Efficacy of Peripheral Interventional Radiologists Performing Endovascular Stroke Therapy Guided by CT Perfusion Triage of Patients

PurposeTo assess safety and efficacy of intraarterial mechanical thrombectomy for treatment of ischemic stroke in a community hospital by peripheral interventional radiologists employing computed tomography (CT) perfusion imaging for patient selection.Materials and MethodsForty patients, 11 men (27.5%) and 29 women (72.5%), were treated between February 2008 and October 2011. Eligible patients had a National Institutes of Health Stroke Scale (NIHSS) score greater than 8 and diagnosis of large-vessel ischemic stroke by head CT angiogram, and met previously reported CT perfusion imaging triage criteria.ResultsThe baseline NIHSS score was 18.0 ± 7.9 (range, 8–35). Sixteen patients (40%) had a baseline NIHSS score greater than 20. Symptom onset was unknown in five patients. Symptom onset to device time in the remaining 35 patients was 254.8 minutes ± 150.9 (range, 75–775 min). A total of 65% of patients showed thrombolysis in cerebral infarction (TICI) 2a, 2b, or 3 flow following the procedure. Symptomatic intracranial hemorrhage was seen in four patients (10.0%). At 90 days, 32 patients (80%) were alive and eight (20%) had died. The modified Rankin scale (mRS) score at 90 days was no more than 2 in 20 patients (50.0%). The mean mRS score at 90 days was 2.9 ± 2.0 (range, 0–6). NIHSS score at 90 days was 5.1 ± 6.1 (range, 0–24). In patients with successful recanalization (ie, TICI 2 or 3 flow), a good clinical outcome (ie, mRS score ≤ 2) was achieved in 65.3% of patients (mean, 2.4 ± 1.9; range, 0–6), and 90-day mortality rate was 15.4%, compared with 28.6% in patients with TICI 0/1 flow.ConclusionsPeripheral interventional radiologists who use CT perfusion imaging for patient triage can have good neurologic outcomes and provide sustainable, safe, and complete around-the-clock coverage for endovascular stroke treatment.     

Texture analysis based on ADC maps and T2-FLAIR images for the assessment of the severity and prognosis of ischaemic stroke

ObjectivesTo explore the feasibility of texture analysis based on T2-weighted fluid-attenuated inversion recovery (T2-FLAIR) images and apparent diffusion coefficient (ADC) maps in the assessment of the severity and prognosis of ischaemic stroke using the National Institutes of Health Stroke Scale (NIHSS) and modified Rankin scale (mRS) scores, respectively.MethodsOverall, 116 patients diagnosed with subacute ischaemic stroke were included in this retrospective study. Based on T2-FLAIR images and ADC maps, 15 texture features were extracted from the ROIs of each patient using grey-level co-occurrence matrix (GLCM) and local binary pattern histogram Fourier (LBP-HF) methods. The correlations of NIHSS score on admission (NIHSS_baseline), NIHSS score 24 h after stroke onset (NIHSS_24h) and mRS score with the texture features were evaluated using Spearman's partial correlations. The receiver operating characteristic (ROC) curve was used to compare the performance of the selected texture features in the evaluation of stroke severity and prognosis.ResultsTexture features derived from the T2-FLAIR images and ADC maps were correlated with NIHSS score and mRS score. Entropy_ADC and 0.75Quantile_T2-FLAIR showed the best diagnostic performance for assessing stroke severity. The combination of Entropy_ADC and 0.75Quantile_T2-FLAIR achieved a better performance in the evaluation of stroke severity (AUC = 0.7, p = 0.01) than either feature alone. Only 0.05Quantile_T2-FLAIR was found to be correlated with mRS score, and none of the texture features were predictive of mRS score.ConclusionTexture features derived from T2-FLAIR images and ADC maps might serve as biomarkers to evaluate stroke severity, but were insufficient to predict stroke prognosis.     

Feasibility of a Clinical-Radiomics Model to Predict the Outcomes of Acute Ischemic Stroke

ObjectiveTo develop a model incorporating radiomic features and clinical factors to accurately predict acute ischemic stroke (AIS) outcomes.Materials and MethodsData from 522 AIS patients (382 male [73.2%]; mean age ± standard deviation, 58.9 ± 11.5 years) were randomly divided into the training (n = 311) and validation cohorts (n = 211). According to the modified Rankin Scale (mRS) at 6 months after hospital discharge, prognosis was dichotomized into good (mRS ≤ 2) and poor (mRS > 2); 1310 radiomics features were extracted from diffusion-weighted imaging and apparent diffusion coefficient maps. The minimum redundancy maximum relevance algorithm and the least absolute shrinkage and selection operator logistic regression method were implemented to select the features and establish a radiomics model. Univariable and multivariable logistic regression analyses were performed to identify the clinical factors and construct a clinical model. Ultimately, a multivariable logistic regression analysis incorporating independent clinical factors and radiomics score was implemented to establish the final combined prediction model using a backward step-down selection procedure, and a clinical-radiomics nomogram was developed. The models were evaluated using calibration, receiver operating characteristic (ROC), and decision curve analyses.ResultsAge, sex, stroke history, diabetes, baseline mRS, baseline National Institutes of Health Stroke Scale score, and radiomics score were independent predictors of AIS outcomes. The area under the ROC curve of the clinical-radiomics model was 0.868 (95% confidence interval, 0.825–0.910) in the training cohort and 0.890 (0.844–0.936) in the validation cohort, which was significantly larger than that of the clinical or radiomics models. The clinical radiomics nomogram was well calibrated (p > 0.05). The decision curve analysis indicated its clinical usefulness.ConclusionThe clinical-radiomics model outperformed individual clinical or radiomics models and achieved satisfactory performance in predicting AIS outcomes.     

