Revolution in acute ischaemic stroke care: a practical guide to mechanical thrombectomy

A qualitative exploration of ambulance clinician behaviour and decision making to identify factors influencing on-scene times for suspected stroke patients in North East England

Aims/objectives

Ambulance clinician assessment of suspected stroke patients aims to provide rapid access to specialist care, however regional and national data show increasing pre-hospital times. This study explored paramedic views about factors contributing to on-scene time (OST) for suspected stroke patients, with a view to identifying opportunities for future interventions, to reduce OST.

Methods

Views of paramedics from one regional service on factors influencing OST were explored using a qualitative approach. Semi-structured interviews with volunteers were recorded, transcribed and analysed using thematic analysis.

Results

Interviews were conducted with 13 paramedics between August and November 2021. Five interlinked themes were identified and described a range of factors influencing OST: 'Initial assessment and sources of information' describes how clinicians make assessments based on initial presentation, influenced by pre-arrival information from ambulance control and family members / bystanders at the scene, and how this influences OST.'Suitability for treatment and interventions' describes how paramedics consider actions such as the face, arms, speech test, cannulation, electrocardiograms and neurological assessments while recognising that pre-hospital interventions for suspected stroke are limited.'The environment' describes the influence of incident setting on OST, including the overall process needed to transport the patient to appropriate care.'Hospital interactions' describes how interactions with hospital staff influenced paramedic actions and OST.'Changing practice' describes the influence of experience and interaction with hospital staff leading to changes in paramedic practice over time.

Conclusion

This study provides insight into how UK paramedics spend time on scene with stroke patients. Multiple factors influencing OST were identified which signpost opportunities for interventions designed to reduce OST. Standardising on-scene assessments for stroke patients, refining communication processes between ambulance services and hospital stroke services and increasing availability of stroke continuing professional development for paramedics were all identified as potential targets for improving OST.

In silico study of combination thrombolytic therapy with alteplase and mutant pro-urokinase for fibrinolysis in ischemic stroke

The synergistic advantage of combining tissue plasminogen activator (tPA) with pro-urokinase (proUK) for thrombolysis has been demonstrated in several in vitro experiments, and a single site proUK mutant (m-proUK) has been developed for better stability in plasma. Based on these studies, combination thrombolytic therapy with intravenous tPA and m-proUK has been suggested as a promising treatment for patients with ischemic stroke. This paper evaluates the efficacy and safety of the dual therapy by computational simulations of pharmacokinetics and pharmacodynamics coupled with a local fibrinolysis model. Seven dose regimens are simulated and compared with the standard intravenous tPA monotherapy. Our simulation results provide more insights into the complementary reaction mechanisms of tPA and m-proUK during clot lysis and demonstrate that the dual therapy can achieve a similar recanalization time (about 50 min) to tPA monotherapy, while keeping the circulating fibrinogen level within a normal range. Specifically, our results show that for all dual therapies with a 5 mg tPA bolus, the plasma concentration of fibrinogen remains stable at around 7.5 μM after a slow depletion over 50 min, whereas a rapid depletion of circulating fibrinogen (to 5 μM) is observed with the standard tPA therapy, indicating the potential advantage of dual therapy in reducing the risk of intracranial hemorrhage. Through simulations of varying dose combinations, it has been found that increasing tPA bolus can significantly affect fibrinogen level but only moderately improves recanalization time. Conversely, m-proUK doses and infusion duration exhibit a mild impact on fibrinogen level but significantly affect recanalization time. Therefore, future optimization of dose regimen should focus on limiting the tPA bolus while adjusting m-proUK dosage and infusion rate. Such adjustments could potentially maximize the therapeutic advantages of this combination therapy for ischemic stroke treatment.

Healthcare-Seeking Delays in Acute Ischemic Stroke Patients: The Influence of Gender, Immigrant Status, and Educational Background

Purpose

Timely medical attention is crucial for patients with Acute Ischemic Stroke (AIS), as delays can significantly impact therapeutic outcomes. These delays are influenced by a combination of socio-cultural, educational, and clinical factors.

Patients and Methods

An in-depth analysis was conducted to assess the prevalence and median duration of healthcare-seeking delays in AIS patients. The study specifically investigated the independent impacts of sociocultural and clinical determinants on these delays, with a focus on immigrant status, gender disparities, and educational levels. Multivariate regression analysis was employed to identify these independent effects while controlling for potential confounding factors.

