Current evidence for endovascular therapy in stroke and remaining uncertainties

Class 1 level A evidence now supports endovascular thrombectomy as best practice in the management of large vessel occlusion acute ischaemic stroke. However, significant questions pertaining to initial imaging, radiological assessment, patient selection and therapeutic limits remain unanswered. A specific cohort of patients who benefit from endovascular thrombectomy has been established, although current uncertainties regarding selection of those not meeting top‐tier evidence criteria may potentially deny certain patients the benefit of intervention. This is of particular relevance in patients presenting in a delayed manner. Whilst superior outcomes are achieved with reduced time to endovascular reperfusion, denying patients intervention based on symptom duration alone may not be appropriate. Advanced understanding of ischaemic stroke pathophysiology supports an individualized approach to patient evaluation, given variance in the rate of ischaemic core progression and the extent of salvageable penumbra. Physiological imaging techniques may therefore be utilized to better inform patient selection for endovascular thrombectomy and evidence suggests that a transition from time‐based to tissue‐based therapeutic thresholds may be of greater value. Multiple ongoing randomized controlled trials aim to further define the benefit of endovascular thrombectomy and it is hoped that these results will advance, and possibly broaden, patient selection criteria to ensure that maximum benefit from the intervention may be achieved.     

静脉溶栓桥接治疗急性缺血性卒中

静脉溶栓是治疗急性缺血性卒中的首选方法,但在大血管闭塞性卒中患者中的血管再通率较低.以血管内机械血栓切除术为代表的血管内治疗能有效使缺血性卒中患者闭塞血管再通和改善转归.文章对静脉溶栓桥接治疗的现状和发展方向进行了综述.     

No space left for intravenous thrombolysis in acute stroke: CONS

Recent successful clinical trials of endovascular thrombectomy for large artery ischaemic stroke have established the value of this treatment modality as an adjunct to intravenous thrombolysis, not as an alternative: thrombectomy delivery was undertaken in the context of highly efficient networks for acute thrombolysis delivery and the great majority of patients received IV thrombolytic drug treatment. Even for the minority of acute stroke patients for whom thrombectomy is potentially relevant, access will be limited by geography and service infrastructure. Developments in intravenous thrombolysis in the near future will likely produce safer and more effective intravenous treatments. Intravenous thrombolysis will remain the first line of treatment for the great majority of acute stroke patients.     

Advances in endovascular treatment of acute ischaemic stroke

Over the past decade, there have been rapid advancements in ischaemic stroke reperfusion treatments. However, clear clinical benefit is yet to be shown in large clinical trials. In this review, the major studies in different types of endovascular treatments including intra‐arterial thrombolysis, aspiration devices, mechanical clot retrievers and the new stent retrievers are discussed. First‐generation mechanical thrombectomy devices such as the MERCI Retriever (Stryker, Kalamazoo, MI, USA) and Penumbra aspiration device (Penumbra Inc., Alameda, CA, USA) demonstrated safety and higher rates of recanalisation in the MERCI and Penumbra Pivotal Stroke Trial; however, there was no significant improvement in clinical outcome. Second‐generation endovascular stent retrieval devices Solitaire (ev3 Neurovascular, Irvine, CA, USA) and Trevo (Stryker) have shown promising results. In preliminary trials, SOLITAIRE with the Intention for Thrombectomy (SWIFT) and Thrombectomy Revascularization of Large Vessel Occlusions (TREVO), both showed rates of recanalisation close to 90% and significantly improved clinical outcomes compared with the MERCI study, but the recent landmark studies for endovascular treatment (Interventional Management of Stroke (IMS III), Mechanical Retrieval and Recanalisation of Stroke Clots Using Embolectomy (MR‐RESCUE) and SYNTHESIS) did not show any clinical benefit from endovascular treatment compared with standard intravenous therapy. However, moving forward, the recent Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischaemic Stroke in the Netherlands (MR‐CLEAN) study results have shown marked improvements in recanalisation, reperfusion and functional outcome in patients receiving endovascular treatment (97% using stent retrievers) within 6 h in addition to standard medical care. Overall, although evidence regarding the efficacy of endovascular treatment in acute stroke has been equivocal, recent publications of large multicentre randomised controlled trials indicate benefit of intra‐arterial stent retriever reperfusion in patients selected by appropriate imaging and treated early by experienced operators, and it will likely remain an important adjunct to established medical treatment with intravenous tPA.     