Dodecafluoropentane emulsion decreases infarct volume in a rabbit ischemic stroke model

PurposeTo assess the efficacy of dodecafluoropentane emulsion (DDFPe), a nanodroplet emulsion with significant oxygen transport potential, in decreasing infarct volume in an insoluble-emboli rabbit stroke model.Materials And MethodsNew Zealand White rabbits (N = 64; weight, 5.1 ± 0.50 kg) underwent angiography and received embolic spheres in occluded internal carotid artery branches. Rabbits were randomly assigned to groups in 4-hour and 7-hour studies. Four-hour groups included control (n = 7, embolized without treatment) and DDFPe treatment 30 minutes before stroke (n = 7), at stroke onset (n = 8), and 30 minutes (n = 5), 1 hour (n = 7), 2 hours (n = 5), or 3 hours after stroke (n = 6). Seven-hour groups included control (n = 6) and DDFPe at 1 hour (n = 8) and 6 hours after stroke (n = 5). DDFPe dose was a 2% weight/volume intravenous injection (0.6 mL/kg) repeated every 90 minutes as time allowed. After euthanasia, infarct volume was determined by vital stains on brain sections.ResultsAt 4 hours, median infarct volume decreased for all DDFPe treatment times (pretreatment, 0.30% [P = .004]; onset, 0.20% [P = .004]; 30 min, 0.35% [P = .009]; 1 h, 0.30% [P = .01]; 2 h, 0.40% [P = .009]; and 3 h, 0.25% [P = .003]) compared with controls (3.20%). At 7 hours, median infarct volume decreased with treatment at 1 hour (0.25%; P = .007) but not at 6 hours (1.4%; P = .49) compared with controls (2.2%).ConclusionsIntravenous DDFPe in an animal model decreases infarct volumes and protects brain tissue from ischemia, justifying further investigation.     

Balloon Guide Catheter in Endovascular Treatment for Acute Ischemic Stroke: Results from the MR CLEAN Registry

PurposeTo compare outcomes after endovascular treatment (EVT) for acute ischemic stroke with and without the use of a balloon guide catheter (BGC) in clinical practice.Materials and MethodsData from the Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in The Netherlands (MR CLEAN) Registry were used, in which all patients who underwent EVT for anterior-circulation stroke in The Netherlands between 2014 and 2016 were enrolled. Primary outcome was modified Rankin scale (mRS) score at 90 days. Secondary outcomes included reperfusion grade (extended Thrombolysis In Cerebral Infarction [eTICI] score) and National Institutes of Health Stroke Scale (NIHSS) score 24–48 hours after intervention. The association between the use of a BGC and outcomes was estimated with logistic regression adjusted for age, sex, prestroke mRS score, NIHSS score, collateral grade, and time from onset to EVT.ResultsA total of 887 patients were included. Thrombectomy was performed with the use of a BGC in 528 patients (60%) and without in 359 patients (40%). There was no significant association between use of a BGC and a shift on the mRS toward better outcome (adjusted common odds ratio, 1.17; 95% confidence interval [CI], 0.91–1.52). Use of a BGC was associated with higher eTICI score (adjusted common OR, 1.33; 95% CI, 1.04–1.70) and improvement of ≥ 4 points on the NIHSS (adjusted OR, 1.40; 95% CI, 1.04–1.88).ConclusionsIn clinical practice, use of a BGC was associated with higher reperfusion grade and early improvement of neurologic deficits, but had no positive effect on long-term functional outcome.     

Predictors of clinical outcome in patients receiving local intra-arterial thrombolysis without subsequent symptomatic intracranial hemorrhage against acute middle cerebral artery occlusion

BACKGROUND AND PURPOSE: The factors that predict favorable outcome after local intra-arterial thrombolysis (LIT) remain unknown. We aimed to clarify these factors in patients with middle cerebral artery occlusion treated by LIT. METHODS: We performed LIT in 26 consecutive patients who had middle cerebral artery occlusion with a modified Rankin scale (mRS) score or=3). RESULTS: The duration from symptom onset to hospital admission was 0.96 +/- 0.87 (mean +/- SD) hour and from onset of stroke to LIT was 3.78 +/- 1.17 hours. No patients developed symptomatic intracerebral hemorrhage or died. Thirteen patients achieved good outcomes. No significant differences existed between the two groups in baseline National Institutes of Health Stroke Scale (NIHSS) scores, time from stroke onset to LIT, blood pressure, early CT signs, or subsequent hemorrhagic transformation shown by CT. However, univariate analysis showed that patients with good outcomes were younger, more often had absence of hypertension history, had better collaterals shown by angiography, and had better recanalization rates than those with poor outcomes. NIHSS scores after LIT were lower in patients with good outcomes than in patients with poor outcomes. Logistic regression analysis indicated improvement of the NIHSS scores by >or=2 immediately after LIT was independently associated with good outcome. CONCLUSION: Improvement of the NIHSS score by >or=2 immediately after LIT is a useful predictor of patient outcome at discharge.     

Acute Combined Revascularization in Acute Ischemic Stroke with Intracranial Arterial Occlusion: Self-expanding Solitaire Stent during Intravenous Thrombolysis

PurposeTo investigate the safety and efficacy of the self-expanding Solitaire stent used during intravenous thrombolysis (IVT) for intracranial arterial occlusion (IAO) in acute ischemic stroke (AIS).Materials and MethodsConsecutive nonselected patients with AIS with IAO documented on computed tomographic angiography or magnetic resonance angiography and treated with IVT were included in this prospective study. Stent intervention was initiated and performed during administration of IVT without waiting for any clinical or radiologic signs of potential recanalization. Stroke severity was assessed by National Institutes of Health Stroke Scale (NIHSS), and 90-day clinical outcome was assessed by modified Rankin scale (mRS), with a good outcome defined as an mRS score of 0–2. Recanalization was rated by thrombolysis in cerebral infarction (TICI) scale.ResultsFifty patients (mean age, 66.8 y ± 14.6) had a baseline median NIHSS score of 18.0. Overall recanalization was achieved in 94% of patients, and complete recanalization (ie, TICI 3 flow) was achieved in 72% of patients. The mean time from stroke onset to maximal recanalization was 244.2 minutes ± 87.9, with a median of 232.5 minutes. The average number of device passes was 1.5, with a mean procedure time to maximal recanalization of 49.5 minutes ± 13.0. Symptomatic intracerebral hemorrhage occurred in 6% of patients. The median mRS score at 90 days was 1, and 60% of patients had a good outcome (ie, mRS score 0–2). The overall 3-month mortality rate was 14%.ConclusionsCombined revascularization with the Solitaire stent during IVT appears to be safe and effective in the treatment of acute IAO.     

