Angioplasty after intra-arterial thrombolysis for acute occlusion of intracranial arteries

Deep Learning-Based Automated Thrombolysis in Cerebral Infarction Scoring: A Timely Proof-of-Principle Study

Background and Purpose

Mechanical thrombectomy is an established procedure for treatment of acute ischemic stroke. Mechanical thrombectomy success is commonly assessed by the Thrombolysis in Cerebral Infarction (TICI) score, assigned by visual inspection of X-ray digital subtraction angiography data. However, expert-based TICI scoring is highly observer-dependent. This represents a major obstacle for mechanical thrombectomy outcome comparison in, for instance, multicentric clinical studies. Focusing on occlusions of the M1 segment of the middle cerebral artery, the present study aimed to develop a deep learning (DL) solution to automated and, therefore, objective TICI scoring, to evaluate the agreement of DL- and expert-based scoring, and to compare corresponding numbers to published scoring variability of clinical experts.

Methods

The study comprises 2 independent datasets. For DL system training and initial evaluation, an in-house dataset of 491 digital subtraction angiography series and modified TICI scores of 236 patients with M1 occlusions was collected. To test the model generalization capability, an independent external dataset with 95 digital subtraction angiography series was analyzed. Characteristics of the DL system were modeling TICI scoring as ordinal regression, explicit consideration of the temporal image information, integration of physiological knowledge, and modeling of inherent TICI scoring uncertainties.

Results

For the in-house dataset, the DL system yields Cohen’s kappa, overall accuracy, and specific agreement values of 0.61, 71%, and 63% to 84%, respectively, compared with the gold standard: the expert rating. Values slightly drop to 0.52/64%/43% to 87% when the model is, without changes, applied to the external dataset. After model updating, they increase to 0.65/74%/60% to 90%. Literature Cohen’s kappa values for expert-based TICI scoring agreement are in the order of 0.6.

Conclusions

The agreement of DL- and expert-based modified TICI scores in the range of published interobserver variability of clinical experts highlights the potential of the proposed DL solution to automated TICI scoring.

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.

Intra-arterial Thrombolysis in Second Trimester of Pregnancy. A Case Report

Here we present a successful intra-arterial thrombolysis performed in the second trimester of pregnancy (21 weeks). The intervention resulted in complete recanalization of the occluded right middle cerebral artery and favourable clinical and gestational outcome. Together with cases described in respective medical literature our report affirms that in pregnancy acute ischemic stroke could be treated effectively applying intra-arterial thrombolysis (using rt-PA). This therapy could provide opportunity to help in such desperate situations.

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.

Potential for the use of the Solitaire stent for recanalization of middle cerebral artery occlusion without a susceptibility vessel sign

BACKGROUND AND PURPOSE

Absence of the MCA susceptibility vessel sign (negative MCA susceptibility vessel sign) on gradient recalled-echo MR imaging in acute stroke is commonly associated with in situ stenosis and thrombotic occlusion. We evaluated the effectiveness and safety of the Solitaire stent as the first-line device for the recanalization of MCA occlusion with a negative MCA susceptibility vessel sign.

MATERIALS AND METHODS

Thirty-eight consecutive patients presenting with acute ischemic stroke due to MCA occlusion were treated by using the Solitaire AB stent alone or combined with thrombolytic drugs. Among these patients, 11 (7 men and 4 women; median age, 70 years; range, 49-89 years) who underwent multimodal stroke MR imaging before the endovascular procedure and had no MCA susceptibility vessel sign on the initial gradient recalled-echo MR imaging were included in this study. The primary end point was the recanalization of the occluded artery evaluated by the arterial occlusive lesion score. Clinical outcome was assessed at discharge and 90 days, as was the degree of residual MCA stenosis or reocclusion.

RESULTS

Successful recanalization (arterial occlusive lesion score ≥ II) without balloon angioplasty was obtained in 9 patients (81.8%). Six patients (54.5%) had an mRS score of ≤2 at 90 days. After a median of 147 days, no patient showed reocclusion on follow-up imaging. There were no symptomatic intracerebral hemorrhages.

CONCLUSIONS

The Solitaire stent is a feasible tool as the first-line device for multimodal endovascular recanalization therapy in acute ischemic stroke with a negative MCA susceptibility vessel sign. It has a good rate of successful and complete recanalization and is a fast yet safe procedure.

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.

