Tokyo Metropolitan Stroke Emergency Medical Services for Interventional Stroke Treatment: The Tama-REgistry of Acute Thrombectomy (TREAT) Study

OBJECTIVE

It is not clear how patients with large vessel occlusion (LVO) who have undergone mechanical thrombectomy (MT) were transported to hospitals by emergency medical services. Here, we describe the current status of the stroke delivery system in a large city.

METHODS

We investigated data from 328 patients (male, n = 199; average age, 74.8 ± 12.9 years) who underwent MT at 12 facilities in the Tama area of Tokyo, between January 2015 and December 2017. The patients were classified according to the destination institution as Stroke A eligible (group A, n = 266 [8.2%]), Tertiary critical care center (group T; n = 35 [10.7%]), and other destinations such as emergency rooms (group O; n = 27 [8.2%]), and then reasons for using Emergency Medical Service (EMS) services and outcomes were compared among the groups.

RESULTS

Rates of milder stroke, and middle cerebral artery occlusion were significantly higher in group A than T, whereas that of vertebral-basilar artery occlusion was significantly lower in group A than in groups T and O. The amount of elapsed time from door to picture (DTP) was significantly lower in group A. The time from onset to recanalization, as well as rates of successful recanalization and favorable outcomes (90-day modified Rankin scale 0-2) did not significantly differ regardless of destination.

CONCLUSIONS

Most patients with LVO in the Tama area were categorized into group A. DTP was significantly lower in group A.

Differences in Safety and Efficacy of Endovascular Treatment for Acute Ischemic Stroke : A Propensity Score Analysis of Intracranial Atherosclerosis-Related Occlusion versus Embolism

PURPOSE

The prognosis after endovascular treatment (EVT) of acute arterial occlusions due to intracranial atherosclerotic disease (ICAD) may differ from those due to embolism. The aim was to evaluate whether safety and efficacy of EVT differ among patients with middle cerebral artery (MCA) M1 occlusion from ICAD or embolism.

METHODS

A database review was conducted to identify EVT patients with acute MCA M1 occlusion from November 2013 to December 2018.The patients were divided into the ICAD group and embolic group according to the etiology of occlusion. Using propensity score analysis, patients with ICAD-related occlusion and embolism underwent 1:1 matching. Angiographic results, complications, and clinical outcomes were compared.

RESULTS

A total of 217 patients (ICAD: 51; embolism: 166) were identified. After propensity score matching, 45 patients with ICAD-related occlusion and 45 with embolism were matched. All baseline covariates except atrial fibrillation were statistically indistinguishable. The rate of successful reperfusion (modified Thrombolysis in Cerebral Infarction [mTICI] 2b-3) was similar between the two groups, while the rate of mTICI 3 in the ICAD group was higher. No statistical difference was observed in the rate of postprocedural intracranial hemorrhage. The rate of favorable outcome (modified Rankin Scale [mRS] ≤2) and mortality at 90 days was comparable.

CONCLUSION

This propensity score analysis demonstrated that the EVT patients with acute ICAD-related MCA M1 occlusion had similar angiographic and clinical outcomes compared to those with M1 embolism on a similar baseline condition.

Early versus Delayed Extracranial-Intracranial Bypass Surgery in Symptomatic Atherosclerotic Occlusion

BACKGROUND

Clinical trials of extracranial-intracranial (EC-IC) bypass surgery studied patients in subacute and chronic stage after ischemic event.

OBJECTIVE

To investigate the short-term outcomes of EC-IC bypass in progressive acute ischemic stroke or recent transient ischemic attacks.

METHODS

The study was a retrospective review at a single tertiary referral center from 2008 to 2015. Inclusion criteria consisted of EC-IC bypass within 1 yr of last ischemic symptoms ipsilateral to atherosclerotic occlusion of internal carotid or middle cerebral artery. Early bypass group who underwent surgery within 7 d of last ischemic symptoms were compared to late bypass group who underwent surgery >7 d from last ischemic symptom. The primary endpoint was perioperative ischemic or hemorrhagic stroke or intracranial hemorrhage within 7 d of surgery.

RESULTS

Of 126 patients who underwent EC-IC bypass during the period, 81 patients met inclusion criteria, 69 (85%) persons had carotid artery occlusion, 7 (9%) had proximal MCA occlusion, and 5 (6%) had both. Early surgery had a 31% (9/29) perioperative stroke rate compared to 11.5% (6/52) of patients undergoing late bypass (P = .04). Of patients with acute stroke within 7 d of surgery, 41% (7/17) had perioperative stroke within 7 d (P = .07). Six of nine patients (67%) with blood pressure dependent fluctuation of neurologic symptoms had perioperative stroke (P = .049).

CONCLUSION

EC-IC bypass in setting of acute symptomatic stroke within 1 wk may confer higher risk of perioperative stroke. Patients undergoing expedited or urgent bypass for unstable or fluctuating stroke symptoms might be at highest risk for perioperative stroke.

MRI characteristics in acute ischemic stroke patients with preceding direct oral anticoagulant therapy as compared to vitamin K antagonists

Background

Despite the utility of neuroimaging in the diagnostic and therapeutic management of patients with acute ischemic stroke (AIS), imaging characteristics in patients with preceding direct oral anticoagulants (DOAC) compared to vitamin K antagonists (VKA) have hardly been described. We aimed to determine presence of large vessel occlusion (LVO), thrombus length, infarction diameter, and occurrence of hemorrhagic transformation in AIS patients with preceding DOAC as compared to VKA therapy.

