State-of-the-art reperfusion strategies for acute ischemic stroke

Caffeic acid alleviates cerebral ischemic injury in rats by resisting ferroptosis via Nrf2 signaling pathway

There are few effective and safe neuroprotective agents for the treatment of ischemic stroke currently. Caffeic acid is a phenolic acid that widely exists in a number of plant species. Previous studies show that caffeic acid ameliorates brain injury in rats after cerebral ischemia/reperfusion. In this study we explored the protective mechanisms of caffeic acid against oxidative stress and ferroptosis in permanent cerebral ischemia. Ischemia stroke was induced on rats by permanent middle cerebral artery occlusion (pMCAO). Caffeic acid (0.4, 2, 10 mg·kg-1·d-1, i.g.) was administered to the rats for 3 consecutive days before or after the surgery. We showed that either pre-pMCAO or post-pMCAO administration of caffeic acid (2 mg·kg-1·d-1) effectively reduced the infarct volume and improved neurological outcome. The therapeutic time window could last to 2 h after pMCAO. We found that caffeic acid administration significantly reduced oxidative damage as well as neuroinflammation, and enhanced antioxidant capacity in pMCAO rat brain. We further demonstrated that caffeic acid down-regulated TFR1 and ACSL4, and up-regulated glutathione production through Nrf2 signaling pathway to resist ferroptosis in pMCAO rat brain and in oxygen glucose deprivation/reoxygenation (OGD/R)-treated SK-N-SH cells in vitro. Application of ML385, an Nrf2 inhibitor, blocked the neuroprotective effects of caffeic acid in both in vivo and in vitro models, evidenced by excessive accumulation of iron ions and inactivation of the ferroptosis defense system. In conclusion, caffeic acid inhibits oxidative stress-mediated neuronal death in pMCAO rat brain by regulating ferroptosis via Nrf2 signaling pathway. Caffeic acid might serve as a potential treatment to relieve brain injury after cerebral ischemia. Caffeic acid significantly attenuated cerebral ischemic injury and resisted ferroptosis both in vivo and in vitro. The regulation of Nrf2 by caffeic acid initiated the transcription of downstream target genes, which were shown to be anti-inflammatory, antioxidative and antiferroptotic. The effects of caffeic acid on neuroinflammation and ferroptosis in cerebral ischemia were explored in a primary microglia-neuron coculture system. Caffeic acid played a role in reducing neuroinflammation and resisting ferroptosis through the Nrf2 signaling pathway, which further suggested that caffeic acid might be a potential therapeutic method for alleviating brain injury after cerebral ischemia.

Factors Affecting Pre-Hospital and In-Hospital Delays in Treatment of Ischemic Stroke; a Prospective Cohort Study

Introducion:

The outcomes of acute ischemic stroke (AIS) are highly affected by time-to-treatment. The present study aimed to determine the factors affecting in-hospital and pre-hospital delays in treatmentof AIS.

Methods:

This prospective study was carried out on 204 AIS patients referring to the stroke care unit in Zanjan (Iran) in 2019. The required data were collected by interviewing the patients and families and using patients’ records and observations.

Results:

The maximum delay was related to onset-to-arrival time (288.19 ± 339.02 minutes). The logistic regression analysis indicated a statistically significant decline in the treatment delay via consultation after the initiation of symptoms (p< 0.001), transferring the patient through emergency medical service to the hospital (p<0.001), and patients’ perception regarding AIS symptoms (P< 0.001).

Conclusion:

It is essential to inform people regarding AIS symptoms and referring to AIS treatment units to reduce the treatment time.

