Thrombectomy Technique Research Articles

Comparative analysis of endovascular methods for treatment of acute lower limb ischemia

Acute lower limb ischemia (ALLI) is defined as a sudden decrease in lower limb arterial perfusion, which lasts less than 14 days and threatens a limb viability. This condition is one of the most common emergencies in vascular surgery, requiring immediate diagnosis and treatment, because untimely revascularization of lower limb leads to high amputation rate and mortality in postoperative period.
 Currently there exist many methods of lower limb revascularization, however, in fact, they all can be divided into two large groups: open, surgical, and endovascular treatment. The choice between them depends on many factors. Since introduction of Fogarty catheter, balloon thromboembolectomy became a «gold standard» in treatment for ALLI. Nevertheless, at the same time endovascular methods appeared, the first one being catheter-based thrombolysis (CBT). Since its appearance, CBT gradually improved with deeper understanding of indications for its use, improvement of the technique of intervention, appearance of different thrombolytic agents and instruments. Nowadays a number of international guidelines determine CBT as a first line treatment of most patients with ALLI.
 Endovascular thrombectomy techniques appeared in the 90s of XX century as an attempt tocombine advantages of open surgery (rapid and, in ideal conditions, complete restoration of limb perfusion) and of endovascular intervention (minimal invasiveness). They include manual aspiration, rheolytic (hydrodynamic), rotational, aspiration thrombectomy and pharmacomechanical thrombolysis. According to numerous studies, these techniques demonstrate quite impressive results and, probably, in the near future one of them can become a new «gold standard» in treatment for ALLI.

Overview of Mechanical Thrombectomy Techniques.

The recently reported superiority of mechanical thrombectomy to intravenous thrombolytics has jettisoned endovascular intervention into the forefront of acute ischemic stroke (AIS) management. These successes have allowed a chance for recanalization for patients not meeting the strict eligibility criteria for intravenous thrombolytics. Stent retrieval and aspiration have emerged as two of the most popular and effective approaches for AIS thrombectomy. Since the beginning of mechanical thrombectomy with the Merci device (Stryker) and first-generation Penumbra aspiration system (Penumbra Inc), contemporary techniques have demonstrated reliable recanalization and improved clinical outcomes. Here, we review the use of stent retrieval and aspiration, as well as their synergy, in the management of AIS.

Mechanical thrombeсtomy and trombaspiration in stroke. Problem claims

Objective — to evaluate the effectiveness of endovascular mechanical recanalization methods in ischemic stroke and the analysis of problem cases.Materials and methods. A retrospective analysis of the results of treatment of 33 patients with acute ischemic stroke due to occlusion of a large vessel was performed. There were 18 (54.5 %) men and 15 (45.5 %) women. Endovascular interventions were performed in all patients to restore cerebral arteries patency using various methods and techniques of mechanical thrombectomy. All patients underwent neuroimaging (CT of the brain and selective cerebral subtraction angiography). A topographical assessment of early CT-changes in ischemic stroke was performed using the ASPECTS scale. The severity of neurological symptoms in the acute period of ischemic stroke was assessed according to the NIHSS score. The severity of the condition – on the NIHSS score. The mTICI scale was used to assess the success of recanalization (reperfusion) after mechanical thrombectomy.Results. Successful recanalization (mTICI 2b-3) with the use of stent retrievers and distal aspiration catheters was achieved in 22 (66.7 %) cases. The total number of intraoperative complications was 12.0 %. Mortality rate – 12.0 %.Conclusions. Endovascular reperfusion methods using stent retrievers and distal aspiration catheters for acute ischemic stroke are effective. Endovascular reperfusion advisable to start with a mechanical thrombus aspiration. When performing endovascular recanalization, the use of stent retrievers in combination with guide balloon catheters only without distal aspiration catheters increases the risk of distal reembolism and embolism of other arterial basins.

Noteworthy Cardiac Surgical Literature 2018: Value-Based Bundled Payments, Opioid Crisis and Cardiac Surgery, Percutaneous Suction Thrombectomy for Intracardiac/Caval Thrombus and Vegetations, and Minimally Invasive Left Ventricular Assist Device Placement.

