Recommendations on angiographic revascularization grading standards for acute ischemic stroke: a consensus statement

Special Endovascular Treatment for Acute Large Artery Occlusion Resulting From Atherosclerotic Disease

BACKGROUND

Acute intracranial atherosclerotic disease (IAD)-related large artery occlusion (LAO) is typically refractory to mechanical thrombectomy. We evaluated the feasibility and safety of emergency balloon-assisted or stent-assisted angioplasty performed with tirofiban administration for acute IAD-related LAO.

METHODS

We identified, from among 55 consecutive patients who underwent endovascular treatment for LAO, 12 patients with acute IAD-related LAO who underwent balloon-assisted or stent-assisted angioplasty with (n = 3) or without passage of a stent retriever. The treatment included tirofiban administration. We obtained, from patients' clinical records, thrombolysis in cerebral infarction scores (to assess the extent of reperfusion), follow-up magnetic resonance angiography images (to assess patency of the responsive arteries), and 90-day modified Rankin (mRS) scores (to assess outcomes).

RESULTS

Temporary blood flow and severe stenosis were observed angiographically in all 12 patients, either when the stent retriever was deployed or when a microcatheter was advanced through the site of occlusion. Persistent recanalization was achieved in all patients, and there was no operative complication or arterial reocclusion. All 8 patients with an occluded major artery in the anterior circulation had a good outcome, with an mRS score of ≤2. Two of the 4 patients with basilar artery occlusion had a good outcome, with an mRS score of ≤2. One patient (25%) died within 72 hours after procedure.

CONCLUSIONS

Our data point to the safety and feasibility of emergency balloon-assisted or stent-assisted angioplasty performed with tirofiban administration and a single or no passage of the stent retriever for acute IAD-related LAO.

Transradial approach for mechanical thrombectomy in anterior circulation large-vessel occlusion

OBJECTIVE

The goals of this study were to describe the authors' recent institutional experience with the transradial approach to anterior circulation large-vessel occlusions (LVOs) in acute ischemic stroke patients and to report its technical feasibility.

METHODS

The authors reviewed their institutional database to identify patients who underwent mechanical thrombectomy via a transradial approach over the 2 previous years, encompassing their experience using modern techniques including stent retrievers.

RESULTS

Eleven patients were identified. In 8 (72%) of these patients the right radial artery was chosen as the primary access site. In the remaining patients, transfemoral access was initially attempted. Revascularization (modified Treatment in Cerebral Ischemia [mTICI] score ≥ 2b) was achieved in 10 (91%) of 11 cases. The average time to first pass with the stent retriever was 64 minutes. No access-related complications occurred.

CONCLUSIONS

Transradial access for mechanical thrombectomy in anterior circulation LVOs is safe and feasible. Further comparative studies are needed to determine criteria for selecting the transradial approach in this setting.

Endovascular stroke treatment in a small-volume stroke center

INTRODUCTION

Our purpose was to evaluate the safety and efficacy of endovascular treatment (EVT) of stroke caused by large vessel occlusions (LVO) performed by general interventional radiologists in cooperation with stroke neurologists and neuroradiologists at a center with a limited annual number of procedures. We aimed to compare our results with those previously reported from larger stroke centers.

PATIENTS AND METHODS

A total of 108 patients with acute stroke due to LVO treated with EVT were included. Outcome was measured using the modified Rankin scale (mRS) at 90 days. Efficacy was classified according to the modified thrombolysis in cerebral infarction (mTICI) scoring system. Safety was evaluated according to the incidence of procedural complications and symptomatic intracranial hemorrhage (sICH).

RESULTS

Mean age of the patients was 67.5 years. The median National Institutes of Health Stroke Scale (NIHSS) on hospital admission was 17. Successful revascularization was achieved in 76%. 39.4% experienced a good clinical outcome (mRS<3). Intraprocedural complications were seen in 7.4%. 7.4% suffered a sICH. 21.3% died within 3 months after EVT.

DISCUSSION

The use of general interventional radiologists in EVT of LVO may be a possible approach for improving EVT coverage where availability of specialized neurointerventionalists is challenging. EVT for LVO stroke performed by general interventional radiologists in close cooperation with diagnostic neuroradiologists and stroke neurologists can be safe and efficacious despite the low number of annual procedures.

ERic Acute StrokE Recanalization: A study using predictive analytics to assess a new device for mechanical thrombectomy

Aim and hypothesis Using a new study design, we investigate whether next-generation mechanical thrombectomy devices improve clinical outcomes in ischemic stroke patients. We hypothesize that this new methodology is superior to intravenous tissue plasminogen activator therapy alone. Methods and design ERic Acute StrokE Recanalization is an investigator-initiated prospective single-arm, multicenter, controlled, open label study to compare the safety and effectiveness of a new recanalization device and distal access catheter in acute ischemic stroke patients with symptoms attributable to acute ischemic stroke and vessel occlusion of the internal cerebral artery or middle cerebral artery. Study outcome The primary effectiveness endpoint is the volume of saved tissue. Volume of saved tissue is defined as difference of the actual infarct volume and the brain volume that is predicted to develop infarction by using an optimized high-level machine learning model that is trained on data from a historical cohort treated with IV tissue plasminogen activator. Sample size estimates Based on own preliminary data, 45 patients fulfilling all inclusion criteria need to complete the study to show an efficacy >38% with a power of 80% and a one-sided alpha error risk of 0.05 (based on a one sample t-test). Discussion ERic Acute StrokE Recanalization is the first prospective study in interventional stroke therapy to use predictive analytics as primary and secondary endpoint. Such trial design cannot replace randomized controlled trials with clinical endpoints. However, ERic Acute StrokE Recanalization could serve as an exemplary trial design for evaluating nonpivotal neurovascular interventions.

Vessel Patency at 24 Hours and Its Relationship With Clinical Outcomes and Infarct Volume in REVASCAT Trial (Randomized Trial of Revascularization With Solitaire FR Device Versus Best Medical Therapy in the Treatment of Acute Stroke Due to Anterior Circulation Large Vessel Occlusion Presenting Within Eight Hours of Symptom Onset)

BACKGROUND AND PURPOSE

Higher rates of target vessel patency at 24 hours were noted in the thrombectomy group compared with control group in recent randomized trials. As a prespecified secondary end point, we aimed to assess 24-hour revascularization rates by treatment groups and occlusion site as they related to clinical outcome and 24-hour infarct volume in REVASCAT (Randomized Trial of Revascularization With Solitaire FR Device Versus Best Medical Therapy in the Treatment of Acute Stroke Due to Anterior Circulation Large Vessel Occlusion Presenting Within Eight Hours of Symptom Onset).

METHODS

Independent core laboratory adjudicated vessel status according to modified arterial occlusive lesion classification at 24 hours on computed tomographic/magnetic resonance (94.2%/5.8%) angiography and 24-hour infarct volume on computed tomography were studied (95/103 patients in the thrombectomy group versus 94/103 in the control group, respectively). Complete revascularization was defined as modified arterial occlusive lesion grade 3. Its effect on clinical outcome was analyzed by ordinal logistic regression.

RESULTS

Complete revascularization was achieved in 70.5% of the solitaire group and in 22.3% of the control group (P<0.001). Significant differences in complete revascularization rates were found for terminus internal carotid artery, M1, and tandem occlusions (all P<0.001) but not for M2 occlusions. In the thrombectomy group, 2 out of 63 patients (3.1%) with modified Thrombolysis in Cerebral Infarction 2b/3 after thrombectomy showed arterial reocclusion (modified arterial occlusive lesion grade 0/1) at 24 hours. Complete revascularization was associated with improved outcome in both thrombectomy (adjusted odds ratio, 4.5; 95% confidence interval, 1.9-10.9) and control groups (adjusted odds ratio, 2.7; 95% confidence interval, 1.0-6.7). Revascularization (modified arterial occlusive lesion grade 2/3) was associated with smaller infarct volumes in either treatment arm.

CONCLUSIONS

Complete revascularization at 24 hours is a powerful predictor of favorable clinical outcome, whereas revascularization of any type results in reduced infarct volume in both thrombectomy and control groups.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01692379.

Early computed tomography-based scores to predict decompressive hemicraniectomy after endovascular therapy in acute ischemic stroke

Background

Identification of patients requiring decompressive hemicraniectomy (DH) after endovascular therapy (EVT) is crucial as clinical signs are not reliable and early DH has been shown to improve clinical outcome. The aim of our study was to identify imaging-based scores to predict the risk for space occupying ischemic stroke and DH.

