Recanalization In Acute Ischemic Stroke Research Articles

Abstract WMP17: Computerized Tomography Perfusion to Characterize Lack of Clinical Improvement After Recanalization in Acute Ischemic Stroke

A significant proportion of patients with acute ischemic stroke (AIS) treated with endovascular thrombectomy (EVT) present poor functional outcome despite recanalization. We aim to investigate computed tomography perfusion (CTP) patterns after EVT and their association with outcome Methods: Prospective study of anterior large vessel occlusion AIS patients who achieved complete recanalization (defined as modified Thrombolysis in Cerebral Ischemia (TICI) 2b - 3) after EVT. CTP was performed within 30 minutes post-EVT recanalization (POST-CTP): hypoperfusion was defined as volume of time to maximal arrival of contrast (Tmax) delay ≥6 seconds in the affected territory. Hyperperfusion was defined as visual increase in cerebral blood flow (CBF) and volume (CBV) with advanced Tmax compared with the unaffected hemisphere. Dramatic clinical recovery (DCR) was defined as a decrease of ≥8 points in NIHSS score at 24h or NIHSS≤2 and good functional outcome by mRS ≤2 at 3 months. Results: One-hundred and forty-one patients were included. 49 (34.7%) patients did not have any perfusion abnormality on POST-CTP, 60 (42.5%) showed hypoperfusion (median volume Tmax≥6s 17.5cc, IQR 6-45cc) and 32 (22.8%) hyperperfusion. DCR appeared in 56% of patients and good functional outcome in 55.3%. Post-EVT hypoperfusion was related with worse final TICI, and associated worse early clinical evolution, larger final infarct volume (p<0.01 for all) and was an independent predictor of functional outcome (OR 0.98, CI 0.97-0.99, p=0.01). Furthermore, POST-CTP identified patients with delayed improvement: in patients without DCR (n=62, 44%), there was a significant difference in post-EVT hypoperfusion volume according to functional outcome (hypoperfusion volume of 2cc in good outcome vs 11cc in poor outcome, OR 0.97 CI 0.93-0.99, p=0.04), adjusted by confounding factors. Hyperperfusion was not associated with worse outcome (p=0.45) nor symptomatic hemorrhagic transformation (p=0.55). Conclusion: Hypoperfusion volume after EVT is an accurate predictor of functional outcome. In patients without dramatic clinical recovery, hypoperfusion predicts good functional outcome and defines a “stunned-brain” pattern. POST-CTP may help to select EVT patients for additional therapies.

Abstract TP340: The Level of Occludin in Blood as a Potential Biomarker for Blood-Brain Barrier Damage and Predicting Hemorrhage Transformation After Acute Ischemic Stroke

Fear of hemorrhage transformation (HT) has been the primary reason for withholding the effective recanalization therapies (thrombolysis or thrombectomy) from most acute ischemic stroke (AIS) patients. Currently there is no reliable indicator available to predict HT before recanalization. The degradation of tight junction proteins plays a critical role in blood-brain barrier (BBB) disruption in ischemic stroke. We hypothesize that since occludin fragment in peripheral blood is derived from the degradation of occludin on cerebral microvessels, elevated blood occludin level directly reflects BBB disruption and may serve as a biomarker for BBB damage to predict the risk of HT after recanalization. In this study, we determined occludin fragment in the blood of rats, non-human primates and human patients after AIS using ELISA assay, and evaluated its level with BBB damage, HT, and other neurological outcomes. We found that ischemia induced rapid occludin degradation and BBB disruption, while occludin fragment was released into the blood circulation. Cerebral ischemia resulted in a dramatic increase of occludin fragments in rat blood samples after 4-hr ischemia, which was correlated well with occludin loss from ischemic cerebral microvessels. In the blood sample from ischemic rhesus monkeys, occludin level significantly increased after 2h ischemia from baseline, which correlated well with brain infarction shown in MRI images. We further collected the sera of AIS patients as early as they arrived at hospital. Our results indicated that the level of occludin increased in accord with ischemia onset time and neurological dysfunctions. The level of blood occludin in AIS patients with HT was much higher that those without HT. Together, our findings from rats, non-human primates and patients suggest that the level of occludin fragment in blood could serve as a biomarker for HT and neurological outcome following AIS, which could be used to safely guide recanalization for AIS in the clinic.

