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Incidence and outcome of procedural distal emboli using the Penumbra thrombectomy for acute stroke
Abstract
Background The Penumbra system is effective for recanalization of the primary arterial occlusion (PAO) in acute stroke. However, clinical outcomes are not as promising. The authors hypothesized that the formation of procedural distal emboli (PDE) during mechanical thrombectomy may lead to poorer patient outcomes.
Design/methods A retrospective review of patients with acute ischemic stroke treated with the Penumbra system was undertaken. Patients' outcome was evaluated by comparing discharge National Institute of Health stroke scale and modified Rankin score (mRS) of patients with and without PDE.
Results Out of 20 patients reviewed, recanalization of PAO was 100%. Six patients (30%) were confirmed to have PDE, of which two died (33.3%) and one (16.7%) had mRS of 2 or less. Of the 14 patients without PDE, three died (21.4%) and six (42.9%) had mRS of 2 or less. In the patient group who survived, mean National Institute of Health stroke scale decrease was only 2.3 in patients with PDE versus a decrease of 10.6 in patients without PDE.
Conclusions In spite of PAO recanalization, distal emboli formed subsequent to Penumbra thrombectomy may contribute to poorer clinical outcome in acute stroke patients.
... Procedural embolic complications can disrupt collateral blood flow, potentially leading to preventable tissue ischemia and even ischemia in previously unaffected regions. [23][24][25] These fragmented clots are linked to poor clinical outcomes, 2 3 consistent with our findings that patients experiencing distal embolization had worse outcomes at 90 days. ...
Background
Distal embolization is a frequent complication of mechanical thrombectomy (MT) for acute ischemic stroke, often leading to poor clinical outcomes. The vascular bifurcations represent a specialized anatomical location, thereby augmenting the complexity of MT. The specific factors contributing to distal embolization in this context have not been thoroughly explored. This study seeks to identify the factors associated with distal embolization during MT in patients with anterior circulation large vessel bifurcation occlusion stroke.
Methods
A retrospective analysis was conducted on patients who underwent MT for acute anterior circulation bifurcation occlusion stroke between January 2015 and December 2023. Baseline characteristics, procedural details, and clinical outcomes were assessed. Univariate and multivariable analyses were performed to identify predictors of distal embolization during MT.
Results
The study included 119 patients. Univariate analysis revealed significant associations between distal embolization and occlusion location, internal carotid artery (ICA) tortuosity, first-line thrombectomy strategy, and the number of device passes. Multivariate analysis identified ICA bifurcation occlusions (odds ratio (OR) 3.21, 95% confidence interval (CI) 1.188 to 8.672, P=0.021), stent retriever thrombectomy (SRT) (OR 6.177, 95% CI 1.77 to 21.555, P=0.004), and a higher number of device passes (OR 1.778, 95% CI 1.132 to 2.792, P=0.013) as independent predictors of distal embolization.
Conclusions
ICA bifurcation occlusion, the use of SRT, and an increased number of device passes are significant predictors of distal embolization during MT in patients with anterior circulation large vessel bifurcation occlusion strokes.
... Complete recanalization still cannot be obtained in a small proportion of patients due to the formation of thrombus fragmentation and secondary embolization (SE) during the procedure. Thrombus fragmentation and SE can reduce the anterior blood flow and often require more complex surgical maneuvers to relieve the obstruction, increasing the risk of hemorrhagic transformation (4). ...
Background and aims
Secondary embolization (SE) during mechanical thrombectomy (MT) for cerebral large vessel occlusion (LVO) could reduce the anterior blood flow and worsen clinical outcomes. The current SE prediction tools have limited accuracy. In this study, we aimed to develop a nomogram to predict SE following MT for LVO based on clinical features and radiomics extracted from computed tomography (CT) images.
Materials and methods
A total of 61 patients with LVO stroke treated by MT at Beijing Hospital were included in this retrospective study, of whom 27 developed SE during the MT procedure. The patients were randomly divided (7:3) into training (n = 42) and testing (n = 19) cohorts. The thrombus radiomics features were extracted from the pre-interventional thin-slice CT images, and the conventional clinical and radiological indicators associated with SE were recorded. A support vector machine (SVM) learning model with 5-fold cross-verification was used to obtain the radiomics and clinical signatures. For both signatures, a prediction nomogram for SE was constructed. The signatures were then combined using the logistic regression analysis to construct a combined clinical radiomics nomogram.
Results
In the training cohort, the area under the receiver operating characteristic curve (AUC) of the nomograms was 0.963 for the combined model, 0.911 for the radiomics, and 0.891 for the clinical model. Following validation, the AUCs were 0.762 for the combined model, 0.714 for the radiomics model, and 0.637 for the clinical model. The combined clinical and radiomics nomogram had the best prediction accuracy in both the training and test cohort.
Conclusion
This nomogram could be used to optimize the surgical MT procedure for LVO based on the risk of developing SE.
... deleterious products generated during the ischemic process, and microvascular occlusion after proximal recanalization-may have a role in tissue damage at different time points. [3][4][5] Most published studies evaluating infarct expansion in patients treated with EVT have assessed infarct volume at only 2 time points (pre-EVT and follow-up or early post-EVT and follow-up), precluding the possibility of individuating which part of the final infarct occurs early peri-intervention and which part develops later, after EVT. [6][7][8][9] Such knowledge could be relevant to the development of new therapeutic strategies. ...
BACKGROUND
We studied the evolution over time of diffusion weighted imaging (DWI) lesion volume and the factors involved on early and late infarct growth (EIG and LIG) in stroke patients undergoing endovascular treatment (EVT) according to the final revascularization grade.
METHODS
This is a prospective cohort of patients with anterior large artery occlusion undergoing EVT arriving at 1 comprehensive stroke center. Magnetic resonance imaging was performed on arrival (pre-EVT), <2 hours after EVT (post-EVT), and on day 5. DWI lesions and perfusion maps were evaluated. Arterial revascularization was assessed according to the modified Thrombolysis in Cerebral Infarction (mTICI) grades. We recorded National Institutes of Health Stroke Scale at arrival and at day 7. EIG was defined as (DWI volume post-EVT–DWI volume pre-EVT), and LIG was defined as (DWI volume at 5d–DWI volume post-EVT). Factors involved in EIG and LIG were tested via multivariable lineal models.
RESULTS
We included 98 patients (mean age 70, median National Institutes of Health Stroke Scale score 17, final mTICI≥2b 86%). Median EIG and LIG were 48 and 63.3 mL in patients with final mTICI<2b, and 3.6 and 3.9 cc in patients with final mTICI≥2b. Both EIG and LIG were associated with higher National Institutes of Health Stroke Scale at day 7 ( ρ =0.667; P <0.01 and ρ =0.614; P <0.01, respectively). In patients with final mTICI≥2b, each 10% increase in the volume of DWI pre-EVT and each extra pass leaded to growths of 9% (95% CI, 7%–10%) and 14% (95% CI, 2%–28%) in the DWI volume post-EVT, respectively. Furthermore, each 10% increase in the volume of DWI post-EVT, each extra pass, and each 10 mL increase in TMax6s post-EVT were associated with growths of 8% (95% CI, 6%–9%), 9% (95% CI, 0%–19%), and 12% (95% CI, 5%–20%) in the volume of DWI post-EVT, respectively.
CONCLUSIONS
Infarct grows during and after EVT, especially in nonrecanalizers but also to a lesser extent in recanalizers. In recanalizers, number of passes and DWI volume influence EIG, while number of passes, DWI, and hypoperfused volume after the procedure determine LIG.
... Despite major strides in reducing disability from large vessel occlusion strokes with stent retrievers (SRs), 72% of patients with intracranial ICA occlusion remain physically disabled [1]. A high first-pass complete reperfusion rate [9], short puncture-to-reperfusion time (PRT) [10], and low incidence of distal emboli [11] are associated with improved functional neurological recovery. ...
