Stent-assisted intracranial recanalization for acute stroke: early results

Rescue Stenting for Refractory Large Vessel Occlusions in the Thrombectomy Era: Intracranial Use of Coronary Stents in Low-mid Economic Settings

Background: Failed mechanical thrombectomy due to a refractory emergent large vessel occlusion (RELVO) in patients presenting with an acute stroke poses a major challenge to the outcomes.

Objective: We demonstrate the use of coronary stents in the intracranial circulation as rescue stenting for an already expensive mechanical thrombectomy procedure in a mid-low socioeconomic setting.

Methods: A retrospective, multicenter study was conducted between December 2015 and January 2021. The studied cohort were patients who required the use of a rescue stenting using a coronary stent for emergent large vessel occlusion to avoid failed recanalization. Failed recanalization was defined as failed vessel recanalization after at least two passes. Patient demographic data, procedure specifics, type of stent used, and procedural outcomes were collected.

Results: A total of 26 patients with acute ischemic stroke were included from eight different centers across India. Out of 26 patients, 19 (73.0%) were male and seven were female (26.9%). The mean age was 53.6 years, the youngest patient was 23 years old and the eldest was 68 years old. Seven patients (26.9%) had posterior circulation stroke due to occlusion of the vertebral or basilar artery and 19 patients (73.0%) had anterior circulation stroke median NIHSS at presentation was 16 (range 10 to 28) in anterior circulation stroke and 24 (range 16 to 30) in posterior circulation stroke. Intravenous thrombolysis with tissue plasminogen activator (IV tPA) was given in three patients (11.5%). The hospital course of two patients was complicated by symptomatic intracranial hemorrhage (sICH), which was fatal. Favorable revascularization outcome and favorable functional outcome was achieved in 22 patients (84.6%), three patients passed away (11.5%), and one patient was lost to follow up.

Conclusions: Overall, our study finds that rescue stenting using coronary stents can potentially improve outcomes in refractory large vessel occlusions while minimizing costs in low-mid economic settings.

Stentrievers : An engineering review

The advent of endovascular therapy for acute large vessel occlusion has revolutionized stroke treatment. Timely access to endovascular therapy, and the ability to restore intracranial flow in a safe, efficient, and efficacious manner has been critical to the success of the thrombectomy procedure. The stentriever has been a mainstay of endovascular stroke therapy, and current guidelines recommend the usage of stentrievers in the treatment of large vessel occlusion stroke. Despite the success of existing stentrievers, there continues to be significant development in the field, with newer stentrievers attempting to improve on each of the three key aspects of the thrombectomy procedure. Here, we elucidate the technical requirements that a stentriever must fulfill. We then review the basic variables of stent design, including the raw material and its form, fabrication method, geometric configuration, and further additions. Lastly, a selection of stentrievers from successive generations are reviewed using these engineering parameters, and clinical data is presented. Further avenues of stentriever development and testing are also presented.

Locked-In Syndrome Following Cervical Manipulation by a Chiropractor: A Case Report

Introduction

Vertebrobasilar occlusion poses difficult diagnostic issues and even when properly diagnosed has a poor prognosis. Newer studies highlight a better outcome when thrombectomy was carried out between six and twenty-four hours after an initial diagnosis of stroke. This paper reports a case where a patient suffered a vertebrobasilar stroke secondary to a traumatic bilateral vertebral arteries dissection was treated with late thrombectomy.

Case presentation

A 34-year-old woman was manipulated on the cervical spinal column by a chiropractor. Following three weeks of cervical pain, she presented with severe aphasia and quadriplegia (NIHSS = 28). An MRI scan indicated ischemia of the vertebrobasilar system. Thirty-one hours after the onset of these symptoms, a thrombectomy was performed. After one month, the patient could move her head and the proximal part of her limbs but remained confined to bed (NIHSS = 13).

Conclusion

The current case illustrates the benefit of late mechanical thrombectomy for a posterior cerebral circulation infarct. Although there was a delay in treatment, partial recovery ensued.

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

Background and purpose

Prompt recanalization of cerebral arteries in patients diagnosed with acute ischemic stroke is known to be associated with a better clinical outcome. The aim of this study was to present our initial experience regarding the efficacy and safety of the Solitaire FR as a revascularization device.

Methods

56 consecutive patients presenting with acute ischemic stroke underwent intra-arterial therapy using the Solitaire FR revascularization device. Immediate angiographic results and early clinical outcomes are presented.

Results

Solitaire FR was successful in achieving recanalization in 50 out of 56 patients (89%) with a final Thrombolysis in Cerebral Infarction score ≥2b. Five out of 56 patients had procedure related complications: two asymptomatic subarachnoid hemorrhages, two thromboembolic events and one symptomatic intracranial hemorrhage (PH2). Thirty patients (53.5%) demonstrated at discharge a National Institutes of Health Stroke Scale Score of ≤1 or an improvement of at least 10 points from baseline, and 26 patients (46%) had a modified Rankin Score ≤2.

Conclusions

Solitaire FR is successful in achieving a high rate of arterial recanalization with a low complication rate. The Solitaire FR is a promising thrombectomy tool with a high degree of effectiveness, safety and ease of use.

Bail-out intracranial stenting with Solitaire AB device after unsuccessful thrombectomy in acute ischemic stroke of anterior circulation

BACKGROUND

Recent trials established the efficacy of mechanical stent-retriever thrombectomy for treatment of stroke patients with large vessel occlusion (LVO) in the anterior circulation. However, stent-retriever thrombectomy may not accomplish successful recanalization in all patients. The aim of this study is to report the role of bail-out permanent stenting after failure of mechanical thrombectomy.

