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Purpose: The aim of this study is to assess the effect of super-resolution deep learning-based reconstruction (SR-DLR), which uses k-space properties, on image quality of intracranial time-of-flight (TOF) magnetic resonance angiography (MRA) at 3 T. Methods: This retrospective study involved 35 patients who underwent intracranial TOF-MRA using a 3-T MRI system with SR-DLR based on k-space properties in October and November 2022. We reconstructed MRA with SR-DLR (matrix = 1008 × 1008) and MRA without SR-DLR (matrix = 336 × 336). We measured the signal-to-noise ratio (SNR), contrast, and contrast-to-noise ratio (CNR) in the basilar artery (BA) and the anterior cerebral artery (ACA) and the sharpness of the posterior cerebral artery (PCA) using the slope of the signal intensity profile curve at the half-peak points. Two radiologists evaluated image noise, artifacts, contrast, sharpness, and overall image quality of the two image types using a 4-point scale. We compared quantitative and qualitative scores between images with and without SR-DLR using the Wilcoxon signed-rank test. Results: The SNRs, contrasts, and CNRs were all significantly higher in images with SR-DLR than those without SR-DLR (p < 0.001). The slope was significantly greater in images with SR-DLR than those without SR-DLR (p < 0.001). The qualitative scores in MRAs with SR-DLR were all significantly higher than MRAs without SR-DLR (p < 0.001). Conclusion: SR-DLR with k-space properties can offer the benefits of increased spatial resolution without the associated drawbacks of longer scan times and reduced SNR and CNR in intracranial MRA. [ABSTRACT FROM AUTHOR]

Purpose: Basilar artery stenosis (BAS) carries high morbidity and mortality, with variable outcomes after endovascular treatments. We systematically reviewed the literature on percutaneous transluminal angioplasty and/or stenting (PTAS) for BAS. Methods: PubMed, EMBASE, Web-of-Science, Scopus, and Cochrane were searched upon the PRISMA guidelines to include prospective/retrospective cohort studies describing PTAS for BAS. Pooled rates of intervention-related complications and outcomes were analyzed with random-effect model meta-analyses. Results: We included 25 retrospective cohort studies comprising 1016 patients. All patients were symptomatic, presenting with transient ischemic attack or ischemic stroke. BAS frequently involved the middle basilar artery (51.4%), mostly classified as Mori-B (57.4%). PTAS for BAS was indicated in severe (≥ 50–70%), symptomatic BAS refractory to dual antiplatelet therapy. Patients underwent angioplasty (95.5%) and/or stenting (92.2%), preferably using Wingspan or Apollo stents. Median baseline BAS was 81% (range, 53–99%), while median post-intervention BAS was 13% (0–75%). Actuarial rates of successful intervention and "good" final outcome were 100% (95% CI: 100–100%) and 89% (95% CI: 85–93%). Intervention-related recurrent ischemic stroke occurred in 85 patients (8.3%) with actuarial rates of 5% (95% CI: 4–7%), differentiated into perforator (5.4%), in-stent (2.6%), and embolic (0.4%). Actuarial rates of intervention-related dissection, restenosis, and death were 0% (95% CI: 0–0%), 1% (95% CI: 0–1%), and 0% (95% CI: 0–2%). Conclusion: Elective PTAS appears to be safe and effective in selected patients with medically refractory, severe, symptomatic, and non-acute BAS. Different stent types and angioplasty-assisted procedures should be considered based on specific clinico-radiological characteristics of the lesions. Future randomized controlled trials are required to corroborate these findings. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study is to test the prognostic value of a diffusion-weighted imaging (DWI) score in acute basilar artery occlusion (ABAO) with successful recanalization. Methods: The DWI-based pons-midbrain and thalamus (PMT) score was developed to assess posterior circulation infarcts. We test its prognostic value and compare it with other two established scales, the DWI-based posterior circulation acute stroke prognosis Early CT score (PC-ASPECTS) and brain stem score (BSS). A retrospective cohort of consecutive ABAO patients with pretreatment magnetic resonance imaging and successful recanalization (defined as modified Thrombolysis in Cerebral Infarction 2b-3) were analyzed. A favorable outcome was defined as a 90-day modified Rankin Scale (mRS) score of 2 or less. The prognostic performance of three scales was estimated by receiver operating characteristic (ROC) curve analyses. Results: One hundred and sixteen eligible patients (mean age, 59.1 ± 11.7 [standard deviation]; 96 [82.8%] man) were included and evaluated. Between favorable (mRS ≤ 2) and unfavorable groups, the baseline PMT score (median [interquartile range], 3 [1–4] versus 6 [5–8]; P < 0.001) differs significantly. ROC curve analyses showed the PMT score had the best prognostic value for favorable outcome (area under the curve, PMT versus BSS versus PC-ASPECTS = 0.80 versus 0.72 versus 0.68, P = 0.010). Multivariate logistic regression analyses showed baseline National Institute of Health stroke scale (OR, 0.90 [95%CI, 0.86–0.95], P = 0.004) and PMT score < 5 (OR, 17.83 [95%CI, 3.91–81.19], P < 0.001) were independent prognostic factors of favorable outcome. Conclusions: The PMT score seems to predict clinical outcome of ABAO patients with successful recanalization. [ABSTRACT FROM AUTHOR]

