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

Effect of Intra-arterial Alteplase vs Placebo Following Successful Thrombectomy on Functional Outcomes in Patients With Large Vessel Occlusion Acute Ischemic Stroke: The CHOICE Randomized Clinical Trial

IMPORTANCE

It is estimated that only 27% of patients with acute ischemic stroke and large vessel occlusion who undergo successful reperfusion after mechanical thrombectomy are disability free at 90 days. An incomplete microcirculatory reperfusion might contribute to these suboptimal clinical benefits.

OBJECTIVE

To investigate whether treatment with adjunct intra-arterial alteplase after thrombectomy improves outcomes following reperfusion.

DESIGN, SETTING, AND PARTICIPANTS

Phase 2b randomized, double-blind, placebo-controlled trial performed from December 2018 through May 2021 in 7 stroke centers in Catalonia, Spain. The study included 121 patients with large vessel occlusion acute ischemic stroke treated with thrombectomy within 24 hours after stroke onset and with an expanded Treatment in Cerebral Ischemia angiographic score of 2b50 to 3.

INTERVENTIONS

Participants were randomized to receive intra-arterial alteplase (0.225 mg/kg; maximum dose, 22.5 mg) infused over 15 to 30 minutes (n = 61) or placebo (n = 52).

MAIN OUTCOMES AND MEASURES

The primary outcome was the difference in proportion of patients achieving a score of 0 or 1 on the 90-day modified Rankin Scale (range, 0 [no symptoms] to 6 [death]) in all patients treated as randomized. Safety outcomes included rate of symptomatic intracranial hemorrhage and death.

RESULTS

The study was terminated early for inability to maintain placebo availability and enrollment rate because of the COVID-19 pandemic. Of 1825 patients with acute ischemic stroke treated with thrombectomy at the 7 study sites, 748 (41%) patients fulfilled the angiographic criteria, 121 (7%) patients were randomized (mean age, 70.6 [SD, 13.7] years; 57 women [47%]), and 113 (6%) were treated as randomized. The proportion of participants with a modified Rankin Scale score of 0 or 1 at 90 days was 59.0% (36/61) with alteplase and 40.4% (21/52) with placebo (adjusted risk difference, 18.4%; 95% CI, 0.3%-36.4%; P = .047). The proportion of patients with symptomatic intracranial hemorrhage within 24 hours was 0% with alteplase and 3.8% with placebo (risk difference, -3.8%; 95% CI, -13.2% to 2.5%). Ninety-day mortality was 8% with alteplase and 15% with placebo (risk difference, -7.2%; 95% CI, -19.2% to 4.8%).

CONCLUSIONS AND RELEVANCE

Among patients with large vessel occlusion acute ischemic stroke and successful reperfusion following thrombectomy, the use of adjunct intra-arterial alteplase compared with placebo resulted in a greater likelihood of excellent neurological outcome at 90 days. However, because of study limitations, these findings should be interpreted as preliminary and require replication.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03876119; EudraCT Number: 2018-002195-40.

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.

Outcome of acute ischemic stroke after intra-arterial thrombolysis: A study from India

Background: Intravenous recombinant tissue plasminogen activator (rt-PA) is the currently standard treatment of acute ischemic stroke within 4.5 hours of the onset of stroke. Recent studies have looked at the benefits of administration of intra-arterial (IA) rt-PA within 8 hours onset of symptoms. Our objective was to assess the outcome of stroke after administration of IA rt-PA in patients with acute ischemic stroke. Methods: We recruited 10 consecutive acute ischemic stroke patients with onset of stroke from 4.5 hours to 6.5 hours. The present study was conducted at Yashoda Hospital, Hyderabad, India, between January 2008 and December 2013. All patients underwent stroke subtyping and were administered rt-PA. We measured the thrombolysis in cerebral infarction (TICI) score after thrombolysis and functional outcomes at time of admission, after 24 hours, 30, 60, and 90 days. A good outcome was defined as modified Rankin Scale (mRS) ≤ 2 after 90 days. Results: Out of 10 patients 9 were men, mean age 56.3 ± 1.8 years and age range from 35-68 years. On stroke subtyping, 6 (60%) patients had large artery atherosclerosis, 3 (30%) had a stroke of indeterminate etiology and 1 (10%) had a stroke of other etiologies. Mean time of recanalization was 6.2 ± 0.5 hours, 7 (70%) patients showed major neurological improvement with a mRS score of ≤ 2 at 90 days and one patient was lost to follow-up. Conclusion: Our study established good outcome at 90 days after administration of IA thrombolysis rt-PA in acute ischemic stroke.