Outcomes of Stroke Thrombectomy Performed by Interventional Radiologists versus Neurointerventional Physicians

PurposeTo test the hypothesis that interventional radiologists (IRs) and neurointerventional (NI) physicians have similar outcomes of endovascular stroke thrombectomy (EVT), which could be used to improve the availability of thrombectomy.Materials and MethodsEight hospitals providing EVT performed by IRs and NI physicians at the same institution submitted sequential retrospective data limited to the era of modern devices. Good clinical outcomes (a 90-day modified Rankin score [mRS] of 0–2) and technically successful revascularization (a modified thrombolysis in cerebral infarction score of ≥2b) were compared between the specialties after adjusting for treating hospital, patient age, stroke severity, Alberta stroke program early computed tomography score, time from symptom onset to door, and clot location. Propensity score matching was used to compare the outcomes. A total of 1,009 patients were evaluated (622 treated by IRs and 387 treated by NI physicians).ResultsThe median time from stroke onset to puncture was 245 versus 253 minutes (P = .49), the technically successful revascularization rate was 81.8% versus 82.4% (P = .81), and the good clinical outcome rate was 45.5% versus 50.1% (P = .16). After adjusting, the physician specialty was not a significant predictor of good clinical outcomes (odds ratio, 1.028; 95% confidence interval, 0.760–1.390; P = .86). After matching, an mRS of 0–2 was present in 47.7% of IR treated patients and 51.1% of NI treated patients (P = .366).ConclusionsThere were no significant differences in the successful revascularization rate and good clinical outcomes between IRs and NI physicians. The outcomes of EVT performed by IRs were similar to those of EVT performed by NI physicians, as determined using previously published trials and registries. This may be useful for addressing coverage and access to stroke interventions.     

Endovascular Procedures versus Intravenous Thrombolysis in Stroke with Tandem Occlusion of the Anterior Circulation

PurposeStroke with tandem occlusion within the anterior circulation presents a lower probability of recanalization and good clinical outcome after intravenous (IV) thrombolysis than stroke with single occlusion. The present study describes the impact of endovascular procedures (EPs) compared with IV thrombolysis alone on recanalization and clinical outcome.Materials and MethodsThirty patients with symptom onset less than 4.5 hours and tandem occlusion within the anterior circulation were analyzed retrospectively. Recanalization was assessed per Thrombolysis In Cerebral Infarction (TICI) classification on computed tomography, magnetic resonance imaging, or digital subtraction angiography within 24 hours. Infarct size was detected on follow-up imaging as a dichotomized variable, ie, more than one third of the territory of the middle cerebral artery. Clinical outcomes were major neurologic improvement, independent outcome (90-d modified Rankin Scale [mRS] score), symptomatic intracerebral hemorrhage (sICH; per European Cooperative Acute Stroke Study criteria), and death within 7 days.ResultsPatients treated with EPs (n = 14) were significantly younger and had a history of arterial hypertension more frequently than patients treated with IV thrombolysis alone (n = 16). Recanalization (ie, TICI score 2b/3; EP, 64%; IV, 19%; P = .01), major neurologic improvement (EP, 64%; IV, 19%; P = .01), and independent outcome (mRS score ≤ 2; EP, 54% IV, 13%; P = .02) occurred more often in the EP group, whereas infarct sizes greater than one third of the MCA territory (EP, 43%; IV, 81%; P = .03) were observed less often. Rates of sICH (P = .12) and death within 7 days (P = .74) did not differ significantly.ConclusionsHigher recanalization rate, smaller infarct volume, and better clinical outcome in the EP group should encourage researchers to include this subgroup of patients in prospective randomized trials comparing IV thrombolysis versus EP in stroke.     

Contribution and Additional Impact of Imaging to the SPAN-100 Score

BACKGROUND AND PURPOSE:Stroke Prognostication by Using Age and NIHSS score (SPAN-100 index) facilitates stroke outcomes. We assessed imaging markers associated with the SPAN-100 index and their additional impact on outcome determination.MATERIALS AND METHODS:Of 273 consecutive patients with acute ischemic stroke (<4.5 hours), 55 were characterized as SPAN-100-positive (age +NIHSS score ≥ 100). A comprehensive imaging review evaluated differences, using the presence of the hyperattenuated vessel sign, ASPECTS, clot burden score, collateral score, CBV, CBF, and MTT. The primary outcome assessed was favorable outcome (mRS ≤ 2). Secondary outcomes included recanalization, lack of neurologic improvement, and hemorrhagic transformation. Uni- and multivariate analyses assessed factors associated with favorable outcome. Area under the curve evaluated predictors of favorable clinical outcome.RESULTS:Compared with the SPAN-100-negative group, the SPAN-100-positive group (55/273; 20%) demonstrated larger CBVs (<0.001), poorer collaterals (P < .001), and increased hemorrhagic transformation rates (56.0% versus 36%, P = .02) despite earlier time to rtPA (P = .03). Favorable outcome was less common among patients with SPAN-100-positive compared with SPAN-100-negative (10.9% versus 42.2%; P < .001). Multivariate regression revealed poorer outcome for SPAN-100-positive (OR = 0.17; 95% CI, 0.06–0.38; P = .001), clot burden score (OR = 1.14; 95% CI, 1.05–1.25; P < .001), and CBV (OR = 0.58; 95% CI, 0.46–0.72; P = .001). The addition of the clot burden score and CBV improved the predictive value of SPAN-100 alone for favorable outcome from 60% to 68% and 74%, respectively.CONCLUSIONS:SPAN-100-positivity predicts a lower likelihood of favorable outcome and increased hemorrhagic transformation. CBV and clot burden score contribute to poorer outcomes among high-risk patients and improve stroke-outcome prediction.