Purpose: We aimed to investigate the impact of post-thrombectomy isolated subarachnoid hemorrhage (i-SAH) and other types of intracranial hemorrhage (o-ICH) on patient’s neurological outcomes.Stroke data from 2018 to 2022 in a tertiary care center were retrospectively analyzed. Patients with large vessel occlusion from ICA to M2 branch were included. Post-thrombectomy intracranial hemorrhages at 24 h were categorized with Heidelberg Bleeding Classification. Neurological impairment of patients was continuously assessed at admission, at 24 h, 48 h and 72 h, and at discharge. Predictors of i-SAH and o-ICH were assessed.297 patients were included. i-SAH and o-ICH were found in 12.1% (36/297) and 11.4% (34/297) of patients. Overall, NIHSS of i-SAH patients at discharge were comparable to o-ICH patients (median 22 vs. 21, p = 0.889) and were significantly higher than in non-ICH patients (22 vs. 7, p < 0.001). i-SAH often resulted in abrupt deterioration of patient’s neurological symptoms at 24 h after thrombectomy. Compared to non-ICH patients, the occurrence of i-SAH was frequently associated with worse neurological outcome at discharge (median NIHSS increase of 4 vs. decrease of 4, p < 0.001) and higher in-hospital mortality (41.7% vs. 23.8%, p = 0.022). Regardless of successful reperfusion (TICI 2b/3), the beneficial impact of thrombectomy appeared to be outweighed by the adverse effect of i-SAH. Incomplete reperfusion and shorter time from symptom onset to admission were associated with higher probability of i-SAH, whereas longer procedure time and lower baseline ASPECTS were predictive for o-ICH occurrence.Post-thrombectomy isolated subarachnoid hemorrhage is a common complication with significant negative impact on neurological outcome.Methods: We aimed to investigate the impact of post-thrombectomy isolated subarachnoid hemorrhage (i-SAH) and other types of intracranial hemorrhage (o-ICH) on patient’s neurological outcomes.Stroke data from 2018 to 2022 in a tertiary care center were retrospectively analyzed. Patients with large vessel occlusion from ICA to M2 branch were included. Post-thrombectomy intracranial hemorrhages at 24 h were categorized with Heidelberg Bleeding Classification. Neurological impairment of patients was continuously assessed at admission, at 24 h, 48 h and 72 h, and at discharge. Predictors of i-SAH and o-ICH were assessed.297 patients were included. i-SAH and o-ICH were found in 12.1% (36/297) and 11.4% (34/297) of patients. Overall, NIHSS of i-SAH patients at discharge were comparable to o-ICH patients (median 22 vs. 21, p = 0.889) and were significantly higher than in non-ICH patients (22 vs. 7, p < 0.001). i-SAH often resulted in abrupt deterioration of patient’s neurological symptoms at 24 h after thrombectomy. Compared to non-ICH patients, the occurrence of i-SAH was frequently associated with worse neurological outcome at discharge (median NIHSS increase of 4 vs. decrease of 4, p < 0.001) and higher in-hospital mortality (41.7% vs. 23.8%, p = 0.022). Regardless of successful reperfusion (TICI 2b/3), the beneficial impact of thrombectomy appeared to be outweighed by the adverse effect of i-SAH. Incomplete reperfusion and shorter time from symptom onset to admission were associated with higher probability of i-SAH, whereas longer procedure time and lower baseline ASPECTS were predictive for o-ICH occurrence.Post-thrombectomy isolated subarachnoid hemorrhage is a common complication with significant negative impact on neurological outcome.Results: We aimed to investigate the impact of post-thrombectomy isolated subarachnoid hemorrhage (i-SAH) and other types of intracranial hemorrhage (o-ICH) on patient’s neurological outcomes.Stroke data from 2018 to 2022 in a tertiary care center were retrospectively analyzed. Patients with large vessel occlusion from ICA to M2 branch were included. Post-thrombectomy intracranial hemorrhages at 24 h were categorized with Heidelberg Bleeding Classification. Neurological impairment of patients was continuously assessed at admission, at 24 h, 48 h and 72 h, and at discharge. Predictors of i-SAH and o-ICH were assessed.297 patients were included. i-SAH and o-ICH were found in 12.1% (36/297) and 11.4% (34/297) of patients. Overall, NIHSS of i-SAH patients at discharge were comparable to o-ICH patients (median 22 vs. 21, p = 0.889) and were significantly higher than in non-ICH patients (22 vs. 7, p < 0.001). i-SAH often resulted in abrupt deterioration of patient’s neurological symptoms at 24 h after thrombectomy. Compared to non-ICH patients, the occurrence of i-SAH was frequently associated with worse neurological outcome at discharge (median NIHSS increase of 4 vs. decrease of 4, p < 0.001) and higher in-hospital mortality (41.7% vs. 23.8%, p = 0.022). Regardless of successful reperfusion (TICI 2b/3), the beneficial impact of thrombectomy appeared to be outweighed by the adverse effect of i-SAH. Incomplete reperfusion and shorter time from symptom onset to admission were associated with higher probability of i-SAH, whereas longer procedure time and lower baseline ASPECTS were predictive for o-ICH occurrence.Post-thrombectomy isolated subarachnoid hemorrhage is a common complication with significant negative impact on neurological outcome.Conclusion: We aimed to investigate the impact of post-thrombectomy isolated subarachnoid hemorrhage (i-SAH) and other types of intracranial hemorrhage (o-ICH) on patient’s neurological outcomes.Stroke data from 2018 to 2022 in a tertiary care center were retrospectively analyzed. Patients with large vessel occlusion from ICA to M2 branch were included. Post-thrombectomy intracranial hemorrhages at 24 h were categorized with Heidelberg Bleeding Classification. Neurological impairment of patients was continuously assessed at admission, at 24 h, 48 h and 72 h, and at discharge. Predictors of i-SAH and o-ICH were assessed.297 patients were included. i-SAH and o-ICH were found in 12.1% (36/297) and 11.4% (34/297) of patients. Overall, NIHSS of i-SAH patients at discharge were comparable to o-ICH patients (median 22 vs. 21, p = 0.889) and were significantly higher than in non-ICH patients (22 vs. 7, p < 0.001). i-SAH often resulted in abrupt deterioration of patient’s neurological symptoms at 24 h after thrombectomy. Compared to non-ICH patients, the occurrence of i-SAH was frequently associated with worse neurological outcome at discharge (median NIHSS increase of 4 vs. decrease of 4, p < 0.001) and higher in-hospital mortality (41.7% vs. 23.8%, p = 0.022). Regardless of successful reperfusion (TICI 2b/3), the beneficial impact of thrombectomy appeared to be outweighed by the adverse effect of i-SAH. Incomplete reperfusion and shorter time from symptom onset to admission were associated with higher probability of i-SAH, whereas longer procedure time and lower baseline ASPECTS were predictive for o-ICH occurrence.Post-thrombectomy isolated subarachnoid hemorrhage is a common complication with significant negative impact on neurological outcome. [ABSTRACT FROM AUTHOR]

