Factors predicting hemorrhagic complications after multimodal reperfusion therapy for acute ischemic stroke

Cerebral Ischemic Reperfusion Injury: Preventative and Therapeutic Strategies

Acute ischemic stroke is a leading cause of morbidity and mortality in the United States. Treatment goals remain focused on restoring blood flow to compromised areas. However, a major concern arises after reperfusion occurs. Cerebral ischemic reperfusion injury is defined as damage to otherwise salvageable brain tissue occurring with the reestablishment of the vascular supply to that region. The pool of eligible patients for revascularization continues to grow, especially with the recently expanded endovascular therapeutic window. Neurointensivists should understand and manage complications of successful recanalization. In this review, we examine the pathophysiology, diagnosis, and potential management strategies in cerebral ischemic reperfusion injury.

Types of intraparenchymal hematoma as a predictor after revascularization in patients with anterior circulation acute ischemic stroke

Background:

Intracranial hemorrhage after revascularization for acute ischemic stroke is associated with poor outcomes. Few reports have examined the relationship between parenchymal hematoma after revascularization and clinical outcomes. This retrospective study aimed to investigate the risk factors and clinical outcomes of parenchymal hematoma after revascularization for acute ischemic stroke.

Methods:

Ninety-three patients underwent revascularization for anterior circulation acute ischemic stroke. Patient characteristics and clinical outcomes were compared between patients with and without post procedural parenchymal hematoma using the following parameters: age, sex, occlusion location, presence of atrial fibrillation, diffusion-weighted imaging-Alberta stroke program early computed tomography score (DWI-ASPECTS), National Institute of Health Stroke Scale (NIHSS) score, recombinant tissue plasminogen activator, thrombolysis in cerebral infarction > 2b, door-to-puncture time, onset-to-recanalization time, number of passes, and modified Rankin Scale scores.

Results:

Parenchymal hematomas were not significantly correlated with age, sex, occlusion location, atrial fibrillation, DWI-ASPECTS, NIHSS score, recombinant tissue plasminogen activator, thrombolysis in cerebral infarction > 2b, door-to-puncture time, onset-to-recanalization time, and number of passes, but were significantly correlated with poor clinical outcomes (P = 0.001) and absence of the anterior communicating artery evaluated using pre procedural time-of-flight magnetic resonance angiography (P = 0.03).

Conclusion:

Parenchymal hematoma was a predictor of poor outcomes. In particular, the absence of the anterior communicating artery on pre procedural time-of-flight magnetic resonance angiography is a potential risk factor for parenchymal hematoma after revascularization for anterior circulation acute ischemic stroke.

Effect of Conscious Sedation vs. General Anesthesia on Outcomes in Patients Undergoing Mechanical Thrombectomy for Acute Ischemic Stroke: A Prospective Randomized Clinical Trial

Background: Although several studies have compared conscious sedation (CS) with general anesthesia (GA) in patients undergoing mechanical thrombectomy (MT), there has been no affirmative conclusion. We conducted this trial to assess whether CS is superior to GA for patients undergoing MT for acute ischemic stroke (AIS).

Methods: Acute ischemic stroke patients with anterior circulation large vascular occlusion were randomized into two groups. The primary outcome was modified Rankin scale score (0–2) at 90 days after stroke. Secondary outcomes included intraprocedural hemodynamics, time metrics, successful recanalization, neurointerventionalist satisfaction score, National Institutes of Health Stroke Scale (NIHSS) score, and Alberta Stroke Program Early CT Score (ASPECTS) at 48 h post-intervention, mortality at discharge and 3 months after stroke, and complications.

Results: Compared with the CS group, heart rate was significantly lower at T1–T8 in the GA group except at T4 (P < 0.05). Mean arterial pressure (MAP) and systolic blood pressure were significantly lower in the GA group at T4–T6 and T9 (P < 0.05). Pulse oxygen saturation was significantly higher at T2–T9 in the GA group (P < 0.05). There were no significant differences in time metrics, vasoactive drug use, occurrence of >20% fall in MAP, pre-recanalization time spent with >20% fall in MAP, neurointerventionalist satisfaction, successful recanalization rate, NIHSS, and ASPECTS scores at 48 h post-intervention, and mortality rate at discharge and 3 months after stroke (P > 0.05). The cerebral infarction rate at 30 days was greater in the CS group, but not significantly (P > 0.05). There were no differences in complication rates except for pneumonia (P > 0.05). Conversion rate from CS to GA was 9.52%.

Conclusion: Anesthetic management with GA or CS during MT had no differential impact on the functional outcomes and mortality at discharge or 3 months after stroke in AIS patients, but CS led to more stable hemodynamics and lower incidence of pneumonia.

Neuroimaging of Acute Stroke

Acute stroke is the clinical manifestation of disrupted blood flow or bleeding in the central nervous system. Imaging supports the clinical diagnosis and can aide in acute treatment decision making and guide information on prognosis. Features that are delineated include the parenchyma and the blood vessels. Parenchymal characteristics include early ischemic changes, established infarct and tissue at risk (penumbra), and hemorrhage. Vessel pathology includes arterial and venous steno-occlusive disease and vascular malformations. In the presence of a vessel occlusion, vessel imaging can assess collateral flow. This article outlines the role of neuroimaging as applied to patients presenting with acute stroke.

Endovascular Stroke Therapy with a Novel 6-French Aspiration Catheter

BACKGROUND AND PURPOSE

Direct thrombus aspiration is increasingly used as a first-line therapy in acute ischemic stroke with large vessel occlusion. We assessed the performance and safety of a novel aspiration catheter available: the 6-French AXS Catalyst catheter.

MATERIALS AND METHODS

We conducted a cohort study from a prospective clinical registry of consecutive stroke patients treated by mechanical thrombectomy between March 2016 and July 2016. Baseline clinical and imaging characteristics, recanalization rates, complications, and clinical outcomes were analyzed.

RESULTS

Among the 60 patients included, 30 were treated using aspiration alone, 14 were treated using aspiration and then stent retriever as a rescue therapy, and 16 were treated using aspiration combined with a stent retriever straightaway. Successful recanalization (mTICI2b/3) was achieved in 85% patients and functional independence in 48.3%. We observed one intracranial perforation and one vertebral artery dissection. Symptomatic intracranial hemorrhage occurred in 5% and mortality in 21.7%.

CONCLUSION

Endovascular stroke therapy using the AXS Catalyst catheter seems safe and effective, with similar performance than other reperfusion catheters.

