A New Fibrin-Heparine Coated Self-Expanding Stent for the Rescue Treatment of Intracranial Stenosis-a Multicentric Study.

INTRODUCTION: Rescue intracranial stenting is necessary to provide sufficient recanalization after mechanical thrombectomy (MT) in patients with acute large vessel occlusions (LVO) due to an underlying intracranial atherosclerotic disease (ICAD). The CREDO heal is a novel stent that provides a potentially lower thrombogenicity due to surface modification. We present the first multicentric experience with the CREDO heal for acute rescue stenting. METHODS: Data of 81 patients who underwent rescue stenting after MT at 12 centers in Germany and Spain were prospectively collected and retrospectively evaluated. RESULTS: Final mTICI 2b­3 was reached in 95.1% after median two MT maneuvers and stenting. Four periprocedural complications resulted in clinical deterioration (4.9%). Intraparenchymal hemorrhage occurred in one patient (1.2%) and functional independence at FU was reached by 42% of the patients. Most interventions were performed under Gp IIb/IIIa inhibitors. CONCLUSION: CREDO heal was effective and safe in our case series. However, more data is needed to define the optimal antithrombotic regime. The use under single antiplatelet medication is not supported by our study.

Symptomatic intracerebral hemorrhage in proximal and distal medium middle cerebral artery occlusion patients treated with mechanical thrombectomy.

BACKGROUND: Acute ischemic stroke (AIS) caused by distal medium vessel occlusions (DMVOs) represents a significant proportion of overall stroke cases. While intravenous thrombolysis (IVT) has been a primary treatment, advancements in endovascular procedures have led to increased use of mechanical thrombectomy (MT) in DMVO stroke patients. However, symptomatic intracerebral hemorrhage (sICH) remains a critical complication of AIS, particularly after undergoing intervention. This study aims to identify factors associated with sICH in DMVO stroke patients undergoing MT. METHODS: This retrospective analysis utilized data from the Multicenter Analysis of Distal Medium Vessel Occlusions: Effect of Mechanical Thrombectomy (MAD-MT) registry, involving 37 centers across North America, Asia, and Europe. Middle cerebral artery (MCA) DMVO stroke patients were included. The primary outcome measured was sICH, as defined per the Heidelberg Bleeding Classification. Univariable and multivariable logistic regression were used to identify factors independently associated with sICH. RESULTS: Among 1708 DMVO stroke patients, 148 (8.7%) developed sICH. Factors associated with sICH in DMVO patients treated with MT included older age (adjusted odds ratio (aOR) 1.01, 95% confidence interval (95% CI) 1.00 to 1.03, P=0.048), distal occlusion site (M3, M4) compared with medium occlusions (M2) (aOR 1.71, 95% CI 1.07 to 2.74, P=0.026), prior use of antiplatelet drugs (aOR 2.06, 95% CI 1.41 to 2.99, P<0.001), lower Alberta Stroke Program Early CT Scores (ASPECTS) (aOR 0.75, 95% CI 0.66 to 0.84, P<0.001), higher preoperative blood glucose level (aOR 1.00, 95% CI 1.00 to 1.01, P=0.012), number of passes (aOR 1.27, 95% CI 1.15 to 1.39, P<0.001), and successful recanalization (Thrombolysis In Cerebral Infarction (TICI) 2b-3) (aOR 0.43, 95% CI 0.28 to 0.66, P<0.001). CONCLUSION: This study provides novel insight into factors associated with sICH in patients undergoing MT for DMVO, emphasizing the importance of age, distal occlusion site, prior use of antiplatelet drugs, lower ASPECTS, higher preoperative blood glucose level, and procedural factors such as the number of passes and successful recanalization. Pending confirmation, consideration of these factors may improve personalized treatment strategies.

Overestimation of the Ischemic Core Is Associated With Higher Core Lesion Volume and Degree of Reperfusion After Thrombectomy.

