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BACKGROUND AND PURPOSE: Acute BAO is a devastating neurological condition associated with a poor clinical outcome and a high mortality rate. Recanalization has been identified as a major prognostic factor for good outcome in BAO. Mechanical thrombectomy using retrievable stents is an emerging treatment option for acute stroke. First clinical trials using stent retrievers have shown promising high recanalization rates. However, these studies mainly included large artery occlusions in the anterior circulation with only a few or single cases of BAO. Therefore, the purpose of this study was to evaluate technical feasibility, safety, and efficacy of mechanical thrombectomy using retrievable stent in the treatment of acute BAO. MATERIALS AND METHODS: Fourteen consecutive patients with BAO undergoing endovascular therapy using retrievable stents (Solitaire FR Revascularization Device) were included. Additional multimodal treatment approaches included thromboaspiration, intravenous and/or intra-arterial thrombolysis, and PTA/ permanent stent placement. Recanalization rates after multimodal therapy and stent retrieval were determined. Clinical outcome and mortality were assessed 3 months after treatment. RESULTS: Median patient age was 64.5 years (range 55–85). Median NIHSS score at presentation was 21 (range 5–36). Overall, successful recanalization (TICI 3 or 2b) was achieved in all patients (TICI 3 in 78.6%, 11/14). In 4 patients (28.6%), insufficient recanalization after stent retrieval was due to an underlying atherosclerotic stenosis. Additional deployment of a permanent intracranial stent was performed in 3 patients (21.4%) and PTA alone in 1 patient (7.1%), resulting in final TICI 3 in 1 patient and TICI 2b in 3 patients. Stent retrieval alone was performed in 4 patients (28.6%). Average number of device passes was 1.3 (range 1–3). Median procedure time to maximal recanalization was 47 minutes (range 10–252). No device-related complications or thromboembolic occlusion of a previously unaffected artery occurred. There was no symptomatic intracranial hemorrhage. At 3 months, good functional outcome (mRS 0–2) was observed in 28.6% (4/14); overall mortality was 35.7% (5/14). CONCLUSIONS: A multimodal endovascular approach using retrievable stents in BAO has high recanalization rates, with very low complication rates. Underlying atherothrombotic stenotic lesions of the basilar artery may still necessitate additional permanent stent placement to achieve complete recanalization.

Simple clinical scores to predict large vessel occlusion (LVO) in acute ischemic stroke would be helpful to triage patients in the prehospital phase. We assessed the ability of various combinations of National Institutes of Health Stroke Scale (NIHSS) subitems and published stroke scales (i.e., RACE scale, 3I-SS, sNIHSS-8, sNIHSS-5, sNIHSS-1, mNIHSS, a-NIHSS items profiles A-E, CPSS1, CPSS2, and CPSSS) to predict LVO on CT or MR arteriography in 1085 consecutive patients (39.4 % women, mean age 67.7 years) with anterior circulation strokes within 6 h of symptom onset. 657 patients (61 %) had an occlusion of the internal carotid artery or the M1/M2 segment of the middle cerebral artery. Best cut-off value of the total NIHSS score to predict LVO was 7 (PPV 84.2 %, sensitivity 81.0 %, specificity 76.6 %, NPV 72.4 %, ACC 79.3 %). Receiver operating characteristic curves of various combinations of NIHSS subitems and published scores were equally or less predictive to show LVO than the total NIHSS score. At intersection of sensitivity and specificity curves in all scores, at least 1/5 of patients with LVO were missed. Best odds ratios for LVO among NIHSS subitems were best gaze (9.6, 95 %-CI 6.765-13.632), visual fields (7.0, 95 %-CI 3.981-12.370), motor arms (7.6, 95 %-CI 5.589-10.204), and aphasia/neglect (7.1, 95 %-CI 5.352-9.492). There is a significant correlation between clinical scores based on the NIHSS score and LVO on arteriography. However, if clinically relevant thresholds are applied to the scores, a sizable number of LVOs are missed. Therefore, clinical scores cannot replace vessel imaging.

Background and Purpose— Five randomized controlled trials have consistently shown that mechanical thrombectomy (MT) in addition to best medical treatment (±intravenous tissue-type plasminogen activator) improves outcome after acute ischemic stroke in patients with large artery anterior circulation stroke. Whether direct MT is equally effective as combined intravenous thrombolysis with MT (ie, bridging thrombolysis) remains unclear. Methods— We retrospectively compared clinical and radiological outcomes in 167 bridging patients with 255 patients receiving direct MT because of large artery anterior circulation stroke. We matched all patients from the direct MT group who would have qualified for intravenous tissue-type plasminogen activator with controls from the bridging group, using multivariate and propensity score analyses. Functional independence was defined as modified Rankin Scale score of 0 to 2. Results— From February 2009 to August 2014, 40 patients from the direct MT group would have qualified for bridging thrombolysis but were treated with MT only. Clinical and radiological characteristics did not differ from the bridging cohort, except for higher rates of hypercholesterolemia ( P =0.019), coronary heart disease ( P =0.039), and shorter intervals from symptom onset to endovascular intervention ( P =0.01) in the direct MT group. Functional independence, mortality, and intracerebral hemorrhage rates did not differ ( P >0.1). After multivariate matching analysis outcome in both groups did not differ, except for lower rates of asymptomatic intracerebral hemorrhage ( P =0.023) and lower mortality ( P =0.007) in the direct MT group. Conclusions— In patients with large anterior circulation stroke, direct mechanical intervention seems to be equally effective as bridging thrombolysis. A randomized trial comparing direct MT with bridging therapy is warranted.

Summary Endovascular stroke treatment is a rapidly evolving field in neurointerventions. The article reviews the evolution of the different mechanical thrombolysis and stenting techniques and their working principles for endovascular vessel recanalization and reviews the data on the outcome after acute stroke treatment.

BACKGROUND AND PURPOSE: CBV is a vital perfusion parameter in estimating the viability of brain parenchyma (eg, in cases of ischemic stroke or after interventional vessel occlusion). Recent technologic advances allow parenchymal CBV imaging tableside in the angiography suite just before, during, or after an interventional procedure. The aim of this work was to analyze our preliminary clinical experience with this new imaging tool in different neurovascular interventions. MATERIALS AND METHODS: FPD-CBV measurement was performed on a biplane FPD angiographic system. Eighteen patients (11 women, 7 men) were examined (age range, 18–86 years; median, 58.7 years). In the 10 patients with stroke, the extent of intracranial hypoperfusion was evaluated. The remaining 8 patients had an intracranial hemorrhage; periprocedural CBV was evaluated during the course of interventional treatment. RESULTS: In the 18 cases studied, 23 CBV measurements were performed. Twenty acquisitions were of sufficient diagnostic quality. The remaining 3 acquisitions failed technically, 1 due to motion artifacts and 2 due to injection technique and/or hardware failure. CONCLUSIONS: FPD-CBV measurement in the angiography suite provides a feasible and helpful tool for peri-interventional neuroimaging. It extends the intraprocedural imaging modalities to the level of tissue perfusion. However, the technique has technical limitations and shows room for improvement in the future.

BACKGROUND AND PURPOSE: Retrievable stents combine the high recanalization rate of stents and the capability of removing the thrombus offered by mechanical thrombectomy devices. We hypothesized that retrievable stents shorten time to recanalization in the multimodal approach for endovascular stroke treatment. MATERIALS AND METHODS: Forty consecutive patients with acute ischemic stroke and undergoing endovascular therapy were included. Treatment included thromboaspiration, thrombus disruption, thrombolysis, PTA, and stent placement. In 17 patients, a retrievable stent was used (group A) in addition to multimodal therapy. The remaining 23 patients constituted group B. Baseline characteristics, occlusion sites, urokinase dose, recanalization rate, and time to recanalization were compared between the groups. RESULTS: Median NIHSS scores were higher in group A compared with group B on admission (19 versus 12.5; P = .018) but were not significantly different at day 1 (14 versus 10; P = .6). Intra-arterial thrombolysis was used in significantly fewer patients of group A than group B (53% versus 87%, respectively; P = .017), and median urokinase dose was lower in group A than in group B (250,000 IU versus 700,000 IU; P = .006). Time to recanalization was significantly shorter in group A compared with group B (median time to recanalization 52.5 minutes versus 90 minutes, respectively; P = .001). Recanalization rate was higher in group A than group B (94% versus 78%; P = .17). CONCLUSIONS: Addition of retrievable stents to the multimodal endovascular approach for acute ischemic stroke treatment significantly reduces time to recanalization and further increases the recanalization rate.

