Endovascular Versus Medical Therapy in Posterior Cerebral Artery Stroke: Role of Baseline NIHSS Score and Occlusion Site.

BACKGROUND: Acute ischemic stroke with isolated posterior cerebral artery occlusion (iPCAO) lacks management evidence from randomized trials. We aimed to evaluate whether the association between endovascular treatment (EVT) and outcomes in iPCAO acute ischemic stroke is modified by initial stroke severity (baseline National Institutes of Health Stroke Scale [NIHSS]) and arterial occlusion site. METHODS: Based on the multicenter, retrospective, case-control study of consecutive iPCAO acute ischemic stroke patients (PLATO study [Posterior Cerebral Artery Occlusion Stroke]), we assessed the heterogeneity of EVT outcomes compared with medical management (MM) for iPCAO, according to baseline NIHSS score (≤6 versus >6) and occlusion site (P1 versus P2), using multivariable regression modeling with interaction terms. The primary outcome was the favorable shift of 3-month modified Rankin Scale (mRS). Secondary outcomes included excellent outcome (mRS score 0-1), functional independence (mRS score 0-2), symptomatic intracranial hemorrhage, and mortality. RESULTS: From 1344 patients assessed for eligibility, 1059 were included (median age, 74 years; 43.7% women; 41.3% had intravenous thrombolysis): 364 receiving EVT and 695 receiving MM. Baseline stroke severity did not modify the association of EVT with 3-month mRS distribution (Pinteraction=0.312) but did with functional independence (Pinteraction=0.010), with a similar trend on excellent outcome (Pinteraction=0.069). EVT was associated with more favorable outcomes than MM in patients with baseline NIHSS score >6 (mRS score 0-1, 30.6% versus 17.7%; adjusted odds ratio [aOR], 2.01 [95% CI, 1.22-3.31]; mRS score 0 to 2, 46.1% versus 31.9%; aOR, 1.64 [95% CI, 1.08-2.51]) but not in those with NIHSS score ≤6 (mRS score 0-1, 43.8% versus 46.3%; aOR, 0.90 [95% CI, 0.49-1.64]; mRS score 0-2, 65.3% versus 74.3%; aOR, 0.55 [95% CI, 0.30-1.0]). EVT was associated with more symptomatic intracranial hemorrhage regardless of baseline NIHSS score (Pinteraction=0.467), while the mortality increase was more pronounced in patients with NIHSS score ≤6 (Pinteraction=0.044; NIHSS score ≤6: aOR, 7.95 [95% CI, 3.11-20.28]; NIHSS score >6: aOR, 1.98 [95% CI, 1.08-3.65]). Arterial occlusion site did not modify the association of EVT with outcomes compared with MM. CONCLUSIONS: Baseline clinical stroke severity, rather than the occlusion site, may be an important modifier of the association between EVT and outcomes in iPCAO. Only severely affected patients with iPCAO (NIHSS score >6) had more favorable disability outcomes with EVT than MM, despite increased mortality and symptomatic intracranial hemorrhage.

Outcomes of Bridging Intravenous Thrombolysis Versus Endovascular Therapy Alone in Late-Window Acute Ischemic Stroke.

BACKGROUND: Studies comparing bridging intravenous thrombolysis (IVT) with direct endovascular therapy (EVT) in patients with acute ischemic stroke who present late are limited. We aimed to compare the clinical outcomes and safety of bridging IVT in patients with acute ischemic stroke due to anterior circulation large vessel occlusion who underwent EVT 6 to 24 hours after time last known well. METHODS: We enrolled patients with anterior circulation large vessel occlusion stroke and a National Institutes of Health Stroke Scale score of ≥6 from 20 centers across 10 countries in the multicenter retrospective CLEAR study (CT for Late Endovascular Reperfusion) between January 2014 and May 2022. We used inverse probability of treatment weighting modeling adjusted for clinical and imaging confounders to compare functional outcomes, reperfusion success, symptomatic intracranial hemorrhage, and mortality between EVT patients with and without prior IVT. RESULTS: Of 5098 patients screened for eligibility, we included 2749 patients, of whom 549 received bridging IVT before EVT. The timing of IVT was not recorded. Witnessed stroke onset and transfer rates were higher in the bridging IVT group (25% versus 12% and 77% versus 55%, respectively, P value for both <0.0001), and time intervals between stroke onset and treatment were shorter (time last known well-start of EVT median 560 minutes [interquartile range, 432-791] versus 724 minutes [interquartile range, 544-912]; P<0.0001). After adjustment for confounders, there was no difference in functional outcome at 3 months (adjusted common odds ratio for modified Rankin Scale shift, 1.03 [95% CI, 0.89-1.19]; P=0.72) or successful reperfusion (adjusted odds ratio, 1.19 [95% CI, 0.81-1.75]; P=0.39). There were no safety concerns associated with bridging IVT versus direct EVT (symptomatic intracranial hemorrhage: adjusted odds ratio, 0.75 [95% CI, 0.38-1.48]; P=0.40; mortality: adjusted odds ratio, 1.14 [95% CI, 0.89-1.46]; P=0.31). Results were unchanged when the analysis was limited to patients who received IVT >6 hours after last known well. CONCLUSIONS: In patients with an anterior circulation large vessel occlusion stroke who underwent EVT 6 to 24 hours from last known well, bridging IVT was not associated with a difference in outcomes compared with direct EVT. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT04096248.