Several scores have been designed to prognosticate clinical outcomes in acute ischemic stroke and assess potential risks of intravenous thrombolysis.¹ Age and stroke severity measured by the National Institutes of Health Stroke Scale are among major independent prognostic factors for determining stroke outcome.^2,3 Stroke Prognostication Using Age and NIHSS (SPAN-100) was conceived by combining age in years and stroke severity measured by the NIHSS⁴ and applying the combination to predict clinical outcome and risk of intracerebral hemorrhage. With individuals older than 80 years of age constituting a significant proportion of hospitalized patients with acute ischemic stroke, the relevance of the SPAN-100 is self-evident.⁵ Moreover, the elderly also have a higher risk of fatality and longer hospitalization, necessitating the consideration of the benefit-harm ratio preceding rtPA therapy. More interestingly, most stroke predictive scores use either clinical or imaging components, and though several exist, their utility in clinical practice is somewhat restricted.¹ Multimodal imaging-selection strategies are evolving into a cornerstone for stroke management to best define target groups with salvageable tissue at risk.^6–9 Apart from excluding hemorrhage and early ischemic changes, the presence and extent of ischemic core, intravascular clot burden, and extent of collaterals are critical elements assessed by imaging, dictating management and outcome in patients with stroke.¹⁰The simplicity of SPAN-100, using readily accessible information including age and NIHSS, makes it attractive for practical use. Furthermore, imaging features accompanying SPAN-100-positivity provide insight into pathophysiologic characteristics of patients evaluated with SPAN-100. We sought to externally validate SPAN-100, document multimodal CT parameters associated with SPAN-100 status, and assess their interaction with SPAN-100 and clinical outcome.     

Conscious Sedation versus General Anesthesia during Endovascular Acute Ischemic Stroke Treatment: A Systematic Review and Meta-Analysis

BACKGROUND AND PURPOSE:A number of studies have suggested that anesthesia type (conscious sedation versus general anesthesia) during intra-arterial treatment for acute ischemic stroke has implications for patient outcomes. We performed a systematic review and meta-analysis of studies comparing the clinical and angiographic outcomes of the 2 anesthesia types.MATERIALS AND METHODS:In March 2014, we conducted a computerized search of MEDLINE and EMBASE for reports on anesthesia and endovascular treatment of acute ischemic stroke. Using random-effects meta-analysis, we evaluated the following outcomes: recanalization rate, good functional outcome (mRS ≤ 2), asymptomatic and symptomatic intracranial hemorrhage, death, vascular complications, respiratory complications, procedure time, time to groin, and time from symptom onset to recanalization.RESULTS:Nine studies enrolling 1956 patients (814 with general anesthesia and 1142 with conscious sedation) were included. Compared with patients treated by using conscious sedation during stroke intervention, patients undergoing general anesthesia had higher odds of death (OR = 2.59; 95% CI, 1.87–3.58) and respiratory complications (OR = 2.09; 95% CI, 1.36–3.23) and lower odds of good functional outcome (OR = 0.43; 95% CI, 0.35–0.53) and successful angiographic outcome (OR = 0.54; 95% CI, 0.37–0.80). No difference in procedure time (P = .28) was seen between the groups. Preintervention NIHSS scores were available from 6 studies; in those, patients receiving general anesthesia had a higher average NIHSS score.CONCLUSIONS:Patients with acute ischemic stroke undergoing intra-arterial therapy may have worse outcomes with general anesthesia compared with conscious sedation. However, the difference in stroke severity at the onset may confound the comparison in the available studies; thus, a randomized trial is necessary to confirm this association.

Intra-arterial recanalization for acute ischemic stroke is commonly used in patients with large-vessel occlusion.¹ Timely recanalization of the occluded vessel with either IV-tPA or intra-arterial therapy is essential in preventing neuronal death and improving patient outcome.² A number of factors affect patient outcomes following endovascular recanalization, possibly including choice of anesthetic agent during the procedure. Moderate conscious sedation and general anesthesia with intubation are the 2 most commonly used anesthesia techniques for patients with acute ischemic stroke undergoing endovascular recanalization.³ General anesthesia is often the preferred method due to the perceptions of improved procedural safety and efficacy.³ However, conscious sedation and local anesthesia allow operators to monitor neurologic status during the procedure and avoid delays in procedure initiation.⁴ Furthermore, conscious sedation may be associated with improved hemodynamic stability compared with general anesthesia. Due to the continuing debate regarding anesthesia choices during intra-arterial treatment of acute ischemic stroke, we performed a meta-analysis of studies comparing outcomes of patients with stroke receiving general anesthesia and conscious sedation during the procedures.^5,6     

Mechanical Thrombectomy in Patients with Acute Ischemic Stroke and Lower NIHSS Scores: Recanalization Rates,Periprocedural Complications,and Clinical Outcome