Purpose: The relationship between posterior-circulation lesion volume (PCLV) and clinical outcomes is poorly investigated. We aimed to analyze, in patients with acute basilar artery occlusion (ABAO), if pre-endovascular treatment (EVT) PCLV was a predictor of outcomes. Methods: We analyzed consecutive MRI selected, endovascularly treated ABAO patients. Baseline PCLV was measured in milliliters on apparent diffusion-coefficient map reconstruction. Univariable and multivariable logistic models were used to test if PCLV was a predictor of 90-day outcomes. After the received operating characteristic (ROC) analysis, the optimal cut-off was determined to evaluate the prognostic value of PCLV. Results: A total of 110 ABAO patients were included. The median PCLV was 4.4 ml (interquartile range, 1.3–21.2 ml). Successful reperfusion was achieved in 81.8% of cases after EVT. At 90 days, 31.8% of patients had a modified Rankin scale ≤ 2, and the mortality rate was 40.9%. PCLV was an independent predictor of functional independence and mortality (odds ratio [OR]:0.57, 95% confidence interval [CI], 0.34–0.93 and 1.84, 95% CI, 1.23–2.76, respectively). The ROC analysis showed that a baseline PCLV ≤ 8.7 ml was the optimal cut-off to predict the 90-day functional independence (area under the curve [AUC] = 0.68, 95% CI, 0.57–0.79, sensitivity 88.6%, and specificity 49.3%). In addition, a PCLV ≥ 9.1 ml was the optimal cut-off for the prediction of 90-day mortality (AUC = 0.71, 95% CI, 0.61–0.82, sensitivity 80%, and specificity 60%). Conclusions: Pre-treatment PCLV was an independent predictor of 90-day outcomes in ABAO. A PCLV ≤ 8.7 and ≥ 9.1 ml may identify patients with a higher possibility to achieve independence and a higher risk of death at 90 days, respectively. [ABSTRACT FROM AUTHOR]

To report the occurrence of non-ischemic cerebral enhancing (NICE) lesions following mechanical thrombectomy (MT) through the retrospective French nationwide registry of NICE lesions. All thrombectomy capable stroke centers (TSC) in France were invited to fill out a questionnaire disseminated through a trainee-led research network (JENI-RC: Jeunes en Neuroradiologie Interventionnelle-Research Collaborative). NICE lesions were defined according to previous literature as delayed onset punctate, nodular, or annular foci enhancements with peri-lesion edema and vascular distribution in the territory of the MT with no other confounding disease. All 43 TSC French centers responded. Three patients were reported by 3 different centers over a total of 34,824 MT (2015–2020). Patient no. 1 developed symptomatic NICE lesions 8 weeks after MT with combination of aspiration and stentriever for a right middle cerebral artery occlusion. Patient no. 2 developed asymptomatic NICE lesions 5 weeks after MT with direct thromboaspiration for a right middle cerebral artery occlusion. Patient no. 3 developed symptomatic NICE lesions 6 weeks after MT with direct thromboaspiration, and combination of aspiration and stentriever for a basilar artery occlusion. This study provides evidence that NICE lesions following MT are a possible rare complication with a similar presentation as previously described following endovascular aneurysm treatment. Both radiologists and neurologists should be aware of this adverse event and make use of MRI contrast agents in case of unexplained symptoms/images during follow-up after MT. [ABSTRACT FROM AUTHOR]

Purpose: We present the first nationwide study on endovascular therapy for basilar artery occlusion (BAO) from early hospital management to 3-month outcome. Methods: Data were collected on all acute ischaemic stroke patients registered 2016–2019 in the two national quality registers for stroke care and endovascular therapy (EVT), receiving EVT for BAO and subclassified into proximal, middle and distal. Results: In all, 251 patients were included: 69 proximal, 73 middle and 109 distal BAO. Patients with proximal BAO were younger (66, middle 71, distal 76, p < 0.0001), less often female (27.5%, middle 47.9%, distal 47.7%, p = 0.015), more often smokers (28.6%, middle 20.3%, distal 11.5%, p < 0.0001), and fewer had atrial fibrillation (13.2%, middle 24.7%, distal 48.6%, p < 0.0001). Level of consciousness and NIHSS score did not differ by BAO subtype and 52.2% were alert on admission. Time from groin puncture to revascularization was significantly longer in patients with proximal BAO (71, middle 46, distal 42 min, p < 0.0001), and angioplasty and/or stenting was more often performed in patients with proximal (43.4%) and middle (27.4%) than distal (6.4%) BAO (p < 0.0001). Cumulative 90-day mortality was 38.6% (proximal 50.7%, middle 32.9%, distal 34.9%, p = 0.02). Older and pre-stroke dependent patients had higher mortality, as did patients in whom angioplasty/stenting was performed. Conclusion: We confirm a serious outcome in BAO despite endovascular therapies, and demonstrate important differences relating to occlusion location in baseline characteristics, procedural time, therapeutic measures and outcome. Further in-depth analyses of factors affecting outcome in BAO are warranted. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the difference in mechanical thrombectomy (MT) outcomes between vertebrobasilar tandem occlusion (VBTO) and isolated basilar artery (BA) occlusion (non-VBTO) and the difference in rates of successful recanalization between the clean-road and dirty-road pathways, in VBTO. Methods: We conducted a meta-analysis after searching PubMed, EMBASE, and Google Scholar databases as of April 2021. We only included adult patients who underwent MT to treat acute ischemic stroke (AIS) due to VBTO, and the following outcomes should be reported: successful recanalization, functional outcome at 90 days, and symptomatic intracerebral hemorrhage (sICH). The main effect size measures were odds ratio and risk difference, and the software used was RevMan 5.4. Results: The analysis included 81 VBTO and 324 non-VBTO patients (seven studies). We found no significant difference regarding 3 m functional independence [4 studies: OR = 1.71 (95% CI, 0.54, 5.43), I2 = 75%], 3 m mortality [4 studies: OR = 1.62 (95% CI, 0.62, 4.25), I2 = 66%], sICH [4 studies: OR = 1.71 (95% CI, 0.67, 4.39), I2 = 0%], and successful recanalization [3 studies: OR = 0.81 (95% CI, 0.12, 5.57), I2 = 80%]. A subgroup analysis of 118 VBTO patients (five studies) showed no significant difference in successful recanalization between clean-road and dirty-road pathways [RD = 0.07 (95% CI, − 0.09, 0.24), I2 = 40%]. Conclusion: The results of this meta-analysis support the use of MT for AIS patients with VBTO. In VBTO patients, none of the clean-road or dirty-road pathways proved to be superior to the other. [ABSTRACT FROM AUTHOR]