Background CT perfusion (CTP)-derived baseline ischemic core volume (ICV) can overestimate the true extent of infarction, which may result in exclusion of patients with ischemic stroke from endovascular treatment (EVT). Purpose To determine whether ischemic core overestimation is associated with larger ICV and degree of recanalization. Materials and Methods This retrospective multicenter cohort study included patients with acute ischemic stroke triaged at multimodal CT who underwent EVT between January 2015 and January 2022. The primary outcome was ischemic core overestimation, which was assumed when baseline CTP-derived ICV was larger than the final infarct volume at follow-up imaging. The secondary outcome was functional independence defined as modified Rankin Scale scores of 0-2 90 days after EVT. Successful vessel recanalization was defined as extended Thrombolysis in Cerebral Infarction score of 2b or higher. Categorical variables were compared between patients with ICV of 50 mL or less versus large ICV greater than 50 mL with use of the χ2 test. Adjusted multivariable logistic regression analyses were used to assess the primary and secondary outcomes. Results In total, 721 patients (median age, 76 years [IQR, 64-83 years]; 371 female) were included, of which 162 (22%) demonstrated ischemic core overestimation. Core overestimation occurred more often in patients with ICV greater than 50 mL versus 50 mL or less (48% vs 16%; P < .001) and those with successful versus unsuccessful vessel recanalization (26% vs 13%; P < .001). In an adjusted model, successful recanalization after EVT (odds ratio [OR], 3.14 [95% CI: 1.65, 5.95]; P < .001) and larger ICV (OR, 1.03 [95% CI: 1.02, 1.04]; P < .001) were independently associated with core overestimation, while the time from symptom onset to imaging showed no association (OR, 0.99; P = .96). Core overestimation was independently associated with functional independence (adjusted OR, 2.83 [95% CI: 1.66, 4.81]; P < .001) after successful recanalization. Conclusion Ischemic core overestimation occurred more frequently in patients presenting with large CTP-derived ICV and successful vessel recanalization compared with those with unsuccessful recanalization. © RSNA, 2024 Supplemental material is available for this article.

Brain edema growth after thrombectomy is associated with comprehensive collateral blood flow.

BACKGROUND: We determined whether a comprehensive assessment of cerebral collateral blood flow is associated with ischemic lesion edema growth in patients successfully treated by thrombectomy. METHODS: This was a multicenter retrospective study of ischemic stroke patients who underwent thrombectomy treatment of large vessel occlusions. Collateral status was determined using the cerebral collateral cascade (CCC) model, which comprises three components: arterial collaterals (Tan Scale) and venous outflow profiles (Cortical Vein Opacification Score) on CT angiography, and tissue-level collaterals (hypoperfusion intensity ratio) on CT perfusion. Quantitative ischemic lesion net water uptake (NWU) was used to determine edema growth between admission and follow-up non-contrast head CT (ΔNWU). Three groups were defined: CCC+ (good pial collaterals, tissue-level collaterals, and venous outflow), CCC- (poor pial collaterals, tissue-level collaterals, and venous outflow), and CCCmixed (remainder of patients). Primary outcome was ischemic lesion edema growth (ΔNWU). Multivariable regression models were used to assess the primary and secondary outcomes. RESULTS: 538 patients were included. 157 patients had CCC+, 274 patients CCCmixed, and 107 patients CCC- profiles. Multivariable regression analysis showed that compared with patients with CCC+ profiles, CCC- (ß 1.99, 95% CI 0.68 to 3.30, P=0.003) and CCC mixed (ß 1.65, 95% CI 0.75 to 2.56, P<0.001) profiles were associated with greater ischemic lesion edema growth (ΔNWU) after successful thrombectomy treatment. ΔNWU (OR 0.74, 95% CI 0.68 to 0.8, P<0.001) and CCC+ (OR 13.39, 95% CI 4.88 to 36.76, P<0.001) were independently associated with functional independence. CONCLUSION: A comprehensive assessment of cerebral collaterals using the CCC model is strongly associated with edema growth and functional independence in acute stroke patients successfully treated by endovascular thrombectomy.

Evaluation of effectiveness and safety of the multizone NeVaTM stent retriever for mechanical thrombectomy in ischemic stroke.