A blood clot needs to have the right degree of mechanical, chemical and biological properties to stem the flow of blood and yet to be suitable for lytic enzymes or mechanical thrombectomy so as not to form a thrombotic event. The origin and understanding of these mechanical properties are still not known in detail. Clots are made of a three-dimensional network of fibrin fibers stabilized through ligation with a transglutaminase, factor XIIIa. New methods to achieve information about mechanical properties were established in this work. We performed compressive strength experiments of aged human blood clots. Furthermore after the set up of a new test environment, it was possible to perform tensile strength measurements of aged animal blood clots. Stress strain curves of aged clots were measured and discussed. The viscoelastic properties of the clot material were quantitatively described. This work should make a contribution to a better understanding of the behaviour of aged blood thrombus bulk material and induced mechanical stress. In der Behandlung ischamischer Schlaganfalle sind mechanische, chemische und biologische Eigenschaften von Blutgerinnseln von essentieller Bedeutung und entscheidend uber den Erfolg einer Lyse-Therapie bzw. mechanischer Thrombektomie. Die Einflussfaktoren der Gerinnungsbedingungen auf die mechanischen Eigenschaften sind jedoch bisher noch nicht eingehend untersucht. Aus Schrifttum ist bekannt, dass auf mikrostruktureller Ebene die Blutgerinnsel aus Fibrinfasern, die untereinander in Knotenpunkten verbunden sind und in der Gesamtheit ein dreidimensionales Netzwerk bilden, bestehen. Dabei haben besonders die Faserdicke und die Knotenpunktendichte einen direkten Einfluss auf die mechanischen Eigenschaften eines Thrombus. Im Rahmen dieser Arbeit wurden Druck- und Zugversuche an Thrombus-Proben (hergestellt aus humanem bzw. tierischem Blut) durchgefuhrt und die Messergebnisse hinsichtlich der Gerinnungsbedingungen diskutiert.

Purpose Delayed occlusion time in parent artery occlusion of brain-supplying vessels might carry risk for thromboembolic complications. Vascular plug devices are successfully used in cardiopulmonary and peripheral interventions to occlude high-flow lesions and have been adapted for use in neurointerventions. The purpose of the present study was to experimentally evaluate the immediate occlusion time of the AMPLATZER vascular plug (AVP) II—a second-generation cylindrical, self-expandable, resheathable nitinol wire mesh consisting of three lobes—in the carotid artery. Materials and Methods AVP II devices ( N = 12) 6 mm in diameter (length, 6 mm) were deployed through 6-F guiding catheters in the common carotid arteries of two pigs. After device deployment, angiography was performed to measure the time interval until no contrast agent opacification was visible distal to the AVP II, indicating complete flow cessation and occlusion of the distal vessel. Vessel diameters before deployment and after resheathing of the device were measured. Device navigation, positioning, recapturing, vasospasm, and angiographic signs of vessel injury were assessed. Results The mean time to total flow cessation and occlusion was 57.9 seconds (median, 44 s ± 27 [SD]; range, 26–104 s). Device navigation, positioning, and resheathing were successful in all cases. There was neither significant vasospasm nor vessel injury visible on angiography. Conclusions Application and retrieval of the second-generation AVP II are uncomplicated and the device is able to achieve fast and sufficient cessation of flow in a hemodynamically comparable setting to the human carotid artery, indicating some potential to fill a gap in the neurointerventional tool box.

BACKGROUND AND PURPOSE: The use of self-expanding retrievable stents is an emerging and promising treatment strategy for acute stroke treatment. The concept combines the advantages of stent deployment with immediate flow-restoration and of mechanical thrombectomy with definitive thrombus removal. The present study was performed to gain more knowledge about the principle of combined flow restoration and thrombectomy in an established animal model using radiopaque thrombi evaluating efficiency, thrombus-device interaction and possible complications of the first dedicated flow-restoration and mechanical thrombectomy device. MATERIALS AND METHODS: The Solitaire FR (4 × 20 mm) was evaluated in 15 vessel occlusions in an established animal model in swine. Flow-restoration effect at T0, T5, and T10; recanalization rate after retrieval; thromboembolic events; and complications were assessed. Radiopaque thrombi (10-mm length) were used for visualization of thrombus-device interaction during application and retrieval. RESULTS: Immediate flow restoration was achieved in 80% of occlusions. Mean percentage of recanalization compared with the initial vessel diameter at T0 was 30.8%; at T5, 30.7%; and at T10, 25.4%. Re-occlusion occurred in 20.0% between T0 and T5 and in 13.3% between T5 and T10. Complete recanalization (TICI 3) after retrieval was achieved in 86.7%. In 2 cases (13.3%), partial recanalization was achieved, with the remaining thrombus in a side branch (TICI 2b). No thromboembolic event was observed. The assessment of thrombus-device interaction illustrated the compression of the thrombus against the vessel wall during deployment leading to partial flow restoration. During retrieval, the thrombus was retained by the stent struts even during the passage of vessel curvatures. CONCLUSIONS: The Solitaire FR is a safe and effective combined flow-restoration and thrombectomy device in vivo. Partial flow restoration is achieved by thrombus compression immediately after deployment, but flow restoration decreases afterward until final retrieval results in maximal recanalization.

Duplication of the vertebral arteries is a rare developmental anomaly. We report on an asymmetrical bilateral duplication of the extracranial vertebral arteries which was an incidental finding demonstrated by MR angiography in a patient evaluated for middle cerebral artery stroke and internal carotid stenosis. On the right side two separate origins of the vertebral artery arose directly from the subclavian artery, whereas on the left side one leg originated directly from the aortic arch and the other one from the left proximal subclavian artery. To the best of our knowledge, this is the first report on an asymmetrical bilateral duplication of the origins of the extracranial vertebral arteries. The possible embryologic mechanisms and the possible clinical importance of this previously unreported variant are reviewed.

Object The treatment of complex cerebrovascular or skull base pathological conditions necessitates a microsurgical blood flow preservation or augmentative revascularization procedure as either an adjunctive safety measure or a definitive treatment. The brain is susceptible to ischemia, and procedure-related risks can be minimized by the reduction of occlusion time or the use of a nonocclusive technique. The authors therefore analyzed the feasibility of an automatic device (C-Port xA, Cardica) designed for constructing an end-to-side anastomosis with or without flow interruption for a middle cerebral artery (MCA) bypass in a human cadaveric model and in an in vivo craniotomy simulation model. Methods Four Thiel-fixated human head specimens were prepared using 8 standard pterional craniotomies. The sylvian fissure was opened to access the anterior circulation and in particular the MCA. The length of the individual vessel segments was measured. The C-Port xA was tested on each of the 8 exposures. In addition the C-Port xA was deployed in an in vivo craniotomy simulator model in 10 New Zealand rabbits (a total of 20 anastomoses) by using the abdominal aorta jump graft model. Results Short-term patency was assessed by angiography and histological findings. In all 8 sylvian exposures, construction of an MCA anastomosis with the aid of the C-Port xA was feasible. All 20 jump graft anastomoses performed in the in vivo craniotomy simulator were found to be patent. Conclusions The anatomical studies as well as the in vivo craniotomy simulation studies demonstrated that the dimensions of the automated end-to-side anastomosis device are suitable for an extracranial–intracranial high-flow bypass on the MCA. Further miniaturization and special adaptation of this device would allow bypass procedures to more proximal intracranial vessels.

GOALS OF WORK: Long-term outcomes of osteosarcoma have dramatically improved with the use of modern combination therapies. Such aggressive treatments, however, entail chronic complications. In the present study, we assessed the functional, psychological, and familial status of long-term survivors of osteosarcoma treated at our institution. MATERIALS AND METHODS: Fifteen long-term survivors of osteosarcoma were evaluated for functional and psychological sequelae. Functional assessment was based on a method described by Enneking et al. Psychological assessment was based on General Health Questionnaire 28, Inventory Scale for Traumatic Neurosis, and Family System Test. MAIN RESULTS: Ten patients showed mild functional impairments; only five patients were handicapped more seriously. Depressive symptoms were diagnosed in four patients. A total of six patients revealed unbalanced family structures, including three of the four patients with depressive symptoms, all four patients with symptoms of posttraumatic stress disorder, and five of seven patients who showed poor emotional acceptance. CONCLUSIONS: Osteosarcoma survivors will generally recover good functional performance. Only a minority of them remain seriously impaired. One third of the patients present depressive symptoms and posttraumatic stress disorder. Poor coping is closely associated with unbalanced family structures. Therefore, the psychological and familial situation of patients with newly diagnosed osteosarcoma should be carefully assessed.