Emerging neuroprotective strategies for the treatment of ischemic stroke: An overview of clinical and preclinical studies

Stroke is the leading cause of disability and thesecond leading cause of death worldwide. With the global population aged 65 and over growing faster than all other age groups, the incidence of stroke is also increasing. In addition, there is a shift in the overall stroke burden towards younger age groups, particularly in low and middle-income countries. Stroke in most cases is caused due to an abrupt blockage of an artery (ischemic stroke), but in some instances stroke may be caused due to bleeding into brain tissue when a blood vessel ruptures (hemorrhagic stroke). Although treatment options for stroke are still limited, with the advancement in recanalization therapy using both pharmacological and mechanical thrombolysis some progress has been made in helping patients recover from ischemic stroke. However, there is still a substantial need for the development of therapeutic agents for neuroprotection in acute ischemic stroke to protect the brain from damage prior to and during recanalization, extend the therapeutic time window for intervention and further improve functional outcome. The current review has assessed the past challenges in developing neuroprotective strategies, evaluated the recent advances in clinical trials, discussed the recent initiative by the National Institute of Neurological Disorders and Stroke in USA for the search of novel neuroprotectants (Stroke Preclinical Assessment Network, SPAN) and identified emerging neuroprotectants being currently evaluated in preclinical studies. The underlying molecular mechanism of each of the neuroprotective strategies have also been summarized, which could assist in the development of future strategies for combinational therapy in stroke treatment.

Reperfusion therapy in acute ischemic stroke: dawn of a new era?

Following the success of recent endovascular trials, endovascular therapy has emerged as an exciting addition to the arsenal of clinical management of patients with acute ischemic stroke (AIS). In this paper, we present an extensive overview of intravenous and endovascular reperfusion strategies, recent advances in AIS neurointervention, limitations of various treatment paradigms, and provide insights on imaging-guided reperfusion therapies. A roadmap for imaging guided reperfusion treatment workflow in AIS is also proposed. Both systemic thrombolysis and endovascular treatment have been incorporated into the standard of care in stroke therapy. Further research on advanced imaging-based approaches to select appropriate patients, may widen the time-window for patient selection and would contribute immensely to early thrombolytic strategies, better recanalization rates, and improved clinical outcomes.

Role of Diffusion-weighted Imaging in Acute Stroke Management using Low-field Magnetic Resonance Imaging in Resource-limited Settings

A variety of imaging modalities exist for the diagnosis of stroke. Several studies have been carried out to ascertain their contribution to the management of acute stroke and to compare the benefits and limitations of each modality. Diffusion-weighted imaging (DWI) has been described as the optimal imaging technique for diagnosing acute ischemic stroke, yet limited evidence is available on the value of DWI in the management of ischemic stroke with low-field magnetic resonance (MR) systems. Although high-field MR imaging (MRI) is desirable for DWI, low-field scanners provide an acceptable clinical compromise which is of importance to developing countries posed with the challenge of limited availability of high-field units. The purpose of this paper was to systematically review the literature on the usefulness of DWI in acute stroke management with low-field MRI scanners and present the experience in Nigeria.

Predictors of prognosis and treatment outcome in central retinal artery occlusion: local intra-arterial fibrinolysis vs. conservative treatment

INTRODUCTION

The study analyses patients' risk factors to determine prognostic and predictive factors in patients with acute central retinal artery occlusion (CRAO) treated in the randomized European Assessment Group for Lysis in the Eye (EAGLE) Study with local intra-arterial fibrinolysis (LIF) or conservative standard treatment (CST). These data could improve patient selection for either method.

METHODS

Post hoc statistical analysis of effects of risk factors on overall best corrected visual acuity (BCVA [logarithm of the minimum angle of resolution (logMAR)]) at baseline and month 1 (prognostic effect) and on the difference between outcome of CST and LIF (predictive effect) was conducted.

RESULTS

Seventy two of 84 EAGLE datasets were included. Prognostic effect: Patients with coronary heart disease (CHD) presented worse BCVA at baseline (0.39 logMAR, p = 0.0097). Patients with time from occlusion to treatment <12 h showed a trend to better vision gain at month 1 (-0.23 logMAR, p = 0.086), similarly smoking (-0.24 logMAR, p = 0.077). Predictive effect: Age (<60 years favours LIF -0.54 logMAR; >70 years favours CST 0.28 logMAR; interaction p = 0.070) and CHD (favours CST 0.44 logMAR; interaction p = 0.073) might be predictors of therapeutic outcome. There were no strong effects in multivariate analysis.

