Endovascular revascularization of vertebrobasilar tandem occlusions in comparison to isolated basilar artery occlusions: A multi-center experience.

BACKGROUND: Acute basilar artery occlusion (BAO) is a severe disease that is associated with an 85% mortality rate if untreated. Several studies have analyzed the use of mechanical thrombectomy (MT) in the different scenarios of BAO. However, the results remain conflicting and the role of MT as standard of care for vertebrobasilar tandem occlusions (VBTO) has not been confirmed. Our goal was to assess technical feasibility, safety, and functional outcome of endovascular treatment of VBTO in comparison to isolated BAO (IBAO). METHODS: We retrospectively reviewed all prospectively collected patients with acute BAO from six tertiary centers between September 2016 and November 2021. Patients were subsequently divided into two groups: VBTO and IBAO. Baseline data, procedural details, and outcomes were compared between groups. RESULTS: A total of 190 patients were included, 55 presenting with a VBTO and 135 with IBAO. Successful recanalization was equally common in both groups (89.1% and 86.0%). Rates of favorable functional outcome (modified Rankin Scale: 0-2) were higher in patients with VBTO compared to IBAO (36.4% vs. 25.2%, p = 0.048) and mortality was lower (29.1% vs. 33.3%). However, these associations faded after adjustment for confounders (adjusted odds ratio [aOR] 0.86, 95% CI 0.35-2.05; aOR 0.93, 95% CI 0.35-2.45). Rates of symptomatic intracranial hemorrhage did not differ between the groups (VBTO: 7.3% vs. IBAO: 4.2%; p = 0.496). CONCLUSION: Endovascular treatment of VBTO is technically feasible and safe with similar rates of successful recanalization, favorable functional outcome, and mortality to those in patients with IBAO.

Impact of ischemic stroke topography on early clinical outcome of basilar artery occlusion: a retrospective study.

OBJECTIVES: Basilar artery occlusion (BAO) may be etiologically attributed to embolism or in situ thrombosis due to basilar stenosis (BS). Patients with BAO due to BS (BAOS) are known to have worse outcomes than patients with embolic occlusions (BAOE). BAOS occurs more proximally in the basilar artery (BA) than BAOE. We hypothesize that differing brain stem infarct patterns contribute to outcome differences between these stroke etiologies. METHODS: This retrospective study includes 199 consecutive patients with BAO who received endovascular treatment at a single center. Final infarction in brain parenchyma dependent on the posterior circulation was graded semiquantitatively on magnetic resonance imaging (MRI). Associations to underlying stenosis and angiographic and clinical outcome variables were tested. The primary endpoint was early good clinical outcome (EGCO, mRS score ≤ 3 at discharge). RESULTS: Infarct extension of the medulla oblongata (OR = 0.25; 95% CI = 0.07-0.86; p = 0.03), the inferior pons (OR = 0.328; 95% CI = 0.17-0.63; p = 0.001), the superior pons (OR = 0.57; 95% CI = 0.33-0.99; p = 0.046), and the occipital lobes (OR = 0.46; 95% CI = 0.26-0.80; p = 0.006) negatively predicted EGCO. Infarct extension for other posterior-circulation-dependent brain regions was not independently associated with unfavorable early outcomes. Patients with BAOS had more proximal occlusions and greater infarct volumes in the inferior brain stem. Successful reperfusion (mTICI 2b-3) occurred more often in patients with BAOE than in BAOS (BAOE: 131 (96.3%); BAOS: 47 (83.9%), p = 0.005). CONCLUSION: Unfavorable early outcomes in patients with BAOS may be explained by a higher likelihood of inferior brain stem infarcts and lower rates of reperfusion success. CLINICAL RELEVANCE STATEMENT: Basilar artery occlusion due to underlying stenosis is associated with a poorer prognosis than that caused by embolism; these results suggest that aggressive endovascular therapy, usually involving the placement of a permanent stent, may be warranted in these patients. KEY POINTS: Inferior brain stem and occipital infarcts are prognostically unfavorable in basilar artery occlusion. Basilar artery occlusion due to stenosis occurs more proximally and is associated with worse outcomes. Differentiating etiologies of basilar artery occlusion may influence how aggressively treated the occlusion is.

