Randomized Trial of Intraarterial Infusion of Urokinase Within 6 Hours of Middle Cerebral Artery Stroke

Endovascular and neurosurgical management of acute ischemic stroke

Acute ischemic stroke is recognized as the third leading cause of death in the United States; improved treatments for management are important to reduce disability and death. The standard of care of acute stroke therapy has been reperfusion/recanalization of the occluded vessels using pharmacologic management, endovascular management, or a combination approach. Significant improvements have been made in the management with the use of endovascular therapy. This article reviews the literature on the endovascular and neurosurgical management of patients presenting with acute ischemic stroke and presents current evidence-based guidelines for endovascular or neurosurgical interventions outlined for management of ischemic stroke.

Guidelines for acute ischemic stroke treatment: part II: stroke treatment

The second part of these Guidelines covers the topics of antiplatelet, anticoagulant, and statin therapy in acute ischemic stroke, reperfusion therapy, and classification of Stroke Centers. Information on the classes and levels of evidence used in this guideline is provided in Part I. A translated version of the Guidelines is available from the Brazilian Stroke Society website (www.sbdcv.com.br).

Treatment of acute ischemic stroke with clot retrieval devices

OPINION STATEMENT

Mechanical clot retrieval is increasingly used for flow-restoration and thrombectomy in acute embolic stroke. Emerging as a treatment option in addition to intravenous or intra-arterial thrombolysis, it is currently being further developed and investigated as a potential first-line and stand-alone treatment. The ability to rapidly restore flow and effectively retrieve clots from large intracranial arteries is reflected by angiographic data and preliminary clinical results. This article reviews the principles and technical aspects of this new technique, its emergence from the spectrum of intravenous and endovascular stroke treatment, and summarizes the first clinical results for acute ischemic anterior and posterior circulation stroke. Clot retrieval devices are a very promising option for treatment of acute ischemic stroke in the setting of large vessel occlusion. However, there currently exists a reported discrepancy between excellent recanalization rates and less satisfactory clinical outcomes. This problem urgently needs to be addressed in a prospective randomized fashion and improvements of treatment be recognized and implemented before clot retrieval can be considered an established form of acute stroke treatment.

Developing practice recommendations for endovascular revascularization for acute ischemic stroke

Guidelines have been established for the management of acute ischemic stroke; however, specific recommendations for endovascular revascularization therapy are lacking. Burgeoning investigation of endovascular revascularization therapies for acute ischemic stroke, rapid device development, and a diverse training background of the providers performing the procedures underscore the need for practice recommendations. This review provides a concise summary of the Society of Vascular and Interventional Neurology endovascular acute ischemic stroke roundtable meeting. This document was developed to review current clinical efficacy of pharmacologic and mechanical revascularization therapy, selection criteria, periprocedure management, and endovascular time metrics and to highlight current practice patterns. It therefore provides an outline for the future development of multisociety guidelines and recommendations to improve patient selection, procedural management, and organizational strategies for revascularization therapies in acute ischemic stroke.

Evidence-based changes in devices and methods of endovascular recanalization therapy

The devices and methods of endovascular recanalization therapy (ERT) have been rapidly developed and changed since PROACT II trial. Emerging as a treatment option in addition to intravenous or intra-arterial thrombolysis, mechanical thrombectomy is currently being further developed and investigated as a potential first-line and stand-alone treatment. This review highlights and summarizes the recent clinical series and trials of the available devices and methods of ERT focusing on the multimodal approach.

Endovascular treatment of acute ischemic stroke: current indications

Endovascular stroke therapy is an effective means of achieving reperfusion in stroke patients with proximal cerebral artery occlusions. However, current guideline recommendations express uncertainty regarding the clinical efficacy of catheter-based treatments, given the lack of supportive trial data. A critical problem is that it remains unclear which patients will benefit from endovascular therapy. As such, patient selection is likely highly variable in clinical practice. This article will review the existing data to discuss the clinical and imaging factors that are relevant to patient outcomes, and which may be used to guide endovascular treatment decisions. Anterior circulation strokes represent the primary focus of this review.

Endovascular therapy yields significantly superior outcomes for large vessel occlusions compared with intravenous thrombolysis: is it time to randomize?

BACKGROUND AND PURPOSE

We compared outcomes between endovascular (EV) therapy and intravenous (IV) thrombolysis in large vessel strokes.

METHODS

223 patients who had received either IV (n=100) or EV (n=123) therapy were analyzed. Only patients with strokes involving the internal carotid artery terminus (ICA-T, n=45), the middle cerebral artery (M1, n=107) or the bifurcation branches (M2, n=71) were included. The primary endpoint was 3 month outcome based on the modified Rankin Scale (mRS) score, good-outcome defined as mRS ≤2.

RESULTS

The good outcome was 44.7% in the EV group and 26% in the IV group (p=0.003, OR 2.3, 95% CI 1.3 to 4.1). There was no difference in mortality or hemorrhage. For ICA-T occlusions, the good outcome was 27.6% in the EV and 0% in the IV group (p=0.004); for M1 occlusions, 40.6% in the EV versus 10.5% in the IV group (p=0.0006, OR 5.8, 95% CI 1.9 to 18.2); and for M2 occlusions, 76% in the EV versus 47.8% in the IV group (p=0.01, OR 3.5, 95% CI 1.2 to 10.2). For M1 occlusions, the death rate was 27.5% for the EV compared with 57.9% for the IV group (p=0.002, OR 3.6, 95% CI 1.6 to 8.3) with no difference observed in mortality for ICA-T or M2 occlusions. In the univariate analysis, age, National Institutes of Health Stroke Scale score and occlusion site were significant predictors of outcome and mortality (p<0.0001 for all). In the multivariable analysis, EV therapy (p=0.0004, OR 3.9, 95% CI 1.8 to 9) and younger age (p<0.0001, OR 0.96, 95% CI 0.9 to 0.98) were significant independent predictors of good outcome.

CONCLUSIONS

There are significantly higher odds of a favorable outcome with EV compared with IV therapy for large vessel strokes. The data support the rationale of a randomized trial for large vessel occlusions.

Efficacy and limitations of multimodal endovascular revascularization other than clot retrieval for acute stroke caused by large-vessel occlusion

BACKGROUND

The purpose of this study was to evaluate the efficacy of multimodal endovascular treatment (EVT) other than clot retrieval for acute large-vessel occlusion (LVO).