Acute basilar artery occlusion: outcome of mechanical thrombectomy with Solitaire stent within 8 hours of stroke onset

BACKGROUND AND PURPOSE

Mechanical thrombectomy with a stent retriever applied shortly after symptom onset could increase good functional outcomes and improve survival in patients with acute basilar artery occlusion, but this has not yet been studied. This study evaluated the efficacy and safety of mechanical thrombectomy with a Solitaire stent within 8 hours of stroke onset in patients with acute basilar artery occlusion.

MATERIALS AND METHODS

We analyzed 25 consecutive patients with acute basilar artery occlusion who were treated with mechanical thrombectomy by use of the Solitaire stent within 8 hours of stroke symptom onset. Successful recanalization was defined as TICI grade 2b or 3. Good outcome was defined as mRS score of 0-2 at 3 months. Clinical and radiologic data in patients with good outcomes were compared with those with poor outcomes.

RESULTS

Successful recanalization was achieved in 96% (24/25) of patients, and 48% (12/25) of patients had good outcomes. Eighty-eight percent (22/25) of patients survived to 3 months. The median NIHSS score on admission was significantly lower in patients with good outcomes than in those with poor outcomes (9.5 versus 14, P = .005). Procedure-related complications occurred in 2 patients (8%). No symptomatic intracerebral hemorrhages occurred.

CONCLUSIONS

The current study suggests that mechanical thrombectomy by use of a Solitaire stent within 8 hours of stroke onset increases good outcomes and improves survival in patients with acute basilar artery occlusion.

Repeated thrombolytic therapy in patients with recurrent acute ischemic stroke

Background and Purpose

Widespread use of thrombolytic treatments, along with improved chances of survival after an initial ischemic stroke, increases the possibility of repeated thrombolysis. There are few reports, however, regarding repeated thrombolysis in patients who have suffered acute ischemic stroke. We explored the number and outcome of patients with repeated thrombolytic therapy in the era of multimodal thrombolytic treatments.

Methods

We investigated patients with acute ischemic stroke who had received thrombolytic treatments for a period of 10 years. Number of thrombolysis was determined in each patient. Recanalization was defined as Thrombolysis in Cerebral Infarction grading ≥2a. Symptomatic hemorrhagic transformation was defined as any increase in the National Institutes of Health Stroke Scale score that could be attributed to intracerebral hemorrhage. A good outcome was defined as a modified Rankin scale score ≤2.

Results

Of the 437 patients who received thrombolytic treatments, only 7 underwent repeated thrombolysis (1.6%). The median age at the time of repeated thrombolytic therapy was 71 years old; 4 of the patients were female. All patients had 1 or more potential sources of cardiac embolism. Recanalization was achieved in all patients, in both the first and the second thrombolysis. No symptomatic intracranial hemorrhage occurred after repeated thrombolytic treatments. Five patients (71.4%) showed good outcomes at 3 months.

Conclusions

Repeated thrombolysis for recurrent acute ischemic stroke appears to be safe and feasible. Among patients who experience recurrent acute ischemic stroke, thrombolytic therapy could be considered even if the patient has had previous thrombolytic treatments.

Recanalization of acute intracranial artery occlusion using temporary endovascular bypass technique

PURPOSE

The purpose of this study is to present our preliminary experience of the temporary endovascular bypass (TEB) technique using an Enterprise stent for recanalization of acute intracranial artery (IA) occlusion.