Sex Differences in Outcomes of Late-Window Endovascular Stroke Therapy.

BACKGROUND: The association between sex and outcome after endovascular thrombectomy of acute ischemic stroke is unclear. The aim of this study was to compare the clinical and safety outcomes between men and women treated with endovascular thrombectomy in the late 6-to-24-hour window period. METHODS: This multicenter, retrospective observational cohort study included consecutive patients who underwent endovascular thrombectomy of anterior circulation stroke in the late window from 66 clinical sites in 10 countries from January 2014 to May 2022. The primary outcome was the 90-day ordinal modified Rankin Scale score. Secondary outcomes included 90-day functional independence (FI), return of Rankin (RoR) to prestroke baseline, FI or RoR, symptomatic intracranial hemorrhage, and mortality. Multivariable and inverse probability of treatment weighting methods were used. We explored the interaction of sex with baseline characteristics on the outcomes ordinal modified Rankin Scale and FI or RoR. RESULTS: Of 1932 patients, 1055 were women and 877 were men. Women were older (77 versus 69 years), had higher rates of atrial fibrillation, hypertension, and greater prestroke disability, but there was no difference in baseline National Institutes of Health Stroke Scale score. Inverse probability of treatment weighting analysis showed no difference between women and men in ordinal modified Rankin Scale (odds ratio, 0.98 [95% CI, 0.79-1.21]), FI or RoR (odds ratio, 0.98 [95% CI, 0.78-1.22]), severe disability or mortality (odds ratio, 0.99 [95% CI, 0.80-1.23]). The multivariable analysis of the above end points was concordant. There were no interactions between baseline characteristics and sex on the outcomes of ordinal modified Rankin Scale and FI or RoR. CONCLUSIONS: In late presenting patients with anterior circulation stroke treated with endovascular thrombectomy in the 6 to 24-hour window, there was no difference in clinical or safety outcomes between men and women.

Endovascular thrombectomy for acute ischaemic stroke with established large infarct: multicentre, open-label, randomised trial.

BACKGROUND: Recent evidence suggests a beneficial effect of endovascular thrombectomy in acute ischaemic stroke with large infarct; however, previous trials have relied on multimodal brain imaging, whereas non-contrast CT is mostly used in clinical practice. METHODS: In a prospective multicentre, open-label, randomised trial, patients with acute ischaemic stroke due to large vessel occlusion in the anterior circulation and a large established infarct indicated by an Alberta Stroke Program Early Computed Tomographic Score (ASPECTS) of 3-5 were randomly assigned using a central, web-based system (using a 1:1 ratio) to receive either endovascular thrombectomy with medical treatment or medical treatment (ie, standard of care) alone up to 12 h from stroke onset. The study was conducted in 40 hospitals in Europe and one site in Canada. The primary outcome was functional outcome across the entire range of the modified Rankin Scale at 90 days, assessed by investigators masked to treatment assignment. The primary analysis was done in the intention-to-treat population. Safety endpoints included mortality and rates of symptomatic intracranial haemorrhage and were analysed in the safety population, which included all patients based on the treatment they received. This trial is registered with ClinicalTrials.gov, NCT03094715. FINDINGS: From July 17, 2018, to Feb 21, 2023, 253 patients were randomly assigned, with 125 patients assigned to endovascular thrombectomy and 128 to medical treatment alone. The trial was stopped early for efficacy after the first pre-planned interim analysis. At 90 days, endovascular thrombectomy was associated with a shift in the distribution of scores on the modified Rankin Scale towards better outcome (adjusted common OR 2·58 [95% CI 1·60-4·15]; p=0·0001) and with lower mortality (hazard ratio 0·67 [95% CI 0·46-0·98]; p=0·038). Symptomatic intracranial haemorrhage occurred in seven (6%) patients with thrombectomy and in six (5%) with medical treatment alone. INTERPRETATION: Endovascular thrombectomy was associated with improved functional outcome and lower mortality in patients with acute ischaemic stroke from large vessel occlusion with established large infarct in a setting using non-contrast CT as the predominant imaging modality for patient selection. FUNDING: EU Horizon 2020.

Cortical atrophy on baseline computed tomography imaging predicts clinical outcome in patients undergoing endovascular treatment for acute ischemic stroke.