New Cerebral Microbleeds After Mechanical Thrombectomy for Large-Vessel Occlusion Strokes

The interval appearance of cerebral microbleeds (CMBs) after endovascular treatment has never been described. We investigated the frequency and predictors of new CMBs that developed shortly after mechanical thrombectomy for acute ischemic stroke, and its impact on clinical outcome.We retrospectively analyzed patients with large-vessel occlusion strokes treated with Merci Retriever, Penumbra System, or stent-retriever devices. Serial T2∗-weighted gradient-recall echo (GRE) magnetic resonance imaging (MRI) before and 48 h after endovascular thrombectomy were assessed to identify new CMBs. We examined independent factors associated with new CMBs after mechanical thrombectomy. We analyzed the association of the presence, burden, and distribution of new CMBs with clinical outcome.A total of 187 consecutive patients with serial GRE were enrolled in this study. CMBs were evident in 36 (19.3%) patients before mechanical thrombectomy. New CMBs occurred in 41 (21.9%) patients after mechanical thrombectomy. Of the 68 new CMBs, 45 appeared in the lobar location, 18 in the deep location and 5 in the infratentorial location. The presence of baseline CMBs was associated with new CMBs after mechanical thrombectomy (OR 5.38; 95% CI 2.13–13.59; P < 0.001), no matter whether the patients were treated primarily with mechanical thrombectomy or with intravenous thrombolysis followed by mechanical thrombectomy. Patients with new CMBs did not have increased rates of hemorrhagic transformation, in-hospital mortality, and modified Rankin Scale score 4 to 6 at discharge.New CMBs are common after mechanical thrombectomy in one-fifth of patients with acute ischemic stroke. Baseline CMBs before mechanical thrombectomy predicts the development of new CMBs. New CMBs after mechanical thrombectomy do not influence clinical outcome.     

The endovascular management of intracranial vascular disease including the MERCI device

Opinion statement The prompt and aggressive management of acute stroke has become the standard of care as public awareness and the available successful treatment options both increase. The intravenous administration of tissue plasminogen activator within an established treatment window has been determined through large well-designed studies. The endovascular strategies for acute stroke have evolved significantly over the past 5 years and have been prompted by the limits of the intravenous treatment, as well as by the desire to demonstrate improved recanalization rates and improved long-term outcomes. Among these interventional treatment options are the intra-arterial administration of tissue plasminogen activator and newer antiplatelet agents, mechanical thrombectomy with the MERCI device, and intracranial angioplasty and stenting. This article outlines the major studies that have defined the current field of acute stroke management and discusses the basic treatment paradigms that are commonly used today.     

The endovascular management of intracranial vascular disease including the MERCI device

The prompt and aggressive management of acute stroke has become the standard of care as public awareness and the available successful treatment options both increase. The intravenous administration of tissue plasminogen activator within an established treatment window has been determined through large well-designed studies. The endovascular strategies for acute stroke have evolved significantly over the past 5 years and have been prompted by the limits of the intravenous treatment, as well as by the desire to demonstrate improved recanalization rates and improved long-term outcomes. Among these interventional treatment options are the intra-arterial administration of tissue plasminogen activator and newer antiplatelet agents, mechanical thrombectomy with the MERCI device, and intracranial angioplasty and stenting. This article outlines the major studies that have defined the current field of acute stroke management and discusses the basic treatment paradigms that are commonly utilized today.     

