Can micro-guidewire advancement forces predict clot consistency and location to assist the first-line technique for mechanical thrombectomy?

BACKGROUND: The identification of specific clot characteristics before mechanical thrombectomy (MTB) might allow the selection of the most effective first-line technique, thus potentially improving the procedural outcome. We aimed to evaluate if the microwire push forces could extrapolate information on clot consistency and extension before MTB, based on clot mechanical properties. METHODS: We measured in vitro the forces exerted on the proximal extremity of the guidewire during the advancement and retrieval of the guidewire through clot analogs of different compositions. In addition, we analyzed the forces exerted on the guidewire to extrapolate information about the location of the proximal and distal extremities of the clot analogs. RESULTS: The maximum forces recorded during the whole penetration phase were significantly different for hard and soft clots (median values, 55.6 mN vs 15.4 mN, respectively; P<0.0001). The maximum slope of the force curves recorded during the advancement of the guidewire for the first 3 s of penetration also significantly differentiated soft from hard clot analogs (7.6 mN/s vs 23.9 mN/s, respectively; P<0.0001). In addition, the qualitative analysis of the shape of the force curves obtained during the advancement and retrieval of the guidewire showed a good potential for the identification of the proximal and distal edges of the clot analogs. CONCLUSION: Our results demonstrated that it was possible to differentiate between soft and hard clot analogs. Furthermore, force measurements could give important information about the location of the clot extremities. Such an approach might support the selection of the first-line MTB technique, with the potential to improve the outcome.

Inflammation biomarkers in the intracranial blood are associated with outcome in patients with ischemic stroke.

BACKGROUND: Performing endovascular treatment (EVT) in patients with acute ischemic stroke (AIS) allows a port of entry for intracranial biological sampling. OBJECTIVE: To test the hypothesis that specific immune players are molecular contributors to disease, outcome biomarkers, and potential targets for modifying AIS. METHODS: We examined 75 subjects presenting with large vessel occlusion of the anterior circulation and undergoing EVT. Intracranial blood samples were obtained by microcatheter aspiration, as positioned for stent deployment. Peripheral blood samples were collected from the femoral artery. Plasma samples were quality controlled by electrophoresis and analyzed using a Mesoscale multiplex for targeted inflammatory and vascular factors. RESULTS: We measured 37 protein biomarkers in our sample cohort. Through multivariate analysis, adjusted for age, intravenous thrombolysis, pretreatment National Institutes of Health Stroke Scale and Alberta Stroke Program Early CT scores, we found that post-clot blood levels of interleukin-6 (IL-6) were significantly correlated (adjusted P value <0.05) with disability assessed by the modified Rankin Scale (mRS) score at 90 days, with medium effect size. Chemokine (C-C) ligand 17 CCL17/TARC levels were inversely correlated with the mRS score. Examination of peripheral blood showed that these correlations did not reach statistical significance after correction. Intracranial biomarker IL-6 level was specifically associated with a lower likelihood of favorable outcome, defined as a mRS score of 0-2. CONCLUSIONS: Our findings show a signature of blood inflammatory factors at the cerebrovascular occlusion site. The correlations between these acute-stage biomarkers and mRS score outcome support an avenue for add-on and localized immune modulatory strategies in AIS.

Interaction between intravenous thrombolysis and clinical outcome between slow and fast progressors undergoing mechanical thrombectomy: a post-hoc analysis of the SWIFT-DIRECT trial.

