidemic, both infection prevention and time reduction must be achieved. This requires patient identification, appropriate personal protective equipment(PPE), and zoning. First, based on information from EMS, the possibility of patients being infected with COVID-19 and medical history need to be evaluated. Patients are then classified as positive, suspected, or undetermined for COVID-19; no patient is classified as negative before testing during the epidemic. Patients who are unable to communicate their medical history due to conscious disturbance or aphasia are treated as undetermined or suspected cases of COVID-19. Wearing appropriate PPE is important, especially for undetermined or suspected cases. Although N95 masks are necessary only during procedures in which aerosols are generated, eye or face shields are necessary in situations with a high risk of splash exposure. Use of masks by patients is essential to reduce the risk of exposure. Once the patient arrives at the hospital, precaution should be taken to avoid break down of zoning during transport, in the examination room, and angio-suite. It is important to conduct in-depth simulations to ascertain the number of personnel required and the role and location of each staff member.

Outcomes of Large Vessel Occlusion Stroke in Patients Aged ≥90 Years.

BACKGROUND AND PURPOSE: Outcomes in patients ≥90 years of age with stroke due to large vessel occlusion were compared between endovascular therapy (EVT) and medical management. METHODS: Of 2420 acute ischemic stroke patients with large vessel occlusion in a prospective, multicenter, nationwide registry in Japan, patients aged ≥90 years with occlusion of the internal carotid artery or M1 segment of the middle cerebral artery were included. The primary effectiveness outcome was a favorable outcome at 3 months, defined as achieving a modified Rankin Scale score of 0 to 2 or return to at least the prestroke modified Rankin Scale score at 3 months. Safety outcomes included symptomatic intracranial hemorrhage within 72 hours after onset. Intergroup biases were adjusted by multivariable adjustment with inverse probability of treatment weighting. RESULTS: A total of 150 patients (median age, 92 [interquartile range, 90-94] years; median prestroke modified Rankin Scale score, 2 [interquartile range, 0-4]) were analyzed. EVT was performed in 49 patients (32.7%; mechanical thrombectomy, n=43). The EVT group showed shorter time from onset to hospital arrival (P=0.03), higher Alberta Stroke Program Early CT Score (P<0.01), and a higher rate of treatment with intravenous thrombolysis (P<0.01) than the medical management group. The favorable outcome was seen in 28.6% of the EVT group and 6.9% of the medical management group (P<0.01). EVT was associated with the favorable outcome (adjusted odds ratio, 8.44 [95% CI, 1.88-37.97]). Rates of symptomatic intracranial hemorrhage were similar between the EVT group (0.0%) and the medical management group (3.9%; P=0.30). CONCLUSIONS: Patients who underwent EVT showed better functional outcomes than those with medical management without increased symptomatic intracranial hemorrhages. Given proper patient selection, withholding EVT solely on the basis of the age of patients may not offer the best chance of good outcome. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02419794.

Impact of Procedure Time on Clinical Outcomes of Patients Who Underwent Endovascular Therapy for Acute Ischemic Stroke.

BACKGROUND AND PURPOSE: The time from onset to reperfusion is associated with clinical outcomes in acute ischemic stroke due to large vessel occlusion (LVO); nevertheless, the time limit of the continuing procedure remains unclear. We analyzed the relationship between procedure time and clinical outcomes in patients with LVO who underwent endovascular treatment (EVT). METHODS: We assessed 1,247 patients who underwent EVT for LVO. Data were obtained from our multicenter registry, and patients were included if data on procedure time were available. Multivariate analysis was performed to assess the impact of procedure time on clinical outcomes using the following parameters: favorable outcome (the modified Rankin score of 0-2 at 90 days), mortality within 90 days, symptomatic intracranial hemorrhage within 72 h after stroke onset, and procedure-related complications. RESULTS: The rate of favorable outcomes linearly decreased with increasing procedure time, but there was no linear relationship between procedure time and other outcomes. The adjusted odds ratio for 30-minute delay in procedure time was 0.76 (95% confidence interval, 0.68-0.84) for favorable outcome, 1.15 (0.97-1.36) for mortality, 1.08 (0.87-1.33) for symptomatic intracranial hemorrhage, and 0.92 (0.75-1.16) for complications. Significant interactions in the effect of procedure time on favorable outcome were observed between the subgroups stratified by age (≥75 or <75 years). Younger patients had a greater deleterious effect of delayed reperfusion. CONCLUSIONS: Increasing procedure time was associated with less favorable outcomes, but not with the rate of mortality, symptomatic intracerebral hemorrhage, or complications in our cohort.

