Transcatheter snare removal of acute middle cerebral artery thromboembolism: technical case report

Republished: Monorail microsnare retrieval of cardiac microcatheter tip embolised to the middle cerebral artery after attempted cardiac ablation procedure

We present a case of a 52-year-old man with previous mitral valve replacement who presented to an outside hospital for planned cardiac ablation for atrial fibrillation. During the procedure, while advancing the microcatheter across the mitral valve, the microcatheter was sheared embolising into the right middle cerebral artery. This retained cardiac microcatheter tip was successfully retrieved with the monorail microsnare technique. The patient made a complete recovery without any neurological deficits or evidence of infarct on follow-up imaging.

Monorail microsnare retrieval of cardiac microcatheter tip embolised to the middle cerebral artery after attempted cardiac ablation procedure

We present a case of a 52-year-old man with previous mitral valve replacement who presented to an outside hospital for planned cardiac ablation for atrial fibrillation. During the procedure, while advancing the microcatheter across the mitral valve, the microcatheter was sheared embolising into the right middle cerebral artery. This retained cardiac microcatheter tip was successfully retrieved with the monorail microsnare technique. The patient made a complete recovery without any neurological deficits or evidence of infarct on follow-up imaging.

Assessing the efficacy of endovascular therapy in stroke treatments: updates from the new generation of trials

INTRODUCTION

For the past 20 years, intravenous recombinant tissue plasminogen activator (rt-PA) has been the only proven treatment for acute ischemic stroke. Large arteries such as the internal carotid artery, the middle cerebral artery and the basilar artery supply blood to large volumes of brain tissue. When occluded, these vessels may have low response rates to rt-PA resulting in devastating injury and death. Areas covered: In 2013, three trials evaluating the efficacy of mechanical thrombectomy in acute stroke were neutral, however, lessons learned from these trials resulted in a second generation of five trials in 2015 and a sixth in 2016 which all demonstrated significant benefit for select patients. Here we will review the evidence behind these new trials and. introduce new questions such as models of care, techniques of thrombectomy, the role of rt-PA, modes of anesthesia, the management of late presenting and wake up strokes among other real world challenges facing stroke medicine now that the thrombectomy is an evidence based treamtnent Expert commentary: The mechanical thrombectomy is now the new standard of care and with that comes the need to find ways to provide it to all who will benefit.

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.

Acute combined revascularization in acute ischemic stroke with intracranial arterial occlusion: self-expanding solitaire stent during intravenous thrombolysis

PURPOSE

To investigate the safety and efficacy of the self-expanding Solitaire stent used during intravenous thrombolysis (IVT) for intracranial arterial occlusion (IAO) in acute ischemic stroke (AIS).

MATERIALS AND METHODS

Consecutive nonselected patients with AIS with IAO documented on computed tomographic angiography or magnetic resonance angiography and treated with IVT were included in this prospective study. Stent intervention was initiated and performed during administration of IVT without waiting for any clinical or radiologic signs of potential recanalization. Stroke severity was assessed by National Institutes of Health Stroke Scale (NIHSS), and 90-day clinical outcome was assessed by modified Rankin scale (mRS), with a good outcome defined as an mRS score of 0-2. Recanalization was rated by thrombolysis in cerebral infarction (TICI) scale.

RESULTS

Fifty patients (mean age, 66.8 y ± 14.6) had a baseline median NIHSS score of 18.0. Overall recanalization was achieved in 94% of patients, and complete recanalization (ie, TICI 3 flow) was achieved in 72% of patients. The mean time from stroke onset to maximal recanalization was 244.2 minutes ± 87.9, with a median of 232.5 minutes. The average number of device passes was 1.5, with a mean procedure time to maximal recanalization of 49.5 minutes ± 13.0. Symptomatic intracerebral hemorrhage occurred in 6% of patients. The median mRS score at 90 days was 1, and 60% of patients had a good outcome (ie, mRS score 0-2). The overall 3-month mortality rate was 14%.

CONCLUSIONS

Combined revascularization with the Solitaire stent during IVT appears to be safe and effective in the treatment of acute IAO.

Advances in revascularization for acute ischemic stroke treatment

Intravenous thrombolysis with recombinant tissue plasminogen activator is the established treatment for acute ischemic stroke patients presenting within 3 h after stroke onset. In a significant number of patients, however, intravenous thrombolysis with recombinant tissue plasminogen activator remains ineffective. New thrombolytic agents, such as reteplase, tenecteplase or desmoteplase, offer pharmacokinetic and dynamic advantages over recombinant tissue plasminogen activator and have been or are currently being tested for safety and efficacy in clinical trials. Endovascular revascularization is an evolving treatment option enabling mechanical clot disruption or extraction in combination with thrombolysis. Several new endovascular devices have been successfully tested for safety in acute ischemic stroke patients and are now being tested for efficacy in larger clinical trials. Continued innovation and refinement of endovascular technology and techniques is expected to increase technical success with a minimal procedure-related morbidity in the treatment of acute ischemic stroke.