METHODS

Fifty-six consecutive patients with a median National Institutes of Health Stroke Scale (NIHSS) score of 15 were included this study. In all cases, intravenous administration of recombinant tissue plasminogen activator had failed (n = 23) or was contraindicated (n = 33). The modes of EVT performed included intra-arterial thrombolysis, mechanical clot disruption including balloon angioplasty, and stent placement. We retrospectively analyzed the treatment efficacy of these techniques and patient outcome.

RESULTS

Successful reperfusion (Thrombolysis in Cerebral Infarction grade 2B or 3) was achieved in 40 of 56 patients (71.4%), and 26 of 56 patients (46.4%) had a favorable clinical outcome (modified Rankin Scale [mRS] score 0 to 2 at 90 days). Successful reperfusion (odds ratio [OR] 163; P = .003), age (OR 0.83; P = .007), and baseline NIHSS score (OR 0.71; P = .009) were independently associated with favorable clinical outcome by multivariate analysis. Successful reperfusion rates of internal carotid terminus or M1 proximal occlusions were significantly lower than those of other vessel occlusion (47.6% v 85.7%; P = .005). Clinically significant procedure-related complications occurred in 1.8% (1/56), and symptomatic intracerebral hemorrhage (sICH) within 48 hours after EVT was observed in 5.4% (3/56) of patients.

CONCLUSIONS

Multimodal EVT for acute LVO yields a high reperfusion rate with a minimal risk of sICH and contributes to favorable patient outcomes. These techniques should be considered when clot retrieval is unsuitable or ineffective.

Stroke outcomes of Japanese patients with major cerebral artery occlusion in the post-alteplase, pre-MERCI era

This study examined outcomes of patients with acute ischemic stroke (AIS) with major cerebral artery occlusion after the approval of intravenous recombinant tissue-type plasminogen activator (IV rt-PA) but before approval of the MERCI retriever. We retrospectively enrolled 1170 consecutive patients with AIS and major cerebral artery occlusion (496 women; mean age, 73.9 ± 12.3 years) who were admitted within 24 hours after the onset of symptoms to 12 Japanese stroke centers between October 2005 and June 2009. Cardioembolism was a leading cause of AIS in this group (68.2%). The occlusion sites of the major cerebral arteries included the common carotid artery and internal carotid artery (ICA; 29.6%), middle cerebral artery (52.2%), and basilar artery (7.6%). Recanalization therapy (RT) was performed in 32.0% of patients (IV rt-PA, 20.0%; neuroendovascular therapy, 9.4%; combined, 2.5%). Symptomatic intracerebral hemorrhage within 36 hours with a ≥ 1-point increase in the National Institutes of Health Stroke Scale score occurred in 5.3% of the patients. At 3 months (or at hospital discharge), 29.3% of the patients had a favorable outcome (based on a modified Rankin scale score of 0-2), 23.8% were bedridden, and 15.6% died. After multivariate adjustment, RT was positively associated with a favorable outcome and negatively associated with death, whereas age, baseline National Institutes of Health Stroke Scale score, and ICA occlusion were negatively associated with a favorable outcome and positively associated with death. One-third of the patients with AIS and major cerebral artery occlusion were treated with RT, which was independently associated with favorable outcomes and death. However, 40% of the patients became bedridden or died during the post-alteplase, pre-MERCI era in Japan.

High-dose argatroban therapy for stroke: novel treatment for delayed treatment and the recanalization mechanism

BACKGROUND

There has been little effective treatment in patients with cerebral infarction at >24 hours after onset. We assessed the effects of high-dose argatroban therapy in delayed administration, and investigated the mechanism based on our clinical findings.

METHODS

Argatroban 30 mg was first administered for 15 minutes intravenously, and then 90 mg for 60 minutes followed by 60 mg for 60 minutes were infused continuously. The change of vascular obstruction caused by the treatment was assessed with magnetic resonance angiography.

RESULTS

In 4 patients studied, high-dose argatroban resulted in 100% recanalization of occluded vessels (5/5), even though argatroban was administrated >24 hours after onset. On the other hand, when an inadequate dose of argatroban was administered, a hemorrhage was identified. This supports our hypothesis that high-dose argatroban promotes recanalization by deactivating thrombin and exerting an anticoagulant effect on the vascular endothelium.

CONCLUSIONS

High-dose argatroban is an effective treatment for cerebral infarction and offers a novel therapeutic approach for delayed hospitalized patients at >24 hours after onset. Additional studies are necessary to identify the cellular and molecular mechanisms and determine the adequate dose in order to reduce risks of complication.

Endovascular stroke therapy: a single-center retrospective review

OBJECT

Endovascular treatment of acute ischemic stroke delivers direct therapy at the site of an occluded cerebral artery and can be employed beyond the 3-4.5-hour window limit set for intravenous recombinant tissue plasminogen activator. In this paper, the authors report their experience with various endovascular therapies in acute ischemic stroke.

METHODS

The authors conducted a retrospective review of their clinical database for acute ischemic stroke in large-vessel cerebral territories that underwent endovascular treatment between May 2005 and February 2009. Endovascular treatment was defined as pharmacological and/or mechanical intervention, angioplasty, stenting, or a combination of these methods. Admission National Institutes of Health Stroke Scale and the modified Rankin Scale scores were recorded. Thrombolysis in Myocardial Infarction (TIMI) scores of 0, 1, 2A, 2B, and 3 were used to define recanalization.

RESULTS

Forty procedures were performed in 39 patients, with 1 patient having sequential bilateral strokes. Nine patients were lost to follow-up after discharge. Strokes in the carotid artery circulation occurred in 82.5% of cases, and those in the vertebral-basilar territory occurred in 17.5%. The Merci device was used in 22 (55%) of 40 procedures, and the Penumbra device in 9 (22.5%) of 40. Angioplasty was performed in 15 (37.5%) of 40 procedures, and intraarterial recombinant tissue plasminogen activator was administered in 23 (57.5%) of 40 procedures. In 23 (57.5%) of 40 cases, multiple recanalization methods were used. The recanalization rate for all methods was 60%. The recanalization rate from TIMI Score 0/1 occlusions was 71.4% (20 of 28). An estimated modified Rankin Scale score of ≤ 2 was obtained in 11 (36.7%) of 30 cases. The overall mortality rate was 26.7% (8 of 30). Intracerebral hemorrhage at 24 hours postprocedure was noted in 17 (42.5%) of 40 cases, 3 (7.5%) of which were symptomatic.