Associated Factors and Long-Term Prognosis of 24-Hour Worsening of Arterial Patency After Ischemic Stroke.

Background and Purpose- Early arterial recanalization in acute ischemic stroke is strongly associated with better outcomes. However, early worsening of arterial patency was seldom studied. We investigated potential predictors and long-term prognosis of worsening of arterial patency at 24 hours after stroke onset. Methods- Patients from the Acute Stroke Registry and Analysis of Lausanne registry including admission and 24-hour vascular imaging (computed tomography or magnetic resonance angiography) were included. Worsening of arterial patency was defined as a new occlusion and significant stenosis in any extracranial or intracranial artery, comparing 24 hours with admission imaging. Variables associated with worsening of arterial patency were assessed by stepwise multiple logistic regression. The impact of arterial worsening on 3-month outcome was investigated with an adjusted modified Rankin Scale shift analysis. Results- Among 2152 included patients, 1387 (64.5%) received intravenous thrombolysis and endovascular treatment, and 65 (3.0%) experienced 24-hour worsening of arterial patency. In multivariable analysis, history of hypertension seemed protective (adjusted odds ratio [aOR], 0.45; 95% CI, 0.27-0.75) while higher admission National Institutes of Health Stroke Scale (aOR, 1.06; 95% CI, 1.02-1.10), intracranial (aOR, 4.78; 95% CI, 2.03-11.25) and extracranial stenosis (aOR, 3.67; 95% CI, 1.95-6.93), and good collaterals (aOR, 3.71; 95% CI, 1.54-8.95) were independent predictors of worsening of arterial patency. Its occurrence was associated with a major unfavorable shift in the distribution of the modified Rankin Scale at 3 months (aOR, 5.97; 95% CI, 3.64-9.79). Conclusions- Stroke severity and admission vascular imaging findings may help to identify patients at a higher risk of developing worsening of arterial patency at 24 hours. The impact of worsening of arterial patency on long-term outcome warrants better methods to detect and prevent this early complication.

When to Stop

Background and Purpose- Substantial proportion of patients who achieve successful recanalization of acute ischemic stroke due to large vessel occlusion do not achieve good functional outcome. We aim to analyze the effect of number of thrombectomy device passes and degree of the recanalization (by modified Thrombolysis in Cerebral Infarction) on the clinical and functional outcome. Methods- Five hundred forty-two consecutive patients underwent mechanical thrombectomy for large vessel occlusion in the anterior circulation at a single tertiary stroke center. Baseline characteristics, number of passes, recanalization degree, clinical outcome at 24 hours (measured by National Institutes of Health Scale score), and functional outcome (measured by modified Rankin Scale at 90 days) were registered. Multivariate analysis was performed to determine the association of number of passes and degree of recanalization with dramatical clinical recovery (final National Institutes of Health Scale score ≤2 or decrease in 8 or more National Institutes of Health Scale score points in 24 hours) and good functional outcome (modified Rankin Scale score ≤2 at 90 days). Results- Four hundred fifty-nine patients (84%) achieved successful recanalization (modified Thrombolysis in Cerebral Infarction 2B-3), 213 (39%) of them after first device pass. In the multivariate analysis, first-pass recanalization and modified Thrombolysis in Cerebral Infarction 3 were independent predictors of good functional outcome (odds ratio, 2.5; 95% CI, 1.4-4.5; P=0.002 and odds ratio, 2.6 CI; 1.5-4.7; P=0.001, respectively) and dramatical clinical recovery (odds ratio, 1.8; 95% CI, 1.1-3; P=0.032 and odds ratio, 2.9; 95% CI, 1.7-5.1; P<0.001, respectively). Rate of recanalization declined after each pass 39% (213/542), 35% (113/310), 33% (63/190), and 24% (26/154) for passes 1 to 4, respectively and 28% (45/158) for every attempt above 4 passes ( P<0.001). In patients who achieved recanalization, a linear association between number of passes and good functional outcome was observed: 1 pass (58.6%), 2 passes (50.5%), 3 passes (48.4%), 4 passes (38.5%), or 5 or more passes (25.6%; P<0.001) as compared with patients who did not achieve recanalization (16.9%). Conclusions- High number of device passes and less degree of recanalization are associated with worse outcome in patients with acute ischemic stroke secondary to large vessel occlusion. Future studies should investigate the optimal number of passes that should be attempted in patients without substantial recanalization.