Methods

Prospectively derived data from patients with acute large artery occlusion within the anterior circulation and EVT was analyzed in this monocentric study. Predictive value of non-contrast cranial computed tomography (ncCT) and cerebral blood volume (CBV) Alberta Stroke Program Early CT score (ASPECTS) were investigated for DH using logistic regression models and Receiver Operating Characteristic Curve analysis.

Results

From 218 patients with EVT, DH was performed in 20 patients (9.2%). Baseline- (7 vs. 9; p = 0.009) and follow-up ncCT ASPECTS (1 vs. 7, p<0.001) as well as baseline CBV ASPECTS (5 vs. 7, p<0.001) were significantly lower in patients with DH. ncCT (baseline: OR 0.71, p = 0.018; follow-up: OR 0.32, p = <0.001) and CBV ASPECTS (OR 0.63, p = 0.008) predicted DH. Cut-off ncCT-ASPECTS on baseline was 7-, ncCT-ASPECTS on follow-up was 4- and CBV ASPECTS on baseline was 5 points.

Conclusions

ASPECTS could be useful to early identify patients requiring DH after EVT for acute large vessel occlusion.

Cervical Carotid Pseudo-Occlusions and False Dissections

Background and Purpose—

Pseudo-occlusion (PO) of the cervical internal carotid artery (ICA) refers to an isolated occlusion of the intracranial ICA that appears as an extracranial ICA occlusion on computed tomography angiography (CTA) or digital subtraction angiography because of blockage of distal contrast penetration by a stagnant column of unopacified blood. We aim to better characterize this poorly recognized entity.

Methods—

Retrospective review of an endovascular database (2010–2015; n=898). Only patients with isolated intracranial ICA occlusions as confirmed by angiographic exploration were included. CTA and digital subtraction angiography images were categorized according to their apparent site of occlusion as (1) extracranial ICA PO or (2) discernible intracranial ICA occlusion.

Results—

Cervical ICA PO occurred in 21/46 (46%) patients on CTA (17 proximal cervical; 4 midcervical). Fifteen (71%) of these patients also had PO on digital subtraction angiography. A flame-shaped PO mimicking a carotid dissection was seen in 7 (33%) patients on CTA and in 6 (29%) patients on digital subtraction angiography. Patients with and without CTA PO had similar age (64.8±17.1 versus 60.2±15.7 years; P =0.35), sex (male, 47% versus 52%; P =1.00), and intravenous tissue-type plasminogen activator use (38% versus 40%; P =1.00). The rates of modified Treatment In Cerebral Ischemia 2b-3 reperfusion were 71.4% in the PO versus 100% in the non-PO cohorts ( P <0.01). The rates of parenchymal hematoma, 90-day modified Rankin Scale score 0–2, and 90-day mortality were 4.8% versus 8% ( P =0.66), 40% versus 66.7% ( P =0.12), and 25% versus 21% ( P =0.77) in PO versus non-PO patients, respectively. Multivariate analysis indicated that PO patients had lower chances of modified Treatment In Cerebral Ischemia 3 reperfusion (odds ratio 0.14; 95% confidence interval 0.02–0.70; P =0.01).

Conclusions—

Cervical ICA PO is a relatively common entity and may be associated with decreased reperfusion rates.

Review of Post Ischemic Stroke Imaging and Its Clinical Relevance

In this day and age, multiple imaging modalities are available to the stroke physician in the post-treatment phase.The practical challenge for physicians who treat stroke is to evaluate the pros and cons of each technique and select the best choice for the situation. The choice of imaging modality remains contentious at best and varies among different institutions and centres. This is no simple task an there are many factors to consider, including the differential diagnosis which need to be evaluated, the availability and reliability of the imaging technique and time and expertise required to perform and interpret the scanning. Other ancillary competing interest also come into play such as the financial cost of the modality, the requirement for patient monitoring during the imaging procedure and patient comfort. In an effort to clear some of the ambiguity surrounding this topic we present some of the current techniques in use and others, which are still in the realm of research and have not yet transitioned into clinical practice.

The effects of pharmaceutical thrombolysis and multi-modal therapy on patients with acute posterior circulation ischemic stroke: Results of a one center retrospective study

BACKGROUND

The treatment method for acute ischemic stroke is rapidly developing, and the effects of endovascular modalities, when used alone or in combination, needs to be studied. We aimed to identify the difference between pharmaceutical thrombolysis and multi-modal therapy (MMT) used in acute posterior circulation ischemic stroke (APCIS) patients and also to detect the predictors for successful recanalization and favorable outcomes.

METHODS

A retrospective analysis of patients with APCIS who received thrombolytic pharmaceuticals and MMT from 2011 to 2016 was performed at the stroke center. Demographic information, therapeutic methods and the results were recorded. Logistic regression model was constructed in variables to determine the predictors of outcome.

RESULTS

A total of 124 patients were included in this study, the mean age was 59.6 ± 9.5 years and the mean admission National Institutes of Health Stroke Scale (NIHSS) was 15.1 ± 6.6. Recanalization was achieved in 87 (70.2%) patients and favorable outcomes were observed in 65 (52.4%) patients. Patients treated with MMT demonstrated a higher recanalization rate, especially the use of stent placement and thrombectomy device, which were also related to the favorable outcome three months post-stroke. Logistic regression showed that stent placement and thrombectomy were the predictors of recanalization, and a favorable outcome was associated with coronary artery disease, MMT methods as well as recanalization.

CONCLUSION

MMT methods, especially stent placement and thrombectomy device may be the first recommended for patients with a delayed admission time, and it may have the advantage of better perfusion and neurological outcomes.

Distinctive patterns on CT angiography characterize acute internal carotid artery occlusion subtypes

Noninvasive computed tomography angiography (CTA) is widely used in acute ischemic stroke, even for diagnosing various internal carotid artery (ICA) occlusion sites, which often need cerebral digital subtraction angiography (DSA) confirmation. We evaluated whether clinical outcomes vary depending on the DSA-based occlusion sites and explored correlating features on baseline CTA that predict DSA-based occlusion site.We analyzed consecutive patients with acute ICA occlusion who underwent DSA and CTA. Occlusion site was classified into cervical, cavernous, petrous, and carotid terminus segments by DSA confirmation. Clinical and radiological features associated with poor outcome at 3 months (3-6 of modified Rankin scale) were analyzed. Baseline CTA findings were categorized according to carotid occlusive shape (stump, spearhead, and streak), presence of cervical calcification, Willisian occlusive patterns (T-type, L-type, and I-type), and status of leptomeningeal collaterals (LMC).We identified 49 patients with occlusions in the cervical (n = 17), cavernous (n = 22), and carotid terminus (n = 10) portions: initial NIH Stroke Scale (11.4 ± 4.2 vs 16.1 ± 3.7 vs 18.2 ± 5.1; P < 0.001), stroke volume (27.9 ± 29.6 vs 127.4 ± 112.6 vs 260.3 ± 151.8 mL; P < 0.001), and poor outcome (23.5 vs 77.3 vs 90.0%; P < 0.001). Cervical portion occlusion was characterized as rounded stump (82.4%) with calcification (52.9%) and fair LMC (94.1%); cavernous as spearhead occlusion (68.2%) with fair LMC (86.3%) and no calcification (95.5%); and terminus as streak-like occlusive pattern (60.0%) with poor LMC (60.0%), and no calcification (100%) on CTA.Our study indicates that acute ICA occlusion can be subtyped into cervical, cavernous, and terminus. Distinctive findings on initial CTA can help differentiate ICA-occlusion subtypes with specific characteristics.

Predictive Factors for Good Outcome and Mortality After Stent-Retriever Thrombectomy in Patients With Acute Anterior Circulation Stroke

Background and Purpose

Predictive factors associated with stent-retriever thrombectomy for patients with acute anterior circulation stroke remain to be elucidated. This study aimed to investigate clinical and procedural factors predictive of good outcome and mortality after stent-retriever thrombectomy in a large cohort of patients with acute anterior circulation stroke.

Methods

We analyzed clinical and procedural data in 335 patients with acute anterior circulation stroke treated with stent-retriever thrombectomy. A good outcome was defined as a modified Rankin Scale score of 0 to 2 at 3 months. The associations between clinical, imaging, and procedural factors and good outcome and mortality, respectively, were evaluated using logistic regression analysis.