Effect of anesthetic strategies on distal stroke thrombectomy in the anterior and posterior cerebral artery.

BACKGROUND: Numerous questions regarding procedural details of distal stroke thrombectomy remain unanswered. This study assesses the effect of anesthetic strategies on procedural, clinical and safety outcomes following thrombectomy for distal medium vessel occlusions (DMVOs). METHODS: Patients with isolated DMVO stroke from the TOPMOST registry were analyzed with regard to anesthetic strategies (ie, conscious sedation (CS), local (LA) or general anesthesia (GA)). Occlusions were in the P2/P3 or A2-A4 segments of the posterior and anterior cerebral arteries (PCA and ACA), respectively. The primary endpoint was the rate of complete reperfusion (modified Thrombolysis in Cerebral Infarction score 3) and the secondary endpoint was the rate of modified Rankin Scale score 0-1. Safety endpoints were the occurrence of symptomatic intracranial hemorrhage and mortality. RESULTS: Overall, 233 patients were included. The median age was 75 years (range 64-82), 50.6% (n=118) were female, and the baseline National Institutes of Health Stroke Scale score was 8 (IQR 4-12). DMVOs were in the PCA in 59.7% (n=139) and in the ACA in 40.3% (n=94). Thrombectomy was performed under LA±CS (51.1%, n=119) and GA (48.9%, n=114). Complete reperfusion was reached in 73.9% (n=88) and 71.9% (n=82) in the LA±CS and GA groups, respectively (P=0.729). In subgroup analysis, thrombectomy for ACA DMVO favored GA over LA±CS (aOR 3.07, 95% CI 1.24 to 7.57, P=0.015). Rates of secondary and safety outcomes were similar in the LA±CS and GA groups. CONCLUSION: LA±CS compared with GA resulted in similar reperfusion rates after thrombectomy for DMVO stroke of the ACA and PCA. GA may facilitate achieving complete reperfusion in DMVO stroke of the ACA. Safety and functional long-term outcomes were comparable in both groups.

Interdisciplinary Rendez-Vous Approach in Endovascular Stroke Treatment: A New Concept to Accelerate Mechanical Thrombectomy in Primary Stroke Centers.

PURPOSE: Prompt endovascular treatment of patients with stroke due to intracranial Large Vessel Occlusion (LVO) is a major challenge in rural areas because neurointerventionalists are usually not available. As a result, treatment is delayed, and clinical outcomes are worse compared with patients primarily treated in comprehensive stroke centers (CSC). To address this problem, we present a concept in which interdisciplinary, on-site endovascular treatment is performed in a Primary Stroke Center (PSC) by a team of interventional neuroradiologists and cardiologists: the Rendez-Vous approach. METHODS: Thirty-five patients with LVO who underwent interdisciplinary thrombectomy on-site at the PSC as part of the Rendez-Vous concept were compared with 72 patients who were transferred from a PSCs to the CSC for thrombectomy when diagnosed with LVO in terms of temporal sequences and clinical outcomes. RESULTS: Patients treated on-site at the PSC as part of the Rendez-Vous approach were managed as successfully and without an increase in complication rates compared with patients treated secondarily at a CSC (91.7% successful interventions in Rendez-Vous vs. 87.3% in control group, p = 0.57). The time from diagnosis of LVO to groin puncture was reduced by mean 74.3 min with the Rendez-Vous concept (p < 0.01). Regarding the clinical outcome, a functionally independent status was achieved in 45.5% in the Rendez-Vous group and in 22.6% in the control group (p = 0.029). CONCLUSION: Thanks to interdisciplinary teamwork between cardiology and interventional neuroradiology in local PSCs, times to successful reperfusion can be reduced. This has a potentially positive impact on the clinical outcome of stroke patients.

Inflammation in stroke: initial CRP levels can predict poor outcomes in endovascularly treated stroke patients.