Impact of basal ganglia damage after successful endovascular recanalization for acute ischemic stroke involving lenticulostriate arteries.

Regional ischemic vulnerability of the brain reportedly differs between the cortex and basal ganglia and has been poorly assessed in the setting of endovascular mechanical thrombectomy. This study was conducted to determine the fate of an ischemic basal ganglia and its contribution to the clinical outcome after successful endovascular recanalization for acute ischemic stroke with large vessel occlusion involving the lenticulostriate arteries. Clinical and radiological findings were retrospectively analyzed in consecutive patients with acute ischemic stroke characterized by large vessel occlusion involving the lenticulostriate arteries. Mechanical thrombectomy was performed in all patients using a stent retriever. The fate of ischemic basal ganglia based on location (lentiform nucleus, caudate nucleus, and internal capsule) and insular cortex was assessed according to the Alberta Stroke Programme Early CT Score (ASPECTS). Of 170 patients with large intracranial vessel occlusion who achieved successful endovascular recanalization, defined as a thrombolysis in cerebral infarction grade of ≥ 2B, involvement of the lenticulostriate arteries was seen in 55 patients (internal carotid artery, n = 35; proximal middle cerebral artery, n = 20). Preoperative infarction was detected in the lentiform nucleus (66.7%), internal capsule (11.1%), and caudate nucleus (33.3%), all of which showed secondary advancement despite successful recanalization (85.4%, 27.3%, and 54.5%, respectively; p < 0.05). Lenticulostriate arteries with a lateral proximal and/or medial proximal origin significantly affected the development of mature infarction in the lentiform nucleus. Postoperative hemorrhagic transformation was detected in 25 of 55 patients, mostly in the lentiform nucleus. Involvement of insular ribbon infarction was significantly high in patients with hemorrhagic transformation in the basal ganglia. Age, initial National Institutes of Health Stroke Scale (NIHSS) score, initial ASPECTS, postoperative ASPECTS, postoperative infarction in the insular ribbon, and lesions in the middle cerebral artery area (M1-M6) were significantly different between patients with good and poor modified Rankin Scale scores. Interestingly, no differences were detected in postoperative infarction or hemorrhagic transformation in the basal ganglia. Multivariate analysis showed that only age (p = 0.02, OR 0.88) and the initial NIHSS score (p = 0.01, OR 0.86) independently affected favorable clinical outcomes. The basal ganglia are vulnerable and readily develop secondary infarction and hemorrhagic transformation despite successful recanalization. However, this does not have a significant impact on the clinical outcome of acute ischemic stroke with large vessel occlusion involving the lenticulostriate arteries.

Ultrasound Identification of Patients at Increased Risk of Intracranial Hemorrhage After Successful Endovascular Recanalization for Acute Ischemic Stroke

Intracranial hemorrhage (ICH) is the most feared complication of endovascular treatment (EVT) for acute ischemic stroke because of anterior circulation large vessel occlusion (LVO). The purpose of this study was to identify cerebral hemodynamic predictors of ICH and poor outcome in patients with successful recanalization. Serial transcranial color-coded sonography (TCCS) examinations assessed vessel status and cerebral hemodynamics of 226 (mean age, 69.8 ± 12.5 years; 130 men [57.5%]) consecutive patients with acute anterior circulation LVO at 48 hours and 1 week after EVT. Middle cerebral artery peak systolic velocity (PSVMCA) and PSVMCA ratio (recanalized PSVMCA/contralateral PSVMCA) were recorded. Out of 180 successfully recanalized patients (79.6%), 28 patients (15.5%) had ICH. They more often had arterial hypertension (25/28 [89.3%] vs. 106/152 [69.7%], P=0.04), a more severe stroke syndrome (18 [range, 10-23] vs. 16 [range, 5-26], P= 0.01), a worse clinical outcome (90-day modified Rankin Scale [mRS] score 3-5: 16/28 [57.1%] vs. 42/152 [27.6%], P= 0.004), and soon after EVT showed a significantly higher mean PSVMCA ratio (3.4 ± 0.1 vs. 2.4 ± 0.1, P < 0.0001) than patients without ICH, respectively. In multivariate analysis, early PSVMCA ratio was independently associated with postinterventional ICH (odds ratio, 13.379; 95% confidence interval, 2.466-50.372; P<0.01). The patients with ICH (19/28 [67.9%]) who resumed normal PSVMCA values at 1 week after EVT had a better outcome (90-day mRS score 0-2: 8/19 [42.1%] vs. 0/9 [0%], respectively). Early TCCS detection of a high PSVMCA ratio in successfully recanalized stroke patients indicates an increased risk of ICH, whereas cerebral hemodynamics normalization at 1 week in patients with postinterventional ICH predicts a relatively better 3-month outcome.