ACR Appropriateness Criteria® Cerebrovascular Disease

Diseases of the cerebral vasculature represent a heterogeneous group of ischemic and hemorrhagic etiologies, which often manifest clinically as an acute neurologic deficit also known as stroke or less commonly with symptoms such as headache or seizures. Stroke is the fourth leading cause of death and is a leading cause of serious long-term disability in the United States. Eighty-seven percent of strokes are ischemic, 10% are due to intracerebral hemorrhage, and 3% are secondary to subarachnoid hemorrhage. The past two decades have seen significant developments in the screening, diagnosis, and treatment of ischemic and hemorrhagic causes of stroke with advancements in CT and MRI technology and novel treatment devices and techniques. Multiple different imaging modalities can be used in the evaluation of cerebrovascular disease. The different imaging modalities all have their own niches and their own advantages and disadvantages in the evaluation of cerebrovascular disease. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Cerebral Ischemic Reperfusion Injury Following Recanalization of Large Vessel Occlusions

Although stroke has recently dropped to become the nation's fifth leading cause of mortality, it remains the top leading cause of morbidity and disability in the US. Recent advances in stroke treatment, including intravenous fibrinolysis and mechanical thromboembolectomy, allow treatment of a greater proportion of stroke patients than ever before. While intra-arterial fibrinolysis with recombinant tissue plasminogen is an effective for treatment of a broad range of acute ischemic strokes, endovascular mechanical thromboembolectomy procedures treat severe strokes due to large artery occlusions, often resistant to intravenous drug. Together, these procedures result in a greater proportion of revascularized stroke patients than ever before, up to 88% in 1 recent trial (EXTEND-IA). Subsequently, there is a growing need for neurointensivists to develop more effective strategies to manage stroke patients following successful reperfusion. Cerebral ischemic reperfusion injury (CIRI) is defined as deterioration of brain tissue suffered from ischemia that concomitantly reverses the benefits of re-establishing cerebral blood flow following mechanical or chemical therapies for acute ischemic stroke. Herein, we examine the pathophysiology of CIRI, imaging modalities, and potential neuroprotective strategies. Additionally, we sought to lay down a potential treatment approach for patients with CIRI following emergent endovascular recanalization for acute ischemic stroke.

Neurocritical Care of Emergent Large-Vessel Occlusion: The Era of a New Standard of Care

Acute ischemic stroke continues to be one of the leading causes of morbidity and mortality worldwide. Recent advances in mechanical thrombectomy techniques combined with prereperfusion computed tomographic angiography for patient selection have revolutionized stroke care in the past year. Peri- and postinterventional neurocritical care of the patient who has had an emergent large-vessel occlusion is likely an equally important contributor to the outcome but has been relatively neglected. Critical periprocedural management issues include streamlining care to speed intervention, blood pressure optimization, reversal of anticoagulation, management of agitation, and selection of anesthetic technique (ie, general vs monitored anesthesia care). Postprocedural critical care issues that might modulate neurological outcome include blood pressure and glucose optimization, avoidance of fever or hyperoxia, fluid and nutritional management, and early integration of rehabilitation into the intensive care unit setting. In this review, we sought to lay down an evidence-based strategy for patients with acute ischemic stroke undergoing emergent endovascular reperfusion.

Intravenous tissue plasminogen activator before endovascular treatment increases symptomatic intracranial hemorrhage in patients with occlusion of the middle cerebral artery second division: subanalysis of the RESCUE-Japan Registry

INTRODUCTION

No previous study has investigated the relationship between intravenous tissue plasminogen activator (IV t-PA) and intracranial hemorrhage (ICH) according to the location of vessel occlusion. The aim of the present study was to investigate the relationship between preprocedural IV t-PA and endovascular treatment (EVT) and ICH according to the location of occlusion using data from the nationwide prospective registry of acute cerebral large vessel occlusion (LVO), the RESCUE-Japan Registry.

METHODS

Among 1442 patients with acute LVO enrolled in the registry, we examined 410 patients who received EVT. Patients were divided into the following four groups according to the location of occlusion: the internal carotid artery (ICA), middle cerebral artery first division (M1), middle cerebral artery second division (M2), and vertebral artery (VA)/basilar artery (BA) groups.

RESULTS

A total of 399 patients in whom the occlusion was located in these vessels were finally included. Any ICH (aICH) was identified in 127 (30.9%) patients, and symptomatic ICH (sICH) was identified in 20 (4.9%). Preprocedural IV t-PA did not increase the incidence of aICH in any group and tended to increase the incidence of sICH in only the M2 group. In multivariate analysis of the M2 group, IV t-PA was an independent risk factor for sICH.

CONCLUSION

Preprocedural IV t-PA did not increase the incidence of ICH in total, but could increase the incidence of sICH in those with M2 occlusion. IV t-PA before EVT may be an independent risk factor for sICH in patients with M2 occlusion.

Impact of General Anesthesia on Safety and Outcomes in the Endovascular Arm of Interventional Management of Stroke (IMS) III Trial

BACKGROUND AND PURPOSE

General anesthesia (GA) for endovascular therapy (EVT) of acute ischemic stroke may be associated with worse outcomes.

METHODS

The Interventional Management of Stroke III trial randomized patients within 3 hours of acute ischemic stroke onset to intravenous tissue-type plasminogen activator±EVT. GA use within 7 hours of stroke onset was recorded per protocol. Good outcome was defined as 90-day modified Rankin Scale ≤2. A multivariable analysis adjusting for dichotomized National Institutes of Health Stroke Scale (NIHSS; 8-19 versus ≥20), age, and time from onset to groin puncture was performed.

RESULTS

Four hundred thirty-four patients were randomized to EVT, 269 (62%) were treated under local anesthesia and 147 (33.9%) under GA; 18 (4%) were undetermined. The 2 groups were comparable except for median baseline NIHSS (16 local anesthesia versus 18 GA; P<0.0001). The GA group was less likely to achieve a good outcome (adjusted relative risk, 0.68; confidence interval, 0.52-0.90; P=0.0056) and had increased in-hospital mortality (adjusted relative risk, 2.84; confidence interval, 1.65-4.91; P=0.0002). Those with medically indicated GA had worse outcomes (adjusted relative risk, 0.49; confidence interval, 0.30-0.81; P=0.005) and increased mortality (relative risk, 3.93; confidence interval, 2.18-7.10; P<0.0001) with a trend for higher mortality with routine GA. There was no significant difference in the adjusted risks of subarachnoid hemorrhage (P=0.32) or symptomatic intracerebral hemorrhage (P=0.37).

CONCLUSIONS

GA was associated with worse neurological outcomes and increased mortality in the EVT arm; this was primarily true among patients with medical indications for GA. Relative risk estimates, though not statistically significant, suggest reduced risk for subarachnoid hemorrhage and symptomatic intracerebral hemorrhage under local anesthesia. Although the reasons for these associations are not clear, these data support the use of local anesthesia when possible during EVT.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00359424.

[Angiographically documented hemorrhagic transformation of embolic stroke: A case report]

A 81-year-old man with rheumatoid vasculitis presented with total aphasia followed by right hemiplegia. The NIHSS score was 24. Diffusion weighted magnetic resonance imaging (DWI) demonstrated an acute infarct in the left middle cerebral artery (MCA) territory, and magnetic resonance angiogram (MRA) revealed left MCA M1 occlusion. We administrated recombinant tissue plasminogen activator (rt-PA) at 132 min after symptom onset, but symptom was not improved. Emergency neuroendovascular recanalization was conducted with Penumbra(®) system. After MCA was recanalized partially, extravasations appeared on left lenticulostriate arteries territory at 376 min from symptom onset. Multiple extravasations spread over perforating branches, and ventricular rupture recognized angiographically. After the procedure, head CT demonstrated hematoma on left basal ganglia territory with intraventricular bleeding. Rheumatoid vasculitis might affect hemorrhagic infarction in emergency neuroendovascular recanalization procedure, and careful choice of treatment would be required.