PURPOSE: This study aimed to evaluate the effectiveness and safety of the NeVaTM stent retriever as first- and second-line device for mechanical thrombectomy in acute ischemic stroke. METHODS: In this retrospective single-center study, all consecutive patients that underwent mechanical thrombectomy with NeVaTM stent retriever as first- or second-line device due to intracranial vessel occlusion with acute ischemic stroke between March and November 2022 were included. RESULTS: Thirty-nine patients (m=18, f=21) with a mean age of 69.9 ± 13.3 years were treated with the NeVaTM stent retriever. NeVaTM stent retriever was used as first-line device in 24 (61.5%) of patients and in 15 (38.5%) as second-line device. First-pass rate (≥mTICI 2c) of NeVaTM stent retriever was both 66.7% when used as first- or second-line device. Final recanalization rate including rescue strategies was 92.3% for ≥mTICI2c and 94.9% for ≥mTICI2b. No device-related minor or major adverse events were observed. A hemorrhage was detected in 33.3% of patients at 24h post-thrombectomy dual-energy CT, of which none was classified as symptomatic intracerebral hemorrhage. NIHSS and mRS improved significantly at discharge compared to admission (p<0.05). CONCLUSION: The NeVaTM stent retriever has a high effectivity and good safety profile as first- and second-line device for mechanical thrombectomy in acute ischemic stroke.

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.

Stroke in Patients with Bacterial Meningitis: A Cohort Study and Meta-Analysis.

OBJECTIVE: The purpose of this study was to characterize patients with ischemic stroke due to bacterial meningitis. METHODS: In a single-center retrospective study, we analyzed 102 patients with bacterial meningitis of which 19 had an ischemic stroke. Clinical characteristics, cerebrospinal fluid (CSF) analyses, and spatiotemporal distribution of infarcts were assessed. In addition, we searched PubMed from database inception to August 2021 for observational studies on ischemic stroke in patients with bacterial meningitis, and performed a meta-analysis to investigate the frequency and timing of stroke as well as its effect on mortality. RESULTS: In our cohort, 15 (78.9%) patients with stroke had an modified Rankin scale (mRS)  ≥  3 at discharge compared to 33 (39.8%) in patients without stroke (p < 0.01). Of 1,692 patients with bacterial meningitis from 15 cohort studies included in our meta-analysis, cerebral infarcts were found in 332 (16%, 95% confidence interval [CI] = 0.13-0.20) patients. The occurrence of stroke was strongly associated with a higher mortality (odds ratio [OR] = 2.38, 95% CI = 1.70-3.34, p < 0.0001). There was no association of any specific causative pathogen with the occurrence of stroke. Infarcts were mainly distributed in territories of arteries located in the vicinity to the infection focus and peaked at 3 to -7 days and at 2 weeks after onset of meningitis. In patients with ischemic stroke, vasculopathy was found in 63.2% and additional intracerebral hemorrhage in 15.8%. INTERPRETATION: This study found that ischemic stroke due to bacterial meningitis is caused by cerebral vasculopathy located in the vicinity of the infection focus, and that the time course of infarctions might enable a therapeutic intervention. ANN NEUROL 2023;93:1094-1105.

Andexanet-Alfa-Associated Heparin Resistance in the Context of Hemorrhagic Stroke.

BACKGROUND: With a growing number of patients on new oral anticoagulants, interest in reversal agents is rising. Andexanet alfa is used for reversal of factor Xa inhibitors in intracranial hemorrhage. METHODS: We provide a brief review on andexanet-alfa-associated heparin resistance and discuss potentially critical situations from different clinical perspectives. RESULTS: Case reports point out that andexanet alfa can cause unresponsiveness to heparin, leading to catastrophic events. As a result, regulatory bodies have issued warning notices to avoid heparinization parallel to the use of andexanet alfa. CONCLUSIONS: Although well known to hematologists, the phenomenon is underrecognized among stroke clinicians. However, patients with intracranial hemorrhage frequently undergo endovascular or surgical interventions that require periprocedural administration of heparin.

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.

Mechanical thrombectomy for acute ischemic stroke in COVID-19 patients: multicenter experience in 111 cases.