Differences in Acute Ischemic Stroke Management and Prognosis between Multiple Large-Vessel Occlusion and Single Large-Vessel Occlusion: Subanalysis of the RESCUE-Japan Registry 2.

INTRODUCTION: The management and prognosis of acute ischemic stroke due to multiple large-vessel occlusion (LVO) (MLVO) are not well scrutinized. We therefore aimed to elucidate the differences in patient characteristics and prognosis of MLVO and single LVO (SLVO). METHODS: The Recovery by Endovascular Salvage for Cerebral Ultra-Acute Embolism Japan Registry 2 (RESCUE-Japan Registry 2) enrolled 2,420 consecutive patients with acute LVO who were admitted within 24 h of onset. We compared patient prognosis between MLVO and SLVO in the favorable outcome, defined as a modified Rankin Scale (mRS) score ≤2, and in mortality at 90 days by adjusting for confounders. Additionally, we stratified MLVO patients into tandem occlusion and different territories, according to the occlusion site information and also examined their characteristics. RESULTS: Among the 2,399 patients registered, 124 (5.2%) had MLVO. Although there was no difference between the 2 groups in terms of hypertension as a risk factor, the mean arterial pressure on admission was significantly higher in MLVO (115 vs. 107 mm Hg, p = 0.004). MLVO in different territories was more likely to be cardioembolic (42.1 vs. 10.4%, p = 0.0002), while MLVO in tandem occlusion was more likely to be atherothrombotic (39.5 vs. 81.3%, p < 0.0001). Among MLVO, tandem occlusion had a significantly longer onset-to-door time than different territories (200 vs. 95 min, p = 0.02); accordingly, the tissue plasminogen activator administration was significantly less in tandem occlusion (22.4 vs. 47.9%, p = 0.003). However, interestingly, the endovascular thrombectomy (EVT) was performed significantly more in tandem occlusion (63.2 vs. 41.7%; adjusted odds ratio [aOR], 2.3; 95% confidence interval [CI], 1.1-5.0). The type of MLVO was the only and significant factor associated with EVT performance in multivariate analysis. The favorable outcomes were obtained less in MLVO than in SLVO (28.2 vs. 37.1%; aOR, 0.48; 95% CI, 0.30-0.76). The mortality rate was not significantly different between MLVO and SLVO (8.9 vs. 11.1%, p = 0.42). DISCUSSION/CONCLUSION: The prognosis of MLVO was significantly worse than that of SLVO. In different territories, we might be able to consider more aggressive EVT interventions.

Clinical Trial of the New Stent Retriever Tron FX for both Proximal and Distal Intracranial Large Vessel Occlusions.

BACKGROUND: In all of randomized controlled trials of mechanical thrombectomy, the target vessels were proximal. Herein we report a clinical trial of the Tron FX stent retriever, including the smallest size of 2/15 mm for distal intracranial large vessel occlusion (LVO). OBJECTIVE: Eligible patients presented within 8 h of onset with proximal or distal LVOs, and the Tron FX 4/20 mm or 2/15 mm were used as the first-line device. METHODS: The primary endpoints were rate of modified Thrombolysis in Cerebral Infarction (mTICI) grade 2a-3 immediately after using Tron FX only, and mortality rate 90 d. We compared the outcomes between sizes 4/20 and 2/15 mm. RESULTS: The clinical trial was conducted in 50 cases, of which 44% presented with distal LVO and 15 cases were treated using only Tron FX 2/15 mm. The overall rate of mTICI grade 2a-3 was 80.0% (75.8% with Tron FX 4/20 mm, and 86.7% with 2/15 mm), and a 90-day modified Rankin Scale ≤ 2 or improvement of National Institute of Health Stroke Scale after thrombectomy ≥ 10 was achieved in 66.7% of cases (61.3% with Tron FX 4/20 mm, and 80.0% with 2/15 mm). The overall 90-day mortality rate was 8.0%, and symptomatic intracranial hemorrhage within 24 h occurred in 2.0% of cases. CONCLUSION: In this clinical trial using the Tron FX, which included the size of 2/15 mm for distal LVO, its efficacy was similar and its safety was superior compared with previous studies.