Background:
Balloon guide catheters (BGCs) have good performance in terms of radiological outcomes in acute ischemic thrombectomy. It is not uncommon for BGCs to be blocked by thrombi, especially in cases with acute intracranial internal carotid artery (ICA) occlusion. Our initial experience using repeat thrombectomy with a retrieval stent (RTRS) with continuous proximal flow arrest by BGC for acute intracranial ICA occlusion is presented.
Methods:
In patients with acute intracranial ICA occlusion treated with RTRS, clinical data, including the National Institutes of Health Stroke Scale (NIHSS) score at admission and modified Rankin Scale (mRS) score at 90 days, and procedural data, including the Extended treatment in Cerebral Infarction (eTICI) score, procedural time, and complications, were analyzed.
Results:
Thirty-two consecutive patients (12 men (37.5%); mean age: 73 years) were treated with RTRS using a BGC. The median NIHSS score was 19. The median puncture-to-reperfusion time was 46 minutes (range: 22-142 minutes). All patients were successfully revascularized; eTICI 2c or better recanalization was achieved in 30 (93.8%) patients. No procedure-related complications or symptomatic intracranial hemorrhage occurred. Two cases (6.3%) had distal emboli, but none had emboli to the anterior cerebral artery. Fourteen patients (43.8%) achieved a good outcome with an mRS score of 0-2 at 90 days, and 8 patients (25.0%) died.
Conclusions:
In patients with intracranial ICA occlusion, RTRS with proximal flow arrest by BGC is effective and safe, achieving good clinical and angiographic outcomes. This method may reduce the incidence of distal emboli in thrombectomy with stent retrievers.
... This generally occurs as the fibrin structures experience permanent/plastic deformation until full rupture and a portion of the tissue is ultimately broken. Clinical reports indicate that the creation of distal emboli can occur in 12-30% of stent retriever thrombectomy cases [44][45][46]. In our model, virtually varying the material properties of the clot (via changing the material parameters and FEA-SPH conversion point) enabled us to recapitulate such behaviour. ...
Stent retriever thrombectomy is a pre-eminent treatment modality for large vessel ischaemic stroke. Simulation of thrombectomy could help understand stent and clot mechanics in failed cases and provide a digital testbed for the development of new, safer devices. Here, we present a novel, in silico thrombectomy method using a hybrid finite-element analysis (FEA) and smoothed particle hydrodynamics (SPH). Inspired by its biological structure and components, the blood clot was modelled with the hybrid FEA–SPH method. The Solitaire self-expanding stent was parametrically reconstructed from micro-CT imaging and was modelled as three-dimensional finite beam elements. Our simulation encompassed all steps of mechanical thrombectomy, including stent packaging, delivery and self-expansion into the clot, and clot extraction. To test the feasibility of our method, we simulated clot extraction in simple straight vessels. This was compared against in vitro thrombectomies using the same stent, vessel geometry, and clot size and composition. Comparisons with benchtop tests indicated that our model was able to accurately simulate clot deflection and penetration of stent wires into the clot, the relative movement of the clot and stent during extraction, and clot fragmentation/embolus formation. In this study, we demonstrated that coupling FEA and SPH techniques could realistically model stent retriever thrombectomy.
... 1,2 Removing the clot in a fragmented manner increases the potential of embolization to new territories, a major contributing factor to poor neurologic outcomes due to additional brain infarction. [3][4][5] Despite the advancement in the second-generation mechanical thrombectomy devices, the rates of FPE remain low, as low as 29% in the recently reported Contact Aspiration vs Stent Retriever for Successful Revascularization (ASTER) trial. 6 Previous studies have demonstrated that a wide variety of occlusive clots can cause large-vessel occlusion, [7][8][9][10][11] and clot composition has been shown to have a significant impact on the success of mechanical thrombectomy procedures. ...
Background and purpose:
Previous studies have successfully created blood clot analogs for in vitro endovascular device testing using animal blood of various species. Blood components vary greatly among species; therefore, creating clot analogs from human blood is likely a more accurate representation of thrombi formed in the human vasculature.
Materials and methods:
Following approval from the Mayo Clinic institutional review board, human whole-blood and platelet donations were obtained from the blood transfusion service. Twelve clot analogs were created by combining different ratios of red blood cells + buffy coat, plasma, and platelets. Thrombin and calcium chloride were added to stimulate coagulation. Clot composition was assessed using histologic and immunohistochemical staining. To assess the similarities of mechanical properties to patient clots, 3 types of clot analogs (soft, elastic, and stiff) were selected for in vitro thrombectomy testing.
Results:
The range of histopathologic compositions produced is representative of clots removed during thrombectomy procedures. The red blood cell composition ranged from 8.9% to 91.4%, and fibrin composition ranged from 3.1% to 53.4%. Platelets (CD42b) and von Willebrand Factor ranged from 0.5% to 47.1% and 1.0% to 63.4%, respectively. The soft clots had the highest first-pass effect and successful revascularization rates followed by the elastic and stiff clots. Distal embolization events were observed when clot ingestion could not be achieved, requiring device pullback. The incidence rate of distal embolization was the highest for the stiff clots due to the weak clot/device integration.
Conclusions:
Red blood cell-rich, fibrin-rich, and platelet-rich clot analogs that mimic clots retrieved from patients with acute ischemic stroke were created in vitro. Differing retrieval outcomes were confirmed using in vitro thrombectomy testing in a subset of clots.
... [6] In previous studies, researchers have investigated embolic fragments in both clinical and in vitro experiments. [7][8][9] We hypothesized that the distal release of embolic particles during endovascular procedures is lesser with the ASAP [2] technique than with any other techniques such as CAPTIVE [3] and ARTS. [4] Furthermore, we predicted that the ASAP technique could achieve the highest rate of recanalization against any clot mechanics 59,220 390 0 〇; success, ×; failure, SR (B−); Stent Retrieving without proximal flow arrest by a guiding Balloon, SR (B+); Stent Retrieving with proximal flow arrest by a guiding Balloon compared with other techniques, including the ADAPT. ...
Background:
This study was conducted to evaluate various devices and techniques for endovascular thrombectomy that can reduce the risk of intraprocedural distal embolism in a preliminary in vitro setting with different types of thrombi.
Materials and methods:
Endovascular clot retrieval was performed in a vascular model with collateral circulation. White and red thrombi were prepared using whole blood collected from a pig. A Direct Aspiration First Pass Technique (ADAPT), simple stentretrieving with and without proximal flow arrest by a guiding balloon (SR [B+] and SR [B±]), the AspirationRetriever Technique for Stroke (ARTS), and A stentretrieving into an Aspiration catheter with Proximal balloon (ASAP) were performed three times, respectively. The saline samples that were collected at the distal side during each procedure were examined using a particle counter. The particles were counted and categorized into three groups based on size (100 μm).
Results:
SR (B-) and SR (B+) could not achieve complete retrieval of the clot, especially using the white thrombus. ASAP was the only method that was able to retrieve the clots in all attempts. In both clot types, SR (B-), SR (B+), and ARTS, which involved a temporary flow restoration through stent deployment, demonstrated the migration of a greater number of particles measuring >100 μm in size than that shown by ADAPT and ASAP.
Conclusions:
ASAP was the safest method in terms of intraprocedural clot migration among the five methods evaluated in this study. Temporary flow restoration through stent deployment may affect the dangerous distal clot migration.
... [91,95] These clots can block collateral flow to potentially salvageable tissue or even cause ischemia in a previously unaffected territory. [87,[96][97][98] The presence of these fragmented clots have been shown to be associated with worse clinical outcomes. [96,99] Other causes of distal emboli are the use of conscious sedation, posterior circulation occlusions and increased thrombus length. ...
Complications and difficult access are encountered during acute stroke thrombectomy. Description of such complications and management strategies for relapsing occlusions, rigid (fibrin-rich) clots, and clot migration/showering are discussed in detail.
... Embolization into a new territory was observed in one patient (2.8%), suggesting that the mentioned features of the device might confer protection against this periprocedural complication since previously reported rates range from 6.6 to 8.5%. 19,23,24 Longer series should explore this trend. Although one of the two dissections was unrelated to the ANA device, this event should be monitored to confirm that it remains in line with previously published rates (2%). ...