Angioplasty in acute middle cerebral artery stroke due to atrial fibrillation selected by CT perfusion: a case report

We report the experience of a case of acute stroke in a patient affected by Rendu Osler syndrome and atrial fibrillation. The combination of dynamic computerized tomography perfusion scans and the use of a high-compliance balloon allowed increasing the treatment window for intra-arterial recanalization over 6 h after stroke onset in a patient with middle cerebral artery occlusion.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Intra-arterial therapy for acute ischemic stroke

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

Intra-arterial treatment methods in acute stroke therapy

Acute revascularization is associated with improved outcomes in ischemic stroke patients. It is unclear which method of intra-arterial intervention, if any, is ideal. Promising approaches in acute stroke treatment are likely a combination of intravenous and endovascular revascularization efforts, combining early treatment initiation with direct clot manipulation and/or PTA/stenting. In this review, we will discuss available thrombolytic therapies and endovascular recanalization techniques, beginning with chemical thrombolytic agents, followed by mechanical devices, and a review of ongoing trials. Further randomized studies comparing medical therapy, intravenous and endovascular treatments are essential, and their implementation will require the wide support and enthusiasm from the neurologic, neuroradiologic, and neurosurgical stroke communities.

Treatment of acute middle cerebral artery occlusion with a Solitaire AB stent: preliminary experience

We report our initial experience with a Solitaire AB neurovascular remodeling stent device in performing cerebral embolectomy in seven patients presenting to our institution with acute stroke who were resistant to iv thrombolytic drug treatment. The main inclusion criteria were: National Institutes of Health Stroke Scale (NIHSS) score ≥10; treatment performed within 8 h from the onset of symptoms and no large hypodensity on CT; and occlusion of a major cerebral artery on the CT angiogram. An admission and a post-interventional NIHSS score were calculated for all patients by two different neurologists. Efficacy was assessed radiologically by post-treatment thrombolysis in myocardial infarction (TIMI) scores and clinically by a 30-day Modified Rankin Scale (MRS) score. The mean duration of neurointerventional treatment was 84 min. All interventions were successful, with TIMI scores of 2 or 3 achieved in 100% of patients. There was one procedural complication in our series owing to a self-detached stent and one patient had a small asymptomatic basal ganglia haemorrhage. There was improvement of more than 4 points on the NIHSS score in 5 (72%) of the patients following treatment, of whom 4 (57%) had a 30-day MRS score of ≤2. The use of a Solitaire stent in acute stroke was safe, time-efficient and encouraging; however, a larger sample size will be required to further evaluate the use of this device, which could benefit a significant number of stroke patients.

MR imaging-based localized intra-arterial thrombolysis assisted by mechanical clot disruption for acute ischemic stroke due to middle cerebral artery occlusion

BACKGROUND AND PURPOSE

LIT-MCD is used in our institution for acute stroke due to MCA occlusion, with the goal of reducing symptomatic intracranial hemorrhage by maintaining recanalization of the occluded vessels. The purpose of the study was to investigate the safety and efficacy of LIT-MCD and to identify factors associated with a poor outcome in patients undergoing this procedure.

MATERIALS AND METHODS

LIT-MCD for MCA occlusion was performed in 90 of 1907 consecutive patients with acute stroke admitted to our institution. Radiographic data and clinical outcome were evaluated in the 90 patients, and factors predictive of a poor outcome (3-month mRS score, 3-6) were investigated by multivariate analysis.

RESULTS

Recanalization was achieved in 73 of the 90 patients (81%); symptomatic intracranial hemorrhage occurred in 7 (8%); procedure-related complications, in 9 (10%); and a favorable clinical outcome (3-month mRS score, 0-2), in 48 (53%). A high baseline NIHSS score (≥20), a low preprocedural ASPECTS on MR imaging (≤7), proximal M1 occlusion (in the horizontal segment of the MCA at or proximal to the lenticulostriate arteries), and no recanalization were significant predictors of a poor clinical outcome.

CONCLUSIONS

LIT-MCD is a safe and effective treatment for acute stroke due to MCA occlusion. However, further intervention is needed to improve the outcome of patients with proximal M1 occlusion.

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.

Percutaneous balloon angioplasty for acute occlusion of intracranial arteries

BACKGROUND

The benefits of intravenous thrombolysis for acute ischemic stroke are still limited.

OBJECTIVE

To evaluate the safety and efficacy of double-lumen balloon catheter-based reperfusion therapy with or without intra-arterial thrombolysis for acute occlusion of intracranial arteries.

METHODS

Fifty-nine patients with acute occlusion of intracranial arteries were enrolled. A Gateway balloon catheter was used to disrupt clots or dilate atheromatous plaques in every patient. The technical details, technique-related complications, recanalization rates, and clinical outcomes were analyzed.