Results

Using multivariate analysis, age (odds ratio [OR], 0.965; 95% confidence interval [CI], 0.944-0.986; P=0.001), successful revascularization (OR, 4.658; 95% CI, 2.240-9.689; P<0.001), parenchymal hemorrhage (OR, 0.150; 95% CI, 0.049-0.460; P=0.001), and baseline NIHSS score (OR, 0.908; 95% CI, 0.855-0.965; P=0.002) were independent predictors of good outcome. Independent predictors of mortality were age (OR, 1.043; 95% CI, 1.002-1.086; P=0.041), successful revascularization (OR, 0.171; 95% CI, 0.079-0.370; P<0.001), parenchymal hemorrhage (OR, 2.961; 95% CI, 1.059-8.276; P=0.038), and a history of previous stroke/TIA (OR, 3.124; 95% CI, 1.340-7.281; P=0.008).

Conclusions

Age, revascularization status, and parenchymal hemorrhage are independent predictors of both good outcome and mortality after stent retriever thrombectomy for acute anterior circulation stroke. In addition, NIHSS score on admission is independently associated with good outcome, whereas a history of previous stroke is independently associated with mortality.

Elevated mean platelet volume is associated with poor outcome after mechanical thrombectomy

Background

Elevated mean platelet volume (MPV), indicating higher platelet activity, could be a predictor of prognosis in patients with acute ischemic stroke receiving medical therapy.

Objective

To investigate the relationship between MPV and functional outcome in patients with acute anterior circulation stroke 3 months after undergoing mechanical thrombectomy (MT).

Methods

A total of 153 consecutive patients with acute stroke following MT, in two separate stroke centers, were enrolled between May 2013 and March 2016. MPV was measured on admission. Subjects were divided into two groups according to average MPV level. Univariate and multivariate analyses were performed. MPV was also incorporated into the Houston IA Therapy (HIAT) score, which was developed as a scoring system to predict poor prognosis, and the prediction capability was compared with the HIAT score alone.

Results

The average MPV was 10.4 fL. Patients with high MPV had a significantly lower rate of functional independence (28.9% vs 57.1%, p=0.000). After multivariable analysis, elevated MPV remained an independent predictor of unfavorable outcome (OR=3.93, 95% CI 1.73 to 8.94, p=0.001). When the MPV cut-off value was set at 10.4 fL using the receiver operating characteristic (ROC) analysis, MPV ≥10.4 fL predicted unfavorable outcome with 62.1% sensitivity and 66.7% specificity, respectively. Addition of MPV to the HIAT score did not improve predictive power compared with the HIAT score system alone by a comparison of the areas under the two ROC curves (0.70 vs 0.62, p=0.174).

Conclusions

Elevated MPV is an independent predictor of poor outcome in patients with acute anterior circulation stroke undergoing MT at 3 months.

Correlation of Acute M1 Middle Cerebral Artery Thrombus Location with Endovascular Treatment Success and Clinical Outcome

PURPOSE

The location of the arterial occlusion can help with prognostication and treatment triage of acute stroke patients. We aimed to determine the effects of M1 distance-to-thrombus on angiographic recanalization success rate and clinical outcome following endovascular treatment of acute M1 occlusion.

METHODS

All acute ischemic stroke patients with M1 segment middle cerebral artery (MCA) occlusion on admission CT angiography (CTA) who underwent endovascular treatment were analyzed. The distance between thrombus origin and internal carotid artery (ICA) bifurcation was measured on admission CTA. The modified thrombolysis in cerebral infarction (mTICI) grades 2b (>50% of distal branch filling) and 3 (complete) were considered as successful recanalization. Favorable outcome was defined by 3-month follow-up modified Rankin scale (mRs) score ≤2.

RESULTS

Successful recanalization was achieved in 24 (71%) of 34 consecutive patients included in this study. The M1 distance-to-thrombus was shorter among patients with successful recanalization (5.4 ± 5.4 mm) versus those without (11.3 ± 7.6 mm, p = 0.015). The successful recanalization rate was higher among patients with M1 distance-to-thrombus ≤6 mm (odds ratio: 8, 95% confidence interval: 1.37-46.81, p = 0.023) compared with those with distance-to-thrombus >6 mm. There was no significant correlation between M1 distance-to-thrombus and 3-month mRs (rho: 0.131, p = 0.461); however, the distance-to-thrombus negatively correlated with admission National Institutes of Health Stroke Scale (NIHSS) scores (rho: -0.350, p=0.043). On the other hand, successful recanalization and admission NIHSS score were the only independent predictors of favorable outcome.

CONCLUSION

Shorter distance of M1 thrombus from ICA bifurcation is associated with higher rate of successful recanalization following endovascular treatment.

Effects of Workflow Optimization in Endovascularly Treated Stroke Patients - A Pre-Post Effectiveness Study

Endovascular treatment of acute ischemic stroke has become standard of care for patients with large artery occlusion. Early restoration of blood flow is crucial for a good clinical outcome. We introduced an interdisciplinary standard operating procedure (SOP) between neuroradiologists, neurologists and anesthesiologists in order to streamline patient management. This study analyzes the effect of optimized workflow on periprocedural timings and its potential influence on clinical outcome. Data were extracted from a prospectively maintained university hospital stroke database. The standard operating procedure was established in February 2014. Of the 368 acute stroke patients undergoing endovascular treatment between 2008 and 2015, 278 patients were treated prior to and 90 after process optimization. Outcome measures were periprocedural time intervals and residual functional impairment. After implementation of the SOP, time from symptom onset to reperfusion was significantly reduced (median 264 min prior and 211 min after SOP-introduction (IQR 228–32 min and 161–278 min, respectively); P<0.001). Especially faster supply of imaging and prompt transfer of patients to the angiography suite contributed to this effect. Time between hospital admission and groin puncture was reduced by half after process optimization (median 64 min after versus 121 min prior to SOP-introduction (IQR 54–77 min and 96–161 min, respectively); P<0.001). Clinical outcome was significantly better after workflow optimization as measured with the modified Rankin Scale (common odds ratio (OR) 0.56; 95% CI 0.32–0.98; P = 0.038). Optimization of workflow and interdisciplinary teamwork significantly improved the outcome of patients with acute ischemic stroke due to a significant reduction of in-hospital examination, transportation, imaging and treatment times.

Mechanical thrombectomy for basilar artery thrombosis: a comparison of outcomes with anterior circulation occlusions

Background and purpose

The benefits of mechanical thrombectomy (MT) in basilar artery occlusions (BAO) have not been explored in recent clinical trials. We compared outcomes and procedural complications of MT in BAO with anterior circulation occlusions.

Methods

Data from the Madrid Stroke Network multicenter prospective registry were analyzed, including baseline characteristics, procedure times, procedural complications, symptomatic intracranial hemorrhage (SICH), modified Rankin Scale (mRS), and mortality at 3 months.

Results

Of 479 patients treated with MT, 52 (11%) had BAO. The onset to reperfusion time lapse was longer in patients with BAO (median (IQR) 385 min (320–540) vs 315 min (240–415), p<0.001), as was the duration of the procedures (100 min (40–130) vs 60 min (39–90), p=0.006). Moreover, the recanalization rate was lower (75% vs 84%, p=0.01). A trend toward more procedural complications was observed in patients with BAO (32% vs 21%, p=0.075). The frequency of SICH was 2% vs 5% (p=0.25). At 3 months, patients with BAO had a lower rate of independence (mRS 0–2) (40% vs 58%, p=0.016) and higher mortality (33% vs 12%, p<0.001). The rate of futile recanalization was 50% in BAO versus 35% in anterior circulation occlusions (p=0.05). Age and duration of the procedure were significant predictors of futile recanalization in BAO.

Conclusions

MT is more laborious and shows more procedural complications in BAO than in anterior circulation strokes. The likelihood of futile recanalization is higher in BAO and is associated with greater age and longer procedure duration. A refinement of endovascular procedures for BAO might help optimize the results.

Catch Plus thrombectomy device in acute stroke: initial evaluation

OBJECTIVE

To report our initial experience with the Catch Plus thrombectomy device (CPD) in patients with acute ischemic stroke (AIS).

MATERIALS AND METHODS

We retrospectively evaluated the procedural variables as well as the clinical and angiographic outcomes of patients with acute occlusion of a major intracranial artery in the anterior circulation who were treated with CPD at our center. Baseline characteristics (gender, age, comorbidities, cardiovascular risk factors, National Institutes of Health Stroke Scale (NIHSS) score, and vessel occlusion sites) of these patients were recorded. Thrombolysis in Cerebral Infarction (TICI) score, incidence of symptomatic and asymptomatic bleeding, and 90 day modified Rankin Scale (mRS) scores were evaluated as indicators of outcome.