Introduction
The ANA™ (Anaconda Biomed) thrombectomy system is a novel stroke thrombectomy device comprising a self-expanding funnel designed to reduce clot fragmentation by locally restricting flow while becoming as wide as the lodging artery. Once deployed, ANA allows distal aspiration in combination with a stentretriever (SR) to mobilize the clot into the funnel where it remains copped during extraction. We investigate safety and efficacy of ANA™ in a first-in-man study.
Methods
Prospective data was collected on 35 consecutive patients treated as first line with ANA™ at a single centre. Outcome measures included per-pass reperfusion scores, symptomatic intracerebral hemorrhage (sICH), NIHSS at day 5, and mRS at 90 days.
Results
Median NIHSS was 12(9-18). Sites of primary occlusion were: 5 ICA, 15 M1-MCA, 15 M2-MCA. Primary performance endpoint, mTICI 2b-3 within 3 passes without rescue therapy was achieved in 91.4% (n = 32) of patients; rate of complete recanalization (mTICI 2c-3) was 65.7%. First pass complete recanalization rate was 42.9%, and median number of ANA passes 1(IQR: 1-2). In 17.1% (n = 6) rescue treatment was used; median number of rescue passes was 2(1-7), leading to a final mTICI2b-3rate of 94.3% (n = 33). There were no device related serious adverse events, and rate of sICH was 5.7% (n = 2). At 5 days median NIHSS was 1 (IQR 1-6) and 90 days mRS 0-2 was achieved in 60% of patients.
Conclusions
In this initial clinical experience, the ANA™ device achieved a high rate of complete recanalization with a good safety profile and favourable 90 days clinical outcomes.
... [9] Balloon guide catheters (BGCs) with a large internal diameter (ID) and a large outer diameter (OD) are used to prevent distal embolization of thrombus fragments during MT. [10][11][12][13][14][15][16] Trans-brachial or radial access using a BGC, however, is not standard [17] and BGCs were used in only 6 of 18 trans-radial cases. [9] To prevent procedure time extension due to difficulties in navigating guide catheters through the transfemoral route, we implemented computed tomographic angiography (CTA) to evaluate the anatomical conditions of the aortic arch before MT. ...
BACKGROUND AND PURPOSE: When the femoral approach for mechanical thrombectomy (MT) in acute ischemic stroke (AIS) is limited, trans-brachial or-radial access is an alternative. However, transbrachial insertion of a 9Fr (outer diameter [OD]) balloon guide catheter (BGC) into the carotid artery is not feasible. Computed tomographic (CT) angiography (CTA) may provide vascular anatomical information for successful insertion. We investigated CTA anatomical features for successful transbrachial insertion of a 9Fr BGC into the carotid artery.
MATERIALS AND METHODS: We analyzed AIS patients who underwent CTA and transbrachial MT using a 9Fr BGC between 2014 and 2016. We evaluated the successful insertion rate and CT angiographic anatomical features.
RESULTS: Twenty-four patients met our inclusion criteria. We achieved successful insertion in 18 (75%) of 24 cases: 7 (58.3%) of 12 for left carotid arteries and 11 (91.7%) of 12 for right carotid arteries. Successful insertion was achieved in 4 of 4 bovine aortic arch for left carotid occlusion and in 3 of 8 nonbovine aortic arches for left carotid occlusion. We achieved successful insertion in 3 nonbovine cases with takeoff angles ≥23° and failed insertion in 5 cases with takeoff angles
... Endovascular thrombectomy is currently the most favored treatment for acute ischemic stroke or most large vessel occlusion strokes (Todo et al. 2013;Costalat et al. 2012). A modifiable factor to improve outcome of carotid artery stenting is the avoidable procedural release of embolic particulate of various sizes (Yang et al. 2016). ...
Optimal strength and stability of blood clots are keys to hemostasis and in prevention of hemorrhagic or thrombotic complications. Clots are biocomposite materials composed of fibrin network enmeshing platelets and other blood cells. We have previously shown that the storage temperature of platelets significantly impacts clot structure and stiffness. The objective of this work is to delineate the relationship between morphological characteristics and mechanical response of clot networks. We examined scanning electron microscope images of clots prepared from fresh apheresis platelets, and from apheresis platelets stored for 5 days at room temperature or at 4 °C, suspended in pooled plasma. Principal component analysis of nine different morphometric parameters revealed that a single principal component (PC1) can distinguish the effect of platelet storage on clot ultrastructure. Finite element analysis of clot response to uniaxial strain was used to map the spatially heterogeneous distribution of strain energy density for each clot. At modest deformations (25% strain), a single principal component (PC2) was able to predict these heterogeneities as quantified by variability in strain energy density distribution and in linear elastic stiffness, respectively. We have identified structural parameters that are primary regulators of stress distribution, and the observations provide insights into the importance of spatial heterogeneity on hemostasis and thrombosis.
... The actual incidence of emboli during a thrombectomy procedure could be much more than previously thought [77,89] as during a thrombectomy, a large portion of the thrombus fragments that break off are very small and not visible on standard digital subtracted angiography, as seen in in vitro experiments. These tiny emboli can obstruct collateral flow to the salvageable ischemic penumbra, induce inflammatory injury at the capillary circulation level or even cause infarcts in a previously unaffected vascular territory [73,[90][91][92]. The presence of these fragmented clots has been shown to be associated with worse clinical outcomes [90,93]. ...
Thrombectomy is a technique that has completely changed the management of acute stroke and current devices have shown that they can achieve upwards of 90% successful recanalization in selected cohorts. However, despite the effectiveness of these devices, there are a proportion of patients who still fail to achieve reperfusion of the affected vascular territory and an even larger portion of patients who have poor functional outcomes in spite of successful recanalization. There are no guidelines on how to treat these patients when such failures occur. In an effort to understand the underpinnings of how failed thrombectomy occurs, we extensively reviewed the current literature in clot properties, vascular access problems, stroke pathogenic mechanisms, embolic complications, failed procedures and pre-procedural imaging. A short summary of each of these contentious areas are provided and the current state of the art. Together these elements give a cohesive overview of the mechanisms of failed thrombectomy as well as the controversies facing the field. New techniques and devices can then be developed to minimize such factors during stroke thrombectomy.
... Procedurerelated embolic complications have been noted with various thrombectomy devices [7][8][9][10]. These clots can block collateral flow to potentially salvageable tissue or even cause ischemia in a previously unaffected territory [11][12][13][14]. The presence of these fragmented clots has been shown to be associated with worse clinical outcomes [12,15]. ...
Background:
Distal embolization or movement of the thrombus to previously uninvolved vasculature are feared complications during stroke thrombectomy. We looked at associated factors in a consecutive series of patients who underwent thrombectomy with the same endovascular device.
Methods:
We included all patients with acute ischemic stroke in the anterior or posterior circulation, who underwent thrombectomy with the same thrombectomy device for acute stroke from 2013 to 2016. Distal embolization was defined as any movement of the thrombus into a previously uninvolved portion of the cerebral vasculature or the presence of thrombotic material further downstream in the affected vessel, which occurred after the initial angiogram. We studied patient-related as well as technical factors to determine their association with distal emboli.
Results:
In this study 167 consecutive acute stroke patients treated with the emboTrap® device (Cerenovus, Irvine, CA, USA) were included with a median National Institutes of Health Stroke Scale (NIHSS) of 15 (range 2-30) and mean age of 67 years (SD 13.1 years). Of the patients in our cohort 20 (11.9%) experienced distal emboli, with 2.3% into a new territory and 9.6% into a territory distal to the primary occlusion. On univariate analysis, age, intravenous tissue plasminogen activator (tPA), posterior circulation occlusions, and general anesthesia were associated with distal emboli. On multivariate analysis, only posterior circulation occlusions (odds ratio OR 4.506 95% confidence interval CI 1.483-13.692, p = 0.008) were significantly associated with distal emboli. Distal embolization was not significantly associated with worse functional outcomes at 3 months, increased mortality or increased bleeding risk.