METHODS

Among 430 patients included in a prospectively maintained database, we analysed 325 cases of anterior circulation LVO. Mechanical thrombectomy (mTICI 2b-3) was effective in 213/325 (65%) and failed in 112/325 (35%). Bail-out intracranial stenting was performed in 17/325 (5.2%) patients. In all cases a fully retrievable detachable stent was used (Solitaire AB, Medtronic).

RESULTS

No intraprocedural technical complications occurred. Successful reperfusion (mTICI 2b/3) was achieved in 12/17 patients (70.6%). Three (17.6%) patients died: one extensive infarction in the internal carotid artery territory, one large intracerebral haemorrhage, and one massive pulmonary embolism. Haemorrhagic conversion, both symptomatic and asymptomatic, occurred in 2/17 (11.7%). Good clinical outcome (mRS 0-2) at 3-months was achieved in 41.2% of patients.

CONCLUSION

Bail-out intracranial stenting after unsuccessful thrombectomy is technically feasible and the associated haemorrhagic risk seems acceptable in selected patients. We suggest that bail-out intracranial stenting, is safe and effective in selected patients with LVO stroke who failed to respond to thrombectomy.

Feasibility of Permanent Stenting with Solitaire FR as a Rescue Treatment for the Reperfusion of Acute Intracranial Artery Occlusion

BACKGROUND AND PURPOSE

The Solitaire FR can be used not only as a tool for mechanical thrombectomy but also as a detachable permanent stent. Our aim was to assess the feasibility and safety of permanent stent placement with the Solitaire FR compared with other self-expanding stents for intracranial artery recanalization for acute ischemic stroke.

MATERIALS AND METHODS

From January 2011 through January 2016, we retrospectively selected 2979 patients with acute ischemic stroke. Among them, 27 patients who underwent permanent stent placement (13 patients with the Solitaire FR [Solitaire group] and 14 patients with other self-expanding stents [other stent group]) were enrolled. The postprocedural modified TICI grade and angiographic and clinical outcomes were assessed. The safety and efficacy of permanent stent placement of the Solitaire FR for acute large-artery occlusion were evaluated.

RESULTS

Stent placement was successful in all cases. Modified TICI 2b-3 reperfusion was noted in 84.6% of the Solitaire group and in 78.6% of the other stent group. Procedural time was significantly shorter in the Solitaire group than in the other stent group (P = .022). Shorter procedural time was correlated with favorable outcome (ρ = 0.46, P = .035). No significant differences were found in the modified TICI grade, NIHSS score, mRS, and hemorrhagic transformation rate between the 2 groups. The acute in-stent thrombosis rate at discharge was significantly lower when a glycoprotein IIb/IIIa inhibitor was injected during the procedure (P = .013).

CONCLUSIONS

Permanent stent placement with the Solitaire FR compared with other self-expanding stents appears to be feasible and safe as a rescue tool for refractory intra-arterial therapy.

The golden 35 min of stroke intervention with ADAPT: effect of thrombectomy procedural time in acute ischemic stroke on outcome

Introduction

In acute ischemic stroke (AIS), extending mechanical thrombectomy procedural times beyond 60 min has previously been associated with an increased complication rate and poorer outcomes.

Objective

After improvements in thrombectomy methods, to reassess whether this relationship holds true with a more contemporary thrombectomy approach: a direct aspiration first pass technique (ADAPT).

Methods

We retrospectively studied a database of patients with AIS who underwent ADAPT thrombectomy for large vessel occlusions. Patients were dichotomized into two groups: ‘early recan’, in which recanalization (recan) was achieved in ≤35 min, and ‘late recan’, in which procedures extended beyond 35 min.

Results

197 patients (47.7% women, mean age 66.3 years) were identified. We determined that after 35 min, a poor outcome was more likely than a good (modified Rankin Scale (mRS) score 0–2) outcome. The baseline National Institutes of Health Stroke Scale (NIHSS) score was similar between ‘early recan’ (n=122) (14.7±6.9) and ‘late recan’ patients (n=75) (15.9±7.2). Among ‘early recan’ patients, recanalization was achieved in 17.8±8.8 min compared with 70±39.8 min in ‘late recan’ patients. The likelihood of achieving a good outcome was higher in the ‘early recan’ group (65.2%) than in the ‘late recan’ group (38.2%; p<0.001). Patients in the ‘late recan’ group had a higher likelihood of postprocedural hemorrhage, specifically parenchymal hematoma type 2, than those in the ‘early recan’ group. Logistic regression analysis showed that baseline NIHSS, recanalization time, and atrial fibrillation had a significant impact on 90-day outcomes.

Conclusions

Our findings suggest that extending ADAPT thrombectomy procedure times beyond 35 min increases the likelihood of complications such as intracerebral hemorrhage while reducing the likelihood of a good outcome.

History, Evolution, and Importance of Emergency Endovascular Treatment of Acute Ischemic Stroke

More than 800,000 people in North America suffer a stroke each year, with ischemic stroke making up the majority of these cases. The outcomes of ischemic stroke range from complete functional and cognitive recovery to severe disability and death; outcome is strongly associated with timely reperfusion treatment. Historically, ischemic stroke has been treated with intravenous thrombolytic agents with moderate success. However, five recently published positive trials have established the efficacy of endovascular treatment in acute ischemic stroke. In this review, we will discuss the history of stroke treatments moving from various intravenous thrombolytic drugs to intra-arterial thrombolysis, early mechanical thrombectomy devices, and finally modern endovascular devices. Early endovascular therapy failures, recent successes, and implications for current ischemic stroke management and future research directions are discussed.