Acute vertebrobasilar occlusion: current treatment strategies

Acute vertebrobasilar occlusion (VBO) remains a disease with a high mortality. Local intraarterial fibrinolysis (LIF) can reduce the mortality rate from about 90 to 60%. The combined therapy of i.v. Abciximab and i.a. rt-PA with additional PTA/stenting may improve neurological outcome and significantly reduce mortality, despite an increase of overall bleeding complications. Additional PTA/stenting is an important treatment factor in cases of atherothrombotic occlusion. In embolic occlusions, mechanical catheter devices, such as basket or snare devices or rheolytic systems, are promising therapies for the near future. This article describes diagnostic criteria and treatment factors in acute VBO. Different treatment strategies, such as i.v. and i.a. fibrinolysis, adjunctive application of GP IIb/IIIa inhibitors, PTA/stenting and mechanical embolectomy are addressed in detail.

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.

Recanalization therapy for acute ischemic stroke, part 2: mechanical intra-arterial technologies

Stroke therapy has been revolutionized in the past two decades with the widespread implementation of chemical thrombolysis for acute stroke. However, chemical thrombolysis continues to be limited in its efficacy secondary to relatively short time windows and a high associated risk of hemorrhage. In an attempt to minimize hemorrhagic complications and extend the available therapeutic window, mechanical devices designed specifically for thrombus removal, clot obliteration, and arterial revascularization have experienced a recent surge in development and utilization. As such, chemical thrombolytics now represent only one of many options in acute stroke therapy. These new mechanical devices have extended the potential treatment window and now provide alternatives to patients who do not respond to conventional intravenous thrombolysis. This review will discuss the development of these devices, supporting literature, and the individual strengths that each engenders towards a life-saving therapy for stroke.

Multimodal Therapy for the Treatment of Severe Ischemic Stroke Combining Endovascular Embolectomy and Stenting of Long Intracranial Artery Occlusion

Embolic occlusion of cerebral arteries is a major cause for stroke. Intravenous thrombolysis showed positive results in this condition, however even when strict criteria are used, the risk of hemorrhagic transformation is possible. Microsurgical embolectomy has been described earlier. Purpose. We performed multimodal therapy of cerebral artery occlusion. Case Report. We present a case of a 49-year-old female patient who—according to the National Institute of Health Stroke Scale (NIHSS)—was rated as 19 due to acute occlusion of the horizontal segment of the left middle cerebral artery (MCA). After failed i.v. thrombolysis, only a part of the clot could be evacuated by the endovascular approach—without restoration of blood flow. Normal patency of the left MCA was re-established after stenting. Within 72 hours, the patient had an NIHSS score of 14, with a small haematoma in the left hemisphere. Conclusion. In our case multimodal therapy combining i.v. thrombolysis, mechanical disruption of thrombus, MCA stenting and platelet function antagonists, resulted in successful recanalization of the acutely occluded left MCA.

The MERCI Retrieval System for the Management of Acute Ischaemic Stroke – The NNI Singapore Experience

Introduction: Systemic and local intra-arterial thrombolysis in patients with large vessel ischaemic stroke is hampered by poor re-canalisation rates and risk of haemorrhage. The Merci Retrieval System is an endovascular device for removal of acute intracranial thrombus. We present our initial experience using this device in conjunction with existing thrombolytic therapy already in place in our institute. Materials and Methods: Prospective data in all patients presenting with large vessel ischaemic stroke treated using the Merci Retrieval System from July 2007 to March 2009 were analysed. Selection criteria for patients were similar to the multi- Merci trial of 2008. We compared re-canalisation rate, National Institutes of Health Stroke Score (NIHSS) and modified Rankin score (mRS) outcomes to the published trial results. Results: Seventeen patients were reviewed; none suffered immediate post-procedural complications. Fifteen underwent successful thrombus retrieval but in 2 cases the device failed due to technical considerations. Sites of vascular occlusion included: ICA/ICA-‘T’ junctions 27%, middle cerebral artery 13% and vertebrobasilar artery 60%. Of the 15 patients treated by MERCI with or without adjuvant thrombolytic therapy, complete re-canalisation was achieved in 60%, partial re-canalisation in 20%, partial re-canalisation with persistent distal vessel occlusion in 6% and failure of re-canalisation in 14%. Asymptomatic haemorrhage occurred in 33% and there was 1 death (6%) from symptomatic haemorrhage. Pre-treatment median NIHSS was 17.88 and 9.5 immediately post-treatment. Median mRS at 30 days was 2.6 for patients who achieved complete re-canalisation and 4.5 in failure or partial re-canalisation with or without persistent distal vessel occlusion. Conclusion: Re-canalisation rates using the Merci Retrieval System was comparable to the multi-Merci trial. Haemorrhagic complications and safety were also found to be satisfactory. Importantly, treatment success with eventual good clinical outcome hinges strongly on the ability of the device to achieve complete re-canalisation. Key words: Acute ischaemic stroke, Mechanical revascularisation, Thrombectomy, The Merci Retrieval System

Mechanical thrombectomy with snare in patients with acute ischemic stroke

INTRODUCTION

We evaluated the efficacy and safety of thrombus extraction using a microsnare in patients with acute ischemic stroke (AIS).

METHODS

This was a prospective, observational, cohort study in which consecutive patients with AIS (<6 hours of ischemia for anterior circulation and <24 hours for posterior circulation) who had been previously excluded from intravenous tissue plasminogen activator (tPA) thrombolysis were included and followed-up for 3 months. Mechanical embolectomy with a microsnare of 2-4 mm was undertaken as the first treatment. Low-dose intraarterial thrombolysis or angioplasty was used if needed. TIMI grade and modified Rankin stroke scale (mRSS) score were used to evaluate vessel recanalization and clinical efficacy, respectively.