CONCLUSION

CHD, time from occlusion to treatment and smoking influence BCVA at baseline and at month 1 (prognostic effect). Patients treated within 12 h are more likely to profit from treatment. In multivariate analysis, there is no clear trend to benefit from LIF even in patients with young age, no CHD and early treatment. Based on this preliminary report on a rather small sample size, we do not recommend LIF in CRAO patients.

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

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

Saving the ischemic penumbra: endovascular thrombolysis versus medical treatment

Endovascular thrombolysis may allow rapid arterial recanalization in patients with acute ischemic stroke. We present the first study to our knowledge comparing the ischemic penumbra saved with endovascular versus medical therapy. A retrospective review of 21 patients undergoing endovascular intervention for stroke from 2010 to 2011 was contrasted with 21 consecutive patients treated with antiplatelet agents alone. Immediate computed tomography perfusion (CTP) scan of the head and neck was obtained in all patients. Patients with lacunar and posterior circulation infarcts, and those who were medically unstable for MRI post-operatively were excluded. CTP and MRI underwent volumetric calculation. CTP penumbra was correlated with diffusion restriction volumes on MRI, and an assessment was made on the volume of ischemic burden saved with either endovascular treatment or antiplatelet agents. The median age was 70 years (interquartile range 62-80). Median National Institutes of Health Stroke Scale score was 18 and 14 in the control and endovascular groups, respectively. Intravenous tissue plasminogen activator was administered in 22 of 42 patients (52%). Median penumbra calculated was 32,808 mm(3) in the control group and 46,255 mm(3) in the endovascular group. Median penumbra spared was 9550 mm(3) (4980-18,811) in the control group versus 38,155 mm(3) in the endovascular group (p=0.0001). Endovascular thrombolysis may be more efficient than medical therapy alone in saving ischemic penumbra. Future advances in recanalization techniques will further improve the efficacy of endovascular therapy.

Extracranial carotid artery stenting followed by intracranial stent-based thrombectomy for acute tandem occlusive disease

OBJECTIVE

Acute tandem occlusions of the extracranial internal carotid artery (ICA) and a major intracranial artery respond poorly to intravenous tissue plasminogen activator (tPA) and present an endovascular challenge. We describe our experience with emergency stent-assisted ICA angioplasty and intracranial stent-based thrombectomy of tandem occlusions.

METHODS

Procedures were performed from March 2010 to December 2013. National Institutes of Health Stroke Score (NIHSS) and Alberta Stroke Program Early CT Score (ASPECTS), occlusion sites, collateral supply, procedural details, and outcomes were retrospectively reviewed with IRB waiver of informed consent.

RESULTS

24 patients, mean age 66 years, mean admission NIHSS 20.4, and mean ASPECTS 9 were included. Occlusion sites were proximal ICA-middle cerebral artery (MCA) trunk in 17 patients, proximal ICA-ICA terminus in six, and ICA-MCA-anterior cerebral artery in one. Stent-assisted cervical ICA recanalization was achieved in all patients, with unprotected pre-angioplasty in 24/24, unprotected stenting in 16/24 (67%), and protected stenting in 8/24 (33%), followed by stent-thrombectomy in 25 intracranial occlusions. There was complete recanalization/complete perfusion in 19/24 (79%), complete recanalization/partial perfusion in 3/24 (13%), and partial recanalization/partial perfusion in 2/24 (8%) with no procedural morbidity/mortality. Mean time to therapy was 3.8 h (range 2-5.5) and mean time to recanalization was 51 min (range 38-69). At 3-month follow-up, among 17/22 surviving patients (77%), 13/17 (76%) were modified Rankin Scale (mRS) 0-2 and 3/17 (18%) were mRS 3.

CONCLUSIONS

In acute tandem ICA-MCA/distal ICA occlusions, extracranial stenting followed by intracranial stent-based thrombectomy appears feasible, effective, and safe. Further evaluation of this treatment strategy is warranted.

Management of ischaemic stroke in the acute setting: review of the current status

Abstract

Acute ischaemic stroke can be treated by clot busting and clot removal. Thrombolysis using intravenous recombinant-tissue plasminogen activator (IV r-TPA) is the current gold standard for the treatment of acute ischaemic stroke (AIS). The main failure of this type of treatment is the short time interval from stroke onset within which it has to be used for any benefit. The evidence is that IV r-TPA has to be used within 4.5 hours.