What is the Role for Intra-Arterial Therapy in Acute Stroke Intervention?

Intravenous recombinant tissue plasminogen activator continues to be first-line therapy for patients with acute ischemic stroke presenting within the appropriate time window, but one potential limitation is the low rate of recanalization in the setting of large artery occlusions. Intra-arterial (IA) treatment is effective for emergency revascularization of proximal intracranial arterial occlusions, but proof of benefit has been lacking until recently. Our goal is to outline the history of endovascular therapy and review both IA thrombolysis and mechanical interventions. In addition, we will discuss the impact of important trials such as the Third Interventional Management of Stroke (IMS3) trial, and the more recent trials Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands (MR CLEAN), Endovascular Treatment for Small Core and Proximal Occlusion Ischemic Stroke (ESCAPE), Extending the Time for Thrombolysis in Emergency Neurological Deficits-Intra-Arterial (EXTEND-IA), and Solitaire With the Intention for Thrombectomy as Primary Endovascular Treatment (SWIFT PRIME) on acute stroke management and the implications for the practicing neurohospitalist.

State-of-the-art endovascular treatment of acute ischemic stroke

Stroke is the third leading cause of death in the USA. An estimated 795,000 new or recurrent stroke events occur annually, mostly ischemic in nature. Arterial recanalization and subsequent reperfusion performed shortly after symptom onset can help to restore brain function in acute ischemic stroke (AIS). The only treatment currently approved by the United States Food and Drug Administration is intravenous tissue plasminogen activator, administered within 4.5 h of symptom onset. However, this short window often precludes effective intervention. Mechanical neurothrombectomy devices offer many potential advantages over pharmacologic thrombolysis, including more rapid achievement of recanalization, enhanced efficacy in treating large-vessel occlusions, and a potentially lower risk of hemorrhagic events. The goal of this chapter is to describe the state-of-the-art neurothrombectomy devices and stenting techniques for endovascular treatment of acute ischemic stroke, as well as to highlight recent advances in reperfusion therapies. Ongoing clinical trials, some with randomized, controlled designs, are included.

Complications of the endovascular management of acute ischemic stroke

Acute ischemic stroke is a significant source of morbidity and mortality across the globe. Currently, the only US Food and Drug Administration approved medical treatment of acute ischemic stroke is intravascular (IV) alteplase. While IV thrombolysis has been shown to decrease morbidity and mortality from acute ischemic stroke, it is limited in both its efficacy in certain types of stroke, as well as in its generalizability. It has been shown that time to revascularization is one of the most important predictors of outcomes in acute ischemic stroke, and thus clinicians have turned to endovascular options in efforts to improve outcomes from stroke. Direct intra-arterial thrombolysis was one of the first of such efforts to improve efficacy rates and increase the timeline for thrombolytic therapy. More recently, investigators and clinicians have turned to newer endovascular options in attempts to further improve recanalization rates. Many different endovascular techniques have been employed and are growing exponentially in use. Examples include stenting, as well as mechanical thrombectomy with both older-generation devices and newer stent retrieval technology. While the majority of the literature focuses on the effectiveness of different techniques, such as recanalization rates and major overall outcomes such as death and disability, there is very little literature on the complications of the different techniques. The purpose of this article is to review the different forms of endovascular treatment of acute ischemic stroke and their associated complications.

Development of the Trevo ProVue Retriever for intracranial clot removal in acute ischemic stroke

It is estimated that 15 million people worldwide have a stroke each year. Of the estimated 795,000 strokes that occur in the United States annually, the majority are ischemic strokes resulting from an obstruction within a vessel supplying blood to the brain. The treatment goal for these patients is to restore blood flow as quickly as possible. Increasingly, endovascular treatments that interact directly with the clot are being pursued as options. Receiving U.S. Food and Drug Administration clearance in 2012, the Trevo® Retriever is a stent-like structure to be deployed at the site of an occlusion to allow the occluding thrombus to integrate into the device for subsequent removal and restoration of blood flow. The subsequent generation of the device, the ProVue Retriever, is fully radiopaque and designed to provide physicians with maximal information about the interaction of the device with the clot, providing enhanced feedback during the procedure. In this brief historical review, the development pathway, clinical experience, and future directions of the Trevo devices are summarized.

Endovascular stroke therapy

BACKGROUND

Following 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.

SUMMARY

Initial 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.

Endovascular treatment of acute ischemic stroke

Early recanalization of the occluded artery leads to better clinical outcomes in patients with acute ischemic stroke (AIS) through protection of the time-sensitive penumbra. Intravenous administration of pharmacologic thrombolytic agents has been a standard treatment for AIS. To get better rates of recanalization, enhance the time window, and diminish the possibility of intracranial hemorrhage, endovascular thrombectomy was launched, with first authorization of the Merci clot retriever, a corkscrew-like apparatus, followed by approval of the Penumbra thromboaspiration system. Both devices lead to a high rate of recanalization. On the other hand, time to recanalization was on an average of 45 minutes, with most of the patients attaining only partial recanalization. More lately, retrievable stents have shown promise in decreasing the time to recanalization, and attaining a superior rate of complete clot resolution. The retrievable stent can be released within the clot to engage it within the struts of the stent, and afterwards it is taken back by pulling it under flow arrest. Neurointerventional techniques have a persistently ever-increasing and stimulating role in the management of AIS, as indicated by the advent of several important techniques. Stent retrievers have the capability to be ascertained as the most important approach to endovascular stroke treatment.