Predictors and clinical relevance of hemorrhagic transformation after endovascular therapy for anterior circulation large vessel occlusion strokes: a multicenter retrospective analysis of 1122 patients

BACKGROUND AND PURPOSE

Endovascular techniques are frequently employed to treat large artery occlusion in acute ischemic stroke (AIS). We sought to determine the predictors and clinical impact of intracranial hemorrhage (ICH) after endovascular therapy.

METHODS

Retrospective analysis of consecutive patients presenting to 13 high volume stroke centers with AIS due to proximal occlusion in the anterior circulation who underwent endovascular treatment within 8 h from symptom onset. Logistic regression was performed to determine the variables associated with ICH, hemorrhagic infarction (HI), and parenchymal hematomas (PHs), as well as 90 day poor outcome (modified Rankin Scale score ≥3) and mortality.

RESULTS

There were a total of 363 ICHs (overall rate 32.3%; HI=267, 24%; PH=96, 8.5%) among the 1122 study patients (mean age 67±15 years; median National Institutes of Health Stroke Scale score 17 (IQR 13-20)). Independent predictors for HI included diabetes mellitus (OR 2.27, 95% CI (1.58 to 3.26), p<0.0001), preprocedure IV tissue plasminogen activator (tPA) (1.43 (1.03 to 2.08), p<0.037), Merci thrombectomy (1.47 (1.02 to 2.12), p<0.032), and longer time to puncture (1.001 (1.00 to 1.002), p<0.026). Patients with atrial fibrillation (1.61 (1.01 to 2.55), p<0.045) had a higher risk of PH while the use of IA tPA (0.57 (0.35 to 0.90), p<0.008) was associated with lower chances of PH. Both the presence of HI (2.23 (1.53 to 3.25), p<0.0001) and PH (6.24 (3.06 to 12.75), p<0.0001) were associated with poor functional outcomes; however, only PH was associated with higher mortality (3.53 (2.19 to 5.68), p<0.0001).

CONCLUSIONS

Greater understanding about the predictors and consequences of ICH post endovascular stroke therapy is essential to improve risk assessment, patient selection/clinical outcomes, and early prognostication. Our data suggest that patients with atrial fibrillation are particularly prone to severe ICH and question the 'benign' nature of HI suggested by earlier studies.

Outcome of mechanical thrombectomy with Solitaire stent as first-line intra-arterial treatment in intracranial internal carotid artery occlusion

INTRODUCTION

Acute stroke from occlusion of the intracranial internal carotid artery (ICA) is associated with a poor clinical outcome despite a thrombolytic treatment. The purpose of this study was to evaluate the outcome of mechanical thrombectomy using the Solitaire stent for the treatment of acute stroke patients with intracranial ICA occlusion.

METHODS

A total of 104 consecutive patients with acute stroke were treated with mechanical thrombectomy using the Solitaire stent as a first-line intra-arterial treatment. We retrospectively reviewed data from 26 of these patients who presented with acute stroke attributable to intracranial ICA occlusion. Rescue treatments in cases of failed Solitaire thrombectomy included intra-arterial urokinase, angioplasty, and forced suction thrombectomy. Successful recanalization was defined as thrombolysis in cerebral ischemia grades 2b to 3. Outcome measure was the modified Rankin Scale (mRS) score of 0-2 at 3 months.

RESULTS

Successful recanalization was achieved in 77% (20/26) of patients. Recanalization was achieved with the Solitaire stent alone in 69% (18/26) of patients. Ten patients (39%) had a good clinical outcome (mRS score of 0-2) at 3 months. There was a good outcome in 50% of patients (10/20) with recanalization and no good outcome in patients (0/6) without recanalization (P = 0.027). None of eight patients who received rescue treatments showed a good outcome. No symptomatic intracerebral hemorrhage occurred. Mortality was 8% (2/26) at 3 months.

CONCLUSION

Mechanical thrombectomy using the Solitaire stent can achieve a high rate of successful recanalization and a very low rate of symptomatic hemorrhage and thus improve a clinical outcome in patients with acute intracranial ICA occlusion.

Predictive value of flat-panel CT for haemorrhagic transformations in patients with acute stroke treated with thrombectomy

INTRODUCTION

Haemorrhagic transformations are pejorative for patients with acute ischaemic stroke (AIS). We estimated flat-panel CT performances to detect brain parenchymal hyperdense lesions immediately after mechanical thrombectomy directly on the angiography table in patients with AIS, and its ability to predict haemorrhagic transformation. We also evaluated an easy-reading protocol for post-procedure flat-panel CT evaluation by clinicians to enable them to determine the potential risk of haemorrhage.

METHODS

Two neuroradiologists retrospectively reviewed post-procedural flat-panel CT and 24 h follow-up imaging. We evaluated hyperdense lesions on flat-panel CT to predict the occurrence of haemorrhagic transformation within 24 h detected with conventional imaging.

RESULTS

Of 63 patients, 60.3% presented post-procedural parenchymal hyperdensity and 54.0% had haemorrhagic transformation. Significantly more patients with hyperdense lesions on post-thrombectomy flat-panel CT presented haemorrhagic transformation (84.2% vs 8.0%; p<0.0001). No significant haemorrhagic transformations were detected for patients without parenchymal hyperdensity. Sensitivity and specificity of hyperdense lesions on flat-panel CT for the prediction of haemorrhagic transformation were 94.1% (80.3-99.3%) and 79.3% (60.3-92.0%), respectively. The positive and negative predictive values for the occurrence of haemorrhage were 84.2% (68.8-94.0%) and 92.0% (74.0-99.0%), respectively. For significant parenchymal haemorrhage type 2, sensitivity and negative predictive values were 100%. We observed good homogeneity between the different readers. Hyperdensity on post-procedural flat-panel CT was associated with a tendency for higher risk of death and lower risk of good clinical outcome.

CONCLUSIONS

Flat-panel CT appears to be a good tool to detect brain parenchymal hyperdensities after mechanical thrombectomy in patients with AIS and to predict haemorrhagic transformation.

Recanalization following various endovascular modalities for treatment of anterior circulation acute ischemic strokes

Currently several endovascular modalities and devices are available for use in acute ischemic stroke setting. Limited data exist regarding the relative efficacy of these different options when used individually or in combination. The primary objective of this study was to retrospectively compare the recanalization rates of various endovascular options when used for the treatment of acute ischemic stroke in the anterior cerebral circulation. We retrospectively reviewed 132 consecutive patients treated endovascularly at our center for acute ischemic stroke in the anterior cerebral circulation. Recanalization was defined as mTIMI of ≥ 2 while complete recanalization was defined as mTIMI of 4. Statistical analysis was performed to determine the modality or combination of modalities associated with best recanalization rate. Recanalization was achieved in 74% of patients while complete recanalization was achieved in 39% of patients. No individual endovascular therapy was significantly different from others in achieving recanalization. Where a multimodality approach was used, combination of angioplasty with intra- or extracranial stent placement was significantly (p=0.05) associated with recanalization. On regression analysis, combination of intra-arterial tPA with a mechanical modality (p=0.09) was significantly associated with recanalization while combination of intravenous tPA with intracranial stent placement (p=0.06) was significantly associated with complete recanalization. Combination of pharmacological and mechanical modalities in the setting of multimodal therapy is associated with increased likelihood of successful recanalization in patients with acute ischemic stroke in the anterior cerebral circulation. Stent placement in acute stroke setting is promising and needs further exploration. Further prospective studies are needed.