Endovascular treatment for partially thrombosed giant basilar tip aneurysms has not been established because of its low cure rate and numerous associated comorbidities. Although some authors reported the growth mechanism of partially thrombosed aneurysm, there is no report for the process of its shrinkage after treatment. We describe a case of a partially thrombosed giant basilar tip aneurysm presenting with disturbance of consciousness because of a mass effect and brain edema. The patient underwent stent-assisted coiling using a low-profile visualized intraluminal support stent (Terumo). Although pre-operative magnetic resonance imaging (MRI) and angiography revealed prominent neovascularization of the inner aneurysmal layer, this vessel was absent on follow-up angiography 1 month after treatment. Repeat angiography demonstrated the gradual recanalization of the aneurysm. However, repeat MRI examinations showed remarkable shrinkage of the thrombosed aneurysm, and the complete disappearance of the thrombosed component was noted 6 months after treatment. The disappearance of neovascularization 1 month after the treatment may have contributed to the shrinkage of the thrombosed aneurysm. Stent-assisted coiling combined with alteration caused a hemodynamic change in this aneurysm, and the flow-diverting effect might have controlled this partially thrombosed giant aneurysm. [ABSTRACT FROM AUTHOR]

Purpose: Previous studies have indicated that cerebral arterial morphology is linked to aging and some cerebrovascular diseases. However, the mechanisms of morphological changes remain unclear. This study evaluated age-related positional changes in the basilar artery (BA) bifurcation based on longitudinal computed tomography angiography (CTA) data. Methods: This retrospective study evaluated clinical and imaging data from 72 subjects who underwent two CTA scans between July 2011 and August 2019. Three-dimensional (3D) models were reconstructed for each subject based on the two CTA scans with the longest separating interval. Skull landmarks were used to fuse the two models, and the fused model was used to evaluate positional changes in the BA bifurcation. Univariable and multivariable analyses were used to identify variables that were correlated to BA bifurcation shifting. Pearson's correlation test was used to analyze the correlation between the shifting distance and change in the BA bifurcation angle. Results: Significant differences between aneurysm and non-aneurysm cases were observed in terms of sex (p = 0.004), CTA scan interval (p = 0.023), and BA bifurcation shifting distance (p = 0.007). Multivariable linear regression analysis revealed that the BA bifurcation shifting distance was significantly correlated with the CTA scan interval (p = 0.038) and the presence of aneurysms (p < 0.001). Furthermore, the shifting distance was positively correlated with widening of the BA bifurcation angle (p = 0.002). Conclusions: Aging-related widening of the BA bifurcation angle may be related to distal shifting of the BA bifurcation's position, and larger distal shifting of the BA bifurcation may be associated with the risk of aneurysm formation. [ABSTRACT FROM AUTHOR]

Purpose: This study aims to compare endosaccular flow disruptor (EFD) for treatment of basilar tip aneurysm (BTA) with coiling in terms of safety and efficacy. Methods: We retrospectively reviewed patients treated with an EFD for BTAs at our institution between 2013 and 2019 to standard coiling from the same period (control group). Patient demographics, aneurysm characteristics, procedural data, complications and clinical and angiographic outcome were compared between groups. Results: Twenty-three (56%) patients were treated with an EFD and eighteen (44%) patients were treated with coiling. Average aneurysm size was 8 mm in the EFD group and 6.9 mm in the coiling group, respectively (P = 0.2). Average fluoroscopy time, treatment DAP and air kerma were 33 min, 76 Gycm2 and 1.7 Gy in the EFD group and 81 min, 152 Gycm2 and 3.8 Gy in the coiling group, respectively (P < 0.001). In the EFD group, clinically relevant thromboembolic complications occurred in one patient (4%) vs. in 5 patients (28%) in the coiling group (P = 0.07). In each group, 4 patients had an unfavourable outcome at discharge (P = 0.7). Adequate occlusion rates were 96% in the EFD group and 100% and coiling group. Six (26%) patients were prescribed long-term antiplatelet therapy in the EFD group vs. eleven (61%) patients in the coiling group (P = 0.02). Conclusion: Both treatment concepts provided similar technical success and safety. However, procedure time, radiation exposure and a need for long-term antiaggregation were lower with EFD. [ABSTRACT FROM AUTHOR]

Purpose: To determine the radiation exposure in endovascular stroke treatment (EST) of acute basilar artery occlusions (BAO) and compare it with radiation exposure of EST for embolic middle cerebral artery occlusions (MCAO). Methods: In this retrospective analysis of an institutional review board−approved prospective stroke database of a comprehensive stroke center, we focused on radiation exposure (as per dose area product in Gy × cm2, median (IQR)), procedure time, and fluoroscopy time (in minutes, median [IQR]) in patients receiving EST for BAO. Patients who received EST for BAO were matched case by case with patients who received EST for MCAO according to number of thrombectomy attempts, target vessel reperfusion result, and thrombectomy technique. Results: Overall 180 patients (n = 90 in each group) were included in this analysis. General anesthesia was conducted more often during EST of BAO (BAO: 75 (83.3%); MCAO: 18 (31.1%), p < 0.001). Procedure time (BAO: 31 (20–43); MCAO: 27 (18–38); p value 0.226) and fluoroscopy time (BAO: 29 (20–59); MCAO: 29 (17–49), p value 0.317) were comparable. Radiation exposure was significantly higher in patients receiving EST for BAO (BAO: 123.4 (78.7–204.2); MCAO: 94.3 (65.5–163.7), p value 0.046), which represents an increase by 23.7%. Conclusion: Endovascular stroke treatment of basilar artery occlusions is associated with a higher radiation exposure compared with treatment of middle cerebral artery occlusions. [ABSTRACT FROM AUTHOR]