RESULTS

The occlusion sites were internal carotid arteries in 17 patients, M1 segments in 32 patients, the M2 segment in 1 patient, a vertebral artery in 1 patient, and basilar arteries in 8 patients. Twenty-four patients (41%) were treated with thrombolysis first, and 20 patients (34%) were treated with percutaneous transluminal angioplasty (PTA) followed by thrombolysis. PTA alone was performed in 15 patients (25%). The mean dose of urokinase was 205 x 10 U. The extent of recanalization was complete (Thrombolysis in Myocardial Infarction [TIMI] score of 3) in 17 patients (29%), and partial (TIMI 1/2) in 28 patients (47%). Functional independence at discharge was preserved in 76%, 25%, and 7% of patients with TIMI 3, TIMI 1/2, and TIMI 0, respectively. A combination of PTA and thrombolysis resulted in a significantly higher recanalization rate than PTA only. Seven patients (12%) experienced hemorrhagic events after treatment. Severe parenchymal hemorrhage with neurologic deterioration was observed in 2 patients (4%), and vessel rupture was encountered in 1 atherosclerotic case.

CONCLUSIONS

Mechanical angioplasty using a Gateway catheter combined with a low-dose thrombolytic agent is a safe and effective treatment for acute intracranial embolic and atherosclerotic occlusion with a low risk of hemorrhagic complications.

Endovascular approaches to acute stroke, part 1: Drugs, devices, and data

Despite years of research and pioneering clinical work, stroke remains a massive public health concern. Since 1996, we have lived in the era of US Food and Drug Administration-approved intravenous (i.v.) recombinant tissue plasminogen activator (rtPA). This treatment, despite its promise, continues to exhibit its limitations. Endovascular therapy has several theoretic advantages over i.v. rtPA, including site specificity, longer treatment windows, and higher recanalization rates. In this article, we will review the various pharmacologic strategies for acute stroke treatment, providing both a historic context and the state of the art. The drugs will be classified on the basis of their theoretic rationale for therapy. Next, we will review the various devices and strategies for mechanical revascularization with an aim toward comprehensiveness. These range from wire disruption of thrombus to preclinical trials for novel mechanical solutions. This first installment of this 2-part series will end with an analysis of retrograde reperfusion techniques.

Neuroimaging of ischemic stroke with CT and MRI: advancing towards physiology-based diagnosis and therapy

Acute ischemic stroke is the third leading cause of death and the major cause of significant disability in adults in the USA and Europe. The number of patients who are actually treated for acute ischemic stroke is disappointingly low, despite availability of effective treatments. A major obstacle is the short window of time following stroke in which therapies are effective. Modern imaging is able to identify the ischemic penumbra, a key concept in stroke physiology. Evidence is accumulating that identification of a penumbra enhances patient management, resulting in significantly improved outcomes. Moreover, unexpectedly large proportions of patients have a substantial ischemic penumbra beyond the traditional time window and are suitable for therapy. The widespread availability of modern MRI and computed tomography systems presents new opportunities to use physiology to guide ischemic stroke therapy in individual patients. This article suggests an evidence-based alternative to contemporary acute ischemic stroke therapy.

Urgent Intracranial Angioplasty after Combined Systemic and Intra-Arterial Thrombolysis in Acute Stroke

We report a case of a 59-year-old man who presented with an acute stroke involving the territory of his left middle cerebral artery, and who was treated with combined systemic and intra-arterial thrombolysis. After these treatments, the segment remained stenotic. An urgent intracranial angioplasty was performed, resulting in satisfactory recanalization of the stenotic segment, and significant improvement of his National Institutes of Health Stroke Scale (NIHSS) from 14 to 5. This case report suggests an effective alternate protocol for treatment of acute stroke with arterial occlusion: immediate smaller dose of IV tissue plasminogen activator (tPA), followed by angiogram, intra-arterial thrombolysis, and angioplasty if indicated.

Mannitol enhances delivery of marrow stromal cells to the brain after experimental intracerebral hemorrhage

Previous studies show that intravascular injection of human bone marrow stromal cells (hBMSCs) significantly improves neurological functional recovery in a rat model of intracerebral hemorrhage (ICH). In the present study, we tested the hypothesis that mannitol improves the efficiency of intraarterial MSC delivery (i.e., fewer injected cells required for therapeutic efficacy) after ICH. There were four post-ICH groups (N=9): group 1, negative control with only intraarterial injection of 1 million human fibroblasts in phosphate-buffered saline (PBS); group 2, intravenous injection of mannitol alone in PBS (1.5 g/kg); group 3, intraarterial injection of 1 million hBMSCs alone in PBS; and group 4, intravenous injection of mannitol (1.5 g/kg) in PBS followed by intraarterial injection of 1 million hBMSCs in PBS. Group 4 exhibited significantly improved neurological functional outcome as assessed by neurological severity score (NSS) and corner test scores. Immunohistochemical staining of group 4 suggested increased synaptogenesis, proliferating immature neurons, and neuronal migration. The number of hBMSCs recruited to the injured region increased strikingly in group 4. Tissue loss was notably reduced in group 4. In summary, the beneficial effects of intraarterial infusion of MSCs are amplified with intravenous injection of mannitol. Preadministration of mannitol significantly increases the number of hBMSCs located in the ICH region, improves histochemical parameters of neural regeneration, and reduces the anatomical and pathological consequences of ICH.