There has been tremendous evolution in the care of cardiac surgical patients in 2018. In this article, 4 topics of considerable impact on cardiac surgical care in the current landscape are reviewed based on recent publications. The first topic reviews the recent paradigm shift to value-based payments and the potential role of bundled payments on health care and physician reimbursement. The second topic highlights the impact of the opioid crisis on cardiac surgery. The third topic demonstrates the increasing utilization and expanding role of novel percutaneous suction thrombectomy technique in the extraction of caval and right-sided intracardiac thrombi and vegetations with veno-venous bypass. The final topic reviews the current trend of minimally invasive left ventricular assist device placement. Each of these topics addresses the contemporary issues in cardiac surgery with the reasoning for evolution in our current practices in 2018.

TCTAP C-033 "Mother-in-child" Thrombectomy Technique in a Young Man with Acute Myocardial Infarction and Large Thrombus Burden Undergoing Percutaneous Coronary Intervention

### Patient Initials or Identifier Number NND ### Relevant Clinical History and Physical Exam Male, 31-year-old, hospitalization with typical angina 4 hours before. History: smoking 20 cigarettes per day for 10 years use marijuana 1 week recently Examine: Glasgow 15 points heart rate 90 bpm

Front-line thrombectomy for acute large-vessel occlusion with underlying severe intracranial stenosis: stent retriever versus contact aspiration.

The optimal front-line thrombectomy choice for primary recanalization of a target artery remains unknown for patients with acute large-vessel occlusion (LVO) and an underlying intracranial atherosclerotic stenosis (ICAS). The authors aimed to compare procedural characteristics and outcomes between patients who received a stent-retriever thrombectomy (SRT) and patients who received a contact aspiration thrombectomy (CAT), as the front-line approach for treating LVO due to severe underlying ICAS. One hundred thirty patients who presented with acute LVO and underlying severe ICAS at the occlusion site were included. Procedural characteristics and treatment outcomes were compared between patients treated with front-line SRT (n = 70) and those treated with front-line CAT (n = 60). The primary outcomes were the rate of switching to an alternative thrombectomy technique, time from groin puncture to initial reperfusion, and duration of the procedure. Initial reperfusion was defined as revealing the underlying culprit stenosis with an antegrade flow after thrombectomy. The rate of switching to an alternative thrombectomy after failure of the front-line technique was significantly higher in the CAT group than in the SRT group (40% vs 4.3%; OR 2.543, 95% CI 1.893-3.417, p < 0.001). The median time from puncture to initial reperfusion (17 vs 31 minutes, p < 0.001) and procedure duration (39 vs 75.5 minutes, p < 0.001) were significantly shorter in the SRT group than in the CAT group. In the binary logistic regression analysis, a longer time from puncture to initial reperfusion was an independent predictor of a 90-day poor (modified Rankin Scale score 3-6) functional outcome (per 1-minute increase; OR 1.029, 95% CI 1.008-1.050, p = 0.006). The authors' results suggest that SRT may be more effective than CAT for identifying underlying culprit stenosis and therefore considered the optimal front-line thrombectomy technique in acute stroke patients with LVO and severe underlying ICAS.

Foley catheter-assisted six-step thrombectomy technique in the surgical management of renal cell carcinoma with Mayo level II to IV tumor thrombus.

ObjectiveTo simplify Foley catheter-assisted thrombectomy to a six-step approach and determine the feasibility and results of this technique for renal cell carcinoma (RCC) with a Mayo level II to IV tumor thrombus (TT).MethodsThe surgical records of patients with RCC with a Mayo level II to IV TT treated in our hospital were retrospectively reviewed. Fifteen patients who underwent radical nephrectomy and thrombectomy with a Foley catheter-assisted procedure were included. Epidemiological and clinicopathological features, operation-related variables, and outcomes were evaluated.ResultsThe TTs in all 15 patients were successfully retracted by the Foley catheter. The mean operation time was 420.1 ± 108.9 minutes. The mean intraoperative blood loss and perioperative red blood cell transfusion volumes were 1846.7 ± 1467.8 and 1288.7 ± 1060.6 mL, respectively. Five patients had perioperative complications. The median follow-up time was 9 (range, 0–34) months, and four patients died of the disease.ConclusionsSimplification of Foley catheter-assisted thrombectomy to a six-step approach results in the probability of avoiding thoracotomy or cardiopulmonary bypass to a certain degree and is associated with fewer complications, less blood loss, and less perioperative red blood cell transfusion. However, experienced surgeons and multidisciplinary cooperation are still needed.