Clinical trials have shown a beneficial effect of mechanical thrombectomy in acute ischemic stroke patients treated within six up to even 12 h after symptom onset. This treatment was already performed in selected hospitals in Belgium before completion of the randomized controlled trials. Outcome data on these procedures in Belgium have not been published. We performed a retrospective multicenter study of all patients with acute ischemic stroke treated with mechanical endovascular therapy in four hospitals in Belgium. Clinical outcomes, as measured by the modified Rankin Scale (mRS), site of arterial occlusion, reperfusion and the association between these variables were studied. The study included 80 patients: 65 patients with an occlusion in the anterior circulation and 15 with an occlusion in the posterior circulation. Good functional outcome (GFO) rates, defined as mRS 0-2 at 90 days, were 42 % in all patients, 44 % in anterior circulation stroke and 34 % in posterior circulation stroke. Reperfusion was achieved in 78 % of patients; more (100 %) in patients with posterior compared to patients with anterior circulation stroke (72 %; p = 0.02). The rate of GFO was greater in patients with reperfusion versus patients in whom reperfusion was not achieved (adjusted OR 8.2, 95 % CI 2.0-34.2). Symptomatic intracerebral hemorrhage was documented in 5 % of all patients. Endovascular treatment with mechanical devices for acute ischemic stroke in Belgium results in GFO and reperfusion rates similar to recently published results in the endovascular-treated arms of randomized clinical trials. Rates of symptomatic intracranial hemorrhage are low and comparable to other cohort studies and clinical trials. ispartof: Acta Neurologica Belgica vol:116 issue:1 pages:7-14 ispartof: location:Italy status: published

Background: The aim of this study was to analyze the influence of the location of middle cerebral artery (MCA) occlusion on recanalization, complications and outcome after endovascular therapy. Methods: Four-hundred sixty-four patients with acute MCA occlusions were treated with endovascular therapy. Results: Two-hundred ninety-three patients had M1 occlusions, 116 had M2, and 55 had M3/4 occlusions. Partial or complete recanalization was more frequently achieved in M1 (76.8%) than in M2 (59.1%) or M3/4 (47.3%, p < 0.001) occlusions, but favorable outcome (modified Rankin Scale 0-2) was less frequent in M1 (50.9%) than M2 (63.7%) or M3/4 (72.7%, p = 0.018) occlusions. Symptomatic intracerebral hemorrhage (ICH) did not differ between occlusion sites, but asymptomatic ICH was more common in M1 (22.6%) than in M2 occlusions (8.6%, p = 0.003). Recanalization was associated with favorable outcome in M1 (p < 0.001) and proximal M2 (p = 0.003) but not in distal M2 or M3/4 occlusions. Conclusions: Recanalization with endovascular therapy was more frequently achieved in patients with proximal than distal MCA occlusions, but recanalization was associated with favorable outcome only in M1 and proximal M2 occlusions. Outcome was better with distal than proximal occlusions. This study shows that recanalization can be used as a surrogate marker for clinical outcome only in patients with proximal occlusions.

BACKGROUND AND PURPOSE: The prevalence and clinical importance of primarily fragmented thrombi in patients with acute ischemic stroke remains elusive. Whole-brain SWI was used to detect multiple thrombus fragments, and their clinical significance was analyzed. MATERIALS AND METHODS: Pretreatment SWI was analyzed for the presence of a single intracranial thrombus or multiple intracranial thrombi. Associations with baseline clinical characteristics, complications, and clinical outcome were studied. RESULTS: Single intracranial thrombi were detected in 300 (92.6%), and multiple thrombi, in 24 of 324 patients (7.4%). In 23 patients with multiple thrombi, all thrombus fragments were located in the vascular territory distal to the primary occluding thrombus; in 1 patient, thrombi were found both in the anterior and posterior circulation. Only a minority of thrombus fragments were detected on TOF-MRA, first-pass gadolinium-enhanced MRA, or DSA. Patients with multiple intracranial thrombi presented with more severe symptoms (median NIHSS scores, 15 versus 11; P = .014) and larger ischemic areas (median DWI ASPECTS, 5 versus 7; P = .006); good collaterals, rated on DSA, were fewer than those in patients with a single thrombus (21.1% versus 44.2%, P = .051). The presence of multiple thrombi was a predictor of unfavorable outcome at 3 months ( P = .040; OR, 0.251; 95% CI, 0.067–0.939). CONCLUSIONS: Patients with multiple intracranial thrombus fragments constitute a small subgroup of patients with stroke with a worse outcome than patients with single thrombi.

INTRODUCTION Diagnostic tools to show emboli reliably and protection techniques against embolization when employing stent retrievers are necessary to improve endovascular stroke therapy. The aim of the present study was to investigate iatrogenic emboli using susceptibility-weighted imaging (SWI) in an open series of patients who had been treated with stent retriever thrombectomy using emboli protection techniques. METHODS Patients with anterior circulation stroke examined with MRI before and after stent retriever thrombectomy were assessed for iatrogenic embolic events. Thrombectomy was performed in flow arrest and under aspiration using a balloon-mounted guiding catheter, a distal access catheter, or both. RESULTS In 13 of 57 patients (22.8 %) post-interventional SWI sequences detected 16 microemboli. Three of them were associated with small ischemic lesions on diffusion-weighted imaging (DWI). None of the microemboli were located in a new vascular territory, none showed clinical signs, and all 13 patients have been rated as Thrombolysis in Cerebral Infarction (TICI) 2b (n = 3) or 3 (n = 10). Retrospective reevaluation of the digital subtraction angiography (DSA) detected discrete flow stagnation nearby the iatrogenic microemboli in four patients with a positive persistent collateral sign in one. CONCLUSION Our study demonstrates two things: First, SWI seems to be more sensitive to detect emboli than DWI and DSA and, second, proximal or distal protected stent retriever thrombectomy seems to prevent iatrogenic embolization into new vascular territories during retraction of the thrombus, but not downstream during mobilization of the thrombus. Both techniques should be investigated and refined further.

BACKGROUND Recovery after arterial ischaemic stroke is known to largely depend on the plastic properties of the brain. The present study examines changes in the network topography of the developing brain after stroke. Effects of brain damage are best assessed by examining entire networks rather than single sites of structural lesions. Relating these changes to post-stroke neuropsychological variables and motor abilities will improve understanding of functional plasticity after stroke. Inclusion of healthy controls will provide additional insight into children's normal brain development. Resting state functional magnetic resonance imaging is a valid approach to topographically investigate the reorganisation of functional networks after a brain lesion. Transcranial magnetic stimulation provides complementary output information. This study will investigate functional reorganisation after paediatric arterial ischaemic stroke by means of resting state functional magnetic resonance imaging and transcranial magnetic stimulation in a cross-sectional plus longitudinal study design. The general aim of this study is to better understand neuroplasticity of the developing brain after stroke in order to develop more efficacious therapy and to improve the post-stroke functional outcome. METHODS The cross-sectional part of the study will investigate the functional cerebral networks of 35 children with chronic arterial ischaemic stroke (time of the lesion >2 years). In the longitudinal part, 15 children with acute arterial ischaemic stroke (shortly after the acute phase of the stroke) will be included and investigations will be performed 3 times within the subsequent 9 months. We will also recruit 50 healthy controls, matched for age and sex. The neuroimaging and neurophysiological data will be correlated with neuropsychological and neurological variables. DISCUSSION This study is the first to combine resting state functional magnetic resonance imaging and transcranial magnetic stimulation in a paediatric population diagnosed with arterial ischaemic stroke. Thus, this study has the potential to uniquely contribute to the understanding of neuronal plasticity in the brains of healthy children and those with acute or chronic brain injury. It is expected that the results will lead to the development of optimal interventions after arterial ischaemic stroke.