Reperfusion Therapy for Acute Middle Cerebral Artery Trunk Occlusion. Direct Percutaneous Transluminal Angioplasty Versus Intra-arterial Thrombolysis

SUMMARY

The purpose of this study was to test the hypothesis that direct percutaneous transluminal angioplasty (PTA) might reduce the incidence of haemorrhagic complications and might improve recanalization rate and clinical outcome as compared with intra-arterial (IA) thrombolysis in patients with acute middle cerebral artery (MCA) trunk occlusion. A total of 70 patients with acute MCA trunk occlusion were treated with IA reperfusion therapy. Thirty-six patients were treated with IA thrombolysis alone. In the other 34 patients, direct PTA was selected as the first choice of the treatment and subsequent thrombolysis was added if necessary for distal embolization. The modified Rankin scale (mRS) was used to assess clinical outcome at 90 days. As compared with IA thrombolysis, direct PTA provided significant increase in the rates of partial or complete recanalization (63.9 vs 91.2%, p < 0.01) and decrease in the incidence of large parenchymal hematoma with neurological deterioration (19.4% vs 2.9%, p=0.03). Despite such favorable effects, direct PTA did not improve the rate of a favorable outcome (mRS score 0 or 1, 41.7% for the IA thrombolysis group vs 52.9% for the PTA group, p=0.48). However, outcome classified in terms of independence (mRS score </= 2) was significantly better in the PTA group (73.5%) than the IA thrombolysis group (50.0%, p=0.04). In patients with acute MCA trunk occlusion, as compared with IA thrombolysis, direct PTA improved recanalization rate and reduced serious haemorrhagic complications, resulting in a significant increase in independent patients.

Mechanical disruption of thrombus following intravenous tissue plasminogen activator for ischemic stroke

BACKGROUND AND PURPOSE

We prospectively evaluated the safety of aggressive mechanical disruption of thrombus following full-dose intravenous (IV) recombinant tissue plasminogen activator (rt-PA) to treat ischemic stroke in 24 patients with an initial National Institutes of Health stroke scale (NIHSS) score of >or=10.

METHODS

Clinical evaluations were performed at presentation and 24 hours, 7 to 10 days, and 1 to 3 months (using modified Rankin scale) after treatment. These end points were compared to matched historical controls treated with IV rt-PA alone.

RESULTS

Of the 24 patients, mechanical disruption was undertaken in 17 patients with persistent angiographic occlusion using microcatheter exploration (n= 3), angioplasty (n= 5), snare maneuvers (n= 7), and combination of both (n= 2). Partial or complete recanalization was observed in 10 of the 17 patients. Neurological improvement at 24 hours (>or=4 point reduction in NIHSS score) was observed in 11 of 17 patients. Comparisons with matched controls suggest potential equivalence for symptomatic ICH (0% vs 12%), asymptomatic ICH (18% vs 15%), and early neurological improvement (65% vs 53%).

CONCLUSION

The study shows that aggressive mechanical thrombus disruption in large artery occlusion in the setting of acute ischemic stroke is safe with acceptable rates of ICH and promotes angiographic recanalization.

Percutaneous Interventions in Patients with Acute Ischemic Stroke Related to Obstructive Atherosclerotic Disease or Dissection of the Extracranial Carotid Artery

PURPOSE

To determine the safety, feasibility, and efficacy of carotid artery stenting (CAS) in patients with acute stroke who underwent angioplasty of the extracranial internal carotid artery (ICA).

METHODS

Patients were eligible for CAS if they presented within 6 hours of symptom onset and had a National Institutes of Health Stroke Scale (NIHSS) score >4. The records of all 18 acute stroke patients (11 men; mean age 68.3+/-14.3 years) who underwent endovascular intervention in the stroke-related extracranial ICA between May 2003 and February 2006 were reviewed. Fourteen (77.8%) had atheromatous obstructions and 4 (22.2%) had dissection of the extracranial ICA. Major adverse cerebral and cardiac events (MACCEs) and neurological status, including NIHSS and the modified Rankin Scale (mRS) scores, were recorded for all patients.

RESULTS

Successful revascularization was achieved in 83.3% (15/18) of the patients. Cerebral protection devices were applied successfully in 13 (72.2%). At discharge, a neurological improvement (NIHSS reduction > or =4) was observed in 77.8% (14/18) of patients. The clinical success rate was 72.2% (13/18). The median NIHSS was 8.5 on admission versus 4.5 at discharge (p<0.01). The 30-day death and stroke rate was 11.1%. During the 14.6+/-9.3-month follow-up, the MACCE and the death/stroke rates were 33.3% and 27.8%, respectively. The median mRS scores at 30 days and at midterm follow-up were 1 and 2.5, respectively (p = NS).