Methods

Using a prospectively collected cohort of AIS patients, we performed univariate and multivariable regression analyses regarding imaging outcomes. Additionally, we provide a sensitivity analysis for the subgroup of patients with confirmed therapeutic anticoagulation.

Results

We included AIS in patients with preceding DOAC (N = 75) and VKA (N = 61) therapy, median age 79 (IQR 70–83), 39% female. Presence of any LVO between DOAC and VKA patients (29.3% versus 37.7%, P = 0.361), and target LVO for endovascular therapy (26.7% versus 27.9%, P = 1.0) was equal with a similar occlusion pattern. DOAC as compared to VKA were associated with a similar rate of target LVO for EVT (aOR 0.835, 95% CI 0.368–1.898). The presence of multiple lesions and characteristics of the thrombus were similar in DOAC and VKA patients. Acute ischemic lesion diameter in real world patients was equal in patients taking DOAC as compared to VKA. Lesion diameter in VKA patients (median 13 mm, IQR 6–26 versus median 20 mm, IQR 7–36, P = 0.001), but not DOAC patients was smaller in the setting of confirmed therapeutic VKA. The frequency of radiological hemorrhagic transformation and symptomatic intracranial hemorrhage in OAC patients was low. Sensitivity analysis considering only patients with confirmed therapeutic anticoagulation did not change any of the results.

Conclusion

Preceding DOAC treatment showed equal rates of LVO and infarct size as compared to VKA in AIS patients. This study adds to the knowledge of imaging findings in AIS patients with preceding anticoagulation.

Asymmetrical Bioimpedance in the Anterior Circulation for Urgent Stratification of suspected Stroke (ABACUS Stroke): study protocol for a diagnostic accuracy study

BACKGROUND

Early identification and treatment of stroke improve outcome. Ischaemic stroke due to large vessel occlusion (LVO) benefits from time-critical thrombectomy but this is only available in highly specialised healthcare services. Cerebral Bioimpedance Asymmetry (CBA) measurement obtained with the portable and rapid Cerebrotech Visor™ System device may be able to identify certain types of stroke including LVO. This test could be deployed pre-hospital and used to immediately direct patients to the most appropriate healthcare service for treatment. This study is evaluating the diagnostic accuracy of CBA measurements obtained from a real-world population of suspected stroke.

METHODS

Study design: Prospective observational cohort study.Setting: A hyperacute stroke unit and neuroscience centre in North East England.Participants: Adults with a paramedic assigned diagnosis of suspected stroke arriving at hospital within 6 hours of symptom onset.Index Test: Cerebral Bioimpedance Asymmetry measurement performed using the Cerebrotech Visor™ System. Measurement values produce continuous data (range 0 -100); pre-defined threshold for positive state ≥ 10.Reference Standard Tests: Standard CT brain +/- CT/MR angiography, and expert clinician opinion will establish the following clinical outcomes which constitute the suspected stroke population: ischaemic stroke +/- large vessel occlusion; symptomatic severe anterior vessel stenosis; large (≥60ml) and small (<60mls) vessel intracerebral haemorrhage; transient ischaemic attack; stroke mimic conditions; prior territorial stroke.Analyses: Sensitivity, specificity, negative and positive predictive values, area under the Receiver Operating Characteristic curve for identification of i) "complex stroke" (ischaemic stroke with large vessel occlusion or symptomatic severe anterior vessel stenosis or intracerebral haemorrhage ≥60ml or prior territorial stroke) and ii) ischaemic stroke with large vessel occlusion in isolation.Sample size: 124 participants.

DISCUSSION

The results from this study will determine how accurately CBA measurement using the Cerebrotech Visor™ System can identify key stroke types within the suspected stroke population. Acceptable diagnostic performance would be an important step forwards for access to time-critical treatments.

TRIAL REGISTRATION

Registered with ISRCTN (identifier: ISRCTN79169844) on 06/08/2018.

Outcome of patients with large vessel occlusion in the anterior circulation and low NIHSS score

BACKGROUND

Optimal management of patients with large vessel occlusion (LVO) and low NIHSS score is unknown, which was the aim to investigate in this study.

METHODS

This is a retrospective analysis of a prospective single tertiary care centre 14-year cohort of patients with LVO in the anterior circulation and NIHSS score ≤ 5 on admission. Outcome was analysed according to primary intended therapy.

RESULTS

Among 185 patients (median age 67.4 years), 52.4% received primary conservative therapy (including 26.8% secondary reperfusion in case of secondary neurological deterioration), 12.4% IV thrombolysis (IVT) only and 35.1% primary endovascular therapy (EVT). 95 (51.4%) patients experienced neurological deterioration until 3 months. Primary-IVT-only and primary-EVT compared to conservative-therapy patients had better 3 months' outcome (54.5% vs. 30.8%: _adjustedOR 6.02; _adjustedp = 0.004 for mRS 0-1 and 54.7% vs. 30.8%: _adjustedOR 5.09; _adjustedp = 0.002, respectively). Also mRS shift analysis favored primary-IVT-only and primary-EVT patients (_adjustedOR 6.25; _adjustedp = 0.001 and _adjustedOR 3.14; _adjustedp = 0.003). Outcome in primary-IVT-only vs. primary-EVT patients did not differ significantly. Patients who received secondary EVT because of neurological deterioration after primary-conservative-therapy had worse 3 months' outcome than primary-EVT patients (20.8% vs. 30.8%: _adjustedOR 0.24; _adjustedp = 0.047 for mRS 0-1 and _adjustedOR 0.31; _adjustedp = 0.019 in mRS shift analysis). Survival and symptomatic intracranial haemorrhage did not differ amongst groups.