Purpose: To analyze the safety and efficacy of primary endovascular treatment (EVT) for acute ischemic stroke (AIS) in patients younger than 18 years of age. Methods: Review of 4 patients < 18 years of age with AIS, prospectively enrolled in an electronic database registry for acute ischemic stroke patients who underwent thrombectomy at tertiary centers, from January 2011 to February 2017. Clinical and imaging data were analyzed. Results: All patients were female. Patients 1 to 4 were 14, 13, 16, and 13 years old, respectively. Patients 1 and 3 had left middle cerebral artery occlusion, patient 2 basilar occlusion, and patient 4 right tandem occlusion. Mean NIHSS score was 13 (7–19) on arrival and 4 (0–5) at 24 h. Patient 2 had Osler–Weber–Rendu disease and patient 4 a previously surgically repaired complete atrioventricular canal. All patients presented with clinical–radiological mismatch. CT/CTA was used in patients 1 and 4 and MRI/MRA in patients 2 and 3. Stent retriever was used in 3 patients (patients 1, 3, and 4) and direct aspiration first-pass technique in 1 (patient 2). All 4 procedures resulted in successful recanalization and 3-month functional independence. Conclusion: Primary EVT is reported in patients 13 to 16 years of age with AIS due to large vessel occlusion and clinical–radiological mismatch. Procedures were safe and effective with prompt recanalization and good clinical outcome. [ABSTRACT FROM AUTHOR]

Purpose: Acute vertebrobasilar occlusion (VBO) has a grave clinical course; however, thrombectomy in VBO patients has rarely been reported. We retrospectively evaluated the clinical and radiological outcomes of thrombectomy in VBO patients. Methods: From March 2010 to December 2017, 38 patients with 40 acute VBOs underwent thrombectomy at our hospital. Thrombectomy was performed using catheter aspiration (n = 11, 26.8%) or a stent retriever (n = 29, 70.7%). Results: Good clinical outcomes (3-month modified Rankin scale (mRS) of 2 or lower) were achieved in 9 cases (22.5%), and successful recanalization (thrombolysis in cerebral infarction (TICI) grade of 2b or 3) was achieved in 35 cases (87.5%). Good clinical outcomes were significantly related to aetiologies other than atherosclerosis (p = 0.020) and lower National Institutes of Health Stroke Scale (NIHSS) scores on admission (p = 0.025). The clinical and radiological outcomes did not differ significantly between catheter aspiration and stent retriever thrombectomy (p = 1.000 and p = 0.603, respectively); however, stent retriever thrombectomy had a shorter procedure time than catheter aspiration (59.7 ± 31.2 vs. 84.5 ± 35.1 min, p = 0.037). Conclusion: In our series, good clinical outcomes were associated with a lower NIHSS score on admission and stroke aetiologies other than atherosclerosis. The two thrombectomy modalities showed similar clinical and radiological outcomes. However, stent retrievers seemed to allow more rapid recanalization than catheter aspiration in VBO. [ABSTRACT FROM AUTHOR]

Purpose: The beneficial effect of endovascular treatment (EVT) for patients with acute basilar artery occlusion (ABAO) remains uncertain. The purpose of the present study was to evaluate clinical outcome of EVT for patients with ABAO and analyze prognostic factors of good outcome.Methods: From our prospectively established database, we reviewed all patients with ABAO receiving EVT during January 2014 to December 2016. Baseline characteristics and outcomes were evaluated. Favorable functional outcome was defined as modified Rankin Scale score of 0 to 3 assessed at 3-month follow-up. The association between clinical and procedural characteristics and functional outcome was assessed.Results: Of the 68 patients included, 50 patients (73.5%) received mechanical thrombectomy with stent retriever device. Successful reperfusion (thrombolysis in cerebral infarction grades 2b-3) was achieved in 61 patients (89.7%). Overall favorable functional outcome was reached by 31 patients (45.6%). In univariate analysis, Glasgow Coma Scale sum score, baseline National Institutes of Health stroke scale score (NIHSS), and baseline glycemia level were identified predicting good clinical outcome. Multivariate analysis showed that lower NIHSS was the only independent risk factor of favorable functional outcome (OR 0.832; 95% CI, 0.715-0.968; p = 0.018). No difference of favorable outcomes was observed between the subgroups of time to EVT < 6 h and ≽ 6 h.Conclusions: Data in the present study suggests that EVT for ABAO patients should be reasonable within 24 h of symptom onset. The most important factor determining clinical outcome is initial stroke severity. [ABSTRACT FROM AUTHOR]

Introduction: The study aimed to compare efficacy and safety of aspiration thrombectomy (AT) to stentriever thrombectomy (SRT) in patients with basilar artery (BA) occlusion (BAO). Methods: We retrospectively included patients with the following characteristics: acute BAO or occlusion of the intracranial vertebral artery (ICVA) and endovascular therapy (EVT) with stentriever (SRT) or aspiration thrombectomy (AT). Additional extra- but not intracranial EVT and intravenous thrombolysis (IVT) were allowed. Results: Between January 2013 and April 2016, 33 patients fulfilled the criteria (13 treated with SRT, 20 with AT). Prior to EVT, 23 (70%) patients received IVT. The proximal intracranial occlusion was ICVA in 2 patients, proximal BA in 5 patients, middle BA in 20 patients, and distal BA in 6 patients. Mean time to treatment was 334 min (95% CI 276-391 min). Procedure duration differed significantly ( p = 0.002) as follows: 97 min with SRT (95% CI 69-124 min) and 55 min with AT (95% CI 43-66 min). Recanalization (arterial occlusive lesion (AOL) 2/3) was achieved in 26 patients (79%). Complete recanalization (AOL 3) happened more often with AT (75% (95% CI 65-85%)) compared to SRT (46% (95% CI 32-60%)). Conversion rate 6% (two patients). Hemorrhages occurred in 12 (36%) patients, periprocedural complications in eight (three dissections, five embolizations to new territory) (no group difference). Ten patients (30%) had a favorable outcome (mRS ≤3) at discharge; mortality rate was 24% (eight deaths) (no group difference). Conclusion: In primarily embolic BAO, aspiration thrombectomy was faster, effective and not detrimental to outcome as compared to stentriever thrombectomy. Thus, it may be justified to use aspiration thrombectomy as first-line treatment in these patients. [ABSTRACT FROM AUTHOR]