CONCLUSIONS

The authors' institution performs endovascular stroke treatment with a safety and efficacy profile comparable to those of other major endovascular stroke therapy studies. Recanalization was associated with an improved clinical outcome. Protocols to maximize efficient triage of patients and better documentation of stroke treatments can assist in further studies.

Perfusion-diffusion mismatch: does it identify who will benefit from reperfusion therapy?

A method to determine which patients would benefit from reperfusion therapies after 4.5 h would greatly add to our ability to reduce the disability caused by stroke. The goal of magnetic resonance perfusion-diffusion imaging in hyperacute ischemic stroke is to identify regions of the brain that will die if untreated and will live and regain function if quickly reperfused. The clinical value of perfusion-diffusion imaging in hyperacute ischemic stroke can be proven only by demonstrating empirically in a randomized controlled trial (RCT) that there is an improvement in patient outcome that depends on the use of the neuroimaging modality to guide therapy. To date, there have been only a few RCTs that have evaluated whether perfusion-diffusion imaging can identify a subgroup of patients with ischemic stroke more than 4.5 h from onset in whom the overall benefit from reperfusion therapy outweighs the risk. None have met the rigorous design requirements of the three-group study necessary to adequately test this hypothesis, and none have even met their own criteria for demonstrating a clinical benefit. While studies are not sufficient to conclusively disprove the hypothesis there are no RCT data to support it, and thus, the clinical value of MRI perfusion-diffusion imaging in this setting remains unproven. It is worthy of further investigation in rigorously designed RCTs. However, the risks of symptomatic intracerebral hemorrhage with reperfusion therapies in acute ischemic stroke are proven. Unless RCT data are forthcoming to demonstrate that MRI perfusion-diffusion mismatch improves clinical outcome, it should not be used to guide delayed reperfusion therapy.

Pharmacological revascularization of acute ischaemic stroke: focus on challenges and novel strategies

The only currently approved treatment for acute ischaemic stroke (AIS) is alteplase, a thrombolytic agent given intravenously (IV) within 4.5 hours of symptom onset, in an attempt to reopen occluded intracerebral arteries. However, no more than 5% of all AIS patients receive IV alteplase, mainly because of too long symptom-onset-to-hospital intervals. Moreover, this strategy is effective for less than half of the patients treated within the therapeutic window. Early recanalization is the most powerful prognostic factor, and novel drugs or therapeutic strategies are primarily aimed at improving alteplase efficacy to rapidly and safely reopen the occluded arteries. Because IV alteplase-resistant thrombi are those with the largest clot burden, responsible for the most devastating brain-tissue infarctions, development of novel approved AIS therapies is an urgent priority. At present, in the absence of controlled trials, no valid recommendations can be made. However, the most promising emerging strategy is a combination of standard or low-dose IV alteplase with an intra-arterial (IA) procedure, including additional endovascular thrombolytic and/or mechanical clot retrieval. Notably, results of open trials using the IA route had relatively disappointing clinical outcomes, despite remarkable arterial recanalization rates. Controlled trials are urgently needed to evaluate strategies including an IA route. In addition, logistic and cost constraints will likely limit their routine use, even in industrialized countries. Combining of another IV drug and IV alteplase is a far less studied option, although much easier to implement. Add-on IV drugs could be an antiplatelet glycoprotein (GP) IIb/IIIa receptor antagonist, a direct thrombin inhibitor or a second thrombolytic agent, e.g. tenecteplase. However, neuroimaging to measure the clot burden and infarction size will probably be necessary to predict IV alteplase failure and the subsequent use of these eventual additional therapies.

Thromobolysis for acute ischemic stroke: is intra-arterial better than intravenous? A treatment effects model

BACKGROUND

Three randomized trials of intra-arterial thrombolysis (IAT) for acute ischemic stroke ≤ 6 hours were conducted without intravenous tissue plasminogen activator (IV-tPA) treatment of patients in the control groups now known to benefit.

METHODS

The effect of IV-tPA treatment on 130 control subjects in the Prolyse in Acute Cerebral Thromboembolism (PROACT), PROACT II, and Middle Cerebral Artery Embolism Local Fibrinolytic Intervention Trial (MELT) studies was modeled using linearly weighted time-dependent odds ratios (ORs) from pooled IV-tPA trials. In the PROACT trials, the model assumed that 50% (36/73) were treated at 4.5 hours, the median time to arteriography. For MELT, the model assumed treatment at arrival plus 90 minutes based on hospital arrival times obtained from the principal investigator. The OR of 1.31 for all 130 controls (91 presumed treated ≤ 4.5 hours; OR 1.44) was applied to the original control data to derive the adjusted control outcome, and this was compared to the IAT group. Sensitivity analyses were performed.

RESULTS

Meta-analysis of the original data revealed a statistically significant benefit for IAT (P = .03). After adjustment for the effect of IV-tPA in controls, there was no longer a significant treatment benefit for IAT (P = .26). Loss of significant IAT treatment benefit persisted if either the OR for benefit of IV-tPA or the number of treated controls was more than halved. These 3 randomized trials of IAT for acute ischemic stroke ≤ 6 hours would not likely have shown a benefit if eligible controls had been treated with IV-tPA.

CONCLUSIONS

Whether IAT is superior to IV-tPA in IV-tPA-eligible patients or better than placebo in IV-tPA-ineligible patients remains to be determined.

Endovascular treatment strategies for acute ischemic stroke

The limitations of intravenous thrombolysis therapy have paved the way for the development of novel endovascular technologies for use in the setting of acute stroke. These technologies range from direct intraarterial thrombolysis to various thrombus disruption or retrieval devices to angioplasty and stenting. The tools in the armamentarium of the neuroendovascular interventionalist enable fast, effective revascularization to be offered to a wider population of patients that may otherwise have few therapeutic options available to them. In this paper, we review the current state-of-the-art in neuroendovascular intervention for acute ischemic stroke. Particular emphasis is placed on delineating the indications and outcomes for use of these various technologies.