RESULTS

Nine patients (mean age 55 years, range 17-69 years) were included. Their basal mean NIHSS score was 16 (range 12-24). In seven out of the nine patients (77.8%) the clot was removed, giving a TIMI grade of 3 in four patients and TIMI grade 2 in three patients. Occlusion sites were: middle cerebral artery (four), basilar artery (two) and anterior cerebral artery plus middle cerebral artery (one). The mean time for recanalization from the start of the procedure was 50 min (range 50-75 min). At 3 months, the mRSS score was 0 in two patients and 3-4 in three patients (two patients died).

CONCLUSION

According to our results, the microsnare is a safe procedure for mechanical thrombectomy with a good recanalization rate. Further studies are required to determine the role of the microsnare in the treatment of AIS.

Experimental treatments for acute ischaemic stroke

Treatments for acute ischaemic stroke continue to evolve. Experimental approaches to restore cerebral perfusion include techniques to augment recanalising therapies, including combination of antiplatelet agents with intravenous thrombolysis, bridging therapy of combining intravenous with intra-arterial thrombolysis, and trials of new thrombolytic agents. Trials with MRI selection criteria are underway to expand the window of opportunity for thrombolysis. Sonothrombolysis and novel endovascular mechanical devices to retrieve or dissolve acute cerebral occlusions are being tested. Approaches to improve cerebral perfusion with other devices and induced hypertension are also being considered. Although numerous neuroprotective agents have not shown benefit, trials of hypothermia, magnesium, caffeinol, high doses of statins, and albumin are continuing. The findings of these randomised trials are anticipated to allow improved treatment of patients with acute stroke.

Merci Retriever in acute stroke treatment

The Merci Retriever is a device used for mechanical clot extraction in cerebral arteries. It obtained US FDA clearance in August 2004 for recanalization of cerebral arteries in acute stroke. Previously, intravenous recombinant tissue plasminogen activator administered within 3 h from symptom onset was the only other FDA-approved treatment in acute stroke. Stroke from large brain artery occlusion, which has the highest morbidity and mortality rate, is inefficiently treated with intravenous recombinant tissue plasminogen activator and has a high likelihood of hemorrhagic complication. In the multicenter prospective Mechanical Embolus Removal in Cerebral Ischemia trial that led to FDA clearance, the Merci Retriever achieved 48% vessel recanalization when used within 8 h of stroke onset, and resulted in lower morbidity and mortality in revascularized patients. Clinical efficacy trials are needed to determine the place of this device in the treatment of stroke patients.

Current issues in the treatment of acute posterior circulation stroke

This article presents a narrative review of the non-medical, medical and endovascular aspects of the management of acute ischaemic stroke in the posterior circulation, a potentially devastating condition with high mortality and substantial disability in many of those who survive. Optimal management requires a combination of supportive measures and specific interventions and is best delivered within a high-dependency or intensive care environment. Non-medical measures include management of physiological parameters, respiratory support where necessary and prompt treatment of complications such as the development of hydrocephalus. Deterioration in conscious state and progression of symptoms may occur some time after initial presentation and after admission to hospital; when such progression is detected, very rapid therapeutic reperfusion may be feasible. Reperfusion strategies include intravenous and intra-arterial thrombolysis (IAT) and mechanical methods to aid reperfusion, including the use of mechanical clot disruption, clot retrieval or stenting devices. The optimal reperfusion strategy, including considerations of whether to use intravenous or intra-arterial thrombolytic approaches, the use of bridging intravenous treatment prior to intra-arterial treatment, and the use of pharmacological or mechanical adjuncts to IAT is not known. However, it seems likely that the important determinant of therapeutic efficacy is the speed and safety with which reperfusion can be achieved. It may also be that the time available to achieve reperfusion is longer than in the anterior circulation.

Analysis of Thrombi Retrieved From Cerebral Arteries of Patients With Acute Ischemic Stroke

Background and Purpose— Information regarding the histological structure of thromboemboli that cause acute stroke provides insight into pathogenesis and clinical management.

Methods— This report describes the histological analysis of thromboemboli retrieved by endovascular mechanical extraction from the middle cerebral artery (MCA) and intracranial carotid artery (ICA) of 25 patients with acute ischemic stroke.

Results— The large majority (75%) of thromboemboli shared architectural features of random fibrin:platelet deposits interspersed with linear collections of nucleated cells (monocytes and neutrophils) and confined erythrocyte-rich regions. This histology was prevalent with both cardioembolic and atherosclerotic sources of embolism. “Red” clots composed uniquely of erythrocytes were uncommon and observed only with incomplete extractions, and cholesterol crystals were notably absent. The histology of thromboemboli that could not be retrieved from 29 concurrent patients may be different. No thrombus >3 mm wide caused stroke limited to the MCA, and no thrombus >5 mm wide was removed from the ICA. A mycotic embolus was successfully removed in 1 case, and a small atheroma and attached intima were removed without clinical consequence from another.

Conclusions— Thromboemboli retrieved from the MCA or intracranial ICA of patients with acute ischemic stroke have similar histological components, whether derived from cardiac or arterial sources. Embolus size determines ultimate destination, those >5 mm wide likely bypassing the cerebral vessels entirely. The fibrin:platelet pattern that dominates thromboembolic structure provides a foundation for both antiplatelet and anticoagulant treatment strategies in stroke prevention.