Endovascular management in patients with acute basilar artery obstruction: low-dose intra-arterial urokinase and mechanical clot disruption

Mechanical clot disruption for the treatment of acute basilar artery occlusion (BAO) is known to provide a benefit. We aimed to determine the safety, recanalization rate and time-to-flow restoration of mechanical clot disruption and low dose urokinase (UK) infusions for the treatment of patients with acute BAO. Between June 2006 and June 2010, 21 patients with acute BAO underwent endovascular treatment that included angioplasty or stent placement. The time to treatment, duration of the procedure, dose of urokinase (UK), recanalization rates and symptomatic hemorrhages were analyzed. Clinical outcome measures were assessed at admission and at the time of discharge using the National Institutes of Health Stroke Scale (NIHSS) score and at three months after treatment using the modified Rankin Score (mRS). On admission, the median NIHSS score was 13.2. Median time from symptom onset to arrival at hospital was 356 minutes, and median time from symptom onset to intraarterial thrombolysis (IAT) was 49 minutes. We used the following interventional treatment regimens: Intra-arterial (IA) UK and a minimal mechanical procedure (n=14), IA UK with angioplasty (n=1), IA UK with angioplasty and stent placement (n=3) and IA UK with HyperForm (n=3). The recanalization (thrombolysis in cerebral ischemia grade II or III) rate was 90.5% (19/21). There was symptomatic hemorrhage in one patient (4.8%). The median NIHSS score at discharge was 6.3. The three-month outcome was favorable (mRS: 0-2) for 14 patients (66.7%) and poor (mRS: 3-6) for seven patients (33.3%). The overall mortality at three months was 14.3% (three patients died). Low-dose IAT with mechanical clot disruption is a safe and effective treatment for treatment for acute BAO.

Intravenous Glycoprotein IIb/IIIa Inhibitor (Tirofiban) Followed by Low-Dose Intra-Arterial Urokinase and Mechanical Thrombolysis for the Treatment of Acute Stroke

We investigated the efficacy and safety of the combined use of IV tirofiban and IA urokinase and/or mechanical thrombolysis for treating acute stroke patients. Thirteen, consecutive patients treated with IV tirofiban and IA thrombolysis with mechanical and/or local IA urokinase infusion were evaluated retrospectively. The amount of time before the beginning of treatment, urokinase dose, recanalization rates, and symptomatic hemorrhage were analyzed. Clinical outcome measures were assessed on admission, at discharge (National Institute of Health Stroke scale [NIHSS]), and three months after the end of their treatment (modified Rankin Scale scores [mRS]). There were 11 patients with internal carotid or middle cerebral artery occlusion treated within six hours of the onset of symptoms and two patients with basilar artery occlusion treated within 12 hours of their symptom onset. The median NIHSS score on admission was 18. The median amount of time from symptom onset to IV tirofiban infusion was 135 minutes, and the median time from symptom onset to IA therapy was 180 minutes. The median dose of urokinase was 200,000 U. Recanalization (thrombolysis in myocardial infarction grade 2 or 3) was achieved in 11 patients. No procedure-related complications were observed. There was one symptomatic hemorrhage. At discharge, the mean NIHSS score was 6.6 (range, 0-15). Overall, at the time of the three-month follow-up the functional outcome was favorable (modified Rankin Scale score 0-2) in eight out of 13 (62%) patients. Death at 90 days occurred in two of the 13 (15%) patients. Combined IV tirofiban and IA thrombolysis with mechanical clot disruption seems to be a feasible treatment in acute stroke and may be successful in re-establishing vessel patency and result in a good functional outcome in patients with major cerebral arteries occlusions.

Hyperdensity on non-contrast CT immediately after intra-arterial revascularization

Non-contrast enhanced computed tomography (NCCT) is usually performed to estimate bleeding complications immediately after procedures. However, hyperdense areas on NCCT have not yet been understood; different interpretations have been reported in the literature. It remains unclear whether NCCT performed immediately after intra-arterial revascularization (IAR) could be useful for predicting hemorrhagic transformation (HT) or clinical outcomes. Therefore, we investigated the diagnostic values of hyperdense areas on NCCT images obtained immediately after IAR. This was a retrospective study of acute ischemic stroke patients who underwent IAR between October 2007 and December 2010. NCCT scans were routinely obtained immediately after IAR and additional follow-up imaging protocols included diffusion weighted imaging (DWI)/gradient echo imaging (GRE) 24 h after IAR. HT was assessed by means of GRE obtained 24 h after IAR. Hounsfield Unit (HU) of the hyperdensity was measured in the manually drawn regions of interest. A total of 68 patients were analyzed in this study. Twenty-nine patients (42.6%) developed HT on follow-up images. Thirty-eight patients had hyperdense areas on NCCT immediately after IAR. Hyperdensity on NCCT performed immediately after IAR revealed 23 (60.5%) of the 38 patients with six false negative areas. NCCT performed immediately after IAR showed a sensitivity of 79.3%, a specificity of 61.5%, a positive predictive value of 60.5% and a negative predictive value of 80% for HT. The HU value was a predictor of HT without statistical significance (area under curve of 0.629; 95% CI: 0.49-0.76; p = 0.068). In addition, an HU of >90 poorly predicted HT with a low sensitivity (23%) and a high specificity (94%). In conclusion, our results showed that although hyperdensity on NCCT images obtained immediately after IAR had a moderate predictive value for HT, there were limitations to the prediction of subsequent parenchymal hematoma and symptomatic intracranial hemorrhage, with a low specificity and a low positive predictive value.

A retrieval thrombectomy technique with the Solitaire stent in a large cerebral artery occlusion

BACKGROUND

To describe preliminary experiences and the procedural details of retrieval thrombectomy using a self-expanding and fully retrievable Solitaire stent (ev 3 Inc., CA, USA) in acute ischemic stroke (AIS) patients with large artery occlusions.

METHODS

Eight patients with AIS were treated by mechanical thrombectomy using a self-expanding, fully retrievable stent (Solitaire, ev 3 Inc., CA, USA). The stent was deployed to cover the whole intra-arterial clot and then it was slowly retrieved while occluding the internal cerebral artery (ICA) with a balloon guiding catheter. Additionally, continuous negative pressure was applied through the balloon guiding catheter with a specially designed gun device. Occlusion sites were M1 in six cases including one combined supraclinoid ICA occlusion and the other combined M2 occlusion, M2 in 1 case and one basilar artery top.