CONCLUSIONS

Our data indicate that primary IVT and/or EVT may be better than primary conservative therapy in patients with LVO in the anterior circulation and low NIHSS score. Furthermore, primary EVT was better than secondary EVT in case of neurological deterioration. There is an unmet need for RCTs to find the optimal therapy for this patient group.

Single mean arterial blood pressure drops during stroke thrombectomy under general anaesthesia are associated with poor outcome

Background

We examined the influence of periprocedural blood pressure (BP), especially critical BP drops, on 3-month functional outcome in stroke patients undergoing mechanical thrombectomy (MT) under general anaesthesia (GA).

Methods

We screened all patients with anterior circulation large vessel occlusion receiving MT under GA at our centre from January 2011 to June 2016 and selected those who had continuous invasive periinterventional BP monitoring. Clinical and radiological data were prospectively collected as part of an ongoing cohort study, monitoring data were extracted from electronic anaesthesia records. We used uni- and multivariable regression to investigate the association of BP values with unfavourable outcome, defined as modified Rankin Scale scores 3–6 3 months post-stroke.

Results

115 patients were included in this study (mean age 65.3 ± 13.0 years, 55.7% male). Periinterventional systolic, diastolic, and mean arterial BP (MAP) values averaged across MT had no effect on outcome. However, single BP drops were related to unfavourable outcome, with absolute MAP drops showing the highest association compared to both systolic and relative BP drops (with reference to pre-interventional values). The BP value with the strongest association with unfavourable outcome was identified as an MAP ever < 60 mmHg (p = 0.01) with a pronounced effect in patients with poor collaterals. An MAP < 60 mmHg remained independently associated with poor functional outcome in multivariable analysis (p < 0.01).

Conclusions

For patients undergoing MT under GA, single MAP drops < 60 mmHg are independently related to unfavourable 3-month outcome. Therefore, every effort should be made to prevent periinterventional hypotensive episodes, especially below this threshold.

Electronic supplementary material

The online version of this article (10.1007/s00415-020-09701-x) contains supplementary material, which is available to authorized users.

Large Vessel Occlusion in the Acute Stroke Patient: Identification, Treatment, and Management

Acute ischemic stroke is a major cause of death and disability in the United States. Historically, acute stroke patients were treated with intravenous (IV) thrombolysis. Patients with large vessel occlusions (LVOs) should be offered mechanical thrombectomy, with or without IV thrombolysis, in an extended window up to 24 hours of last known well. Both treatment options are the standard of care for a patient with an LVO. It is critical that the intensive care unit nurse understand new treatment indications for LVO strokes, and the priorities of nursing care with medical and endovascular intervention.

Recanalization is the Key for Better Outcome of Thrombectomy in Basilar Artery Occlusion

PURPOSE

Patients with basilar artery occlusion (BAO) were excluded from previous randomized controlled trials (RCTs) of endovascular treatment (ET) for acute ischemic stroke, but are commonly treated in clinical practice. This study aimed at analyzing predictors of functional outcome of ET in patients with BAO to improve patient selection for ET.

METHODS

Consecutive patients with BAO who received ET over a 2-year time period were prospectively studied. Baseline characteristics, procedural and outcome data were evaluated. Outcome was assessed by the modified Rankin Scale (mRS) 90 days after stroke. Multivariate regression analyses were performed to identify predictors of outcome across the range of the mRS, of poor outcome (mRS 5-6) and independent outcome (mRS 0-2).

RESULTS

A total of 39 patients with BAO (median age: 75 years, 67% male) were included. Median baseline National Institutes of Health Stroke Scale (NIHSS) score was 24. Intravenous thrombolysis therapy (IVT) was administered in 56%. Successful recanalization assessed by a modified thrombolysis in cerebral infarction (TICI) score ≥2b was achieved in 82%. Independent outcome was observed in 30% of patients with successful recanalization, but in no patient with failed recanalization. Poor outcome was observed in 47% and 86%, respectively. Successful recanalization was associated with lower scores on the mRS at 90 days (p = 0.035), and failed recanalization was associated with an odds ratio of 13.6 for poor outcome (p = 0.036).

CONCLUSION

Reperfusion is the major predictor of functional outcome in BAO in clinical practice. Failed recanalization resulted in a 13-fold increase of the risk of poor outcome. Successful recanalization is crucial to achieve a better functional outcome in BAO.

