Background and purposeTandem anterior circulation lesions in the setting of acute ischemic stroke (AIS) are a complex endovascular situation that has not been specifically addressed in trials. We determined the predictors of successful reperfusion and good clinical outcome at 90 days after mechanical thrombectomy (MT) in patients with AIS with tandem lesions in a pooled collaborative study.MethodsThis was a retrospective analysis of consecutive patients presenting to 18 comprehensive stroke centers with AIS due to tandem lesion of the anterior circulation who underwent MT.ResultsA total of 395 patients were included. Successful reperfusion (modified thrombolysis in cerebral infarction score 2b–3) was achieved in 76.7%. At 90 days, 52.2% achieved a good outcome (modified Rankin Scale score 0–2), 13.8% suffered a parenchymal hematoma and 13.2% were dead. Lower National Institutes of Health Stroke Scale score [odds ratio (OR), 1.26; 95% confidence intervals (CI), 1.07–1.48, P = 0.004], Alberta Stroke Program Early CT Score ≥7 (OR, 2.00; 95% CI, 1.07–3.43, P = 0.011), intravenous thrombolysis (OR, 1.47; 95% CI, 1.01–2.12, P = 0.042) and stenting of the extracranial carotid lesion (OR, 1.63; 95% CI, 1.04–2;53, P = 0.030) were independently associated with successful reperfusion. Lower age (OR, 1.58; 95% CI, 1.26–1.97, P < 0.001), absence of hypercholesterolemia (OR, 1.77; 95% CI, 1.10–2.84, P = 0.018), lower National Institutes of Health Stroke Scale scores (OR, 2.04; 95% CI, 1.53–2.72, P < 0.001), Alberta Stroke Program Early CT Score ≥7 (OR, 2.75; 95% CI, 1.24–6.10, P = 0.013) and proximal middle cerebral artery occlusion (OR, 1.59; 95% CI, 1.03–2.44, P = 0.035) independently predicted a good 90‐day outcome.ConclusionsIntravenous thrombolysis and emergent stenting of the extracranial carotid lesion were predictors of a successful reperfusion after MT of patients with AIS with tandem lesion of the anterior circulation.

Multiple studies have shown a clinical benefit of thrombectomy in acute ischaemic stroke, but most of them excluded octogenarians. The purpose of this study was to compare the outcomes between octogenarians and younger patients after thrombectomy.

While today mechanical thrombectomy is an established treatment option for main branch occlusions in anterior circulation stroke, there is still an ongoing debate on the kind of anesthesia to be preferred. Introducing a simple method for head stabilization, we analyzed safety and duration of endovascular recanalization procedures under general anesthesia (GA) and conscious sedation (CS).

3D-Time-of-flight magnetic-resonance-angiography (TOF MRA) is an established method in vessel analysis. However, many artifacts that occur may lead to a false diagnosis. This retrospective study evaluates the coherence of MR artifacts to extensive pneumatized air cells surrounding the internal carotid artery (ICA) in the petrosus part of the temporal bone.

INTRODUCTION:Basilar artery occlusion (BAO) causes mortality up to 90%.METHODS:A total of 99 patients with BAO received either endovascular (endovascular mechanical recanalization and/or intra-arterial with optional intravenous thrombolysis [IVT] as bridging concept) or conservative medical treatment (IVT and/or medical oral therapy). Outcome parameters were measured in accordance with the thrombolysis in cerebral infarction (TICI), National Institutes of Health Stroke Scale (NIHSS), and modified Rankin Scale (mRS) scores.RESULTS:In all, 78% underwent endovascular and 22% conservative medical treatment. The NIHSS at admission was 20 in both the groups. Postprocedurally, 36% (95% confidence interval: 26%-48%) of the endovascular group and 9% (21%-64%) of the conservative group reached TICI 3 (P = .017). In all, 30% of the endovascular group and 9% of the conservative group were documented with TICI 2b (P = .057). At 90 days follow-up, 45% (31%-60%) of the endovascular-treated patientsand no patient (0%-25%) of the conservative-treated group reached mRS ≤2 (P = .012).CONCLUSION:Endovascular treatment of BAO provides a better chance to survive this severe condition with good clinical outcome.

Background: Endovascular mechanical recanalization (EMR) is the most effective therapeutic strategy regarding large artery occlusion in stroke. Advanced age has been identified as one of the strongest predictors of poor outcomes.