RESULTS

Complete recanalization was achieved in all patients. Procedure time was 45 min or less in seven cases and 70 min in one case. Distal emboli occurred in one case in which the balloon guide catheter was not used. Only in this case was intraarterial fibrinolytics infusion necessary. There was no post-operative intracranial hemorrhage.

CONCLUSIONS

In our experience, retrieval thrombectomy with the Solitaire stent was a simple and effective method for reopening large cerebral arteries in AIS patients.

Contrast stasis on noncontrast computed tomography as a predictor of stroke postthrombolysis

Multimodal endovascular intervention is becoming more commonplace for the acute intervention of ischemic stroke. Hyperdensity in a portion of the treated territory is a common finding on postthrombolytic noncontrast CT (NCCT), but its significance is poorly understood. The authors conducted a single-institution, retrospective chart review of patients who had intraarterial thrombolysis of the anterior circulation between 2010 and 2011 with evidence of hyperdensity on NCCT following recanalization. Eighteen patients had evidence of postoperative contrast stasis causing hyperdensity on NCCT. One hundred percent of the patients had MR imaging evidence of completed strokes postoperatively in the same distribution as the stasis. Stasis on NCCT after intervention had a sensitivity and specificity of 82% and 0% for predicting stroke, respectively. Furthermore, the positive predictive value was 100%. The presence of contrast stasis on postthrombolytic NCCT correlates well with stroke seen on subsequent MR imaging.

Usefulness of MRA-DWI mismatch in neuroendovascular therapy for acute cerebral infarction

BACKGROUND

This study evaluated the usefulness of MR angiography (MRA)-diffusion-weighted imaging (DWI) mismatch in neuroendovascular therapy over 3 h after onset of acute cerebral infarction.

METHODS

The subjects were 14 cases (age, 73 ± 8.4 years) who had an anterior circulation deficit on DWI/MRA on arrival and underwent neuroendovascular therapy over 3 h after onset. MRA-DWI mismatch (MDM) (+) was defined as 'major artery lesion (+) and diffusion-weighted image-Alberta Stroke Program Early CT Score (DWI-ASPECTS) ≥6'; MDM (-) was defined as 'major artery lesion (+) and DWI-ASPECTS <6'.

RESULTS

Reperfusion was achieved in nine of 14 patients (64%) undergoing neuroendovascular therapy. Within the reperfusion group, in the five MDM (+) patients and the four MDM (-) patients, the outcome was a favorable clinical response in the MDM (+) group. The modified Rankin Scale (mRS) scores after 90 days were 0-2 in 3 (60%) and 3-6 in 2 (40%) of the MDM (+) group patients and 0-2 in 0 (0%) and 3-6 in 4 (100%) of the MDM (-) group patients. In the MDM (+) group, a good outcome was achieved. However, the number of cases was small, so this was not a significant difference. Within the non-reperfusion group, in the three MDM (+) patients and the two MDM (-) patients, the mRS scores after 90 days were 0-2 in 1 (33%) and 3-6 in 2 (67%) of the MDM (+) group patients and 0-2 in 0 (0%) and 3-6 in 2 (100%) of the MDM (-) group patients. In both groups, the outcome was poor.

CONCLUSIONS

With neuroendovascular therapy, a good outcome with reperfusion was achieved in the MDM (+) group compared to the MDM (-) group. This suggests that the presence or absence of MDM may be useful in determining prognosis after reperfusion.

Safety of high doses of urokinase and reteplase for acute ischemic stroke

BACKGROUND AND PURPOSE

ET is considered in selected patients with AIS with persistent arterial occlusion after receiving IVT. Limited data exist on the safety of IA high doses of UK and RT for ET. We investigated any correlation between IA doses of UK or RT and safety outcomes in patients who underwent ET.

MATERIALS AND METHODS

We identified all patients from our stroke registry who received UK or RT for ET from 1998 to 2008. Demographics, baseline National Institutes of Health Stroke Scale scores, recanalization rates, rates of attempted MT, mortality, SICH, and discharge modified Rankin Scale scores were collected.

RESULTS

Of 197 patients; 72 received UK and 125 received RT. More than 90% of patients in both groups had received prior IVT. The median IA dose of UK was 200,000 U (range, 25,000-1,500,000 U) and of RT was 2 mg (range, 1-8 mg). Concurrent MT was attempted in 59.7% of UK-treated patients and 72.0% of RT-treated patients, with SICH rates of 4.2% and 8.0%, respectively. Logistic regression adjusting for prior IVT and MT revealed no correlation between SICH and doses of UK (OR, 1.00; 95% CI, 0.99-1.00; P = .94) or RT (OR, 0.803; 95% CI, 0.48-1.33; P = .39). There was no correlation between mortality and doses of UK (OR, 1.00; 95% CI, 0.99-1.00; P = .51) or RT (OR, 1.048; 95% CI, 0.77-1.42; P = .75).

CONCLUSIONS

High IA doses of UK and RT may be safe when given with or without MT in patients with AIS despite receiving a full dose of intravenous recombinant tissue plasminogen activator. These results need prospective validation.

Intravenous Glycoprotein IIb/IIIa inhibitor (Tirofiban) Followed by Low-dose Intra-arterial Urokinase and Mechanical Thrombolysis for the Treatment of Stroke

We investigated the efficacy and safety of the combined use of IV tirofiban and IA urokinase and/or mechanical thrombolysis for treating acute stroke patients. Thirteen, consecutive patients who were treated with IV tirofiban and IA thrombolysis with mechanical and/or local IA urokinase infusion, were evaluated retrospectively. The amount of time before the beginning of treatment, urokinase dose, recanalization rates, and symptomatic hemorrhage were analyzed. Clinical outcome measures were assessed on admission, at discharge (National Institute of Health Stroke scale[NIHASS]), and three months after the end of their treatment (modified Rankin Scale scores[mRS]). There were 11 patients with internal carotid or middle cerebral artery occlusion treated within six hours of the onset of symptoms and two patients with basilar artery occlusion treated within 12 hours of their symptom onset. The median NIHSS score on admission was 18. The median amount of time from symptom onset to IV tirofiban infusion was 135 minutes, and the median time from symptom onset to IA therapy was 180 minutes. The median dose of urokinase was 200,000 U. Recanalization (thrombolysis in myocardial infarction grade 2 or 3) was achieved in 11 patients. No procedure-related complications were observed. There was one symptomatic hemorrhage. At discharge, the mean NIHSS score was 6.6 (range, 0- 15). Overall, at the time of the three-month follow-up the functional outcome was favorable (modified Rankin Scale score 0 -2) in eight of 13 (62%) patients. Death at 90 days occurred in two of the 13 (15%) patients. Combined IV tirofiban and IA thrombolysis with mechanical clot disruption seems to be a feasible treatment in acute stroke and may be successful in reestablishing vessel patency and result in a good functional outcome in patients with major cerebral arteries occlusions.

Predictors of subarachnoid hemorrhage in acute ischemic stroke with endovascular therapy

BACKGROUND AND PURPOSE

Subarachnoid hemorrhage (SAH) is a potential hemorrhagic complication after endovascular intracranial recanalization. The purpose of this study was to describe the frequency and predictors of SAH in acute ischemic stroke patients treated endovascularly and its impact on clinical outcome.