Proximal to distal approach in the treatment of tandem occlusions causing an acute stroke

INTRODUCTION

A tandem occlusion is a rare presentation of acute stroke that involves an occlusion of the internal carotid artery at the bifurcation with an intracranial middle cerebral artery occlusion. This study describes the experience at our institution in treating tandem occlusions with a proximal to distal approach in the acute stroke setting.

METHODS

A retrospective review of acute strokes caused by tandem occlusions requiring thrombectomy were performed.

RESULTS

16 cases were identified with a mean National Institutes of Health Stroke Scale score at presentation of 13.1 ± 3.9. The proximal occlusion was crossed initially with a microwire in all cases. All carotid occlusions were treated with stenting, and intracranial vessel thrombectomy was performed with a variety of devices. Procedure related complications occurred in two (12.5%) patients. Eight patients (50%) achieved a good outcome (modified Rankin Scale score of 0-2).

CONCLUSIONS

A tandem occlusion of the carotid artery at the bifurcation with a concomitant intracranial occlusion is a relatively rare and complex presentation of acute stroke. We have found that addressing the proximal lesion first and covering it with a stent prior to performing distal thrombectomy appears to be a safe and effective option in the treatment algorithm.

Evolution of thrombectomy approaches and devices for acute stroke: a technical review

While intravenous administration of tissue plasminogen activator (tPA) remains the only FDA-approved treatment modality for acute ischemic stroke, many patients do not meet the criteria for intravenous tPA and are offered intra-arterial therapy. Rapid advances in devices and approaches have marked the evolution of thrombectomy over the past decade from rudimentary mechanical disruption, followed by intra-arterial thrombolytic infusions to increasingly effective thrombectomy devices. We review the critical advancements in thrombectomy technique that have evolved and the key anatomic and technical challenges they address, from first-generation Merci retrieval systems to second-generation Penumbra aspiration systems and third-generation stent retrievers, as well as nuances of their uses to maximize their effectiveness. We also highlight more recent advances that offer patients hope for more expedient vessel recanalization.

Evaluation of the Solitaire system in a canine arterial thromboembolic occlusion model: is it safe for the endothelium?

The Solitaire system has recently been increasingly used for acute stroke treatment in which the endothelial safety immediately after its use has not been evaluated. This study was performed to evaluate the endothelial status when using a Solitaire system in a canine arterial occlusion model. Thromboembolic occlusion of both internal maxillary arteries was achieved in five mongrel dogs. In each animal, the Solitaire system (ev3, Irvine, CA, USA) was used for primary thrombectomy on the right side and for temporary stenting on the left side. Efficacy was assessed by comparing the recanalization rates, and safety was assessed using angiographic and microscopic assessments. Endothelial injuries were evaluated with light microscopy (LM) and scanning electron microscopy (SEM). Successful revascularizations were observed following primary thrombectomy in all five animals (100%) and after temporary stenting in two (40%). There was no incidence of vasospasm or vessel perforation in either group. Distal migration of the clot occurred in two animals that underwent primary thrombectomy. Endothelial injury was seen after primary thrombectomy in two animals (40%) and after temporary stenting in one (20%). The lesions presented as defects of the internal elastic lamina on LM and denudation of the wavy endothelial surface on SEM. During mechanical thrombectomy, the Solitaire system can cause endothelial injury both in primary thrombectomy and temporary stenting. Primary thrombectomy is likely to have a higher recanalization rate with increased endothelial injury.

The exact science of stroke thrombolysis and the quiet art of patient selection

The science of metric-based patient stratification for intravenous thrombolysis, revolutionized by the landmark National Institute of Neurological Disorders and Stroke trial, has transformed acute ischaemic stroke therapy. Recanalization of an occluded artery produces tissue reperfusion that unequivocally improves outcome and function in patients with acute ischaemic stroke. Recanalization can be achieved mainly through intravenous thrombolysis, but other methods such as intra-arterial thrombolysis or mechanical thrombectomy can also be employed. Strict guidelines preclude many patients from being treated by intravenous thrombolysis due to the associated risks. The quiet art of informed patient selection by careful assessment of patient baseline factors and brain imaging could increase the number of eligible patients receiving intravenous thrombolysis. Outside of the existing eligibility criteria, patients may fall into therapeutic 'grey areas' and should be evaluated on a case by case basis. Important factors to consider include time of onset, age, and baseline blood glucose, blood pressure, stroke severity (as measured by National Institutes of Health Stroke Scale) and computer tomography changes (as measured by Alberta Stroke Programme Early Computed Tomography Score). Patients with traditional contraindications such as wake-up stroke, malignancy or dementia may have the potential to receive benefit from intravenous thrombolysis if they have favourable predictors of outcome from both clinical and imaging criteria. A proportion of patients experience complications or do not respond to intravenous thrombolysis. In these patients, other endovascular therapies or a combination of both may be used to provide benefit. Although an evidence-based approach to intravenous thrombolysis for acute ischaemic stroke is pivotal, it is imperative to examine those who might benefit outside of protocol-driven practice.

The Limitations of Thrombectomy with Solitaire™ AB as First-line Treatment in Acute Ischemic Stroke: A Single Center Experience

Objective

A self-expanding retrievable intracranial stent, such as Solitaire AB, is useful for mechanical thrombectomy, producing novel results in the treatment of acute ischemic stroke. On the other hand, difficult situations can arise after a thrombectomy when using as in first-line treatment.