Field Assessment of Critical Stroke by Emergency Services for Acute Delivery to a Comprehensive Stroke Center: FACE2AD

Patients with acute ischemic stroke (AIS) due to large vessel occlusion (LVO) should be triaged to an endovascular-capable hospital by the emergency medical service (EMS). We designed a prehospital LVO prediction scale based on EMS assessments. In the derivation cohort, 1157 patients transferred to our hospital by the EMS because of suspected stroke within 24 h of onset were retrospectively examined. Factors associated with AIS due to LVO were identified based on the EMS assessment, and a prehospital scale identifying LVO was developed. The accuracy of this scale was validated in 502 consecutive patients who were transferred to 4 stroke centers, and its accuracy was compared with those of 4 previously reported scales. AIS due to LVO was diagnosed in 149 of 1157 patients (13%) in the derivation cohort. One point each was assigned for facial palsy, arm weakness, consciousness impairment (cannot say his/her name), atrial fibrillation, and diastolic blood pressure ≤ 85 mmHg, with two points for conjugate eye deviation (FACE₂AD scale). In the derivation cohort, with the optimal cut-point of FACE₂AD ≥ 3 determined by the area under the curve (AUC; 0.88; 95% confidence interval 0.87-0.90), sensitivity, specificity, positive predictive value, and negative predictive value for FACE₂AD to predict LVO were 0.85, 0.80, 0.39, and 0.97, respectively. In the validation cohort, the FACE₂AD scale had higher accuracy, with an AUC value of 0.84 for predicting LVO compared with the other scales (all p < 0.01). The FACE₂AD scale is a simple, reliable tool for identifying AIS due to LVO by the EMS.

Case-Control Study of Endovascular Thrombectomy in a Canadian Stroke Center

BACKGROUND

Although the efficacy of endovascular thrombectomy (EVT) for acute ischemic stroke caused by intracranial anterior circulation large vessel occlusion (LVO) is proven, demonstration of local effectiveness is critical for health system planning and resource allocation because of the complexity and cost of this treatment.

METHODS

Using our prospective registry, we identified all patients who underwent EVT for out-of-hospital LVO stroke from February 1, 2013 through January 31, 2017 (n = 44), and matched them 1:1 in a hierarchical fashion with control patients not treated with EVT based on age (±5 years), prehospital functional status, stroke syndrome, severity, and thrombolysis administration. Demographics, in-hospital mortality, discharge disposition from acute care, length of hospitalization, and functional status at discharge from acute care and at follow-up were compared between cases and controls.

RESULTS

For EVT-treated patients (median age 66, 50% women), the median onset-to-recanalization interval was 247 min, and successful recanalization was achieved in 30/44 (91%). Alteplase was administered in 75% of cases and 57% of controls (p = 0.07). In-hospital mortality was 11% among the cases and 36% in the control group (p = 0.006); this survival benefit persisted during follow-up (p = 0.014). More EVT patients were discharged home from acute care (50% vs. 18%, p = 0.002). Among survivors, there were nonsignificant trends in favor of EVT for median length of hospitalization (14 vs. 41 days, p = 0.11) and functional independence at follow-up (51% vs. 32%, p = 0.079).

CONCLUSION

EVT improved survival and decreased disability. This demonstration of single-center effectiveness may help facilitate expansion of EVT services in similar health-care jurisdictions.

Emergency management of stroke in the era of mechanical thrombectomy

Emergency management of stroke has been directed at the delivery of recombinant tissue plasminogen activator (tPA) in a timely fashion. Because of the many limitations attached to the delivery of tPA and the perceived benefits accrued to tPA, its use has been limited. Mechanical thrombectomy, a far superior therapy for the largest and most disabling strokes, large vessel occlusions (LVOs), has changed the way acute strokes are managed. Aside from the rush to deliver tPA, there is now a need to identify LVO and refer those patients with LVO to physicians and facilities capable of delivering urgent thrombectomy. Other parts of emergency department management of stroke are directed at identifying and mitigating risk factors for future strokes and at preventing further damage from occurring. We review here the most recent literature supporting these advances in stroke care and present a framework for understanding the role that emergency physicians play in acute stroke care.

Large Vessel Occlusion in Acute Ischemic Stroke Patients: A Dual-Center Estimate Based on a Broad Definition of Occlusion Site

BACKGROUND

Accurate assessment of the frequency of large vessel occlusion (LVO) is important to determine needs for neurointerventionists and thrombectomy-capable stroke facilities. Current estimates vary from 13% to 52%, depending on acute ischemic stroke (AIS) definition and methods for AIS and LVO determination. We sought to estimate LVO prevalence among confirmed and suspected AIS patients at 2 comprehensive US stroke centers using a broad occlusion site definition: internal carotid artery (ICA), first and second segments of the middle cerebral artery (MCA M1,M2), the anterior cerebral artery, vertebral artery, basilar artery, or the proximal posterior cerebral artery.

METHODS

We analyzed prospectively maintained stroke databases of patients presenting to the centers between January and December 2017. ICD-10 coding was used to determine the number of patients discharged with an AIS diagnosis. Computed tomography angiography (CTA) or magnetic resonance angiography (MRA) was reviewed to determine LVO presence and site. Percentages of patients with LVO among the confirmed AIS population were reported.

RESULTS

Among 2245 patients with an AIS discharge diagnosis, 418 (18.6%:95% confidence interval [CI] 17.3%-20.0%) had LVO documented on CTA or MRA. Most common occlusion site was M1 (n=139 [33.3%]), followed by M2 (n=114 [27.3%]), ICA (n=69[16.5%]), and tandem ICA-MCA lesions (n=44 [10.5%]). Presentation National Institutes of Health Stroke Scale scores were significantly different for different occlusion sites (P=.02).

CONCLUSIONS

The LVO prevalence in our large series of consecutive AIS patients was 18.6% (95% CI 17.3%-20.0%). Despite the use of a broad definition, this estimate is less than that reported in most previous studies.