CONCLUSION

Endovascular revascularization of the extracranial ICA in patients with acute ischemic stroke is associated with high procedural success rates and favorable midterm outcome.

Endovascular thrombolysis and stenting of a middle cerebral artery occlusion beyond 6 hours post-attack: special reference to the usefulness of diffusion-perfusion MRI

Intra-arterial thrombolysis and percutaneous angioplasty is feasible in patients with acute middle cerebral artery (MCA) occlusion limited to 6 hours post-ictus, but there are some limitations such as reocclusion or hemorrhagic complications. In this report, we describe a stent placement in the treatment of a refractory artherothrombotic MCA occlusion beyond 6 hours of symptom onset. A 57-year-old man presented with a progressive left-sided weakness and verbal disturbance resulting from an acute thrombotic occlusion of the right MCA superimposed on severe proximal atheromatous stenosis. Diffusion-perfusion magnetic resonance imaging (MRI) demonstrated the significant diffusion-perfusion mismatch. After chemical and mechanical thrombolysis of the clot, balloon angioplasty of the underlying MCA stenosis was performed 2 days post-attack, without significant angiographic improvement. Percutaneous endovascular deployment of a stent (Driver 2.5 x 12 mm, MTI, Irvine, CA) was subsequently performed, with excellent angiographic results. Follow-up diffusion-perfusion MRI showed improved perfusion in the hypoperfused area. The patient's National Institutes of Health Stroke Scale (NIHSS) score was increased from 12 to 3. Clot thrombolysis and subsequent stenting in patients with refractory proximal MCA occlusion is feasible and allows for a significant reduction in the amount of thrombolytic drug required. In selective patients with acute MCA occlusion, the therapeutic window for recanalization procedures can be safely and effectively extended beyond the 'traditional 6 hours'. Diffusion-perfusion MRI in acute MCA occlusion is important for indication of therapy.

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.

Safety and Efficacy of Thrombolytic Therapy in Postoperative Cerebral Infarctions

Acute ischemic stroke is a common and devastating complication of many surgical procedures. If diagnosed early, however, there are reasonably safe and effective treatment options. Although IV rtPA is the most well studied means of recanalization after ischemic stroke, it should be avoided within 14 days of a surgical procedure in favor of other locally directed techniques that carry a significantly lower risk of bleeding at the surgical site. Only in rare circumstances, when these newer modalities are not available and the surgery is minor, should IV rtPA be considered in postoperative patients. The treatment of choice for carefully selected patients with postoperative strokes is IAT with either rtPA or urokinase. IAT may be attempted up to 6 hours after an acute ischemic stroke and may be assisted by mechanical clot disruption/embolectomy in an attempt to improve recanalization rates. In patients who have had a recent craniotomy or any surgery where surgical site bleeding is expected to be massive or difficult to control or where small amounts of bleeding could be life threatening, IAT should be avoided. In these patients, and in patients who present greater than 6 hours but less than 8 hours after their stroke, mechanical thrombolysis/embolectomy may emerge as the only viable treatment option.

Successful Intra-Arterial Thrombolysis for Acute Ischemic Stroke in the Immediate Postpartum Period: Case Report

Stroke in pregnancy and the puerperium is a rare but potentially devastating event. We present the case of a previously healthy woman who underwent a cesarean delivery and experienced a middle cerebral artery thrombosis in the immediate postpartum period that was subsequently lysed with intra-arterial urokinase. The patient made a complete neurologic recovery. To the best of our knowledge, this is the first reported case of successful intra-arterial thrombolysis for ischemic stroke in the postpartum period.

Acute anterior circulation stroke: recanalization using clot angioplasty

BACKGROUND AND PURPOSE

Different strategies have been employed to recanalize acutely occluded middle cerebral and internal carotid arteries (ICA) in the setting of acute stroke including intravenous and intra-arterial tPA. However, pharmaceutical thrombolysis alone, may not be effective in patients with a large amount of clot volume (complete M1, terminal internal carotid artery). We report our initial experience with endovascular clot disruption using a soft silicone balloon in addition to intravenous or intra-arterial thrombolysis with tPA.

METHODS

This is a retrospective review of nine patients with symptoms of acute stroke from clot in the middle cerebral or internal carotid territories who were treated with intracranial balloon angioplasty. All patients presented with symptoms of acute anterior circulation stroke less than six hours from onset. Patients in whom computed tomography (CT) angiography confirmed the presence of large vessel clot (terminal ICA, M1 or proximal M2) were included in the study. A CT perfusion was performed providing maps of cerebral blood volume, flow and mean transit time. If the patient presented less than three hours from onset then intravenous tissue plasminogen activator (tPA) was also administered. Intra-arterial tPA was delivered into the clot. If the volume of clot was judged to be significant by the treating neurointerventionist, then a limited trial of tPA was administered intra-arterially followed by balloon angioplasty of persistant clot. The time from imaging to vessel recanalization was recorded. Clinical outcomes were assessed using the modified Rankin scale and Barthel Index.