Conclusion:
Posterior circulation occlusions were significantly associated with distal emboli during thrombectomy, possibly due to the lack of flow arrest during such procedures. New techniques and devices should be developed to protect against embolic complications during posterior circulation stroke thrombectomy.
... Subsequently, in December 2007, the FDA approved the Penumbra endovascular suction device (Penumbra, Inc.) [4,5]. A commonality among various studies was that Penumbra caused fewer hemorrhagic complications than MERCI, likely due to a reduction in the mechanical trauma to the artery, but may result in worse neurological outcomes because of multiple thromboemboli sent distally [6]. The Solitaire-FR retrievable stent (ev3/Covidien), member of the newest line of ischemic stroke devices referred to as stent retrievers, was the first such device to be approved by the FDA (approved in March 2012). ...
Background:
Several mechanical thrombectomy (MT) devices have been designed with the goal of improving the recanalization rates of major intracranial artery occlusions.
Objective:
In this single-center experience, we analyzed the acute ischemic stroke (AIS) treatment with Primary MT; safety and efficacy and clinical results in our patients with large vessel occlusion (LVO).
Methods:
During a five-year period (from September 2011 to July 2016), out of 996 patients who presented to our center with a diagnosis of AIS, 113 (11.4%) patients (55 men and 58 women) underwent primary mechanical recanalization within three hours from onset of signs and symptoms for anterior and 12 hours for posterior circulation (with computer tomography angiography/perfusion ELVO). Successful recanalization (thrombolysis in cerebral infarction 2b-3), good outcome (modified Rankin scale score 0-2) and overall mortality rate, and symptomatic intracranial hemorrhage [sICH: parenchymal hematoma Type 1 or Type 2; National Institutes of Health Stroke Scale (NIHSS) score increment ≥4 points] were prospectively assessed.
Results:
The mean age of the patients was 62 ± 11.73 years, with a baseline mean admission NIHSS score of 16.7 ± 3.2. The mean time from onset to puncture (time to treatment) was 208.55 ± 53.49. Successful recanalization was achieved in 104 (92%) cases. Good outcome was observed in 89 (78.8%) patients, and mortality was 11.5% (n= 13). sICH occurred in five (4.4%) patients.
Conclusion:
MT, within the first 4.5 hours, as primary treatment of acute LVO stroke provides high rate of recanalization and favorable clinical outcomes with low procedural complications.
... 6 7 The presence of fragmented clots is a predictor of poor outcome 8 as disrupted clots can block collateral flow to potentially salvageable tissue or cause distal embolization in a previously unaffected area. [9][10][11][12] Procedural release of embolic particulate is a modifiable risk. ...
Background:
Formation of clot fragments during mechanical thrombectomy for acute ischemic stroke can occlude the distal vasculature, which may reduce the rate of good clinical outcome.
Objective:
To examine the hypothesis that distal embolization can be reduced using stent retriever thrombectomy in combination with Lazarus Cover technology.
Methods:
Hard, fragment-prone clots were used to create middle cerebral artery occlusions in a vascular phantom. Three different treatment strategies using Solitaire FR included: group 1-proximal flow control with an 8F balloon guide catheter (BGC), group 2-thrombectomy through a 6F conventional guide catheter (CGC), and group 3-a similar thrombectomy procedure to group 2 but including the Lazarus Cover device. The primary endpoint was distal emboli quantified by the number and size of the clot debris.
Results:
The Cover-assisted stent retriever thrombectomy significantly reduced the generation of clot fragments >200 μm as compared with thrombectomy with a CGC, and was similar to the BGC group. Particle size distribution <200 μm was similar across the groups. All groups were associated with high rates of recanalization, with only one failed recanalization with partial clot retention after three passes in one experiment of stent retriever thrombectomy through a CGC. Use of the adjunctive Cover device did not prolong the procedure as compared with control groups.
Conclusions:
For a fragment-prone clot, Solitaire thrombectomy in conjunction with the Cover device may lower the risk of distal embolization and is comparable to BGC-protected embolectomy.
... Currently, stentrievers are the most appropriate first-line endovascular intervention supported by the literature, with technical results that seem superior to most other techniques and devices. [42][43][44][45] Recently, stentrievers have been demonstrated to improve functional outcomes compared with either IA-tPA or Merci Retriever. 46 This suggests a direct translation from technical success to clinical success. ...
Current guidelines advocate intravenous thrombolysis for patients with ischemic stroke <4.5 hours from onset without additional imaging beyond noncontrast computed tomography (CT) of the brain.1 Rapid administration of intravenous tissue-type plasminogen activator (IV-tPA) will reduce disability. Treatment of patients within 3 hours has an odds ratio of 1.53 (95% confidence interval, 1.26–1.86) for a favorable outcome (modified Rankin scale [mRS], 0–2) at 3 months.2 However, this represents an absolute increase of 9% compared with placebo and is available to a minority of patients with ischemic stroke because of the rigid time constraints.3 Modern stroke imaging grants unprecedented access to the pathophysiology in individual patients with stroke. Time remains of key importance with respect to patient outcomes. However, it is now possible to not only routinely visualize the causative occlusion, but also estimate the ischemic core, the penumbral tissue at risk if reperfusion does not occur, and the state of the collateral blood supply. The current focus of Acute Ischemic Stroke (AIS) intervention should be to achieve reperfusion of the penumbra. Recent trials point to potential avenues to improve patient access by imaging-based patient selection and the importance of rapid and complete reperfusion of the penumbra.
Three parenchymal vascular states exist in varying proportions in each AIS patient. These are the ischemic core, the penumbra, and a region of benign oligemia.4,5 Separating the penumbra from the ischemic core is of critical importance in guiding stroke therapy. So too is separating the penumbra from the region of benign oligemia. By definition, the penumbra is the region of tissue that is at risk of being recruited into the ischemic core. Thus, the penumbra is the principal target for reperfusion and, therefore, should dictate patient selection. Given the progressive nature of ischemic stroke, establishing the continued existence of …
Introduction
Mechanical thrombectomy (MT) with combined treatment including both a stent retriever and distal aspiration catheter may improve recanalization rates in patients with acute ischemic stroke (AIS) due to large vessel occlusion (LVO). Here, we evaluated the effectiveness and safety of the REACT aspiration catheter used with a stent retriever.
Methods
This prospective study included consecutive adult patients who underwent MT with a combined technique using REACT 68 and/or 71 between June 2020 and July 2021. The primary endpoints were final and first pass mTICI 2b-3 and mTICI 2c-3 recanalization. Analysis was performed after first pass and after each attempt. Secondary safety outcomes included procedural complications, symptomatic intracranial hemorrhage (sICH) at 24 h, in-hospital mortality, and 90-day functional independence (modified Rankin Scale [mRS] 0–2).
Results
A total of 102 patients were included (median age 78; IQR: 73–87; 50.0% female). At baseline, median NIHSS score was 19 (IQR: 11–21), and ASPECTS was 9 (IQR: 8–10). Final mTICI 2b-3 recanalization was achieved in 91 (89.2%) patients and mTICI 2c-3 was achieved in 66 (64.7%). At first pass, mTICI 2b-3 was achieved in 55 (53.9%) patients, and mTICI 2c-3 in 37 (36.3%). The rate of procedural complications was 3.9% (4/102), sICH was 6.8% (7/102), in-hospital mortality was 12.7% (13/102), and 90-day functional independence was 35.6% (36/102).
Conclusion
A combined MT technique using a stent retriever and REACT catheter resulted in a high rate of successful recanalization and first pass recanalization in a sample of consecutive patients with AIS due to LVO in clinical use.
Background
The Advanced Neurovascular Access (ANA) thrombectomy system is a novel stroke thrombectomy device comprising a self-expanding funnel designed to reduce clot fragmentation by locally restricting flow while becoming as wide as the lodging artery. Once deployed, the ANA device allows distal aspiration combined with a stent retriever to mobilize the clot into the funnel where it remains copped during extraction. We investigated the safety and efficacy of ANA catheter system.