Introduction/PurposeSuccessful revascularization following endovascular therapies for acute stroke has been defined inconsistently across studies. Technical success has been noted by angiography, although methods have varied considerably. Local site readings rather than core labs have been used, employing different scales, divergent definitions, and unqualified thresholds to ascribe success. Most importantly, revascularization success is rarely complemented by correlation with symptomatic intracranial hemorrhage (SICH) or clinical outcomes. Recent introduction of stentriever devices and potentially improved revascularization rates draws greater attention to specific definitions of such revascularization metrics. The Trevo® System utilizing Stentriever Technology is a novel device for thrombus removal recently reported in TREVO (ThrombectomyREvascularization of largeVesselOcclusions in acute ischemic stroke) Study. We tested a broad array of revascularization success definitions in TREVO to illustrate these distinct measures.Materials and MethodsTREVO was a multicenter, prospective, single-arm trial evaluating mechanical thrombectomy with the Trevo System across seven European sites, enrolling subjects aged 18–85 with NIHSS of 8–30 and treatment within 8 h from symptom onset. TREVO primary endpoint was target vessel revascularization, defined as TICI≥2a, read by the independent angiography and imaging core lab. Central angiography measures of target lesion location and TICI were compared to local readings. A battery of core lab measures were also analyzed, including SICH and clinical outcome endpoints of mRS 0–2 at 90 days, independently adjudicated.ResultsTREVO enrolled 60 subjects (median age 65 years and median NIHSS 18). TICI was measured post-device and at procedure end (final). Post-device, site and core lab agreed exactly in 46.7% (45.0% at final), while the site reported better scores than core lab in 36.7% post-device (50.0% at final), and lower scores than core lab in 16.7% (3.3% at final). Greatest discrepancy resulted from cases with site readings of TICI 3 and corresponding core lab readings of TICI 2b. Overall, good agreement between site and core lab occurred with designation in location of target occlusion (90%), with core lab using a more distal reference in 5 and a more proximal reference in 1. Revascularization post-device (TICI≥2a) was 76.7% by site and 90.0% by core lab, with final success of 90.0% by site and 91.7% by core. Success defined by core TICI≥2b was 72% after device use and 78% final. The core lab also graded TIMI revascularization with success obtained in 74.1% post-device and 79.3% final. Final revascularization success without SICH defined by core lab was achieved in 83.3% (TICI≥2a) and 70% (TICI≥2b), with 72.4% for TIMI 2/3. Good clinical outcomes (day 90 mRS 0-2) occurred in 62.3% with core lab TICI≥2a final success and 60.0% with core lab TICI≥2b final success. Correlation between revascularization measures and clinical outcomes was good for all angiographic measures, yet strongest for final TIMI 2/3 (63.4%).ConclusionTREVO demonstrates the high rates of revascularization success with novel Stentriever technology, substantiated by a broad range of metrics. Discrepancies in the definition of revascularization success illustrated by these measures should prompt similar analyses of recent and ongoing multicenter studies.Competing interestsD Liebeskind: NIH-NINDS. Concentric Medical, CoAxia. O Jansen: Concentric Medical. G Walker: Concentric Medical. J Macho: None. M Killer: None. N Wahlgren: Concentric Medical.

BACKGROUND AND PURPOSE: For embolized cerebral aneurysms, the initial occlusion rate is the most powerful parameter to predict aneurysm rerupture and recanalization. However, the occlusion rate is only estimated subjectively in clinical routine. To minimize subjective bias, computer occlusion-rating (COR) was successfully validated for 2D images. To minimize the remaining inaccuracy of 2D-COR, COR was applied to 1.5T 3D MR imaging. MATERIALS AND METHODS: Twelve experimental rabbit aneurysms were subjected to stent-assisted coil embolization followed by 2D DSA and 3D MR imaging. Subjective occlusion-rate (SOR) was estimated. Linear parameters (aneurysm length, neck width, parent vessel diameter) were measured on 2D DSA and 3D MR imaging. The occlusion rate was measured by contrast medium−based identification of the nonoccluded 2D area/3D volume in relation to the total aneurysm 2D area/3D volume. 2D and 3D parameters were statistically compared. RESULTS: There were no limiting metallic artifacts by using 3D MR imaging. Linear parameters (millimeters) were nearly identical on 2D DSA and 3D MR imaging (aneurysm length: 7.5 ± 2.6 versus 7.4 ± 2.5, P = .2334; neck width: 3.8 ± 1.0 versus 3.7 ± 1.1, P = .6377; parent vessel diameter: 2.7 ± 0.6 versus 2.7 ± 0.5, P = .8438), proving the high accuracy of 3D MR imaging. COR measured on 3D MR imaging was considerably lower (61.8% ± 26.6%) compared with the following: 1) 2D-COR (65.6% ± 27.1%, P = .0537) and 2) 2D-SOR estimations (69.2% ± 27.4%, P = .002). These findings demonstrate unacceptable bias in the current clinical standard SOR estimations. CONCLUSIONS: 3D-COR of embolized aneurysms is easily feasible. Its accuracy is superior to that of the clinical standard 2D-SOR. The difference between 3D-COR and 2D-COR approached statistical significance. 3D-COR may add objectivity to the ability to stratify the risk of rerupture in embolized cerebral aneurysms.