Recanalization of Emergent Large Intracranial Vessel Occlusion through Intravenous Thrombolysis: Frequency, Clinical Outcome, and Reperfusion Pattern

BACKGROUND

According to a recent meta-analysis, 1 out of 10 patients with emergent large intracranial vessel occlusion (ELVO) causing stroke have recanalization after intravenous thrombolysis (IVT) alone. However, rate, clinical outcome, and recanalization pattern of this phenomenon are poorly understood.

OBJECTIVES AND METHODS

Patients with ELVO recanalized only by IVT were analyzed, and frequency of recanalization, clinical outcome, safety variables, and reperfusion pattern were assessed. These patients were compared to a group of patients with ELVO who underwent endovascular thrombectomy with or without prior IVT.

RESULTS

Successful or sufficient recanalization after IVT alone occurred in 81 of 760 patients (10.6%) with ELVO who had been referred for endovascular thrombectomy. These 81 patients (group 1) were compared to a group of patients receiving endovascular thrombectomy with prior IVT (group 2) or without (group 3). A good clinical outcome at 90 days was seen in 61.7% of patients in group 1, 32.2% in group 2, and 34.5% in group 3 (p < 0.001). The 3 groups had no significant differences in intracranial hemorrhage. IVT was not independently associated with symptomatic intracranial hemorrhage, parenchymal hematoma, or subarachnoid hemorrhage. Mortality at 90 days was 9.9% in group 1, 20.7% in group 2, and 29.6% in group 3 (p < 0.001). After adjusting for all relevant variables, outcome and mortality differences were nonsignificant. No difference in the rate of successful reperfusion (modified treatment in cerebral ischemia [mTICI] 2b/3) was found. A reperfusion mTICI 3 was achieved in 18.5% in group 1, 60.7% in group 2, and 57.1% in group 3 (p < 0.001). Patients in group 1 had lower chance of achieving a complete recanalization (mTICI 3) compared to patients in group 2, OR 0.15 (95% CI 0.08-0.29) and in group 3, OR 0.17 (95% CI 0.09-0.32; p < 0.001).

CONCLUSIONS

Primary IVT in ELVO caused a recanalization rate of 10.6%, making endovascular treatment either unnecessary or impossible. Early recanalization of ELVO with only IVT is associated with a 61.7% independence rate at 90 days and similar successful reperfusion rates (mTICI2b/3) compared to ELVO treated with endovascular treatment, with or without previous IVT. However, recanalization only through IVT achieves a lower rate of mTICI 3 reperfusion when compared to endovascular treatment.

Diagnostic value of transcranial ultrasonography for selecting subjects with large vessel occlusion: a systematic review

Introduction

A number of pre-hospital clinical assessment tools have been developed to triage subjects with acute stroke due to large vessel occlusion (LVO) to a specialised endovascular centre, but their false negative rates remain high leading to inappropriate and costly emergency transfers. Transcranial ultrasonography may represent a valuable pre-hospital tool for selecting patients with LVO who could benefit from rapid transfer to a dedicated centre.

Methods

Diagnostic accuracy of transcranial ultrasonography in acute stroke was subjected to systematic review. Medline, Embase, PubMed, Scopus, and The Cochrane Library were searched. Published articles reporting diagnostic accuracy of transcranial ultrasonography in comparison to a reference imaging method were selected. Studies reporting estimates of diagnostic accuracy were included in the meta-analysis.

Results

Twenty-seven published articles were selected for the systematic review. Transcranial Doppler findings, such as absent or diminished blood flow signal in a major cerebral artery and asymmetry index ≥ 21% were shown to be suggestive of LVO. It demonstrated sensitivity ranging from 68 to 100% and specificity of 78–99% for detecting acute steno-occlusive lesions. Area under the receiver operating characteristics curve was 0.91. Transcranial ultrasonography can also detect haemorrhagic foci, however, its application is largely restricted by lesion location.

Conclusions

Transcranial ultrasonography might potentially be used for the selection of subjects with acute LVO, to help streamline patient care and allow direct transfer to specialised endovascular centres. It can also assist in detecting haemorrhagic lesions in some cases, however, its applicability here is largely restricted. Additional research should optimize the scanning technique. Further work is required to demonstrate whether this diagnostic approach, possibly combined with clinical assessment, could be used at the pre-hospital stage to justify direct transfer to a regional thrombectomy centre in suitable cases.

Endovascular Treatment of Acute Ischemic Stroke Due to Intracranial Atherosclerotic Large Vessel Occlusion : A Systematic Review

OBJECTIVE

To evaluate the efficacy and safety of endovascular treatment (ET) of acute ischemic stroke (AIS) caused by intracranial atherosclerotic large vessel occlusion (ICAS-LVO).

METHODS

A systemic review and meta-analysis were conducted on studies published between July 2005 and October 2018 on the outcomes of ET in patients with AIS due to ICAS-LVO. The outcomes of the ICAS-LVO and embolic LVO groups were also compared.

RESULTS

A total of 17 studies including 1315 subjects with ICAS-LVO were included. In the single-arm meta-analysis, the pooled estimates of successful recanalization rate, favorable outcomes, symptomatic intracranial hemorrhage and mortality were 88% (95% CI (95% confidence interval), 84-92%), 52% (95% CI, 47-56%), 5% (95% CI, 3-7%) and 15% (95% CI, 12-19%) respectively. The preferred primary treatment was stent-retriever thrombectomy (84.1%) and the preferred rescue treatment was stent implantation with or without percutaneous transluminal angioplasty (PTA, 32.7%). In the double-arm meta-analysis, the incidence of symptomatic intracranial hemorrhage was lower in the ICAS-LVO compared to the embolic-LVO group (OR (odds ratio) = 0.60, 95% CI, 0.46-0.77, p < 0.01), whereas the implementation of rescue treatment (OR = 5.94, 95% CI, 3.15-11.19, p < 0.01) and stenting rate (OR = 10.06, 95%CI, 4.43-22.85, p < 0.01) were higher in the ICAS-LVO group. Other parameters were similar in both groups.