Background and purpose: Inflammation has been linked to poor prognoses in cardio- and cerebrovascular conditions. As it is known to increase after ischemia, C-reactive protein (CRP) may serve as a surrogate for systemic inflammation and thus be a hallmark of increased tissue vulnerability. The question arises whether CRP in the acute phase of ischemic stroke, prior to mechanical thrombectomy (MT), might help predict outcomes. Materials and methods: A single-center collective of patients with large-vessel occlusion, who were treated via MT, was analyzed in this observational case-control study. Univariate and multivariate models were designed to test the prognostic value of inflammatory markers (CRP and leukocytosis) in predicting clinical outcomes (modified Rankin score >2) and all-cause mortality 90 days after MT. Results: A total of 676 ischemic stroke patients treated with MT were included. Of these, 313 (46.3%) showed elevated CRP levels (≥5 mg/l) on admission. Poor clinical outcome and mortality at 90 days occurred in 113 (16.7%) and 335 (49.6%) patients and significantly more frequently when initial CRP levels were elevated [213 (64.5%) vs. 122 (42.1%), p < 0.0001, and 79 (25.2%) vs. 34 (9.4%), p < 0.0001, respectively]. CRP levels were highly predictive for impaired outcomes, especially in patients with atrial fibrillation, in both univariate and multivariate models. Interestingly, patients with initially elevated CRP levels also showed more pronounced increases in CRP post-MT. Conclusion: Poor outcome and death occur significantly more often in stroke patients with elevated CRP levels before MT. Our findings suggest that stroke patients with atrial fibrillation and elevated inflammatory markers are of particular risk for poor outcomes.

Symptomatic intracranial hypertension in an adult patient with spinal muscular atrophy and arachnoid cysts receiving nusinersen.

 In patients with spinal muscular atrophy (SMA) headache after intrathecal administration of nusinersen is usually attributed to post-lumbar puncture syndrome. However, lumbar puncture opening pressure (LOP) has also been reported to be increased in children with SMA, both before and after treatment with nusinersen, although symptoms associated with increased LOP were not observed. We report to our knowledge the first case of symptomatic intracranial hypertension in an adult SMA patient. This 21-year-old man suffered from headache and vomiting followed by visual disturbances after the 12th injection of nusinersen. Bilateral papilledema was recognized ophthalmologically. MRI of the head showed signs of intracranial hypertension and additionally arachnoid cysts but not hydrocephalus. Symptoms resolved after 8 weeks of treatment with repeated lumbar punctures and acetazolamide. This case raises the possibility of intracranial hypertension as a complication of nusinersen therapy although arachnoid cysts represent another risk factor for intracranial hypertension. We recommend that patients suffering from headache after nusinersen injections should not only be questioned and examined for symptoms suggestive of post-lumbar puncture syndrome, but also intracranial hypertension.

Mechanical thrombectomy of distal cerebral vessel occlusions of the anterior circulation.

Mechanical thrombectomy (MT) is frequently performed for distal medium vessel occlusions (DMVO) of the anterior circulation in acute stroke patients. However, evidence for its clinical benefit remains scarce. In this study, we aim to investigate clinical course and safety outcomes of MT in comparison to standard medical therapy (SMT) in DMVO. This single-center retrospective observational study included 138 consecutive patients treated for DMVO of the anterior circulation between 2015 and 2021. To reduce the risk of selection bias, propensity score matching (PSM) of patients with MT versus SMT was performed for the covariates NIHSS and mRS at admission. Out of all 138 patients, 48 (34.8%) received MT and 90 (65.2%) received SMT only. Overall, patients treated with MT showed significantly higher NIHSS and mRS scores at admission. Post 1:1 PSM, there was a trend toward a better NIHSS improvement in patients with MT (median 4 vs. 1, P = 0.1). No significant differences were observed in the occurrence of symptomatic intracranial hemorrhage or mortality between the groups before and after PSM. A subgroup analysis showed significantly higher NIHSS improvement (median 5 versus 1, P = 0.01) for patients with successful MT (≥ mTICI 2b). Mechanical thrombectomy for distal medium vessel occlusions (DMVO) in the anterior circulation appeared safe and feasible. Successful recanalization was associated with clinical improvement. Larger, multi-center, randomized-controlled trials are required to corroborate these findings.

Outcome and risk of hemorrhage in patients with tandem lesions after endovascular treatment: A propensity score-matched case-control study.