BACKGROUND AND PURPOSE:Mechanical thrombectomy, in addition to intravenous thrombolysis, has become standard in acute ischemic stroke treatment in patients with large-vessel occlusion in the anterior circulation. However, previous randomized controlled stroke trials were not focused on patients with mild-to-moderate symptoms. Thus, there are limited data for patient selection, prediction of clinical outcome, and occurrence of complications in this patient population. The purpose of this analysis was to assess clinical and interventional data in patients treated with mechanical thrombectomy in case of ischemic stroke with mild-to-moderate symptoms.MATERIALS AND METHODS:We performed a retrospective analysis of a prospectively collected stroke data base. Inclusion criteria were anterior circulation ischemic stroke treated with mechanical thrombectomy at our institution between September 2010 and October 2015 with an NIHSS score of ≤8.RESULTS:Of 484 patients, we identified 33 (6.8%) with the following characteristics: median NIHSS = 5 (interquartile range, 4–7), median onset-to-groin puncture time = 320 minutes (interquartile range, 237–528 minutes). Recanalization (TICI = 2b–3) was achieved in 26 (78.7%) patients. Two cases of symptomatic intracranial hemorrhage were observed. Favorable (mRS 0–2) and moderate (mRS 0–3) clinical outcome at 90 days was achieved in 21 (63.6%) and 30 (90.9%) patients, respectively.CONCLUSIONS:The clinical outcome of patients undergoing mechanical thrombectomy for acute ischemic stroke with mild stroke due to large-vessel occlusion appears to be predominately favorable, even in a prolonged time window. However, although infrequent, angiographic complications could impair clinical outcome. Future randomized controlled trials should assess the benefit compared with the best medical treatment.

In several randomized multicenter stroke trials, mechanical thrombectomy has proved to be an effective treatment for large intracranial vessel occlusion in patients with acute ischemic stroke in the anterior circulation.^1–5 With the exception of the Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands (MR CLEAN) trial⁴ and Extending the Time for Thrombolysis in Emergency Neurological Deficits–Intra-Arterial (EXTEND-IA),¹ all of those stroke trials did not include patients with minor-to-moderate stroke symptoms but focused on patients with a moderate or severe stroke with a score of at least 6–8 or higher on the National Institutes of Health Stroke Scale. Consequently, the median NIHSS score for patients who underwent mechanical thrombectomy was about 15–17 in all trials; including the MR CLEAN und EXTEND-IA trials.Large intracranial vessel occlusions are not necessarily associated with a high baseline NIHSS score and could be missed in patients with low NIHSS scores.⁶ In a large single-center cohort, 72% of the patients presenting with mild stroke symptoms did not undergo advanced stroke imaging (eg, CT angiography or CT perfusion) before intravenous thrombolysis. However, visualization of a possible proximal occlusion is essential for further treatment decisions. If thrombus length exceeds 8 mm, intravenous thrombolysis has almost no potential to recanalize the occluded vessel.^7,8 The chance for a good clinical outcome (mRS 0–2) is only 7.7% in such cases.⁷ Furthermore, despite intravenous thrombolysis, mortality is 1.3%, and 30.3% of the patients who presented with mild initial stroke symptoms could not ambulate independently at discharge.⁹Even though the complication rate in mechanical thrombectomy is low, the clinical benefit for the patient has to outperform the cost and potential risks. Here, we assessed the outcome of patients with acute ischemic minor-to-moderate stroke who underwent mechanical thrombectomy at our institution. We present data on the location of occlusions, thrombus length, collateral status, recanalization rates, periprocedural complications, and clinical outcome.     

Do Outcomes between Women and Men Differ after Endovascular Thrombectomy? A Meta-analysis

BACKGROUND:Research on the presence of sex-based differences in the outcomes of patients undergoing endovascular thrombectomy for acute ischemic stroke has reached differing conclusions.PURPOSE:This review aimed to determine whether sex influences the outcome of patients with large-vessel occlusion stroke undergoing endovascular thrombectomy.STUDY SELECTION:We performed a systematic review and meta-analysis of endovascular thrombectomy studies with either stratified cohort outcomes according to sex (females versus males) or effect size reported for the consequence of sex versus outcomes. We included 33 articles with 7335 patients.DATA ANALYSIS:We pooled ORs for the 90-day mRS score, 90-day mortality, symptomatic intracranial hemorrhage, and recanalization.DATA SYNTHESIS:Pooled 90-day good outcomes (mRS ≤ 2) were better for men than women (OR = 1.29; 95% CI, 1.09–1.53; P = <.001, I² = 56.95%). The odds of the other outcomes, recanalization (OR = 0.94; 95% CI, 0.77–1.15; P = .38, I² = 0%), 90-day mortality (OR = 1.11; 95% CI, 0.89–1.38; P = .093, I² = 0%), and symptomatic intracranial hemorrhage (OR = 1.40; 95% CI, 0.99–1.99; P = .069, I² = 0%) were comparable between men and women.LIMITATIONS:Moderate heterogeneity was found. Most studies included were retrospective in nature. In addition, the randomized trials included were not specifically designed to compare outcomes between sexes.CONCLUSIONS:Women undergoing endovascular thrombectomy for large-vessel occlusion have inferior 90-day clinical outcomes. Sex-specific outcomes should be investigated further in future trials as well as pathophysiologic studies.

Differences in the treatment and outcomes between women and men with cardiovascular disease are well-documented in the literature. Women undergoing percutaneous coronary interventions have higher hospital mortality rates and complications compared with men.¹ For stroke, men had a higher incidence, but female patients with stroke were more severely ill.² A large series spanning 10 years found that women were less likely to receive IV recombinant tissue plasminogen activator (rtPA) and were also less likely to be enrolled in a clinical trial.³ More recently, however, a review suggested that the disparity between women and men in the rate of IV rtPA administration was no longer apparent in more modern cohorts.⁴The advent of endovascular thrombectomy (EVT) ushered in a new era in the treatment of large-vessel ischemic stroke. Sex-specific outcome analysis of the Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands (MR CLEAN), a randomized controlled trial (RCT) that demonstrated the superiority of endovascular thrombectomy over best medical management, showed that there were no statistically significant treatment effects of EVT for women in terms of 90-day functional outcomes.⁵ On the other hand, a meta-analysis of all the landmark trials for EVT did not show any differences between women and men in terms of outcomes.⁶ However, the latest evidence on the subject comes from the largest real-world cohort of 2399 patients, which shows that women were less likely to receive EVT and be functionally independent at 90 days.⁷ Our systematic review primarily aimed to determine whether sex influences the 90-day clinical outcomes of patients with large-vessel ischemic stroke undergoing EVT. We also examined symptomatic intracranial hemorrhage (sICH), 90-day mortality, and recanalization rate.     