RESULTS

38 patients with a mean age of 67.5 years were treated with CPD. Mean time from symptom onset to procedure initiation was 226.7 min. Recanalization (TICI 2b-3) was achieved in 27 patients (71.1%). The median NIHSS score on admission was 20. Rates of symptomatic and asymptomatic intracerebral hemorrhage were 7.9% and 13.2%, respectively. The 90 day clinical follow-up data were available for 37 patients. The 90 day mortality rate was 18.9%, and the 90 day clinically acceptable functional outcome (mRS score ≤2) rate was 43.2% (mRS score 0-3, 54.1%). Very distal thrombectomy involving the cortical arteries was performed on four patients without complications.

CONCLUSIONS

Our initial experience suggests that mechanical thrombectomy with the CPD improves 90 day outcomes of patients with AIS by facilitating effective recanalization.

Endovascular Management vs Intravenous Thrombolysis for Acute Stroke Secondary to Carotid Artery Dissection: Local Experience and Systematic Review

BACKGROUND

Little is known regarding the endovascular management of acute ischemic stroke (AIS) related to carotid artery dissection (CAD).

OBJECTIVE

To report our interventional experience in AIS from CAD and to compare it with conservative treatment of CAD with intravenous thrombolysis (IVT) via systematic review.

METHODS

Retrospective analysis of consecutive high-grade steno-occlusive CAD with National Institutes of Health Stroke Scale (NIHSS) >5 and ≤12 hours of last seen normal from 2 tertiary centers. A systematic review for studies on IVT in the setting of CAD via PubMed was performed for comparison.

RESULTS

Of 1112 patients treated with endovascular interventions within the study period, 21 met the inclusion criteria. Mean age was 52.0 ± 10.9 years, 76% were male, NIHSS was 17.4 ± 5.8, 52% received IVT before intervention, and 90% had tandem occlusions. Mean time from last-known-normal to puncture was 4.8 ± 2.1 hours and procedure length 1.8 ± 1.0 hours. Stents were used in 52% of cases, and reperfusion (modified Treatment in Cerebral Ischemia 2b-3) achieved in 95%. No parenchymal hemorrhages were observed and 71% achieved good outcome (90-day modified Rankin Scale 0-2). The literature review identified 8 studies concerning thrombolysis in the CAD setting fitting inclusion criteria (n = 133). Our endovascular experience compared with the pooled IVT reports indicated that, despite presenting with higher NIHSS (17 vs 14; P = .04) and experiencing a longer time to definitive therapy (287 vs 162 minutes; P < .01), patients treated intra-arterially had similar rates of symptomatic cerebral/European Cooperative Acute Stroke Study-parenchymal hematoma 2 hemorrhage (0% vs 6%; P = .43) and good outcomes (71% vs 52%; P = .05).

CONCLUSION

Our study provides evidence that the endovascular management of AIS in the setting of CAD is a feasible, safe, and promising strategy.

Acute endovascular treatment delivery to ischemic stroke patients transferred within a telestroke network: a retrospective observational study

Background Five randomized controlled trials recently demonstrated efficacy of endovascular treatment in acute ischemic stroke. Telestroke networks can improve stroke care in rural areas but their role in patients undergoing endovascular treatment is unknown. Aim We compared clinical outcomes of endovascular treatment between anterior circulation stroke patients transferred after teleconsultation and those directly admitted to a tertiary stroke center. Methods Data derived from consecutive patients with intracranial large vessel occlusion who underwent endovascular treatment from January 2010 to December 2014 at our tertiary stroke center. We compared baseline characteristics, onset-to-treatment times, symptomatic intracranial hemorrhage, in-hospital mortality, reperfusion (modified Treatment in Cerebral Infarction 2b/3), and favorable functional outcome (modified Rankin scale ≤ 2) at discharge between patients transferred from spoke hospitals and those directly admitted. Results We studied 151 patients who underwent emergent endovascular treatment for anterior circulation stroke: median age 70 years (interquartile range, 62-75); 55% men; median National Institutes of Health Stroke Scale score 15 (12-20). Of these, 48 (31.8%) patients were transferred after teleconsultation and 103 (68.2%) were primarily admitted to our emergency department. Transferred patients were younger (p = 0.020), received more frequently intravenous tissue plasminogen activator (p = 0.008), had prolonged time from stroke onset to endovascular treatment initiation (p < 0.0001) and tended to have lower rates of symptomatic intracranial hemorrhage (4.2% vs. 11.7%; p = 0.227) and mortality (8.3% vs. 22.6%; p = 0.041) than directly admitted patients. Similar rates of reperfusion (56.2% vs. 61.2%; p = 0.567) and favorable functional outcome (18.8% vs. 13.7%; p = 0.470) were observed in telestroke patients and those who were directly admitted. Conclusions Telestroke networks may enable delivery of endovascular treatment to selected ischemic stroke patients transferred from remote hospitals that is equitable to patients admitted directly to tertiary hospitals.

Does prior antiplatelet treatment improve functional outcome after intra-arterial treatment for acute ischemic stroke?

Background and purpose

In patients with acute ischemic stroke who receive antiplatelet treatment, uncertainty exists about the effect and safety of intra-arterial treatment. Our aim was to study whether intra-arterial treatment in patients with prior antiplatelet treatment is safe and whether prior antiplatelet treatment modifies treatment effect.

Methods

All 500 MR CLEAN patients were included. We estimated the effect of intra-arterial treatment with ordinal logistic regression analysis, and tested for interaction of antiplatelet treatment with intra-arterial treatment on outcome. Furthermore, safety parameters and serious adverse events were analyzed.

Results

The 144 patients (29%) on antiplatelet treatment were older, more often male, and had more vascular comorbidity. Intra-arterial treatment effect size after adjustments in antiplatelet treatment patients was 1.7 (95% confidence interval 0.9–3.2), and in no antiplatelet treatment patients 1.8 (95% confidence interval: 1.2–2.6). There was no statistically or clinically significant interaction between prior antiplatelet treatment and the relative effect of intra-arterial treatment ( p = 0.78). However, in patients on antiplatelet treatment, the effect of successful reperfusion on functional outcome in the intervention arm of the trial was doubled: the absolute risk difference for favorable outcome after successful reperfusion in patients on prior antiplatelet treatment was 39% versus 18% in patients not on prior antiplatelet treatment (Pinteraction = 0.025). Patients on antiplatelet treatment more frequently had a symptomatic intracranial hemorrhage (15%) compared to patients without antiplatelet treatment (4%), without differences between the control and intervention arm.

Conclusions

Prior treatment with antiplatelet agents did not modify the effect of intra-arterial treatment in patients with acute ischemic stroke presenting with an intracranial large vessel occlusion. There were no safety concerns. In patients with reperfusion, antiplatelet agents may improve functional outcome.

Impact of Modified TICI 3 versus Modified TICI 2b Reperfusion Score to Predict Good Outcome following Endovascular Therapy

BACKGROUND AND PURPOSE

The TICI score is widely used to evaluate cerebral perfusion before and after the endovascular treatment of stroke. Recent studies showing the effectiveness and safety of mechanical thrombectomy combine modified TICI 2b and modified TICI 3 to assess the technical success of endovascular treatment. The purpose of this study was to determine how much clinical outcomes differ between patients achieving modified TICI 2b and modified TICI 3 reperfusion.

MATERIALS AND METHODS

We analyzed 222 consecutive patients with acute large intracranial artery occlusion of the anterior circulation having achieved modified TICI 2b or modified TICI 3 reperfusion after thrombectomy. The primary end point was the rate of favorable outcome defined as the achievement of a modified Rankin Scale score of 0-2 at 3 months.

RESULTS

Patients with modified TICI 3 more often had favorable collateral circulation and atherosclerosis etiology, with a shorter time from onset to reperfusion than patients with modified TICI 2b (all P < .05). The number of total passes to achieve reperfusion was higher in the modified TICI 2b group (median, 2; interquartile range, 1-3, 1-9) versus (median, 1; interquartile range, 1-2, 1-8) in the modified TICI 3 group (P = .0002). Favorable outcome was reached more often for patients with modified TICI 3 than for those with modified TICI 2b (71.7% versus 50.5%, P = .001), with a similar difference when considering excellent outcome. In addition, patients with modified TICI 3 had a lower intracerebral hemorrhage rate (23.0% versus 45.0%, P < .001).

CONCLUSIONS

Patients with modified TICI 3 reperfusion have better functional outcomes than those with modified TICI 2b. Given the improving reperfusion rates obtained with thrombectomy devices, future thrombectomy trials should consider modified TICI 2b and modified TICI 3 status separately.