Abstract WP57: Effect of Single Pass Recanalization in Acute Ischemic Stroke With Large Vessel Occlusion: Sub-Analysis of Rescue-Japan Registry 2

Introduction: In endovascular treatment (EVT) for acute large vessel occlusion (LVO), multiple passes may promote arterial endothelial injury, potentially reducing clinical efficacy and safety. However, data comparing outcome between single and multiple passes are scarce. Methods: In the Recovery by Endovascular Salvage for Cerebral Ultra-acute Embolism (RESCUE)-Japan Registry 2, 2420 patients with acute stroke due to LVO were registered between October 2014 and January 2017. Among them, 1064 patients treated with EVT were analyzed. We classified patients into two groups, a single-pass group and a multiple-pass group, archiving good recanalization (TICI2b-3) in single or multiple passes, and analyzed clinical features and outcomes. Multivariate analyses were performed to determine whether single-pass recanalization was independently associated with improved outcomes and to identify factors associated with needing only a single pass. Results: 592 patients were recanalized by single pass, and 472 patients by multiple passes. Compared with the multiple-pass group, fewer patients in the single-pass group suffered extracranial internal carotid artery occlusion (9.6% vs 14.4%, p=0.014), and more patients suffered M2 occlusion (18.6% vs 14.0%, p=0.045) Onset to recanalization time in the single-pass group was shorter than the multiple-pass group (378.3 minutes vs 397.2 minutes, p=0.00012) Cardiogenic embolic stroke was present in 78.7% and 66.5% of single- and multiple-pass groups (p&lt;0.0001). Modified Rankin scale scores of 0 to 2 at 90 days after onset were observed in 51.5% and 39.0% of patients in the single- and multiple-pass groups (p&lt;0.0001). The adjusted odds ratio (OR) of single pass for a modified Rankin scale score of 0 to 2 at 90 days after onset was 1.59 (95% confidence interval, 1.22-2.06). Intracranial hemorrhage after EVT were observed in 23.3% and 32.6% of patients in the single- and multiple-pass groups (p=0.001). The factors associated with achieving single-pass recanalization was cardiogenic embolic stroke (p=0.00013; OR, 1.75; 95% confidence interval, 1.31-2.33) adjusting for other variables. Conclusion: Achievement of recanalization in a single pass was associated with good clinical outcome.

Strategy to Achieve Faster Recanalization for Acute Ischemic Stroke in a University Hospital with Many Constraints

Strategy to Achieve Faster Recanalization for Acute Ischemic Stroke in a University Hospital with Many Constraints

Reader response: Usefulness of ADAMTS13 to predict response to recanalization therapies in acute ischemic stroke.

We read with interest the innovative study by Bustamante et al.1 that focuses on the prognostic role of ADAMTS13 (a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13) in recanalization of acute ischemic stroke. Beyond limitations already noted by the authors, important issues need to be further discussed.

Diffusion-weighted imaging lesion growth occurs despite recanalization in acute ischemic stroke: Implications for future treatment trials.