OBJECTIVE: Multiple variables beyond the extent of recanalization can impact the clinical outcome after acute ischemic stroke due to large vessel occlusions. Here, we assessed the influence of small vessel disease and cortical atrophy on clinical outcome using native cranial computed tomography (NCCT) in a large single-center cohort. METHODS: A total of 1103 consecutive patients who underwent endovascular treatment (EVT) due to occlusion of the middle cerebral artery territory were included. NCCT data were visually assessed for established markers of age-related white matter changes (ARWMC) and brain atrophy. All images were evaluated separately by two readers to assess the inter-observer variability. Regression and machine learning models were built to determine the predictive relevance of ARWMC and atrophy in the presence of important baseline clinical and imaging metrics. RESULTS: Patients with favorable outcome presented lower values for all measured metrics of pre-existing brain deterioration (p < 0.001). Both ARWMC (p < 0.05) and cortical atrophy (p < 0.001) were independent predictors of clinical outcome at 90 days when controlled for confounders in both regression analyses and led to a minor improvement of prediction accuracy in machine learning models (p < 0.001), with atrophy among the top-5 predictors. CONCLUSION: NCCT-based cortical atrophy and ARWMC scores on NCCT were strong and independent predictors of clinical outcome after EVT. CLINICAL RELEVANCE STATEMENT: Visual assessment of cortical atrophy and age-related white matter changes on CT could improve the prediction of clinical outcome after thrombectomy in machine learning models which may be integrated into existing clinical routines and facilitate patient selection. KEY POINTS: • Cortical atrophy and age-related white matter changes were quantified using CT-based visual scores. • Atrophy and age-related white matter change scores independently predicted clinical outcome after mechanical thrombectomy and improved machine learning-based prediction models. • Both scores could easily be integrated into existing clinical routines and prediction models.

Dual Layer vs Single Layer Woven EndoBridge Device in the Treatment of Intracranial Aneurysms: A Propensity Score-Matched Analysis.

BACKGROUND: The Woven EndoBridge (WEB) devices have been used for treating wide neck bifurcation aneurysms (WNBAs) with several generational enhancements to improve clinical outcomes. The original device dual-layer (WEB DL) was replaced by a single-layer (WEB SL) device in 2013. This study aimed to compare the effectiveness and safety of these devices in managing intracranial aneurysms. METHODS: A multicenter cohort study was conducted, and data from 1,289 patients with intracranial aneurysms treated with either the WEB SL or WEB DL devices were retrospectively analyzed. Propensity score matching was utilized to balance the baseline characteristics between the two groups. Outcomes assessed included immediate occlusion rate, complete occlusion at last follow-up, retreatment rate, device compaction, and aneurysmal rupture. RESULTS: Before propensity score matching, patients treated with the WEB SL had a significantly higher rate of complete occlusion at the last follow-up and a lower rate of retreatment. After matching, there was no significant difference in immediate occlusion rate, retreatment rate, or device compaction between the WEB SL and DL groups. However, the SL group maintained a higher rate of complete occlusion at the final follow-up. Regression analysis showed that SL was associated with higher rates of complete occlusion (OR: 0.19; CI: 0.04 to 0.8, p = 0.029) and lower rates of retreatment (OR: 0.12; CI: 0 to 4.12, p = 0.23). CONCLUSION: The WEB SL and DL devices demonstrated similar performances in immediate occlusion rates and retreatment requirements for intracranial aneurysms. The SL device showed a higher rate of complete occlusion at the final follow-up.

Effect of Individualized Versus Standardized Blood Pressure Management During Endovascular Stroke Treatment on Clinical Outcome: A Randomized Clinical Trial.

BACKGROUND: Optimal blood pressure (BP) management during endovascular stroke treatment is not well established. We studied whether an individualized approach for managing BP during endovascular stroke treatment gives a better clinical outcome than an approach with standardized systolic BP targets. METHODS: The INDIVIDUATE study (Individualized Blood Pressure Management During Endovascular Treatment of Acute Ischemic Stroke Under Procedural Sedation) is a randomized clinical trial with a prospective randomized open blinded end point (PROBE) design. Patients were recruited between October 1, 2020 and July 7, 2022 at a single center at a tertiary care university hospital. Patients were eligible, when they were suffering from acute ischemic stroke of the anterior circulation with occlusions of the internal carotid artery and middle cerebral artery and a National Institutes of Health Stroke Scale score of ≥8 receiving endovascular stroke treatment in procedural sedation. The intervention consists of an individualized BP management strategy, where preinterventional baseline systolic BP (SBP) values are used as intraprocedural BP targets. As a control, the standard treatment aims to maintain the intraprocedural SBP between 140 and 180 mm Hg. The main prespecified outcome is the proportion of favorable functional outcomes 90 days after stroke, defined as a modified Rankin Scale score of 0 to 2. RESULTS: Two hundred fifty patients were enrolled and included in the analysis, mean (SD) age was 77 (12) years, 142 (57%) patients were women, and mean (SD) National Institutes of Health Stroke Scale score on admission was 17 (5.2). In all, 123 (49%) patients were treated with individualized and 127 (51%) with standard BP management. Mean (SD) intraprocedural SBP was similar in the individualized versus standard BP management group (157 [19] versus 154 [18] mm Hg; P=0.16). The rate of favorable functional outcome after 3 months was not significantly different between the individualized versus the standard BP management group (25% versus 24%; adjusted odds ratio, 0.81 [95% CI, 0.41-1.61]; P=0.56). CONCLUSIONS: Among patients treated with endovascular stroke treatment due to an acute ischemic stroke of the anterior circulation, no significant difference was seen between the individualized BP management strategy, where intraprocedural SBP was targeted to baseline values, and the standardized regimen of targeting SBP between 140 and 180 mm Hg. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT04578288.