BACKGROUND: Data on the frequency and outcome of mechanical thrombectomy (MT) for large vessel occlusion (LVO) in patients with COVID-19 is limited. Addressing this subject, we report our multicenter experience. METHODS: A retrospective cohort study was performed of consecutive acute stroke patients with COVID-19 infection treated with MT at 26 tertiary care centers between January 2020 and November 2021. Baseline demographics, angiographic outcome and clinical outcome evaluated by the modified Rankin Scale (mRS) at discharge and 90 days were noted. RESULTS: We identified 111 out of 11 365 (1%) patients with acute or subsided COVID-19 infection who underwent MT due to LVO. Cardioembolic events were the most common etiology for LVO (38.7%). Median baseline National Institutes of Health Stroke Scale score and Alberta Stroke Program Early CT Score were 16 (IQR 11.5-20) and 9 (IQR 7-10), respectively. Successful reperfusion (mTICI ≥2b) was achieved in 97/111 (87.4%) patients and 46/111 (41.4%) patients were reperfused completely. The procedure-related complication rate was 12.6% (14/111). Functional independence was achieved in 20/108 (18.5%) patients at discharge and 14/66 (21.2%) at 90 days follow-up. The in-hospital mortality rate was 30.6% (33/108). In the subgroup analysis, patients with severe acute COVID-19 infection requiring intubation had a mortality rate twice as high as patients with mild or moderate acute COVID-19 infection. Acute respiratory failure requiring ventilation and time interval from symptom onset to groin puncture were independent predictors for an unfavorable outcome in a logistic regression analysis. CONCLUSION: Our study showed a poor clinical outcome and high mortality, especially in patients with severe acute COVID-19 infection undergoing MT due to LVO.

Safety, Efficacy, and Durability of Stent Plus Balloon-Assisted Coiling for the Treatment of Wide-Necked Intracranial Bifurcation Aneurysms.

BACKGROUND: Wide-necked bifurcation aneurysms remain a challenge for endovascular surgeons. Dual-stent-assisted coiling techniques have been defined to treat bifurcation aneurysms with a complex neck morphology. However, there are still concerns about the safety of dual-stenting procedures. Stent plus balloon-assisted coiling is a recently described endovascular technique that enables the coiling of wide-necked complex bifurcation aneurysms by implanting only a single stent. OBJECTIVE: To investigate the feasibility, efficacy, safety, and durability of this technique for the treatment of wide-necked bifurcation aneurysms. METHODS: A retrospective review was performed of patients with wide-necked intracranial bifurcation aneurysms treated with stent plus balloon-assisted coiling. The initial and follow-up clinical and angiographic outcomes were assessed. Preprocedural and follow-up clinical statuses were assessed using modified Rankin scale. RESULTS: A total of 61 patients (mean age: 54.6 ± 10.4 yr) were included in the study. The immediate postprocedural digital subtraction angiography revealed complete aneurysm occlusion in 86.9% of the cases. A periprocedural complication developed in 11.5% of the cases. We observed a delayed ischemic complication in 4.9%. There was no mortality in this study. The permanent morbidity rate was 3.3%. The follow-up angiography was performed in 55 of 61 patients (90.1%) (the mean follow-up period was 25.5 ± 27.3 mo). The rate of complete aneurysm occlusion at the final angiographic follow-up was 89.1%. The retreatment rate was 1.8%. CONCLUSION: The results of this study showed that stent plus balloon-assisted coiling is a feasible, effective, and relatively safe endovascular technique for the treatment of wide-necked bifurcation aneurysms located in the posterior and anterior circulation.

Incidence of Acute Kidney Injury After Computed Tomography Angiography±Computed Tomography Perfusion Followed by Thrombectomy in Patients With Stroke Using a Postprocedural Hydration Protocol.