Other modalities of treatment are not as effective and need more scrutiny and examination. The available modalities are intra-arterial thrombolysis and clot-retrieval devices. Not unexpectedly, recanalisation treatments have flourished at a rapid rate. Although vessel recanalisation is vital to increasing the possibility of significant tissue reperfusion, clinical trials need to emphasise functional outcomes rather than reperfusion/recanalisation rates to adequately assess success of these devices/techniques.

Our view is that until these treatments become proven in large-scale studies, a greater endeavour should be made in resource-limited settings to expand facilities to enable intravenous r-tPA treatment within the 4.5-hour period following onset of stroke. The resources required are small with the main costs being a CT scan of the brain and the cost of r-tPA. This can easily be done in any emergency facility in any part of the world. What is needed is public awareness, and campaigns of ‘stroke attack’ should be revisited, especially in the resource-limited context. This approach at present will halt to some extent the stroke pandemic that we are facing.

Use of heparin in neurointervention: a review of the literature

Background: The use of heparin is routine in endovascular procedures as a strategy in many centers that perform neurointerventional procedures to prevent occlusion of the catheters, but the use of this drug carries risks such as heparininduced thrombocytopenia.

Objective: The purpose of this paper is to present a review of the literature.

Material and methods: We conducted an extensive search and review of published papers about heparin and neurointerventional procedures.

Results: The evidence in the literature is weak in relation to the use of heparin and the reduction of embolic effects associated with their use in endovascular procedures.

Conclusion: The evidence on the use of heparin for the prevention of thromboembolic events in endovascular procedures are of low quality. There is insufficient evidence to conclude a potential benefit of heparin is useful in neurointerventional procedures. Prospective studies are needed to determine the effectiveness of heparin and avoid exposing patients to potential risks.

Cost-effectiveness of two endovascular treatment strategies vs intravenous thrombolysis

OBJECTIVE

To assess the cost-effectiveness of endovascular treatment against intravenous thrombolysis (IVT) when varying assumptions concerning its effectiveness.

METHODS

We developed a health economic model including a hypothetical population consisting of patients with ischemic stroke, admitted within 4.5 h from onset, without contraindications for IVT or intra-arterial treatment (IAT). A decision tree and life table were used to assess 6-month and lifetime costs (in Euros) and effects in quality-adjusted life years treatment with IVT alone, IAT alone, and IVT followed by IAT if the patient did not respond to treatment. Several analyses were performed to explore the impact of considerable uncertainty concerning the clinical effectiveness of endovascular treatment.

RESULTS

Probabilistic sensitivity analysis demonstrated a 54% probability of positive incremental lifetime effectiveness of IVT-IAT vs IVT alone. Sensitivity analyses showed significant variation in outcomes and cost-effectiveness of the included treatment strategies at different model assumptions.

CONCLUSIONS

Acceptable cost-effectiveness of IVT-IAT compared to IVT will only be possible if recanalization rates are sufficiently high (>50%), treatment costs of IVT-IAT do not increase, and complication rates remain similar to those reported in the few randomized studies published to date. Large randomized studies are needed to reduce the uncertainty concerning the effects of endovascular treatment.

Excellent rates of recanalization and good functional outcome after stent-based thrombectomy for acute middle cerebral artery occlusion. Is it time for a paradigm shift?