Endovascular therapy of 623 patients with anterior circulation stroke

BACKGROUND AND PURPOSE

Endovascular therapy of acute ischemic stroke has been shown to be beneficial for selected patients. The purpose of this study is to determine predictors of outcome in a large cohort of patients treated with intra-arterial thrombolysis, mechanical revascularization techniques, or both.

METHODS

We prospectively acquired data for 623 patients with acute cerebral infarcts in the carotid artery territory who received endovascular treatment at a single center. Logistic regression analysis was performed to determine predictors of outcome.

RESULTS

Median National Institutes of Health Stroke Scale (NIHSS) at admission was 15. Partial or complete recanalization was achieved in 70.3% of patients; it was independently associated with hypercholesterolemia (P=0.02), absence of coronary artery disease (P=0.023), and more proximal occlusion site (P<0.0001). After 3 months, 80.5% of patients had survived, and 48.9% of patients reached favorable outcome (modified Rankin scale score 0-2). Good collaterals (P<0.0001), recanalization (P=0.023), hypercholesterolemia (P=0.03), lower NIHSS at admission (P=0.001), and younger age (P<0.0001) were independent predictors for survival. More peripheral occlusion site (P<0.0001), recanalization (P<0.0001), hypercholesterolemia (P=0.002), good collaterals (P=0.002), lower NIHSS (P<0.0001), younger age (P<0.0001), absence of diabetes (P=0.002), and no previous antithrombotic therapy (P=0.036) predicted favorable outcome. Time to treatment was only a predictor of outcome, when collaterals were excluded from the model. Symptomatic intracerebral hemorrhage occurred in 5.5% and was independently predicted by poor collaterals (P=0.004).

CONCLUSIONS

Several independent predictors for outcome and complications were identified. Unlike in intravenous thrombolysis trials, time to treatment was a predictor of outcome only when collaterals were excluded from the model, indicating the important role of collaterals for the time window.

Medical therapy for ischemic stroke: review of intravenous and intra-arterial treatment options

BACKGROUND

Thrombolytic therapy is of proven and substantial benefit for select patients with acute cerebral ischemia. Diagnostic options and medical treatment options for acute stroke ischemia have undergone enormous changes in the past decades. Whereas initially stroke treatment was reduced to prevention, management of symptoms, and rehabilitation, nowadays a multitude of different fibrinolytic drugs are available. The wide availability of computed tomography in the late 1980s made thrombolysis a real therapeutic option because it allowed a fast and accurate differentiation between ischemic and hemorrhagic stroke.

METHODS

This study reviews these developments and how they have shaped our current use and understanding of thrombolytics in the treatment of acute ischemic stroke.

RESULTS

Patient selection remains a central aspect of thrombolytic treatment, and to date, the use of different fibrinolytics has been studied in over 20 large randomized trials for different clinical settings, time windows, and routes of administration. These studies included over 7000 patients, and led to our current understanding of the use of thrombolysis in acute stroke.

CONCLUSIONS

Intravenous fibrinolytic therapy within the first 3 hours of ischemic stroke onset offers substantial benefits for virtually all patients with potentially disabling deficits. In the 3- to 4.5-hour treatment window, intravenous fibrinolytic therapy has been shown to offer moderate net benefits when applied to all patients with potentially disabling deficits. Intra-arterial fibrinolytic therapy in the 3- to 6-hour window offers moderate net benefits when applied to all patients with potentially disabling deficits and large-artery cerebral thrombotic occlusions.

Antithrombotic and thrombolytic therapy for ischemic stroke: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines

OBJECTIVES

This article provides recommendations on the use of antithrombotic therapy in patients with stroke or transient ischemic attack (TIA).

METHODS

We generated treatment recommendations (Grade 1) and suggestions (Grade 2) based on high (A), moderate (B), and low (C) quality evidence.

RESULTS

In patients with acute ischemic stroke, we recommend IV recombinant tissue plasminogen activator (r-tPA) if treatment can be initiated within 3 h (Grade 1A) or 4.5 h (Grade 2C) of symptom onset; we suggest intraarterial r-tPA in patients ineligible for IV tPA if treatment can be initiated within 6 h (Grade 2C); we suggest against the use of mechanical thrombectomy (Grade 2C) although carefully selected patients may choose this intervention; and we recommend early aspirin therapy at a dose of 160 to 325 mg (Grade 1A). In patients with acute stroke and restricted mobility, we suggest the use of prophylactic-dose heparin or intermittent pneumatic compression devices (Grade 2B) and suggest against the use of elastic compression stockings (Grade 2B). In patients with a history of noncardioembolic ischemic stroke or TIA, we recommend long-term treatment with aspirin (75-100 mg once daily), clopidogrel (75 mg once daily), aspirin/extended release dipyridamole (25 mg/200 mg bid), or cilostazol (100 mg bid) over no antiplatelet therapy (Grade 1A), oral anticoagulants (Grade 1B), the combination of clopidogrel plus aspirin (Grade 1B), or triflusal (Grade 2B). Of the recommended antiplatelet regimens, we suggest clopidogrel or aspirin/extended-release dipyridamole over aspirin (Grade 2B) or cilostazol (Grade 2C). In patients with a history of stroke or TIA and atrial fibrillation we recommend oral anticoagulation over no antithrombotic therapy, aspirin, and combination therapy with aspirin and clopidogrel (Grade 1B).

CONCLUSIONS

These recommendations can help clinicians make evidence-based treatment decisions with their patients who have had strokes.

Factors and outcomes associated with recanalization timing after thrombolysis

BACKGROUND

A substantial number of acute stroke patients do not respond immediately to aggressive intra-arterial (IA) recanalization therapy. The factors and outcomes associated with timing of recanalization after IA thrombolysis, however, have not yet been determined.

METHODS

Factors and outcomes in 75 acute ischemic stroke patients treated with IA urokinase (± intravenous tissue plasminogen activator) within 6 h of onset were retrospectively assessed. Immediate recanalization (IR) was assessed by the angiogram at the end of the IA procedure, and delayed (DR) and no (NR) recanalization were assessed by 5-day MR angiography. Modified Rankin Scale (mRS) scores were determined at 7 days and 3 months.