Endovascular Therapy for Acute Ischemic Stroke in Patients with Large-Vessel Occlusion due to Atherosclerotic Stenosis.

OBJECTIVES: Endovascular therapy (EVT) is safe and effective for acute ischemic stroke (AIS) due to large-vessel occlusion (LVO). However, the influence of the AIS subtype (large-artery atherosclerosis [LAA] or cardioembolism [CE]) on clinical outcome in patients treated with EVT remains unclear. This study aimed to evaluate the differences in clinical results between the two subtypes using data from a multicenter prospective registry (RESCUE-Japan Registry 2). MATERIALS AND METHODS: Among 2420 patients in RESCUE-Japan Registry, 682 patients who were diagnosed with LAA or CE were enrolled. The primary outcome was a modified Rankin Scale (mRS) score of 0-2 at 90 days. The secondary outcomes were 90-day mRS 0-1, 0-3, and 6. The relationship between time from onset and clinical outcome was also analyzed. RESULTS: Among the 682 patients, 124 were classified into the LAA group and 558 into the CE group. The baseline National Institutes of Health Stroke Scale score was significantly lower (median 15 vs. 18, p < 0.001). At 90 days, mRS 0-2 was observed in 54 of 124 patients (44%) in the LAA group and 232 of 558 patients (42%) in the CE group (p = 0.69). The proportion of patients with mRS 0-2 tended to decrease according to onset-to-puncture time in the CE group but not in the LAA group (ptrend=0.0007). CONCLUSIONS: The rate of good outcome was similar between LVO due to LAA and CE. However, the rate of favorable outcome did not decrease according to onset-to-puncture time in the LAA group.

A Damp-and-Push Technique for the Copolymer (Onyx) Embolization of Dural Arteriovenous Fistula.

BACKGROUND: Copolymer (Onyx) embolization is an effective treatment for dural arteriovenous fistula (dAVF), however, some dAVFs have multiple, high-flow feeding vessels, resulting in insufficient embolization. For the treatment of such patients, we have developed a novel flow-control technique, the 'damp-and-push technique'. The purpose of this study was to evaluate the technical efficiency and safety of this technique. METHODS: Seven patients who had been diagnosed with intracranial dAVF were treated by transarterial Onyx embolization using the damp-and-push technique between 2016 and 2019. This technique was designed to reduce blood flow to the shunt site using a balloon catheter in the major feeding vessel other than the one injected with Onyx, leading to better Onyx penetration and enabling more controlled embolization of complex dAVFs. Retrospectively collected data were reviewed to assess the occlusion rates and clinical outcomes. RESULTS: The dAVF was at a transverse sinus-sigmoid sinus junction in four patients, in the superior sagittal sinus in two, and in the tentorium in one. Five cases were Cognard type Ⅱb and two cases were Cognard type Ⅳ. All the patients were treated by transarterial Onyx injection via the main feeding vessel, combined with flow reduction in the other main feeding vessel using a balloon catheter. Complete occlusion was achieved in six patients and elimination of cerebral venous reflux was achieved in all the patients. There were no immediate or delayed post-interventional complications. CONCLUSIONS: Transarterial Onyx embolization of dAVF using the damp-and-push technique is safe and yields a high complete occlusion rate.

[Indications and Usage of New Devices such as PulseRider and W-EB for Bifurcation-type Aneurysms].

Bifurcation-type aneurysms located at the basilar tip, anterior communicating artery, and middle cerebral artery are difficult to treat by endovascular coil embolization. One reason for this is that it is impossible to completely cover the aneurysm neck with a single stent because of the branching of two large vessels at the location. Moreover, the parent artery blood flows directly into the aneurysm dome and induces recanalization of the placed coils. In 2020, new devices for bifurcation aneurysms, such as PulseRider and W-EB, were approved in Japan. PulseRider has been in use since September, and W-EB is expected to be available by the end of the year. PulseRider has unique leaflets, which easily cover the broad neck of bifurcation aneurysms and prevent the coil from protruding into the parent artery. W-EB is a nitinol self-expandable mesh ball implant that can prevent blood flow into the aneurysm and subsequent induced thrombosis by deployment in the aneurysm sac. Although we do not yet completely know the features and advantages of either, we expect these two new devices to improve endovascular treatment of bifurcation-type aneurysms that thus far have been difficult to treat.