The natural history of untreated acute middle cerebral artery (MCA) occlusion is poor, with high rates of mortality (5-33%) and severe long-term disability (40-80% of survivors), despite therapy with intravenous tissue plasminogen activator. We analyzed outcomes in 31 consecutive patients with major ischemic stroke due to acute proximal MCA occlusion who were treated at the Hadassah-Hebrew University Medical Center from February 2010 to October 2012 by endovascular means, using the Solitaire stent (Covidien, Irvine, CA, USA) as a thrombectomy device. Patients had a mean age of 63.3±16.2 years (range, 26-92). The admission National Institutes of Health Stroke Scale score was 19.5±4.3 (median 20). Mean time from symptom onset to femoral artery puncture was 3.8±1.1 hours (median 4 hours). Mean time to recanalization was 46.9±11.1 minutes. Successful recanalization by means of stent-based thrombectomy alone was achieved in 90% of cases and reached 100% after combining definitive stent implantation in three patients. There was no arterial rupture or subarachnoid hemorrhage. Hemorrhagic transformation developed in seven patients (23%), but was symptomatic in only one. Post-procedure CT scan or MRI demonstrated >90% sparing of cortex at risk in all patients. Functional outcome at 90 day follow-up was modified Rankin Score 0-2 in 77% of all patients and 88% of patients younger than 80 years. Three patients (10%) died during hospitalization due to mesenteric event, sepsis, or pulmonary embolism. Our experience suggests that stent-based thrombectomy in selected patients for acute MCA occlusions is safe, very effective in terms of arterial recanalization, and associated with improved neurological outcome. If validated by other groups, endovascular treatment may be proposed as the therapy of choice for MCA occlusion.

Acute middle cerebral artery occlusion: reappraisal of the role of endovascular revascularization

Intravenous tissue plasminogen activator was the first successful stroke therapy in acute ischaemic stroke, after innumerable failed attempts at neuroprotection and neurorestoration. However, intravenous tissue type plasminogen activator has been shown to be effective in recanalizing middle cerebral artery occlusions in only about one-third of cases. The natural history of untreated acute middle cerebral artery occlusion is poor, leading to long-term disability in >70% and mortality in 20%. Recanalization alone is not the name of the game. Only timely, very rapid recanalization, achieved within minutes or at most a few hours after stroke has occurred, before irreversible brain damage develops, is effective. Is intravenous tissue type plasminogen activator the best available option we have for these patients? With recently introduced stent-based thrombectomy devices, neurointerventionalists have achieved complete recanalization rates of more than 90% in middle cerebral artery and 'T' occlusions, with a mean procedural recanalization time of less than one-hour and negligible complication rates. More than 80% of patients less than 80 years of age who were treated within eight-hours after stroke onset in our centre achieved a modified Rankin score of 0-2 at three-month follow-up. The site of arterial occlusion is a factor driving the choice between a standard intravenous tissue type plasminogen activator protocol and an alternative intervention such as intravenous and/or mechanical thrombolysis to achieve early recanalization. The role of intravenous tissue type plasminogen activator must be redefined in major occlusions, and the indications for endovascular therapy must also be reappraised.

Patient selection for intra-arterial cerebral revascularization in acute ischemic stroke

In acute ischemic stroke, rapid revascularization of the cerebral 'penumbra volume' is the key to better patient outcome. The largest and most proximal cerebral thrombotic artery occlusions can in most cases only be opened by intra-arterial intervention. The use of intra-arterial revascularization is rapidly expanding throughout Europe and North America, despite the risk for serious complications and the fact that the benefit of this treatment has not yet been proven in large, randomized clinical trials. Oslo University Hospital has performed approximately 60 intra-arterial procedures annually in acute ischemic stroke during the last few years. In this paper, we discuss important clinical and ethical aspects learned from our own experience. The future of intra-arterial cerebral revascularization will depend on an accurate preintervention patient selection.

Cellular replacement and regenerative medicine therapies in ischemic stroke

Worldwide, tissue engineering and cellular replacement therapies are at the forefront of the regenerative medicine agenda, and researchers are addressing key diseases, including diabetes, stroke and neurological disorders. It is becoming evident that neurological cell therapy is a necessarily complex endeavor. The brain as a cellular environment is complex, with diverse cell populations, including specialized neurons (e.g., dopaminergic, motor and glutamatergic neurons), each with specific functions. The population also contains glial cells (astrocytes and oligodendrocytes) that offer the supportive network for neuronal function. Neurological disorders have wide and varied pathologies; they can affect predominantly one cell type or a multitude of cell types, which is the case for ischemic stroke. Both neuronal and glial cells are affected by stroke and, depending on the region of the brain affected, different specialized cells are influenced. This review will address currently available therapies and focus on the application and potential of cell replacement, including stem cells and immortalized cell line-derived neurons as regenerative therapies for ischemic stroke, addressing current advances and challenges ahead.