Thrombectomy versus Medical Management for Isolated Anterior Cerebral Artery Stroke: An International Multicenter Registry Study.

Background Evidence supporting a potential benefit of thrombectomy for distal medium vessel occlusions (DMVOs) of the anterior cerebral artery (ACA) is, to the knowledge of the authors, unknown. Purpose To compare the clinical and safety outcomes between mechanical thrombectomy (MT) and best medical treatment (BMT) with or without intravenous thrombolysis for primary isolated ACA DMVOs. Materials and Methods Treatment for Primary Medium Vessel Occlusion Stroke, or TOPMOST, is an international, retrospective, multicenter, observational registry of patients treated for DMVO in daily practice. Patients treated with thrombectomy or BMT alone for primary ACA DMVO distal to the A1 segment between January 2013 and October 2021 were analyzed and compared by one-to-one propensity score matching (PSM). Early outcome was measured by the median improvement of National Institutes of Health Stroke Scale (NIHSS) scores at 24 hours. Favorable functional outcome was defined as modified Rankin scale scores of 0-2 at 90 days. Safety was assessed by the occurrence of symptomatic intracerebral hemorrhage and mortality. Results Of 154 patients (median age, 77 years; quartile 1 [Q1] to quartile 3 [Q3], 66-84 years; 80 men; 94 patients with MT; 60 patients with BMT) who met the inclusion criteria, 110 patients (median age, 76 years; Q1-Q3, 67-83 years; 50 men; 55 patients with MT; 55 patients with BMT) were matched. DMVOs were in A2 (82 patients; 53%), A3 (69 patients; 45%), and A3 (three patients; 2%). After PSM, the median 24-hour NIHSS point decrease was -2 (Q1-Q3, -4 to 0) in the thrombectomy and -1 (Q1-Q3, -4 to 1.25) in the BMT cohort (P = .52). Favorable functional outcome (MT vs BMT, 18 of 37 [49%] vs 19 of 39 [49%], respectively; P = .99) and mortality (MT vs BMT, eight of 37 [22%] vs 12 of 39 [31%], respectively; P = .36) were similar in both groups. Symptomatic intracranial hemorrhage occurred in three (2%) of 154 patients. Conclusion Thrombectomy appears to be a safe and technically feasible treatment option for primary isolated anterior cerebral artery occlusions in the A2 and A3 segment with clinical outcomes similar to best medical treatment with and without intravenous thrombolysis. © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Zhu and Wang in this issue.

Metal artifacts and artifact reduction of neurovascular coils in photon-counting detector CT versus energy-integrating detector CT - in vitro comparison of a standard brain imaging protocol.

OBJECTIVES: Photon-counting detector computed tomography (PCD-CT) is a promising new technique for CT imaging. The aim of the present study was the in vitro comparison of coil-related artifacts in PCD-CT and conventional energy-integrating detector CT (EID-CT) using a comparable standard brain imaging protocol before and after metal artifact reduction (MAR). METHODS: A nidus-shaped rubber latex, resembling an aneurysm of the cerebral arteries, was filled with neurovascular platinum coils and inserted into a brain imaging phantom. Image acquisition and reconstruction were repeatedly performed for PCD-CT and EID-CT (n = 10, respectively) using a standard brain imaging protocol. Moreover, linear interpolation MAR was performed for PCD-CT and EID-CT images. The degree of artifacts was analyzed quantitatively (standard deviation in a donut-shaped region of interest) and qualitatively (5-point scale analysis). RESULTS: Quantitative and qualitative analysis demonstrated a lower degree of metal artifacts in the EID-CT images compared to the total-energy PCD-CT images (e.g., 82.99 ± 7.89 Hounsfield units (HU) versus 90.35 ± 6.28 HU; p < 0.001) with no qualitative difference between the high-energy bin PCD-CT images and the EID-CT images (4.18 ± 0.37 and 3.70 ± 0.64; p = 0.575). After MAR, artifacts were more profoundly reduced in the PCD-CT images compared to the EID-CT images in both analyses (e.g., 2.35 ± 0.43 and 3.18 ± 0.34; p < 0.001). CONCLUSION: PCD-CT in combination with MAR have the potential to provide an improved option for reduction of coil-related artifacts in cerebral imaging in this in vitro study. KEY POINTS: • Photon-counting detector CT produces more artifacts compared to energy-integrating detector CT without metal artifact reduction in cerebral in vitro imaging after neurovascular coil-embolization. • Spectral information of PCD-CT provides the potential for new post-processing techniques, since the coil-related artifacts were lower in PCD-CT images compared to EID-CT images after linear interpolation metal artifact reduction in this in vitro study.

Sclerotherapy of Venous Malformations Using Polidocanol: Effectiveness, Safety, and Predictors of Outcomes and Adverse Events.