Efficacy and safety of an early Solitaire stent retrieval technique for acute ischemic stroke

Purpose

The aim of this study was to retrospectively evaluate the efficacy and safety of early pull-back of a Solitaire stent as a thrombectomy device in patients with acute ischemic stroke.

Methods

The study group comprised 23 consecutive cases presenting with acute ischemic stroke who were treated with intra-arterial therapy using the Solitaire device as a first-line endovascular procedure. The stent was deployed to cover the thrombus and then left in place for 1–2 min. Immediate angiographic results are presented. Neurologic status was assessed according to the NIH Stroke Scale score (NIHSS) and the modified Rankin Scale (mRS) score.

Results

Successful recanalization (TICI grade ≥2b) was achieved in 21 of the 23 (91.3 %) treated vessels, and 6 of the patients showed immediate flow restoration after the deployment of the first stent. The mean number of passes for maximal recanalization was 1.96. There were no symptomatic procedure-related complications. Of the cases, 34.8 % improved by >10 points on the NIHSS at discharge; 30.4 % of cases revealed good functional outcome (mRS score 0–2) at 90 days.

Conclusions

The early retrieval technique with the Solitaire stent appears to be a safe and effective method in patients with acute ischemic stroke.     

Radiation Segmentectomy for the Treatment of Solitary Hepatocellular Carcinoma: Outcomes Compared with Those of Surgical Resection

PurposeTo investigate the outcomes of radiation segmentectomy (RS) versus standard-of-care surgical resection (SR).Materials and MethodsA multisite, retrospective analysis of treatment-naïve patients who underwent either RS or SR was performed. The inclusion criteria were solitary hepatocellular carcinoma ≤8 cm in size, Eastern Cooperative Oncology Cohort performance status of 0–1, and absence of macrovascular invasion or extrahepatic disease. Target tumor and overall progression, time to progression (TTP), and overall survival rates were assessed. Outcomes were censored for liver transplantation.ResultsA total of 123 patients were included (RS, 57; SR, 66). Tumor size, Child-Pugh class, albumin-bilirubin score, platelet count, and fibrosis stage were significantly different between cohorts (P ≤ .01). Major adverse events (AEs), defined as grade ≥3 per the Clavien-Dindo classification, occurred in 0 patients in the RS cohort vs 13 (20%) patients in the SR cohort (P < .001). Target tumor progression occurred in 3 (5%) patients who underwent RS and 5 (8%) patients who underwent SR. Overall progression occurred in 19 (33%) patients who underwent RS and 21 (32%) patients who underwent SR. The median overall TTP was 21.9 and 29.4 months after RS and SR, respectively (95% confidence interval [CI], 15.5–28.2 and 18.5–40.3, respectively; P = .03). Overall TTP subgroup analyses showed no difference between treatment cohorts with fibrosis stages 3–4 (P = .26) and a platelet count of <150 × 10⁹/L (P = .29). The overall progression hazard ratio for RS versus SR was not significant per the multivariate Cox regression analysis (1.16; 95% CI, 0.51–2.63; P = .71). The median overall survival was not reached for either of the cohorts. Propensity scores were calculated but were too dissimilar for analysis.ConclusionsRS and SR were performed in different patient populations, which limits comparison. RS approached SR outcomes, with a lower incidence of major AEs, in patients who were not eligible for hepatectomy.     

Relationship of Thrombus Length to Number of Stent Retrievals,Revascularization, and Outcomes in Acute Ischemic Stroke

PurposeTo study the relationship between intracranial thrombus length and number of stent retrievals, revascularization rates, and functional outcomes in stroke.Materials and MethodsRetrospective data were collected from consecutive cases of stroke treated with endovascular procedures at a single institution from April 2012–September 2013. Thrombus length was measured in the anterior cerebral circulation. Demographic and clinical details; involved vessels; and procedural details, including the number of devices used and number of retrievals used for each device, were recorded. Revascularization rates and 90-day functional outcomes were recorded.ResultsData regarding the length of thrombus in the anterior cerebral circulation were available for 28 patients. There was no significant association between thrombus length and number of stent retrievals (P = .3780), final thrombolysis in cerebral infarction (TICI) score (P = .4835), or 90-day modified Rankin Scale score (P = .4146). There was a significant difference (P = .0280) between number of retrievals and final TICI score, with lower number of retrieval passes corresponding to higher final TICI scores.ConclusionsThe data suggest no relationship between thrombus length and number of stent retrievals, final TICI score, or functional neurologic outcomes at 90 days in stent retrieval thrombectomy for acute ischemic stroke. These results do not support a predictive value for thrombus length quantification in the evaluation of stroke.     