MATERIALS AND METHODS

Patients treated by TEB were enrolled in this retrospective study from January 2009 to May 2010. All the procedures consist of temporary partial deployment and subsequent retrieval of Enterprise stent, supplemented by intra-arterial infusion of urokinase (UK) and/or tirofiban. According to the thrombolysis in cerebral infarction (TICI) classification, recanalization was evaluated with initial and postprocedural angiography. Safety was evaluated related to the procedure and clinical outcomes were assessed by National Institute of Health Stroke Scale (NIHSS) score at discharge and modified Rankin scale (mRS) score at 3 months.

RESULTS

Eleven patients (median NIHSS 12.8, mean age 61.6 years, male: female = 8:3) with acute IA occlusion were treated with TEB. All the patients presented with TICI 0, and the occluded vessel was the middle cerebral artery (n=7), the basilar artery (n=1), and the distal ICA occlusion (n = 3). IV infusion of tissue plasminogen activator (tPA) was done in 4 patients and mechanical thrombolysis with intra-arterial UK was performed in 9. Recanalization was achieved in 73% (8 patients; TICI ≥ 2). There were no procedure-related complications except for two asymptomatic intracranial hemorrhages. Improvement (≥ 4 points on the NIHSS) and good outcome (mRS ≤2) after 90 days was shown in six patients (55%). One patient died 6 days after procedure.

CONCLUSION

TEB may be a valuable treatment option in acute thromboembolic IA occlusion without stent implantation.

Optimizing prediction scores for poor outcome after intra-arterial therapy in anterior circulation acute ischemic stroke

BACKGROUND AND PURPOSE

Intra-arterial therapy (IAT) promotes recanalization of large artery occlusions in acute ischemic stroke. Despite high recanalization rates, poor clinical outcomes are common. We attempted to optimize a score that combines clinical and imaging variables to more accurately predict poor outcome after IAT in anterior circulation occlusions.

METHODS

Patients with acute ischemic stroke undergoing IAT at University of Texas (UT) Houston for large artery occlusions (middle cerebral artery or internal carotid artery) were reviewed. Independent predictors of poor outcome (modified Rankin Scale, 4-6) were studied. External validation was performed on IAT-treated patients at Emory University.

RESULTS

A total of 163 patients were identified at UT Houston. Independent predictors of poor outcome (P≤0.2) were identified as score variables using sensitivity analysis and logistic regression. Houston Intra-Arterial Therapy 2 (HIAT2) score ranges 0 to 10: age (≤59=0, 60-79=2, ≥80 years=4), glucose (<150=0, ≥150=1), National Institute Health Stroke Scale (≤10=0, 11-20=1, ≥21=2), the Alberta Stroke Program Early CT Score (8-10=0, ≤7=3). Patients with HIAT2≥5 were more likely to have poor outcomes at discharge (odds ratio, 6.43; 95% confidence interval, 2.75-15.02; P<0.001). After adjusting for reperfusion (Thrombolysis in Cerebral Infarction score≥2b) and time from symptom onset to recanalization, HIAT2≥5 remained an independent predictor of poor outcome (odds ratio, 5.88; 95% confidence interval, 1.96-17.64; P=0.02). Results from the cohort of Emory (198 patients) were consistent; patients with HIAT2 score≥5 had 6× greater odds of poor outcome at discharge and at 90 days. HIAT2 outperformed other previously published predictive scores.

CONCLUSIONS

The HIAT2 score, which combines clinical and imaging variables, performed better than all previous scores in predicting poor outcome after IAT for anterior circulation large artery occlusions.

Evidence-based changes in devices and methods of endovascular recanalization therapy

The devices and methods of endovascular recanalization therapy (ERT) have been rapidly developed and changed since PROACT II trial. Emerging as a treatment option in addition to intravenous or intra-arterial thrombolysis, mechanical thrombectomy is currently being further developed and investigated as a potential first-line and stand-alone treatment. This review highlights and summarizes the recent clinical series and trials of the available devices and methods of ERT focusing on the multimodal approach.

Comparison of stent-retriever devices versus the Merci retriever for endovascular treatment of acute stroke

BACKGROUND AND PURPOSE

Revascularization of large cerebral artery occlusion is the therapeutic goal in stroke therapy. Currently, many recanalization devices are in clinical use. This study compares the outcome parameters, efficacy, and safety of the new generation of stent-retriever devices with the well-established Merci retriever.