METHODS

Acute ischemic stroke patients treated with primary mechanical thrombectomy, intra-arterial thrombolysis, or both were analyzed. Postprocedural computed tomography and magnetic resonance images were reviewed to identify the presence of SAH. We assessed any decline in the National Institutes of Health Stroke Scale score 3 hours after intervention and in the outcomes at discharge.

RESULTS

One hundred twenty-eight patients were treated by primary thrombectomy with MERCI Retriever devices, whereas 31 were treated by primary intra-arterial thrombolysis. Twenty patients experienced SAH, 8 with pure SAH and 12 with coexisting parenchymal hemorrhages. SAH was numerically more frequent with primary thrombectomy than in the intra-arterial thrombolysis groups (14.1% vs 6.5%, P = 0.37). On multivariate analysis, independent predictors of SAH were hypertension (odds ratio = 5.39, P = 0.035), distal middle cerebral artery occlusion (odds ratio = 3.53, P = 0.027), use of rescue angioplasty after thrombectomy (odds ratio = 12.49, P = 0.004), and procedure-related vessel perforation (odds ratio = 30.72, P < 0.001). Patients with extensive SAH or coexisting parenchymal hematomas tended to have more neurologic deterioration at 3 hours (28.6% vs 0%, P = 0.11), to be less independent at discharge (modified Rankin Scale ≤ 2; 0% vs 15.4%, P = 0.5), and to experience higher mortality during hospitalization (42.9% vs 15.4%, P = 0.29).

CONCLUSIONS

Procedure-related vessel perforation, rescue angioplasty after thrombectomy with MERCI devices, distal middle cerebral artery occlusion, and hypertension were independent predictors of SAH after endovascular therapy for acute ischemic stroke. Only extensive SAH or SAH accompanied by severe parenchymal hematomas may worsen clinical outcome at discharge.

Endovascular treatment of acute ischemic stroke may be safely performed with no time window limit in appropriately selected patients

BACKGROUND AND PURPOSE

The traditional time window for acute ischemic stroke intra-arterial therapy (IAT) is <6 hours, which is based on pharmacological thrombolysis without penumbral imaging. This study was conducted to determine the safety of patient selection for IAT based on perfusion mismatch rather than time.

METHODS

A cohort of consecutive patients treated with IAT was identified by database review. Patients were selected for IAT based on the presence of perfusion mismatch using CT perfusion or MRI regardless of stroke duration. Thrombolytics were minimized after 6 hours in favor of mechanical embolectomy or angioplasty+/-stenting. Outcomes (National Institutes of Health Stroke Scale, modified Rankin Scale) were assessed by independent examiners. A multivariate analysis was performed to compare those treated <6 hours (early) with those treated >6 hours (late).

RESULTS

Fifty-five patients (mean National Institutes of Health Stroke Scale=19.7+/-5.7) were treated, 34 early and 21 late, with mean time-to-intervention of 3.4+/-1.6 hours and 18.6+/-16.0 hours, respectively. Thrombolysis In Myocardial Ischemia 2 or 3 recanalization was achieved in 82.8% early and 85.7% late patients (P=1.0). Intracerebral hemorrhage occurred in 25.5% overall, but symptomatic intracerebral hemorrhage occurred in 8.8% of the early and 9.5% of the late patients (P=1.0). Thirty-day mortality was similar (29.4% versus 23.8%, P=0.650). At 3 months, 41.2% and 42.9%, respectively, achieved a modified Rankin Scale <or=2 (P=0.902). Only presenting National Institutes of Health Stroke Scale was a predictor of modified Rankin Scale <or=2 (OR 0.794[95% CI 0.68 to 0.92], P=0.009) and death (adjusted OR 1.29[95% CI 1.04 to 1.59], P=0.019).

CONCLUSIONS

In appropriately selected patients, IAT for acute ischemic stroke can be performed safely regardless of stroke duration. The concept of an acute ischemic stroke treatment window for IAT should be re-evaluated with a clinical trial selecting patients with perfusion mismatch.

Acute endovascular stroke therapy

The burden of ischemic stroke in the United States continues to increase each year. Patients with stroke with the most severe disability require a disproportionately large share of healthcare resources. Acute endovascular stroke therapy has the potential to reduce the disability associated with large vessel occlusions and diminish the tremendous economic and emotional burden. This article serves to provide a backdrop on acute stroke therapy focusing on the role, limitations, and benefits of an endovascular approach. We review the rationale, current literature, and future directions of mechanical devices for stroke thrombolysis. We also review pertinent issues related to thrombolysis-related intracerebral hemorrhage and appropriate patient selection.

Conscious Sedation Versus General Anesthesia During Endovascular Therapy for Acute Anterior Circulation Stroke

Background and Purpose— Patients undergoing intra-arterial therapy (IAT) for acute ischemic stroke receive either general anesthesia (GA) or conscious sedation. GA may delay time to treatment, whereas conscious sedation may result in patient movement and compromise the safety of the procedure. We sought to determine whether there were differences in safety and outcomes in GA patients before initiation of IAT.

Methods— A cohort of 980 patients at 12 stroke centers underwent IAT for acute stroke between 2005 and 2009. Only patients with anterior circulation strokes due to large-vessel occlusion were included in the study. A binary logistic-regression model was used to determine independent predictors of good outcome and death.

Results— The mean age was 66±15 years and median National Institutes of Health Stroke Scale score was 17 (interquartile range, 13–20). The overall recanalization rate was 68% and the symptomatic hemorrhage rate was 9.2%. GA was used in 44% of patients with no differences in intracranial hemorrhage rates when compared with the conscious sedation group. The use of GA was associated with poorer neurologic outcome at 90 days (odds ratio=2.33; 95% CI, 1.63–3.44; P <0.0001) and higher mortality (odds ratio=1.68; 95% CI, 1.23–2.30; P <0.0001) compared with conscious sedation.

Conclusions— Patients placed under GA during IAT for anterior circulation stroke appear to have a higher chance of poor neurologic outcome and mortality. There do not appear to be differences in hemorrhagic complications between the 2 groups. Future clinical trials with IAT can help elucidate the etiology of the differences in outcomes.

Neuroendovascular management of acute ischemic stroke

Endovascular reperfusion therapy is evolving as a promising treatment in the setting of acute ischemic stroke. Careful patient selection and angiographic evaluation of the location and extent of occlusion are necessary for the successful management of stroke patients. Intra-arterial chemical thrombolysis, with such agents as alteplase and urokinase, has shown favorable results in the early management of cerebrovascular ischemia. Mechanical thrombolysis is becoming an adjunctive or alternative treatment therapy via novel clot dissolution and retrieval techniques. Existing and upcoming trials are investigating the safety and efficacy of neuroendovascular therapy while attempting to expand its indications in acute ischemic stroke.

Impact of baseline tissue status (diffusion-weighted imaging lesion) versus perfusion status (severity of hypoperfusion) on hemorrhagic transformation

BACKGROUND AND PURPOSE

The frequency of hemorrhagic transformation (HT) on gradient echo imaging and its impact on stroke outcomes continues to be debated. We investigated the factors associated with HTs and the influence of the HTs observed on gradient echo imaging on the early course after a stroke.