Self-expanding stent-assisted middle cerebral artery recanalization: technical note

INTRODUCTION

Investigation into pharmacological and mechanical means of improving recanalization rates by intraarterial therapy has led to technological development. Angiographic recanalization has been associated with improvement in clinical outcome. A clot retriever has recently joined an imperfect armamentarium for intraarterial stroke therapy. In this report, we describe successful recanalization of an acute thrombotic occlusion of the inferior division of the middle cerebral artery (MCA) achieved with a self-expanding stent.

METHODS

An 82-year-old woman with a history of coronary atherosclerosis and previous cerebellar hemorrhage presented with a National Institutes of Health Stroke Scale (NIHSS) score of 11. Perfusion computed tomography imaging showed a left MCA territory deficit. Diffusion-weighted magnetic resonance (MR) imaging revealed a small punctiform insular hyperintensity. Angiography documented occlusion of the inferior division of the left MCA (Thrombolysis in Myocardial Infarction or Thrombolysis in Cerebral Infarction, TIMI/TICI, grade 0). Intraarterial delivery of eptifibatide to the occlusion site failed to recanalize the vessel. Deployment of a self-expanding stent in the occluded segment resulted in complete revascularization of the distal vascular bed.

RESULTS

Angiography performed on the next day confirmed patency of the stented vessel segment (TIMI/TICI 3). The patient was discharged 3 days after the procedure (NIHSS 3). MR angiography obtained 3 months after the procedure documented left MCA patency.

CONCLUSION

This technique may have a role worthy of further investigation in acute stroke therapy.

Evaluation of Merci Retriever by Experimental Modeling

The Merci Retriever is the first device for mechanical embolus removal in patients with cerebral ischemia. Use of the device was evaluated using experimental models. Three stroke model systems were created: silicone embolism model with flow system, pig embolism model, and silicone-pig tortuous artery model. The series of extraction procedures (capture, retrieval, and aspiration) was examined in the models under flow control. Coagulated blood clot was adopted as embolic material, to simulate embolic stroke of the carotid or middle cerebral arteries. Retrieval of the clot was successful in only one of six trials in the silicone model of the carotid artery, as the clot easily worked free from the helical tip. Aspiration was successful in three of the six trials. Retrieval was successful in two of four trials in the middle cerebral artery and aspiration was successful in two. Retrieval was successful in all five trials in the pig embolism model, and three of five trials in the silicone-pig tortuous artery model. The Merci Retriever does not always retain the embolism, and the helix tends to distort in acute or rough lumen. Aspiration is not always successful.

Recanalization of long-lasting middle cerebral artery occlusion by a combination of surgical and interventional approaches: technical case report

OBJECTIVE AND IMPORTANCE

In strictly selected cases of middle cerebral artery (MCA) occlusion, revascularization by extracranial-intracranial (EC-IC) bypass can be considered. The interventional recanalization of the occlusion under direct surgical control has not been reported in the literature so far.

CLINICAL PRESENTATION

A 39-year-old Caucasian female patient had experienced an ischemic stroke 15 years before she came to our attention. At that time, occlusion of the right MCA was diagnosed by angiography. Her neurological deficit resolved within 6 months. Fifteen years later, the patient experienced repeated numbness of her left-sided extremities, which was refractory to medical treatment. Angiography revealed an occluded M1 segment of the MCA. Perfusion computed tomography without and after CO2 stimulation disclosed impaired cerebrovascular capacity.

INTERVENTION

The patient was scheduled for EC-IC bypass. The MCA tree was exposed, and the occluded portion was found to be 10 mm long. We then decided to reopen the vessel by balloon dilation under direct visual control. A catheter was advanced to the M1 origin, where a glidewire was passed into the vessel lumen. With only a little help from the surgeon, it was surprisingly easy to direct the glidewire through the occluded segment. At this time, flow through the M1 segment was re-established. Flow through the MCA that had occluded for 15 years was re-established.

CONCLUSION

On the basis of our experience, in nonatherosclerotic occlusions, intravascular intervention may be considered.

Multimodal Therapy for the Treatment of Severe Ischemic Stroke Combining GPIIb/IIIa Antagonists and Angioplasty After Failure of Thrombolysis

BACKGROUND AND PURPOSE

Intraarterial and intravenous thrombolysis are often ineffective for the treatment of acute ischemic stroke and are associated with a significant risk of intracranial hemorrhage (ICH). Multimodal rescue therapy combining mechanical disruption and platelet GPIIb/IIIa receptor antagonists may improve recanalization.

METHODS

Patients who did not recanalize with thrombolysis were treated with GPIIb/IIIa antagonists, angioplasty, or an embolectomy device. Treatment was individualized based on vascular anatomy, stroke mechanism, patient status, and symptom duration.

RESULTS

Twelve patients were treated within 3.8+/-2.2 hours. The mean National Institutes of Health Stroke Scale (NIHSS) score was 19.4+/-4.1. Six patients had carotid terminus occlusion, whereas 5 had middle cerebral artery and 1 had basilar artery occlusion. The average doses of intraarterial tPA and reteplase were 17.1+/-8.6 mg and 2+/-0.6 units, respectively. All patients received either an intravenous or intraarterial abciximab bolus (mean 11.8+/-5.8 mg) and heparin (mean 3278+/-1716U). Eleven were treated with angioplasty and 4 had mechanical embolectomy or stenting. Complete (8) or partial (3) recanalization was achieved in 11 cases. There was only one (8.3%) symptomatic hemorrhage. Patients had a favorable outcome at discharge (mean NIHSS 8.9+/-8.7) and 6 (50%) had an NIHSS < or =4 at discharge.