CONCLUSION

The use of ET is a safe and effective therapeutic option for AIS due to ICAS-LVO. Stent-retriever thrombectomy and stent-implement are the preferred primary and rescue therapies respectively for ICAS-LVO. Less symptomatic intracranial hemorrhage and higher stenting were observed in the ICAS-LVO compared to the embolic-LVO group.

Effect of short-term blood pressure variability on functional outcome after intra-arterial treatment in acute stroke patients with large-vessel occlusion

Background

Endovascular treatment (EVT) is advocated for acute ischaemic stroke with large-vessel occlusion (LVO), but perioperative periods are challenging. This study investigated the relationship between post-EVT short-term blood pressure variability (BPV) and early outcomes in LVO patients.

Methods

We retrospectively reviewed 72 LVO patients undergoing EVT between June 2015 and June 2018. Hourly systolic and diastolic blood pressures (SBP and DBP, respectively) were recorded in the first 24 h post-EVT. BPV were evaluated as standard deviation (SD), coefficient of variation (CV), and successive variation (SV) separately for SBP and DBP. Functional independence at 3 months was defined as a modified Rankin Scale (mRS) score of 0–2.

Results

For 58.3% patients with favorable outcomes, the median National Institutes of Health Stroke Scale and Alberta Stroke Program Early CT scores on admission were 14 and 8, respectively. The maximum SBP ([154.3 ± 16.8] vs. [163.5 ± 15.6], P = 0.02), systolic CV ([8. 8% ± 2.0%] vs. [11.0% ± 1.8], P < 0.001), SV ([11.4 ± 2.3] vs. [14.6 ± 2.0], P < 0.001), and SD ([10.5 ± 2.4] vs. [13.8 ± 3.9], P < 0.001) were lower in patients with favorable outcomes. On multivariable logistic regression analysis, systolic SV (OR: 4.273, 95% CI: 1.030 to 17.727, P = 0.045) independently predicted unfavorable prognosis. The area under the curve was 0.868 (95% CI: 0.781 to 0.955, P < 0.001), and sensitivity and specificity were 93.3% and 73.8%, respectively, showing excellent predictive value for 3-month poor-outcomes.

Conclusions

Decreased systolic SV following intra-arterial therapies result in favorable outcomes at 3 months. Systolic SV may be a novel predictor of functional prognosis in LVO patients.

Supplementary information

Supplementary information accompanies this paper at 10.1186/s12883-019-1457-5.

Diagnostic accuracy of clinical tools for assessment of acute stroke: a systematic review

INTRODUCTION

Recanalisation therapy in acute ischaemic stroke is highly time-sensitive, and requires early identification of eligible patients to ensure better outcomes. Thus, a number of clinical assessment tools have been developed and this review examines their diagnostic capabilities.

METHODS

Diagnostic performance of currently available clinical tools for identification of acute ischaemic and haemorrhagic strokes and stroke mimicking conditions was reviewed. A systematic search of the literature published in 2015-2018 was conducted using PubMed, EMBASE, Scopus and The Cochrane Library. Prehospital and in-hospital studies with a minimum sample size of 300 patients reporting diagnostic accuracy were selected.

RESULTS

Twenty-five articles were included. Cortical signs (gaze deviation, aphasia and neglect) were shown to be significant indicators of large vessel occlusion (LVO). Sensitivity values for selecting subjects with LVO ranged from 23 to 99% whereas specificity was 24 to 97%. Clinical tools, such as FAST-ED, NIHSS, and RACE incorporating cortical signs as well as motor dysfunction demonstrated the best diagnostic accuracy. Tools for identification of stroke mimics showed sensitivity varying from 44 to 91%, and specificity of 27 to 98% with the best diagnostic performance demonstrated by FABS (90% sensitivity, 91% specificity). Hypertension and younger age predicted intracerebral haemorrhage whereas history of atrial fibrillation and diabetes were associated with ischaemia. There was a variation in approach used to establish the definitive diagnosis. Blinding of the index test assessment was not specified in about 50% of included studies.

CONCLUSIONS

A wide range of clinical assessment tools for selecting subjects with acute stroke has been developed in recent years. Assessment of both cortical and motor function using RACE, FAST-ED and NIHSS showed the best diagnostic accuracy values for selecting subjects with LVO. There were limited data on clinical tools that can be used to differentiate between acute ischaemia and haemorrhage. Diagnostic accuracy appeared to be modest for distinguishing between acute stroke and stroke mimics with optimal diagnostic performance demonstrated by the FABS tool. Further prehospital research is required to improve the diagnostic utility of clinical assessments with possible application of a two-step clinical assessment or involvement of simple brain imaging, such as transcranial ultrasonography.

[Prehospital management of acute stroke : Using the example of Saarland ambulance services]

BACKGROUND

The preclinical care strategy was changed after reevaluation of endovascular thrombectomy in the S2k guideline of the German Neurological Society (DGN). Severe strokes should be directly transferred to neurovascular centers (model "mothership"). The severity of a stroke should be determined using the LAMS (Los Angeles Motor Scale) score.