RESULTS

Of the 75 patients, 32 (42.7%) achieved IR, 21 (28%) achieved DR, and 22 (29.3%) showed NR. Good functional outcomes (mRS score ≤2) at 7 days and 3 months were observed in 59.4 and 62.5%, respectively, of the IR group, 14.3 and 38.1% of the DR group, and 22.7 and 27.3% of the NR group (p = 0.001 for 7 days, p = 0.028 for 3 months). Multivariate analysis showed that cardioembolism [odds ratio (OR), 3.74; 95% confidence interval (CI), 1.15-12.19] and middle cerebral artery occlusion (OR, 3.23; 95% CI, 1.04-10.04) were independent predictors of IR or DR compared with NR. Age (OR, 0.86; 95% CI, 0.77-0.95) and initial NIHSS score (OR, 1.20; 95% CI, 1.04-1.37) were independent predictors of DR compared with IR.

CONCLUSIONS

Patients receiving IA thrombolysis show different clinical and radiological characteristics according to the timing of recanalization. Earlier identification of DR patients and their more efficient recanalization may improve overall clinical outcomes after IA thrombolysis.

Unilateral femoral arterial thrombosis in a dog with malignant mammary gland tumor: clinical and thermographic findings, and successful treatment with local intra-arterial administration of streptokinase

An 8-year-old intact female dog presented with a sudden onset of unilateral hindlimb paralysis of 3 days duration. Based on the history and results of physical, neurological, and histopathological examinations, and blood work, an arterial thrombosis was suspected as a complication of the hypercoagulability from a malignant mammary gland tumor. Thermography provided evidence of the unilateral femoral thrombus. Initially, thrombolysis with streptokinase administered by intravenous infusion was ineffective. Thereafter, the direct delivery of streptokinase to the site of thrombus was attempted. The approach was curative. These results suggest that thermography could describe the site of the arterial thrombus, and local intra-arterial administration of streptokinase may be an effective therapy for the canine arterial thrombosis complicated by malignant mammary gland tumor.

Emergent stent placement following intra-arterial thrombolysis for the treatment of acute basilar artery occlusion

Acute basilar artery occlusion (BAO) is a condition producing high rates of morbidity and mortality. Intravenous thrombolysis or intra-arterial thrombolysis are therapeutic options; however, the clinical outcomes remain poor. The purpose of the present study was to evaluate feasibility, safety, and efficacy of emergency stent placement following intra-arterial thrombolysis for patients with acute BAO. Thirty-six consecutive patients were treated for acute BAO using intra-arterial therapy from September 2004 to October 2009. Nine patients, with a Glasgow Coma Scale (GCS) score ranging from 8 to 12, underwent emergency stent placement following inadequate revascularization after thrombolysis. Neurological status prior to treatment was evaluated using the GCS score. Modified Rankin Scale (mRS) scores at 90 days post-treatment were used to assess functional outcome and we reviewed clinical records for frequency of procedure-related complications. Stents were deployed at the target lesion in all patients. Successful revascularization was achieved in eight of nine (88.9%) patients (residual stenosis <50%). The median GCS score prior to thrombolysis was 9 (range: 6-12) and prior to stent placement was 10 (range: 8-12). Four patients (44.4%) achieved good outcomes as determined by the mRS scale (0-2 at 90 days). Mortality was 33.3% in all procedures with one patient (11.1%) experiencing acute intrastent thrombus formation. No patient developed symptomatic intracerebral hemorrhage. Data from our small case series demonstrates that emergency stent placement following intra-arterial thrombolysis is a feasible treatment for patients with acute BAO and may reduce mortality and prevent re-occlusion of the basilar artery.

Ischemic stroke--novel therapeutic strategies

OBJECTIVES

Treatment of acute, ischemic stroke has changed markedly during the last two decades. We review existing data for optimizing modern stroke care.

RESULTS

Implementation of stroke units, giving systematic treatment and observation to stroke patients, has lead to a significant reduction in death and dependency. Introduction of intravenous rt-PA (IVT) within 3 h for selected stroke patients and recent extension of the time window to 4.5 h improved the outcome even further. Still, one must consider that IVT has several limitations, such as a narrow time window and several contraindications, and the effect is modest, particularly in strokes with a large vessel occlusion. Recanalization of the occluded vessel is a major predictor for good outcome and should be set as a goal. Intra-arterial rt-PA (IAT) and the concept of bridging therapy (IVT prior to IAT or thrombectomy with a mechanical device) may improve recanalization rates and outcome. Randomized controlled trials (RCT) are available for IAT, but not for thrombectomy with devices, and we mostly have retrospective non-controlled data. The Merci- and Penumbra system are the most studied devices, for which recent studies report acceptable safety and efficacy.

CONCLUSIONS

Sufficiently powered RCTs to evaluate the effect of thrombectomy with mechanical devices are warranted, but as the natural course of a large vessel stroke carries a devastating prognosis, a proactive recanalization approach is justified based on today's knowledge.

Fibrinolytic therapy in acute stroke

Acute ischemic stroke is a major cause of morbidity and mortality in Europe, North America, and Asia. Its treatment has completely changed over the past decade with different interventional approaches, such as intravenous trials, intra-arterial trials, combined intravenous/intra-arterial trials, and newer devices to mechanically remove the clot from intracranial arteries. Intravenous thrombolysis with tissue plaminogen activator (tPA) within 4.5 hours of symptoms onset significantly improved clinical outcomes in patients with acute ischemic stroke. Pharmacological intra-arterial thrombolysis has been shown effective until 6 hours after middle cerebral artery occlusion and offers a higher rate of recanalization compared with intravenous thrombolysis, whereas combined intravenous/ intra-arterial thrombolysis seems to be as safe as isolated intravenous thrombolysis. The more recent advances in reperfusion therapies have been done in mechanical embolus disruption or removal. Merci Retriever and Penumbra System have been approved for clot removal in brain arteries, but not as a therapeutic modality for acute ischemic stroke since it is no clear whether mechanical thrombectomy improves clinical outcome in acute stroke. However, mechanical devices are being used in clinical practice for patients who are ineligible for tPA or who have failed to respond to intravenous tPA. We summarize the results of the major thrombolytic trials and the latest neurointerventional approaches to ischemic stroke.