BACKGROUND AND PURPOSE:Beam-hardening artifacts in CTA can be greatly reduced by using metal-free coils for aneurysm embolization. We compared the embolic masses and remnants of experimental rabbit aneurysms coiled with hydrogel filaments by using DSA, CTA and histology.MATERIALS AND METHODS:Embolization of 12 rabbit bifurcation aneurysms was performed with detachable hydrogel filaments. Six aneurysms were embolized as completely as possible, and 6 aneurysms were embolized incompletely to intentionally leave remnants. Three aneurysms in each group underwent follow-up at 4 and 13 weeks. DSA, MRA, and CTA were performed immediately before sacrifice. The harvested aneurysms were evaluated histologically. For each imaging technique, the areas of the embolic mass and remnant were determined by using image analysis. Results were compared by using paired t tests.RESULTS:CTAs were suitable for quantification of the embolus and remnant areas because only small streaking artifacts were evident. The areas of the embolus were larger on CTA compared with DSA and histologic sections. The areas of the remnant were larger on CTA and MRA compared with DSA and histologic sections. Like DSA and MRA, CTA was suitable for determining whether aneurysm retreatment was necessary, provided that loops of hydrogel filaments were not present in the parent artery.CONCLUSIONS:We demonstrated that CTA is a technique with potential for surveillance of aneurysms treated with hydrogel filaments. Additional work is required to determine the accuracy of the technique compared with currently accepted imaging modalities of DSA and MRA.

To propose a new computed tomography (CT)-based classification system for non-aneurysmal subarachnoid haemorrhage (SAH), which predicts patients' discharge clinical outcome and helps to prioritize appropriate patient management. A 5-year, retrospective, two-centre study was carried out involving 1486 patients presenting with SAH. One hundred and ninety patients with nonaneurysmal SAH were included in the study. Initial cranial CT findings at admission were correlated with the patients' discharge outcomes measured using the Modified Rankin Scale (MRS). A CT-based classification system (type 1 e 4) was devised based on the topography of the initial haemorrhage pattern. Seventy-five percent of the patients had type 1 haemorrhage and all these patients had a good clinical outcome with a discharge MRS of 1. Eight percent of the patients presented with type 2 haemorrhage, 62% of which were discharged with MRS of 1 and 12% of patients had MRS 3 or 4. Type 3 haemorrhage was found in 10%, of which 16% had good clinical outcome, but 53% had moderate to severe disability (MRS 3 and 4) and 5% were discharged with severe disability (MRS 5). Six percent of patients presented with type 4 haemorrhage of which 42% of the patients had moderate to severe disability (MRS 3 and 4), 42% had severe disability and one-sixth of the patients died. Highly significant differences were found between type 1 (1a and 1b) and type 2 (p(1/4) 0.003); type 2 and type 3 (p (1/4) 0.002); type 3 and type 4 (p (1/4) 0.001). Haemorrhages of the type 1 category are usually benign and do not warrant an extensive battery of clinical and radiological investigations. Type 2 haemorrhages have a varying prognosis and need to be investigated and managed along similar lines as that of an aneurysmal haemorrhage with emphasis towards radiological investigation. Type 3 and type 4 haemorrhages need to be extensively investigated to find an underlying cause.

We report our initial experience with a Solitaire AB neurovascular remodeling stent device in performing cerebral embolectomy in seven patients presenting to our institution with acute stroke who were resistant to iv thrombolytic drug treatment. The main inclusion criteria were: National Institutes of Health Stroke Scale (NIHSS) score ≥10; treatment performed within 8 h from the onset of symptoms and no large hypodensity on CT; and occlusion of a major cerebral artery on the CT angiogram. An admission and a post-interventional NIHSS score were calculated for all patients by two different neurologists. Efficacy was assessed radiologically by post-treatment thrombolysis in myocardial infarction (TIMI) scores and clinically by a 30-day Modified Rankin Scale (MRS) score. The mean duration of neurointerventional treatment was 84 min. All interventions were successful, with TIMI scores of 2 or 3 achieved in 100% of patients. There was one procedural complication in our series owing to a self-detached stent and one patient had a small asymptomatic basal ganglia haemorrhage. There was improvement of more than 4 points on the NIHSS score in 5 (72%) of the patients following treatment, of whom 4 (57%) had a 30-day MRS score of ≤2. The use of a Solitaire stent in acute stroke was safe, time-efficient and encouraging; however, a larger sample size will be required to further evaluate the use of this device, which could benefit a significant number of stroke patients.