Even Small Decreases in Blood Pressure during Conscious Sedation Affect Clinical Outcome after Stroke Thrombectomy: An Analysis of Hemodynamic Thresholds

BACKGROUND AND PURPOSE

The adverse effects of general anesthesia in stroke thrombectomy have been attributed to intraprocedural hypotension, yet optimal hemodynamic targets remain elusive. Identifying hemodynamic thresholds from patients without exposure to general anesthesia may help separate the effect of hypotension from the effect of anesthesia in thrombectomy outcomes. Therefore, we investigated which hemodynamic parameters and targets best correlate with outcome in patients treated under sedation with monitored anesthesia care.

MATERIALS AND METHODS

We performed a retrospective analysis of a prospectively collected data base of patients with anterior circulation stroke who were successfully reperfused (modified TICI ≥ 2b) under monitored anesthesia care sedation from 2010 to 2015. Receiver operating characteristic curves were generated for the lowest mean arterial pressure before reperfusion, both as absolute values and relative changes from baseline. Cutoffs were tested in binary logistic regression models of poor outcome (90-day mRS > 2).

RESULTS

Two-hundred fifty-six of 714 patients met the inclusion criteria. In a multivariable model, a ≥10% mean arterial pressure decrease from baseline had an OR for poor outcome of 4.38 (95% CI, 1.53-12.56; P < .01). Other models revealed that any mean pressure of <85 mm Hg before reperfusion had an OR for poor outcome of 2.22 (95% CI, 1.09-4.55; P = .03) and that every 10-mm Hg drop in mean arterial pressure below 100 mm Hg had an OR of 1.28 (95% CI, 1.01-1.62; P = .04).

CONCLUSIONS

A ≥10% mean arterial pressure drop from baseline is a strong risk factor for poor outcome in a homogeneous population of patients with stroke undergoing thrombectomy under sedation. This threshold could guide hemodynamic management of patients during sedation and general anesthesia.

Selecting Patients for Intra-Arterial Therapy in the Context of a Clinical Trial for Neuroprotection

BACKGROUND AND PURPOSE

The advent of intra-arterial neurothrombectomy (IAT) for acute ischemic stroke opens a potentially transformative opportunity to improve neuroprotection studies. Combining a putative neuroprotectant with recanalization could produce more powerful trials but could introduce heterogeneity and adverse event possibilities. We sought to demonstrate feasibility of IAT in neuroprotectant trials by defining IAT selection criteria for an ongoing neuroprotectant clinical trial.

METHODS

The study drug, 3K3A-APC, is a pleiotropic cytoprotectant and may reduce thrombolysis-associated hemorrhage. The NeuroNEXT trial NN104 (RHAPSODY) is designed to establish a maximally tolerated dose of 3K3A-APC. Each trial site provided their IAT selection criteria. An expert panel reviewed site criteria and published evidence. Finally, the trial leadership designed IAT selection criteria.

RESULTS

Derived selection criteria reflected consistency among the sites and comparability to published IAT trials. A protocol amendment allowing IAT (and relaxed age, National Institutes of Health Stroke Scale, and time limits) in the RHAPSODY trial was implemented on June 15, 2015. Recruitment before and after the amendment improved from 8 enrolled patients (601 screened, 1.3%) to 51 patients (821 screened, 6.2%; odds ratio [95% confidence limit] of 4.9 [2.3-10.4]; P<0.001). Gross recruitment was 0.11 patients per site month versus 0.43 patients per site per month, respectively, before and after the amendment.

CONCLUSIONS

It is feasible to include IAT in a neuroprotectant trial for acute ischemic stroke. Criteria are presented for including such patients in a manner that is consistent with published evidence for IAT while still preserving the ability to test the role of the putative neuroprotectant.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT02222714.

Impact of the Penumbral Pattern on Clinical Outcome in Patients with Successful Endovascular Revascularization

BACKGROUND

In patients with acute ischemic stroke, the impact of penumbral patterns on clinical outcomes after endovascular treatment (EVT) remains controversial. We aimed to establish whether penumbral patterns are associated with clinical outcome after successful recanalization with EVT while adjusting for onset to revascularization time.

MATERIALS AND METHODS

Using a web-based, multicenter, prospective stroke registry database, we identified patients with acute ischemic stroke who underwent perfusion and diffusion magnetic resonance imaging (MRI) before EVT, had anterior circulation stroke, received EVT within 12 hours of symptom onset, and had successful revascularization confirmed during EVT. Based on pretreatment MRI, patients were stratified as having a favorable or nonfavorable penumbral pattern. Onset to revascularization time was dichotomized by median value. Primary outcome was functional independence (modified Rankin Scale score ≤2) at 90 days.

FINDINGS

Among 121 eligible patients from three university hospitals, 104 (86.0%) had a favorable penumbral pattern, and the median time to revascularization was 271 minutes (interquartile range, 196-371). The functionally independent patient proportion was higher in those with a favorable penumbral pattern than in those without (53.8% versus 5.9%; P <.001), but was not different between early and late revascularization groups (49.2% versus 45.0%; P = .65). The favorable penumbral pattern was associated with functional independence after adjusting confounders (odds ratio, 23.25; 95% confidence interval: 1.58-341.99; P = .02). Time to revascularization did not modify the association (P for interaction, .53).

CONCLUSION

A favorable penumbral pattern is associated with improved functional independence in patients with endovascular revascularization, and the association was not time-dependent.

Endovascular Therapy of M2 Occlusion in IMS III: Role of M2 Segment Definition and Location on Clinical and Revascularization Outcomes

BACKGROUND AND PURPOSE

Uncertainty persists regarding the safety and efficacy of endovascular therapy of M2 occlusions following IV tPA. We reviewed the impact of revascularization on clinical outcomes in 83 patients with M2 occlusions in the Interventional Management of Stroke III trial according to specific M1-M2 segment anatomic features.

MATERIALS AND METHODS

Perfusion of any M2 branch distinguished M2-versus-M1 occlusion. Prespecified modified TICI and arterial occlusive lesion revascularization and clinical mRS 0-2 end points at 90 days for endovascular therapy-treated M2 occlusions were analyzed. Post hoc analyses of the relationship of outcomes to multiple baseline angiographic M2 and M1 subgroup characteristics were performed.

RESULTS

Of 83 participants with M2 occlusion who underwent endovascular therapy, 41.0% achieved mRS 0-2 at 90 days, including 46.6% with modified TICI 2-3 reperfusion compared with 26.1% with modified TICI 0-1 reperfusion (risk difference, 20.6%; 95% CI, -1.4%-42.5%). mRS 0-2 outcome was associated with reperfusion for M2 trunk (n = 9) or M2 division (n = 42) occlusions, but not for M2 branch occlusions (n = 28). Of participants with trunk and division occlusions, 63.2% with modified TICI 2a and 42.9% with modified TICI 2b reperfusion achieved mRS 0-2 outcomes; mRS 0-2 outcomes for M2 trunk occlusions (33%) did not differ from distal (38.2%) and proximal (26.9%) M1 occlusions.

CONCLUSIONS

mRS 0-2 at 90 days was dependent on reperfusion for M2 trunk but not for M2 branch occlusions. For M2 division occlusions, good outcome with modified TICI 2b reperfusion did not differ from that in modified TICI 2a. M2 segment definition and occlusion location may contribute to differences in revascularization and good outcome between Interventional Management of Stroke III and other endovascular therapy studies.

Increased admission and fasting glucose are associated with unfavorable short-term outcome after intra-arterial treatment of ischemic stroke in the MR CLEAN pretrial cohort

BACKGROUND

Limited data are available on the impact of fasting glucose on outcome after intra-arterial treatment (IAT). We studied whether hyperglycemia on admission and impaired fasting glucose (IFG) are associated with unfavorable outcome after IAT in acute ischemic stroke.

METHODS

Patients were derived from the pretrial registry of the MR CLEAN-trial. Hyperglycemia on admission was defined as glucose>7.8mmol/L, IFG as fasting glucose>5.5mmol/L in the first week of admission. Primary effect measure was the adjusted common odds ratio (acOR) for a shift in the direction of worse outcome on the modified Rankin Scale at discharge, estimated with ordinal logistic regression, adjusted for common prognostic factors.