Management of patients with atherosclerotic carotid occlusion

OPINION STATEMENT

• Patients with acute ischemic stroke due to atherosclerotic carotid artery occlusion (ACAO) should receive intravenous tissue plasminogen activator (alteplase) if they meet eligibility criteria of the National Institute of Neurological Disorders and Stroke (NINDS) or the European Cooperative Acute Stroke Study III (ECASS III). • Patients with acute stroke due to ACAO who are not eligible for intravenous tissue plasminogen activator should receive aspirin. Heparin or heparin-like drugs do not improve outcome and should not be used. • Therapy for prevention of recurrent stroke in patients with ACAO should consist of lifestyle modifications, risk factor intervention, and antiplatelet drugs. Warfarin is not indicated. • Extracranial-intracranial bypass surgery provides no benefit over medical therapy in preventing recurrent stroke in a general population of patients with ACAO or in any subgroups selected by clinical, arteriographic, or hemodynamic criteria. • Other surgical or endovascular procedures have no proven value in treating or preventing stroke due to ACAO. • Asymptomatic carotid occlusion has a benign prognosis and requires no specific treatment other than lifestyle modification and risk factor intervention.

Impact of tissue plasminogen activator on the neurovascular unit: from clinical data to experimental evidence

About 15 million strokes occur each year worldwide. As the number one cause of morbidity and acquired disability, stroke is a major drain on public health-care funding, due to long hospital stays followed by ongoing support in the community or nursing-home care. Although during the last 10 years we have witnessed a remarkable progress in the understanding of the pathophysiology of ischemic stroke, reperfusion induced by recombinant tissue-type plasminogen activator (tPA-Actilyse) remains the only approved acute treatment by the health authorities. The objective of the present review is to provide an overview of our present knowledge about the impact of tPA on the neurovascular unit during acute ischemic stroke.

Comparison of the Incidence of parenchymal hematoma and poor outcome in patients with carotid terminus occlusion treated with intra-arterial urokinase alone or with combined IV rtPA and intra-arterial urokinase

BACKGROUND AND PURPOSE

Patients with acute CTO generally have a poor prognosis, despite IV or IA thrombolytic treatment. The goal of this study was to analyze the results of patients with CTO who had IA urokinase treatment with or without initial IV rtPA based on a bridging protocol.

MATERIALS AND METHODS

Sixteen consecutive patients with acute ischemic stroke due to CTO who had combined IV and IA or a single IA thrombolytic treatment were enrolled. The baseline characteristics and prognosis were described. The patients who did and did not develop a PH shortly after treatment were compared.

RESULTS

The mean age was 66.4 years, and the median initial NIHSS score was 17. The median dose of IA urokinase was 320,000 U, and recanalization (TICI grade II-III) was achieved in 12 patients (75%). However, 5 patients died and 10 patients had poor prognosis with mRS 5-6 at discharge. Six patients (37.5%) with a PH had a higher NIHSS score 1 day after treatment (26.7 versus 13.6, P = .002), and they had more frequent mortality (66.7% versus 10.0%, P = .018) and worse prognosis (mRS 5-6; 100% versus 40%, P = .016) at discharge than patients without PH.

CONCLUSIONS

Patients with CTO who received IA urokinase treatment based on a bridging protocol had a poor prognosis. The development of PH might affect this outcome.

Disability-adjusted life years analysis: implications for stroke research

Stroke is a prototype disorder that disables as well as kills people. The disability-adjusted life years (DALY) metric developed by the World Health Organization to measure the global burden of disease integrates healthy life years lost due to both premature mortality and living with disability. Accordingly, it is well suited to stroke research. The DALY has previously been applied only to large but relatively crude population-level data analyses, but now it is possible to calculate the DALY lost in individual stroke patients. Measuring each patient's stroke outcome with DALY lost has expanded its application to the analysis of treatment effect in acute stroke trials, delineating the poststroke complication impact, the differential weighting of discrete vascular events, and estimating a more refined stroke burden in a specific population. The DALY metric has several advantages over conventional stroke outcome measures: 1) Since the DALY measures the burden of diverse health conditions with a common metric of life years lost, stroke burden and benefits of stroke interventions can be directly compared to other health conditions and their treatments. 2) Quantifying stroke burden or interventional benefits as the life years lost or gained makes the DALY metric more intuitively accessible for public and health system planners. 3) As a continuous, equal-interval scale, the DALY analysis might be statistically more powerful than either binary or ordinal rank outcome analyses in detecting the treatment effects of clinical trials. 4) While currently employed stroke outcome measures take one-time snapshots of disability or mortality and implicitly indicate long-term health impact, the DALY explicitly indicates the burdens of living with disability for an individual's remaining life.

Angioplasty as an adjuvant therapy for the treatment of acute ischemic stroke

BACKGROUND

Different endovascular techniques can be employed to achieve vessel recanalization in acute stroke. We assessed whether an endovascular strategy that included angioplasty was safe and effectively recanalized acutely occluded intracranial vessels.

METHODS

We retrospectively reviewed 70 patients that received intra-arterial therapy for acute stroke. Patients were divided into two groups depending on whether they had received angioplasty as part of their endovascular treatment.

RESULTS

Angioplasty was used in the treatment of 35/70 patients (50%). Median baseline NIHSS was 15. The site of occlusion was at the M1 in 11 patients, M1/M2 in 3, ICA/M1 in 13 and vertebrobasilar in 8 patients. Intravenous thrombolysis was administered to 16/35 patients (46%). Angioplasty was used alone in 4 patients, in combination with intra-arterial thrombolysis in 27 and with a mechanical retrieval device or stent in 13 patients. Recanalization (TICI 2-3) was achieved in 23/35 patients (66%). Median time from symptom onset to recanalization was six hours. In patients where angioplasty was employed, symptomatic intracranial hemorrhage occurred in 2/35 (6%), which was similar to patients that were not treated with angioplasty. A favorable functional outcome (mRS=2) was achieved in 20% (7/35) at 24 hour and 34% (12/35) at one month. All patients that had a favorable outcome had recanalized.

CONCLUSION

In this small cohort, an endovascular treatment strategy that employed angioplasty was safe and effectively recanalized acutely occluded intracranial vessels. Angioplasty should be considered as a potential treatment option in interventional acute stroke trials.