A proportion of patients presenting with acute small ischemic strokes have poor functional outcomes, even following rapid recanalization treatment. Infarct growth may occur even after successful recanalization and could represent an appropriate endpoint for future stroke therapy trials. Magnetic resonance diffusion-weighted imaging lesion volumes were obtained at 5 h (initial posttreatment) and 24 h (follow-up) after acute stroke treatment for n = 33 in ischemic stroke patients. Sample sizes per arm (90% power, 30% effect size) for diffusion-weighted imaging lesion growth between initial and 24 h, early change in the National Institutes of Health Stroke Scale between pre- and 24 h, National Institutes of Health Stroke Scale at 24 h, and diffusion-weighted imaging lesion volume at 24 h were estimated to power a placebo-controlled stroke therapy trial. For patients with poor recanalization (modified thrombolysis in cerebral infarction <2 a; modified arterial occlusion lesion = 0-2) (n = 11), the median diffusion-weighted imaging lesion growth was 8.1 (interquartile range: 4.5, 22.4) ml and with good recanalization (modified thrombolysis in cerebral infarction =2 b or 3; modified arterial occlusion lesion = 3) (n = 22), the median diffusion-weighted imaging lesion growth was 10.0 (interquartile range: 6.0, 28.2) ml ( P = 0.749). When considering a 30% effect size, the sample size required per arm to achieve significance in an acute stroke study would be: (1) N = 49 for the diffusion-weighted imaging lesion growth between initial posttreatment and follow-up time points, (2) N = 65 for the change in the National Institutes of Health Stroke Scale between admission and 24 h, (3) N = 259 for the National Institutes of Health Stroke Scale at 24 h, and (4) N = 256 for diffusion-weighted imaging volume at 24 h. Despite best efforts to recanalize the ischemic brain, early diffusion-weighted imaging lesion growth still occurs. Treatment trials in stroke should consider early diffusion-weighted imaging lesion growth as a surrogate outcome measure to significantly reduce sample sizes.

Cerebral Ischemic Reperfusion Injury Following Recanalization of Large Vessel Occlusions.

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

ГЕМОСТАЗИОЛОГИЧЕСКИЕ МАРКЕРЫ ПРОГНОЗИРОВАНИЯ РЕОККЛЮЗИИ ПОСЛЕ ТРОМБОЛИТИЧЕСКОЙ ТЕРАПИИ У ПАЦИЕНТОВ С КАРДИОЭМБОЛИЧЕСКИМ ИНСУЛЬТОМ

Цель работы: определить прогностическую значимость гемостазиологических параметров в развитии реокклюзии после тромболитической терапии у пациентов с кардиоэмболическим инсультом. Материалы и методы. Проанализировано лечение 52 пациентов с кардиоэмболическим типом ишемического инсульта, тяжесть которого по шкале NIHSS составляла 10-17 баллов. Данные пациенты попадали в терапевтическое окно, и согласно национальным рекомендациям им был проведен системный тромболизис. Ретроспективно больные были разделены на 2 группы: с эффективным тромболизисом (n = 36) и с признаками реокклюзии (n = 14). Результаты. Через 3 часа после тромболитической терапии у пациентов, у которых впоследствии развилась реокклюзия, в ответ на тромболитическую терапию наблюдалась мощная активация системы гемостаза, проявляющаяся существенным повышением уровня Д-димера и формированием патологически плотного сгустка на тромбоэластограмме. По данным ROC-анализа выявлена хорошая прогностическая точность в отношении развития реокклюзии со стороны концентрации Д-димера (AUROC = 0,766; точка отсечения – значения Д-димера ≥ 0,75 нг/мл) и отличная прогностическая точность со стороны параметра МА тромбоэластограммы (AUROC = 0,903; точка отсечения – значения МА ≥ 48 мм). Заключение. Для выделения когорты пациентов, которым в связи с высоким риском реокклюзии показано назначение антикогулянтов (антиагрегантов) сразу же после тромболизиса, необходимы дальнейшие исследования. Aim: to determine the prognostic significance of hemostasiological parameters in the development of reocclusion after thrombolytic therapy in patients with cardioembolic stroke. Materials and methods. The treatment of 52 patients with cardioembolic type of ischemic stroke (the severity – 10-17 points according NIHSS scale) was analyzed. These patients received systemic thrombolysis according to national guidelines. Retrospectively patients were divided into 2 groups: with effective thrombolysis (n = 36) and with signs of reocclusion (n = 14). Results. Three hours after thrombolytic therapy in patients with further developed reocclusion powerful hemostasis activation was observed that manifested by a significant increasing of D-dimer level and formation of a pathologically dense clot on thromboelastogram. According to ROC analysis good prognostic accuracy of reocclusion development for D-dimer level (AUROC = 0,766; cut-off point – D-dimer ≥ 0,75ng/ml) and excellent prognostic accuracy for parameter MA of thromboelastogram (AUROC = 0,903; cut-off point – МА ≥ 48 mm) were revealed. Conclusion. Further studies are needed for identification of patients with high risk of reocclusion who are prescribed the appointment of anticoagulants (antiaggregants) immediately after thrombolysis.

Prehospital stroke scales and large vessel occlusion: A systematic review.