PURPOSE: To assess the effectiveness, safety, and predictors of outcomes and adverse events for percutaneous sclerotherapy using polidocanol for the treatment of venous malformations (VMs). METHODS: A retrospective single-center analysis was performed, including patients with VMs who were treated with sclerotherapy using polidocanol between January 2011 and November 2021 at a tertiary center. Demographic characteristics, clinical data, and radiologic features were analyzed, and the influence of patient- and VM-related factors on the subjective clinical outcome and adverse events were investigated using a multivariate logistic regression analysis. RESULTS: In total, 167 patients who received 325 treatment sessions were included in this study. Overall symptom improvement was observed in 67.5%, stable symptoms were observed in 25.0%, and worsening was reported in 7.5% (clinical follow-up, 1.04 ± 1.67 years). The total adverse event rate was 10.2%, with an overall rate of 4.2% for permanent adverse events within the cohort. In multivariate analysis, the clinical outcome was worse in children (P = .01; 57.1% symptom improvement in children [age, <18 years] and 79.7% in adults), and adverse events were more frequently observed after the treatment of VMs located at the extremities (P < .01; 8.4% for VMs of the extremities and 1.2% for VMs in other locations). CONCLUSIONS: Sclerotherapy using polidocanol can be an effective treatment option for VMs with an acceptable safety profile. However, it can be less effective in children, and adverse events can be more frequently expected for VMs of the extremities.

Effect of intra-arterial nimodipine on iatrogenic vasospasms during endovascular stroke treatment - angiographic resolution and infarct growth in follow-up imaging.

PURPOSE: The treatment of vasospasms during endovascular stroke treatment (EST) with intra-arterial nimodipine (NM) is routinely performed. However, the efficacy of resolving iatrogenic vasospasms during the angiographic intervention and the infarct development in follow-up imaging after EST has not been studied yet. METHODS: Retrospective single-center analysis of patients receiving EST for anterior circulation vessel occlusion between 01/2015 and 12/2021. The primary endpoint was ASPECTS in follow-up imaging. Secondary endpoints were the clinical outcome (combined endpoint NIHSS 24 h after EST and difference between modified Rankin Scale (mRS) before stroke and at discharge (delta mRS)) and intracranial hemorrhage (ICH) in follow-up imaging. Patients with vasospasms receiving NM (NM+) or not (NM-) were compared in univariate analysis. RESULTS: Vasospasms occurred in 79/1283 patients (6.2%), who consecutively received intra-arterial NM during EST. The targeted vasospasm angiographically resolved in 84% (66/79) under NM therapy. ASPECTS was lower in follow-up imaging after vasospasms and NM-treatment (NM - 7 (6-9), NM + 6 (4.5-8), p = 0.013) and the clinical outcome was worse (NIHSS 24 h after EST was higher in patients treated with NM (median, IQR; NM+: 14, 5-21 vs. NM-: 9, 3-18; p = 0.004), delta-mRS was higher in the NM + group (median, IQR; NM+: 3, 1-4 vs. NM-: 2, 1-2; p = 0.011)). Any ICH (NM+: 27/79, 34.2% vs. NM-: 356/1204, 29.6%; p = 0.386) and symptomatic ICH (NM+: 2/79, 2.5% vs. NM-: 21/1204, 1.7%; p = 0.609) was equally distributed between groups. CONCLUSION: Intra-arterial nimodipine during EST resolves iatrogenic vasospasms efficiently during EST without increasing intracranial hemorrhage rates. However, patients with vasospasms and NM treatment show higher infarct growth resulting in lower ASPECTS in follow-up imaging.

Diagnostic imaging strategies of acute intracerebral hemorrhage in European academic hospitals-a decision-making analysis.

PURPOSE: To evaluate and compare which factors are relevant to the diagnostic decision-making and imaging workup of intracerebral hemorrhages in large, specialized European centers. METHODS: Expert neuroradiologists from ten large, specialized centers (where endovascular stroke treatment is routinely performed) in nine European countries were selected in cooperation with the European Society of Neuroradiology (ESNR). The experts were asked to describe how and when they would investigate specific causes in a patient who presented with an acute, atraumatic, intracerebral hemorrhage for two given locations: (1) basal ganglia, thalamus, pons or cerebellum; (2) lobar hemorrhage. Answers were collected, and decision trees were compared. RESULTS: Criteria that were considered relevant for decision-making reflect recommendations from current guidelines and were similar in all participating centers. CT Angiography or MR angiography was considered essential by the majority of centers regardless of other factors. Imaging in clinical practice tended to surpass guideline recommendations and was heterogeneous among different centers, e.g., in a scenario suggestive of typical hypertensive hemorrhage, recommendations ranged from no further follow-up imaging to CT angiography and MR angiography. In no case was a consensus above 60% achieved. CONCLUSION: In European clinical practices, existing guidelines for diagnostic imaging strategies in ICH evaluation are followed as a basis but in most cases, additional imaging investigation is undertaken. Significant differences in imaging workup were observed among the centers. Results suggest a high level of awareness and caution regarding potentially underlying pathology other than hypertensive disease.

Pressure cooker technique in cerebral AVMs and DAVFs: different treatment strategies.