Background and Purpose— Lesion volume on diffusion-weighted magnetic resonance imaging (DWI) before acute stroke therapy is a predictor of outcome. Therefore, patients with large volumes are often excluded from therapy. The aim of this study was to analyze the impact of endovascular treatment in patients with large DWI lesion volumes (>70 mL). Methods— Three hundred seventy-two patients with middle cerebral or internal carotid artery occlusions examined with magnetic resonance imaging before treatment since 2004 were included. Baseline data and 3 months outcome were recorded prospectively. DWI lesion volumes were measured semiautomatically. Results— One hundred five patients had lesions >70 mL. Overall, the volume of DWI lesions was an independent predictor of unfavorable outcome, survival, and symptomatic intracerebral hemorrhage ( P 70 mL, 11 of 31 (35.5%) reached favorable outcome (modified Rankin scale score, 0–2) after thrombolysis in cerebral infarction 2b-3 reperfusion in contrast to 3 of 35 (8.6%) after thrombolysis in cerebral infarction 0-2a reperfusion ( P =0.014). Reperfusion success, patient age, and DWI lesion volume were independent predictors of outcome in patients with DWI lesions >70 mL. Thirteen of 66 (19.7%) patients with lesions >70 mL had symptomatic intracerebral hemorrhage with a trend for reduced risk with avoidance of thrombolytic agents. Conclusions— There was a growing risk for poor outcome and symptomatic intracerebral hemorrhage with increasing pretreatment DWI lesion volumes. Nevertheless, favorable outcome was achieved in every third patient with DWI lesions >70 mL after successful endovascular reperfusion, whereas after poor or failed reperfusion, outcome was favorable in only every 12th patient. Therefore, endovascular treatment might be considered in patients with large DWI lesions, especially in younger patients.

We present a 63 year old man with new onset of fluctuating headache and behavioural changes showing marked inhibition and disorientation. After non invasive and invasive diagnostics an isolated cerebral vasculitis was found. Key results have been found in cerebral MRI and cerebral digital subtraction angiography with irregularities of vessel calibre of the intracerebral arteries. During treatment with high-dose corticosteroid therapy and Cyclophosphamid pulse therapy qualitative disorders and headache rapidly regressed. We discuss differential diagnosis of secondary headache, etiology of cerebral vasculitides, diagnostic challenge and therapy in isolated cerebral vasculitis.Wir präsentieren einen 63-jährigen Patienten mit neu manifesten fluktuierenden Kopfschmerzen sowie Wesensveränderung bei sonst unauffälligem somatischem Befund. Nach nicht-invasiver und invasiver Diagnostik fand sich ursächlich eine isoliert zerebrale Vaskulitis. Wegweisend war nach breiter differenzialdiagnostischer Abklärung die MR-Angiographie und die digitale zerebrale Subtraktionsangiographie mit Nachweis von Kaliberschwankungen der intrazerebralen Gefässe. Unter hochdosierter Kortikosteroidtherapie sowie Cyclophosphamid-Pulstherapie kam es zur raschen Regredienz der qualitativen Bewusstseinsstörungen und Kopfschmerzen. Wir diskutieren Differenzialdiagnosen sekundärer Kopfschmerzen, Ätiologien zerebraler Vaskulitiden und die diagnostische Herausforderung sowie Therapie einer isolierten zerebralen Vaskulitis.

Elderly patients generally experience less favorable outcomes and higher mortality after acute stroke than younger patients. The aim of this study was to analyze the influence of age on outcome and safety after endovascular therapy in a large cohort of patients aged between 20 and 90 years. We prospectively acquired data of 1,000 stroke patients treated with endovascular therapy at a single center. Logistic regression analysis was performed to determine predictors of outcome and linear regression analysis to evaluate the association of age and outcome after 3 months. Younger age was an independent predictor of favorable outcome (OR 0.954, p < 0.001) and survival (OR 0.947, p < 0.001) in multivariate regression analysis. There was a linear relationship between age and outcome. Ever increase in 26 years of age was associated with an increase in the modified Rankin Scale of 1 point (p < 0.001). However, increasing age was not a risk factor for symptomatic (p = 0.086) or asymptomatic (p = 0.674) intracerebral hemorrhage and did not influence recanalization success (p = 0.674). Advancing age was associated with a decline of favorable outcomes and survival after endovascular therapy. This decline was linear from age 20 to 90 years, but was not related to lower recanalization rates or higher bleeding risk in the elderly. The efficacy of endovascular stroke therapy seems to be preserved also in the elderly and other factors than efficacy of endovascular therapy such as decreased plasticity are likely to explain the worse outcome with advancing age.

Background and Purpose— Stent retrievers have become an important tool for the treatment of acute ischemic stroke. The aim of this study was to analyze outcome and complications in a large cohort of patients with stroke treated with the Solitaire stent retriever. The study also included patients who did not meet standard inclusion criteria for endovascular treatment: low or high baseline National Institutes of Health Stroke Scale score, ≥80 years of age, extensive ischemic signs in middle cerebral artery territory, and time from symptom onset to endovascular intervention >8 hours. Methods— Consecutive patients with acute anterior circulation stroke treated with the Solitaire FR were analyzed. Data on characteristics of endovascular interventions, complications, and clinical outcome were collected prospectively. Patients who met standard inclusion criteria were compared with those who did not. Results— A total of 227 patients were included. Mean age was 68.2±14.7 years, and median National Institutes of Health Stroke Scale score on admission was 16 (range, 2–36). Reperfusion was successful (thrombolysis in cerebral infarction, 2b–3) in 70.9%. Outcome was favorable (modified Rankin Scale, 0–2) in 57.7% of patients who met standard inclusion criteria and 30.3% of those who did not. The rates for symptomatic intracranial hemorrhage were 3.7% and 13.1%, for death 11.4% and 33.8%, and for symptomatic intraprocedural complications 2.5% and 4.8%, respectively. Conclusions— Patients

Fenestration of the basilar artery is infrequently seen and is often associated with aneurysm formation. We describe a case of angiographically confirmed growing vertebrobasilar aneurysm associated with a proximal basilar artery fenestration over 10 years with rupture and consecutive endovascular treatment using Guglielmi detachable coils (GDC).

BACKGROUND Intraoperatively fabricated polymethylmethacrylate (PMMA) implants based on computer-designed moulds were used to improve cosmetic results after hard tissue replacement. To assess the implant's cosmetic and functional results we performed both subjective and objective assessments. METHODS This retrospective analysis was performed using a cohort of 28 patients who received PMMA implants between February 2009 and March 2012. The cosmetic and functional results were assessed using a patient questionnaire. Furthermore an objective volumetric subtraction score (0-100) was applied and implant thickness, as well as gaps and tiers, were measured. RESULTS Patients mainly judged their cosmetic result as "good". Two of the 28 patients found their cosmetic result unfavourable. The functional result and stability was mainly judged to be good. Measurements of implant thickness showed a very high correlation with the thickness of the contralateral bone. Volumetric subtraction led to a median quality of 80 on a scale from 0 to 100. Median gaps around the margins of the implant were 1.5 mm parietally, 1.7 mm frontally and 3.5 mm fronto-orbitally, and median tiers were 1.2 mm, 0 mm and 0 mm respectively. The overall rate of surgical revisions was 10.7 % (three patients). Two patients suffered from wound healing disturbances (7.1 %). The overall complication rate was comparable to other reports in the literature. CONCLUSIONS Implantation of intraoperatively fabricated patient-specific moulded implants is a cost-effective and safe technique leading to good clinical results with a low complication rate.

Background and Purpose— There is some controversy on the association of the National Institutes of Health Stroke Scale (NIHSS) score to predict arterial occlusion on MR arteriography and CT arteriography in acute stroke. Methods— We analyzed NIHSS scores and arteriographic findings in 2152 patients (35.4% women, mean age 66±14 years) with acute anterior or posterior circulation strokes. Results— The study included 1603 patients examined with MR arteriography and 549 with CT arteriography. Of those, 1043 patients (48.5%; median NIHSS score 5, median time to clinical assessment 179 minutes) showed an occlusion, 887 in the anterior (median NIHSS score 7/0–31), and 156 in the posterior circulation (median NIHSS score 3/0–32). Eight hundred sixty visualized occlusions (82.5%) were located centrally (ie, in the basilar, intracranial vertebral, internal carotid artery, or M1/M2 segment of the middle cerebral artery). NIHSS scores turned out to be predictive for any vessel occlusions in the anterior circulation. Best cut-off values within 3 hours after symptom onset were NIHSS scores ≥9 (positive predictive value 86.4%) and NIHSS scores ≥7 within >3 to 6 hours (positive predictive value 84.4%). Patients with central occlusions presenting within 3 hours had NIHSS scores Conclusions— There is a significant association of NIHSS scores and vessel occlusions in patients with anterior circulation strokes. This association is best within the first hours after symptom onset. Thereafter and in the posterior circulation the association is poor.