前循环卒中血管内血栓切除术治疗：随机对照试验的汇总分析

目的：评价前循环卒中患者血管内血栓切除术治疗的有效性和安全性。方法检索PubMed、EMBASE、Cochrane、Clinical Trials 数据库和相关补充资料,纳入在前循环卒中患者中比较静脉溶栓治疗与血管内血栓切除术治疗的随机临床对照试验,进行偏倚风险评价,提取研究基本特征和90 d时转归良好(定义为改良 Rankin 量表评分0~2分)、死亡以及有症状颅内出血(symptomatic intracranial hemorrhage, sICH)等数据,应用 Review Manager 5．3软件进行统计学分析。结果共纳入10项研究,其中血管内治疗组共1557例患者,静脉溶栓治疗组共1359例患者。纳入研究的质量整体较高,产生偏倚的风险较低。血管内治疗组转归良好率显著高于静脉溶栓对照组[优势比(odds ratio, OR)2．15,95%可信区间(confidence interval, CI)1．34~3．46;P <0．01],90 d死亡风险与静脉溶栓治疗组无显性差异(OR 0．86,95% CI 0．69~1．06;P =0．16),但 sICH 风险增高存在临界性统计学意义(OR 1．35,95% CI 1．00~1．84;P =0．05)。结论前循环卒中患者行血管内血栓切除术治疗的有效性显著优于静脉溶栓治疗,但在安全性方面仍需进一步评价。     

机械取栓装置在缺血性卒中患者治疗中的应用

目前,在发病4．5h内进行静脉溶栓仍然是治疗急性缺血性卒中患者的最有效方法。对于不符合静脉溶栓治疗标准、静脉溶栓后症状无明显改善甚至恶化的患者,血管内介入治疗是一种安全的替代治疗方法。经动脉机械取栓装置能实现迅速和完全的血管再通,为急性缺血性卒中患者提供了更多的治疗选择。文章对近年来机械取栓装置相关的技术演变和临床试验进行了综述。     

Treatment of acute stroke: an update

Stroke is the second leading cause of global mortality after coronary heart disease, and a major cause of neurological disability. About 17 million strokes occur worldwide each year. Patients with stroke often require long‐term rehabilitation following the acute phase, with ongoing support from the community and nursing home care. Thus, stroke is a devastating disease and a major economic burden on society. In this overview, we discuss current strategies for specific treatment of stroke in the acute phase, focusing on intravenous thrombolysis and mechanical thrombectomy. We will consider two important issues related to intravenous thrombolysis treatments: (i) how to shorten the delay between stroke onset and treatment and (ii) how to reduce the risk of symptomatic intracerebral haemorrhage. Intravenous thrombolysis has been approved treatment for acute ischaemic stroke in most countries for more than 10 years, with rapid development towards new treatment strategies during that time. Mechanical thrombectomy using a new generation of endovascular tools, stent retrievers, is found to improve functional outcome in combination with pharmacological thrombolysis when indicated. There is an urgent need to increase public awareness of how to recognize a stroke and seek immediate attention from the healthcare system, as well as shorten delays in prehospital and within‐hospital settings.     

Acute stroke therapy: A review

This review summarizes the modern early diagnosis and acute phase treatment of acute stroke. The guidelines for treatment of acute ischemic stroke underwent major changes in 2015 and endovascular therapy (catheter-based mechanical thrombectomy with a stent retriever) became the class IA indication for patients presenting within less than 6 h from symptom onset who have proven occlusion of large intracerebral artery in anterior circulation. Acute stroke care organization should enable to perform effective revascularization therapy as soon as possible after the initial brain imaging whenever this examination provides indication for the procedure.     

Stable Clinical Outcomes When a Stroke Thrombectomy Program Is Started in an Experienced Cardiology Cath Lab

ObjectivesThis study analyzed the learning curve effect when a new stroke thrombectomy program was initiated in a cardiac cath lab in close cooperation with neurologists and radiologists.BackgroundMechanical thrombectomy has proven to be the best treatment option for ischemic stroke patients, but this method is not widely available.MethodsAn endovascular treatment program for acute ischemic strokes was established in the cardiac cath lab of a tertiary university hospital in 2012. The decision to perform catheter-based thrombectomy was made by a neurologist and was based on acute stroke clinical symptoms and computed tomography angiographic findings. Patients with a large vessel occlusion of either anterior or posterior circulation were enrolled. The primary endpoint was the functional neurological outcome (Modified Rankin Scale [mRS] score) of the patient at 3 months. A total of 333 patients were enrolled between October 2012 and December 2019.ResultsThe clinical (mRS) outcomes did not vary significantly across years 2012 to 2019 (mRS 0 to 2 was achieved in 47.9% of patients). Symptomatic intracerebral hemorrhage occurred in 19 patients (5.7%). Embolization in a new vascular territory occurred in 6 patients (1.8%).ConclusionsWhen a catheter-based thrombectomy program was initiated in an experienced cardiac cath lab in close cooperation between cardiologists, neurologists, and radiologists, outcomes were comparable to those of neuroradiology centers. The desired clinical results were achieved from the onset of the program, without any signs of a learning curve effect. These findings support the potential role of interventional cardiac cath labs in the treatment of acute stroke in regions where this therapy is not readily available due to the lack of neurointerventionalists.     