Emergent stent-assisted angioplasty of extracranial internal carotid artery and intracranial stent-based thrombectomy in acute tandem occlusive disease: technical considerations

OBJECTIVE

Tandem occlusions of the internal carotid artery (ICA) and a major intracranial artery respond poorly to intravenous thrombolytic therapy, and are usually managed by endovascular means. This study describes experience with stent-assisted endovascular ICA revascularization and stent-based thrombectomy.

METHODS

In patients with tandem ICA-middle cerebral artery (MCA)/distal ICA occlusion, the carotid occlusion was recanalized by primary angioplasty and stent implantation, and the distal occlusion by stent-based thrombectomy. Two variant techniques are described.

RESULTS

Seven consecutive patients, mean age 64.1 years (range 49-75) and mean admission National Institutes of Health Stroke Scale score of 23, were included. Occlusion sites were tandem proximal ICA and MCA trunk (six patients) and tandem proximal left ICA and ICA terminus (one patient). Complete recanalization with complete perfusion (Thrombolysis in Myocardial Infarction [TIMI] 3, Thrombolysis in Cerebral Infarction [TICI] 3) was achieved in six patients and partial recanalization with partial perfusion (TIMI 2, TICI 2A) in one. Mean time to therapy was 4.9 h (range 3-6.5); mean time to recanalization was 55 min (range 38-65 min). CT performed 1 day after recanalization showed cortical sparing (>90% of the cortex at risk) in seven patients. Five patients (72%) presented with good clinical outcome (modified Rankin Scale (mRS) score 0-2) at 1 month; one patient (patient No 7) reached an mRS score of 3 and one patient died.

CONCLUSIONS

In selected cases of acute ICA occlusion and concomitant major vessel embolic stroke, angioplasty and stenting of the proximal occlusion and stent-based thrombectomy of the intracranial occlusion may be feasible, effective and safe, and provide early neurological improvement. Further experience and prospective studies are warranted.

Single-center experience on endovascular reconstruction of traumatic internal carotid artery dissections

BACKGROUND

Traumatic internal carotid artery dissection (CAD) has a potentially grave outcome. Anticoagulant therapy may be ineffective or contraindicated; surgery impractical. We present our experience with endovascular stenting in CAD patients.

METHODS

From 2004 to 2011, 23 patients with angiographically proven traumatic CAD underwent endovascular stent-assisted arterial reconstruction based on clinical and radiographic criteria: contraindication or failure of anticoagulation, evidence of impending ischemic stroke, or need for urgent intracranial revascularization. Dissections were graded based on degree of stenosis and extent of injury.

RESULTS

Seventeen patients (73.9%) presented with stroke or transient ischemic attack. Carotid revascularization was achieved with one (11 patients, 48%) or multiple stents (12 patients, 52%); distal protection was used rarely (three patients, 13%). No complications were directly attributed to stenting. Mean dissection-related stenosis improved from 72% ± 28.87% to 4% ± 8.29%. At a mean clinical follow-up of 28.7 months ± 31.9 months, 16 patients (69.6%) improved, six (26.1%) remained stable, and one (4.3%) had died secondary to multiple traumatic injuries. At long-term follow-up, no patient had a transient ischemic attack or stroke or presented evidence of de novo in-stent stenosis or stent thrombosis. There were no neurologic sequelae after partial or total discontinuation of antiplatelet therapy in seven patients undergoing trauma-related surgeries.

CONCLUSIONS

Selected cases of traumatic CAD can be safely managed by endovascular stent-assisted angioplasty. Procedural complications are infrequent; the need for postprocedure antiplatelet therapy is a concern. Early detection is essential to avoid stroke. Stenting restores the integrity of the vessel lumen immediately, efficiently prevents the occurrence or recurrence of ischemic events, and avoids the need of long-term anticoagulation.

The Usefulness of Compliant Balloon for Recanalization of Acute Ischemic Stroke

Objective

We report on our experience using a compliant balloon for treatment of thrombi resistant to simple mechanical thrombolysis.