MATERIALS AND METHODS

All patients who received endovascular mechanical recanalization therapy were prospectively registered. One hundred twenty-two patients were treated with either new stent retrievers, including the Trevo and Solitaire devices, or the Merci retriever system. Recanalization of the occluded vessel was assessed in accordance with the modified TICI score, and outcome parameters, including the NIHSS and mRS scores, were documented. Clinical status was recorded after neurointervention, at time of discharge, and after 90 days.

RESULTS

The mean age of all patients was 68 years; 54% were male, with no statistical differences in demographics between both groups. Successful recanalization (TICI 3 and TICI 2b) was achieved in 82% of patients treated with stent retrievers compared with 62% of patients treated with Merci retrievers (P = .016). In the 90-day follow-up, 65% of patients treated with stent retrievers and 35% of those treated with the Merci had achieved a good (mRS = 0-2) clinical outcome (P = .002). Patients treated with stent retrievers had a significantly shorter treatment time (72 versus 122 minutes, P < .01) and less severe intracerebral hemorrhages (10% versus 28%, P < .01).

CONCLUSIONS

Patients treated with Trevo and Solitaire stents had a better revascularization rate, better clinical outcome, and lower complication rate than patients treated with the Merci retriever.

Improving patient selection for endovascular treatment of acute cerebral ischemia: a review of the literature and an external validation of the Houston IAT and THRIVE predictive scoring systems

Outcome after intraarterial therapy (IAT) for acute ischemic stroke remains variable, suggesting that improved patient selection is needed to better identify patients likely to benefit from treatment. The authors evaluate the predictive accuracies of the Houston IAT (HIAT) and the Totaled Health Risks in Vascular Events (THRIVE) scores in an independent cohort and review the existing literature detailing additional predictive factors to be used in patient selection for IAT. They reviewed their center's endovascular records from January 2004 to July 2010 and identified patients who had acute ischemic stroke and underwent IAT. They calculated individual HIAT and THRIVE scores using patient age, admission National Institutes of Health Stroke Scale (NIHSS) score, admission glucose level, and medical history. The scores' predictive accuracies for good outcome (discharge modified Rankin Scale score ≤ 3) were analyzed using receiver operating characteristics analysis. The THRIVE score predicts poor outcome after IAT with reasonable accuracy and may perform better than the HIAT score. Nevertheless, both measures may have significant clinical utility; further validation in larger cohorts that accounts for differences in patient demographic characteristics, variation in time-to-treatment, and center preferences with respect to IAT modalities is needed. Additional patient predictive factors have been reported but not yet incorporated into predictive scales; the authors suggest the need for additional data analysis to determine the independent predictive value of patient admission NIHSS score, age, admission hyperglycemia, patient comorbidities, thrombus burden, collateral flow, time to treatment, and baseline neuroimaging findings.

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

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

Intra-arterial thrombolysis using double devices: mechanicomechanical or chemicomechanical techniques

Objective

To optimize the recanalization of acute cerebral stroke that were not effectively resolved by conventional intraarterial thrombolysis (IAT), we designed a double device technique to allow for rapid and effective reopening. In this article, we describe the feasibility and efficacy of this technique.

Methods

From January 2008 to September 2009, twenty patients with acute cerebral arterial occlusion (middle cerebral artery : n=12; internal carotid artery terminus : n=5; basilar artery : n=3) were treated by the double device technique. This technique was applied when conventional thrombolytic methods using drug, microwires, microcatheters and balloons did not result in recanalization. In the double device technique, two devices are simultaneously placed at the lesion (for example, one microcatheter and one balloon or two microcatheters). Chemicomechanical or mechanicomechanical thrombolysis was performed simultaneously using various combinations of two devices. Recanalization rates, procedural time, complications, and clinical outcomes were analyzed.