BACKGROUND: The pressure cooker technique (PCT) was developed to enable safer and more extensive embolization of hypervascular lesions by simultaneously minimizing backflow of liquid embolic materials and thus reduce the risk of non-target embolization of adjacent healthy vessels. We report our experience in applying the PCT to cerebral arteriovenous malformations (AVMs) and dural arteriovenous fistulas (DAVFs) and additionally suggest our technical adjustments. METHODS: We retrospectively reviewed all patients suffering from AVMs or DAVFs that were treated with the PCT between 2018 and 2020 in two university hospitals. The endpoints of the study were clinical safety and the technical efficacy. The endpoints of the study were clinical safety and the technical efficacy. Clinical safety was the absence of death, major or minor symptomatic stroke, TIA and procedure-related intracranial bleeding (SAH) in the peri-procedural period until dismission. Good clinical outcome was defined as no deterioration of the modified Rankin Scale (mRS) score (comparing the pre- and post-procedural mRS evaluated by a trained neurologist at admission and dismission). The technical efficacy was considered as the complete embolization occlusion of the target vessels of the lesion documented on the final control angiogram. Long-term follow-up evaluation was not intended for this study as it was not available for all patients. RESULTS: Fifteen consecutive patients (6 women; mean age 55 y; range 20-82 y) with seven AVMs and eight DAVFs met the inclusion criteria. The primary clinical safety end point was obtained in all cases as no intraprocedural complications were encountered. All patients had a good clinical outcome with no difference between the pre- and post-mRS scores. The primary efficacy end point was reached in all cases. CONCLUSION: The PCT is a safe and effective technique in the treatment of cerebral AVMs and DAVFs. Adding an easy and fast step to the procedure, namely the injection of contrast media to test the complete obstruction by the plug, the risk of reflux seems to additionally be reduced.

Aspiration Versus Stent Retriever Thrombectomy for Distal, Medium Vessel Occlusion Stroke in the Posterior Circulation: A Subanalysis of the TOPMOST Study.

BACKGROUND: The optimal endovascular strategy for reperfusing distal medium-vessel occlusions (DMVO) remains unknown. This study evaluates angiographic and clinical outcomes of thrombectomy strategies in DMVO stroke of the posterior circulation. METHODS: TOPMOST (Treatment for Primary Medium Vessel Occlusion Stroke) is an international, retrospective, multicenter, observational registry of patients treated for DMVO between January 2014 and June 2020. This study analyzed endovascularly treated isolated primary DMVO of the posterior cerebral artery in the P2 and P3 segment. Technical feasibility was evaluated with the first-pass effect defined as a modified Thrombolysis in Cerebral Infarction Scale score of 3. Rates of early neurological improvement and functional modified Rankin Scale scores at 90 days were compared. Safety was assessed by the occurrence of symptomatic intracranial hemorrhage and intervention-related serious adverse events. RESULTS: A total of 141 patients met the inclusion criteria and were treated endovascularly for primary isolated DMVO in the P2 (84.4%, 119) or P3 segment (15.6%, 22) of the posterior cerebral artery. The median age was 75 (IQR, 62-81), and 45.4% (64) were female. The initial reperfusion strategy was aspiration only in 29% (41) and stent retriever in 71% (100), both achieving similar first-pass effect rates of 53.7% (22) and 44% (44; P=0.297), respectively. There were no significant differences in early neurological improvement (aspiration: 64.7% versus stent retriever: 52.2%; P=0.933) and modified Rankin Scale rates (modified Rankin Scale score 0-1, aspiration: 60.5% versus stent retriever 68.6%; P=0.4). In multivariable logistic regression analysis, the time from groin puncture to recanalization was associated with the first-pass effect (adjusted odds ratio, 0.97 [95% CI, 0.95-0.99]; P<0.001) that in turn was associated with early neurological improvement (aOR, 3.27 [95% CI, 1.16-9.21]; P<0.025). Symptomatic intracranial hemorrhage occurred in 2.8% (4) of all cases. CONCLUSIONS: Both first-pass aspiration and stent retriever thrombectomy for primary isolated posterior circulation DMVO seem to be safe and technically feasible leading to similar favorable rates of angiographic and clinical outcome.

Reperfusion Without Functional Independence in Late Presentation of Stroke With Large Vessel Occlusion.

BACKGROUND: Reperfusion without functional independence (RFI) is an undesired outcome following thrombectomy in acute ischemic stroke. The primary objective was to evaluate, in patients presenting with proximal anterior circulation occlusion stroke in the extended time window, whether selection with computed tomography (CT) perfusion or magnetic resonance imaging is associated with RFI, mortality, or symptomatic intracranial hemorrhage (sICH) compared with noncontrast CT selected patients. METHODS: The CLEAR study (CT for Late Endovascular Reperfusion) was a multicenter, retrospective cohort study of stroke patients undergoing thrombectomy in the extended time window. Inclusion criteria for this analysis were baseline National Institutes of Health Stroke Scale score ≥6, internal carotid artery, M1 or M2 segment occlusion, prestroke modified Rankin Scale score of 0 to 2, time-last-seen-well to treatment 6 to 24 hours, and successful reperfusion (modified Thrombolysis in Cerebral Infarction 2c-3). RESULTS: Of 2304 patients in the CLEAR study, 715 patients met inclusion criteria. Of these, 364 patients (50.9%) showed RFI (ie, mRS score of 3-6 at 90 days despite successful reperfusion), 37 patients (5.2%) suffered sICH, and 127 patients (17.8%) died within 90 days. Neither imaging selection modality for thrombectomy candidacy (noncontrast CT versus CT perfusion versus magnetic resonance imaging) was associated with RFI, sICH, or mortality. Older age, higher baseline National Institutes of Health Stroke Scale, higher prestroke disability, transfer to a comprehensive stroke center, and a longer interval to puncture were associated with RFI. The presence of M2 occlusion and higher baseline Alberta Stroke Program Early CT Score were inversely associated with RFI. Hypertension was associated with sICH. CONCLUSIONS: RFI is a frequent phenomenon in the extended time window. Neither magnetic resonance imaging nor CT perfusion selection for mechanical thrombectomy was associated with RFI, sICH, and mortality compared to noncontrast CT selection alone. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT04096248.