Methods
SOLONDA (Solitaire in Combination With the ANA Catheter System as Manufactured by Anaconda) was a prospective, open, single-arm, multicenter trial with blinded assessment of the primary outcome by an independent core lab. Patients with anterior circulation vessel occlusion admitted within 8 hours from symptom onset were eligible. The primary end point was successful reperfusion (modified Thrombolysis in Cerebral Infarction score 2b–3) with ≤3 passes of the ANA device in combination with stent retriever, before the use of rescue therapy in the intention to treat population. Primary predefined analysis was noninferiority as compared to the performance end point observed in HERMES (High Effective Reperfusion Using Multiple Endovascular Devices).
Results
After enrollment of 74 patients, an interim analysis was conducted, and the trial Steering Committee decided to terminate recruitment due to safety and performance objectives were reached. Mean age was 71.6 (SD 8.9) years, 46.6% women and median National Institutes of Health Stroke Scale on admission 14 (interquartile range, 10–19). Successful reperfusion within 3 passes before rescue therapy was achieved in 60/72 (83.3% [95% CI, 74.7%–91.9%]) with a rate of complete reperfusion (modified Thrombolysis in Cerebral Infarction score 2c–3) of 60% (95% CI, 48.4%–71.1%; 43/72 patients). After noninferiority was confirmed ( P <0.01), the ANA device also showed superiority in the rate of successful reperfusion with ≤3 passes ( P =0.02). First-pass successful recanalization rate was 55.6% (95% CI, 44.1%–67.0%), with a first-pass complete recanalization rate of 38.9% (95% CI, 27.6%–50.1%). Rescue therapy to obtain a modified Thrombolysis in Cerebral Infarction score 2b–3 was needed in 12/72 (17%) patients. At 90 days, the rate of favorable functional outcome (modified Rankin Scale score 0–2) was 57.5% (95% CI, 46.2%–68.9%), and the rate of excellent functional outcome (modified Rankin Scale score 0–1) was 45.2% (95% CI, 33.8%–56.6%). The rate of severe adverse device related was 1.4%.
Conclusions
In this clinical experience, the ANA device achieved a high rate of complete recanalization with a preliminary good safety profile and favorable 90 days clinical outcomes.
PurposeThe first-pass effect during mechanical thrombectomy improves clinical outcomes regardless of first-line treatment approach, but current success rates for complete clot capture with one attempt are still less than 40%. We hypothesize that the ThrombX retriever (ThrombX Medical Inc.) can better engage challenging clot models during retrieval throughout tortuous vasculature in comparison with a standard stent retriever without increasing distal emboli.Materials and Methods
Thrombectomy testing with the new retriever as compared to the Solitaire stent retriever was simulated in a vascular replica with hard and soft clot analogs to create a challenging occlusive burden. Parameters included analysis of distal emboli generated per clot type, along with the degree of recanalization (complete, partial or none) by retrieval device verified by angiography.ResultsThe ThrombX device exhibited significantly higher rates of first-pass efficacy (90%) during hard clot retrieval in comparison with the control device (20%) (p < 0.009), while use of both techniques during soft clot retrieval resulted in equivalent recanalization. The soft clot model generated higher numbers of large emboli (>200 μm) across both device groups (p = 0.0147), and no significant differences in numbers of distal emboli were noted between the ThrombX and Solitaire techniques.Conclusions
Irrespective of clot composition, use of the ThrombX retriever demonstrated high rates of complete recanalization at first pass in comparison with a state-of-the-art stent retriever and proved to be superior in the hard clot model. Preliminary data suggest that risk of distal embolization associated with the ThrombX system is comparable to that of the control device.
Introduction/Purpose
Achieving complete reperfusion from a single mechanical thrombectomy attempt, termed First Pass Effect (FPE), is associated with significantly improved outcomes. Increasing the lumen of aspiration catheters to 6Fr has previously been shown to increase the reperfusion rates in comparison to smaller lumen catheters. We evaluated the performance of a novel large bore (0.088’’ ID) 8Fr aspiration catheter (Millipede 088, Perfuze Ltd.) and compared its performance against current industry standard 6Fr aspiration catheters (ACE68, Penumbra and SOFIA Plus, Microvention) in an in-vitro human vasculature model.
Methods
Following National University of Ireland Research Ethics committee approval human whole blood and platelet donations were obtained from the Irish Blood Transfusion Service. Three clot analogue phenotypes representative of clots retrieved from patients were created; Red Blood Cell-Rich, Mixed and Fibrin/Platelet-Rich. Histopathological analysis was performed using Martius Scarlet Blue (MSB) staining to confirm clot composition. The in-vitro model comprised a peristaltic pump, aortic arch and circle of Willis. Flow rates and pressure were controlled to replicate in-vivo conditions. Clot analogues of each phenotype were inserted into the ICA and lodged under pulsatile flow. Clot volume was optimized to mimic the clinical scenario; 10 mm clots reliably lead to a Distal M1+MCA Bifurcation Occlusion and 20 mm clots reliably lead to an ICA-T + Proximal M1 occlusion covering both the Posterior Communicating Artery and Anterior Cerebral Artery. Five replicates of each test were performed. Endpoints were FPE and Second Pass Reperfusion Success (>90% Retrieved).
Results
Histological composition was confirmed as RBC-Rich (RBCs:92.9%, WBCs:0.1%, Fibrin/Platelets:7.0%), Mixed (RBCs:79.7%, WBCs:0.3%, Fibrin/Platelets:20.0%) and Fibrin/Platelet-Rich (RBCs:51.8%, WBCs:0.3%, Fibrin/Platelets:47.9%). The 8Fr (Millipede 088) catheter performed better for each clot phenotype and in both occlusion locations (ICA-T & M1) compared to the 6Fr (0.068’’ & 0.070’’ ID) devices. In 10 mm M1+Bifurcation occlusions the 8Fr catheter achieved 100% FPE compared to an average of 40% in 6Fr devices (p>0.001*). In longer 20 mm ICA-T+Proximal M1 occlusions the Millipede 088 achieved 100% removal success within two passes in each clot phenotype compared to an average of 27% in the 6Fr devices (p>0.001*).
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Abstract E-018 Figure 1 Comparison of the First and Second Pass Reperfusion Success Rates of the novel 8Fr Millipede 088 Catheter versus the Standard 6Fr Catheters in (A) M1+Bifurcation and (B) ICA-Terminus Occlusions. N=5 Replicates in all tests
Conclusions
A novel 8Fr aspiration catheter demonstrates superiority over 6Fr aspiration catheters for each clot phenotype at the most common sites of occlusion in an in-vitro model.
Disclosures
S. Fitzgerald
1; C; Perfuze Ltd.
D. Ryan
None.
L. Mullins
4; C; Perfuze Ltd. 5; C; Perfuze Ltd.
J. Thornton
2; C; Perfuze Ltd. 4; C; Perfuze Ltd.
R. Nogueira
2; C; Perfuze Ltd. 4; C; Perfuze Ltd.
Background
Larger bore aspiration catheters are expected to significantly improve the speed and completeness of acute stroke revascularization.
Objective
To evaluate the navigability and clot retrieval performance of a novel 8Fr aspiration catheter, Millipede 088 (Perfuze Ltd), using fresh-frozen cadavers and an in vitro thrombectomy model, respectively.
Methods
Cadaveric study: Transfemoral catheterization of the intracranial arteries was performed in six cadavers, allowing evaluation of navigation to 12 middle cerebral arteries (MCAs) and six basilar arteries. Commercially available 6Fr aspiration catheters (SOFIA Plus, Microvention) were used as controls. In vitro study: Three human blood clot phenotypes were created; red blood cell-rich, mixed, and fibrin/platelets-rich. Two clot sizes, resulting in occlusion of the internal carotid artery (ICA) and MCA-M1 were investigated. Endpoints were first-pass effect (FPE), first-pass complete ingestion, and second-pass recanalization.
Results
Cadaveric study: Both the Millipede 088 and SOFIA Plus devices reached the distal MCA-M1 and the basilar artery in 10/12 and 2/2 of the navigation attempts, respectively. In the two instances of unsuccessful navigation, neither device was able to cross the ophthalmic artery. In vitro study: In 10 mm long M1 occlusions, Millipede 088 achieved 100% FPE versus 40% for 6Fr devices (p>0.001). In 20 mm long ICA occlusions, Millipede 088 achieved 100% removal success within two passes in each clot phenotype compared with an average of 27% for 6Fr devices (p>0.001).