RESULTS

Of the 335 patients in which glucose on admission was available, 86 (26%) were hyperglycemic, 148 of the 240 patients with available fasting glucose levels (62%) had IFG. Median admission glucose was 6.8mmol/L (IQR 6-8). Increased admission glucose (acOR 1.2, 95%CI 1.1-1.3), hyperglycemia on admission (acOR 2.6, 95%CI 1.5-4.6) and IFG (acOR 2.8, 95%CI 1.4-5.6) were associated with worse functional outcome at discharge.

CONCLUSION

Increased glucose on admission and IFG in the first week after stroke onset are associated with unfavorable short-term outcome after IAT of acute ischemic stroke.

A Direct Aspiration, First Pass Technique (ADAPT) versus Stent Retrievers for Acute Stroke Therapy: An Observational Comparative Study

BACKGROUND AND PURPOSE

Mechanical thrombectomy with stent retrievers is now the standard therapy for selected patients with ischemic stroke. The technique of A Direct Aspiration, First Pass Technique for the Endovascular Treatment of Stroke (ADAPT) appears promising with a high rate of recanalization. We compared ADAPT versus stent retrievers (the Solitaire device) for efficacy and safety as a front-line endovascular procedure.

MATERIALS AND METHODS

We analyzed 243 consecutive patients with large intracranial artery occlusions of the anterior circulation, treated within 6 hours with mechanical thrombectomy by either ADAPT or the Solitaire stent. Th primary outcome was complete recanalization (modified TICI ≥ 2b); secondary outcomes included complication rates and procedural and clinical outcomes.

RESULTS

From November 2012 to June 2014, 119 patients were treated with stent retriever (Solitaire FR) and 124 by using the ADAPT with Penumbra reperfusion catheters. The median baseline NIHSS score was the same for both groups (Solitaire, 17 [interquartile range, 11-21] versus ADAPT, 17 [interquartile range, 12-21]). Time from groin puncture to recanalization (Solitaire, 50 minutes [range, 25-80 minutes] versus ADAPT, 45 minutes [range, 27-70 minutes], P = .42) did not differ significantly. However, compared with the Solitaire group, patients treated with ADAPT achieved higher final recanalization rates (82.3% versus 68.9%; adjusted relative risk, 1.18; 95% CI, 1.02-1.37; P = .022), though differences in clinical outcomes between the cohorts were not significant. Use of an adjunctive device was more frequent in the ADAPT group (45.2% versus 13.5%, P < .0001). The rate of embolization in new territories or symptomatic hemorrhage did not differ significantly between the 2 groups.

CONCLUSIONS

Front-line ADAPT achieved higher recanalization rates than the Solitaire device. Further randomized controlled trials are warranted to define the best strategy for mechanical thrombectomy.

Expanding the concept of neuroprotection for acute ischemic stroke: The pivotal roles of reperfusion and the collateral circulation

This review surveys the efforts taken to achieve clinically efficacious protection of the ischemic brain and underscores the necessity of expanding our purview to include the essential role of cerebral perfusion and the collateral circulation. We consider the development of quantitative strategies to measure cerebral perfusion at the regional and local levels and the application of these methods to elucidate flow-related thresholds of ischemic viability and to characterize the ischemic penumbra. We stress that the modern concept of neuroprotection must consider perfusion, the necessary substrate upon which ischemic brain survival depends. We survey the major mechanistic approaches to neuroprotection and review clinical neuroprotection trials, focusing on those phase 3 multicenter clinical trials for acute ischemic stroke that have been completed or terminated. We review the evolution of thrombolytic therapies; consider the lessons learned from the initial, negative multicenter trials of endovascular therapy; and emphasize the highly successful positive trials that have finally established a clinical role for endovascular clot removal. As these studies point to the brain's collateral circulation as key to successful reperfusion, we next review the anatomy and pathophysiology of collateral perfusion as it relates to ischemic infarction, as well as the molecular and genetic influences on collateral development. We discuss the current MR and CT-based diagnostic methods for assessing the collateral circulation and the prognostic significance of collaterals in ischemic stroke, and we consider past and possible future therapeutic directions.

Automated CT Perfusion for Ischemic Core Volume Prediction in Tandem Anterior Circulation Occlusions

BACKGROUND/AIM

CT perfusion (CTP) predicts ischemic core volumes in acute ischemic stroke (AIS); however, assumptions made within the pharmacokinetic model may engender errors by the presence of tracer delay or dispersion. We aimed to evaluate the impact of hemodynamic disturbance due to extracranial anterior circulation occlusions upon the accuracy of ischemic core volume estimation with an automated perfusion analysis tool (RAPID) among AIS patients with large-vessel occlusions.

METHODS

A prospectively collected, interventional database was retrospectively reviewed for all cases of endovascular treatment of AIS between September 2010 and March 2015 for patients with anterior circulation occlusions with baseline CTP and full reperfusion (mTICI3).

RESULTS

Out of 685 treated patients, 114 fit the inclusion criteria. Comparison between tandem (n = 21) and nontandem groups (n = 93) revealed similar baseline ischemic core (20 ± 19 vs. 19 ± 25 cm(3); p = 0.8), Tmax >6 s (175 ± 109 vs. 162 ± 118 cm(3); p = 0.6), Tmax >10 s (90 ± 84 vs. 90 ± 91 cm(3); p = 0.9), and final infarct volumes (45 ± 47 vs. 37 ± 45 cm(3); p = 0.5). Baseline core volumes were found to correlate with final infarct volumes for the tandem (r = 0.49; p = 0.02) and nontandem (r = 0.44; p < 0.01) groups. The mean absolute difference between estimated core and final infarct volume was similar between patients with and those without (24 ± 41 vs. 17 ± 41 cm(3); p = 0.5) tandem lesions.

CONCLUSIONS

The prediction of baseline ischemic core volumes through an optimized CTP analysis employing rigorous normalization, thresholding, and voxel-wise analysis is not significantly influenced by the presence of underlying extracranial carotid steno-occlusive disease in large-vessel AIS.

Repeated Mechanical Thrombectomy in Recurrent Large Vessel Occlusion Acute Ischemic Stroke

BACKGROUND

Endovascular therapy has been proven effective for the treatment of large vessel occlusion strokes (LVOS). However, the feasibility and potential benefits of repeat thrombectomy for recurrent stroke is unclear. We aim to report our experience with repeat thrombectomy for recurrent LVOS.

METHODS

We reviewed our prospectively collected endovascular database for patients who underwent repeated mechanical thrombectomy. Baseline characteristics, procedural data and outcomes were evaluated. Patients with repeat thrombectomy were compared to patients with single thrombectomy. For patients with repeat thrombectomy, imaging and procedural variables were compared between first and last procedures.

RESULTS

Out of 697 patients treated within the study period, 15 patients (2%) had repeat thrombectomies (14 treated twice and one thrice). The mean age was 63 ± 15 years and 40% were males. The median time between the first and last procedure was 18 (1-278) days. Cardioembolism (66%) was the most common etiology, followed by intracranial atherosclerosis (13%) and large vessel atherosclerosis (6%). At 90 days after the last thrombectomy, 60% of patients achieved a modified Rankin Scale score of 0-2 and 20% were deceased. There were no statistically significant differences in demographics, stroke severity, time from last known normal to puncture, reperfusion rates, hemorrhagic complications, good clinical outcomes and mortality between patients who underwent repeat thrombectomy and those who had a single thrombectomy.

CONCLUSION

In properly selected patients suffering recurrent LVOS, repeated mechanical thrombectomy appears to be feasible and safe. A previous thrombectomy should not discourage aggressive treatment as these patients may achieve similar rates of good clinical outcomes as those who undergo single thrombectomy.

Too good to intervene? Thrombectomy for large vessel occlusion strokes with minimal symptoms: an intention-to-treat analysis

INTRODUCTION

The minimal stroke severity justifying endovascular intervention remains elusive; however, a significant proportion of patients presenting with large vessel occlusion (LVO) and mild symptoms subsequently decline and face poor outcomes.

OBJECTIVE

To evaluate our experience with these patients by comparing best medical therapy with thrombectomy in an intention-to-treat analysis.

METHODS

Analysis of prospectively collected data of all consecutive patients with National Institutes of Health Stroke Scale (NIHSS) score ≤5, LVO on CT angiography, and baseline modified Rankin Scale (mRS) score 0-2 from November 2014 to May 2016. After careful discussion with patients/family, a decision to pursue medical or interventional therapy was made. Deterioration (development of aphasia, neglect, and/or significant weakness) triggered reconsideration of thrombectomy. The primary outcome measure was NIHSS shift (discharge NIHSS score minus admission NIHSS score).