BACKGROUND: In proximal occlusions, the effect of reperfusion therapies may differ between slow or fast progressors. We investigated the effect of intravenous thrombolysis (IVT) (with alteplase) plus mechanical thrombectomy (MT) versus thrombectomy alone among slow versus fast stroke progressors. METHODS: The SWIFT-DIRECT trial data were analyzed: 408 patients randomized to IVT+MT or MT alone. Infarct growth speed was defined by the number of points of decay in the initial Alberta Stroke Program Early CT Score (ASPECTS) divided by the onset-to-imaging time. The primary endpoint was 3-month functional independence (modified Rankin scale 0-2). In the primary analysis, the study population was dichotomized into slow and fast progressors using median infarct growth velocity. Secondary analysis was also conducted using quartiles of ASPECTS decay. RESULTS: We included 376 patients: 191 IVT+MT, 185 MT alone; median age 73 years (IQR 65-81); median initial National Institutes of Health Stroke Scale (NIHSS) 17 (IQR 13-20). The median infarct growth velocity was 1.2 points/hour. Overall, we did not observe a significant interaction between the infarct growth speed and the allocation to either randomization group on the odds of favourable outcome (P=0.68). In the IVT+MT group, odds of any intracranial hemorrhage (ICH) were significantly lower in slow progressors (22.8% vs 36.4%; OR 0.52, 95% CI 0.27 to 0.98) and higher among fast progressors (49.4% vs 26.8%; OR 2.62, 95% CI 1.42 to 4.82) (P value for interaction <0.001). Similar results were observed in secondary analyses. CONCLUSION: In this SWIFT-DIRECT subanalysis, we did not find evidence for a significant interaction of the velocity of infarct growth on the odds of favourable outcome according to treatment by MT alone or combined IVT+MT. However, prior IVT was associated with significantly reduced occurrence of any ICH among slow progressors whereas this was increased in fast progressors.

Efficacy and safety of low dose intravenous cangrelor in a consecutive cohort of patients undergoing neuroendovascular procedures.

BACKGROUND: Cangrelor is an intravenous P2Y12 inhibitor with rapid onset and fast offset of antiplatelet action. Dose adjusted cangrelor based on platelet function testing is suggested to be advantageous for use during neuroendovascular procedures. In this study, we aimed to assess the efficacy and safety of this strategy. METHODS: This retrospective study included consecutive patients who received low dose intravenous cangrelor (5 µg/kg; infusion 1 µg/kg/min) for ruptured (RIA) and unruptured (UIA) intracranial aneurysms, and acute ischemic stroke (AIS). Indications were acute stenting or intraluminal thrombus. Outcomes were assessed at 24 hours by brain CT and CT angiography. The primary efficacy outcome was the rate of stent occlusion or persistent intraluminal thrombus. The primary safety outcome was the rate of major hemorrhages. RESULTS: 101 patients (56 men; median age (IQR) 59 (51-70) years) received low dose cangrelor for acute stenting (79/101 (78%)) and intraprocedural thrombus (22/101 (22%)). Overall, 5 (4.9%) patients experienced stent occlusion within 24 hours (RIA 3/28; AIS 2/52). There were no cases of failure among UIA patients. Stent mis-opening (fish mouthing or stenosis >50%) was significantly associated with stent occlusion (P<0.001). The overall rate of major hemorrhage was 2% (2/101), which occurred in AIS patients. Platelet reactivity unit (PRU) values were lower in those presenting with major hemorrhage (PRU 4 (SD 1.4) vs PRU 60 (SD 63); P=0.043). Mortality rate after cangrelor related hemorrhage was 1%. CONCLUSIONS: Low dose cangrelor appears to be effective in preventing stent thrombosis and arterial patency with a low hemorrhagic risk.

Intracranial Aneurysm Classifier Using Phenotypic Factors: An International Pooled Analysis.

Intracranial aneurysms (IAs) are usually asymptomatic with a low risk of rupture, but consequences of aneurysmal subarachnoid hemorrhage (aSAH) are severe. Identifying IAs at risk of rupture has important clinical and socio-economic consequences. The goal of this study was to assess the effect of patient and IA characteristics on the likelihood of IA being diagnosed incidentally versus ruptured. Patients were recruited at 21 international centers. Seven phenotypic patient characteristics and three IA characteristics were recorded. The analyzed cohort included 7992 patients. Multivariate analysis demonstrated that: (1) IA location is the strongest factor associated with IA rupture status at diagnosis; (2) Risk factor awareness (hypertension, smoking) increases the likelihood of being diagnosed with unruptured IA; (3) Patients with ruptured IAs in high-risk locations tend to be older, and their IAs are smaller; (4) Smokers with ruptured IAs tend to be younger, and their IAs are larger; (5) Female patients with ruptured IAs tend to be older, and their IAs are smaller; (6) IA size and age at rupture correlate. The assessment of associations regarding patient and IA characteristics with IA rupture allows us to refine IA disease models and provide data to develop risk instruments for clinicians to support personalized decision-making.

Experimental evaluation of direct thromboaspiration efficacy according to the angle of interaction between the aspiration catheter and the clot.