Objectives: Endovascular treatment of acute stroke patients with large vessel occlusions is well established. But tandem lesions of the internal carotid artery and the intracranial anterior circulation remain a challenge regarding the technical conditions and the putative higher risk of hemorrhage due to often required antiplatelet therapy.This study aims to evaluate the clinical outcome and the risk of hemorrhage after endovascular treatment of tandem lesions, with special regard to the periprocedural antiplatelet regimen. Materials and Methods: In this retrospective study, we included 63 consecutive stroke patients with endovascular treated tandem lesions. One hundred eleven patients with a solitary intracranial occlusion were matched using a "propensity score-matched analysis" with the covariates sex, age, wake-up stroke, iv-thrombolysis and NIHSS. Results: Rates of successful recanalization (mTICI 2b/3) and periprocedural complications were equal in both groups (P = 0.19; P = 0.35). The rate of good clinical outcome (mRS≤2) was similar, and the incidence of symptomatic hemorrhages was not significantly different (7.9% tandem lesions vs. 5.4% isolated intracranial occlusion, P = 0.51). Even intensified antiplatelet therapy in patients with tandem lesions did not increase the rate of symptomatic intracranial hemorrhages (P = 0.87). Conclusions: Clinical outcome and symptomatic intracranial hemorrhages did not differ significantly between endovascular treated patients with tandem lesions and matched patients with solitary intracranial occlusions, regardless of the antiplatelet regimen. Therefore, the complex technical requirements for recanalization of a tandem lesion and the putative higher risk should not result in reluctant treatment that would decrease the chance of a good clinical outcome.

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.

Endovascular thrombectomy for basilar artery occlusion stroke: Analysis of the German Stroke Registry-Endovascular Treatment.

BACKGROUND AND PURPOSE: Acute ischemic stroke due to basilar artery occlusion (BAO) causes the most severe strokes and has a poor prognosis. Data regarding efficacy of endovascular thrombectomy in BAO are sparse. Therefore, in this study, we performed an analysis of the therapy of patients with BAO in routine clinical practice. METHODS: Patients enrolled between June 2015 and December 2019 in the German Stroke Registry-Endovascular Treatment (GSR-ET) were analyzed. Primary outcomes were successful reperfusion (modified Thrombolysis in Cerebral Infarction [mTICI] score of 2b-3), substantial neurological improvement (≥8-point National Institute of Health Stroke Scale [NIHSS] score reduction from admission to discharge or NIHSS score at discharge ≤1), and good functional outcome at 3 months (modified Rankin Scale [mRS] score of 0-2). RESULTS: Out of 6635 GSR-ET patients, 640 (9.6%) patients (age 72.2 ± 13.3, 43.3% female) experienced BAO (median [interquartile range] NIHSS score 17 [8, 27]). Successful reperfusion was achieved in 88.4%. Substantial neurological improvement at discharge was reached by 45.5%. At 3-month follow-up, good clinical outcome was observed in 31.1% of patients and the mortality rate was 39.2%. Analysis of mTICI3 versus mTICI2b groups showed considerable better outcome in those with mTICI3 (38.9% vs. 24.4%; p = 0.005). The strongest predictors of good functional outcome were intravenous thrombolysis (IVT) treatment (odds ratio [OR] 3.04, 95% confidence interval [CI] 1.76-5.23) and successful reperfusion (OR 4.92, 95% CI 1.15-21.11), while the effect of time between symptom onset and reperfusion seemed to be small. CONCLUSIONS: Acute reperfusion strategies in BAO are common in daily practice and can achieve good rates of successful reperfusion, neurological improvement and good functional outcome. Our data suggest that, in addition to IVT treatment, successful and, in particular, complete reperfusion (mTICI3) strongly predicts good outcome, while time from symptom onset seemed to have a lower impact.

Start, Stop, Continue? The Benefit of Overlapping Intravenous Thrombolysis and Mechanical Thrombectomy : A Matched Case-control Analysis from the German Stroke Registry.