CONCLUSIONS

Multimodal rescue therapy was effective at recanalizing occluded cerebral vessels that failed thrombolysis without an excess risk of ICH.

Mechanical Embolectomy

Mechanical embolectomy in acute ischemic stroke employs the use of novel endovascular devices to revascularize occluded intracerebral arteries. Devices like the Merci Retiever and other endovascular snares, laser thrombectomy and rheolytic/obliterative microcatheters, intracranial balloon angioplasty and stenting, and intra-arterial and transcranial ultrasound-enhanced chemical thrombolysis are intended to improve tissue rescue and diminish reperfusion hemorrhage while broadening the population eligible for therapy. Patient selection with MRI- and CT-based stroke protocols can detect tissue at risk and may obviate the classic limitations of the stroke therapeutic time window. These devices are being developed and modified at a rapid pace, requiring mounting endovascular expertise, and are being used successfully alone or in conjunction with chemical thrombolysis with relative safety.

Recommendations for Comprehensive Stroke Centers

Background and Purpose— To develop recommendations for the establishment of comprehensive stroke centers capable of delivering the full spectrum of care to seriously ill patients with stroke and cerebrovascular disease. Recommendations were developed by members of the Brain Attack Coalition (BAC), which is a multidisciplinary group of members from major professional organizations involved with the care of patients with stroke and cerebrovascular disease.

Summary of Review— A comprehensive literature search was conducted from 1966 through December 2004 using Medline and Pub Med. Articles with information about clinical trials, meta-analyses, care guidelines, scientific guidelines, and other relevant clinical and research reports were examined and graded using established evidence-based medicine approaches for therapeutic and diagnostic modalities. Evidence was also obtained from a questionnaire survey sent to leaders in cerebrovascular disease. Members of BAC reviewed literature related to their field and graded the scientific evidence on the various diagnostic and treatment modalities for stroke. Input was obtained from the organizations represented by BAC. BAC met on several occasions to review each specific recommendation and reach a consensus about its importance in light of other medical, logistical, and financial factors.

Conclusions— There are a number of key areas supported by evidence-based medicine that are important for a comprehensive stroke center and its ability to deliver the wide variety of specialized care needed by patients with serious cerebrovascular disease. These areas include: (1) health care personnel with specific expertise in a number of disciplines, including neurosurgery and vascular neurology; (2) advanced neuroimaging capabilities such as MRI and various types of cerebral angiography; (3) surgical and endovascular techniques, including clipping and coiling of intracranial aneurysms, carotid endarterectomy, and intra-arterial thrombolytic therapy; and (4) other specific infrastructure and programmatic elements such as an intensive care unit and a stroke registry. Integration of these elements into a coordinated hospital-based program or system is likely to improve outcomes of patients with strokes and complex cerebrovascular disease who require the services of a comprehensive stroke center.

Catheter-Directed Intra-Arterial Abciximab Administration for Acute Thrombotic Occlusions during Neurointerventional Procedures

SUMMARY

Abciximab is one of a new class of platelet aggregation inhibitors that has to date been used mainly in the management of acute coronary ischaemic syndromes or during cardiac intervention for the prevention and treatment of acute vessel occlusion during and after angioplasty or stent placement. More recently, it has begun to play a similar role in neurointerventional work. Its administration during acute stent or vessel occlusions has usually been via systemic intravenous infusion.We describe five cases of acute vessel occlusion during neurointerventional procedures where the abciximab bolus was administered intra-arterially at or close to the site of the occlusion, with rapid complete visual dissolution of the thrombus in four cases and partial dissolution in one, resulting in two patients with no neurological deficits, one with no further neurological deterioration, one with a mild residual thumb paresis and one with a severe neurological deficit.

Endovascular treatment of acute embolism of the major cerebral arteries. The value of balloon disruption of the embolus

SUMMARY

This study evaluated: 1) the effect of recanalization on changing clinical outcome, 2) the relationship between dose of Urokinase (UK) and incidence of recanalization and intracranial haemorrhage, and 3) the efficacy and feasibility of balloon disruption (BD) in the treatment of acute cerebral embolism. Sixty-one patients with acute embolism of the major cerebral arteries treated by endovascular approaches over the past nine years were retrospectively evaluated. Among them, 30 cases were treated by BD alone or in conjunction with intra- arterial fibrinolysis in the last five years. The other 31 cases, mostly treated in the first four years, were treated with intra-arterial fibrinolysis alone and were used as controls to evaluate the efficacy of BD. Control angiography was performed just after the reperfusion procedure to evaluate the degree of recanalization. Angiographic responses were graded using modified Thrombolysis in Myocardial Infarction (TIMI) criteria. Clinical outcome was evaluated using modified Rankin Scale (mRS) score at the time of discharge. Thirty-six of the 61 patients (59.0%) achieved high-grade recanalization (TIMI grade 3). Significantly more patients attained favorable outcome (mRS score 0-1) in the high-grade recanalization group than the low-grade recanalization group (41.7% vs. 16.0%, p < 0.05). Concerning patients treated with BD, significantly more patients attained good recanalization and significantly more patients were ambulatory (mRS score 0-3) than those treated with intra-arterial fibrinolysis alone (76.7% vs. 41.9%, p < 0.01; 70.0% vs. 41.9%, p < 0.05, respectively). A significantly lower dose of UK was used, and relatively less intracranial haemorrhage was seen in patients treated with BD than those treated with intra- arterial fibrinolysis (194,000 +/- 191,000 units vs. 388,000 +/- 231,000 units, p=0.001; 16.7% vs. 38.7%, p=0.055, respectively). Concerning morbidity and mortality of BD, there was one death caused by dissection of the M2 portion of the middle cerebral artery (MCA) that happened during BD on a distally migrated embolus. Although no conclusions can be drawn from our study, a favorable outcome for acute embolism of the major cerebral arteries is expected by attaining good recanalization. In addition, BD is an effective technique that can achieve high-grade recanalization alone, or reducing the dose of fibrinolytic agent.