03:09 PM Abstract No. 161 6-French/088 distal guide sheath access into the petrocavernous internal carotid artery to optimize mechanical thrombectomy

Modern stent retriever-based thrombectomy techniques for emergent large vessel occlusions contributed to the successful clinical trials on endovascular acute ischemic stroke intervention. Various adjunctive techniques have been described including the use of a balloon guide catheter (BGC) and/or distal access catheter (DAC) aspiration to improve first pass recanalization, complete reperfusion, and clinical outcomes. We describe a novel technique using a flexible 6French/088 distal guide sheath (DGS), defined as advancement into the petrocavernous internal carotid artery (ICA), to limit antegrade flow without a BGC and reduce the distance/tortuosity for clot extraction. We studied the relative safety and efficacy of DGS placement during standard stent retriever with DAC aspiration thrombectomy A retrospective review of 85 consecutive patients with intracranial ICA or M1-M2 middle cerebral artery (MCA) occlusions underwent stent retriever with DAC aspiration thrombectomy over a 30-month period. Patients were divided based on thrombectomy techniques, conventional stent retriever with DAC aspiration group (traditional group) and using an adjunctive DGS technique (target group). We compared recanalization efficiency (procedure time and passes), reperfusion efficacy using the modified Thrombolysis in Cerebral Ischemia (mTICI) scale, and clinical outcomes of functional independence at 90 days (modified Rankin score 0-2). We identified 36 patients (median age 69 years with NIHSS 18) in the target group and 49 patients (median age 73 years with NIHSS 20) in the traditional group (p=0.11 and 0.12 respectively). There was a trend towards lower groin to revascularization time (53 minutes vs 61 minutes) and lower mean number of thrombectomy attempts in the target group (2.2 vs 2.6), yet those trends did not reach statistical significance. The target group offered higher rates of TICI ≥2 b reperfusion (97% vs 84%; P-value 0.046) that corresponded with increased functional independence at 90 days (65% vs 38%; P=0.03). Optimizing mechanical thrombectomy techniques by advancing a DGS into the petro-cavernous ICA may confer higher reperfusion rates and improved clinical outcomes.

Abstract WMP70: Etiology of Stroke Based on Early Analysis of Clot Cytometry Obtained Through First Pass Technique for Mechanical Thrombectomy

Introduction: Mechanical thrombectomy is the best treatment for large vessel occlusion in acute strokes, this technique can obtain clots for further analysis. Objective: To evaluate flow cytometry in thrombi obtained in the treatment of hyperacute stroke by mechanical thrombectomy, as a diagnostic tool in the etiological study of stroke Methods: Consecutively, intracranial clots were obtained in the hyperacute phase of stroke with solitaire device. Cell suspensions of thrombi were prepared that were labeled by direct immunofluorescence using conjugated monoclonal antibodies. The labeled samples were acquired in a Naviostm flow cytometer (Beckman-Coulter). The following leukocyte populations were studied: granulocytes, monocytes, total lymphocytes, T lymphocytes (CD3 +), helper T lymphocytes (CD3 +, CD4 +), suppressor-cytotoxic T lymphocytes (CD3 +, CD8 +), TNK lymphocytes (CD3 +, CD56 / 16 +) , NK lymphocytes (CD3-, CD56 / 16 +) and B lymphocytes (CD19 +). The results were expressed as percentages (%). The aetiology of stroke was categorized in secondary to: major structural heart disease, atrial fibrillation, stroke of atherosclerotic etiology (severe stenosis or complicated aortic atheromatosis ulceration) or infrequent causes. Results: 40 samples were analyzed. Clots of atherosclerotic etiology (n = 13) were associated with higher% of CD4 T lymphocytes (24.85% vs 15.83% p = 0.016), and higher% of NK (21.08% vs 17.04) % p = 0.07), also showed a tendency to a higher% LT (23.69% vs 16.46% p = 0.052). Strokes secondary to AF were associated with a higher percentage of CD8 T lymphocytes (20.24 vs 13.56 p = 0.048). Conclussion: Analysis by flow cytometry of clots obtained in the hyperacute phase of stroke showed significant differences in the different lymphocyte populations according to the etiology

The Aspirations of Direct Aspiration for Thrombectomy in Ischemic Stroke: A Critical Analysis.