The goal of acute stroke treatment with intravenous thrombolysis or endovascular recanalization techniques is to rescue the penumbral tissue. Therefore, knowing the factors that influence the loss of penumbral tissue is of major interest. In this study we aimed to identify factors that determine the evolution of the penumbra in patients with proximal (M1 or M2) middle cerebral artery occlusion. Among these factors collaterals as seen on angiography were of special interest. Forty-four patients were included in this analysis. They had all received endovascular therapy and at least minimal reperfusion was achieved. Their penumbra was assessed with perfusion- and diffusion-weighted imaging. Perfusion-weighted imaging volumes were defined by circular singular value decomposition deconvolution maps (Tmax > 6 s) and results were compared with volumes obtained with non-deconvolved maps (time to peak > 4 s). Loss of penumbral volume was defined as difference of post- minus pretreatment diffusion-weighted imaging volumes and calculated in per cent of pretreatment penumbral volume. Correlations between baseline characteristics, reperfusion, collaterals, time to reperfusion and penumbral volume loss were assessed using analysis of covariance. Collaterals (P = 0.021), reperfusion (P = 0.003) and their interaction (P = 0.031) independently influenced penumbral tissue loss, but not time from magnetic resonance (P = 0.254) or from symptom onset (P = 0.360) to reperfusion. Good collaterals markedly slowed down and reduced the penumbra loss: in patients with thrombolysis in cerebral infarction 2 b-3 reperfusion and without any haemorrhage, 27% of the penumbra was lost with 8.9 ml/h with grade 0 collaterals, whereas 11% with 3.4 ml/h were lost with grade 1 collaterals. With grade 2 collaterals the penumbral volume change was -2% with -1.5 ml/h, indicating an overall diffusion-weighted imaging lesion reversal. We conclude that collaterals and reperfusion are the main factors determining loss of penumbral tissue in patients with middle cerebral artery occlusions. Collaterals markedly reduce and slow down penumbra loss. In patients with good collaterals, time to successful reperfusion accounts only for a minor fraction of penumbra loss. These results support the hypothesis that good collaterals extend the time window for acute stroke treatment.

Background and purpose Endovascular therapy is used increasingly for treatment of acute symptomatic internal carotid artery (ICA) occlusion, although randomized trials are lacking. Predictors of outcome are therefore of special interest. Methods From 1992 to 2010 we treated 201 patients with acute ICA occlusion with intra-arterial pharmacological thrombolysis (32), endovascular mechanical therapy (78) or a combination of both (91). All data were assessed prospectively. Results There were 76/38% patients with tandem occlusions [ICA plus middle (MCA) or anterior cerebral arteries (ACA)], 18/9% without concomitant occlusions of major intracranial arteries (ICA plus branch occlusion) and 107/53% with functional ICA-T occlusions (ICA plus MCA and ACA). Median baseline National Institute of Health Stroke Scale (NIHSS) score was 17. Good recanalization (Thrombolysis in Myocardial Infarction 2–3) was achieved in (157/201) 78% patients and good reperfusion (Thrombolysis in Cerebral Infarction 2–3) in (151/182) 83%. Better recanalization rates were obtained with mechanical approaches, with/without thrombolytics (78/91 = 86% and 64/78 = 82%) compared with pharmacological thrombolysis only (15/32 = 47%; P

BACKGROUND AND PURPOSE: Conventional platinum coils cause imaging artifacts that reduce imaging quality and therefore impair imaging interpretation on intraprocedural or noninvasive follow-up imaging. The purpose of this study was to evaluate imaging characteristics and artifact production of polymeric coils compared with standard platinum coils in vitro and in vivo. MATERIALS AND METHODS: Polymeric coils and standard platinum coils were evaluated in vitro with the use of 2 identical silicon aneurysm models coiled with a packing attenuation of 20% each. DSA, flat panel CT, CT, and MR imaging were performed. In vivo evaluation of imaging characteristics of polymeric coils was performed in experimentally created rabbit carotid bifurcation aneurysms. DSA, CT/CTA, and MR imaging were performed after endovascular treatment of the aneurysms. Images were evaluated regarding visibility of individual coils, coil mass, artifact production, and visibility of residual flow within the aneurysm. RESULTS: Overall, in vitro and in vivo imaging showed relevantly reduced artifact production of polymeric coils in all imaging modalities compared with standard platinum coils. Image quality of CT and MR imaging was improved with the use of polymeric coils, which permitted enhanced depiction of individual coil loops and residual aneurysm lumen as well as the peri-aneurysmal area. Remarkably, CT images demonstrated considerably improved image quality with only minor artifacts compared with standard coils. On DSA, polymeric coils showed transparency and allowed visualization of superimposed vessel structures. CONCLUSIONS: This initial experimental study showed improved imaging quality with the use of polymeric coils compared with standard platinum coils in all imaging modalities. This might be advantageous for improved intraprocedural imaging for the detection of complications and posttreatment noninvasive follow-up imaging.

BACKGROUND AND PURPOSE: Currently, several new stent retriever devices for acute stroke treatment are under development and early clinical evaluation. Preclinical testing under standardized conditions is an important first step to evaluate the technical performance and potential of these devices. The aim of this study was to evaluate the immediate recanalization effect, recanalization efficacy, thrombus-device interaction, and safety of a new stent retriever intended for thrombectomy in patients with acute stroke. MATERIAL AND METHODS: The pREset thrombectomy device (4 × 20 mm) was evaluated in 16 vessel occlusions in an established swine model. Radiopaque thrombi (10-mm length) were used for visualization of thrombus-device interaction during application and retrieval. Flow-restoration effect immediately after deployment and after 5-minute embedding time before retrieval, recanalization rate after retrieval, thromboembolic events, and complications were assessed. High-resolution FPCT was performed to illustrate thrombus-device interaction during the embedding time. RESULTS: Immediate flow restoration was achieved in 75% of occlusions. An increase or stable percentage of recanalizations during embedding time before retrieval was seen in 56.3%; a decrease, in 12.5%; reocclusion of a previously recanalized vessel, in 18.8%; and no recanalization effect at all, in 12.5%. Complete recanalization (TICI 3) after retrieval was achieved in 93.8%; partial recanalization (TICI 2b), in 6.2%. No distal thromboembolic events were observed. High-resolution FPCT illustrated entrapment of the thrombus between the stent struts and compression against the contralateral vessel wall, leading to partial flow restoration. During retrieval, the thrombus was retained in a straight position within the stent struts. CONCLUSIONS: In this experimental study, the pREset thrombus retriever showed a high recanalization rate in vivo. High-resolution FPCT allows detailed illustration of the thrombus-device interaction during embedding time and is advocated as an add-on tool to the animal model used in this study.