Nouveautés dans la prise en charge de l’infarctus cérébral en 2014 : ce que le cardiologue doit savoir

Introduction

Interventional cardiology procedures are regularly exposed to ischemic neurological complications. IV fibrinolysis is the only approved treatment in ischemic stroke but is very often contraindicated in these situations. Many techniques of interventional neuroradiology (mechanical thrombectomy) have been developed over the past years and are used to treat these patients.

Observation

We report the case of two patients who were admitted in emergency for ischemic stroke with contraindication to IV fibrinolysis (cardioversion for atrial fibrillation under anticoagulation; 24 hours after carotid surgery). These patients were treated by endovascular thrombectomy procedure.

Discussion

After validation of IV fibrinolysis within 4.5 hours after stroke onset, techniques of mechanical thrombectomy have gradually been developed, either as a complementary treatment or as an alternative in the case of CI to fibrinolysis. These endovascular thrombectomy devices currently allow recanalization of proximal cerebral occlusions, which correlates with a favorable clinical prognosis. A review of the literature is provided, along with a discussion about the techniques currently being improved, their advantages and disadvantages and the selection of patients that can benefit from endovascular procedures.

Conclusion

In the case of a sudden occurrence of a neurological deficit during a cardiovascular procedure, a “thrombolysis alert” should be triggered. This will permit the rapid establishment of a clinico-radiological report for selecting stroke patients eligible for a procedure of recanalization by thrombolysis and/or mechanical thrombectomy.     

Successful Aspiration and Rheolytic Thrombectomy of a Renal Artery Infarct and Review of the Current Literature

The use of revascularization techniques including angioplasty, thrombectomy, and stenting in the coronary, cerebral, and peripheral arteries has revolutionized the entire field of endovascular therapeutics. In renal thromboembolism, the classic treatment has been anticoagulation with possible thrombolysis and surgical thrombectomy. The role of endovascular therapy in renal thromboembolism remains controversial. There are a few anecdotal reports about the use of aspiration and rheolytic thrombectomy in the renal arteries. We present a case of acute renal infarction resulting from systemic embolism secondary to atrial fibrillation. This was treated with revascularization, including aspiration and rheolytic thrombectomy, with excellent results.     

No space left for intravenous thrombolysis in acute stroke: PROS

Five recently published RCTs (MR CLEAN, EXTEND-IA, SWIFT PRIME, REVASCAT and ESCAPE) employing mechanical thrombectomy with modern stent retriever devices clearly demonstrated the superiority of endovascular treatment compared to thrombolysis alone, which is now considered standard first-line therapy for selected patients with acute severe ischemic stroke and large vessel in the anterior circulation. RCT results led to recommendations outlined in “Mechanical thrombectomy in acute ischemic stroke by ESO-Karolinska Stroke Update 2014/2015, supported by ESO, ESMINT, ESNR and EAN”. Moreover, endovascular procedures in the 5 RCTs to date were performed at high-volume referral centers with, in some trials, rigid requirements for the interventionalist to participate, which may have contributed substantially to the excellent results, supporting the concept of centralization of intra-arterial thrombolysis resources and expertise. Therefore, patients with suspected large-artery occlusion and deemed candidates for thrombectomy, should be treated at a Comprehensive Stroke Centre with 24/7 endovascular treatment services. There seems to be limited space left for intravenous thrombolysis alone in acute stroke patients with large-vessel occlusions as thrombectomy plus thrombolysis continues to be reported as being superior with regard to outcome.     