OBJECTIVE: Here we compare the procedural and clinical outcome of patients undergoing thrombectomy with running thrombolysis to matched controls with completed intravenous therapy and an only marginally overlapping activity. METHODS: Patients from 25 sites in Germany were included, who presented with an acute ischemic stroke. Patients' baseline characteristics (including ASPECTS, NIHSS and mRS), grade of reperfusion, and functional outcome 24 h and at day 90 after intervention were extracted from the German Stroke Registry (n = 2566). In a case-control design we stepwise matched the groups due to age, sex and time to groin puncture and time to flow restoration. RESULTS: In the initial cohort (overlap group n = 864, control group n = 1702) reperfusion status (median TICI in overlap group vs. control group: 3 vs. 2b), NIHSS after 24 h, early neurological improvement parameters, mRS at 24 h and at day 90 were significantly better in the overlap group (p < 0.001) with a similar risk of bleeding (2.9% vs. 2.4%) and death (18% vs. 22%). After adjustment mRS at day 90 still showed a trend for lower disability scores in the overlap group (3 IQR 1-5 vs. 3 IQR 1-6, p = 0.09). While comparable bleeding risk could be maintained (4% in both groups), there were significantly more deaths in the control group (18% vs. 30%, p = 0.006). CONCLUSION: The presented results support the approach of continuing and completing a simultaneous administration of intravenous thrombolysis during mechanical thrombectomy procedures.

Feasibility, Safety, and Technical Success of the Flying Intervention Team in Acute Ischemic Stroke : Comparison of Interventions in Different Primary Stroke Centers with those in a Comprehensive Stroke Center.

BACKGROUND: Prompt endovascular care of patients with ischemic stroke due to large vessel occlusion (LVO) remains a major challenge in rural regions as primary stroke centers (PSC) usually cannot provide neuro-interventional services. Objective The core content of the Flying Intervention Team (FIT) project is to perform thrombectomy on-site at a local PSC after the neuro-interventionalist has been transported via helicopter to the target hospital. An important and so far unanswered question is whether mechanical thrombectomy can be performed as safely and successfully on-site as in a specialized comprehensive stroke center (CSC). METHODS: Comparison of 100 FIT thrombectomies on site in 14 different PSCs with 128 control thrombectomies at 1 CSC (79 drip-and-ship, 49 mothership) performed by a single interventionalist with respect to technical-procedural success parameters, procedural times, and complications. RESULTS: There were no significant differences between the two groups in terms of technical success (95.0% successful interventions in FIT group vs. 94.5% in control group, p = 0.60) and complications (3% major complications in FIT vs. 1.6% in control group, p = 0.47). Regarding time from onset to groin puncture, there was no difference between FIT and the entire control group (182 vs. 183 min, p = 0.28), but a trend in favor of FIT compared with the drip-and-ship control subgroup (182 vs. 210 min, p = 0.096). CONCLUSIONS: Airborne neuro-interventional thrombectomy service is a feasible approach for rural regions. If performed by experienced neuro-interventionalists, technical success and complication rates are comparable to treatment in a specialized neuro-interventional department.

Breaking with a dogma: persisting diffusion restrictions (pDWI) in follow-up after endovascular treatment for stroke.

BACKGROUND: Post-stroke diffusion weighted imaging (DWI) signal transformation of the infarct core, which results in high apparent diffusion coefficient (ADC) values and variable DWI signal intensity, is completed no later than 1 month after onset of ischemia. We observed frequent exceptions to this timeline of change in DWI signal, which led to uncertainties in further clinical patient management. METHODS: A prospective single-center study of patients treated with mechanical thrombectomy of a large vessel occlusion in the anterior circulation was conducted. Patients received high-resolution MRI at 3T, including DWI, in the acute post-stroke phase and in the follow-up after 3-12 months. RESULTS: Overall, 78 patients (45 men) of mean age 63.6 years were evaluated. We identified persisting or new diffusion restriction in 29 of the 78 patients (37.2%) on follow-up imaging. Diffusion restrictions in a different location from the infarct core, representing new (sub-)acute ischemia, were observed in four patients (5.1%). Smaller areas of persisting diffusion restriction (pDWI lesions with high DWI signal and reduced ADC values) within the former infarct core were observed in 25 patients (32.1%) without clinical evidence of recurrent stroke, but with worse outcome scores at follow-up compared with patients without pDWI lesions. The presence of pDWI lesions is associated with a large primary infarct core (multivariate regression OR 1.03 (95% CI 1.01 to 1.05); p<0.01), mediating the relationship between pDWI lesions and clinical outcome. CONCLUSION: Smaller foci of persisting diffusion restriction (pDWI lesions) in the follow-up after endovascular treatment for stroke are frequent and likely represent a slowed ADC signal progression within a formerly large infarct core.