Background The risk of contrast-induced acute kidney injury (AKI) in patients with stroke receiving both computed tomography (CT) angiography and mechanical thrombectomy has been investigated only in small case series. No studies have investigated whether additional CT perfusion or chronic kidney disease (CKD) are associated with higher rates of AKI. Methods and Results Retrospective analysis of the AKI incidence in 1089 consecutive patients receiving CT angiography and mechanical thrombectomy from 2015 to 2017 and in subgroups with CKD (n=99) and CT perfusion (n=104) was performed. Patients received a standardized hydration protocol. Data on kidney function after mechanical thrombectomy were available in 1017 patients. A total of 59 (5.8%) patients developed AKI, and only 4 (6.8%) patients needed hemodialysis, all with known CKD. Patients with AKI significantly more often had known CKD (20.3% versus 8.4%, P=0.002), diabetes mellitus (33.9% versus 20.9%, P=0.018), and tandem occlusion (32.2% versus 16.2%, P=0.003) and a significantly higher in-hospital mortality (20.3% versus 7.0%, P<0.001) compared with patients without AKI. However, there were no significant independent predictors for AKI in multivariable logistic regression analysis. Sex (odds ratio [OR], 2.03; 95% CI, 1.17-3.52 [P=0.012]), higher National Institutes of Health Stroke Scale (OR, 1.10; 95% CI, 1.05-1.14 [P<0.001]), AKI (OR, 3.52; 95% CI, 1.63-7.64 [P=0.001]), diuretic use (OR, 1.80; 95% CI, 1.02-3.19), futile or incomplete recanalization (OR, 0.19; 95% CI, 0.09-0.40 [P<0.001]), and total volume of contrast agent volume (OR, 1.007; 95% CI, 1.002-1.011 [P=0.004]) were independently associated with in-hospital death. Two thirds of the patients with AKI died of severe brain damage and not AKI itself. Conclusions Post-contrast AKI rarely occurs in patients with stroke receiving a contrast agent for CT angiography/CT perfusion and subsequent mechanical thrombectomy. Patients with known CKD had higher rates of AKI and only these patients needed hemodialysis, but CKD was not independently associated with AKI or in-hospital mortality.

Time Point, Etiology, and Short-Term Outcome of Repeated Mechanical Thrombectomy Due to Recurrent Large Vessel Occlusion.

Background: Data on time point and etiology of repeated stroke caused by large brain vessel occlusion (LVO) resulting in repeated mechanical thrombectomy (MT) in acute stroke patients is very limited. Methods: We retrospectively reviewed all acute stroke patients treated with MT with stent retrievers or aspiration systems between January 2010 and June 2018 to identify patients who received two or more MT treatments due to recurrent LVO in our tertiary neurovascular center. Short-term outcome was assessed using the NIH stroke scale score at discharge. Results: We identified 35 out of 2,470 acute stroke patients treated with MT who had recurrent LVO and received repeated MT. Mean age at first MT was 69.3 (±15.8) years and the mean time interval between the first and second MT was 147 (±241) days, and 8 patients experienced short-term LVO recurrence within 3 days. Fifteen (43%) patients had cardioembolic, 9 (26%) arterioembolic, 4 (11%) mixed cardio-/arterioembolic, and 7 (20%) patients had unknown stroke etiology. Patients with cardioembolic stroke were substantially older, had no or insufficient oral anticoagulation at the time of the first and repeated LVO, and repeated LVO occurred very early in 50%. Seventeen (49%) patients had a NIHSS score of 0 or 1 at discharge and seven (20%) patients died in the hospital after repeated MT. No bleeding complications occurred. Conclusions: Repeated MT due to recurrent LVO is a rarely performed, safe, and effective procedure in acute stroke patients. Missing or insufficient anticoagulation is the most frequent cause for recurrent LVO.

The association between collateral status, recanalization and long term outcome in stroke patients treated with stent retrievers - Are there indications not to perform thrombectomy based on CT angiography?