Time sensitivity for pharmacological and mechanical arterial recanalization in acute ischemic stroke influences the choice of the reference hospital. The accurate selection and identification of patients with high probability of a large vessel occlusion (LVO) in the prehospital setting improve the rationalization of the transport in the more suitable centers. Aim of this analysis was to determine the diagnostic accuracy of prehospital stroke scales detecting LVO. Studies were searched into MEDLINE, EMBASE, and CINHAL databases between January 1990 and September 2017. Principal measurements of the meta-analysis were the overall accuracy level, sensitivity, and specificity of prehospital stroke scales. Nineteen scoring systems were included in the analysis coming from 13 studies. A total of 9824 patients were considered. Although a higher heterogeneity was observed in the analysis, three scores showed better results in predicting a LVO (the stroke Vision, Aphasia, Neglect assessment, the National Institute of Health Stroke scale and the Los Angeles Motor Scale). We observed significant differences of overall accuracy only for scores including hemineglect as cortical neurological sign (P<.05). This meta-analysis suggests that some prehospital scoring systems including cortical signs showed better accuracy to predict stroke due to LVO. However, the assessment of these signs could be difficult to investigate by paramedics and personnel of Emergency Medical Services, and for this reason, further prospective evaluations are needed.

Abstract WP21: Different View on Clinical Application of Tirofiban After Mechanical Arterial Recanalization in Acute Ischemic Stroke

Tirofiban, an antiplatelet drug and glycoprotein-IIb/IIIa inhibitor, widely used in cardiovascular events, appears to be safe and effective in cerebrovascular stroke. However, its efficacy post-endovascular therapy raised concern due to an association with increased risk of fatal intracerebral hemorrhage (ICH) and poor outcome in ischemic patients (Kellert et al. 2013). The success of 5 randomized clinical trials in stroke therapy in 2015 utilizing new generation endovascular intervention prompted this study of continuous intravenous administration of Tirofiban after thrombectomy with the Solitaire stent, one of the two new devices, in patients with acute ischemic stroke. A consecutive series of patients (n=28) who received Solitaire stent thrombectomy from January 2017 to the present was enrolled. 22 of the 28 patients were eligible for intravenous Tirofiban treatment for 24 h after receiving endovascular therapy. 6 patients were excluded because of no vessel recanalization, vessel recanalization achieved by other devices, or ICH after endovascular therapy. The incidence of symptomatic ICH and death was recorded. The number of thrombectomy attempts and device manipulation time within vessels were measured as potential markers for endothelial damage. The NIH stroke and modified Rankin scales were assessed at 7 days and 3 months, respectively. In all 22 patients who received Tirofiban after endovascular therapy, none had symptomatic ICH nor died from treatment. Successful recanalization rate (TICI≥2b) was achieved in 18 (86.4%) of 22 patients after endovascular therapy. As compared to the study by Kellert et al., the lower average device passages (1.2 vs 2.0) and short device manipulation time (56 vs 104 min) together suggested less endothelial damage. Of our patients, 77.3% showed neurological improvement at 7 days and 59.1% patients had favorable outcomes with a Modified Rankin scale of 0 to 2 at 3 months. These favorable outcomes were similar to those achieved in the 5 positive randomized trials. In conclusion, the continuous application of Tirofiban post-Solitaire stent thrombectomy appears to be safe and effective in acute ischemic stroke. Reduced endothelial damage may play a key role in clinical outcomes with Tirofiban application.

Abstract WMP12: Feasibility of Permanent Stenting With Solitaire Fr as a Rescue Treatment for the Reperfusion of Acute Intracranial Artery Occlusion

Background and Purpose: Solitaire FR can be used not only as a tool for mechanical thrombectomy but also as a detachable permanent stent. Our aim was to assess the feasibility and safety of permanent stenting with Solitaire FR (erv3, Irvine, CA, USA) compared with other self-expanding stents for intracranial artery recanalization for acute ischemic stroke. Materials and Methods: From January 2011 through January 2016, 2,979 patients with acute ischemic stroke were retrospectively selected. Among them, 27 patients who underwent permanent stenting (13 patients with Solitaire FR (Solitaire group) and 14 patients with other self-expanding stents (other stent group)) were enrolled. The post-procedural mTICI grade and angiographic and clinical outcomes at discharge and 3 months were assessed. The safety and efficacy of permanent stenting of Solitaire FR stent placement for acute large arterial occlusion were evaluated. Results: Stent placement was successful in all cases. mTICI 2b-3 reperfusion was noted in 84.6% of Solitaire group and in 78.6% of other stent group. Procedure time was significantly shorter in Solitaire group than other stent group ( P = 0.022). No significant differences were found in mTICI grade, NIHSS score at discharge, mRS at 3 months, and rate of hemorrhagic transformation between the two groups. Acute in-stent thrombosis rate at discharge was significantly lower when glycoprotein IIb/IIIa inhibitor was injected during the procedure ( P = 0.013). Conclusions: Permanent stenting of Solitaire FR compared with other self-expanding stents appears to be feasible and safe as a rescue tool for refractory intra-arterial therapy.