Acute stroke intervention

This review summarizes the current state-of-the-art regarding the endovascular management of acute ischemic stroke. Beginning with intravenous tissue plasminogen activator, this paper traces the gradual shift of systemic thrombolysis from a competing to complementary treatment modality. Intra-arterial thrombolysis, mechanical thrombectomy with the Merci (Concentric Medical, Mountain View, California) and Penumbra (Penumbra, Inc., Alameda, California) systems, angioplasty, primary intracranial stenting, and emerging stentriever devices are sequentially reviewed. Ultimately, this paper lays the foundation for current endovascular stroke management and considers future areas of progress and research.

Intra-arterial therapy for acute ischemic stroke

Intra-arterial therapy (IAT) for acute ischemic stroke refers to endovascular catheter-based approaches to achieve recanalization using mechanical clot disruption, locally injected thrombolytic agents or both. IAT may be used in addition to intravenous tissue plasminogen activator (tPA) or in patients who do not qualify for tPA, usually because they are outside the approved 3-h timeframe window or have contraindications, such as elevated international normalized ratio or partial thromboplastin time. Recanalization rates correlate with clinical improvement, and with the newest catheters it is possible to achieve recanalization in roughly 80% of patients treated. However, while the catheters are approved by the Food and Drug Administration, there are still no randomized trial data demonstrating the role of current IAT therapy vs either tPA or standard management. IAT is reserved for patients with large artery occlusions in the basilar, distal carotid, or proximal middle cerebral arteries. Imaging the penumbra using magnetic resonance imaging or computed tomographic perfusion is currently the most frequently used way to identify patients who might benefit. However, the imaging and clinical criteria for identifying which patients benefit, and perhaps more importantly those who will do poorly despite IAT, remain unclear.

Improving reperfusion therapy for acute ischaemic stroke

BACKGROUND

The first generation of clinical reperfusion treatment, intravenous (IV) fibrinolysis with tissue plasminogen activator (tPA), was a transformative breakthrough in stroke care, but is far from ideal.

OBJECTIVES

TO survey emerging strategies to increase the efficacy and safety of cerebral reperfusion therapy.

METHODS

Narrative review.

RESULTS AND CONCLUSIONS

Innovative IV pharmacologic reperfusion strategies include: extending IV tPA use to patients with mild deficits; developing novel fibrinolytic agents (tenecteplase, desmetolplase, plasmin); using ultrasound to enhance enzymatic fibrinolysis; combination clot lysis therapies (fibrinolytics with GPIIb/IIIa agents or direct thrombin inhibitors); co-administration of MMP-9 inhibitors to deter haemorrhagic transformation; and prehospital neuroprotection to support threatened tissues until reperfusion. Endovascular recanalisation strategies are rapidly evolving, and include intra-arterial fibrinolysis, mechanical clot retrieval, suction thrombectomy, and primary stenting. Combined approaches appear especially promising, using IV fibrinolysis to rapidly initiate reperfusion, mechanical endovascular treatment to debulk large, proximal thrombi, and intra-arterial (IA) fibrinolysis to clear residual distal thrombus elements and emboli.

Current status of endovascular stroke treatment

The management of acute ischemic stroke is rapidly developing.Although acute ischemic stroke is a major cause of adult disability and death, the number of patients requiring emergency endovascular intervention remains unknown, but is a fraction of the overall stroke population. Public health initiatives endeavor to raise public awareness about acute stroke to improve triage for emergency treatment, and the medical community is working to develop stroke services at community and academic medical centers throughout the United States. There is an Accreditation Council for Graduate Medical Education–approved pathway for training in endovascular surgical neuroradiology, the specialty designed to train physicians specifically to treat cerebrovascular diseases. Primary and comprehensive stroke center designations have been defined, yet questions remain about the best delivery model. Telemedicine is available to help community medical centers cope with the complexity of stroke triage and treatment. Should comprehensive care be provided at every community center, or should patients with complex medical needs be triaged to major stroke centers with high-level surgical,intensive care, and endovascular capabilities? Although the answers to these and other questions about stroke care delivery remain unanswered owing to the paucity of empirical data, we are convinced that stroke care regionalization is crucial for delivery of high-quality comprehensive ischemic stroke treatment. A stroke team available 24 hours per day, 7 days per week requires specialty skills in stroke neurology, endovascular surgical neuroradiology, neurosurgery, neurointensive care, anesthesiology, nursing, and technical support for optimal success. Several physician groups with divergent training backgrounds (i.e., interventional neuroradiology, neurosurgery,neurology, peripheral interventional radiology, and cardiology) lay claim to the treatment of stroke patients,particularly the endovascular or interventional methods. Few would challenge neurologists over the responsibility for emergency evaluation and triage of stroke victims for intra intravenous fibrinolysis, even though emergency physicians are most commonly the first to evaluate these patients. There are many unanswered questions about the role of imaging in defining best treatment. Perfusion imaging with CT or MRI appears to have relevance even though its role remains undefined and is the subject of ongoing research. Meanwhile, investigators are exploring new, and perhaps more specific,imaging methods with cerebral metabolic rate of oxygen and cellular acid-base imbalance. There are currently 6 ongoing trials of stroke intervention, many with proprietary technologies and private funding, competing for the same patient population as multicenter trials funded by the NIH. At the same time, much of the interventional stroke treatment currently occurs outside of trials in the community and academic settings without the collection of much-needed data. Market forces will certainly shape future stroke therapy, but it is unclear whether the current combination of private and public funding for these endeavors is the best method of development.

Intra-arterial Thrombolysis or Stent Placement During Endovascular Treatment for Acute Ischemic Stroke Leads to the Highest Recanalization Rate: Results of a Multicenter Retrospective Study

BACKGROUND:

Reperfusion therapy for acute ischemic stroke (AIS) is rapidly evolving, with the development of multiple endovascular modalities that can be used alone or in combination.

OBJECTIVE:

To determine which pharmacologic or mechanical modality may be associated with increased rates of recanalization.

METHODS:

A cohort of 1122 patients with AIS involving the anterior circulation treated at 13 stroke centers underwent intra-arterial (IA) therapy within 8 hours of symptom onset. Demographic information, admission National Institutes of Health Stroke Scale (NIHSS), mechanical and pharmacologic treatments used, recanalization grade, and hemorrhagic complications were recorded.