Introduction: Treatment of complex anterior circulation aneurysms with flow diverters (FDs) has become common practice in neurovascular centers. However, this treatment method for posterior circulation aneurysms (PCAs) still remains controversial. Methods: Through searches for reports on the treatment of PCAs with FDs, we conducted a systematic review of the literature on its clinical efficacy and safety using random-effect binomial meta-analysis. Results: We included 14 studies, which reported on a total of 225 PCAs in 220 patients. Procedure-related good outcome rate was 79 % (95 % confidence interval (CI), 72-84), with significantly lower odds among patients with ruptured aneurysms and basilar artery aneurysms. Procedure-related mortality rate was 15 % (95 % CI 10-21), with significantly higher rates among patients with giant aneurysms and basilar artery aneurysms. The rate of complete aneurysm occlusion at 6-month digital subtraction angiography (DSA) was 84 %. Ischemic stroke rate was 11 %. Perforator infarction rate was 7 %. Postoperative subarachnoid hemorrhage (SAH) rate was 3 %. Intraparenchymal hemorrhage (IPH) rate was 4 %. Conclusions: Flow diverter treatment of PCAs is an effective method, which provides a high rate of complete occlusion at 6-month DSA. However, compared with anterior circulation aneurysms, patients with PCAs are at significantly higher risk of mortality, ischemic stroke and perforator infarction. Our findings indicate that, in most clinical centers, flow diverter treatment of PCAs should be conducted in carefully selected patients with poor natural history and no optimal treatment strategy. For ruptured and giant basilar artery aneurysms, there is still no good treatment option. [ABSTRACT FROM AUTHOR]

Introduction: Basilar artery (BA) perforator aneurysms may lead to severe subarachnoid hemorrhage (SAH). The acute management is uncertain. The anatomic approach is challenging both for coiling and clipping, and flow diverter stenting may be dangerous due to the required antiplatelet therapy. We report on our experiences in eight patients. Methods: We retrospectively analyzed eight patients with ruptured BA perforator aneurysm, including clinical characteristics, imaging data, treatment regimen, clinical course, and long-term outcome. Results: Patients presented with major SAH and World Federation of Neurosurgical Societies (WFNS) scores of I in three, II in two, and V in three cases. In four patients, the aneurysm was detected in the initial angiography, in four only in follow-up angiography. Five patients were treated conservatively and three patients had endovascular therapy. In the conservative group, the aneurysm spontaneously thrombosed in three cases. One patient suffered from a re-SAH and stayed permanently dependent due to an associated perforator stroke (modified Rankin Scale (mRS) 5). The remaining four patients recovered well (mRS 0 and 1 in two cases, each) including three patients also exhibiting perforator strokes. Regarding the endovascular group, one parent vessel was an angioma feeder and embolized with Onyx. The second aneurysm spontaneously thrombosed periinterventionally. The third patient underwent coiling. Two parent vessels were occluded postinterventionally, resulting in perforator strokes. Final mRS scores were 0, 2, and 2, respectively. Conclusion: Conservative management of ruptured BA aneurysms might be a first-line treatment option with common spontaneous aneurysm occlusion, low rate of re-SAH, and promising clinical outcome. [ABSTRACT FROM AUTHOR]

Introduction: The aim of the study is to assess the effect of shape, diameter, elongation and deviation criteria of basilar artery (BA), convergence angle and diameter variations of vertebral arteries, and concurrent chronic diseases on posterior circulation infarcts. Methods: Between January 2010 and May 2013, 186 patients who underwent brain and diffusion magnetic resonance imaging (MRI) with suspected cerebrovascular accident and were diagnosed with posterior circulation infarct and 120 infarct negative control subjects were included in this case-control retrospective study. Vertebral artery (VA) and BA diameter, right (R) and left (L) VA angles at the level of bifurcation, and BA elongation-deviation, and shape of BA were assessed in a total of 306 subjects. Ischemic lesions in the posterior circulation were classified according to their anatomical location and vascular perfusion areas. Results: No significant difference was noted between the control and patient groups with respect to BA diameter ( p = 0.676). The most effective risk factors for posterior circulation infarcts were as follows: BA elongation of 2 or 3, BA transverse location of 2 or 3, increase in left VA angle, and history of hypertension, hypercholesterolemia, and diabetes mellitus. Conclusion: Our results suggest that prominent elongation and deviation, C and J shape of BA, and increased L VA angle may be the predictors of at-risk patients in posterior circulation infarcts. Reporting marked morphological BA and VA variations detected at routine brain MRI will aid in selection of patients. Timely detection and treatment of at-risk patients may be life-saving. [ABSTRACT FROM AUTHOR]

Introduction: The objectives of this paper are to assess collateral blood flow in posterior circulation occlusion by MRI-based approaches (fluid-attenuated inversion recovery (FLAIR) vascular hyperintensities (FVHs), collateralization on dynamic 4D angiograms) and investigate its relation to ischemic lesion size and growth. Methods: In 28 patients with posterior cerebral artery (PCA) and 10 patients with basilar artery (BA) occlusion, MRI findings were analyzed, with emphasis on distal FVH and collateralization on dynamic 4D angiograms. Results: In PCA occlusion, distal FVH was observed in 18/29 (62.1 %), in BA occlusion, in 8/10 (80 %) cases. Collateralization on dynamic 4D angiograms was graded 1 in 8 (27.6 %) patients, 2 in 1 (3.4 %) patient, 3 in 12 (41.4 %) patients, and 4 in 8 (27.6 %) patients with PCA occlusion and 0 in 1 (10 %) patient, 2 in 3 (30 %) patients, 3 in 1 (10 %) patient, and 4 in 5 (50 %) patients with BA occlusion. FVH grade showed neither correlation with initial or follow-up diffusion-weighted image (DWI) lesion size nor DWI-perfusion-weighted imaging (PWI) mismatch ratio. Collateralization on dynamic 4D angiograms correlated inversely with initial DWI lesion size and moderately with the DWI-(PWI) mismatch ratio. The combination of distal FVH and collateralization grade on dynamic 4D angiograms correlated inversely with initial as well as follow-up DWI lesion size and highly with the DWI-PWI mismatch ratio. Conclusions: In posterior circulation occlusion, FVH is a frequent finding, but its prognostic value is limited. Dynamic 4D angiograms are advantageous to examine and graduate collateral blood flow. The combination of both parameters results in an improved characterization of collateral blood flow and might have prognostic relevance. [ABSTRACT FROM AUTHOR]