Introduction Les dissections de la carotide interne (DACI) sont une cause frequente d’accident ischemique, particulierement chez l’adulte jeune, et peuvent etre responsables d’occlusion en tandem (occlusion cervicale par hematome intramural et embole intracrânien proximal). De tres mauvais pronostic en cas de traitement par thrombolyse intraveineuse seule et souvent exclu des essais cliniques d’evaluation de la thrombectomie, l’approche endovasculaire reste peu rapportee dans la litterature. Nous presentons ici les resultats multicentriques de la prise en charge a la phase aigue d’occlusions en tandems secondaires a une dissection de l’artere carotide interne cervicale. Patients et methodes A partir des bases de donnees de prospective de deux centres hospitaliers, nous avons etudie les patients avec occlusion arterielle de circulation anterieure ayant ete traites par voie endovasculaire entre aout 2009 et avril 2013. Parmi eux, nous avons particulierement etudie ceux pris en charge pour occlusion en tandem secondaire a une DACI. L’indication du traitement etait retenue selon le delai depuis le debut des symptomes, la severite du deficit neurologique (score NIHSS) et l’imagerie en urgence. La procedure de revascularisation etait dite retrograde, c’est-a-dire distale puis proximale. Elle consistait en une thrombectomie mecanique intracrânienne par stentriever apres catheterisme triaxial. En suivant, a la discretion de l’operateur, le traitement de la dissection pouvait etre realise par stenting . Le score TICI de revascularisation intracrânienne et le statut clinique (mRS) a 3 mois etaient evalues pour chaque patient. Resultats Trente-quatre patients avec occlusion en tandem par DACI ont ete traites durant la periode selectionnee. L’âge moyen etait 52,5 ans, le NIHSS moyen 17,29 (± 6,23) et le delai moyen entre debut des symptomes et ponction etait de 215,8 minutes (± 66,07). Le traitement permettait une recanalisation complete TICI 2b/3 dans 21 cas (soit 67,65 %). Vingt et un patients (67,65 %) ont presente une evolution favorable (mRS ≤ 2 a 3 mois). Quinze patients (44,12 %) ont beneficie d’un stenting carotidien cervical lors de la procedure de revascularisation. Deux remaniements hemorragiques significatifs ont ete observes dans notre serie (5,9 %). Conclusion La strategie de revascularisation mecanique par approche specifique « distale-a-proximale » en cas de dissection carotidienne avec occlusion intracrânienne est assortie d’un taux de recanalisation intracrânien eleve avec une evolution clinique favorable (67,65 % mRS ≤ 2). Cette methode permet de prendre une decision coherente, dans un second temps operatoire, quant au stenting carotidien cervical.

Acute ischemic stroke is one of the major sources of morbidity and mortality in the industrialized countries. The lifetime risk of stroke is estimated to be 1 in 5 for middle-aged women and 1 in 6 for men according to the Framingham Study.1 Outcome depends on the length of time between onset of symptoms and revascularization, the recanalization rate, and on whether or not intracranial hemorrhage occurs.2 A meta-analysis of 52 studies on thrombolysis outcome in 2066 patients showed that the chance of an independent life after stroke increases 4.4 times for patients with successful recanalization compared with patients without recanalization; mortality rate decreases 4-fold.2 Intravenously administered tissue plasminogen activator (IV tPA) and local intra-arterial thrombolysis (IAT) have both been shown to improve patient outcome. However, the time window for treatment and the recanalization rate of both approaches are limited,3–5 and the application of thrombolytic drugs increases the risk of symptomatic intracranial hemorrhage (sICH).6 The success of recanalization, furthermore, depends on the occlusion site; proximal occlusions of large vessels such as the internal carotid artery have a poor recanalization rate after either IV tPA or IAT.4,5 Recent studies have examined whether mechanical recanalization techniques can accelerate the process of recanalization, increase the recanalization rate, and even expand the window of opportunity. This article describes the evolution of the different mechanical thrombolysis and stenting techniques and their working principles for endovascular vessel recanalization and reviews the data on the outcome after acute stroke treatment. The various techniques and approaches for mechanical thrombolysis (MT) can be divided into 3 categories: thrombus disruption, immediate flow restoration with self-expandable stents, and thrombectomy. According to Pro-Urokinase for Acute Cerebral Thromboembolism-2 (PROACT II), IAT consists of local application of the fibrinolytic drug at the proximal surface …

Mechanical thrombectomy is increasingly applied during the treatment of acute stroke. Various devices have been advocated with different sites of force effect at the thrombus. The purpose of this study was to evaluate the angiographic route of passing systematically and therefore to assess the site of deployment of mechanical devices in correlation to the thrombus in interventional stroke treatment. Twenty-one consecutive patients with endovascular treatment for acute ischemic stroke with 26 passing procedures were evaluated prospectively. Occlusion site was the M1-segment in 17 cases (65.4%), ICA termination in five cases (19.2%), M2-segment in two cases (7.7%), the A2-segment in one case (3.8%) and basilar artery in one case (3.8%). On angiographic images the microwire and microcatheter passage was evaluated by illustrating the entry point and course across the occlusion site in relation to the thrombus in different projections and in correlation to the recanalisation result. Results were correlated to the origin of the thrombi according to the TOAST criteria. In all cases the point of entry to the occlusion site was delineated laterally to the thrombus in at least one projection. The course of the wire across the occluded segment in relation to the thrombus was found to be laterally in 22 procedures (84.6%). In the majority of M1-occlusions (12/17, 70.6%) the passage was found in the cranial aspect of the thrombus. In four procedures (15.4%) angiograms in different projections did not unequivocally confirm a passage laterally to the thrombus. The route of passing the thrombus was independent of thrombus origin according to the TOAST criteria. In the majority of cases the complete route of passing the occlusion site was visualized angiographically. Entrance of the microwire and microcatheter at proximal surface of the thrombus takes place laterally to the thrombus and accordingly the passage takes place between the thrombus and the vessel wall independent of thrombus origin. A penetration of the thrombus was not observed. This route of passing has implications on deployment and transmission of force in relation to the thrombus in mechanical approaches and consequently on the development of retrieval devices.

Background: Experimental tissue fusion benefits from the selective heating of superparamagnetic iron oxide nanoparticles (SPIONs) under high frequency irradiation. However, the metabolic pathways of SPIONs for tissue fusion remain unknown. Hence, the goal of this in vivo study was to analyze the distribution of SPIONs in different organs by means of magnetic resonance imaging (MRI) and histological analysis after a SPION-containing patch implantation. Methods: SPION-containing patches were implanted in rats. Three animal groups were studied histologically over six months. Degradation assessment of the SPION-albumin patch was performed in vivo using MRI for iron content localization and biodistribution. Results: No SPION degradation or accumulation into the reticuloendothelial system was detected by MRI, MRI relaxometry, or histology, outside the area of the implantation patch. Concentrations from 0.01 μg/mL to 25 μg/mL were found to be hyperintense in T1-like gradient echo sequences. The best differentiation of concentrations was found in T2 relaxometry, susceptibility-sensitive gradient echo sequences, and in high repetition time T2 images. Qualitative and semiquantitative visualization of small concentrations and accumulation of SPIONs by MRI are feasible. In histological liver samples, Kupffer cells were significantly correlated with postimplantation time, but no differences were observed between sham-treated and induction/no induction groups. Transmission electron microscopy showed local uptake of SPIONs in macrophages and cells of the reticuloendothelial system. Apoptosis staining using caspase showed no increased toxicity compared with sham-treated tissue. Implanted SPION patches were relatively inert with slow, progressive local degradation over the six-month period. No distant structural alterations in the studied tissue could be observed. Conclusion: Systemic bioavailability may play a role in specific SPION implant toxicity and therefore the local degradation process is a further aspect to be assessed in future studies., Video abstract Video

BACKGROUND AND PURPOSE: Angioplasty and stenting of the IA have been reported with high technical and clinical success rates, low complication rates and good mid-term patency rates. Different antegrade or retrograde endovascular catheter-based approaches and combinations with surgical exposure of the CCA are used. The purpose of this study was to determine safety, efficacy and mid-term clinical and radiological outcome of the stent-assisted treatment of atherosclerotic stenotic disease of the IA with special focus on the different technical approaches. MATERIALS AND METHODS: Between 1996 and 2008, 18 patients (12 men, 6 women) with symptomatic high-grade stenosis (>80%) of the IA were treated with endovascular stent placement. Their mean age was 60.4 years (range, 48–78 years). Mean angiographic and clinical follow-up was 2.7 years (range, 0.3–9.1 years). Clinical follow-up was performed by using the mRS at hospital discharge, routine follow-up controls, and a questionnaire. In 11 patients, a percutaneous approach was used. In 7 patients, the lesions were accessed retrogradely through a cervical cut-down with common carotid arteriotomy. In 2 patients, a simultaneous ipsilateral carotid endarterectomy was performed. RESULTS: In all patients, primary stent placement was performed. There were 2 procedure-related transient complications (11.1%) due to cerebral embolism without permanent morbidity or mortality. During the follow-up, all patients showed improvement of the preprocedural symptoms. At the latest clinical follow-up (mean, 2.7 years), all patients showed an excellent or good outcome (mRS, 0 or 1). In 2 patients (11.1%), a secondary stent placement was needed due to a significant symptomatic in-stent stenosis. CONCLUSIONS: Percutaneous and open retrograde stenting of high-grade stenosis of the IA is a viable less invasive alternatives to open bypass surgery with good midterm clinical results and patency rates.