Methods

This was a retrospective, single-center study of 23 patients with an acute ischemic stroke attributable to a large artery occlusion within the first eight hours from symptom onset. The occlusion sites were the T segment in five patients, proximal middle cerebral artery in six patients, distal middle cerebral artery in three patients, vertebral and/or basilar artery in five patients, proximal internal cerebral artery in one patient and tandem in three patients. All patients underwent a mechanical thrombectomy using the Solitaire™ stent system as the first-line treatment but required additional procedures due to the unsatisfactory results of a thrombectomy.

Results

Only six patients achieved complete recanalization by a thrombectomy using the Solitaire. Permanent stent deployment after the thrombectomy was performed in ten patients. Stent and balloon angioplasty was performed after a stent-based thrombectomy in six patients. Balloon angioplasty after thrombectomy was performed in one patient.

Conclusion

Mechanical thrombectomy with the Solitaire™ stent as a first-line treatment can produce unfortunate results that will require additional procedures.

Mechanical thrombectomy using a solitaire stent in acute ischemic stroke; initial experience in 40 patients

OBJECTIVE

This study was conducted in order to demonstrate the initial experience of the Solitaire AB stent in mechanical intracranial thrombectomy.

METHODS

We conducted a retrospective review of 40 consecutive patients who underwent intra-arterial Solitaire AB stent thrombectomy for treatment of acute ischemic strokes between October 2010 and November 2011. Demographic, clinical, and radiological presentations and outcomes were studied.

RESULTS

Twenty six men and 14 women with a mean initial National Institutes of Health Stroke Scale (NIHSS) score of 14.1 (range, 8-26) and a mean age of 65.4 (range, 32-89) years were included in this study. Occlusion sites were as follows: internal carotid artery (n = 11), middle cerebral artery M1 (n = 22), M2 (n = 5), and basilar artery (n = 2). Successful revascularization was achieved in 36 (90%) patients. The mean NIHSS score was 11.6 (range, 1-23) at 24 hours after the procedure, and 42.5% of patients showed a modified Rankin scale score of ≤ 2 at 90 days. New occlusion by migrated emboli was observed in one (2.5%) case. Post-procedural intracerebral hemorrhage occurred in only one case (2.5%), with an all-cause mortality of two (5%).

CONCLUSION

The Solitaire AB device is a relatively safe and effective tool for use in performance of mechanical thrombectomy in patients with acute ischemic stroke.

Beyond the time window of intravenous thrombolysis: standing by or by stenting?

Intravenous administration of tissue plasminogen activator within 4.5 h of symptom onset is presently the 'golden rule' for treating acute ischemic stroke. However, many patients miss the time window and others reject this treatment due to a long list of contraindications. Mechanical embolectomy has recently progressed as a potential alternative for treating patients beyond the time window for IV thrombolysis. In this paper, recent progress in mechanical embolectomy, angioplasty, and stenting in acute stroke is reviewed. Despite worries concerning the long-term clinical outcomes and increased risk of intracranial hemorrhage, favorable clinical outcomes may be achieved after mechanical embolectomy in carefully selected patients even 4.5 h after stroke onset. Potential steps should be prepared and attempted in these patients whose opportunity for recovery will elapse in a flash.

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.

Balloon-expandable stent placement in patients with immediate reocclusion after initial successful thrombolysis of acute middle cerebral arterial obstruction

We present the results of our approach for treating 12 consecutive cases of acute middle cerebral artery (MCA) stroke by performing balloon-expandable stent (BES) placement after immediate reocclusion due to the underlying stenosis after intra-arterial thrombolysis (IAT). We retrospectively reviewed the clinical outcomes of 12 patients with acute MCA stroke who underwent recanalization by BES placement in an underlying stenosis after IAT. The time to treatment, urokinase dose, duration of the procedure, recanalization rates and symptomatic hemorrhage were analyzed. Clinical outcome measures were assessed on admission and at discharge (the National Institutes of Health stroke scores [NIHSS]) as well as three months after treatment (modified Rankin scales [mRS]). The median NIHSS score on admission was 8.6. Four patients received IV rtPA. The median time from symptom onset to IAT was 236 minutes and the median duration of IAT was 62 minutes. The median dose of urokinase was 140,000 units. Initial recanalization after stent deployment (thrombolysis in cerebral ischemia attack grade of II or III) was achieved in all patients. Two patients died in the hospital due to aspiration pneumonia during medical management. In two patients, in-stent reocclusion occurred within 48 hours after stent deployment. At discharge, the median NIHSS score in ten patients (including the patients with reobstruction) was 2.4. The three-month outcome was excellent (mRS, 0-1) in eight patients. In this study, BES deployment was safe and effective in patients with an immediately reoccluded MCA after successful IAT.

Safety and efficacy of mechanical thrombectomy with solitaire stent retrieval for acute ischemic stroke: a systematic review

Purpose

In recent years, mechanical thrombectomy using Solitaire stent retrieval has been tried for treating acute ischemic stroke with a large artery occlusion. We systematically reviewed published articles to appraise the evidence that supports the safety and efficacy of the mechanical thrombectomy in acute strokes with Solitaire stent.

Materials and Methods

Systematic searches using Medline and Scopus were performed for studies evaluating mechanical thrombectomy using a Solitaire stent in acute ischemic stroke. Articles were included if they were published since 2008, contained at least 5 subjects, and provided clinical results.