METHODS

We analyzed the data from a prospectively maintained registry of patients who were eligible for recanalization therapy. Serial diffusion-weighted imaging and perfusion-weighted imaging were performed, and HTs were assessed on follow-up gradient echo imaging. Tmax perfusion lesion maps were generated and hypoperfused regions were divided into severe (Tmax >or=8 seconds) delay and mild (Tmax >or=2 seconds but Tmax <8 seconds) delay. The factors associated with HTs, including the mode of recanalization therapy, pretreatment diffusion-weighted imaging and perfusion-weighted imaging lesion volumes, and reperfusion indices, were evaluated. The early clinical outcome was assessed during the first 7 days of admission.

RESULTS

A total of 184 patients were included in this study. HTs were noted in 73 (39.7%) patients. Multiple logistic regression analysis identified aggressive treatment (OR, 5.12; 95% CI, 1.73 to 15.18) and a large area of severe perfusion delay (OR for highest quartile of Tmax >8 seconds, 12.91; 95% CI, 3.69 to 45.17) as independent predictors of HTs. Neither risk factor profiles nor diffusion-weighted imaging lesion volumes were associated with HTs. There was a poor correlation between the radiological (HT types) and clinical (asymptomatic or symptomatic) categories of HTs. Even a parenchymal hematoma was not always associated with symptomatic worsening or affected the early clinical outcomes.

CONCLUSIONS

The results of this study indicate that the perfusion status (severe perfusion delay) rather than the tissue status (diffusion-weighted imaging lesions) and aggressive treatment were independently associated with HTs. HT on gradient echo imaging was common but usually associated with severe hypoperfusion and not always associated with clinical deterioration.

Low-dose intra-arterial urokinase and aggressive mechanical clot disruption for acute ischemic stroke after failure of intravenous thrombolysis

BACKGROUND AND PURPOSE

Intravenous (IV) thrombolysis often fails to achieve recanalization of occluded cerebral arteries, especially in patients with proximal large arterial occlusions. The goal of this study was to assess the feasibility, safety, and efficacy of low-dose intra-arterial (IA) urokinase and aggressive mechanical clot disruption (AMCD) after failure of IV thrombolysis for acute ischemic stroke.

MATERIALS AND METHODS

We prospectively enrolled 12 patients with acute ischemic stroke who initially received IV recombinant tissue plasminogen activator (rtPA) and were subsequently treated with combined low-dose IA urokinase and AMCD. Time to treatment, urokinase dose, duration of the procedure, recanalization rates, and symptomatic hemorrhage were analyzed. Clinical outcome measures were assessed on admission and at discharge (National Institutes of Health Stroke Scale [NIHSS]), and at 3 months after treatment (modified Rankin Scale [mRS]).

RESULTS

Median NIHSS score on admission was 17. Median time from symptom onset to IV rtPA was 120 minutes, and median time from symptom onset to IA therapy was 230 minutes. The median duration of IA therapy was 55 minutes. Median dose of urokinase was 300,000 U. Recanalization (thrombolysis in cerebral ischemia grade II or III) was achieved in all patients. No procedure-related complications were observed. There was no symptomatic hemorrhage. At discharge, median NIHSS score was 3. The 3-month outcome was excellent (mRS, 0-1) in 8 patients, good (mRS, 2) in 1 patient, and poor (mRS, 3-5) in 3 patients. There was no hospital or 3-month mortality.

CONCLUSIONS

In this study, combination therapy with low-dose IA urokinase and AMCD is safe and effective after failed IV thrombolysis in patients with acute ischemic stroke. A high rate of recanalization, low rate of symptomatic hemorrhage, and excellent functional outcome can be achieved.

Computed tomography in acute ischemic stroke

Stroke remains the third most important cause of mortality in industrialized countries; this has prompted research for improvements in both diagnostic and therapeutic strategies for patients with signs of acute cerebral ischemia. Over the last decade, there has been a parallel in progress in techniques in both diagnostic and therapeutic options. While previously only used for excluding hemorrhage, imaging now has the possibility to detect ischemia, vascular occlusion, as well as detect tissue at risk in one setting. It should also allow to monitor treatment and predict/exclude therapeutic complications. Parallel to advances in magnetic resonance imaging of stroke, computed tomography has improved immensely over the last decade due to the development of CT scanners that are faster and that allow to acquire studies such as CT perfusion or CT angiography in a reliable way. CT can detect many signs that might help us detect impending signs of massive infarction, but we still lack the experience to use these alone to prevent a patient from benefitting from possible therapy.

Mechanical Approaches Combined With Intra-Arterial Pharmacological Therapy Are Associated With Higher Recanalization Rates Than Either Intervention Alone in Revascularization of Acute Carotid Terminus Occlusion

Background and Purpose— Acute stroke attributable to internal carotid artery terminus occlusion carries a poor prognosis. Vessel recanalization is crucial to improve clinical outcome. Historically, pharmacological thrombolysis alone has low recanalization rates. We sought to determine whether adjunctive mechanical approaches achieve better vessel recanalization and functional outcome.

Methods— We retrospectively reviewed 75 consecutive endovascular cases of acute internal carotid artery terminus occlusions treated at our center between 1998 and 2008. Mechanical approaches (MERCI retrieval/angioplasty/stent) with and without adjunctive intra-arterial pharmacological therapy (urokinase or tissue plasminogen activator) was compared to intra-arterial lytics alone. Univariate and multivariate analyses were performed to determine predictors of recanalization (thrombolysis in myocardial infarction grades 2 to 3) and favorable functional outcome (modified Rankin score ≤2) at 3 months.

Results— Lowest recanalization rates were observed with intra-arterial lytics alone (3/17, 17.6%). MERCI embolectomy combined with intra-arterial lytics was associated with the highest recanalization rates (18/21, 85.7%; P <0.0001). MERCI embolectomy alone achieved 46.2% recanalization rates (6/13; P =0.23). Angioplasty or stenting and intra-arterial lytics achieved 25% (2/8; P =0.65) and 40% (4/10; P =0.085) recanalization, respectively. In multivariate analysis, combination of MERCI embolectomy with intra-arterial lytics (OR, 16.2; CI, 4.6–77.6), or any mechanical technique with intra-arterial lytics (OR, 6.7; CI, 2.5–19.5) independently predicted thrombolysis in myocardial infarction 2 to 3 recanalization. Clinically significant parenchymal hemorrhage rates were 7.5% with combination (3/38) and 12.5% with pharmacological therapies (2/16; P =0.46). Using stepwise logistic regression, age (OR, 0.95; CI, 0.90–0.995), baseline NIHSS (OR, 0.82; CI, 0.70–0.96), and thrombolysis in myocardial infarction 2 to 3 recanalization (OR, 4.0; CI, 1.1–14.4) were associated with favorable functional outcome.

Conclusions— Combined mechanical and intra-arterial pharmacological therapy is associated with higher recanalization rates than either intervention alone in acute internal carotid artery terminus occlusion revascularization.