RESULTS

Diagnostic CT perfusion studies were performed in 7 (78%), all of which showed a significant amount of salvageable tissue as judged by the treating neurointerventionist and neurologist. Recanalization (TIMI 2 or 3) was possible in 8 (89%). There were no cases of symptomatic intracranial hemorrhage and 2 (22%) asymptomatic hemorrhages. The average time from performance of the initial emergency CT to vessel recanalization was 2.1 hours with mean time from symptom onset to vessel recanalization of 4.1 hours. Five (56%) patients had good outcomes, 1 (11%) had mild and 3 (33%) had moderate to severe disability.

CONCLUSION

Clot angioplasty can potentially shorten recanalization times in well-selected patients and can be an effective complimentary procedure in patients with tPA resistant clot. Angioplasty can be performed with a very low complication rate using the technique described and may be associated with good outcomes.

Stroke: epidemiology, classification, risk factors, complications, diagnosis, prevention, and medical and dental management

Cerebrovascular accident, or stroke, refers to an acute onset of neurologic deficits lasting more than 24 hours or culminating in death caused by a sudden impairment of cerebral circulation. Stroke is the third leading cause of death and a major cause of long-term disability in the United States. This article provides the dental community with an up-to-date understanding of the epidemiology, classification, risk factors, complications, diagnosis, prevention, and medical and dental management issues pertaining to stroke.

Immediate catheter-directed reperfusion for acute stroke occurring during diagnostic cardiac catheterization

Acute stroke is a rare but the most dreaded complication of cardiac catheterization. We report a case about the management of an acute stroke that occurred during a diagnostic cardiac catheterization procedure. Immediate catheter-based intraarterial thrombolysis with adjunctive balloon angioplasty of the left middle cerebral artery was carried out. The patient recovered markedly within the first 2 hr and was discharged without neurological sequelae after 3 days. A clinical pathway for acute stroke management in the catheterization laboratory is discussed.

Revascularização clínica e intervencionista no acidente vascular cerebral isquêmico agudo: opinião nacional

Este artigo apresenta as conclusões sobre revascularização clínica e intervencionista no acidente vascular cerebral isquêmico agudo, um dos temas discutidos na reunião "Opinião Nacional sobre o Tratamento do AVC". Tratou-se de reunião promovida e coordenada pela Sociedade Brasileira de Doenças Cerebrovasculares, com neurologistas especializados em doenças cerebrovasculares, que analisaram e discutiram as evidências e experiências atuais sobre o uso de trombólise e técnicas intervencionistas em pacientes com acidente vascular cerebral isquêmico agudo.

[Interventional endovascular therapy (stenting) for residual stenosis after lysis of the basilar artery]

Despite the introduction of local thrombolytic therapy, there is still a very high mortality rate in basilar thrombosis. We report three cases of successful intra-arterial thrombolysis of acute basilar artery occlusion and consecutive interventional endovascular therapy. In all cases, the acute thrombosis of the basilar artery probably developed from preexisting atherosclerotic stenoses. The clinical outcomes were excellent. We discuss early consecutive stenting as a possible therapeutic option in cases of residual stenosis after successful intra-arterial lysis of basilar artery occlusion.

Catheter-based recanalization techniques for acute ischemic stroke

Recent advances in endovascular interventional therapies have revolutionized the management of acute ischemic stroke. For patients who present with occluded circle of Willis vessels, timely and successful arterial recanalization is the best predictor of clinical improvement. Diagnostic neuroimaging has advanced noninvasive tools--namely, transcranial Doppler, CT angiography, and MR angiography--to screen individuals with acute neurologic syndromes rapidly for arterial occlusion, and hence to exclude from treatment those who are unlikely to benefit from or could be harmed by arterial recanalization strategies. Intra-arterial thrombolysis has been proven to be of benefit in large clinical trials. Moreover, the US Food and Drug Administration has recently approved the use of a mechanical clot retrieval device for acute embolic stroke, and a number of other similar strategies are under various stages of investigation. This article reviews the diagnostic and interventional approach to the management of large vessel embolic stroke.

Antiplatelet Therapy in Neuroendovascular Therapeutics

Our understanding of the pharmacology of antiplatelet therapy continues to evolve rapidly. Although the existing data are primarily generated in the setting of interventional and preventative cardiology studies, these data may be extrapolated to guide the rational application of these agents in neuroendovascular procedures. Platelet function testing represents an increasingly available and practical method by which to verify the adequacy of therapy and guide clinical decision making. The optimal application of these agents will undoubtedly improve the risk profile of neuroendovascular procedures, increase the success rate of acute stroke intervention, and facilitate more effective secondary stroke prevention.