Contrast‐enhanced sonothrombolysis in acute ischemic stroke patients without intracranial large‐vessel occlusion

Contrast-enhanced sonothrombolysis (CEST) leads to a more rapid recanalization in acute ischemic stroke caused by intracranial large-vessel occlusion (LVO). Animal studies have shown that CEST also may be safe and efficient in treating the ischemic microcirculation in the absence of LVO. The exact mechanism behind this treatment effect is not known. We aimed to assess safety and efficacy of CEST in acute ischemic stroke patients included in the Norwegian Sonothrombolysis in Acute Stroke Study (NOR-SASS) without LVO on admission CT angiography (CTA). NOR-SASS was a randomized controlled trial of CEST in ischemic stroke patients treated with intravenous thrombolysis within 4.5hours after stroke onset. Patients were randomized to either CEST or sham CEST. In this study, patients were excluded if they had partial or total occlusion on admission CTA, ultrasound-resistant bone window, had received CEST with incorrect insonation as compared to stroke location on Magnetic resonance imaging (MRI), or were stroke mimics. Of the 183 patients included in NOR-SASS, a total of 83 (45.4%) patients matched the inclusion criteria, of which 40 received CEST and 43 sham CEST. There were no patients with symptomatic intracranial hemorrhage (sICH) in the CEST group. Rates of asymptomatic ICH, microbleeds, and mortality were not increased in the CEST group. Neurological improvement at 24hours and functional outcome at 90days were similar in both groups. CEST is safe in ischemic stroke patients without intracranial LVO. There were no differences in clinical outcomes between the treatment groups.

Can clot density predict recanalization in acute ischemic stroke treated with intravenous tPA?

Stroke has become an absolute emergency that is treated by additional endovascular means or by replacing pharmacological options. Modern neuroradiological techniques such as computed tomography (CT) allow us to examine multiple parameters of the diseased brain. These focused on the parenchyma and hemodynamics for pretherapeutic decisions. However, it has become evident that the clot is the current target for interventional measures. Clot length is established as a marker for recanalization. The dense artery sign is known as an acute CT sign of stroke that is readily visible on acute nonenhanced CT. The rationale behind our study was to study if clot density might represent clot vulnerability or resistance to treatment. We conducted a prospective study of all consecutive stroke patients admitted to our hospital over 1 year, who presented with signs of acute middle cerebral artery stroke within the therapeutic window, and who underwent either intravenous or combined intravenous and intra-arterial thrombolysis. All patients were evaluated with a complete stroke CT protocol, transcranial color-coded duplex sonography monitoring, and clinical evaluation with the National Institutes of Health Stroke Scale (NIHSS) score. We measured clot length using planimetry on unenhanced CT and measured Hounsfield units in the clots on the same images. A total of 31 patients were included in the study (19 men, 12 women, aged 35–90 years). We found that patients with a longer clot on the unenhanced CT had a higher NIHSS score, confirming previous literature. However, we found that patients with a lower clot density recanalized to a more marked degree and had a better clinical outcome. Patients who did not recanalize had a higher clot density (49 Hounsfield units) than those who did recanalize (23 Hounsfield units). Overall, measuring the clot seems to be an important additional parameter to be taken into account. In our study, CT clot density seems to correlate with clinical outcome and recanalization. The higher density seems to represent a higher red blood cell content. This is evidence that clot composition could play a much more important role in acute stroke than thought until now and characterizing it with imaging may help in choosing the adequate treatment modality. Higher density seems to reflect erythrocyte content. Therefore, patients with a longer and denser clot may necessitate direct thrombectomy.