Multicenter Study for the Treatment of Sidewall versus Bifurcation Intracranial Aneurysms with Use of Woven EndoBridge (WEB).

Background The Woven EndoBridge (WEB) device was explicitly designed for wide-neck intracranial bifurcation aneurysms. Small-scale reports have evaluated the off-label use of WEB devices for the treatment of sidewall aneurysms, with promising outcomes. Purpose To compare the angiographic and clinical outcomes of the WEB device for the treatment of sidewall aneurysms compared with the treatment of bifurcation aneurysms. Materials and Methods A retrospective review of the WorldWideWEB Consortium, a synthesis of retrospective databases spanning from January 2011 to June 2021 at 22 academic institutions in North America, South America, and Europe, was performed to identify patients with intracranial aneurysms treated with the WEB device. Characteristics and outcomes were compared between bifurcation and sidewall aneurysms. Propensity score matching (PSM) was used to match by age, pretreatment ordinal modified Rankin Scale score, ruptured aneurysms, location of aneurysm, multiple aneurysms, prior treatment, neck, height, dome width, daughter sac, and incorporated branch. Results A total of 683 intracranial aneurysms were treated using the WEB device in 671 patients (median age, 61 years [IQR, 53-68 years]; male-to-female ratio, 1:2.5). Of those, 572 were bifurcation aneurysms and 111 were sidewall aneurysms. PSM was performed, resulting in 91 bifurcation and sidewall aneurysms pairs. No significant difference was observed in occlusion status at last follow-up, deployment success, or complication rates between the two groups. Conclusion No significantly different outcomes were observed following the off-label use of the Woven EndoBridge, or WEB, device for treatment of sidewall aneurysms compared with bifurcation aneurysms. The correct characterization of the sidewall aneurysm location, neck angle, and size is crucial for successful treatment and lower retreatment rate. © RSNA, 2022 See also the editorial by Hetts in this issue.

Role of diabetes in collateral status assessed in CT perfusion-derived dynamic CTA in anterior circulation stroke.

PURPOSE: Diabetes is associated with vascular dysfunction potentially impairing collateral recruitment in acute ischemic stroke. This retrospective study aimed at analyzing the impact of diabetes on collateralization assessed on dynamic CTA. METHODS: Collaterals were retrospectively assessed on CT perfusion-derived dynamic CTA according to the mCTA score by Menon in a cohort of patients with an acute occlusion of the M1 segment or carotid T. The extent of collateral circulation was related to the history of diabetes and to admission blood glucose and HbA1c levels. RESULTS: Two hundred thirty-nine patients were included. The mCTA collateral score was similar in patients with diabetes (median 3, interquartile range 3-4) and without diabetes (median 4, interquartile range 3-4) (P = 0.823). Diabetes was similarly frequent in patients with good (18.8%), intermediate (16.1%), and poor collaterals (16.0%) (P = 0.355). HbA1c was non-significantly higher in patients with poor collaterals (6.3 ± 1.5) compared to patients with intermediate (6.0 ± 0.9) and good collaterals (5.8 ± 0.9) (P = 0.061). Blood glucose levels were significantly higher in patients with poor compared to good collaterals (mean 141.6 vs. 121.8 mg/dl, P = 0.045). However, there was no significant difference between good and intermediate collaterals (mean 121.8 vs. 129.5 mg/dl, P = 0.161) as well as between intermediate and poor collaterals (129.5 vs. 141.6 mg/dl, P = 0.161). CONCLUSION: There was no statistically significant difference among patients with good, intermediate, and poor collaterals regarding the presence of diabetes or HbA1c level on admission. However, stroke patients with poor collaterals tend to have higher blood glucose and HbA1c levels.

Benefit of mechanical thrombectomy in acute ischemic stroke related to calcified cerebral embolus.