BACKGROUND:The aim of this study was to compare the performance of a new filling coil, the HydroFill device, to historical results of HydroSoft and bare platinum coil devices in experimental rabbit aneurysms. METHODS:Experimental aneurysms were constructed in rabbits and embolized with HydroFill (n=32), HydroSoft (n=48), or bare platinum coil (n=47) devices. Angiographic occlusion was evaluated post-treatment and at 1 month (n=55), 3 month (n=20), 6 month (n=35), and 12 month (n=12) follow-ups according to the Raymond scale. The aneurysms were analyzed histologically for neointima formation, thrombus organization, and inflammation. Continuous and discrete results were compared using ANOVA/t-test and chi (2) tests, respectively. RESULTS:Volumetric occlusion of the aneurysm sac was increased in the HydroFill group compared to the HydroSoft and platinum coil groups. Protrusions into the parent artery were common in all treatment groups due to the treatment of wide-necked aneurysms without the use of balloons or stents. Although angiographic occlusion post-treatment scores were reduced in the HydroFill group compared to the HydroSoft and platinum coil groups, stable/progressive occlusion was increased in the HydroFill group compared to the platinum coil group. Histologically, neointima formation and thrombus organization scores were increased in the HydroFill and HydroSoft groups compared to the platinum coil group at 3 months. Although there were some differences in the scoring, inflammation was generally minimal to mild in all three groups. CONCLUSION:The HydroFill device, with its high levels of volumetric filling, increased stable/progressive occlusion at follow-up, increased neointima formation, and increased thrombus organization, shows promise for clinical use.

Objective: Complications with increased mass effect on surrounding structures hive as yet only been noted after coiling of large, giant, and thrombosed aneurysms. We describe a case of optic chiasm compression after incomplete coil embolization of a small ICA aneurysm and discuss the potential mechanisms causing this phenomenon.Case Report: A 57-year-old male presented with an incidental, 7-mm diameter, C2 segment, ICA aneurysm. Endovascular intervention with platinum coils resulted in 80% obliteration. Approximately three weeks later the patient developed visual changes which progressed over 10 days to a homonymous hemianopsia with a central scotoma. A pterional craniotomy was performed to decompress and to definitively clip the aneurysm. Histological evaluation of the aneurysm showed sinusoidal vessels, filled with proliferated endothelial cells and being encapsulated by fibrous tissue, Suspicious for exposure to systemic blood pressure.Conclusion: Even small aneurysms undergoing incomplete coil embolization may affect surrounding, eloquent neural structures due to unexpected tissue formation in the aneurysm.

BACKGROUND AND PURPOSE: The embolization of aneurysms with hydrogel filaments allow postprocedural CT and MR imaging studies without artifacts. We compared the performance of 3 hydrogel filament formulations in rabbit experimental aneurysms by using angiography and histologic samples.MATERIALS AND METHODS: Embolization of 35 rabbit elastase or bifurcation aneurysms was performed with 3 different formulations of detachable hydrogel filaments, including 1) polyethylene glycol opacified with aromatic iodine (PEG-1; n = 12), 2) polyethylene glycol opacified with barium sulfate (PEG-B; n = 12), or 3) polypropylene glycol opacified with barium sulfate (PPG-B; n = 11). Follow-up angiography was performed before the rabbits were killed at 2 (n = 7), 6 In = 9), 10 (n = 8), or 26 (n = 11) weeks. Angiographic occlusion was scored according to the Raymond scale, and interval changes were assessed. The harvested aneurysms were evaluated on histologic examination. From the sections, we determined the percentage of the sac excluded from the vasculature and occupied by embolic devices by using image analysis. We compared results using the analysis of variance/t test or chi(2) test.RESULTS: The mean number of devices used to treat aneurysms in the PPG-B group was significantly greater than that used for the other 2 groups, though aneurysm volumes were similar among groups. Compared with immediate posttreatment occlusion scores, mean angiographic occlusion at follow-up was increased for all 3 hydrogel filament groups. On histologic examination, thrombus organization, neointima formation, and inflammation were similar to that observed in rabbit experimental aneurysms with other embolic devices containing platinum coils.CONCLUSIONS: The embolization of experimental aneurysms with hydrogel filaments resulted in durable angiographic and histologic occlusion from 2 to 26 weeks. With improvements, hydrogel filaments free from metallic coils show promise for endovascular use.