Background and Purpose— Intra-arterial thrombolysis can be used for treatment of basilar artery occlusion. Predictors of outcome before initiation of treatment are of special interest. Methods— From 1992 to 2010, we treated 106 consecutive patients with basilar artery occlusion with intra-arterial thrombolysis. Baseline characteristics, treatment, clinical course, and 3-month and long-term outcomes (≥12 months) were assessed. Outcome parameters were vessel recanalization after treatment, complications, modified Rankin scale (mRS) score, and mortality after 3 months and in the long-term. Results— At 3 months, clinical outcome was good (mRS score, 0–2) in 33.0% of the patients and moderate (mRS score, 3) in 11.3%. Mortality was 40.6%. Partial or complete recanalization was achieved in 69.8% of the patients, and symptomatic intracranial hemorrhage occurred in 1 patient (0.9%). Between 3-month and long-term follow-up, 22 survivors (40.8%) showed clinical improvement of at least 1 point on the mRS score, 29 (53.7%) were functionally unchanged, and 3 (5.7%) showed functional worsening ( P P =0.028). Low baseline National Institutes of Health Stroke Scale score was identified as a predictor of good or moderate clinical outcome ( P P =0.001) at 3 months, and younger age was identified as an additional predictor of survival ( P =0.012). For prediction of long-term clinical outcome, age was also an independent predictor ( P =0.018). Conclusions— In our series, intra-arterial thrombolysis as treatment of basilar artery occlusion was safe. National Institutes of Health Stroke Scale score at admission and age were identified as predictors of outcome, and these predictors should be considered for treatment allocation in future randomized trials.

Introduction The optimal management of patients with symptomatic severe ostial vertebral artery stenosis (OVAS) is currently unclear. We analyzed the long-term outcome of consecutive patients with OVAS who received either medical treatment (MT) or vertebral artery stenting (VAS).

Introduction Preoperative mapping of the arterial spinal supply prior to thoracoabdominal aortic aneurysm repair is highly relevant because of high risk for postoperative ischemic spinal cord injuries such as paraparesis or paraplegia. Methods Twenty-four consecutive patients prior to surgical thoracoabdominal aortic aneurysm repair were investigated. All patients underwent steady-state MR angiography (MRA) of the spinal vasculature with 3-T MRI. The sequence used was a steady-state coronary 3D FLASH with 0.7-mm isotropic voxels. MRA was performed using an intravasal contrast agent. Studies were evaluated by three readers including delineation of arterial spinal supply including both aortic origin and spinal canal entry by three readers. Results Identification and localization of the Adamkiewicz artery and its spinal canal entry was successful in all patients. Overall depiction of the vascular anatomy was graded as very good in 3 (12.5%), good in 14 (58.4%), sufficient in 5 (20.8%), and poor in 2 (8.3%) patients. Depiction of segmental artery aortic exit level was graded as good in 6 (25.0%), sufficient in 10 (41.7%), poor in 4 (16.7%) and not identifiable in 4 (16.7%) patients. Delineation of segmental artery entry level into the spinal canal was graded as very good in 4 (16.7%), good in 11 (45.8%), sufficient in 6 (25.0%), and poor in 3 (12.5%) patients. Conclusions The use of 3-T MRA with an intravascular contrast agent and steady-state enables AKA localization including its segmental arteries with regard to the level of aortic origin and spinal canal entry in most patients.

Susceptibility-weighted MR imaging (SWI) is usually obtained without administration of intravenous gadolinium (Gd). However, it is occasionally necessary to perform SWI after Gd is injected. The effects of Gd on SWI have not been systematically examined. The aim of this prospective study was to investigate whether performing SWI after Gd would influence the diagnostic image quality, parenchymal signal and vascular enhancement. An additional aim is to suggest potential future applications for Gd-enhanced SWI.SWI was performed in 31 subjects before and after Gd administration. 17 cases were examined in a 1.5T scanner and the remaining 14 were scanned at 3T. The pre- and post-Gd images were analysed for signal changes in the cerebral grey matter (GM), white matter (WM) as well as for enhancement in the superficial and deep venous system. The visibility of the veins was graded on subtraction maps.The Gd-enhanced images showed no image quality degradation and no significant signal intensity change in the GM and WM as compared to the pre-Gd images (p0.05). After Gd-administration significant enhancement of the venous sinuses was noticed (p0.005), while the deep and cortical veins were poorly enhanced as confirmed by the calculated subtraction maps. The results showed no significant difference at variable MRI field strengths.It is possible to perform SWI after Gd injection without information loss or signal change in the parenchyma. The most significant difference is the enhancement of the cerebral venous sinuses. Potential future applications are discussed.

Navigation through a previously deployed and deformed stent is a difficult interventional task. Inadvertent navigation through the struts of a stent can potentially lead to incomplete secondary stent extension and vessel occlusion. Better visualisation of the pathway through the stent can reduce the risks of the procedural complications and reduce the reluctance of the interventionalist to navigate through a previously deployed stent. We describe a technique of visualisation of the pathway navigated by a guidewire through a previously deployed deformed and fractured carotid stent by the use of DynaCT. Three-dimensional reconstruction of the stent/microwire allows excellent visualisation of the correct pathway of the microwire within the stent.

BACKGROUND AND PURPOSE: Mechanical thrombectomy in ischemic stroke is of increasing interest as it is a promising strategy for fast and efficient recanalization. Several thrombectomy devices have been introduced to the armentarium of mechanical thrombectomy. Currently, new devices are under development and are continuously added to the neurointerventional tool box. Each device advocated so far has a different design and mechanical properties in terms of thrombus-device interaction. Therefore, a systematic evaluation under standardized conditions in vivo of these new devices is needed. The purpose of this study was to evaluate the efficiency, thrombus-device interaction, and potential complications of the novel Phenox CRC for distal mechanical thrombectomy in vivo. MATERIALS AND METHODS: The device was evaluated in an established animal model in the swine. Recanalization rate, thromboembolic events, vasospasm, and complications were assessed. Radiopaque thrombi (2 cm length) were used for the visualization of thrombus-device interaction during retrieval. The Phenox CRC (4 mm diameter) was assessed in 15 vessel occlusions. For every occlusion a maximum of 3 retrieval attempts were performed. RESULTS: Complete recanalization (TICI 3/TIMI 3) was achieved in 86.7% of vessel occlusions. In 66.7% (10/15), the first retrieval attempt was successful, and in 20% (3/15), the second attempt led to complete recanalization of the parent artery. In 2 cases (13.3%) thrombus retrieval was not successful (TICI 0/TIMI 0). In 1 case (6.7%) a minor embolic event occurred in a small side branch. No distal thromboembolic event was observed during the study. Thrombus-device interaction illustrated the entrapment of the thrombus by the microfilaments and the proximal cage of the device. No significant thrombus compression was observed. No vessel perforation, dissection, or fracture of the device occurred. CONCLUSIONS: In this small animal study, the Phenox CRC was a safe and effective device for mechanical thrombectomy. The unique design with a combination of microfilaments and proximal cage reduces thrombus compression with a consequently high recanalization and low complication rate.

Purpose The latest-generation Amplatzer vascular plug (AVP), the AVP 4, is designed for embolization of smaller vessels without a sheath or guiding catheter. This study evaluated the AVP 4 in peripheral vascular embolization. Materials and Methods Embolization with the AVP 4 was attempted in 13 patients (11 men) for trauma ( n = 7) and other indications ( n = 6). Technical success rate, vascular bed, size of catheter, and number and size of AVP 4 devices were recorded. Results Embolization with the AVP 4 was successful in 10 of 13 patients (77%). In trauma patients ( n = 7), embolization of the splenic artery ( n = 4), lumbar artery ( n = 2), and superior gluteal artery ( n = 1) was performed. In other patients, preoperative embolization of the right portal vein ( n = 1), a gastric varix after transjugular intrahepatic portosystemic shunt creation ( n = 1), an aneurysm of the internal iliac artery ( n = 1), and inferior mesenteric artery (IMA) embolization before aneurysm repair ( n = 2) was performed. Sizes of the AVP 4 were 4 mm ( n = 6), 6 mm ( n = 5), and 8 mm ( n = 1). In all patients, 4- and 5-F catheters with a 0.038-inch minimum inner lumen were used. In one patient, IMA embolization was attempted via a femoral approach but was unsuccessful as a result of repeated catheter tip dislocation because of acute angle; coils were used instead. Conclusions Peripheral embolization with the AVP 4 was successful in the majority of patients. Future comparative study is necessary to evaluate this device's benefits over other embolization materials such as earlier-generation AVPs or microcoils.