PURPOSE: Mechanical thrombectomies (MT) in patients with large vessel occlusion (LVO) related to calcified cerebral embolus (CCE) have been reported, through small case series, being associated with low reperfusion rate and worse outcome, compared to regular MT. The purpose of the MASC (Mechanical Thrombectomy in Acute Ischemic Stroke Related to Calcified Cerebral Embolus) study was to evaluate the incidence of CCEs treated by MT and the effectiveness of MT in this indication. METHODS: The MASC study is a retrospective multicentric (n = 37) national study gathering the cases of adult patients who underwent MT for acute ischemic stroke with LVO related to a CCE in France from January 2015 to November 2019. Reperfusion rate (mTICI ≥ 2B), complication rate and 90-day mRS were systematically collected. We then conducted a systematic review by searching for articles in PubMed, Cochrane Library, Embase and Google Scholar from January 2015 to March 2020. A meta-analysis was performed to estimate clinical outcome at 90 days, reperfusion rate and complications. RESULTS: We gathered data from 35 patients. Reperfusion was obtained in 57% of the cases. Good clinical outcome was observed in 28% of the patients. The meta-analysis retrieved 136 patients. Reperfusion and good clinical outcome were obtained in 50% and 29% of the cases, respectively. CONCLUSION: The MASC study found worse angiographic and clinical outcomes compared to regular thrombectomies. Individual patient-based meta-analysis including the MASC findings shows a 50% reperfusion rate and a 29% of good clinical outcome.

Clinical Outcome After Endovascular Thrombectomy in 3 Triage Concepts: A Prospective, Observational Study (NEUROSQUAD).

BACKGROUND AND PURPOSE: NEUROSQUAD (Stroke Treatment: Quality and Efficacy in Different Referral Systems) is a prospective, observational, bicenter study comparing 3 triage pathways in endovascular stroke treatment: mothership, drip and ship (DS), and transferring a neurointerventionalist to a remote hospital for thrombectomy (drive the doctor [DD]). METHODS: Patients with anterior circulation stroke and premorbid modified Rankin Scale (mRS) score 0-3 who underwent thrombectomy within 24 hours after stroke onset were included. Primary outcome measure was good clinical outcome defined as 90-day mRS score 0-2 or clinical recovery to the status before stroke onset (ie, equal premorbid mRS and 90-day mRS). Secondary outcome measures were successful reperfusion, National Institutes of Health Stroke Scale at discharge, and mRS shift. RESULTS: In total, 360 patients were included in this study, of whom 111 patients (30.8%) were in the mothership group, 204 patients (56.7%) were in the DS group, and 45 patients (12.5%) were in the DD group. Good clinical outcome was achieved similarly in all three groups (mothership, 45.9%; DS, 43.1%; DD, 40.0%; P=0.778). Likewise, frequency of successful reperfusion was similar in all three groups (mothership, 86.5%; DS, 85.3%; DD, 82.2%; P=0.714). There was no significant difference among the groups regarding the National Institutes of Health Stroke Scale at discharge (P=0.115) and mRS shift (P=0.342). In the multivariate analysis, triage concept was not an independent predictor of good outcome (unadjusted odds ratio, 0.89 [CI, 0.64-1.23]; P=0.479). CONCLUSIONS: Our data suggest that clinical outcome after thrombectomy is similar in mothership, DS, and DD. Hence, DD can be a valuable triage option in acute stroke treatment.

Predictors for Failure of Early Neurological Improvement After Successful Thrombectomy in the Anterior Circulation.

BACKGROUND AND PURPOSE: Failure of early neurological improvement (fENI) despite successful mechanical thrombectomy in the anterior circulation is a clinically frequent occurrence. Purpose of this analysis was to define independent clinical, radiological, laboratory, or procedural predictors for fENI. METHODS: Retrospective single-center analysis of patients treated for acute ischemic stroke in the anterior circulation ensuing successful mechanical thrombectomy between January 2014 and April 2019. Patients were compared according to fENI (equal or higher National Institutes of Health Stroke Scale) and ENI (lower National Institutes of Health Stroke Scale at discharge). Thirty-eight variables were examined in multivariable analysis for association with fENI. RESULTS: Five hundred forty-nine out of 1146 patients experienced successful recanalization (modified Treatment in Cerebral Ischemia 2c-3). fENI occurred in 115/549 (20.9%) patients. Independent predictors of fENI were premorbid modified Rankin Scale (odds ratio [OR] per point [IC], 1.21 [1.00-1.46], P=0.049), end-stage renal failure (OR [IC], 12.18 [2.01-73.63], P=0.007), admission glucose (OR [IC], 1.018 [1.004-1.013] per mg/dL, P=0.001), bridging IV lysis (OR [IC], 0.57 [0.35-0.93], P: 0.024), time from groin puncture to final recanalization (OR [IC], 1.004 [1.001-1.007] per minute, P=0.015), general anesthesia during mechanical thrombectomy (OR, 2.41 [1.43-4.08], P<0.001), symptomatic intracranial hemorrhage (OR [CI], 6.81 [1.84-25.16], P=0.004), and follow-up Alberta Stroke Program Early CT Score (OR [IC], 0.76 [0.69-0.84] per point, P<0.001). In a secondary analysis, involvement of the regions internal capsule, M4 and M5 (motor cortex) were further independent predictors for fENI. Patients with ENI were more likely to experience a good outcome (modified Rankin Scale on day 90, 0-2: n=229/435 [52.8%] versus n=13/115 [11.3%]; P<0.001). CONCLUSIONS: The extent of infarction and the involvement of motor cortex and internal capsule as well as higher premorbid modified Rankin Scale, end-stage renal failure, high glucose level on admission, absence of bridging IV lysis, general anesthesia, and a longer therapy interval are presumably independent predictors for fENI in patients with successful mechanical thrombectomy.