BACKGROUND AND PURPOSE: To investigate the association between baseline pial collateral status on computed tomography angiography (CTA) with recanalization and functional outcome in patients with acute anterior circulation stroke treated with stent retriever thrombectomy. MATERIAL AND METHODS: Retrospective analysis of 87 patients from a prospective thrombectomy registry. Collateral status on CTA source images was categorized into good, moderate, and poor with the Tan and Miteff scores by two-blinded readers. Association between CTA collateral status and successful recanalization was investigated with univariate regression analysis. Multivariate logistic regression was used to analyse the association between collateral score and favourable clinical outcome (mRS 0-2) and death at follow-up. RESULTS: Mean age was 72.5 years and baseline median NIHSS score was 15. Patients with poor collaterals on Tan score had a significant higher mortality compared with moderate or good collaterals during a mean follow-up period of 5.2 months (85.7% vs. 30.6% vs. 25.7%, P<0.001). Univariate logistic regression analysis did not show a significant association between Tan score (OR 1.681, 95% CI 0.683-4.140) and successful recanalization. Higher age (OR 1.067, 95% CI 1.013-1.124; P=0.015) and lower Tan score (OR 0.421, 95% CI 0.192-0.922; P=0.031) were independent predictors of death at follow-up on multivariate analysis. The Miteff collateral score could be assessed only in 65 of the 87 patients and the Tan collateral score had a higher interrater reliability. CONCLUSIONS: Poor collaterals on CTA were associated with a very high rate of fatal outcome in anterior circulation stroke patients despite a high rate of successful recanalization with stent retrievers.

Comparison of outcome and interventional complication rate in patients with acute stroke treated with mechanical thrombectomy with and without bridging thrombolysis.

BACKGROUND: No randomized trial has investigated the effect of mechanical thrombectomy (MT) alone in patients with acute stroke. There are conflicting results as to whether prior intravenous thrombolysis (IVT) facilitates subsequent MT, and data in patients treated with MT alone owing to contraindications to IVT are limited. OBJECTIVE: To compare consecutive patients treated with MT alone or with preceding IVT in a large tertiary neurointerventional center, with special emphasis on contraindications to IVT. METHODS: Retrospective analysis of 283 consecutive patients with acute ischemic stroke treated with MT in a tertiary neurovascular center over 14 months. Data on characteristics of periprocedural times, recanalization rate, complications, and long-term functional outcome were collected prospectively. RESULTS: Information on prior IVT and functional outcome was available in 250 patients. Mean (SD) follow-up period was 5.7 (5.1) months and 105 (42%) patients received both IVT and MT. No significant differences were found in successful recanalization rates (Thrombolysis in Cerebral Infarction (TICI) 2b/3, 73.8% vs 73.1, p=0.952), complication rates, and long-term favorable outcome (modified Rankin Scale 0-2, 35.2% vs 40%, p=0.444) between patients receiving MT plus IVT and those receiving MT alone. A favorable outcome in patients directly treated with MT alone who were eligible for IVT was achieved in 48.2%. Thrombectomy was safe and resulted in a favorable outcome in 32% of patients with absolute contraindications to IVT. CONCLUSIONS: Preceding use of IVT was not an independent predictor of favorable outcome in patients with acute stroke treated with MT and complication rates did not differ whether or not IVT was used. MT is safe and achieved a favorable outcome in one-third of patients with stroke ineligible for IVT.

A new endovascular technique for small anterior choroidal artery aneurysms. A consecutive series using the 3-catheter-protective technique.

INTRODUCTION: Endovascular treatment of small anterior choroidal artery (AChA) aneurysms can be challenging, especially if the AChA arises from the sac. Preserving its patency during embolization is as important as obliterating the aneurysm. We describe a variant of the "protective microcatheter technique" (PMT) in a series of six patients with AChA aneurysms where the AChA emerged from the sac. METHODS: Three different microcatheters (KT) were used. The first microcatheter was placed in the AChA to protect it. A remodeling balloon-catheter was then positioned in the internal carotid artery to stabilize the coils during embolization and to control a potential rupture. The third microcatheter was finally used to coil the aneurysm. RESULTS: Mean sac size of anterior choroidal artery aneurysms was 2×2×2mm. All aneurysms were successfully occluded. There was neither ischemic complication nor ruptured aneurysm during endovascular treatment. A final angiogram demonstrated AChA patency in all cases. CONCLUSION: The 3KT-PMT for AChA aneurysms appears to be safe and effective to prevent AChA occlusion during aneurysm coiling, especially when the AChA arises from the sac.

The pressure cooker technique for the treatment of brain AVMs.