BACKGROUND: Successful direct thromboaspiration (DTA) is related to several factors such as clot consistency, size, and location. It has also been demonstrated recently that the angle of interaction (AOI) formed by the aspiration catheter and the clot is related to DTA efficacy. The aims of this study were three-fold: (a) to confirm the clinical finding that the AOI formed by the aspiration catheter and the clot influence DTA efficacy; (b) to evaluate to what extent this influence varies according to differences in clot consistency and size; and (c) to validate stent retriever thrombectomy as an effective rescue treatment after DTA failure in the presence of an unfavorable AOI. METHODS: A rigid vascular phantom designed to reproduce a middle cerebral artery trifurcation anatomy with three M2 segments forming different angles with M1 and thrombus analog of different consistencies and sizes was used. RESULTS: DTA was highly effective for AOIs >125.5°, irrespective of thrombus analog features. However, its efficacy decreased for acute AOIs. Rescue stent retriever thrombectomy was effective in 92.6% of cases of DTA failure. CONCLUSIONS: This in vitro study confirmed that the AOI formed by the aspiration catheter and the thrombus analog influenced DTA efficacy, with an AOI >125.5° related to an effective DTA. Stent retriever thrombectomy was an effective rescue treatment after DTA failure, even in the presence of an unfavorable AOI.

Thoracic aggressive vertebral hemangiomas: multidisciplinary management in a hybrid room.

PURPOSE: Vertebral hemangiomas (VH) account for 2-3% of all spinal tumors. The majority is incidentally found on radiographic studies: 1% present with pain and/or neurologic deficits. We report our experience with the multidisciplinary management of aggressive symptomatic thoracic VH by concomitant intraoperative sclerotization with sodium tetradecyl sulfate (STS), vertebroplasty, posterior decompression (with/without fusion) and surgical resection in a hybrid operating room (HR) equipped with a rotational scanner and a radiolucent operating table. METHODS: Patients admitted with aggressive spinal VH between 2007 and 2018 were included. Data regarding demographics, presenting symptoms, location of the lesion, preoperative embolization, length of the surgery, estimated blood loss (EBL) as well as follow-up (FU) were retrieved. RESULTS: Five patients were included (three females, mean age 65 years; range 59-75). Three patients presented with a myelopathy and two mechanical thoracic pain. All patients underwent a single-stage percutaneous sclerotization and vertebroplasty followed by a surgical decompression associated with epidural intralesional injection of STS and subtotal resection of the epidural lesion. Two patients had preoperative embolization. Mean procedural duration was 338 min (range 210-480 min). Four patients had marginal EBL, one patient had 500 ml EBL. Patients had no evidence of lesion recurrence or progression at the end of the follow-up. CONCLUSIONS: The single-stage multimodal management of aggressive symptomatic VH is safe and effective. It allows for a direct intraoperative sclerotherapy combined with maximal tumor resection, resulting in reduced blood loss. The use of STS as a direct intraoperative sclerotizing agent is safe and reliable.

Direct thromboaspiration efficacy for mechanical thrombectomy is related to the angle of interaction between the aspiration catheter and the clot.

BACKGROUND: Direct thromboaspiration has been reported as an effective mechanical treatment for acute ischemic stroke. We aimed to determine whether the angle of interaction between the aspiration catheter and the clot affects the success of clot removal in ischemic stroke patients with large vessel occlusion in the anterior and posterior circulation. METHODS: All patients treated at our institution by direct thromboaspiration as a firstline technique between January 2016 and December 2017 were enrolled in the study. We retrospectively reviewed baseline and procedural characteristics, the angle of interaction formed between the aspiration catheter and the clot, the modified Thrombolysis in Cerebral Infarction score, and the 3 month modified Rankin Scale score. RESULTS: 85 patients underwent direct thromboaspiration as the firstline treatment during the study period. 100 direct thromboaspiration passes were performed. An angle of interaction of ≥125.5° significantly influenced the success of clot removal (P<0.001) with good sensitivity and specificity, in particular for occlusion of the middle cerebral and basilar artery. The combination of aspiration with a stent retriever based thrombectomy was a valid rescue treatment in cases of standalone direct thromboaspiration failure. CONCLUSIONS: In our series, an angle of interaction between the aspiration catheter and the clot of ≥125.5° was significantly associated with successful clot removal. The prediction of the angle of interaction on pretreatment imaging may help operators to select the most adequate mechanical thrombectomy technique on a case by case basis.