[Mechanical recanalization in acute stroke treatment]

The development of endovascular techniques for the treatment of acute stroke began with the introduction of local intra-arterial fibrinolysis. In parallel to designing new systemic therapy approaches, catheter systems for loosening, disintegrating, or removing cerebral thrombi have undergone assessment in recent years to serve as alternatives or supplements to fibrinolytic treatment. Mechanical alteration of intracranial thrombi with balloon catheters, manipulations with the guide wire, or ultrasound waves transmitted into the vascular system as well as techniques for thrombus aspiration, snare extraction, or more complex hydrodynamic or laser-guided thrombectomy systems have been tested in feasibility studies, which evidenced basic functionality and relative safety. Broad clinical applications outside of the clinical trial setting cannot yet be recommended since the new catheter systems are still in early phase clinical testing.

Acute Subdural Hematoma After Intro-arterial Thrombolysis for Acute Ischemic Stroke-Case Report-

A 79-year-old man with a cardiac pacemaker for bradycardia fell down and presented with sudden onset of right hemiplegia and aphasia. Initial computed tomography (CT) showed no cerebral infarction but angiography revealed occlusion of the left middle cerebral artery (MCA). Local intra-arterial thrombolysis with tissue plasminogen activator (tPA; tisokinase, 1,600,000 units) was performed 3 hours after the onset, and the MCA was partially recanalized. Further administration of tPA was suspended because of nosebleed. However, the patient's neurological findings did not improve. His consciousness gradually deteriorated to coma and quadriplegia with dilation of the left pupil 2.5 hours after thrombolysis. CT disclosed marked mass effect with a left acute subdural hematoma and a small intracerebral hematoma in the left frontal lobe. He underwent urgent craniotomy and removal of the subdural hematoma. The subdural hematoma originated in a frontal cerebral contusion. He died of severe brain edema 2 days after surgery. Acute subdural hematoma is a very rare complication of intra-arterial thrombolysis. Presumably he had suffered head trauma at the first onset. Evidence of head trauma should be considered a contraindication for the use of thrombolytic agents in a patient with acute stroke.

Intra-arterial Thrombolysis for Acute Ischemic Stroke: Preliminary Experience with Platelet Glycoprotein IIb/IIIa Inhibitors as Adjunctive Therapy

OBJECTIVE:

To evaluate the safety profile of platelet glycoprotein IIb/IIIa inhibitors administered as adjunctive therapy to patients with large-vessel occlusion and acute ischemic stroke refractory to pharmacological thrombolysis with recombinant tissue plasminogen activator (rtPA) and mechanical disruption, balloon angioplasty, or both.

METHODS:

Twenty-one patients (mean age, 62 yr; range, 29–88 yr) met the following criteria: 1) large-vessel occlusion and acute ischemic stroke syndrome at presentation, 2) failure to recanalize after administration of rtPA (intra-arterial and/or intravenous) with or without mechanical thrombolysis, and 3) subsequent treatment with IIb/IIIa inhibitors (intra-arterial or intravenous).

RESULTS:

Eleven patients had ischemia in the dominant hemisphere, 8 in the vertebrobasilar system, and 2 in the nondominant hemisphere. Twelve patients received intravenous rtPA without significant improvement; 9 patients were not candidates for intravenous rtPA. All patients received intra-arterial rtPA. The IIb/IIIa inhibitors were administered intravenously in 3 patients, intra-arterially in 16, and both intravenously and intra-arterially in 2. Balloon angioplasty was performed in 18 patients. Complete or partial recanalization was achieved in 17 of the 21 patients. After thrombolysis, 15 improved clinically. Three patients (14%) sustained an asymptomatic intracerebral hemorrhage after thrombolytic therapy. No patient was clinically worse after intervention. At last follow-up (mean, 8.5 mo), 13 patients were functionally independent (modified Rankin score, 0–3) and 8 were disabled or dead.

CONCLUSION:

IIb/IIIa inhibitors are an alternative for achieving recanalization. The risk of hemorrhage may be low. As part of an escalating protocol that includes pharmacological and mechanical thrombolysis, IIb/IIIa inhibitors may improve clinical outcomes.

Management of acute ischemic stroke

The treatment of acute ischemic stroke has evolved from observation and the passage of time dictating outcome to an approach that emphasizes time from ictus, rapid response, and a dedicated treatment team. We review the treatment of acute ischemic stroke from the prehospital setting, to the emergency department, to the inpatient hospital setting. We discuss the importance of prehospital assessment and treatment, including the use of elements of the neurologic examination, recognition of symptoms that can mimic those of acute ischemic stroke, and rapid transport of patients who are potential candidates for thrombolytic therapy to hospitals with that capability. Coordinated management of acute ischemic stroke in the emergency department is critical as well, beginning with non-contrast-enhanced computed tomography of the brain. The advantages of a multidisciplinary dedicated stroke team are discussed, as are thrombolytic therapy and other inpatient treatment options. Finally, we cover evolving management strategies, treatments, and tools that could improve patient outcomes.