Results

The initial median National Institute of Health Stroke Scale (NIHSS) was 16 (range 5-26). The double device technique was applied after conventional IAT methods failed. Recanalization was achieved in 18 patients (90%). Among them, 55% (11 cases) were complete (thrombolysis in cerebral infarction 2B, 3). The median thrombolytic procedural time including the conventional technique was 135±83.7 minutes (range 75-427). Major symptomatic hemorrhages (neurological deterioration ≥4 points in NIHSS) developed in two patients (10%). Good long term outcomes (modified Rankin Scale ≤2 at 90 days) occurred in 25% (n=5) of the cases. Mortality within 90 days developed in two cases (10%).

Conclusion

The double device technique is a feasible and effective technical option for large vessel occlusion refractory to conventional thrombolysis.

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.

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.

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.

Early single center experience with the solitaire thrombectomy device for the treatment of acute ischemic stroke

We report the immediate technical and clinical outcome of a new self-expanding fully retrievable stent in the treatment of acute ischemic stroke. Eleven consecutive patients with acute intracerebral artery occlusions were treated with a self-expandable fully retrievable intracranial stent (Solitaire AB). Four patients had an occlusion of the basilar artery, five had a middle cerebral artery occlusion and two had terminal carotid artery occlusions. Recanalization results were assessed by follow-up angiography immediately after the procedure. Neurologic status was evaluated before and after treatment (90-day follow-up) according to the National Institutes of Health Stroke Scale (NIHSS) and modified Rankin scales (mRS).Successful revascularization (TICI 2a/b and 3) was achieved in 11 of 11 (100%) patients, a TICI 3 state was accomplished in two (18%) patients, and partial recanalization or slow distal branch filling with filling of more than two-thirds of the vessel territory (TICI 2a/2b) was achieved in nine (82%) patients. The stent was removed in all patients. The mean time from stroke symptom onset to recanalization was 339 minutes (+/- 114.3 minutes). NIHSS on admission was 16.09 (+/- 4.7). Almost two-thirds of the patients (61.2%) improved by >6 points on the NIHSS at discharge, and 30% showed a mRS of <2 at 90 days. Mortality was 9%. One patient with a BA occlusion had a massive brain stem infarction and died two days after the procedure. There were no intracranial hemorrhages.The use of the Solitaire in ischemic stroke patients shows encouraging results. However, further prospective large randomized trials are mandatory to confirm these early results.

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.

Thrombolysis as a factor associated with favorable outcomes in patients with unclear-onset stroke

BACKGROUND AND PURPOSE

Clinical and radiological features of patients with unclear-onset stroke do not differ significantly from those with known-onset stroke. There is a lack of evidence for the safety and efficacy of thrombolysis in patients with unclear-onset stroke. We sought to provide supportive data on the safety and efficiency of thrombolysis in patients with unclear-onset stroke.

METHODS

We retrospectively identified patients with unclear-onset stroke (<3 h of first found abnormal time) from our stroke registry. We performed following protocols for thrombolysis in patients with unclear-onset stroke; initial conventional CT-based intravenous thrombolysis (IVT), repeat MRI during IVT, and then decision to maintain IVT or to perform combined intra-arterial thrombolysis. In addition, we compared clinical outcomes and safety between thrombolyzed and non-thrombolyzed patients.

RESULTS

A total of 78 patients with unclear-onset stroke were included. Twenty-nine patients underwent thrombolysis. Thrombolysis (OR, 6.842; 95% CI, 1.950-24.004; P = 0.003) and baseline NIHSS (OR, 0.769; 95% CI, 0.645-0.917; P = 0.003) were associated with favorable outcomes at 3 months in multivariate logistic regression analysis. The frequency of hemorrhagic transformation and symptomatic ICH was not significantly different between the thrombolyzed and non-thrombolyzed patients (34.4% vs. 40.7% and 10.3% vs. 8.2%, respectively).

CONCLUSION

The results of this study suggest that thrombolysis in unclear-onset stroke could be independently associated with favorable outcomes at 3 months and that thrombolysis based on repeat imaging appears to be safely applied to patients with unclear-onset stroke.

Stent-assisted mechanical recanalization for treatment of acute intracerebral artery occlusions

BACKGROUND AND PURPOSE

The purpose of this study was to demonstrate a new approach to the use of a self-expanding stent in the treatment of acute ischemic stroke.