Background and Purpose— Stent placement has been applied in small case series as a rescue therapy in combination with different thrombolytic agents, percutaneous balloon angioplasty (PTA), and mechanical thromboembolectomy (MT) in acute stroke treatment. These studies report a considerable mortality and a high rate of intracranial hemorrhages when balloon-mounted stents were used. This study was performed to evaluate feasibility, efficacy, and safety of intracranial artery recanalization for acute ischemic stroke using a self-expandable stent. Methods— All patients treated with an intracranial stent for acute cerebral artery occlusion were included. Treatment comprised intraarterial thrombolysis, thromboaspiration, MT, PTA, and stent placement. Recanalization result was assessed by follow-up angiography immediately after stent placement. Complications related to the procedure and outcome at 3 months were assessed. Results— Twelve patients (median NIHSS 14, mean age 63 years) were treated with intracranial stents for acute ischemic stroke. Occlusions were located in the posterior vertebrobasilar circulation (n=6) and in the anterior circulation (n=6). Stent placement was feasible in all procedures and resulted in partial or complete recanalization (TIMI 2/3) in 92%. No vessel perforations, subarachnoid, or symptomatic intracerebral hemorrhages occurred. One dissection was found after thromboaspiration and PTA. Three patients (25%) had a good outcome (mRS 0 to 2), 3 (25%) a moderate outcome (mRS 3), and 6 (50%) a poor outcome (mRS 4 to 6). Mortality was 33.3%. Conclusions— Intracranial placement of a self-expandable stent for acute ischemic stroke is feasible and seems to be safe to achieve sufficient recanalization.

A blood clot needs to have the right degree of mechanical, chemical and biological properties to stem the flow of blood and yet to be suitable for lytic enzymes or mechanical thrombectomy so as not to form a thrombotic event. The origin and understanding of these mechanical properties are still unknown. Clots are made of a threedimensional network of fibrin fibers stabilized through ligation with a transglutaminase, factor XIIIa. New methods to achieve information about the in-situ mechanical properties were established. We performed compressive strength experiments of aged human blood clots. After the set up of a new test environment, we were able to perform in-situ tensile strength measurements of aged animal and human blood clots. Stress strain curves of aged clots were measured and discussed. The viscoelastic properties of the clot material were quantitatively described. This work should finally give a better understanding of the behaviour of aged blood thrombus bulk material and induced mechanical stress.

To analyze the immediate and midterm angiographic and clinical results of stent placement in the endovascular treatment of intracranial cerebral aneurysms.Out of 330 cerebral aneurysms treated by endovascular approach in our neurovascular centre, stents have been used in 18 patients. Twelve aneurysms (66.7%) were acutely ruptured, four (22.2%) were unruptured, two (11.1%) were recanalized after initial coiling. In three patients (16.7%) stent placement was used for revascularization of acute vessel thrombosis during coiling. Angiographic follow-up was obtained in 13 (72.2%) patients (mean 1.8 years, range 0.4-6.6) and clinical follow-up in 13 (72.2%) patients (mean 2.0 years, range 0.2-6.6).Complete occlusion was achieved in eight (44.4%) patients, a neck-remnant remained in four (22.2%) and an incomplete occlusion in four (22.2%). In the two cases of previously treated aneurysms a neck-remnant remained after secondary stent-assisted coiling. In four cases thromboembolic events resulted in a transient procedure related morbidity. No permanent procedure related morbidity or mortality was observed. One case of an asymptomatic late in-stent stenosis occurred. On clinical followup modified Ranking Score was 0 in 3 patients (23.1%), 1 in 3 patients (23.1%) and 2-3 in 7 patients (53.9%). On angiographic follow-up recanalisation was observed in 5 (38.5% = 5/13) aneurysms.Even in acutely ruptured aneurysms, stent assisted coiling can be a relatively effective and safe treatment for cerebral aneurysms. One asymptomatic in-stent stenosis occurred indicating that the risk rate of restenosis seems to be lower compared to stent deployment in atherosclerotic lesions, where restenosis rates up to 30% are described.

✓ Intracerebral hemorrhage (ICH), for which no effective treatment strategy is currently available, constitutes one of the most devastating forms of stroke. As a result, developing therapeutic options for ICH is of great interest to the medical community. The 3 potential therapies that have the most promise are cell replacement therapy, enhancing endogenous repair mechanisms, and utilizing various neuroprotective drugs. Replacement of damaged cells and restoration of function can be accomplished by transplantation of cells derived from different sources, such as embryonic or somatic stem cells, umbilical cord blood, and genetically modified cell lines. Early experimental data showing the benefits of cell transplantation on functional recovery after ICH have been promising. Nevertheless, several studies have focused on another therapeutic avenue, investigating novel ways to activate and direct endogenous repair mechanisms in the central nervous system, through exposure to specific neuronal growth factors or by inactivating inhibitory molecules. Lastly, neuroprotective drugs may offer an additional tool for improving neuronal survival in the perihematomal area. However, a number of scientific issues must be addressed before these experimental techniques can be translated into clinical therapy. In this review, the authors outline the recent advances in the basic science of treatment strategies for ICH.

The treatment of complex cerebrovascular or skull base pathological conditions necessitates a microsurgical blood flow preservation or augmentative revascularization procedure as either an adjunctive safety measure or a definitive treatment. The brain is susceptible to ischemia, and procedure-related risks can be minimized by the reduction of occlusion time or the use of a nonocclusive technique. The authors therefore analyzed the feasibility of an automatic device (C-Port xA, Cardica) designed for constructing an end-to-side anastomosis with or without flow interruption for a middle cerebral artery (MCA) bypass in a human cadaveric model and in an in vivo craniotomy simulation model.Four Thiel-fixated human head specimens were prepared using 8 standard pterional craniotomies. The sylvian fissure was opened to access the anterior circulation and in particular the MCA. The length of the individual vessel segments was measured. The C-Port xA was tested on each of the 8 exposures. In addition the C-Port xA was deployed in an in vivo craniotomy simulator model in 10 New Zealand rabbits (a total of 20 anastomoses) by using the abdominal aorta jump graft model.Short-term patency was assessed by angiography and histological findings. In all 8 sylvian exposures, construction of an MCA anastomosis with the aid of the C-Port xA was feasible. All 20 jump graft anastomoses performed in the in vivo craniotomy simulator were found to be patent.The anatomical studies as well as the in vivo craniotomy simulation studies demonstrated that the dimensions of the automated end-to-side anastomosis device are suitable for an extracranial-intracranial high-flow bypass on the MCA. Further miniaturization and special adaptation of this device would allow bypass procedures to more proximal intracranial vessels.

Current models of intracerebral hematoma are difficult to use for neurotransplantation studies because of high mortality and important variations of morphology, size and location of blood deposits. We propose a modification of the autologous blood infusion technique in rats to reduce these limitations.The modification consisted in a mechanical microlesion preceding blood infusion. A canula was stereotactically introduced into the striatum of adult rats. Subsequently, a parenchyma lesion was created by a rotating microcatheter coaxially inserted through the canula, followed by slow infusion of 30 mul autologous blood during 5 minutes. Controls included canula insertion only and canula + microlesion. Hematoma volume/morphology were quantified and the animals behaviorally analysed using standardized tests.Surgical mortality was 0/54 rats. One animal died during follow-up. Hematoma volume was constant and significantly higher (15.20 +/- 0.60 mm;3) than control lesions (canula: 0.11 +/- 0.01 mm;3; canula + trauma: 0.51 +/- 0.01 mm;3). Hematoma edges were sharply delineated and the perihematomal region histologically preserved. Rats with hematoma showed initially a reduced spontaneous rotational behaviour. They also showed persisting deficits of forelimb placing ability.The advantages of this model include a systematic control of all steps of hematoma production, high reproducibility of volume, size, and location of blood deposits, preservation of perihematomal brain tissue, and quantifiable neurological deficits.