Endovascular stroke therapy

BackgroundFollowing the development of intravenous thrombolysis as a successful treatment for ischaemic stroke, advances in neurointerventional radiology have facilitated endovascular approaches to treatment. This article reviews the available endovascular therapeutic options and their evidence-base.SummaryInitial studies demonstrated that endovascular treatment of ischaemic stroke with intra-arterial thrombolysis and/or the use of clot-retrieval, thrombus aspiration and stent-retriever devices produced early recanalisation and reperfusion and improved neurological outcome. More recent randomised trials, however, have failed to show translation of recanalisation into successful clinical outcome with ‘time to treatment’ proving crucial. In this rapidly evolving field, combined therapy incorporating intravenous and intra-arterial thrombolysis in combination with endovascular clot-retrieval has been developed and further studies are expected to yield better evidence to guide the optimal treatment of acute cerebral ischaemia.     

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.     

Acute Stroke Intervention

Ischemic strokes will make up most (>80%) of the three-quarters of a million strokes that will occur in Americans this year. Reperfusion therapy is the fundamental strategy for the treatment of acute ischemic stroke. Reperfusion therapy may be accomplished noninvasively (intravenous thrombolysis) or invasively with catheter-based treatments (intra-arterial thrombolysis, thrombectomy, or angioplasty). Currently, a large majority of patients with acute ischemic stroke do not receive any form of reperfusion therapy owing to their delayed presentation (>3 hours) and lack of skilled man power for on-demand endovascular treatment. Paradoxically, improved success rates for reperfusion have been reported with the newer thrombectomy catheters, called “stentreivers.” An option for broadening access for patients who need endovascular therapy would be to use interventional cardiologists with carotid stent experience who can help to provide 24×7×365 coverage.     

Carotid Stenting With Antithrombotic Agents and Intracranial Thrombectomy Leads to the Highest Recanalization Rate in Patients With Acute Stroke With Tandem Lesions

Objectives

The aim of this study was to identify the optimal endovascular approach in patients with acute stroke with tandem lesions.

Efficacy and safety of mechanical thrombectomy for cardioembolic stroke: A protocol for systematic review and meta-analysis

Background:Several randomized clinical trials have demonstrated the safety and efficiency of mechanical thrombectomy in the management of acute ischaemic stroke caused by larger vessel occlusion. According to the trial of Org 10172 in Acute Stroke Treatment (TOAST) classification, acute ischaemic stroke can be divided into cardioembolic stroke and non-cardioembolic stroke. Previous studies have shown that mechanical thrombectomy in cardioembolic stroke with intracranial large artery occlusion has a poor prognosis. The reason may be that the old emboli are hard, making it difficult to remove. However, recent evidence shows that mechanical thrombectomy is also effective and safe in patients with cardioembolic stroke. Therefore, the aim of this study is to evaluate the efficacy and safety of mechanical thrombectomy for cardioembolic stroke.Methods:The electronic database, including PubMed, Cochrane Library, EMBASE, the China National Knowledge Infrastructure (CNKI), China Biology Medicine disc (CBM), VIP database, and Wan-fang database, were thoroughly retrieved from inception to December 1, 2021, without language restrictions. All randomized controlled trials that evaluated the efficacy and safety of mechanical thrombectomy in the treatment of cardioembolic stroke will be included. Primary outcomes will include vascular recanalization rate and score scale. Two authors will independently scan the articles searched, extract the data from articles included, and assess the risk of bias by Cochrane tool of risk of bias. Disagreements will be resolved by discussion among authors. All analysis will be performed based on the Cochrane Handbook for Systematic Reviews of Interventions. Dichotomous variables will be reported as risk ratio or odds ratio with 95% confidence intervals and continuous variables will be summarized as mean difference or standard mean difference with 95% confidence intervals.Results:This review will be to assess the efficacy and safety of mechanical thrombectomy for cardioembolic stroke.Conclusions:The results of our findings may be helpful for clinicians and health professionals to re-examine the clinical decision-making in the treatment of cardioembolic stroke, promising way for treatment of patients with cardioembolic stroke.Systematic review registration number:INPLASY2020120035