RESULTS

Of the 32 patients qualifying for the study, 22 (69%) were primarily treated with medical therapy and 10 (31%) intervention. Baseline characteristics were comparable. Nine (41%) medically treated patients had subsequent deterioration requiring thrombectomy. Median time from arrival to deterioration was 5.2 hours (2.0-25.0). Successful reperfusion (modified Treatment in Cerebral Infarction 2b-3) was achieved in all 19 thrombectomy patients. The NIHSS shift significantly favored thrombectomy (-2.5 vs 0; p<0.01). The median NIHSS score at discharge was low with both thrombectomy (1 (0-3)) and medical therapy (2 (0.5-4.5)). 90-Day mRS 0-2 rates were 100% and 77%, respectively (p=0.15). Multivariable linear regression indicated that thrombectomy was independently associated with a beneficial NIHSS shift (unstandardized β -4.2 (95% CI -8.2 to -0.1); p=0.04).

CONCLUSIONS

Thrombectomy led to a shift towards a lower NIHSS in patients with LVO presenting with minimal stroke symptoms. Despite the overall perception that this condition is benign, nearly a quarter of patients primarily treated with medical therapy did not achieve independence at 90 days.

Collateral state and the effect of endovascular reperfusion therapy on clinical outcome in ischemic stroke patients

PURPOSE

Clinically successful endovascular therapy (EVT) in ischemic stroke requires reliable noninvasive pretherapeutic selection criteria. We investigated the association of imaging parameters including CT angiographic collaterals and degree of reperfusion with clinical outcome after EVT.

METHODS

In our database, we identified 93 patients with large vessel occlusion in the anterior circulation treated with EVT. Besides clinical data, we assessed the baseline Alberta Stroke Program Early CT score (ASPECTS) on noncontrast CT (NCCT) and CT angiography (CTA) source images, collaterals (CT-CS) and clot burden score (CBS) on CTA and the degree of reperfusion after EVT on angiography. Three readers, blinded to clinical information, evaluated the images in consensus. Data-driven multivariable ordinal regression analysis identified predictors of good outcome after 90 days as measured with the modified Rankin Scale.

RESULTS

Successful angiographic reperfusion (OR 26.50; 95%-CI 9.33-83.61) and good collaterals (OR 9.69; 95%-CI 2.28-59.27) were independent predictors of favorable outcome along with female sex (OR 0.35; 95%-CI 0.14-0.85), younger age (OR 0.88; 95%-CI 0.83-0.92) and higher NCCT ASPECTS (OR 2.54; 95%-CI 1.01-6.63). Outcome was best in patients with good collaterals and successful reperfusion, but there was no statistical interaction between collaterals and reperfusion.

CONCLUSIONS

CTA-collateral status was the strongest pretherapeutic predictor of favorable outcome in ischemic stroke patients treated with EVT. CTA-collaterals are thus well suited for patient selection in EVT. However, the independent effect of reperfusion on outcome tended to be stronger than that of CTA-collaterals.

Automated CT Perfusion Ischemic Core Volume and Noncontrast CT ASPECTS (Alberta Stroke Program Early CT Score)

Background and Purpose—

The semiquantitative noncontrast CT Alberta Stroke Program Early CT Score (ASPECTS) and RAPID automated computed tomography (CT) perfusion (CTP) ischemic core volumetric measurements have been used to quantify infarct extent. We aim to determine the correlation between ASPECTS and CTP ischemic core, evaluate the variability of core volumes within ASPECTS strata, and assess the strength of their association with clinical outcomes.

Methods—

Review of a prospective, single-center database of consecutive thrombectomies of middle cerebral or intracranial internal carotid artery occlusions with pretreatment CTP between September 2010 and September 2015. CTP was processed with RAPID software to identify ischemic core (relative cerebral blood flow<30% of normal tissue).

Results—

Three hundred and thirty-two patients fulfilled inclusion criteria. Median age was 66 years (55–75), median ASPECTS was 8 (7–9), whereas median CTP ischemic core was 11 cc (2–27). Median time from last normal to groin puncture was 5.8 hours (3.9–8.8), and 90-day modified Rankin scale score 0 to 2 was observed in 54%. The correlation between CTP ischemic core and ASPECTS was fair ( R =−0.36; P <0.01). Twenty-six patients (8%) had ASPECTS <6 and CTP core ≤50 cc (37% had modified Rankin scale score 0–2, whereas 29% were deceased at 90 days). Conversely, 27 patients (8%) had CTP core >50 cc and ASPECTS ≥6 (29% had modified Rankin scale 0–2, whereas 21% were deceased at 90 days). Moderate correlations between ASPECTS and final infarct volume ( R =−0.42; P <0.01) and between CTP ischemic core and final infarct volume ( R =0.50; P <0.01) were observed; coefficients were not significantly influenced by the time from stroke onset to presentation. Multivariable regression indicated ASPECTS ≥6 (odds ratio 4.10; 95% confidence interval, 1.47–11.46; P =0.01) and CTP core ≤50 cc (odds ratio 3.86; 95% confidence interval, 1.22–12.15; P =0.02) independently and comparably predictive of good outcome.

Conclusions—

There is wide variability of CTP-derived core volumes within ASPECTS strata. Patient selection may be affected by the imaging selection method.

Aspiration Thrombectomy After Intravenous Alteplase Versus Intravenous Alteplase Alone

Background and Purpose—

Thrombectomy, primarily with stent retrievers with or without adjunctive aspiration, provided clinical benefit across multiple prospective randomized trials. Whether this benefit is exclusive to stent retrievers is unclear.

Methods—

THERAPY (The Randomized, Concurrent Controlled Trial to Assess the Penumbra System’s Safety and Effectiveness in the Treatment of Acute Stroke; NCT01429350) was an international, multicenter, prospective, randomized (1:1), open label, blinded end point evaluation, concurrent controlled clinical trial of aspiration thrombectomy after intravenous alteplase (IAT) administration compared with intravenous-alteplase alone in patients with large vessel ischemic stroke because of a thrombus length of ≥8 mm. The primary efficacy end point was the percent of patients achieving independence at 90 days (modified Rankin Scale score, 0–2; intention-to-treat analysis). The primary safety end point was the rate of severe adverse events (SAEs) by 90 days (as treated analysis). Patients were randomized 1:1 across 36 centers in 2 countries (United States and Germany).

Results—

Enrollment was halted after 108 (55 IAT and 53 intravenous) patients (of 692 planned) because of external evidence of the added benefit of endovascular therapy to intravenous-alteplase alone. Functional independence was achieved in 38% IAT and 30% intravenous intention-to-treat groups ( P =0.52). Intention-to-treat ordinal modified Rankin Scale odds ratio was 1.76 (95% confidence interval, 0.86–3.59; P =0.12) in favor of IAT. Secondary efficacy analyses all demonstrated a consistent direction of effect toward benefit of IAT. No differences in symptomatic intracranial hemorrhage rates (9.3% IAT versus 9.7% intravenous, P =1.0) or 90-day mortality (IAT: 12% versus intravenous: 23.9%, P =0.18) were observed.

Conclusions—

THERAPY did not achieve its primary end point in this underpowered sample. Directions of effect for all prespecified outcomes were both internally and externally consistent toward benefit. It is possible that an alternate method of thrombectomy, primary aspiration, will benefit selected patients harboring large vessel occlusions. Further study on this topic is indicated.

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov . Unique identifier: NCT01429350.

Emergent revascularization of acute tandem vertebrobasilar occlusions: Endovascular approaches and technical considerations-Confirming the role of vertebral artery ostium stenosis as a cause of vertebrobasilar stroke

Patients suffering from acute atherothrombotic occlusion of the proximal vertebral artery (VA) and concomitant basilar artery (BA) occlusion present a grim prognosis. We describe our experience in the endovascular recanalization of tandem vertebrobasilar occlusions using endovascular techniques. The BA was accessed through the normal VA (clean-road) or the occluded, thrombotic VA (dirty-road), and stentriever-based thrombectomy was performed using antegrade or reverse revascularization variants. Seven patients underwent successful stentriever-assisted mechanical thrombectomy of the BA and five sustained concomitant VA revascularization. Stroke onset to endovascular intervention initiation (time-to-treatment) ranged from 4.5-13hours (mean 8.6). In two of seven patients, the BA occlusion was approached with a 'clean-road' approach via the contralateral VA; in five of seven patients, a 'dirty-road' approach via the occluded VA was used. Mean time-to-recanalization was 66minutes (range 55-82). There were no perforations, iatrogenic vessel dissections, or other technical complications. Four patients presented mild-to-moderate disability (modified Rankin Scale [mRS] 0-3) at 3months, one remained with moderate-to-severe disability (mRS 4), and two patients died on days 9 and 23 after their strokes. Follow-up ranged from 6-45months (mean 24months). In selected patients with acute VA-BA occlusion, stentriever-based thrombectomy performed through either the patent or the occluded VA, may be feasible, effective, and safe. Clinical outcomes in these patients seem to equipoise the neurological outcome of patients with successful revascularization for isolated BA occlusion. This unique pair of occlusions confirms the role of VA ostium stenosis as a cause of vertebrobasilar stroke.