The treatment of acute ischemic stroke by mechanical thrombectomy has been revolutionary, however most of the clinical trials were done with the use a stent retriever. At the same time, an alternative technique of thrombectomy through direct aspiration with a large bore distal access catheter at the face of the clot is rapidly gaining popularity. Nonetheless, the data supporting this new technique is not yet as mature as that available on stent retrievers. This review is a critical analysis of the evidence supporting the principle of direct aspiration thrombectomy and a discussion of its potential strengths and weaknesses in comparison to the available studies on stent retrievers. While this is by no means a conclusive review, it should serve as a yardstick of where the science is currently, and what are the next trials that are necessary.

Comparing Thrombectomy Techniques: Combination Use of Stent–retriever and Aspiration Catheter vs. Conventional Use of Stent–retriever

Comparing Thrombectomy Techniques: Combination Use of Stent–retriever and Aspiration Catheter vs. Conventional Use of Stent–retriever

A Retrospective Single-Center Case Series of Direct Aspiration Thrombectomy as First-Line Approach in Ischemic Stroke and Review of the Literature

Introduction: The benefit of the direct aspiration thrombectomy (ADAPT) technique for the treatment of ischemic stroke due to large vessel occlusion are challenged after publishing of the ASTER trial that failed to show superiority of ADAPT compared to stent retriever. Aim of the present single-center study was a retrospective evaluation of the ADAPT technique comparing our results with literature. Material/methods: We retrospectively analyzed institutional data of stroke procedures in patients with mainstem occlusion of the middle cerebral artery treated between November 2016 and December 2017 with an initial attempt of manual thrombaspiration. Reperfusion rate (thrombolysis in cerebral infarction), procedural times, early clinical outcome and complications were recorded. Results: Forty patients were treated by using direct thrombaspiration in middle cerebral artery mainstem occlusion. Median age was 67.5 (±17.8) years (m = 27.5%). Median Baseline National Institutes of Health Stroke Scale score was 12 (IQR 7) preintervention and 3 (IQR 11) postintervention. Twenty-eight (70%) patients received intravenous thrombolysis. Successful recanalization (modified thrombolysis in cerebral infarction ≥ 2b) could be achieved in 85% with direct aspiration alone. Mean time from groin puncture to recanalization was 25.2 ± 14.3 minutes. Embolization to new territories occurred in 1 of 40 (2.5%) cases and symptomatic intracranial hemorrhage in 3 of 40 (7.5%). Nineteen of 40 (47.5%) patients achieved favorable outcome (modified Rankin scale 0-2) at discharge. Conclusions: The ADAPT technique presented as a safe and efficient first-line recanalization strategy with good clinical outcome for treatment of acute ischemic stroke resulting from large vessel occlusions in this single-center study and review of the literature. However, the concept of ADAPT as an equivalent first-line approach to stent retriever thrombectomy has to be proven by future randomized studies.

Acute Ischemic Stroke: A Review of Imaging, Patient Selection, and Management in the Endovascular Era. Part I: Initial Management and Imaging

AbstractTill recently, the mainstay of management of acute ischemic stroke (AIS) has been intravenous thrombolysis. However, response to treatment and outcomes in the presence of a large vessel occlusion (LVO) were largely suboptimal. Endovascular thrombectomy techniques with stentrievers and aspiration catheters have revolutionized stroke treatment significantly, improving outcomes in this once untreatable disease. The interventional radiologist must play an active role in the stroke team in streamlining imaging as well as endovascular management. The focus of this review article is on initial management and imaging. Initial measures consist of patient resuscitation, basic investigations and assessment of stroke severity using the National Institutes of Health Stroke Scale (NIHSS), all of which have therapeutic and prognostic implications to be considered by the neurointerventionist. Imaging must aim to be swift and efficient. Choice of a modality must be based on available infrastructure as well as clinical-radiologic factors such as the time since ictus or posterior circulation involvement. Computed tomography (CT) is the preferred modality for its speed, whereas magnetic resonance imaging (MRI) remains the gold standard problem solving technique for detection of stroke. Exclusion of hemorrhagic stroke and other stroke mimics is the first objective. Thereafter, imaging is targeted toward assessing the parenchyma and vasculature. Defining the core and penumbra is the most important goal of parenchymal imaging. The core may be defined by the presence of early ischemic changes on CT, CT angiographic source images, or diffusion restriction on MRI. The penumbra is approximated by collateral status or perfusion methods. The prime directive of vascular imaging, either CT or magnetic resonance angiography (MRA) is to establish the presence of an LVO. Once confirmed, the decision for thrombolysis and/or thrombectomy is based on clinical and imaging criteria, the most ideal being that of a moderately severe stroke with a small core and LVO on imaging.