Body Temperature Modulates Infarction Growth following Endovascular Reperfusion

BACKGROUND AND PURPOSE:The neuronal substrate is highly sensitive to temperature elevation; however, its impact on the fate of the ischemic penumbra has not been established. We analyzed interactions between temperature and penumbral expansion among successfully reperfused patients with acute ischemic stroke, hypothesizing infarction growth and worse outcomes among patients with fever who achieve full reperfusion.MATERIALS AND METHODS:Data from 129 successfully reperfused (modified TICI 2b/3) patients (mean age, 65 ± 15 years) presenting within 12 hours of onset were examined from a prospectively collected acute ischemic stroke registry. CT perfusion was analyzed to produce infarct core, hypoperfusion, and penumbral mismatch volumes. Final DWI infarction volumes were measured, and relative infarction growth was computed. Systemic temperatures were recorded throughout hospitalization. Correlational and logistic regression analyses assessed the associations between fever (>37.5°C) and both relative infarction growth and favorable clinical outcome (90-day mRS of ≤2), corrected for NIHSS score, reperfusion times, and age. An optimized model for outcome prediction was computed by using the Akaike Information Criterion.RESULTS:The median presentation NIHSS score was 18 (interquartile range, 14–22). Median (interquartile range) CTP-derived volumes were: core = 9.6 mL (1.5–25.3 mL); hypoperfusion = 133 mL (84.2–204 mL); and final infarct volume = 9.6 mL (8.3–45.2 mL). Highly significant correlations were observed between temperature of >37.5°C and relative infarction growth (Kendall τ correlation coefficient = 0.24, P = .002). Odds ratios for favorable clinical outcome suggested a trend toward significance for fever in predicting a 90-day mRS of ≤2 (OR = 0.31, P = .05). The optimized predictive model for favorable outcomes included age, NIHSS score, procedure time to reperfusion, and fever. Likelihood ratios confirmed the superiority of fever inclusion (P < .05). Baseline temperature, range, and maximum temperature did not meet statistical significance.CONCLUSIONS:These findings suggest that imaging and clinical outcomes may be affected by systemic temperature elevations, promoting infarction growth despite reperfusion.

The exquisite temperature sensitivity of the neuronal substrate has been detailed extensively since initial reports in canine models in the early 20th century.¹ The development of pyrexia following acute ischemic stroke (AIS) has been well-documented and has been tied to stroke severity, infarct size, and poor functional outcomes, as well as to both short-term and long-term mortality.^2–6The untoward impact of even small brain temperature elevations during ischemic injury is well-described, with histopathologic evidence of irreversible ischemic injury varying substantially with minor temperature changes, and even across physiologic ranges.⁷ It remains unclear, however, whether temperature elevation is associated with poor outcome as a causal factor driving stroke severity and penumbral expansion or as an epiphenomenon to inherently severe or extensive ischemic injury.The goals of this study were to analyze the impact of temperature elevation on the fate of at-risk tissues as derived from the penumbra paradigm of cerebrovascular ischemia by using CTP. We studied the interaction of systemic temperature fluctuations with expansion of infarcted tissues in a cohort of successfully reperfused patients with AIS, hypothesizing greater relative infarction growth as a function of temperature elevation in the early aftermath of AIS.     

Clinical and imaging outcomes after stroke with normal angiograms

BACKGROUND AND PURPOSE: Information about the prognosis of patients with acute ischemic stroke and normal angiography is limited. We report clinical and imaging outcomes of patients seen within 6 hours of symptom onset who were considered candidates for thrombolysis. METHODS: Between November 1994 and December 1999, patients with stroke onset of less than 6 hours who were thrombolytic candidates underwent cerebral angiography. Patients with normal angiograms (defined as no sign of occlusive disease in the head or neck in the symptomatic artery) were included. Admission National Institutes of Health Stroke Scale (NIHSS) scores and discharge modified Rankin scores (mRS) were obtained. CT or MR images were obtained 24 hours or longer after symptom onset. Good outcome was defined as an mRS score < or =2. For analysis, follow-up CT or MR imaging findings were classified as showing cortical infarct, subcortical infarct > or =1.5 cm, subcortical infarct < or =1.5 cm, or no new infarct. The mechanism of the normal angiogram was assumed on the basis of these results. RESULTS: Twenty-one patients with stroke had normal angiograms. About 43% (9/21) of the patients had a favorable hospital discharge clinical outcome, and an additional 33% (7/21) had favorable clinical outcomes at subsequent follow-up. New infarct on follow-up imaging was seen in 71% (15/21). Discharge mRS scores were not correlated with admission NIHSS scores or the mechanism of the normal angiogram. CONCLUSION: Approximately 76% of acute stroke patients with normal angiograms have a favorable clinical outcome, and 71% have associated new infarctions. Given these outcomes, further study is needed before recommendations regarding thrombolytic treatment can be made in this population.     

Posterior Circulation Endovascular Thrombectomy for Large-Vessel Occlusion: Predictors of Favorable Clinical Outcome and Analysis of First-Pass Effect

BACKGROUND AND PURPOSE:Successful vessel recanalization in posterior circulation large-vessel occlusion is considered crucial, though the evidence of clinical usefulness, compared with the anterior circulation, is not still determined. The aim of this study was to evaluate predictors of favorable clinical outcome and to analyze the effect of first-pass thrombectomy.MATERIALS AND METHODS:A retrospective, multicenter, observational study was conducted in 10 high-volume stroke centers in Europe, including the period from January 2016 to July 2019. Only patients with an acute basilar artery occlusion or a single, dominant vertebral artery occlusion (“functional” basilar artery occlusion) who had a 3-month mRS were included. Clinical, procedural, and radiologic data were evaluated, and the association between these parameters and both the functional outcome and the first-pass effect was assessed.RESULTS:A total of 191 patients were included. A lower baseline NIHSS score (adjusted OR, 0.77; 95% CI, 0.61–0.96; P = .025) and higher baseline MR imaging posterior circulation ASPECTS (adjusted OR, 3.01; 95% CI, 1.03–8.76; P = .043) were predictors of better outcomes. The use of large-bore catheters (adjusted OR, 2.25; 95% CI, 1.08–4.67; P = .030) was a positive predictor of successful reperfusion at first-pass, while the use of a combined technique was a negative predictor (adjusted OR, 0.26; 95% CI, 0.09–0.76; P = .014).CONCLUSIONS:The analysis of our retrospective series demonstrates that a lower baseline NIHSS score and a higher MR imaging posterior circulation ASPECTS were predictors of good clinical outcome. The use of large-bore catheters was a positive predictor of first-pass modified TICI 2b/3; the use of a combined technique was a negative predictor.