Results

Thirteen articles (262 cases) were included in this review. The mean time of the procedures ranged from 37 to 95.6 minutes in 10 studies. The success of recanalization was achieved in 89.7% and the recanalization rate varied from 66.7% to 100% in all 13 studies. The overall rates of the symptomatic hemorrhagic complications and mortality were 6.8% and 11.1%, respectively. A favorable outcome of mRS 2 or under was 47.3%. Procedure-induced complications developed in 3.4%.

Conclusion

The present review suggested that mechanical thrombectomy using a Solitaire stent in acute ischemic stroke was effective in recanalizing the occluded artery. The rate of procedural complications was small.

Recanalization with Wingspan stent for acute middle cerebral artery occlusion in failure or contraindication to intravenous thrombolysis: a feasibility study

BACKGROUND AND PURPOSE

Recanalization with the Wingspan stent, which can be deployed rapidly and safely, is an option for treating acute ischemic stroke when intravenous thrombolysis has failed or is contraindicated. This study was performed to evaluate feasibility, efficacy, and safety of recanalization for acute middle cerebral artery occlusion using the Wingspan stent.

MATERIALS AND METHODS

We collected 10 patients with acute MCA occlusion in whom recanalization was not achieved with a standard intravenous thrombolysis, or who were ineligible for intravenous thrombolysis, or who presented after 3 hours of symptom onset and in whom the stent placement could be completed within 8 hours from symptom onset. We analyzed angiographic and clinical results.

RESULTS

Successful recanalization with the Wingspan stent was achieved in all patients. The mean NIHSS score on admission was 12.7 points (range 4-21). The occlusion sites were located in the 1st segment (n = 7; 2 left, 5 right) and 2nd segment (n = 3, all right) of the MCA. The mean time interval from stroke symptom onset to stent placement was 344.8 ± 76.3 minutes. No intracranial hemorrhage, vessel perforations, or dissections occurred in any patient. Nine patients improved on the NIHSS at 7 days. One patient did not have a change in the NIHSS score, even though the occluded artery was completely recanalized. At 7 days, the NIHSS score of all patients was 4.4 ± 4.7 (median 4, range 0-13). At discharge, an mRS of ≤ 3 was achieved in all patients and an mRS of ≤ 2 was achieved in 7 patients (70%).

CONCLUSIONS

This small case series demonstrates the feasibility of using the Wingspan stent safely and effectively for MCA occlusions when standard treatments are ineffective or not available.

Multimodal reperfusion therapy for large hemispheric infarcts in octogenarians: is good outcome a realistic goal?

BACKGROUND AND PURPOSE

MMRT may be beneficial in a subset of patients with large hemispheric stroke who cannot be treated with systemic thrombolysis. Because most previous studies only included relatively young patients, the outcome of very old patients given MMRT remains unknown.

MATERIALS AND METHODS

Consecutive patients with large hemispheric stroke treated with MMRT and admitted to intensive care were included. We compared neurologic and functional outcomes between patients younger and older than 80 years.

RESULTS

We included 14 patients older than 80 years and compared them with 66 patients who were younger than 80. Cerebrovascular risk factor profile, admission NIHSS scores, stroke etiology and pathogenesis, and procedure-related variables did not differ between the groups except for a higher prevalence of smoking in younger patients. Excellent target vessel recanalization (Thrombolysis in Myocardial Infarction score of 3) and good outcome at 90 days (modified Rankin Score ≤ 2) were more common in younger patients (45% versus 14%, P = .047, and 41% versus 0%, P = .008, respectively). In contrast, mortality rates were higher in octogenarians (43% versus 17%, respectively).

CONCLUSIONS

In this study, very old patients had higher chances of mortality and a very low probability of achieving functional independence even after MMRT. Further prospective studies are needed to examine the futility of MMRT in the very old.

Intracranial stents for treatment of acute ischemic stroke: evolution and current status

BACKGROUND

Intravascular stents have been applied to treat a variety of pathophysiologic conditions. With advances in stent design and delivery, stenting has become a viable treatment option in neurovascular disease. Recently, intracranial arterial stenting has received increasing interest as a modality to rapidly and effectively recanalize affected vessels in the setting of acute ischemic stroke.

METHODS

To examine the potential of stenting procedures for stroke, we compiled and analyzed relevant experimental and clinical studies in the available databases.

RESULTS

Our resulting discussion covers the brief history of stents, from their initial inception in the 1960s, to the developments of interventional cardiology, and finally to the treatment of acute occlusions of the neurovasculature. We also detail technological advances that have improved stent delivery to intracranial arteries and review the several clinical studies that feature stenting for the treatment of acute ischemic stroke.

CONCLUSION

Numerous clinical studies have revealed that stents are a quick and efficacious endovascular tool for acute ischemic stroke treatment. It appears likely that issues regarding design, safety, and feasibility of stent-based devices will experience further improvement and refinement, and from fruitful criticism of existing technologies and techniques, along with lessons from past mistakes, will arise safer and more effective devices.

Midterm clinical and angiographic follow-up for the first Food and Drug Administration-approved prospective, Single-Arm Trial of Primary Stenting for Stroke: SARIS (Stent-Assisted Recanalization for Acute Ischemic Stroke)

BACKGROUND

Although early data demonstrate encouraging angiographic results following intracranial stent deployment for acute ischemic stroke, longer-term follow-up is necessary to evaluate the clinical outcomes, as well as the durability of angiographic results.

OBJECTIVE

We report 6-month clinical and radiologic follow-up data of the 20 patients prospectively enrolled in the Stent-Assisted Recanalization in acute Ischemic Stroke (SARIS) trial.