Acute Ischemic Stroke: A Review of Imaging, Patient Selection, and Management in the Endovascular Era. Part II: Patient Selection, Endovascular Thrombectomy, and Postprocedure Management

AbstractAppropriate patient selection and expedient recanalization are the mainstay of modern management of acute ischemic stroke (AIS). Only a minority of patients (7–15%) of patients are eligible for endovascular therapy. Patient selection may be time based or perfusion based. Central to both paradigms is the selection of a patient with a small core, a significant penumbra that can be differentiated from areas of oligemia. A brief review of patient selection methods is presented. Endovascular thrombectomy techniques using stentrievers or aspiration catheters have now become the treatment of choice for AIS with large vessel occlusion. A range of devices, each with its own advantages and disadvantages, are available in the market for the neurointerventionist to choose. Techniques vary between devices and between operators, but standardization and protocolization are important within each center. Complications must be anticipated to be avoided. Once reperfusion is achieved, outcomes must be safeguarded with competent postprocedure management to prevent secondary brain injury. These aspects are reviewed in this article.

Outcomes of endovascular thrombectomy in the elderly: a ‘real-world’ multicenter study

BackgroundThe efficacy of endovascular thrombectomy (ET) for acute ischemic stroke (AIS) in octogenarians is still controversial.ObjectiveTo evaluate, using a large multicenter cohort of patients, outcomes after ET in octogenarians compared...

Outcomes of Stent Retriever versus Aspiration-First Thrombectomy in Ischemic Stroke: A Systematic Review and Meta-Analysis.

There is ongoing debate regarding the optimal first-line thrombectomy technique for large-vessel occlusion. We performed a systematic review and meta-analysis of comparative studies on stent retriever-first and aspiration-first thrombectomy. We searched Ovid MEDLINE, PubMed, and EMBASE from 2009 to February 2018. Two reviewers independently selected the studies. The primary end point was successful reperfusion (TICI 2b/3). Random-effects meta-analysis was used for analysis. Eighteen studies including 2893 patients were included. There was no significant difference in the rate of final successful reperfusion (83.9% versus 83.3%; OR = 0.87; 95% CI, 0.62%-1.27%) or good functional outcome (mRS 0-2) at 90 days (OR = 1.07; 95% CI, 0.80-1.44) between the stent-retriever thrombectomy and aspiration groups. The stent-retriever thrombectomy-first group achieved a statistically significant higher TICI 2b/3 rate after the first-line device than the aspiration-first group (74.9% versus 66.4%; OR = 1.53; 95% CI, 1.14%-2.05%) and resulted in lower use of a rescue device (19.9% versus 32.5%; OR = 0.36; 95% CI, 0.14%-0.90%). The aspiration-first approach resulted in a statistically shorter groin-to-reperfusion time (weighted mean difference, 7.15 minutes; 95% CI, 1.63-12.67 minutes). There was no difference in the number of passes, symptomatic intracerebral hemorrhage, vessel dissection or perforation, and mortality between groups. Most of the included studies were nonrandomized. There was significant heterogeneity in some of the outcome variables. Stent-retriever thrombectomy-first and aspiration-first thrombectomy were associated with comparable final reperfusion rates and functional outcome. Stent-retriever thrombectomy was superior in achieving reperfusion as a stand-alone first-line technique, with lower use of rescue devices but a longer groin-to-reperfusion time.

First-Line A Direct Aspiration First-Pass Technique vs. First-Line Stent Retriever for Acute Ischemic Stroke Therapy: A Meta-Analysis.