Bridging intravenous thrombolysis in patients with atrial fibrillation.

Background and purpose: 40% of acute ischemic stroke patients treated by mechanical thrombectomy (MT) have a clinical history of atrial fibrillation (AF). The safety of bridging intravenous thrombolysis (IVT) (MT + IVT) is currently being discussed. We aimed to analyze the interaction between oral anticoagulation (OAC) status or AF with bridging IVT, regarding the occurrence of symptomatic intracranial hemorrhage (sICH) and functional outcome. Materials and Methods: Multicentric observational cohort study (BEYOND-SWIFT registry) of consecutive patients undergoing MT between 2010 and 2018 (n = 2,941). Multinomial regression models were adjusted for prespecified baseline and plausible pathophysiological covariates identified on a univariate analysis to assess the association of AF and OAC status with sICH and good outcomes (90-day modified Rankin Scale score 0-2). Results: In the total cohort (median age 74, 50.6% women), 1,347 (45.8%) patients had AF. Higher admission National Institutes of Health Stroke Scale (NIHSS) score (aOR 1.04 [95% 1.02-1.06], per point of increase) and prior medication with Vitamin K antagonists (VKA) (aOR 2.19 [95% 1.27-3.66]) were associated with sICH. Neither AF itself (aOR 0.71 [95% 0.41-1.24]) nor bridging IVT (aOR 1.08 [0.67-1.75]) were significantly associated with increased sICH. Receiving bridging IVT (aOR 1.61 [95% 1.24-2.11]) was associated with good 90-day outcome, with no interaction between AF and IVT (p = 0.92). Conclusion: Bridging IVT appears to be a reasonable clinical option in selected patients with AF. Given the increased sICH risk in patients with VKA, subgroup analysis of the randomized controlled trials should analyze whether patients with VKA might benefit from withholding bridging IVT. Registration: clinicaltrials.gov; Unique identifier: NCT03496064.

CT Marker in Emergency Imaging of Acute Basilar Artery Occlusion: Thrombosis vs. Embolism.

Purpose: Acute basilar artery occlusion, a neurovascular emergency leading to high rates of morbidity and mortality, is usually diagnosed by CT imaging. The outcome is partly dependent on etiology, with a worse outcome in occlusions with underlying basilar artery stenosis. As this occlusion type requires a more complex angiographic therapy, this study aimed to develop new CT markers in emergency admission imaging to rapidly identify underlying stenosis. Methods: A total of 213 consecutive patients (female n = 91, age in years (mean/SD/range): 72/13/28−97), who received endovascular treatment at a single comprehensive stroke center for acute basilar artery occlusion, were included in this study. After applying strict inclusion criteria for imaging analyses, novel CT imaging markers, such as 'absolute density loss' (ADL) and relative thrombus attenuation (CTA-index), that measure perviousness, were assessed for n = 109 patients by use of CT-angiography and correlated to different occlusion patterns (thrombotic vs. embolic). Inter-observer agreement was assessed using an intraclass correlation coefficient for independent measures of a radiologist and a neuroradiologist. Associations between the imaging markers and clinical and interventional parameters were tested. Results: CT markers differ between the subgroups of basilar artery occlusions with and without underlying stenosis (for ADL: 169 vs. 227 HU (p = 0.03), for CTA-index: 0.55 vs. 0.70 (p < 0.001)), indicating a higher perviousness in the case of stenosis. A good inter-rater agreement was observed for ADL and CTA-index measures (ICC 0.92/0.88). For the case of embolic occlusions, a more pervious thrombus correlates to shorter time intervals, longer procedure times, and worse reperfusion success (p-values < 0.05, respectively). Conclusions: ADL and CTA-index are easy to assess in the emergency setting of acute basilar artery occlusion with the use of routinely acquired CT-angiography. They show a high potential to differentiate thrombotic from embolic occlusions, with an impact on therapeutic decisions and angiographic procedures. Measurements can be quickly performed with good reliability, facilitating implementation in clinical practice.

Association Between Use of a Flying Intervention Team vs Patient Interhospital Transfer and Time to Endovascular Thrombectomy Among Patients With Acute Ischemic Stroke in Nonurban Germany.