METHODS

Twenty-two consecutive patients with acute intracerebral artery occlusions were treated with a self-expandable intracranial stent, which was withdrawn in its unfolded state. For this technique, we used the Solitaire AB/FR, which is the only intracranial stent that is fully recoverable. Eight patients had an occlusion of the basilar artery, 12 had a middle cerebral artery occlusion, and 2 had terminal carotid artery occlusions; 6 of these had to be treated first for an acute occlusion originating in the internal carotid artery. Recanalization results were assessed by follow-up angiography immediately after the procedure. Neurologic status was evaluated before and after treatment (90-day follow-up) according to the National Institutes of Health Stroke Scale and modified Rankin scale.

RESULTS

Successful revascularization was achieved in 20 of 22 (90.9%) patients (thrombolysis in cerebral infarction [TICI] 2a/b and 3), a TICI 3 state was accomplished in 12 patients, and partial recanalization or slow distal branch filling with filling of more than two-thirds of the vessel territory was achieved in 8 patients (TICI 2b). There was immediate flow restoration in 21 of 22 (95.4%) cases after deployment of the device. The stent was removed in its unfolded state in all patients. The mean time from stroke symptom onset to recanalization was 277 minutes, with a standard deviation of 118 minutes. Mean National Institutes of Health Stroke Scale score on admission was 19.4, with a standard deviation of 5.7. Almost two-thirds of the patients (63.6%) improved by > 10 points on the National Institutes of Health Stroke Scale at discharge, and 50% showed a modified Rankin scale score of ≤ 2 at 90 days (59% with a modified Rankin scale ≤ 3). Mortality was 18.1%. In 1 case, an asymptomatic intracranial hemorrhage was detected on control computed tomography, and 2 patients had a symptomatic intracranial hemorrhage.

CONCLUSIONS

Withdrawal of an unfolded, fully recoverable, intracranial stent yielded very promising angiographic and clinical results. It combines the advantages of prompt flow restoration and mechanical thrombectomy.

The effect of transcatheter injections on cell viability and cytokine release of mononuclear cells

BACKGROUND AND PURPOSE

Several studies suggest that various types of cellular therapies enhance recovery after stroke in animal models. IA-based delivery of cells to the brain is under investigation for stroke, but it is unknown whether cells are injured as a result of being injected through a catheter or exposed to iodinated contrast medium or solutions containing heparin.

MATERIALS AND METHODS

We assessed the effect of catheterization with the Excelsior SL-10 catheter or exposure to heparin or iodine contrast on human bone marrow MNCs. Viability and cell injury were assessed by trypan blue exclusion, caspase-3 activity, and lipid peroxidation. Cellular function of MNCs was assessed by their production and release of VEGF, IL-10, and IGF-1.

RESULTS

Flow rates of 10 million cells from 0.5 to 2 mL/min did not alter MNC viability; however, 5 mL/min of MNCs did reduce viability by 19%. Iodine and low-dose heparin exposure did not affect cell viability; however, high-dose heparin was cytotoxic. Catheter delivery at 2 mL/min did not affect levels of VEGF, IL-10, or IGF-1.

CONCLUSIONS

MNCs do not appear to be damaged by heparin, iodine contrast, and the Excelsior SL-10 catheter at flow rates up to 2 mL/min. However, higher flow rates did reduce viability, and high-dose heparin did cause cell death.

Current recommendations for endovascular interventions in the treatment of ischemic stroke

Ischemic stroke remains one of the leading cause of adult death and disability in the United States. Reperfusion of the occluded vessel is the standard of care in the setting of acute ischemic stroke according to established guidelines. Since the introduction of intravenous (IV) recombinant tissue plasminogen activator (rt-PA) in the late 1990s, significant advances have been made in methods to deliver thrombolytic agents and in devices for mechanical recanalization of occluded vessels. Furthermore, improvements in patient selection contribute to achievement of good clinical outcomes after endovascular therapy. This article summarizes findings from recent clinical trials and presents evidence-based guidelines for endovascular interventions in the treatment of ischemic stroke.