Background: Recent trials have proved the efficacy of mechanical thrombectomy over medical treatment for patients with acute ischemic stroke, with the balance of equivalent rates of adverse events. Stent retrievers were applied predominantly in most trials; however, the role of other thrombectomy devices has not been well validated. A direct aspiration first-pass technique (ADAPT) is proposed to be a faster thrombectomy technique than the stent retriever technique. This meta-analysis investigated and compared the efficacy and adverse events of first-line ADAPT with those of first-line stent retrievers in patients with acute ischemic stroke.Methods: A structured search was conducted comprehensively. A total of 1623 papers were found, and 4 articles were included in our meta-analysis. The Critical Appraisal Skills Programme tools were applied to evaluate the quality of studies. The primary outcome was defined as the proportion of patients with the Thrombolysis in Cerebral Ischemia (TICI) scale of 2b/3 at the end of all procedures. Secondary outcomes were the proportion of patients with functional independence (modified Rankin scale of 0–2) at the third month, the proportion of patients with the Thrombolysis in Cerebral Ischemia (TICI) scale of 2b/3 by primary chosen device, and the proportion of patients who received rescue therapies. Safety outcomes were the symptomatic intracranial hemorrhage (sICH) rate and the mortality rate within 3 months.Results: One randomized controlled trial, one prospective cohort study, and two retrospective cohort studies were included. No significant difference between these 2 strategies of management were observed in the primary outcome (TICI scale at the end of all procedures, odds ratio [OR] = 0.78), two secondary outcomes (functional independence at the third month, OR = 1.16; TICI scale by primary chosen device, OR = 1.25), and all safety outcomes (sICH rate, OR = 1.56; mortality rate, OR = 0.91). The proportion of patients who received rescue therapies was higher in the first-line ADAPT group (OR = 0.64).Conclusions: Among first-line thrombectomy devices for patients with ischemic stroke, ADAPT with the latest thrombosuction system was as efficient and safe as stent retrievers.

Endovascular Therapy Strategy for Acute Embolic Tandem Occlusion: The Pass-Thrombectomy-Protective Thrombectomy (Double PT) Technique

Embolic occlusions of the common carotid artery (CCA)/internal carotid artery (ICA) and intracranial artery occlusions in acute ischemic stroke are associated with high morbidity and can benefit from endovascular therapy. However, the optimal endovascular strategy for these conditions is unclear. This study aimed to evaluate the feasibility of the pass-thrombectomy-protective thrombectomy (double PT) technique and the clinical outcome of treated patients. We collected data on embolic occlusion of the CCA/ICA and intracranial artery occlusion in our prospective stroke registry database between January 2015 and February 2017. Clinical and angiographic data were retrospectively analyzed. Clinical outcome was evaluated at 3 months (modified Rankin scale [mRS] score), and an mRS score of 2 or lower was defined as a good clinical outcome. A total of 7 patients with tandem occlusion were included, with a mean age of 66 years. The median admission National Institutes of Health Stroke Scale score was 20, and 6 of 7 patients (85.7%) underwent successful recanalization. The median reperfusion time of the affected intracranial artery was 61 minutes. The rate of good clinical outcome was 42.9% (3/7), the mortality rate was 14.3% (1/7), and the embolic event rate was 14.3% (1/7) when the proximal clot was retrieved. The double PT technique is feasible and safe in treating initial embolic tandem occlusion of the CCA/ICA.

Combined aspiration thrombectomy and continuous intrasinus thrombolysis for cerebral venous sinus thrombosis: technical note and case series.

Cerebral venous sinus thrombosis is an uncommon cause of stroke with high morbidity and mortality rates from venous infarction, intracranial hemorrhage, and extensive cerebral edema. Endovascular treatment with various devices has been proposed as a salvage treatment when standard medical treatment with systemic anticoagulation is ineffective, especially in long segment dural sinus thrombosis. We describe our technique of transvenous endovascular aspiration thrombectomy with large bore thrombectomy catheters, followed by placement of microcatheter for local thrombolytic infusion at the site of thrombosis. We report a retrospective study of angiographic and clinical outcome of six consecutive patients treated with this approach. Endovascular aspiration thrombectomy with large bore catheters followed by continuous local thrombolytic infusion appeared to be a safe and effective salvage treatment for selected patients with cerebral dural venous sinus thrombosis refractory to medical treatment.

Larger ACE 68 aspiration catheter increases first-pass efficacy of ADAPT technique

PurposeTo report the efficacy of A Direct Aspiration first-Pass Thrombectomy (ADAPT) technique with larger-bore ACE aspiration catheters as first-line treatment for anterior circulation emergent large vessel occlusions (ELVOs), and assess...