RESULTS:

The mean age was 67 ± 16 years and the median NIHSS was 17. The sites of arterial occlusion before treatment were M1 middle cerebral artery (MCA) in 561 (50%) patients, carotid terminus in 214 (19%) patients, M2 MCA in 171 (15%) patients, tandem occlusions in 141 (13%) patients, and isolated extracranial internal carotid artery occlusion in 35 (3%) patients. Therapeutic interventions included multimodal therapy in 584 (52%) patients, pharmacologic therapy only in 264 (24%) patients, and mechanical therapy only in 274 (24%) patients. Patients treated with multimodal therapy had a significantly higher Thrombolysis in Myocardial Infarction 2 or 3 recanalization rate (435 patients [74%]) compared with pharmacologic therapy only (160 patients, [61%]) or mechanical only therapy (173 patients [63%]), P &lt; .001. In binary logistic regression modeling, independent predictors of Thrombolysis in Myocardial Infarction 2 or 3 recanalization were use of IA thrombolytic OR 1.58 (1.21-2.08), P &lt; .001 and stent deployment 1.91 (1.23-2.96), P &lt; .001.

CONCLUSION:

Multimodal therapy has significantly higher recanalization rates compared with pharmacologic or mechanical therapy. Among the individual treatment modalities, stent deployment or IA thrombolytics increase the chance of recanalization.

Safety of high doses of urokinase and reteplase for acute ischemic stroke

BACKGROUND AND PURPOSE

ET is considered in selected patients with AIS with persistent arterial occlusion after receiving IVT. Limited data exist on the safety of IA high doses of UK and RT for ET. We investigated any correlation between IA doses of UK or RT and safety outcomes in patients who underwent ET.

MATERIALS AND METHODS

We identified all patients from our stroke registry who received UK or RT for ET from 1998 to 2008. Demographics, baseline National Institutes of Health Stroke Scale scores, recanalization rates, rates of attempted MT, mortality, SICH, and discharge modified Rankin Scale scores were collected.

RESULTS

Of 197 patients; 72 received UK and 125 received RT. More than 90% of patients in both groups had received prior IVT. The median IA dose of UK was 200,000 U (range, 25,000-1,500,000 U) and of RT was 2 mg (range, 1-8 mg). Concurrent MT was attempted in 59.7% of UK-treated patients and 72.0% of RT-treated patients, with SICH rates of 4.2% and 8.0%, respectively. Logistic regression adjusting for prior IVT and MT revealed no correlation between SICH and doses of UK (OR, 1.00; 95% CI, 0.99-1.00; P = .94) or RT (OR, 0.803; 95% CI, 0.48-1.33; P = .39). There was no correlation between mortality and doses of UK (OR, 1.00; 95% CI, 0.99-1.00; P = .51) or RT (OR, 1.048; 95% CI, 0.77-1.42; P = .75).

CONCLUSIONS

High IA doses of UK and RT may be safe when given with or without MT in patients with AIS despite receiving a full dose of intravenous recombinant tissue plasminogen activator. These results need prospective validation.

Pharmacological and non-pharmacological recanalization strategies in acute ischemic stroke

According to the guidelines of the European Stroke Organization (ESO) and the American Stroke Association (ASA), acute stroke patients should be managed at stroke units that include well organized pre- and in-hospital care. In ischemic stroke the restoration of blood flow has to occur within a limited time window that is accomplished by fibrinolytic therapy. Newer generation thrombolytic agents (alteplase, pro-urokinase, reteplase, tenecteplase, desmoteplase) have shorter half-life and are more fibrin-specific. Only alteplase has Food and Drug Administration (FDA) approval for the treatment of acute stroke (1996). The National Institute of Neurological Disorders and Stroke (NINDS) trial proved that alteplase was effective in all subtypes of ischemic strokes within the first 3 h. In the European cooperative acute stroke study III trial, intravenous (IV) alteplase therapy was found to be safe and effective (with some restrictions) if applied within the first 3-4.5 h. In middle cerebral artery (MCA) occlusion additional transcranial Doppler insonication may improve the breakdown of the blood clot. According to the ESO and ASA guidelines, intra-arterial (IA) thrombolysis is an option for recanalization within 6 h of MCA occlusion. Further trials on the IA therapy are needed, as previous studies have involved relatively small number of patients (compared to IV trials) and the optimal IA dose of alteplase has not been determined (20-30 mg is used most commonly in 2 h). Patients undergoing combined (IV + IA) thrombolysis had significantly better outcome than the placebo group or the IV therapy alone in the NINDS trial (Interventional Management of Stroke trials). If thrombolysis fails or it is contraindicated, mechanical devices [e.g., mechanical embolus removal in cerebral ischemia (MERCI)- approved in 2004] might be used to remove the occluding clot. Stenting can also be an option in case of acute internal carotid artery occlusion in the future. An intra-aortic balloon was used to increase the collateral blood flow in the Safety and Efficacy of NeuroFlo(™) Technology in Ischemic Stroke trial (results are under evaluation). Currently, there is no approved effective neuroprotective drug.

Simultaneous combined intravenous recombinant tissue plasminogen activator and endovascular therapy for hyperacute middle cerebral artery m1 occlusion

We investigated the efficacy and safety of combined intravenous (IV) recombinant tissue plasminogen activator (rtPA) and simultaneous endovascular therapy (ET) for hyperacute middle cerebral artery (MCA) M1 occlusion. Between October 2005 and April 2007, in the combined group, 22 patients eligible for IV rtPA, who were diagnosed as having MCA M1 occlusion, were treated with IV rtPA and simultaneous ET was initiated as soon as possible. The other patients were treated with IV rtPA alone (IV group A: n = 11). Between May 2007 and November 2008, all patients eligible for IV rtPA, who were diagnosed as having MCA M1 occlusion, underwent thrombolysis by IV rtPA alone (IV group B: n = 24). The improvement of the National Institutes of Health Stroke Scale score at 24 hours was highest in the combined group (10 ± 4.1). In contrast, it was 5.1 ± 4.7 in the IV group A (P = 0.017) and 5.6 ± 5.6 in IV group B (P = 0.006). In the combined group, successful recanalization was observed in 18 of 22 patients with one symptomatic intracranial hemorrhage. The rate of mRS0-2 at three months was highest in the combined group, 36% in the IV group A and 33% in the IV group B (P = 0.008).Simultaneous treatment with IV rtPA and ET improved the clinical outcome of MCA M1 occlusion without a significant increase of adverse effects in our study.