Conclusions
Navigation of the Millipede 088 catheter to the MCA-M1 and basilar artery is feasible in a cadaver model. Millipede 088 demonstrates superiority over 6Fr aspiration catheters for three representative clot phenotypes at the most common sites of occlusion in an in vitro vasculature model.
In 2015, multiple randomized clinical trials showed an unparalleled treatment benefit of stent-retriever thrombectomy as compared to standard medical therapy for the treatment of a large artery occlusion causing acute ischemic stroke. A short time later, the HERMES collaborators presented the patient-level pooled analysis of five randomized clinical trials, establishing class 1, level of evidence A for stent-retriever thrombectomy, in combination with intravenous thrombolysis when indicated to treat ischemic stroke. In the years following, evidence continues to mount for expanded use of this therapy for a broader category of patients. The enabling technology that changed the tide to support endovascular treatment of acute ischemic stroke is the stent-retriever. This review summarizes the history of intra-arterial treatment of stroke, introduces the biomechanics of embolus extraction with stent-retrievers, describes technical aspects of the intervention, provides a description of hemodynamic implications of stent-retriever embolectomy, and proposes future directions for a more comprehensive, multi-modal endovascular approach for the treatment of acute ischemic stroke.
Background:
Intravenous recombinant tissue plasminogen activator (IV rt-PA) prior to thrombectomy may reduce the risk of intraprocedural distal embolization in acute ischemic stroke patients.
Methods:
We analyzed the diffusion-weighted imaging acquired with 1.5- or 3-T magnetic resonance imaging (MRI) scans obtained within 24 hours of thrombectomy in consecutive acute ischemic stroke patients. An independent physician identified distal embolization, defined as discrete foci of restricted diffusion independent of the primary area of infarction on MRI scan. Patients were stratified based on whether they had or did not receive IV rt-PA prior to thrombectomy.
Results:
Distal embolization was seen in 59 (ipsilateral in 56) of 63 patients (mean age ± SD; 64.6 ± 15.3 years) who underwent thrombectomy (mean number 8.6; range 0-32). There was no difference in mean number of ipsilateral hemispheric distal embolization between the 2 groups (7.9 ± 6.1 versus 7.5 ± 7.6, P = .82). After adjusting for age, admission National Institutes of Health Stroke Scale score, the time interval between symptom onset and thrombectomy, there was no association between receiving IV rt-PA prior to thrombectomy and number of ipsilateral distal emboli (P = .90). There was no relationship between the number of ipsilateral emboli and rates of favorable outcome after adjusting for other confounders (adjusted odds ratio 1.0; 95% confidence interval .89 - 1.0; P = .40).
Conclusions:
Although distal embolization is very common after thrombectomy, IV rt-PA prior to procedure does not reduce the risk of intraprocedural distal embolization.
Disrupted clots that form during endovascular treatment for acute ischemic stroke can cause distal embolization. It is not easy to recanalize occluded vessels resulting from distal emboli. In particular, endovascular treatment of distal A2 emboli is very challenging because it is difficult to access such a distal location and maintain microcatheter stability throughout the procedure. We report a case of successful recanalization of A2 occlusion caused by procedural-induced distal emboli through a proximal and distal supporting technique.
Purpose
The purpose of this article is to assess the efficacy and safety of manual aspiration thrombectomy (MAT) using a Penumbra catheter in patients with anterior cerebral artery (ACA) occlusions.
Materials and methods
From January 2012 to March 2016, 16 patients underwent MAT with Penumbra catheters using a proximal and distal supporting technique to treat ACA occlusions. We evaluated immediate angiographic results and clinical outcomes by reviewing patient electrical medical records.
Results
Of these patients, 11 had a complete obstruction of the distal internal carotid artery (ICA) and five had ACA and middle cerebral artery (MCA) occlusions. All patients achieved successful recanalization of the distal ICA or MCA (Thrombolysis in Cerebral Infarction (TICI) grade ≥2b). Overall the recanalization rate for ACA occlusions (TICI grade≥2b) was 93.7% (15/16). The median procedure time was 45 minutes (range: 35–65 minutes). No patients were observed to have a procedure-related subarachnoid hemorrhage. Four patients (25.0%) died during hospitalization because of massive symptomatic hemorrhage, brain edema, or herniation. At discharge, the median NIHSS score for surviving patients was 6 (range: 1–17). Five patients had favorable clinical outcomes (modified Rankin scale ≤2).
Conclusion
MAT appears to be safe and successfully achieves recanalization in patients with ACA occlusions.
There is a discrepancy in clinical outcomes and the achieved recanalization rates with stent retrievers in the endovascular treatment of ischemic stroke. It is our hypothesis that procedural release of embolic particulate may be one contributor to poor outcomes and is a modifiable risk. The goal of this study is to assess various treatment strategies that reduce the risk of distal emboli.
Mechanical thrombectomy was simulated in a vascular phantom with collateral circulation. Hard fragment-prone clots (HFC) and soft elastic clots (SECs) were used to generate middle cerebral artery (MCA) occlusions that were retrieved by the Solitaire FR devices through (1) an 8 Fr balloon guide catheter (BGC), (2) a 5 Fr distal access catheter at the proximal aspect of the clot in the MCA (Solumbra), or (3) a 6 Fr guide catheter with the tip at the cervical internal carotid artery (guide catheter, GC). Results from mechanical thrombectomy were compared with those from direct aspiration using the Penumbra 5MAX catheter. The primary endpoint was the size distribution of emboli to the distribution of the middle and anterior cerebral arteries.
Solumbra was the most efficient method for reducing HFC fragments (p<0.05) while BGC was the best method for preventing SEC fragmentation (p<0.05). The risk of forming HFC distal emboli (>1000 µm) was significantly increased using GC. A non-statistically significant benefit of direct aspiration was observed in several subgroups of emboli with size 50-1000 µm. However, compared with the stent-retriever mechanical thrombectomy techniques, direct aspiration significantly increased the risk of SEC fragmentation (<50 µm) by at least twofold.
The risk of distal embolization is affected by the catheterization technique and clot mechanics.
Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
Unlabelled:
OBJECT.: There is limited information regarding patient outcomes following interventions for stroke during the window for endovascular therapy. Studies have suggested that recently approved stent retrievers are safer and more effective than earlier-generation thrombectomy devices. The authors compared cases in which the Solitaire-FR device was used to those in which a MERCI or Penumbra device was used.
Methods:
This study is a single-center retrospective review of 102 consecutive cases of acute stroke in which patients were treated with mechanical thrombectomy devices between 2007 and 2013. Multivariate models, adjusted for confounding factors, were used to investigate functional independence (modified Rankin Scale [mRS] score ≤ 2, and successful reperfusion (thrombolysis in cerebral infarction [TICI] score ≥ 2b).
Results:
Thrombectomy device had a significant impact on functional independence (mRS score ≤ 2) at discharge from the hospital (p = 0.040). Solitaire-FR treatment resulted in significantly more patients being discharged as functionally independent in comparison with MERCI treatment (p = 0.016). A multivariate model found the use of Solitaire-FR to improve the odds of good clinical outcome in comparison with prior-generation devices (OR 6.283, 95% CI 1.785-22.119, p = 0.004). Additionally, the use of Solitaire-FR significantly increased the odds of successful reperfusion (OR 3.247, 95% CI 1.160-9.090, p = 0.025).
Conclusions:
The stent retriever Solitaire-FR significantly improved the odds of functional independence and successful revascularization of the arterial tree. New interventional technology for stroke continues to mature, but randomized trials are needed to establish the actual benefit to specific patient populations.
Abstract
BACKGROUND AND PURPOSE:
The purpose of this clinical evaluation was to assess the safety and effectiveness of the Penumbra System in the revascularization of patients presenting with acute ischemic stroke secondary to intracranial large vessel occlusive disease.