O2-2-6 - Collateral flow detected by arterial spin labelling MR imaging can predict outcome in endovascular recanalization for acute ischemic stroke

O2-2-6 - Collateral flow detected by arterial spin labelling MR imaging can predict outcome in endovascular recanalization for acute ischemic stroke

Abstract TP5: What is “Near Complete” Recanalization? Rethinking TICI 2b in Modern Thrombectomy Era

Background and purpose: The Thrombolysis in Cerebral Infarction (TICI) 2b classification is defined as “near complete” recanalization for acute ischemic stroke. While this category has historically combined with TICI 3 (“complete reperfusion”) as “successful recanalization”, recent studies have suggested that TICI 3 and a proposed intermediate TICI 2c (“near complete reperfusion except for slow flow or distal emboli”) should be distinguished from TICI 2b due to differences in outcomes. In this study, we examined if early neurologic improvement differed significantly between patients with TICI 2b, TICI 2c, and TICI 3 recanalization for emergent large vessel occlusions treated with mechanical thrombectomy (MT). Methods: Retrospective analysis was performed using data from 133 consecutive patients with middle cerebral artery or internal carotid artery occlusions treated with MT from January 2015 to June 2016. Patient angiograms were graded independently and blinded to clinical data by two experienced readers based on original TICI (oTICI), modified TICI (mTICI), and modified TICI with TICI 2c (mTICI 2c) grading scales. Early neurologic improvement was assessed using change in NIHSS by discharge. General linear modeling was used to evaluate difference in NIHSS delta scores between TICI scales with SAS/PROC GLIMMIX. Multiple comparisons were evaluated using Tukey corrections with significance established at the .05 level. Results: Without the TICI 2c category, there was not a significant difference in change in NIHSS observed between TICI 3 and TICI 2b for both the oTICI (delta 1.4, p=0.355) and mTICI scales (delta 2.1, p=0.190). However, when an additional category (TICI 2c) was added, there was a significant difference in change in NIHSS observed between TICI 3 and TICI 2b (delta 3.8, p= 0.026) as well as between TICI 2c and TICI 2b (delta 3.7, p=0.019). Conclusion: Utilizing a TICI recanalization grading system that adds an additional category beyond TICI 2b allows for improved prediction of neurological improvement in patients treated with MT. Higher levels of recanalization are associated with greater neurologic improvement.

Abstract TMP7: Endovascular Stroke Therapy Abrogates Sex-Related Differences in Recanalization in Acute Ischemic Stroke

Background: Ischemic stroke affects women differently than men. Prior studies evaluating recanalization treatment with IV tpA showed that while women are more likely to achieve recanalization, there are strong sex disparities with respect to clinical outcome. We evaluated the effect of endovascular stroke therapy (ET) on recanalization and outcomes in women versus men. Methods: In the combined databases of the SWIFT, STAR, and SWIFT-PRIME trials, we identified patients treated with the Solitaire stent retriever to determine the effects of sex on recanalization and clinical outcome. Results: Among 389 patients treated with ET, mean age was 67±13, 55% were female, and median National Institutes of Health Stroke Scale (NIHSS) score was 17 [8-28]. There were no differences between females vs. males in presentation NIHSS (17 vs. 17, p=0.21), occlusion location (69% vs. 64% M1, p=0.62), or ASPECTS score (9 vs. 8, p=0.24). Rates of successful TICI 2b/3 recanalization were nearly identical (87% vs. 83%, p=0.374). There were no differences in onset to recanalization time (OTR) (277 vs. 306, p=0.46), procedural time (44 vs. 48 minutes, p=0.23), number of stent-retriever passes (1.7 vs. 1.8, p=0.17), rate of PH2 hemorrhage (1.9% vs. 1.1%, p=0.70), or functional independence at 90 days (53% vs. 56%, p=0.54). In ordinal multivariate analysis, collateral grade (OR 1.4, p=0.007) but not sex, age, or history of atrial fibrillation predicted improved TICI recanalization. In logistic (Figure) and ordinal regression analysis, the impact of delayed OTR was no different between men and women (1% versus 1.2% likelihood of worsened mRS outcome per 5 minute delay, p=0.27). Conclusions: In our prospective multicenter randomized cohort of nearly 400 patients undergoing ET, presentation and treatment characteristics of women were similar to men. Women were equally likely to achieve successful recanalization and good clinical outcomes.