METHODS

Twenty patients were prospectively enrolled to receive self-expanding intra-arterial stents as first-line therapy for acute ischemic stroke treatment. Patients were scheduled for follow-up 6-months after treatment for clinical evaluation (modified Rankin Scale [mRS] score obtained by a trained certified research nurse/nurse practitioner) and repeat cerebral angiography. Angiographic interpretation was performed by an independent adjudicator.

RESULTS

At 6 months, the mRS score was ≤3 in 60% of patients (n = 12) and was ≤2 in 55% of patients (n = 11). Mortality at the 6-month follow-up was 35% (n = 7). Follow-up angiography was performed for 85% (11 of 13) of surviving patients. All patients undergoing angiographic follow-up demonstrated Thrombolysis in Myocardial Infarction 3 flow on digital subtraction angiography or stent patency on computed tomographic angiography. None of the patients demonstrated evidence of in-stent stenosis (≥50% vessel narrowing).

CONCLUSION

The midterm angiographic and clinical results following intracranial stent deployment for acute ischemic stroke are encouraging. Further study of primary stent-for-stroke treatment is warranted.

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.

Stenting in the treatment of acute ischemic stroke: literature review

Recanalization of acute large artery occlusions is a strong predictor of good outcome. The development of thrombectomy devices resulted in a significant improvement in recanalization rates compared to thrombolytics alone. However, clinical trials and registries with these thrombectomy devices in acute ischemic stroke (AIS) have shown recanalization rates in the range of 40-81%. The last decade has seen the development of nickel titanium self-expandable stents (SES). These stents, in contrast to balloon-mounted stents, allow better navigability and deployment in tortuous vessels and therefore are optimal for the cerebral circulation. SES were initially used for stent-assisted coil embolization of intracranial aneurysms and for treatment of intracranial stenosis. However, a few authors have recently reported feasibility of deployment of SES in AIS. The use of these devices yielded higher recanalization rates compared to traditional thrombectomy devices. Encouraged by these results, retrievable SES systems have been recently used in AIS. These devices offer the advantage of resheathing and retrieving of the stent even after full deployment. Some of these stents can also be detached in case permanent stent placement is needed. Retrievable SES are being used in Europe and currently tested in clinical trials in the United States. We review the recent literature in the use of stents for the treatment of AIS secondary to large vessel occlusion.

Aggressive intervention to treat a young woman with intracranial hemorrhage following unsuccessful intravenous thrombolysis for left middle cerebral artery occlusion

Stroke patients whose condition does not improve after intravenous administration of tissue plasminogen activator (tPA) may be candidates for endovascular intervention. Patients with new intracerebral hemorrhage noted during such interventions pose a difficult challenge to neurointerventionists and are often sequestered as treatment failures and deemed inappropriate for intraarterial recanalization efforts. The authors present a case in which aggressive intervention was performed despite evidence of contrast extravasation on preintervention angiography. This 37-year-old woman presented with an occlusion of the M1 segment of the left middle cerebral artery and a National Institutes of Health Stroke Scale score of 24. She received intravenous tPA without improvement. Angiography revealed M1 thrombus as well as active contrast extravasation without arterial displacement. Thromboaspiration was performed in light of her known hemorrhage with excellent recanalization. Immediate postprocedure imaging demonstrated a large insular hematoma and emergent craniectomy and hematoma evacuation were performed. At 4 months' follow-up, the patient was living at home, was ambulating, and had excellent comprehension with mild expressive aphasia. There is little peer-reviewed data in the literature to aid in the decision-making process when contrast extravasation is recognized at the time of preinterevention angiography. Continuation of mechanical endovascular stroke intervention, in light of active contrast extravasation, may be warranted in young patients with major deficits and absence of arterial displacement or delayed global filling. Further thrombolytics are not advised. In select stroke patients, continuation of a planned attempt at mechanical recanalization without the further use of thrombolytics may be warranted in light of known intracerebral hemorrhage.

Mechanical thrombectomy with a self-expanding retrievable intracranial stent (Solitaire AB): experience in 26 patients with acute cerebral artery occlusion

BACKGROUND AND PURPOSE

Patients with stroke unsuitable for IV thrombolysis may be considered for endovascular revascularization, particularly when baseline imaging suggests proximal cerebral vessel occlusion associated with minimal established infarction. This retrospective review describes the use of a self-expanding retrievable intracranial stent (Solitaire AB) for thrombectomy in acute ischemic stroke.

MATERIALS AND METHODS

Twenty-six consecutive patients with stroke treated endovascularly by using the Solitaire stent were identified, followed by detailed review of data extracted from their imaging and clinical records.

RESULTS

Recanalization (TIMI grade ≥2) was achieved with Solitaire thrombectomy as the single treatment technique in 16 patients and in combination with urokinase or the Penumbra device in 9 of the remaining 10 patients. Two patients had symptomatic intracranial hemorrhage. A favorable clinical outcome (mRS score of ≤2) was seen in 3 of 5 patients with MCA occlusion, 6 of 11 (55%) patients with ICA occlusion, and 2 of 10 patients with BA occlusion.

CONCLUSIONS

Mechanical thrombectomy by using the Solitaire stent appears to be safe and is capable of achieving a high rate of recanalization and favorable clinical outcomes in patients presenting with proximal cerebral vessel occlusion.

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

Background and purpose

Prompt recanalization of cerebral arteries in patients diagnosed with acute ischemic stroke is known to be associated with a better clinical outcome. The aim of this study was to present our initial experience regarding the efficacy and safety of the Solitaire FR as a revascularization device.