[Technical standards for the interventional treatment of acute ischemic stroke]

Acute ischemic stroke is the leading cause of acquired disability and its treatment is still a major challenge. For more than a decade, various mechanical devices have been developed for the recanalization of proximal artery occlusions in acute ischemic stroke but most of them have been approved for clinical use, only on the basis of uncontrolled case series. Intravenous thrombolysis with recombinant tissue-specific plasminogen activator administered (iv rtPA) within 4.5 h of symptom onset is so far the only approved medicinal treatment in the acute phase of cerebral infarction. With the introduction of stent retrievers, mechanical thrombectomy has demonstrated substantial rates of partial or complete arterial recanalization and improved outcomes compared with iv rtPA and best medical treatment alone in multiple randomized clinical trials in select patients with acute ischemic stroke and proximal artery occlusions. This review discusses the evolution of endovascular stroke therapy followed by a discussion of the current technical standards of mechanical thrombectomy that have to be considered during endovascular stroke therapy and the updated treatment recommendations of the ESO Karolinska stroke update.

Internal Carotid Artery S-Shaped Curve as a Marker of Fibromuscular Dysplasia in Dissection-Related Acute Ischemic Stroke

BACKGROUND AND PURPOSE

Craniocervical fibromuscular dysplasia (FMD) is associated with dissections and with S-shaped curves in the internal carotid artery (ICA). We evaluated the occurrence of S-curves in patients presenting with acute strokes due to ICA steno-occlusive dissections.

METHODS

This was a retrospective review of the interventional databases of two academic tertiary-care institutions. The presence of ICA S-shaped curves, C-shaped curves, 360-degree loops, as well as classic FMD and atherosclerotic changes at the ICA bulb and curve/loop was determined. Cases of carotid dissections were compared with a control group (consecutive non-tandem anterior circulation strokes).

RESULTS

Twenty-four patients with carotid dissections were compared to 92 controls. Baseline characteristics and procedural variables were similar, with the exception of younger age, less frequent history of hypertension, diabetes, atrial fibrillation and stent retriever use in patients with dissections. The rates of mTICI2b-3 reperfusion, parenchymal hematoma, good outcome and mortality were similar amongst groups. The frequency of S-curves (any side without superimposed atherosclerosis) was 29% in the dissection group versus 7% in controls (p < 0.01). S-curves were typically mirror images within the dissection group (85% had bilateral occurrence). The frequency of C-shaped and 360-degree curves was similar between groups. FMD changes within the craniocervical arteries were statistically more common in dissection patients. Ten patients (41%) of the dissection group had S-curves or classic FMD changes. Multivariate analysis indicated that S-curves were independently associated with the presence of dissections.

CONCLUSION

S-shaped ICA curves are predictably bilateral, highly associated with carotid dissections in patients with moderate to severe strokes, and may suggest an underlying presence of FMD.

Is Intra-Arterial Treatment for Acute Ischemic Stroke Less Effective in Women than in Men?

INTRODUCTION

Stroke etiology and outcome after ischemic stroke differ between men and women. We examined if sex modifies the effect of intra-arterial treatment (IAT) in a randomized clinical trial of IAT for acute ischemic stroke in the Netherlands (MR CLEAN).

PATIENTS AND METHODS

The primary outcome was the score on the modified Rankin scale at 90 days. We tested for interaction between sex and treatment and estimated the treatment effect by sex with multiple ordinal logistic regression with adjustment for prognostic factors.

RESULTS

All 500 patients were included in the analysis; 292 (58.4%) were men. The treatment effect (adjusted common odds ratio) was 2.39 [95% confidence interval (CI) 1.55-3.68] in men and 0.99 (95% CI 0.60-1.66) in women (p_interaction = 0.016). In women, mortality was higher in the intervention group than in the control group (24 vs. 15%, p = 0.07). Serious adverse events occurred more often in women than in men undergoing intervention. There were no differences in neuro-imaging outcomes.

DISCUSSION AND CONCLUSION

Contrary to other studies, we found a significant interaction between sex and treatment effect in the MR CLEAN trial. Pooled analyses of all published thrombectomy trials did not confirm this finding. In MR CLEAN, women seem to have a slightly more unfavorable profile, causing higher mortality and more serious adverse events, but insufficient to explain the absence of an overall effect. This suggests a play of chance and makes it clear that IAT should not be withheld in women.

Ultra-distal access of the M1 segment with the 5 Fr Navien distal access catheter in acute (anterior circulation) stroke: is it safe and efficient?

BACKGROUND AND AIM

The importance of mechanical thrombectomy in acute stroke treatment has grown over recent years. Mechanical thrombectomy comprises many different techniques. Technical improvements in the catheter material have led to the development of large-bore distal access catheters which can enter tortuous intracranial vessels. This has promising applications for endovascular stroke treatment. This study evaluated the safety and success rate of ultra-distal access of the middle cerebral artery (MCA) M1 segment with the 5 Fr Navien 58 distal access catheter in the treatment of acute stroke in combination with stent retrievers.

METHODS

We retrospectively analyzed 81 patients with an acute stroke of the anterior circulation in whom ultra-distal access to the M1 segment was carried out using the Navien 58 catheter with an anchoring technique with a stent retriever for mechanical thrombectomy. Technical complications, success rates of catheter placement, success rates of thrombectomy using the modified Thrombolysis In Cerebral Infarction (mTICI) score, and the procedure times were evaluated.

RESULTS

Ultra-distal access with the Navien 58 was successful in 75% (61/81) of cases. Recanalization success with a mTICI score of 2b and better was achieved in 83% overall (67/81), in 90% (55/61) of cases with successful ultra-distal access and in 60% (12/20) of cases without ultra-distal access. No severe adverse effects such as dissections or perforations occurred as a result of the ultra-distal catheter placement in the M1 segment. In 4% (3/81) of the cases a reversible MCA vasospasm occurred.

CONCLUSIONS

Ultra-distal placement of the Navien 58 distal access catheter into the M1 segment in acute anterior circulation stroke can be achieved consistently, is safe in practice, and results in good recanalization success rates.

Recanalization and Angiographic Reperfusion Are Both Associated with a Favorable Clinical Outcome in the IMS III Trial

BACKGROUND

Prompt revascularization is the main goal of acute ischemic stroke treatment. We examined which revascularization scale - reperfusion (modified Treatment in Cerebral Infarctions, mTICI) or recanalization (Arterial Occlusive Lesion, AOL) - better predicted the clinical outcome in ischemic stroke participants treated with endovascular therapy (EVT). Additionally, we determined the optimal thresholds for the predictive accuracy of each scale.

METHODS

We included participants from the Interventional Management of Stroke (IMS) III trial with complete occlusion in the internal carotid artery terminus or proximal middle cerebral artery (M1 or M2) who completed EVT within 7 h of symptom onset. The abilities of the AOL and mTICI scales to predict a favorable outcome (defined as a modified Rankin Scale score of 0-2 at 3 months) were compared by receiver operating characteristic analyses. The maximal sensitivity and specificity for each revascularization scale were established.

RESULTS

Among 240 participants who met the study inclusion criteria, 79 (33%) achieved a favorable outcome. Higher scores of mTICI and AOL increased the likelihood of a favorable outcome (2.7% with mTICI 0 vs. 83.3% with mTICI 3, and 3.0% with AOL 0 vs. 43% with AOL 3). The accuracy of mTICI reperfusion and AOL recanalization for a favorable outcome prediction was similar, with optimal thresholds of mTICI 2b/3 and AOL 3, respectively.

CONCLUSION

Reperfusion (mTICI) and recanalization (AOL) predicted a favorable clinical outcome with comparable accuracy in ischemic stroke participants treated with EVT. Optimal revascularization goals to maximize clinical outcome (modified Rankin Scale score of 0-2) consisted of complete recanalization (AOL 3) and reperfusion of at least 50% of the arterial tree of the symptomatic artery (mTICI 2b/3) in the IMS III trial setting.