Posterior Fossa Arteriovenous Malformations: Experience with 14 Patients and a Systematic Review of the Literature.

BACKGROUND: The optimal management of posterior fossa arteriovenous malformations (pfAVMs) is a matter of debate. To advance this discussion, we present our clinical series and the results of a systematic literature review according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. METHODS: Fourteen consecutive patients with pfAVMs were admitted between 2007 and 2018. Preoperative status, radiologic parameters, and outcome were assessed. A systematic literature review was performed according to the PRISMA-P guidelines. RESULTS: Ten patients presented with rupture (71%), of whom three had associated aneurysms (AAs). The treatments were microsurgery (n = 4), endovascular (n = 3), radiosurgery (n = 2), a combination of two or three treatment modalities (n = 3), or conservative (n = 2). At discharge, all four patients (100%) with unruptured pfAVMs had a good outcome (modified Rankin Scale [mRS]: 0-2). In contrast, in ruptured pfAVM cases, mRS was 0 to 2 in four patients (40%), mRS 3 to 4 in two (20%), mRS 5 in three (30%), and one patient (10%) died within 30 days after gamma knife treatment due to pancreatitis secondary to chronic alcohol abuse. At discharge, four patients (29%) had persistent preinterventional cranial nerve and/or focal neurologic deficits. The literature review identified 63 articles with 1,753 pfAVM patients. Overall, 66% of pfAVMs presented with rupture, and AAs were found in 20% of the cases, which is higher than in supratentorial AVMs (stAVMs). CONCLUSIONS: Because pfAVMs are associated with higher rates of hemorrhagic presentation, higher rates of morbidity and mortality when ruptured, and have a higher incidence of AAs compared with stAVMs, early curative treatment is recommended as soon as the diagnosis is established, regardless of rupture status.

Neurovascular stent artifacts in 3D-TOF and 3D-PCMRI: Influence of stent design on flow measurement.

PURPOSE: The morphological and hemodynamic evaluations of neurovascular diseases treated with stents would benefit from noninvasive imaging techniques such as 3D time-of-flight MRI (3D-TOF) and 3D phase contrast MRI (3D-PCMRI). For this purpose, a comprehensive evaluation of the stent artifacts and their impact on the flow measurement is critical. METHODS: The artifacts of a representative sample of neurovascular stents were evaluated in vitro with 3D-TOF and 3D-PCMRI sequences. The dependency of the artifacts with respect to the orientation was analyzed for each stent design as well as the impact on the flow measurement accuracy. Furthermore, the 3D-PCMRI data of four patients carrying intracranial aneurysms treated with flow diverter stents were analyzed as illustrative examples. RESULTS: The stent artifacts were mainly confined to the stent lumen therefore indicating the leading role of shielding effect. The influence of the stent design and its orientation with respect to the transmitting MR coils were highlighted. The artifacts impacted the 3D-PCMRI velocities mainly in the low magnitude domains, which were discarded from the analysis ensuring reliable near-stent velocities. The feasibility of in-stent flow measurements was confirmed in vivo on two patients who showed strong correlation between flow and geometric features. In two other patients, the consistency of out-of-stent velocities was verified qualitatively through intra-aneurysmal streamlines except when susceptibility artifacts occurred. CONCLUSION: The present results motivate the conception of low inductance or nonconductive stent design. Furthermore, the feasibility of near-stent 3D-PCMRI measurements opens the door to clinical applications like the post-treatment follow-up of stenoses or intracranial aneurysms.

Solitaire FR thrombectomy system: immediate results in 56 consecutive acute ischemic stroke patients.

BACKGROUND AND PURPOSE: Prompt recanalization of cerebral arteries in patients diagnosed with acute ischemic stroke is known to be associated with a better clinical outcome. The aim of this study was to present our initial experience regarding the efficacy and safety of the Solitaire FR as a revascularization device. METHODS: 56 consecutive patients presenting with acute ischemic stroke underwent intra-arterial therapy using the Solitaire FR revascularization device. Immediate angiographic results and early clinical outcomes are presented. RESULTS: Solitaire FR was successful in achieving recanalization in 50 out of 56 patients (89%) with a final Thrombolysis in Cerebral Infarction score ≥2b. Five out of 56 patients had procedure related complications: two asymptomatic subarachnoid hemorrhages, two thromboembolic events and one symptomatic intracranial hemorrhage (PH2). Thirty patients (53.5%) demonstrated at discharge a National Institutes of Health Stroke Scale Score of ≤1 or an improvement of at least 10 points from baseline, and 26 patients (46%) had a modified Rankin Score ≤2. CONCLUSIONS: Solitaire FR is successful in achieving a high rate of arterial recanalization with a low complication rate. The Solitaire FR is a promising thrombectomy tool with a high degree of effectiveness, safety and ease of use.