MATERIALS AND METHODS

The general conditions of preclinical care of patients with stroke in the Saarland are presented. The key figures and statistical data of clinic assignments in the adapted care strategy are evaluated.

RESULTS

The 2018 data from the Saarland Ambulance Services indicate that 9.1% of all preclinical emergencies are diagnosed with "transient ischemic attack (TIA)/insult/bleeding"; 97.1% of these patients were admitted to one of the 10 hospitals in Saarland with a stroke unit. A care time at the emergency site of 20 min was observed in 78.2%, a prehospital time of 60 min in 90.1% of the missions. Preclinically, severe strokes with LAMS score ≥4 were detected in 19.2% of all stroke patients; 71.6% of these severe strokes were assigned to one of two neurovascular centers in the Saarland.

CONCLUSIONS

With good traffic and hospital infrastructure in Saarland, severe strokes can be treated primarily in neurovascular centers. Differentiated care requirements with monitoring of key figures in medical quality management and clear agreements with the target hospitals in the implementation of a common care strategy are essential.

Understanding the Radial Force of Stroke Thrombectomy Devices to Minimize Vessel Wall Injury: Mechanical Bench Testing of the Radial Force Generated by a Novel Braided Thrombectomy Assist Device Compared to Laser-Cut Stent Retrievers in Simulated MCA Vessel Diameters

Background

Recent reports have raised various concerns about the risk of vessel wall injury while withdrawing current laser-cut stent retrievers during active strut apposition to the vessel walls. The development of braided thrombectomy assist devices in conjunction with aspiration systems may be gentler on the fragile brain vessels and more optimized with regard to the radial force (RF) for vessel diameters of proximal (M1) and distal (M2) large vessel occlusions (LVOs).

Methods

Mechanical bench testing of the RF was performed using a radial compression station mounted on a tensile testing machine. The total RF in newtons (N) generated in vessels with diameters ranging from 2.25 to 3 mm as seen in proximal LVOs (∼M1), and in vessel diameters ranging from 1.5 to 2.24 mm as seen in distal LVOs (∼M2), was measured. The outer diameter of each stent was recorded, and an RF ≤1 N was grouped as "low," while an RF >1 N was grouped as "high" for this analysis.

Results

The total RFs of all laser-cut stent retrievers were all higher in the simulated M2 vessels (>1 N) than in the M1 vessels (<1 N), whereas the total RFs of the braided thrombectomy assist devices were uniformly low in both the simulated M1 and the simulated M2 vessels.

Conclusions

Novel braided thrombectomy assist devices in conjunction with aspiration systems have lower RFs than existing laser-cut stent retrievers in M1 and M2 vessel diameters. Further in vivo studies are needed to delineate the impact of lowering the RF on vessel wall integrity.

Thrombectomy for a Patient with Concomitant Acute Cervical Internal Carotid and Middle Cerebral Artery Occlusion: Video Case

We present the case of a 62-yr-old female who presented with ground-level fall and new onset of left-sided weakness of 30 min duration. CT angiogram revealed right ICA pseudo-occlusion and thrombus filling the right proximal M1 segment of the right MCA. On detailed neurological exam patient was noted to have NIHSS of 25. Patient was started on IV TPA infusion and was taken to interventional angiography suite after an informed consent was obtained. Diagnostic angiography was performed which demonstrated critical stenosis of the right proximal internal carotid artery. Right carotid artery stenting and balloon angioplasty of the carotid stent with distal embolic protection device was performed. Post carotid stent angiogram once again confirmed proximal right M1 pseudo-occlusion in the right MCA distribution. The clot was removed using a stent retriever, thus achieving complete recanalization (TICI 3) of the right cerebral hemisphere. The patient returned to baseline neurological status and a 1 mo follow-up diagnostic angiogram revealed patent carotid stent. Following the case presentation, we present the nuances of acute ischemic stroke management of large vessel occlusion with an emphasis on technical nuances, recent published guidelines1 and the literature.2-8.

Proteomic profiling of plasma biomarkers in acute ischemic stroke due to large vessel occlusion

Background

Acute ischemic stroke (AIS) due to large vessel occlusion (LVO) is a devastating cerebrovascular disorder, which could benefit from collateral circulation. Proteins associated with acute LVO pathogenesis and endothelial function may appear in blood samples of AIS patients due to LVO, thus permitting development of blood-based biomarkers for its diagnosis and prognosis.

Methods

This study is a single-center, retrospective, observational case–control trial. Consecutive patients who presented at the Department of Neurology of Tongji Hospital were recruited from July 2016 to April 2018. In the discovery phase, a proteomic approach with iTRAQ-based LC–MS/MS was used to investigate the altered proteomic pattern in plasma from patients with AIS due to LVO. In the validation study, Western blots was used to identify biomarkers associated with stroke diagnosis as well as their prognostic value associated with different collateral statuses.