Evaluation of perfusion CT and TIBI grade in acute stroke for predicting thrombolysis benefit and clinical outcome

OBJECTIVE

To evaluate the prognostic accuracy of combining perfusion CT (PCT) and thrombolysis in brain ischemia (TIBI) ultrasonographic grade in the triage of stroke patients who will benefit from thrombolysis and in predicting the clinical outcome.

METHODS

We conducted a prospective study of all consecutive stroke patients admitted to our hospital from March 2003 to July 2007, presenting with signs of acute stroke within the therapeutic window, who had undergone either intravenous or combined intravenous and intra-arterial thrombolysis. All patients were evaluated by a complete stroke CT protocol, transcranial color-coded duplex sonographic monitoring, follow-up imaging (CT or MRI) and clinical outcome at 3 months, as assessed by the modified Rankin scale (mRS).

RESULTS

A total of 34 patients were included with a mean NIHSS on admission of 14.2. This study revealed that PCT had 95% sensitivity and 71% specificity in the evaluation of therapy benefit as well as 75% sensitivity and 39% specificity in predicting clinical outcome. The extent of ischemic tissue according to PCT and TIBI grade were significantly correlated (p<0.05). Using the MTT-TTP approach was an alternative to the classical MTT-CBV approach for determining tissue at risk. The clinical outcome assessed by the mRS was considered favorable (mRS 0-2) in 16 patients and unfavorable (mRS>2) in 18 patients.

CONCLUSION

PCT was the most accurate predictor of both thrombolytic therapy benefit and clinical outcome. The TIBI score was useful for determining whether or not to perform intravenous therapy alone or as a combined therapy.

LOWER PRETREATMENT CEREBRAL BLOOD VOLUME AFFECTS HEMORRHAGIC RISKS AFTER INTRA-ARTERIAL REVASCULARIZATION IN ACUTE STROKE

OBJECTIVE

Intra-arterial therapies are being used more frequently in patients presenting with acute cerebral occlusions, but they have been limited by the potential for hemorrhage. We sought to determine whether pretreatment computed tomography perfusion parameters might help to identify patients at a higher risk of developing intracranial hemorrhage after intra-arterial stroke revascularization treatment.

METHODS

We retrospectively reviewed all patients at the University of Pittsburgh Medical Center and Michigan State University who underwent computed tomography perfusion imaging of the brain before intra-arterial thrombolysis between January 2006 and June 2007. Demographic information, angiographic variables, and types of endovascular interventions were recorded. The mean transit time and cerebral blood volumes were recorded for the ipsilateral and contralateral middle cerebral artery territories. A binary logistic regression model was constructed to determine the independent predictors of developing intracranial hemorrhage.

RESULTS

A total of 57 patients (33 from the University of Pittsburgh and 24 from Michigan State University) with a mean age of 66 ± 13 years and mean National Institutes of Health Stroke Scale scores of 16 ± 5 were studied. The overall recanalization (Thrombolysis in Myocardial Infarction Trial scale 2 or 3 flow) was 72% for the cohort, and the overall rate of parenchymal hemorrhage was 5 of 57 (9%) patients. The overall hemorrhage rate was 19 of 57 (33%) patients. The only variable found to be predictive of the development of hemorrhage after intervention was reduced pretreatment cerebral blood volume (odds ratio, 0.49; 95% confidence interval, 0.35–0.91; P &lt; 0.022).

CONCLUSION

A reduced pretreatment ipsilateral cerebral blood volume value before endovascular revascularization of an acute middle cerebral artery or internal carotid artery occlusion significantly increases the risk of an intracranial hemorrhage.

Activation of PDGF-CC by tissue plasminogen activator impairs blood-brain barrier integrity during ischemic stroke

Thrombolytic treatment of ischemic stroke with tissue plasminogen activator (tPA) is markedly limited owing to concerns about hemorrhagic complications and the requirement that tPA be administered within 3 h of symptoms. Here we report that tPA activation of latent platelet-derived growth factor-CC (PDGF-CC) may explain these limitations. Intraventricular injection of tPA or active PDGF-CC, in the absence of ischemia, leads to significant increases in cerebrovascular permeability. In contrast, co-injection of neutralizing antibodies to PDGF-CC with tPA blocks this increased permeability, indicating that PDGF-CC is a downstream substrate of tPA within the neurovascular unit. These effects are mediated through activation of PDGF-alpha receptors (PDGFR-alpha) on perivascular astrocytes, and treatment of mice with the PDGFR-alpha antagonist imatinib after ischemic stroke reduces both cerebrovascular permeability and hemorrhagic complications associated with late administration of thrombolytic tPA. These data demonstrate that PDGF signaling regulates blood-brain barrier permeability and suggest potential new strategies for stroke treatment.

Recanalization between 1 and 24 hours after t-PA therapy is a strong predictor of cerebral hemorrhage in acute ischemic stroke patients

BACKGROUND AND PURPOSE

Intravenous administration of tissue plasminogen activator (t-PA) can improve clinical outcomes in patients with acute ischemic stroke. The most important complication of t-PA therapy is intracerebral hemorrhage (ICH). The aim of this study was to use serial MRI studies to identify independent predictors of symptomatic and asymptomatic ICH after t-PA therapy.

METHODS

Consecutive anterior-circulation ischemic stroke patients treated with t-PA within 3 h of stroke onset were studied prospectively. To identify the presence of recanalization in the occluded arteries and the presence of ICH, MRI, including diffusion weighted imaging (DWI), T2*, and magnetic resonance angiography (MRA), was performed before and 1 h, 24 h, and 5-7 days after t-PA thrombolysis. The independent predictors of ICH were determined using multivariate logistic regression analysis.

RESULTS

41 patients (21 males, 20 females; mean age, 73.2+/-10.7 years) were enrolled, and 19 ICHs (1 symptomatic, 18 asymptomatic) were observed on T2*. The initial MRA demonstrated occluded brain arteries in 31 patients (75.6%), of which follow-up MRA at 1 h, 24 h, and 5-7 days after t-PA therapy revealed recanalization in 48.4%, 80.0%, and 90.0% of patients, respectively. The frequency of recanalization within 1 h after t-PA therapy did not differ between ICH and No-ICH groups, but the ICH group had more frequent recanalization between 1 h and 24 h after t-PA than the No-ICH group (50.0% vs. 4.5%, P=0.001). The ICH group had arterial fibrillation (AF) more frequently than the No-ICH group (78.9% vs. 27.3%, P=0.001). Compared to the No-ICH group, the NIHSS score was higher (16.4+/-5.7 vs. 11.5+/-6.5, P=0.011) and the ASPECTS-DWI value (a normal DWI has an ASPECTS-DWI value of 11 points) was lower (7.3+/-2.4 vs. 8.9+/-1.9, P=0.019) in the ICH group. Multivariate logistic regression analysis demonstrated that the presence of recanalization between 1 and 24 h after the end of t-PA infusion (OR: 20.2; CI: 1.0-340.9; P=0.037) was the only independent predictor of ICH.

CONCLUSION

Recanalization of occluded arteries between 1 and 24 h but not within 1 h after t-PA infusion should be independently associated with symptomatic and asymptomatic ICH after t-PA therapy.