METHODS:
In this prospective, multicenter, single-arm study, 125 patients with neurological deficits as defined by a National Institutes of Health Stroke Scale score > or =8, presented within 8 hours of symptom onset, and an angiographic occlusion (Thrombolysis In Myocardial Infarction [TIMI] Grade 0 or 1) of a treatable large intracranial vessel were enrolled. Patients who presented within 3 hours from symptom onset had to be ineligible or refractory to recombinant tissue plasminogen activator therapy. All patients were followed clinically for 90 days postprocedure.
RESULTS:
A total of 125 target vessels in 125 patients were treated by the Penumbra System. Postprocedure, 81.6% of the treated vessels were successfully revascularized to TIMI 2 to 3. There were 18 procedural events reported in 16 patients (12.8%), 3 patients (2.4%) had events that were considered serious. A total of 35 patients (28%) were found to have intracranial hemorrhage on 24-hour CT of which 14 (11.2%) were symptomatic. All cause mortality was 32.8% at 90 days with 25% of the patients achieving a modified Rankin Scale score of < or =2.
CONCLUSIONS:
These results suggest the Penumbra System allows safe and effective revascularization in patients experiencing ischemic stroke secondary to large vessel occlusive disease who present within 8 hours from symptom onset.
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.
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.
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.
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.
The Penumbra system is a newly approved mechanical device for the treatment of acute stroke designed for better and faster recanalization. We describe our initial experience with the use of this device.
We studied 27 consecutive patients with acute ischemic strokes due to arterial occlusions presenting at our center from January to October 2009. The primary outcome was the degree of recanalization measured by thrombolysis in myocardial infarction (TIMI grade 2/3) at the end of the procedure. Secondary end points were the proportion of patients who achieved a modified Rankin scale (mRS) ≤2 at 3 months, all-cause mortality and intracerebral hemorrhage (ICH) on non contrast computed tomography at 24 h. Procedural complications were also recorded.
Of 27 patients (13 male, mean age 61 years) in the study, 22 (81%) patients had anterior circulation strokes and five (18%) had posterior circulation strokes. Twenty-three (85%) patients achieved TIMI grade 2/3 recanalization at completion of the procedure. Excluding five patients who needed use of a second device, the Penumbra system achieved TIMI grade 2/3 recanalization in 67% of patients. Thirteen (48%) patients had mRS ≤2 at 3-month follow-up. Procedural and post-procedural complications included vasospasm (3.7%), distal emboli (48.1%), and ICH (33.3%). The distribution of ICH is as follows: hemorrhagic infarct type 1 (25.9%), parenchymal hemorrhage type 1 (3.7%), and parenchymal hemorrhage type 2 (3.7%). All-cause mortality was 19%.
High recanalization rates and good clinical outcomes are achievable with the Penumbra system. Complication rates are comparable to a previously published literature.
Large IC artery occlusion is often resistant to recanalization. We present our initial experience with the PS.
Presenting with a severe acute ischemic stroke, the first 27 consecutive patients were considered for thromboaspiration therapy and retrospective data base analysis. All patients received standard thrombectomy treatment as monotherapy or in combination with thrombolysis or IC stent placement. The primary end point was revascularization of the target vessel to grade 2 or 3 on the TICI scale. Secondary end points were improvement of >4 points on the NIHSS score at discharge and favorable outcome, and improvement in overall mortality at 3 months and in sICH- and procedure-related adverse events.
At baseline, the mean age was 66 +/- 14 years and the mean NIHSS score was 14 +/- 7. The anterior circulation was affected in 23 patients, and there were 4 basilar artery occlusions. Intracranial stent placement was performed in 4 patients. A recanalization to TICI 2 or 3 was achieved in 25 patients (93%). None of the patients developed sICH. At hospital discharge, 15 patients (56%) had an NIHSS improvement of >4 and 13 patients (48%) had an mRS score of <2 at 3 months. There was a significant correlation between complete vessel recanalization and favorable outcome. The all-cause mortality at 3 months was 11%.
The PS showed a high potential for recanalization of acute thromboembolic occlusions of the large cerebral arteries. Complete recanalization was strongly correlated with good clinical outcome.
Data from recent reports have indicated that mechanical thrombectomy may have potential as a treatment for acute ischemic stroke. The purpose of this study was to assess the safety and performance of the Penumbra System (PS): a novel mechanical device designed to reduce clot burden in acute stroke due to large-vessel occlusive disease.
A prospective, single arm, independently monitored and core laboratory adjudicated trial enrolled subjects with an acute neurologic deficit consistent with acute stroke, presenting within 8 hours of symptom onset and an angiographically verified occlusion (Thrombolysis in Myocardial Infarction [TIMI] grade 0 or 1) of a treatable intracranial vessel. The primary end point was revascularization of the target vessel to TIMI grade 2 or 3. Secondary end points were the proportion of subjects who achieved a modified Rankin Scale (mRS) score of 2 or less or a 4-point improvement on the National Institutes of Health Stroke Scale (NIHSS) score at 30-day follow-up, as well as all-cause mortality.
Twenty-three subjects were enrolled, and 21 target vessels were treated in 20 subjects by the PS. At baseline, mean age was 60 years, mean mRS score was 4.6, and mean NIHSS score was 21. Postprocedure, all 21 of the treated vessels (100%) were successfully revascularized by the PS to TIMI 2 or 3. At 30-day follow-up, 9 subjects (45%) had a 4-point or more NIHSS improvement or an mRS of 2 or less. The all-cause mortality rate was 45% (9 of 20), which is lower than expected in this severe stroke cohort, where 70% of the subjects at baseline had either an NIHSS score of more than 20 or a basilar occlusion.
Thus, early clinical experience suggests that the PS allows revascularization in certain subjects experiencing acute ischemic stroke.
BACKGROUND AND PURPOSE: This study examines whether anatomic extent of pial collateral formation documented on angiography during acute thromboembolic stroke predicts clinical outcome and infarct volume following intra-arterial thrombolysis, compared with other predictive factors. METHODS: Angiograms, CT scans, and clinical information were retrospectively reviewed in 65 consecutive patients who underwent thrombolysis for acute ischemic stroke. Clinical data included age, sex, time to treatment, National Institutes of Health Stroke Scale (NIHSS) score on presentation of symptoms, NIHSS score at the time of hospital discharge, and modified Rankin scale score at time of hospital discharge. Site of occlusion, scoring of anatomic extent of pial collaterals before thrombolysis, and recanalization (complete, partial, or no recanalization) were determined on angiography. Infarct volume was measured on CT scans performed 24-48 hours after treatment. RESULTS: Fifty-three patients (82%) qualified for review. Both infarct volume and discharge modified Rankin scale scores were significantly lower for patients with better pial collateral scores than those with worse pial collateral scores, regardless of whether they had complete (P < .0001) or partial (P = .0095) recanalization. Adjusting for other factors, regression analysis models indicate that the infarct volume was significantly larger (P < .0001) and modified discharge Rankin scale score and discharge NIHSS score significantly higher for patients with worse pial collateral scores. Similarly, adjusting for other factors, the infarct volume was significantly lower (P = .0006) for patients with complete recanalization than patients with partial or no recanalization. CONCLUSIONS: Evaluation of pial collateral formation before thrombolytic treatment can predict infarct volume and clinical outcome for patients with acute stroke undergoing thrombolysis independent of other predictive factors. Thrombolytic treatment appears to have a greater clinical impact in those patients with better pial collateral formation.
Collaterals sustain the penumbra before recanalization and offset infarct growth, yet the influence of baseline collateral flow on recanalization after endovascular therapy remains relatively unexplored.
We analyzed consecutive patients who received endovascular therapy for acute cerebral ischemia from 2 distinct study populations. We assessed the relationship between pretreatment collateral grade and vascular recanalization (Thrombolysis In Myocardial Ischemia [TIMI] scale). In addition, we assessed infarct growth on serial MRI.