Local saline infusion into ischemic territory induces regional brain cooling and neuroprotection in rats with transient middle cerebral artery occlusion

OBJECTIVE

The neuroprotective effect of hypothermia has long been recognized. Use of hypothermia for stroke therapy, which is currently being induced by whole-body surface cooling, has been limited primarily because of management problems and severe side effects (e.g., pneumonia). The goal of this study was to determine whether local infusion of saline into ischemic territory could induce regional brain cooling and neuroprotection.

METHODS

A novel procedure was used to block the middle cerebral artery of rats for 3 hours with a hollow filament and locally infuse the middle cerebral artery-supplied territory with 6 ml cold saline (20 degrees C) for 10 minutes before reperfusion.

RESULTS

The cold saline infusion rapidly and significantly reduced temperature in cerebral cortex from 37.2 +/- 0.1 to 33.4 +/- 0.4 degrees C and in striatum from 37.5 +/- 0.2 to 33.9 +/- 0.4 degrees C. The significant hypothermia remained for up to 60 minutes after reperfusion. Significant (P < 0.01) reductions in infarct volume (approximately 90%) were evident after 48 hours of reperfusion. In ischemic rats that received the same amount of cold saline systemically through a femoral artery, a mild hypothermia was induced only in the cerebral cortex (35.3 +/- 0.2 degrees C) and returned to normal within 5 minutes. No significant reductions in infarct volume were observed in this group or in the ischemic group with local warm saline infusion or without infusion. Furthermore, brain-cooling infusion significantly (P < 0.01) improved motor behavior in ischemic rats after 14 days of reperfusion. This improvement continued for up to 28 days after reperfusion.

CONCLUSION

Local prereperfusion infusion effectively induced hypothermia and ameliorated brain injury from stroke. Clinically, this procedure could be used in acute stroke treatment, possibly in combination with intra-arterial thrombolysis or mechanical disruption of clot by means of a microcatheter.

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.

Rescue angioplasty after failed intra-arterial thrombolysis in acute middle cerebral artery stroke: A case report

Intra-arterial thrombolysis is increasingly being used in the treatment of acute ischemic stroke with a failure rate of recanalization as high as 66%. We describe a case of acute ischemic stroke secondary to occlusion of the middle cerebral artery that failed intra-arterial thrombolytic therapy but responded to rescue balloon angioplasty.

Clinical potential of intra-arterial thrombolytic therapy in patients with acute ischaemic stroke

Acute ischaemic stroke is a leading cause of mortality and morbidity around the world. An arterial occlusive lesion is found in the majority of patients with acute ischaemic stroke, and recanalisation has been shown to result in a better clinical outcome. The only widely approved recanalisation strategy is the use of intravenous alteplase (recombinant tissue-type plasminogen activator; tPA) within 3 hours of stroke onset. However, this therapy has limitations, and alternative or supplemental recanalisation strategies need to be considered in a large number of patients with acute ischaemic stroke. One such promising strategy is intra-arterial thrombolysis. This article reviews the pharmacology of the various drugs used for intra-arterial thrombolysis in the setting of acute ischaemic stroke and the results of the clinical trials that have studied their benefit. Three generations of thrombolytic agents have been available for clinical use so far. The first-generation agents such as streptokinase and urokinase were the first to be studied in acute stroke, and a number of positive case reports and series of their intra-arterial use have been reported from around the world. Second-generation products include alteplase and pro-urokinase. The clinical benefits of intra-arterial pro-urokinase were recently proven in a randomised, placebo-controlled study. Third-generation agents, such as reteplase, lanoteplase and tenecteplase, offer superior recanalisation rates with limited systemic adverse effects and might prove to be the agents of choice for intra-arterial acute stroke thrombolysis in the future. The exact administration regimens as well as the identification of patient sub-populations most likely to benefit from intra-arterial thrombolysis are subjects of current investigations, and hopefully firmer guidelines will be established in the next few years, once the results of the clinical trials are available.

The 5 Ps of acute ischemic stroke treatment: parenchyma, pipes, perfusion, penumbra, and prevention of complications

Stroke is a treatable disease. Despite the therapeutic nihilism of the past, the advent of thrombolysis has changed the way stroke is approached. Acute ischemic stroke is a challenging and heterogeneous disease. Treatment needs to be based on an understanding of the underlying pathophysiology of ischemia. Interventions are designed to improve neuronal salvage and outcome. The underlying tenets of stroke therapy focus on the brain parenchyma, arterial flow (pipes), perfusion, the ischemic milieu or penumbra, and prevention of complications. This article focuses on the practical issues of ischemic stroke care, with a brief review of supporting literature.