Outcome of transarterial treatment of dural arteriovenous fistulas with direct or indirect cortical venous drainage.

BACKGROUND AND PURPOSE: Transarterial Onyx embolization is an effective treatment for patients with intracranial dural arteriovenous fistula (DAVF). A study was performed to determine whether the clinical and radiological outcomes after transarterial Onyx treatment were affected by the type of cortical venous drainage (direct vs indirect) of high-grade DAVF. MATERIALS AND METHODS: Between May 2006 and December 2014, demographic data, clinical presentation, angiographic characteristics, and treatment-related outcomes were collected for 54 patients divided into two groups (intracranial DAVF with direct and indirect cortical venous drainage). Continuous variables were compared with the two-tailed t test and categorical variables with the χ2 test. Statistical significance was set at P<0.05. RESULTS: Fifty-two patients (71% with direct and 29% with indirect cortical venous drainage) underwent Onyx embolization. Immediate complete occlusion after treatment was observed in about 55% of patients without between-group difference. During the long-term follow-up, complete angiographic occlusion was achieved in 83% of patients. Specifically, 15 additional patients (40%) in the direct cortical venous drainage group progressed to complete occlusion, but only one (6%) in the indirect cortical venous drainage group. Overall, the rate of complete occlusion was higher in patients with DAVF with direct cortical venous drainage (92%) than in those with DAVF with indirect cortical venous drainage (62.5%) (P=0.01). The rate of permanent treatment-related complications was 4%, mostly related to ischemic events. Overall, 80.5% of patients had a good neurological outcome (modified Rankin Scale score 0-2). CONCLUSIONS: Transarterial Onyx embolization of intracranial high-grade DAVF is safe and effective, particularly for lesions with direct cortical venous drainage.

Safety and effectiveness of the Low Profile Visualized Intraluminal Support (LVIS and LVIS Jr) devices in the endovascular treatment of intracranial aneurysms: results of the TRAIL multicenter observational study.

BACKGROUND AND PURPOSE: To evaluate the safety and effectiveness of the low-profile braided intracranial stents called the Low Profile Visualized Intraluminal Support (LVIS) devices for stent-assisted coil embolization of wide-necked intracranial aneurysms. MATERIALS AND METHODS: This was a prospective, multicenter, observational study of unruptured and ruptured intracranial aneurysms treated with the LVIS devices. Imaging and clinical data were independently analyzed respectively by CoreLab and Clinical Event Committee. Primary endpoints were clinical safety, effectiveness, and angiographic stability of the results at 6 and 18 months. RESULTS: Ten centers participated in the study; 102 patients were included and 90 patients (42.2% men, 57.8% women) were eventually analyzed, among which 27 (30.0%) had multiple aneurysms. Twenty-three (25.6%) were ruptured aneurysms, four of which (4.4%) were treated in the acute phase. One aneurysm was treated per patient; 92 LVIS and LVIS Jr devices were placed overall. The total aneurysm occlusion rate was 91.0% on immediate post-procedure angiograms, which remained unchanged at 6-month follow-up and was 92.4% at 18-month follow-up. One patient (1.1%) underwent retreatment between 6 and 18 months of follow-up. A modified Rankin score of 0 was documented for most cases immediately after the procedure (86.7%) and at 6-month (86.8%) and 18-month (83.3%) follow-up. The overall permanent morbidity rate at 18 months was 5.6% and the overall rate of events with sequelae related to the stent was 2.2%. The 18-month procedure-related mortality rate was 3.3%. No patient was deemed to require retreatment at 18-month follow-up. CONCLUSION: The LVIS/LVIS Jr endovascular devices are safe and effective in the treatment of ruptured and unruptured intracranial aneurysms, with acceptable complication rates, very high immediate total occlusion rates, and stable angiographic results.

Experimental evaluation of stent retrievers' mechanical properties and effectiveness.