Introduction: Recanalisation of aneurysms after interventional therapy is still an unsolved problem. The aim of this study is to demonstrate the angiographic and histological evidence of healing after endovascular embolisation of experimental aneurysms.Methods: We evaluated the healing reaction in experimental aneurysms treated with HydroCoils and platinum coils. After microsurgical construction of aneurysms in 24 rabbits, embolisation was performed. Four animals were sacrificed immediately after embolisation and 5 after I month, 3 months and 6 months, respectively, the remaining served as control group. Serial plastic-embedded ground sections of the parent arteries-aneurysm complexes were evaluated by light microscopy.Results: Thrombus organisation in the aneurysms resulted in fibrovascular tissue formation between bare platinum and HydroCoils from the walls of the aneurysms towards the centre of the sac over time. In the clefts between HydroCoils only thin strands of granulation tissue were observed. From one month on, there was a neointimal layer covering the coil mass at the aneurysm orifice.Conclusion: Progressive occlusion by the expanding hydrogel polymers on the coils seemed to result in a durable healing reaction in the aneurismal sac in a short-term follow-up period.

Occurrence and histomorphology of cartilage and bone neoformations was retrospectively evaluated in rabbit experimental aneurysms after endovascular coil embolization. During product development, 115 carotid bifurcation aneurysms were treated with hydrogel-containing devices (HydroCoil or target, n=77; HydroSoft or target, n=28; prototype Hydrogel-only, n=10; MicroVentionTerumo, Aliso Viejo, CA). Additional 29 aneurysms were treated with standard (n=22) or with degradable polymer-covered (n=7) platinum coils. After 4 to 52 weeks, the retrieved aneurysms were methylmethacrylate embedded, and ground sections were surface-stained with Rapid Bone Stain and Giemsa solution. Cartilage and/or bone tissue was assessed by light microscopy; respective tissue areas in the aneurysms were determined by computerized histomorphometry. Cartilage neoformation was observed from 26 to 52 weeks. Single chondrocytes to hyaline or fibrous cartilage areas, occupying up to 29% of the aneurysm cavity, were found in 6 aneurysms, treated with HydroCoil (n=4), Hydrogel-only (n=1), and resorbable polymer (n=1) devices. Chondral ossification associated cartilage neoformation in 2 of these 4 HydroCoil-treated aneurysms. Membranous woven and lamellar bone ossicles were observed from 13 to 52 weeks in 7 aneurysms, treated with HydroCoil (n=3) and platinum coil (n=4) devices. Altogether, cartilage and/or bone neoformation was observed in 13 (9%) of 144 rabbit bifurcation aneurysms treated with various embolic devices. Incidence was low until 26 weeks, but increased at 52 weeks in both, HydroCoil and standard platinum coil treated aneurysms. As the neoformations were predominantly located in proximity to the aneurysm neck, they could be related to the long-term mechanobiology of cell differentiation during fibrovascular healing of blood flow-exposed embolized aneurysms.

Functional imaging of brain tumors assists biopsy localization, therapy monitoring, and differentiating tumor recurrence from radiation necrosis. Tumor vascularization is a strong prognostic predictor in solid tumors and also a key factor of tracer uptake. However, the relationship of brain tumor vascularization and functional imaging has not yet been investigated sufficiently so far. In the present study, we correlated histologically assessed microvessel density as an objective parameter for brain tumor vascularization with imaging data. Four male patients were studied. After 99mTc-MIBI scintigraphy, all patients had a MRI within 2 weeks. Histology showed microcystic astrocytoma, glioblastoma (n = 2), and anaplastic oligodendroglioma, respectively. Microvessel density was lowest in the microcystic astrocytoma, medium in the glioblastomas, and highest in the anaplastic oligodendroglioma. Scintigraphy visualized only the glioblastomas, but not the microcystic astrocytoma or oligodendroglioma. Our data showed no correlation between tumor microvessel density and 99mTc-MIBI scintigraphy. Thus, we conclude that scintigraphic visualization of brain tumors is not strictly dependent on tumor vascularization.