The acute cerebrovascular event: surgical and other interventional therapies

Over the next decade, more early and aggressive treatments will become available for acute stroke. As EPs have been forced to push their skills and knowledge significantly further with the advent of time-sensitive interventions for myocardial ischemia, a similar sophistication will undoubtedly emerge in the management of acute stroke. Certain components of the neurological examination will likely assume a new significance and, as with the renewed focus on the nature of ST segment change on the ECG in ACS, there will be new attention to early imaging findings in stroke. Although it is unclear whether the balance of future advances in treatment will come from the world of neurosurgery, neurology, or interventional radiology, the EP is relatively assured to play a central role in their implementation.

Evolution of Neuroendovascular Intervention: A Review of Advancement in Device Technology

NEUROENDOVASCULAR SURGERY IS a rapidly evolving field. Each year, numerous improvements are made in the endovascular surgeon's armamentarium. This evolution in technology, which is occurring at a dizzying pace, addresses many of the current limitations of neuroendovascular approaches. The potential to improve the outcomes of our patients is tremendous, particularly because one of the most common and most devastating neurological disorders, ischemic stroke, remains largely untreated. This article presents several of the new technologies that are currently being investigated or are under development and have the potential to lead to major advances in endovascular approaches for the treatment of intracranial and extracranial diseases.

Bivalirudin for Endovascular Intervention in Acute Ischemic Stroke: Case Report

OBJECTIVE AND IMPORTANCE

Intra-arterial thrombolysis has been demonstrated to improve recanalization and outcomes among patients with acute ischemic stroke. However, thrombolytic agents have limited effectiveness and are associated with a significant risk of bleeding. Bivalirudin is a direct thrombin inhibitor that has been demonstrated in the cardiology literature to have a more favorable efficacy and bleeding profile than other antithrombotic medications. We report the use of bivalirudin during endovascular treatment of acute stroke, when hemorrhagic complications are not uncommon.

CLINICAL PRESENTATION

A 71-year-old woman with atrial fibrillation presented with right hemiparesis and aphasia and was found to have a National Institutes of Health Stroke Scale score of 10. Computed tomographic scans revealed no evidence of intracranial hemorrhage, aneurysm, or ischemic stroke. Cerebral angiography revealed thromboembolic occlusion of the superior division of the left middle cerebral artery.

INTERVENTION

For anticoagulation, a loading dose of bivalirudin was intravenously administered before the interventional procedure, followed by continuous infusion. Attempts to remove the clot with an endovascular snare failed to induce recanalization of the vessel. Bivalirudin was then administered intra-arterially. Immediate postprocedural angiography demonstrated restoration of flow in the left middle cerebral artery. Repeat computed tomographic scans demonstrated no intracranial hemorrhage. The patient's hemiparesis and aphasia were nearly resolved and her National Institutes of Health Stroke Scale score was 2 at the time of her discharge 5 days later.

CONCLUSION

To our knowledge, this is the first report of the use of bivalirudin for treatment of acute ischemic stroke. Bivalirudin may be a useful agent for intravenous anticoagulation and intra-arterial thrombolysis in this setting.

Endovascular embolectomy of acute basilar artery occlusion

Acute basilar artery occlusion has a mortality rate approaching 90%. The authors describe a case of acute basilar artery occlusion managed successfully with endovascular embolectomy. A 31-year-old man sought treatment for confusion, dysarthria, and right-sided weakness. He soon became unresponsive and was found to have a vertebral artery dissection and an associated basilar artery embolism. The dissection was managed with endovascular stenting, and the basilar artery embolus was removed with a clot retriever at 7 hours. The patient recovered without neurologic deficit.

Local intra-arterial fibrinolysis of thromboemboli occurring during neuroendovascular procedures with recombinant tissue plasminogen activator

BACKGROUND AND PURPOSE

There is a lack of systematic data regarding local intra-arterial fibrinolysis (LIF) of thromboemboli occurring during neuroendovascular procedures with the use of recombinant tissue plasminogen activator (rtPA). We report our technique for treating LIF of intracerebral thromboemboli occurring during neuroendovascular procedures.