Introduction: In acute symptomatic vertebrobasilar artery stenosis, the use of mechanical recanalisation remains controversial. The complication rate of acute interventional recanalisation (aIR) has to be considered, as evidence from randomised trials is lacking. In a single centre retrospective case series, we here describe complications and outcome after aIR. Methods: We retrospectively assessed aIR in a tertiary care centre and included the following parameters: indication for aIR, national institute of health stroke scale (NIHSS) score on admission, recanalisation by thrombolysis in myocardial infarction score (TIMI) grades, post-interventional complications, mortality, NIHSS and modified Rankin scale at follow-up and rate of restenosis. Results: We identified 14 aIR (14 percutaneous transluminal angioplasty with or without stent implantation in 12 patients; 6/12 with thrombolysis; n = 6 vertebral artery, n = 8 basilar artery; 4 women, mean age 67 years). Mortality was 25 % (3/12) after 7 days and 42 % (5/12) after 12 months. In 12/14, interventions are complete (TIMI 3, 86 %), in 2/14, a partial recanalisation (TIMI 2, 14 %) was achieved. In one case, a peri-interventional fatal intracerebral haemorrhage occurred (1/12, 8 %). At late follow-up (mean 342 days), one re-occlusion (1/7, 14 %) and one recurrent stroke (1/12, 8 %) were observed. Conclusions: In our single centre series of vertebrobasilar aIR recanalisation rate was high. However, procedural safety and clinical outcome varied considerably. The results of aIR need to be assessed in multicentric registers to define the procedural risk and outcome in the clinical setting. [ABSTRACT FROM AUTHOR]

Introduction: Fenestrations of cerebral arteries are most common in the vertebrobasilar (VB) system, and magnetic resonance (MR) angiographic studies of these variations are sparse. Methods: We retrospectively reviewed MR angiographic images of 3,327 patients; images were obtained using two 1.5-T imagers and picked up fenestrations of the intracranial vertebral artery (VA), VB junction, and basilar artery (BA) for evaluation. Results: In 92 patients, we found 93 fenestrations (2.80%), which included 18 of the intracranial VA (0.54% prevalence), 6 of the VB junction (0.18%), and 69 of the BA (2.07%). Most VA fenestrations were large, and the posterior inferior cerebellar artery arose from the fenestrated segment in 10 patients (56%). Fenestrations of the VB junction were small and triangular. Sixty-five (94%) of the 69 BA fenestrations were located at the proximal segment and had small slit-like configurations. The anterior inferior cerebellar artery arose from the fenestrated segment in 27 patients (37%). We found 18 cerebral aneurysms in 16 (17%) of the 92 patients with fenestration but detected only one aneurysm at the fenestration. Conclusion: The overall prevalence of fenestrations of the intracranial VB system was 2.77%. We found associated cerebral aneurysms relatively frequently but rarely at the fenestration. [ABSTRACT FROM AUTHOR]

Introduction: We aimed to investigate the value of the hyperdense basilar artery (HBA) sign and of basilar artery (BA) attenuation measurements as predictors of basilar artery occlusion (BAO) on nonenhanced cranial CT (NECT). Methods: Forty-one consecutive patients with proven BAO in CT angiography, who had undergone NECT for initial evaluation (30 males, 11 females) were retrospectively included. Another 41 age-matched patients without BAO were included as a control group. The NECT scans of both groups were assessed by three independent blinded readers (staff, fellow, and resident) in a randomized reading order using a standardized semiquantitative questionnaire. Visual BA hyperdensity, including the presence of HBA sign (hyperdensity scores of 4 and 5/5), was assessed, quantitative BA attenuation was measured in a region of interest (ROI), and diagnosis of BAO was made before and after ROI measurements. For statistical analysis, multivariate mixed effects models, likelihood ratio tests, and receiver operating characteristics techniques were applied. Results: HBA sign had a relatively low sensitivity (60.98-65.85%), specificity (70.73-90.24%), and accuracy (65.85-75.61%) for the presence/absence of BAO on NECT. Optimal cut-off points were 40-42 HU (sensitivity, 68.29-78.05%; specificity, 75.61-82.93%; accuracy, 74.39-80.49%). Conclusion: In basilar artery occlusion, quantitative measurement of BA attenuation can slightly improve the diagnostic predictiveness of NECT. However, even with optimal cut-off values, the sensitivity is too low to serve as the sole diagnostic decision-making tool. [ABSTRACT FROM AUTHOR]

A 4-year-old girl suffered intraventricular and subarachnoid hemorrhage during endoscopic third ventriculostomy. Cerebral angiography revealed a traumatic basilar aneurysm secondary to basilar artery injury. The aneurysm was treated with selective endovascular embolization using Guglielmi detachable coils. We review some therapeutic features of traumatic basilar aneurysms after endoscopic third ventriculostomy and describe the feasibility of endovascular selective therapy to manage these lesions successfully. [ABSTRACT FROM AUTHOR]

We compared the rates of recanalization cerebral infarct and hemorrhage between intra-arterial (IA) reteplase and intravenous (IV) alteplase thrombolysis in a canine model of basilar artery thrombosis. Thrombosis was induced by injecting a clot in the basilar artery of 13 anesthetized dogs via superselective catheterization. The animals were randomized in a blinded fashion. 2 h after clot injection and verification of arterial occlusion, to receive IV alteplase 0.9 mg. kg over 60 min and IA placebo, or IA reteplase 0.09 units kg over 20 min, equivalent lo one-half the alteplase dose, and IV placebo. Recanalization was studied for 6 h after treatment with serial angiography; the images were later graded in a blinded fashion. Blinded interpretation of postmortem MRI was performed to assess the presence of brain infarcts and or hemorrhage. At 3 h after initiation of treatment, partial or complete recanalization was observed in one of six dogs in the IV alteplase group and in five of seven in the IA reteplase group (P =0.08). At 6 h. no significant difference in partial or complete recanalization was observed between the groups (two of six vs. five of seven; P =0.20). Postmortem MRI revealed infarcts in four of six animals treated with IV alteplase and three of seven treated with IA reteplase (P =0.4). Intracerebral hemorrhage was more common in the IV alteplase group (four of six vs. none of seven: P =0.02). This study thus suggests that IA thrombolysis affords a recanalization rate similar to that of IV thrombolysis, but with a lower rate of intracerebral hemorrhage. [ABSTRACT FROM AUTHOR]

Intra-arterial thrombolysis (IAT) is the only treatment that has demonstrated benefit in patients with acute basilar artery occlusions (ABAO). IAT may be difficult to perform when access to the occluded basilar artery (BA) is prevented by pathology of the vertebral arteries (VA). We report on two patients with ABAO due to embolism from the dominating VA. Catheter navigation through the occluded VA and thromboaspiration enabled access to the BA. Thromboaspiration alone or in addition to IAT resulted in a complete recanalization of the BA and a favorable clinical outcome. A stent was deployed at the site of the stenosis in the VA either prior to or immediately after BA recanalization. [ABSTRACT FROM AUTHOR]