Importance: The benefit of endovascular thrombectomy (EVT) for acute ischemic stroke is highly time-dependent, and it is challenging to expedite treatment for patients in remote areas. Objective: To determine whether deployment of a flying intervention team, compared with patient interhospital transfer, is associated with a shorter time to endovascular thrombectomy and improved clinical outcomes for patients with acute ischemic stroke. Design, Setting, and Participants: This was a nonrandomized controlled intervention study comparing 2 systems of care in alternating weeks. The study was conducted in a nonurban region in Germany including 13 primary telemedicine-assisted stroke centers within a telestroke network. A total of 157 patients with acute ischemic stroke for whom decision to pursue thrombectomy had been made and deployment of flying intervention team or patient interhospital transfer was initiated were enrolled between February 1, 2018, and October 24, 2019. The date of final follow-up was January 31, 2020. Exposures: Deployment of a flying intervention team for EVT in a primary stroke center vs patient interhospital transfer for EVT to a referral center. Main Outcomes and Measures: The primary outcome was time delay from decision to pursue thrombectomy to start of the procedure in minutes. Secondary outcomes included functional outcome after 3 months, determined by the distribution of the modified Rankin Scale score (a disability score ranging from 0 [no deficit] to 6 [death]). Results: Among the 157 patients included (median [IQR] age, 75 [66-80] y; 80 [51%] women), 72 received flying team care and 85 were transferred. EVT was performed in 60 patients (83%) in the flying team group vs 57 (67%) in the transfer group. Median (IQR) time from decision to pursue EVT to start of the procedure was 58 (51-71) minutes in the flying team group and 148 (124-177) minutes in the transfer group (difference, 90 minutes [95% CI, 75-103]; P < .001). There was no significant difference in modified Rankin Scale score after 3 months between patients in the flying team (n = 59) and transfer (n = 57) groups who received EVT (median [IQR] score, 3 [2-6] vs 3 [2-5]; adjusted common odds ratio for less disability, 1.91 [95% CI, 0.96-3.88]; P = .07). Conclusions and Relevance: In a nonurban stroke network in Germany, deployment of a flying intervention team to local stroke centers, compared with patient interhospital transfer to referral centers, was significantly associated with shorter time to EVT for patients with acute ischemic stroke. The findings may support consideration of a flying intervention team for some stroke systems of care, although further research is needed to confirm long-term clinical outcomes and to understand applicability to other geographic settings.

Ischemic Stroke of Suspected Cardioembolic Origin Despite Anticoagulation: Does Thrombus Analysis Help to Clarify Etiology?

Introduction: Despite sufficient oral anticoagulation (OAC) to prevent cardioembolism, some patients suffer from cerebral ischemic strokes of suspected cardioembolic origin. Reasons for that are not clarified yet. In certain cases, the suspected cardioembolic origin of stroke is questioned. This study aimed to understand the thrombi origin and pathophysiology in patients suffering from stroke despite OAC by the analysis of histologic thrombus composition and imaging characteristics. Materials and Methods: On two distinct cohorts, we retrospectively analyzed histologic (n = 92) and imaging features (n = 64), i.e., thrombus perviousness in admission CT imaging, of cerebral thrombi retrieved by the endovascular treatment for a large vessel occlusion of the anterior circulation. In each group, patients with non-cardioembolic strokes and suspected cardioembolic strokes with or without anticoagulation were compared. Results: Fibrin/platelet content of suspected cardioembolic thrombi (mean/SD 57.2% ± 13) is higher than in non-cardioembolic thrombi (48.9% ± 17; p = 0.01). In suspected cardioembolic thrombi, the fibrin/platelet content does not differ in the subgroups of patients with (57.3% ± 13) and without prior OAC treatment (56.6% ±13; p = 0.8), both with higher values than non-cardioembolic thrombi. Thrombus perviousness (ε) of suspected cardioembolic OAC thrombi (mean/SD: 0.09 ± 0.06) differs significantly from non-cardioembolic thrombi (0.02 ± 0.02; p < 0.001). Further, ε is higher in suspected cardioembolic thrombi with OAC than in cardioembolic thrombi without OAC (0.06 ± 0.03; p = 0.04) and with insufficient OAC (0.04 ± 0.02; p = 0.07). Conclusion: Thrombi of the suspected cardioembolic origin of patients with prior OAC do not differ in their histologic composition from those without prior OAC, but both differ from non-cardioembolic thrombi. These histologic results make a non-cardioembolic etiology for strokes despite prior OAC rather unlikely but favor other reasons for these ischemic events. Perviousness assessment reinforces the histologic findings, with additional information about the OAC thrombi, which present with higher perviousness. This suggests that OAC would not affect the relative histologic thrombus composition but may alter the microstructure, as reflected by perviousness.