Methods

56 consecutive patients presenting with acute ischemic stroke underwent intra-arterial therapy using the Solitaire FR revascularization device. Immediate angiographic results and early clinical outcomes are presented.

Results

Solitaire FR was successful in achieving recanalization in 50 out of 56 patients (89%) with a final Thrombolysis in Cerebral Infarction score ≥2b. Five out of 56 patients had procedure related complications: two asymptomatic subarachnoid hemorrhages, two thromboembolic events and one symptomatic intracranial hemorrhage (PH2). Thirty patients (53.5%) demonstrated at discharge a National Institutes of Health Stroke Scale Score of ≤1 or an improvement of at least 10 points from baseline, and 26 patients (46%) had a modified Rankin Score ≤2.

Conclusions

Solitaire FR is successful in achieving a high rate of arterial recanalization with a low complication rate. The Solitaire FR is a promising thrombectomy tool with a high degree of effectiveness, safety and ease of use.

Delayed Endovascular Revascularization in a Patient With Progressive Neurological Deterioration From Bilateral Intracranial Vertebral Artery Occlusions: Case Report

BACKGROUND AND IMPORTANCE:

This article describes delayed endovascular revascularization in a patient with clinical and radiographic evidence of posterior circulation hemodynamic failure in the setting of intracranial occlusive lesions.

CLINICAL PRESENTATION:

A 48-year-old man presented with a 6-week history of progressive headache, nausea, and ataxia. Bilateral intracranial vertebral artery occlusions and a left posterior inferior cerebellar artery stroke were diagnosed, and the patient began warfarin therapy. Despite these measures, the patient developed dense lower cranial neuropathies, including severe dysarthria, decreased left-sided hearing acuity, and left facial droop. He presented at this point for endovascular evaluation. The patient underwent successful revascularization with intravascular Wingspan stents (Boston Scientific, Natick, Massachusetts) in a delayed fashion (approximately 6 weeks after his initial stroke presentation). His neurological syndrome stabilized and began to improve slowly.

CONCLUSION:

Patients with arterial occlusion should be evaluated acutely for potential revascularization. In the posterior circulation, clinical progression may supplant physiological imaging in the assessment of hemodynamic collapse. A subpopulation of patients will present with progressive deficits distinct from extracranial manifestations of vertebrobasilar insufficiency; these patients should be considered for delayed revascularization.

Direct endovascular recanalization of chronic carotid occlusion: should we do it? Case report

BACKGROUND AND IMPORTANCE

Patients with chronic carotid artery occlusion face a significant risk of stroke. It is believed that treatment is indicated if medical therapy fails or even as prophylaxis in high-risk patients. Direct surgical repair with carotid endarterectomy has a considerable failure rate and significant associated risks. Indirect repair with an extracranial-to-intracranial bypass has become the mainstay of surgical treatment. In this case study, the authors assess the feasibility of direct endovascular recanalization in the setting of chronic carotid occlusion, and discuss technical nuances and indications in comparison with the world literature and alternative options.

CLINICAL PRESENTATION

Two patients presented with symptomatic, chronic, complete occlusion of the proximal carotid artery. The duration of documented occlusion exceeded 3 years in one patient and 6 months in the other.

METHODS

Endovascular recanalization was attempted using extracranial and intracranial stenting with proximal protection (flow arrest/reversal). Both patients had an excellent radiographic result, improving from Thrombolysis in Cerebral Infarction (TICI) grade 0 (no perfusion) to grade 3 (complete perfusion). The first patient's clinical symptoms resolved. The second patient remained unchanged with a mild facial droop.

CONCLUSION

These preliminary results show potential for the endovascular management of this complicated disease. Long-term results and more data will determine the ultimate place of endovascular recanalization for symptomatic chronic carotid occlusion among other therapies.

Treatment of acute ischemic stroke: feasibility of primary or secondary use of a self-expanding stent (Neuroform) during local intra-arterial thrombolysis

INTRODUCTION

We evaluated the feasibility of employing a self-expanding stent (Neuroform) in treatment of acute cerebral ischemia and compared the results of primary and secondary stenting.

METHODS

We analyzed the treatment results of 14 acute ischemic stroke patients (11 men and three women; median age, 65 years) who were treated with Neuroform stents. Seven patients received stent placement for primary recanalization and a further seven for secondary recanalization. We performed between-group comparisons of all of overall procedure duration, recanalization rate immediately after stenting, need for additional measures after stenting, final recanalization rate, occurrence of hemorrhagic transformation, early re-occlusion rate after 24 h, and 3-month functional recovery rate (mRS ≤2).

RESULTS

The median interval from femoral puncture to stent placement was 61.5 min and was significantly shorter in the primary than in the secondary group (55 vs. 95 min, p = 0.004). The recanalization rate immediately after stenting was 42.9% and was greater in the primary than in the secondary group (71.4% vs. 14.3%, p = 0.1). Thirteen patients required various additional therapeutic measures. The final recanalization rate was 78.6%, attributable to improvements in the recanalization rate of the secondary group (71.4% vs. 85.7%). Early hemorrhagic transformation was noted in four patients, but only one patient became symptomatic (symptomatic hemorrhage, 7.1%). Good functional recovery was noted in eight patients (57.1%).

CONCLUSION

Placement of a self-expanding stent during endovascular recanalization of acute ischemic stroke was both feasible and safe. Primary use of this method may enhance early recanalization.