A total of 222 patients was included, 138 from the United States and 84 from South Korea. Complete revascularization occurred in 14.1% (11 of 78) patients with poor pretreatment collateral grades, whereas it was observed in 25.2% (26 of 103) patients with good collaterals and 41.5% (17 of 41) patients with excellent collaterals (P<0.001). This relationship was consistently observed in both study populations, although the mode of endovascular therapy was different between them. After adjustment for other factors, including mode of endovascular therapy, prior use of intravenous tissue plasminogen activator, and site of occlusion, pretreatment collateral grade was independently associated with recanalization. When revascularization was achieved, greater infarct growth occurred in patients with poor collaterals than in those with good collaterals (P=0.012).
Our data indicate that angiographic collateral grade determines the recanalization rate after endovascular revascularization therapy. When therapeutic revascularization was achieved, beneficial effects were not observed in patients with poor collaterals. Angiographic collateral grade may therefore help guide treatment decision-making in acute cerebral ischemia.
The role of noninvasive methods in the evaluation of collateral circulation has yet to be defined. We hypothesized that a favorable pattern of leptomeningeal collaterals, as identified by CT angiography, correlates with improved outcomes.
Data from a prospective cohort study at 2 university-based hospitals where CT angiography was systematically performed in the acute phase of ischemic stroke were analyzed. Patients with complete occlusion of the intracranial internal carotid artery and/or the middle cerebral artery (M1 or M2 segments) were selected. The leptomeningeal collateral pattern was graded as a 3-category ordinal variable (less, equal, or greater than the unaffected contralateral hemisphere). Univariate and multivariate analyses were performed to define the independent predictors of good outcome at 6 months (modified Rankin Scale score ≤2).
One hundred ninety-six patients were selected. The mean age was 69±17 years and the median National Institute of Health Stroke Scale score was 13 (interquartile range, 6 to 17). In the univariate analysis, age, baseline National Institute of Health Stroke Scale score, prestroke modified Rankin Scale score, Alberta Stroke Programme Early CT score, admission blood glucose, history of hypertension, coronary artery disease, congestive heart failure, atrial fibrillation, site of occlusion, and collateral pattern were predictors of outcome. In the multivariate analysis, age (OR, 0.95; 95% CI, 0.93 to 0.98; P=0.001), baseline National Institute of Health Stroke Scale (OR, 0.75; 0.69 to 0.83; P<0.001), prestroke modified Rankin Scale score (OR, 0.41; 0.22 to 0.76; P=0.01), intravenous recombinant tissue plasminogen activator (OR, 4.92; 1.83 to 13.25; P=0.01), diabetes (OR, 0.31; 0.01 to 0.98; P=0.046), and leptomeningeal collaterals (OR, 1.93; 1.06 to 3.34; P=0.03) were identified as independent predictors of good outcome.
Consistent with angiographic studies, leptomeningeal collaterals on CT angiography are also a reliable marker of good outcome in ischemic stroke.
This is the first single center experience illustrating the effectiveness of the penumbra system (PS) in the treatment of large vessel occlusive disease in the arena of acute ischaemic stroke. The PS is an innovative mechanical thrombectomy device, employed in the revascularization of large cerebral vessel occlusions in patients via the utilization of an aspiration platform.
This is a prospective, non-randomized controlled trial evaluating the clinical and functional outcome in 29 patients with acute intra-cranial occlusions consequent to mechanical thrombectomy by the PS either as mono-therapy or as an adjunct to current standard of care. Patients were evaluated by a neurologist and treated by our in house interventional neuro-radiologists. Primary end-points were revascularization of the occluded target vessel to TIMI grade 2 or 3 and neurological outcome as measured by an improvement in the NIH Stroke Scale (NIHSS) score after the procedure.
Complete revascularization (TIMI 3) was achieved in 21/29 (72.4%) of patients. Partial revascularization (TIMI 2) was established in 4/29 (13.8%) of patients. Revascularization failed in four (13.8%) patients. Nineteen (19) patients (65.5%) had at least a four-point improvement in NIHSS scores. Modified Rankin scale scores of < or =2 were seen in 37.9% of patients. There were no device-related adverse events. Symptomatic intra-cranial hemorrhage occurred in 7% of patients.
The PS has the potential of exercising a significant impact in the interventional treatment of ischaemic stroke in the future.
Revascularization therapies for acute stroke patients aim to rescue the ischemic penumbra by restoring the patency of the occluded artery ("recanalization") and the downstream capillary blood flow ("reperfusion"). This article reviews the definition of recanalization and reperfusion used in stroke clinical trials and their limitations and proposes a study design to determine the relative importance of recanalization, reperfusion, and collateral flow in evaluating the efficacy of revascularization therapies for acute ischemic stroke.
Intravenous administration of 80 mg of recombinant tissue plasminogen activator (rt-PA, 40, 20, and 20 mg in successive hours) and streptokinase (SK, 1.5 million units over 1 hr) was compared in a double-blind, randomized trial in 290 patients with evolving acute myocardial infarction. These patients entered the trial within 7 hr of the onset of symptoms and underwent baseline coronary arteriography before thrombolytic therapy was instituted. Ninety minutes after the start of thrombolytic therapy, occluded infarct-related arteries had opened in 62% of 113 patients in the rt-PA and 31% of 119 patients in the SK group (p less than .001). Twice as many occluded infarct-related arteries opened after rt-PA compared with SK at the time of each of seven angiograms obtained during the first 90 min after commencing thrombolytic therapy. Regardless of the time from onset of symptoms to treatment, more arteries were opened after rt-PA than SK. The reduction in circulating fibrinogen and plasminogen and the increase in circulating fibrin split products at 3 and 24 hr were significantly less in patients treated with rt-PA than in those treated with SK (p less than .001). The occurrence of bleeding events, administration of blood transfusions, and reocclusion of the infarct-related artery was comparable in the two groups. Thus, in patients with acute myocardial infarction, rt-PA elicited reperfusion in twice as many occluded infarct-related arteries as compared with SK at each of seven serial observations during the first 90 min after onset of treatment.
Early reperfusion is a predictor of good outcome in acute ischemic stroke. We investigated whether middle cerebral artery (MCA) occlusions have a better clinical outcome and proportion of recanalization compared with internal carotid artery (ICA) occlusion after standard treatment with intravenous (IV) tissue plasminogen activator (tPA).
In a retrospective analysis of our prospective stroke database between January 7, 1998, and January 30, 2002, we identified 36 consecutive patients who were treated with IV tPA within 3 hours after symptom onset of a stroke in the distribution of a documented ICA or MCA occlusion. The National Institutes of Health Stroke Scale (NIHSS) score was recorded before tPA, at 24 hours, 3 days, and 3 months after stroke. Three-month outcome was recorded by modified Rankin scale. Magnetic resonance angiography or computed tomographic angiography was obtained before tPA. The presence of recanalization was assessed by transcranial Doppler and/or magnetic resonance angiography within 3 days after stroke onset.
Nineteen patients had MCA occlusion, and 17 had ICA-plus-MCA occlusion before tPA. Although there was no difference in age and NIHSS at day 0 between the 2 groups, the MCA group had a lower day 3 NIHSS score compared with the ICA group (P=0.006) in an ANCOVA. In addition, patients who had a MCA occlusion had lower day 1 and 3 NIHSS scores compared with the ICA group (P=0.04 and P=0.03, respectively; Wilcoxon rank sum). Similarly, NIHSS was significantly lower in patients who recanalized on days 1 and 3 (P=0.004 and P=0.003 respectively, Wilcoxon rank sum). When we adjusted for NIHSS score at day 0 in an ANCOVA, the adjusted mean was lower in the group that recanalized compared with the group that did not recanalize (P<0.001). There was a significant difference between the proportion of recanalization in the MCA group (15 of 17 recanalized, 88%) at 3 days after tPA compared with that of the ICA group (5 of 16 recanalized, 31%; P=0.001, Fisher exact test). The 3-month modified Rankin scale was not different between the 2 groups.
Despite comparable age and NIHSS scores before IV tPA, MCA occlusions have lower day 1 and 3 NIHSS scores and higher proportion of recanalization compared with ICA occlusions. A combined IV/intra-arterial or mechanical thrombolysis may be needed to achieve early recanalization in ICA occlusions.