Posterior circulation stroke accounts for about 20% of all ischemic stroke cases.^1,2 The etiology is variable (thromboembolic, atherosclerosis, arterial dissection, perforating vessels disease, and so forth), affecting different vascular territories; rarely, this type of stroke is due to a large-vessel occlusion of the posterior circulation (pc-LVO), representing about 1% of all acute ischemic strokes,^3,4 Acute pc-LVO carries a high risk of disabling stroke or death. In this context, designing a randomized controlled trial is challenging, and even appropriate patient selection is problematic. Successful vessel recanalization is considered crucial for survival or for improving functional outcome,^5,6 though the evidence of the clinical usefulness of endovascular treatment in pc-LVO compared with anterior circulation LVO is still not determined due to a lack of randomized controlled trial data.In this setting, a recent study supports the safety and efficacy of endovascular treatment for patients with acute ischemic stroke caused by basilar artery occlusion (BAO) who could be treated within 24 hours of the estimated occlusion time.⁷The aims of our study included the evaluation of the effectiveness of the endovascular treatment for acute BAO or single, dominant vertebral artery occlusion (“functional” BAO), the analysis of predicting factors of favorable outcome, and of first-pass effect.     

Impact of Age and Baseline NIHSS Scores on Clinical Outcomes in the Mechanical Thrombectomy Using Solitaire FR in Acute Ischemic Stroke Study

BACKGROUND AND PURPOSE:Age and stroke severity are inversely correlated with the odds of favorable outcome after ischemic stroke. A previously proposed score for Stroke Prognostication Using Age and NIHSS Stroke Scale (SPAN) indicated that SPAN-100-positive patients (ie, age + NIHSS score = 100 or more) do not benefit from IV-tPA. If this finding holds true for endovascular therapy, this score can impact patient selection for such interventions. This study investigated whether a score combining age and NIHSS score can improve patients'' selection for endovascular stroke therapy.MATERIALS AND METHODS:The SPAN index was calculated for patients in the prospective Solitaire FR Thrombectomy for Acute Revascularization study: an international single-arm multicenter cohort for anterior circulation stroke treatment by using the Solitaire FR. The proportion with favorable outcome (90-day mRS score ≤2) was compared between SPAN-100-positive versus-negative patients.RESULTS:Of the 202 patients enrolled, 196 had baseline NIHSS scores. Fifteen (7.7%) patients were SPAN-100-positive. There was no difference in the rate of successful reperfusion (Thrombolysis In Cerebral Infarction 2b or 3) between SPAN-100-positive versus -negative groups (93.3% versus 82.8%, respectively; P = .3). Stroke SPAN-100-positive patients had a significantly lower proportion of favorable clinical outcomes (26.7% versus 60.8% in SPAN-100-negative, P = .01). In a multivariable analysis, SPAN-100-positive status was associated with lower odds of favorable outcome (OR, 0.3; 95% CI_, 0.1–0.9; P = .04). A higher baseline Alberta Stroke Program Early CT Score and a short onset to revascularization time also predicted favorable outcome in the multivariable analysis.CONCLUSIONS:A significantly lower proportion of patients with a positive SPAN-100 achieved favorable outcome in this cohort. SPAN-100 was an independent predictor of favorable outcome after adjusting for time to treatment and the extent of preintervention tissue damage according to the Alberta Stroke Program Early CT Score.

Stroke-related disability remains high at nearly 2 decades since the introduction of IV-tPA as an acute ischemic stroke therapy.¹ Three recent large randomized trials failed to demonstrate the efficacy of endovascular therapies in improving the 90-day functional outcomes over IV-tPA alone.^2–4 These trials are criticized for time delays in achieving reperfusion and for the use of dated devices in most patients. Stent retrievers have proved efficacy over the Merci retriever (Concentric Medical, Mountain View, California),^5,6 but they were used in <1% of patients in the recent neutral trials. Therefore, at least 4 multicenter randomized trials of acute stroke endovascular therapy by using stent retrievers are currently recruiting, and other trials are launching soon.The importance of patient selection for endovascular therapy of acute ischemic stroke cannot be overemphasized. While controversy exists regarding the optimal imaging technique for patient selection for endovascular therapy, there are proved and readily-available clinical indicators. Among the factors associated with poor functional recovery, age and NIHSS score are most relevant.⁷ This finding led to the derivation of the Stroke Prognostication Using Age and NIHSS Stroke Scale (SPAN) index by adding the patient age in years plus the baseline NIHSS score. Investigators reported that patients in the National Institute of Neurological Disorders and Stroke trial with a score of ≥100 (SPAN-100) did not benefit from IV-tPA therapy, with a higher rate of symptomatic intracranial hemorrhage and poor functional outcome compared with SPAN-100-negative patients.⁸ However, these findings do not take into account the rate of successful recanalization that has been consistently shown to be one of the strongest predictors of favorable stroke outcome.⁹ The National Institute of Neurological Disorders and Stroke trial,¹⁰ conducted between 1991 and 1994, does not reflect contemporary stroke care; this feature limits its generalizability.If the SPAN-100 index can identify patients who do not benefit from endovascular therapy, this simple and readily available index will have implications for patient eligibility for these interventions. We assessed the impact of the SPAN-100 index in the large multicenter prospective study for mechanical thrombectomy in acute ischemic stroke, Solitaire FR Thrombectomy for Acute Revascularization (STAR).¹¹