METHODS

Nine of 723 patients (1.2%) who underwent neuroendovascular procedures during the period from January 1997 to September 2002 suffered thromboembolic complications. These patients were treated by LIF with a maximum dose of 0.9 mg rtPA per kilogram body weight. Recanalization was categorized as successful (Thrombolysis in Myocardial Infarction [TIMI] grade 2 or 3) versus unsuccessful (TIMI grade 0 or 1), and clinical outcome was categorized as independent (Rankin Scale score 0 to 2) versus dependent or dead (Rankin Scale score 3 to 6).

RESULTS

The minimum time between thrombus detection and beginning of LIF was 10 minutes, and the maximum time was 90 minutes. Successful recanalization was achieved in 4 of 9 patients (44%). All 9 patients suffered cerebral ischemic infarctions, and none of the patients sustained intracerebral hemorrhage. Two patients (22%) died from malignant brain infarctions. Four patients (44%) remained moderately disabled, and 3 patients (33%) were severely disabled 3 months after LIF.

CONCLUSIONS

Although we used relatively high doses of rtPA, the recanalization rates and clinical outcome of LIF in our patients were not satisfactory. Strategies for the prevention of thromboemboli during neuroendovascular procedures must be improved, and novel fibrinolytic or thrombolytic techniques should be developed.

Beyond tissue plasminogen activator: mechanical intervention in acute stroke

Mechanical interventions in acute ischemic stroke promise to provide emergency physicians with tools to treat patients in whom conventional thrombolysis might be ineffective or contraindicated, including most patients with stroke who arrive at the emergency department beyond the 3-hour time window for intravenous tissue plasminogen activator. A systematic MEDLINE literature review was performed. Endovascular interventions currently in early human clinical trials include the use of lasers, ultrasonography, angioplasty, microsnares, and a variety of clot-retrieval devices. Potential advantages of these approaches include more rapid recanalization of occluded vessels, reduced or no exposure to fibrinolytic agents, and a longer treatment window. Early safety trials are promising, with serial improvements in device design to minimize trauma to cerebrovascular endothelium and accelerate vessel recanalization. The purpose of this review is to provide the emergency medicine community with an understanding of these promising and emerging approaches to acute stroke therapy.

Snare retrieval of intracranial thrombus in patients with acute stroke

Intravenous or intraarterial thrombolysis of intracranial emboli is becoming an accepted clinical treatment modality for acute ischemic stroke, but not all emboli respond to the lytic drug regimens available today. If drug therapy fails, mechanical retrieval seems warranted. Four patients whose condition was resistant to intravenous and intraarterial thrombolytic drug treatment underwent at least partial clot removal with use of a snare, and almost immediate clinical improvement was noted. A fifth patient's clot was removed before lytic drugs were administered. All five patients, who presented with a sudden onset of stroke, were evaluated by arterial angiography; then, after a failed trial of intraarterial fibrinolytic drugs, they were treated by passing a 2- or 4-mm snare through a microcatheter. The snare wire was guided around the thrombus, gently brought back toward the microcatheter-but not into it-and the entire microcatheter and snare assembly was then removed. In four of the five cases, follow-up angiography performed immediately after the retrieval showed wider distal branches than normal. Follow-up computed tomography results were abnormal in all cases, showing hyperdense material in the territory that was previously ischemic. This hyperdensity subsided within 48 hours in all but one patient who developed small parenchymal hemorrhages; however, he remained asymptomatic. The snare device offers an additional or alternative therapy until completely effective thrombolytic agents become available. Although use of a snare is not ideal, device improvements should make the retrieval less technically challenging and more effective. There is a need for improved mechanical extraction devices, especially in light of the patient improvement that occurred. This experience also suggests that immediate removal of a mature clot could reduce the total time of brain ischemia more quickly than administration of thrombolytic drugs.

Aggressive mechanical clot disruption and low-dose intra-arterial third-generation thrombolytic agent for ischemic stroke: a prospective study

OBJECTIVE

We prospectively evaluated the safety and effectiveness of aggressive mechanical disruption of clot in conjunction with intra-arterial administration of a low-dose third-generation thrombolytic agent (reteplase) to treat ischemic stroke in patients who were considered poor candidates for intravenous alteplase therapy or who failed to improve after intravenous thrombolysis. Mechanical clot disruption was used if low-dose pharmacological thrombolysis was ineffective. This strategy was adopted to increase the recanalization rate without increasing the risk of intracerebral hemorrhage.

METHODS

Patients were considered poor candidates for intravenous therapy because of severity of neurological deficits, interval from symptom onset to presentation of at least 3 hours, or recent major surgery. We administered a maximum total dose of 4 U of reteplase intra-arterially in 1-U increments via superselective catheterization. After the initial doses were administered, we performed mechanical angioplasty (for proximal occlusion) or snare manipulation (for distal occlusion) at the occlusion site if recanalization had not occurred. The remaining doses of thrombolytics were subsequently administered if required for further recanalization. Angiographic responses were graded using modified Thrombolysis in Myocardial Infarction (TIMI) criteria. Clinical evaluations were performed before and 24 hours, 7 to 10 days, and 1 to 3 months after treatment.