Endovascular coil occlusion of fusiform intracranial aneurysms without sacrifice of the parent artery can be technically challenging. Bridging of wide aneurysm necks with stents is common practice for side-wall aneurysms but is less frequently used for bifurcation aneurysms. We describe the technical aspects of the successful coil occlusion of a fusiform aneurysm of the upper basilar trunk, with preservation of the parent vessel. The procedure comprised the following steps: (a) stenting of the left V1- and proximal V2 segments; (b) simultaneous deployment of two Neuroform stents from both P1 segments down to the basilar artery (“kissing” stents) (c) using a TriSpan device to hold (d) three-dimensional electrolytically detachable coils in place and (e) filling the aneurysmal lumen mainly with fibered electrolytically detachable coils; and finally (f) cutting the extracorporeal part of both microguidewires below the skin level in both groins, leaving the microguidewires as they were used for the deployment of the stents in place, thus reaching from both P2 segments down to the basilar artery and further proximally. [ABSTRACT FROM AUTHOR]

We report two instructive cases of ruptured dissecting aneurysm of the basilar artery. Although stent-assisted endovascular treatment was successful, recurrent bleeding occurred 4 h after the procedure in one patient, and the other's basilar artery occluded 6 days after the procedure. These cases suggest that the high porosity of currently available stents may be insufficient to induce intraluminal thrombosis and merely stenting may fail to prevent bleeding, while post- operative anticoagulation alone may be inadequate to prevent occlusion of the stented vessel. [ABSTRACT FROM AUTHOR]

We reviewed all patients over a 3-year period with documented aneurysms of the posterior cerebral circulation, and re-examined the angiograms of 103 patients. There were 9 cases of fenestration of the basilar artery, all associated with aneurysms of the basilar artery. In 6, the aneurysm arose at the site of the fenestration. We believe that the presence of a fenestration predisposes to aneurysm formation, due to the combination of the resulting alteration in flow characteristics and the presence of a defect in the media of the vessel. [ABSTRACT FROM AUTHOR]

We report three patients with persistent trigeminal arteries, in all of whom the proximal basilar artery was hypoplastic. We draw attention to this common observation, which should not be mistaken for acquired narrowing. [ABSTRACT FROM AUTHOR]

The basilar artery is the only large artery in which two flows merge, and this is reflected in the flow downstream. We report quantitative flow - velocity measurements with a phase-based MR technique, i.e. the Fourier velocity encoding method, in the basilar artery of a volunteer. To our knowledge, this has not previously been performed successfully. A comparison is made with the results of flow velocity measurements in the basilar artery with transcranial Doppler ultrasonography; the techniques agreed very well. Although Doppler ultrasonography is still most widely used, no information on the flow rate and the flow velocity distribution in the basilar artery can be provided. MR flow measurement techniques appear promising when detailed information on the flow velocity distribution and flow rate is needed. [ABSTRACT FROM AUTHOR]

Two patients with complex aneurysms of the vertebrobasilar system were treated using platinum coils. During these sessions, 22 coils were placed in a basilar tip aneurysm in a 48-year-old woman. Almost total occlusion of the lumen was achieved, excepted in the area from which the right posterior cerebral artery arose. A large fusiform vertebral artery aneurysm in a 6-year-old boy was treated using 16 coils, which partially occluded the lumen at initial embolization. Follow-up angiography 2 weeks later revealed almost complete occlusion of the lumen with preservation of the vertebral artery. Our experience indicates that coil embolization of complex intracranial aneurysms is an acceptable treatment alternative to surgery or to a detachable balloon. [ABSTRACT FROM AUTHOR]

Magnetic resonance (MR) images of nine patients with intracranial vertebral artery occlusion (five proved, four presumed) have been reviewed. In two of nine, both vertebral arteries were occluded and in five of the nine, the basilar artery was also blocked. All occluded arteries showed absence of flow void and were clearly demonstrated as mildly hypo-∼mildly hyperintense structures to brainstem parenchyma on the T1-weighted images. In two of five patients with basilar artery occlusion, retrograde filling of the distal basilar artery was detected. Thus, MR imaging, in particular the T1-weighted image, is a pertinent diagnostic modality for evaluating intracranial vertebral artery occlusion. Angiography does not seem to be required for confirmation. [ABSTRACT FROM AUTHOR]

We evaluated six patients with vertebrobasilar dolichoectasia (VBD) comparing clinical presentation with magnetic resonance (MR) and computed tomography (CT) imaging. MR diagnosed the condition as well as CT in all cases, but proved superior to CT in delineating the anatomical relationship of the vessels to the neural structures. MR proved especially useful in cases of VBD-associated hydrocephalus and posterior fossa masses. A coexisting tumor was diagnosed by MR in one case. [ABSTRACT FROM AUTHOR]

Sixteen patients having infarction caused by circulatory disturbance at the top of the basilar artery, that is to say, the 'top of the basilar' syndrome, were studied, the diagnosis having been made by computerized tomography. Infarcts were widely distributed in each patient between the thalamus, midbrain, pons, cerebellum, and occipital lobe. Both thalami were involved in 7 cases. When the thalamus was involved bilaterally, the low density areas were symmetrical in size and localization. Angiography revealed that stenosis or occlusion lay within a circle 2 cm in diameter surrounding the five-forked junction at the top of the basilar artery in 84.6%. Recanalization of the occluded artery occurred in 61.5%, suggesting that embolism played an important role in appearance of this syndrome. [ABSTRACT FROM AUTHOR]

Five angiographically confirmed cases of ectasia of the basilar artery are described. Three patients presented with the classical combination of lower cranial nerve, bulbar, cerebellar and long tract signs and dementia, one as obstructive hydrocephalus with papilloedema, and the fifth with symptoms of chiasmal compression. All were above middle age and hypertensive. CT scanning demonstrated a partially calcified, tubular, enhancing prepontine and suprasellar mass in every case. Ventricular enlargement and cerebral parenchymal abnormalities were also present. These appearances are sufficiently characteristic to make invasive radiological investigation unnecessary. [ABSTRACT FROM AUTHOR]