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.

Extracranial ultrasound following mechanical thrombectomy in patients with acute stroke.

BACKGROUND AND PURPOSE: Mechanical thrombectomy (MT) is standard care for patients suffering from an ischemic stroke due to a large vessel occlusion. Immediate and follow-up transcranial ultrasound examinations after MT were shown to have a diagnostic benefit. However, it is unclear whether repeated extracranial ultrasound after MT has an additional diagnostic yield, that is, depicts new findings. METHODS: Retrospectively, from our prospective database we identified all patients after MT who presented for a follow-up examination between January 2017 and March 2020 and who had received an ultrasound examination after MT and at follow-up. Clinical data were extracted from our database. Ultrasound images of all patients were revisited to identify new findings at follow-up compared to examination after MT. RESULTS: Ninety-one patients were identified appropriate for further analysis, with a mean age of 67.8 ± 16 years. Median National Institute of Health Stroke Scale at admission was 11 ± 8.5 points. At baseline ultrasound, 18 patients (19.8%) had no atherosclerotic alterations and 73 patients (82.2%) had a plaque burden of ≥1 plaque. During follow-up, in 5 patients (5.5%) a pathological finding presented in first examination evolved dynamically, that is, normalized. Vessel status of all other patients was stable, especially, in no patient a new relevant pathological finding occurred. CONCLUSIONS: Although sonographic normalization of pathologic findings was observed, pathologic new findings were not detected during follow-up. This study provides first data for a discussion of the role of ultrasound in a structured stroke care after MT. However, larger studies are required to improve the understanding.

Thrombectomy for secondary distal, medium vessel occlusions of the posterior circulation: seeking complete reperfusion.

BACKGROUND: Whether to approach distal occlusions endovascularly or not in medium-sized vessels secondary to proximal large vessel occlusion stroke remains unanswered. OBJECTIVE: To investigates the technical feasibility and safety of thrombectomy for secondary posterior circulation distal, medium vessel occlusions (DMVO). METHODS: TOPMOST (Treatment fOr Primary Medium vessel Occlusion STroke) is an international, retrospective, multicenter, observational registry of patients treated for distal cerebral artery occlusions. This study subanalysis endovascularly treated occlusions of the posterior cerebral artery in the P2 and P3 segment secondary preprocedural or periprocedural thrombus migration between January 2014 and June 2020. Technical feasibility was evaluated with the modified Thrombolysis in Cerebral Infarction (mTICI) scale. Procedural safety was assessed by the occurrence of symptomatic intracranial hemorrhage (sICH) and intervention-related serious adverse events. RESULTS: Among 71 patients with secondary posterior circulation DMVO who met the inclusion criteria, occlusions were present in 80.3% (57/71) located in the P2 segment and in 19.7% (14/71) in the P3 segment. Periprocedural migration occurred in 54.9% (39/71) and preprocedural migration in 45.1% (32/71) of cases. The first reperfusion attempt led in 38% (27/71) of all cases to mTICI 3. On multivariable logistic regression analysis, increased numbers of reperfusion attempts (adjusted odds ratio (aOR)=0.39, 95% CI 0.29 to 0.88, p=0.009) and preprocedural migration (aOR=4.70, 95% CI,1.35 to 16.35, p=0.015) were significantly associated with mTICI 3. sICH occurred in 2.8% (2/71). CONCLUSION: Thrombectomy for secondary posterior circulation DMVO seems to be safe and technically feasible. Even though thrombi that have migrated preprocedurally may be easier to retract, successful reperfusion can be achieved in the majority of patients with secondary DMVO of the P2 and P3 segment.