BACKGROUND: Five randomized controlled trials recently appeared in the literature demonstrating that early mechanical thrombectomy in patients with acute ischemic stroke is significantly related to an improved outcome. Stent retrievers are accepted as the most effective devices for intracranial thrombectomy. OBJECTIVE: To analyze the mechanical properties of stent retrievers, their behavior during retrieval, and interaction with different clots and to identify device features that might correlate with the effectiveness of thrombus removal. MATERIALS AND METHODS: All stent retrievers available in France up to June 2015 were evaluated by mechanical and functional tests aimed at investigating the variation of their radial force and their behavior during retrieval. Devices were also tested during in vitro thrombectomies using white and red experimental thrombi produced with human blood. Functional tests and in vitro thrombectomies were conducted using a rigid 3D printed vascular model. RESULTS: Mechanical tests showed a variation in radial force during retrieval for each stent. A constant radial force during retrieval was related to continuous cohesion over the vessel wall and a higher rate of clot removal efficacy. All stent retrievers failed when interacting with white large thrombi (diameter ≥6 mm). CONCLUSIONS: None of the tested devices were effective in removing white clots of large diameter (≥6 mm). Constant radial force during retrieval allows constant cohesion to the vessel wall and pressure over the clot; such features allow for a higher rate of clot removal.

Mechanical thrombectomy with the Solitaire device in acute basilar artery occlusion.

AIMS: To evaluate the efficacy and safety of mechanical thrombectomy with the Solitaire FR device in revascularization of patients with acute basilar artery occlusion (ABAO) and to identify the predictive factors for clinical outcome. METHODS: This prospective single-center study included 31 patients with acute ischemic stroke attributable to ABAO treated within the first 24 h after onset of symptoms with the Solitaire device. Nineteen patients simultaneously received intravenous thrombolysis. Recanalization rates after stent retrieval were determined and the clinical outcome and mortality rate were assessed 180 days after treatment. RESULTS: The mean ±SD age of the patients was 61±17 years, the median prethrombectomy NIH Stroke Scale score was 38 (IQR 9-38) and the median Glasgow Coma Scale (GCS) score was 7 (IQR 4-14). Successful recanalization (TICI 3 or 2b) was achieved in 23 patients (74%). Five symptomatic intracranial hemorrhages were related to the procedure. Ten symptomatic distal migrations of thrombotic material occurred. A favorable outcome, defined as a modified Rankin Score (mRS) of 0-2, was observed in 35% of patients (11/31). Overall mortality rate was 32% (10/31). In the univariate analysis, elevated baseline glucose (p=0.008) was significantly associated with a poor outcome (mRS >2), whereas a tendency towards significance was observed with age (p=0.06), GCS on admission (p=0.07) and symptom-related lesions on T2 sequences (p=0.10). Patients with successful recanalization tended to have a better outcome (p=0.20). CONCLUSION: Mechanical thrombectomy with the Solitaire FR device can rapidly and effectively contribute to a high rate of recanalization and improve functional outcome in patients with ABAO and has an acceptable complication rate.

Solitaire FR thrombectomy system: immediate results in 56 consecutive acute ischemic stroke patients.

BACKGROUND AND PURPOSE: Prompt recanalization of cerebral arteries in patients diagnosed with acute ischemic stroke is known to be associated with a better clinical outcome. The aim of this study was to present our initial experience regarding the efficacy and safety of the Solitaire FR as a revascularization device. METHODS: 56 consecutive patients presenting with acute ischemic stroke underwent intra-arterial therapy using the Solitaire FR revascularization device. Immediate angiographic results and early clinical outcomes are presented. RESULTS: Solitaire FR was successful in achieving recanalization in 50 out of 56 patients (89%) with a final Thrombolysis in Cerebral Infarction score ≥2b. Five out of 56 patients had procedure related complications: two asymptomatic subarachnoid hemorrhages, two thromboembolic events and one symptomatic intracranial hemorrhage (PH2). Thirty patients (53.5%) demonstrated at discharge a National Institutes of Health Stroke Scale Score of ≤1 or an improvement of at least 10 points from baseline, and 26 patients (46%) had a modified Rankin Score ≤2. CONCLUSIONS: Solitaire FR is successful in achieving a high rate of arterial recanalization with a low complication rate. The Solitaire FR is a promising thrombectomy tool with a high degree of effectiveness, safety and ease of use.