RESULTS

Nineteen consecutive patients were treated (mean age, 64.3 +/- 16.2 yr; 10 were men). Initial National Institutes of Health Stroke Scale scores ranged from 11 to 42. Time from onset to treatment ranged from 1 to 9 hours. Occlusion sites were in the following arteries: cervical internal carotid (n = 7), intracranial internal carotid (n = 1), middle cerebral (n = 9), and basilar (n = 2). Of the 19 patients, thrombolysis alone was used in 5 patients, angioplasty was performed in 11 patients, and snare maneuvers were used in 5 patients. Complete restoration of blood flow (modified TIMI Grade 4) was observed in 12 patients, near-complete restoration of flow (modified TIMI Grade 3) in 4 patients, minimal response (modified TIMI Grade 1) in 1 patient, and no response in 2 patients (modified TIMI Grade 0). Neurological improvement at 24 hours (decline of at least 4 points in National Institutes of Health Stroke Scale score) was observed in seven patients. Five other patients experienced further improvement in National Institutes of Health Stroke Scale score at 7 to 10 days. No vessel rupture, dissection, or symptomatic intracranial hemorrhages were observed. At the time of follow-up evaluation, 7 of 19 patients were functionally independent.

CONCLUSION

A high rate of recanalization and clinical improvement can be observed in patients with ischemic stroke using low-dose thrombolytic agents with adjunctive mechanical disruption of clot. Moreover, this strategy may reduce the risk of intracerebral hemorrhage observed with thrombolytics.

Neuroendovascular Rescue: Interventional Treatment of Acute Ischemic Stroke

Stroke continues to be a major health problem for our society. Despite the proven effectiveness of intravenous tissue plasminogen activator (t-PA) for the treatment of acute ischemic stroke, only a minority of patients qualify for this type of therapy. Furthermore, the existing literature has demonstrated that t-PA is not as effective in the treatment of occlusion of large cerebral arteries. The benefit-to-risk assessment of this subpopulation of stroke patients makes them the best candidates for neuroendovascular rescue. This term refers to the intra-arterial application of techniques designed to promote arterial recanalization, and includes intra-arterial thrombolysis and antithrombotic agents, direct mechanical disruption, angioplasty, stenting, embolectomy, and vasoactive pharmacologic intervention. The timing and choice of these procedures, as well as the care of the patient prior to, during, and after the intervention, requires a highly focused and expert approach.

Treatment of basilar artery embolism with a mechanical extraction device: necessity of flow reversal

BACKGROUND AND PURPOSE

The success of local fibrinolysis in vertebrobasilar thromboembolism depends on the volume and composition of the clot. Since thrombolysis can also be time consuming and cause bleeding, we investigated the feasibility of a mechanical clot retraction device based on a nitinol basket advanced through a microcatheter.

METHODS

Five patients with acute embolism of the basilar artery who presented with progressive stroke and impaired consciousness were included in a multicenter study (Neuronet Evaluation in Embolic Stroke Disease [NEED]). In 3 patients flow reversal was induced with the use of silicone balloons or coaxial catheters. Three patients required additional fibrinolysis.

RESULTS

The device failed to retrieve the clots in our first 2 patients with distal basilar artery embolism. After successful recanalization by local fibrinolysis, both patients survived, 1 disabled and 1 with little residual impairment. In the next 3 patients the anterograde flow in the basilar artery was reversed during the short retraction period by temporarily blocking the vertebral or subclavian arteries. Two of these patients were completely recanalized by solely mechanical means; the third patient needed additional fibrinolysis before also being recanalized. All 3 patients survived: 1 remained disabled, 1 had almost a full recovery, and 1 became asymptomatic the day after the procedure.

CONCLUSIONS

Mechanical thrombus extraction seems to be a feasible method for preventing infarction by rapid, complete, and safe recanalization of the basilar artery. We recommend the use of flow control to support retrieval of the thrombus (which the proximal flow would otherwise keep in place like a cork) and to protect the distal vessels from embolization by fragments.

Acute basilar artery occlusion treated with combined intravenous Abciximab and intra-arterial tissue plasminogen activator: report of 3 cases

BACKGROUND

Acute vertebrobasilar occlusion remains a disease with a high mortality even after treatment by local intra-arterial fibrinolysis. Adjunctive treatment with platelet glycoprotein IIb/IIIa receptor inhibitors such as abciximab may facilitate recanalization and improve the neurological outcome. Results after treatment of 3 patients by combined intravenous abciximab and local intra-arterial tissue plasminogen activator (tPA) are reported.

CASE DESCRIPTIONS

Treatment was performed within 6 hours of stroke onset. Angiography revealed embolic occlusion of the basilar artery in 2 patients and atherothrombotic occlusion at the vertebrobasilar junction in 1 patient. Therapy consisted of intravenous abciximab bolus administration (0.25 mg/kg) followed by 12-hour infusion therapy (0.125 microg/kg per minute) and local intra-arterial thrombolysis with tPA (10 mg/h). Heparin was only applied for catheter flushing (500 IU/h). The patient with the atherothrombotic occlusion was treated with additional percutaneous transluminal angioplasty and stenting. Complete recanalization of the basilar artery occurred in 2 patients, whose conditions improved clinically to functional independence. In the third patient only partial recanalization was seen, with only slight clinical improvement. This patient died of cardiac failure 2 months later. Besides a subtle subarachnoid hemorrhage (n=1), no intracranial or extracranial bleeding complication was observed.

CONCLUSIONS

The combination of glycoprotein IIb/IIIa receptor inhibitor with local intra-arterial tPA might be a promising therapy for patients with acute vertebrobasilar occlusion. Further studies are necessary to define the clinical benefit and the bleeding rate of this new pharmacological approach.