Results

For this exploratory study, the proteomic analysis of plasma from 40 patients with AIS due to LVO and 20 healthy controls revealed seven differentially expressed proteins with a 1.2/0.83-fold or greater difference between groups. The four elevated proteins, PPBP (1.58 ± 0.78 vs 0.98 ± 0.37; P < 0.001), THBS1 (1.13 ± 0.88 vs 0.43 ± 0.26; P < 0.001), LYVE1 (1.61 ± 0.55 vs 0.97 ± 0.50; P < 0.001), and IGF2 (1.19 ± 0.42 vs 0.86 ± 0.24; P < 0.001), were verified by Western blots analysis in an independent cohort including 33 patients and 33 controls. A strong interaction was observed between the four-protein panel and the diagnosis of AIS due to LVO (AUC 0.947; P < 0.001). Furthermore, IGF2, LYVE1, and THBS1 were closely associated with collateral status (IGF2 0.115, 95% CI 0.016–0.841, P = 0.033; LYVE1 0.183, 95% CI 0.036–0.918, P = 0.039; THBS1 4.257, 95% CI 1.273–14.228, P = 0.019), and proved to be independent predictors of good outcome (IGF2 0.115, 95% CI 0.015–0.866, P = 0.036; LYVE1 0.028, 95% CI 0.002–0.334, P = 0.005; THBS1 3.294, 95% CI 1.158–9.372, P = 0.025) at a 3-month follow-up.

Conclusions

The identified 4-biomarker panel could provide diagnostic aid to the existing imaging modalities for AIS due to LVO, and the prognostic value of IGF2, LYVE1, and THBS1 was proved in predicting functional outcomes related to collateral status.

Trial registration ClinicalTrials.gov NCT 03122002. Retrospectively registered April 20, 2017. URL of trial registry record: https://www.clinicaltrials.gov/ct2/show/NCT03122002?term=NCT+03122002&rank=1

Electronic supplementary material

The online version of this article (10.1186/s12967-019-1962-8) contains supplementary material, which is available to authorized users.

Acute Left M1 Stroke With Critical Left Internal Carotid Artery Stenosis: Video Case

We present the case of a 68-yr-old woman who presented with an acute left middle cerebral artery syndrome. Noninvasive angiography obtained 13 h after last known well time demonstrated both left M1-segment middle cerebral artery (MCA) occlusion and near-complete occlusion of the left internal carotid artery (ICA) just distal to the carotid bifurcation. Intervention was offered given the sizeable mismatch demonstrated by computed tomography (CT) perfusion imaging. After administering loading doses of aspirin and clopidogrel, we initially performed carotid angioplasty and stenting to open the internal carotid artery, which was otherwise impassible. Subsequently, thrombectomy of the M1 occlusion was performed with direct aspiration. Postprocedural imaging demonstrated preservation of the at-risk brain parenchyma. The patient demonstrated significant improvement in strength and speech after the procedure, and she was discharged to an inpatient rehabilitation center for further treatment. The patient and her family gave consent for this report.

Intravenous Tissue Plasminogen Activator for Large Vessel Ischemic Stroke - Is There Still a Role?

While the efficacy of Intravenous tissue plasminogen activator (tPA) is well established, its impact on large vessel occlusion (LVO) is controversial. Whether IV tPA should be bypassed in favor of endovascular thrombectomy (MT) will be addressed. Compelling evidence exists to suggest tPA administration might be bypassed in tPA eligible patients in favor of MT for LVO. A trial of MT with patients randomized for IV tPA within the 4.5-h time window should conducted at comprehensive stroke centers demonstrating equipoise between time to tPA or MT with time to treatment from ED arrival of 45 min. We may do well to consider the systems pathway taken by interventional cardiologists 15 years ago.

Longer 6-mm Diameter Stent Retrievers Are Effective for Achieving Higher First Pass Success with Fibrin-Rich Clots

First pass success (FPS) can be defined as in vitro retrieval of clot in a single pass during mechanical thrombectomy (MT) for acute large vessel occlusion (LVO). Despite advancements in MT technology, retrieval of fibrin-rich clots remains a challenge. Therefore, the effect of stent retriever length on FPS for fibrin-rich clots was investigated by using Solitaire^TM 6 × 40 versus 6 × 30 mm devices with a balloon guide catheter (BGC) or distal access catheter (DAC) and sheath, in an in vitro model of anterior circulation neurovascular anatomy. Additionally, vascular safety of the Solitaire^TM 6 × 40 versus 6 × 30 mm devices was evaluated in a porcine model for differences in: luminal thrombus, inflammation, endothelial coverage, fibrin deposits, smooth muscle cell loss, elastic lamina and adventitia disruption, intimal hyperplasia, and lumen reduction, at 0, 30, and 90 days post-treatment. In vitro overall FPS was measured as: Solitaire^TM 6 × 40 (95%) and Solitaire^TM 6 × 30 (67%). FPS for clot location in middle cerebral artery was: (a) BGC (6 × 40 mm: 100%; 6 × 30 mm: 100%; n = 8); (b) DAC with 088 sheath (6 × 40 mm: 83%; 6 × 30 mm: 33%; n = 12). FPS for clot location in internal carotid artery was: (a) BGC (6 × 40 mm: 100%; 6 × 30 mm: 80%; n = 11); (b) DAC with 088 sheath (6 × 40 mm: 100%; 6 × 30 mm: 67%; n = 10). Stent length had a significant effect (Fisher's exact test; p < 0.05) on FPS. In vivo evaluation in the porcine model showed no difference in vascular safety parameters between the Solitaire^TM 6 × 40 and 6 × 30 mm devices (p > 0.05) at all time points in the study. Longer stent retrievers may be safe and effective in improving FPS for fibrin-rich clots in in vitro and in vivo models of LVO.