Methods

We conducted a retrospective investigation of 46 consecutive acute ischemic stroke patients who were treated by intraarterial thrombolysis (IAT) between January 2008 and July 2010. We compared IAT results between the balloon group (BG) and the simple mechanical thrombolysis (with microcatheter and microguidewire) group (SG). The Thrombolysis in Myocardial Infarction (TIMI) grading system was used for grading of the degrees of vessel recanalization. In addition, a modified Thrombolysis in Cerebral Infarction (TICI) score was used for post-IAT TIMI grade 2 patients. Modified Rankin Scale scores were used at three months for assessment of clinical outcomes.

Results

Twenty of the 46 subjects were treated with a compliant balloon. The mean initial National Institutes of Health Stroke Scale score was 15.1 in the BG and 14 in the SG. The mean time from symptom onset to initiation of IAT was 225 minutes in the BG and 177 in the SG (p = 0.004). The overall rate of successful recanalization (TIMI grade 2 or 3) was 85% in the BG and 73% in the SG (p = 0.476). In the TIMI grade 2 group, modified TICI 2b was 90% in the BG and 16% in the SG (p = 0.001). Postprocedure intraparenchymal hemorrhage occurred in two subjects in the BG and 10 subjects in the SG (p = 0.029). No significant difference in clinical outcomes was observed between the BG and SG (p = 0.347).

Conclusions

The compliant balloon showed high potential for recanalization following acute ischemic stroke, especially when simple mechanical thrombolysis had failed.

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

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

Stent-based mechanical thrombectomy in acute basilar artery occlusion

Stent-based mechanical thrombectomy was recently proposed as an effective alternative to other mechanical techniques to achieve recanalization of large-vessel embolic occlusions in the anterior circulation. To our knowledge, there are no reports of the use of this technique in acute basilar artery occlusion (ABAO). We present a patient with complete endovascular recanalization of ABAO using a stent-based thrombectomy technique. Advantages and limitations of this technique in the management of ABAO are discussed. The stent-thrombectomy technique is promising, and will need further evaluation in posterior circulation stroke.

Historical perspective and future direction of thrombolysis research: the re-discovery of plasmin

Two issues have held the focus of thrombolysis research for over 50 years, namely, choosing between a plasminogen activator (PA) or plasmin as the best therapeutic agent and choosing between systemic or local administration. The original plasmin product of the 1950s was both ineffective and contaminated with PA, and catheter technology was not yet developed for routine clinical use. For decades, clinical practice has focused on PA and systemic administration, but today, PAs are often administered by catheter into thrombosed vessels, notably for peripheral arterial and graft occlusion and deep vein thrombosis, and increasingly for acute ischaemic stroke. Despite using catheter-delivered therapy, bleeding complications still occur, most severely expressed as symptomatic intracranial haemorrhage. New experimental data indicate that we should now reconsider plasmin as a viable, even preferable, thrombolytic agent. Plasmin requires catheter delivery to achieve thrombolysis, but this technical issue has been solved with modern technology and widespread presence of interventional suites. After local administration, plasmin will lyse thrombi; thereafter, any plasmin in the circulation will be rapidly neutralised. Pre-clinical studies confirm that plasmin has marked haemostatic safety advantage over t-PA. After more than 50 years, the field has come full circle, and plasmin as the thrombolytic agent and catheter use for local delivery of agent may represent a step forward in thrombolytic therapy.

Intervention in Stroke. The Future Ahead

The treatment for acute stroke is evolving and we present the initial results of 18 patients presenting to our institution over a period of eight months with acute stoke where CTA confirmed the presence of a thrombus. These patients were resistant to IV rtPA and underwent partial to complete clot retrieval with IA thrombolysis or in conjunction with mechanical thrombectomy. 13 of the 18 patients underwent mechanical thrombectomy and Solitaire AB device was used in 12 of these patients. Efficacy was assessed radiologically by post-treatment thrombolysis in myocardial infarction (TIMI) scores and clinically by a 30-day Modified Rankin Scale (MRS) score A TIMI score of 3 was achieved in 91% of patients undergoing mechanical thrombectomy with Solitaire AB device. 61% of our patient group had a discharge MRS of ≤ 2.