Arteriovenous malformations (AVMs) may be cured by injecting liquid embolic agents such as Onyx. Reflux, however, can sometimes be difficult to control and may jeopardize a complete embolization. The pressure cooker technique (PCT) was designed to create an anti-reflux plug by trapping the detachable part of an Onyx-compatible microcatheter with coils and glue in order to obtain wedge-flow conditions, thereby enabling a better understanding of macrofistulous AVMs and a more comprehensive, forceful and controlled Onyx embolization. The PCT might enlarge the range of AVMs amenable to endovascular cure. Three illustrative cases are presented.

The sheeping technique or how to avoid exchange maneuvers.

INTRODUCTION: The arteries of bifurcation aneurysms are sometimes so angulated or tortuous that an exchange maneuver is necessary to catheterize them with a balloon or stent delivery catheter. Because of the risk of distal wire perforation associated with exchange maneuvers, we sought to find an alternative technique. METHODS: Our experience shows that a microcatheter tends to preferentially follow a previously placed microcatheter, even if the initial catheterization might be challenging. Accessing an artery with two microcatheters simultaneously may thus be an alternative to an exchange maneuver. Because of this tendency for catheters to behave like sheep following one another, we named this method the sheeping technique (ST). The ST consists of (a) first placing a 1.7 French microcatheter into the division branch requiring balloon or stent protection to straighten the course of the arteries in order to facilitate and (b) positioning in the same artery of a larger and stiffer balloon or stent microcatheter. Once the second balloon or stent microcatheter is in place, the first microcatheter can be pulled back and used to coil the aneurysm. RESULTS: Between January 2009 and December 2012, The ST was successfully used in 208/246 procedures (85%). Conversion to an exchange maneuver was necessary in 38/246 (15%). There were no arterial perforations or ischemic events related to the handling of both microcatheters. CONCLUSION: The sheeping technique may improve safety by replacing the need for an exchange maneuver during difficult balloon- or stent-assisted coiling.

Contrast-enhanced time-resolved 3-D MRA: applications in neurosurgery and interventional neuroradiology.

PURPOSE: The decision-making process in the endovascular treatment of cranial dural AV fistulas and angiomas and their follow-up after treatment is usually based on conventional digital subtraction angiography (DSA). Likewise, acquiring the vascular and hemodynamic information needed for presurgical evaluation of meningiomas may necessitate DSA or different MR-based angiographic methods to assess the arterial displacement, the location of bridging veins and tumor feeders, and the degree of vascularization. New techniques of contrast-enhanced MR angiography (MRA) permit the acquisition of images with high temporal and spatial resolution. The purpose of this study was to evaluate the applicability and clinical use of a newly developed contrast-enhanced 3-D dynamic MRA protocol for neurointerventional and neurosurgical planning and decision making. METHODS: With a 3-T whole-body scanner (Philips Achieva), a 3-D dynamic contrast-enhanced (MultiHance, Bracco) MRA sequence with parallel imaging, and intelligent k-space readout (keyhole and "CENTRA" k-space filling) was added to structural MRI in patients with meningiomas, dural arteriovenous fistulas and pial arteriovenous malformations. The sequence had a temporal resolution of 1.3 s per 3-D volume with a spatial resolution of 0.566x0.566x1.5 mm per voxel in each 3-D volume and lasted 25.2 s. DSA was performed in selected patients following MRI. RESULTS: In patients with arteriovenous fistulas and malformations, MRA allowed the vascular shunt to be identified and correctly classified. Hemodynamic characteristics and venous architecture were clearly demonstrated. Larger feeding arteries could be identified in all patients. In meningiomas, MRA enabled assessment of the displacement of the cerebral arteries, depiction of the tumor feeding vessels, and evaluation of the anatomy of the venous system. The extent of tumor vascularization could be assessed in all patients and correlated with the histopathological findings that indicated hypervascularization. CONCLUSION: High temporal and spatial resolution 3-D MRA may allow correct identification and classification of fistulas and angiomas and help to reduce the number of pre-or postinterventional invasive diagnostic angiograms. This sequence is also helpful for characterizing the degree of vascularization in preoperative evaluation of meningiomas and to select meningiomas suitable for embolization. Displacement of normal arteries and depiction of the venous anatomy can be achieved cost-effectively in a short period of time. The high spatial resolution also permits improved demonstration of the major feeding arteries, which helps to reduce the number of conventional angiograms required for meningioma evaluation.