Results

Among 1419 AIS patients, 82.52% (n = 1171) experienced delays exceeding 2 hours from symptom onset of symptoms to hospital arrival. The median delay was 12.3 hours. Immigrant populations encountering longer delays compared to native groups. Younger males (<45 years) and elderly females were more prone to delay in healthcare-seeking. Identified independent risk factors for delay included male gender (OR = 1.65 [95% CI:1.14-2.48]), self-acknowledged diabetes (OR = 2.50 [95% CI:1.21-5.17]), small vessel (OR = 2.07 [95% CI:1.27-3.36]), and wake stroke (OR = 7.04 [95% CI:3.69-13.44]). Educational background (high school and above), GCS score with 3-8 points (OR = 0.52 [95% CI:0.09-0.69]), understanding stroke-related knowledge (OR = 0.26 [95% CI:0.09-0.44]), conscious disturbance (OR = 0.25 [95% CI:0.10-0.62]) and limb weakness (OR=0.21[95% CI:0.21-0.49]) are protective factors for timely treatment.

Conclusion

Immigrant populations experienced longer delays from symptom onset to hospital arrival. The crucial roles of education and knowledge about stroke underscore the need for enhanced health literacy campaigns and public awareness, with a targeted focus on younger males and elderly females.

GPR39 Knockout Worsens Microcirculatory Response to Experimental Stroke in a Sex-Dependent Manner

No current treatments target microvascular reperfusion after stroke, which can contribute to poor outcomes even after successful clot retrieval. The G protein-coupled receptor GPR39 is expressed in brain peri-capillary pericytes, and has been implicated in microvascular regulation, but its role in stroke is unknown. We tested the hypothesis that GPR39 plays a protective role after stroke, in part due to preservation of microvascular perfusion. We generated GPR39 knockout (KO) mice and tested whether GPR39 gene deletion worsens capillary blood flow and exacerbates brain injury and functional deficit after focal cerebral ischemia. Stroke was induced in male and female GPR39 KO and WT littermates by 60-min middle cerebral artery occlusion (MCAO). Microvascular perfusion was assessed via capillary red blood cell (RBC) flux in deep cortical layers in vivo using optical microangiography (OMAG). Brain injury was assessed by measuring infarct size by 2,3,5-triphenyltetrazolium chloride staining at 24 h or brain atrophy at 3 weeks after ischemia. Pole and cylinder behavior tests were conducted to assess neurological function deficit at 1 and 3 weeks post-stroke. Male but not female GPR39 KO mice exhibited larger infarcts and lower capillary RBC flux than WT controls after stroke. Male GPR39 KO mice also exhibited worse neurologic deficit at 1 week post-stroke, though functional deficit disappeared in both groups by 3 weeks. GPR39 deletion worsens brain injury, microvascular perfusion, and neurological function after experimental stroke. Results indicate that GPR39 plays a sex-dependent role in re-establishing microvascular flow and limiting ischemic brain damage after stroke.

[Current approaches in the treatment and rehabilitation of patients with neurological diseases after COVID-19. Resolution of the International Experts Forum]

Despite the significant shift in global attention away from the pandemic, the problem of a new coronavirus infection remains important in the medical community. Almost 3 years after the start of the COVID-19 pandemic the issues of rehabilitation and management of delayed manifestations and sequelae of the disease are especially important. According to numerous available data, the new coronavirus infection is characterized by multiorgan lesions. Respiratory dysfunction, clotting disorders, myocardial dysfunction and various arrhythmias, acute coronary syndrome, acute renal failure, GI disorders, hepatocellular damage, hyperglycemia and ketosis, dermatological complications, ophthalmological symptoms and neurological disorders may be found. Significant prevalence of the latter in the post-coronavirus period necessitated this International Expert Forum to develop unified approaches to the management of patients with neurological complications and sequelae of new coronavirus infection based on practical experience and considering the scientific information available on COVID-19. The expert council developed a resolution formulating the tactics for the management of patients with neurological manifestations of COVID-19.

Successful endovascular thrombectomy 8 days after onset of acute ischemic stroke: A case report

Endovascular thrombectomy (EVT) is the recommended option for acute ischemic stroke (AIS) patients with large vessel occlusion (LVO) that within 6 h onset of stroke. The EVT treatment time window has been extended to 24 h in carefully selected patients by DAWN trial. Recent evidences indicated that some patients presented beyond 24 h still potentially benefit from EVT treatment. Herein, we describe one case of successful delayed EVT in a 50-year-old male AIS patient with an 8-day history of left middle cerebral artery occlusion. Before surgery, CT perfusion demonstrated a marked left hypoperfusion with penumbra volume of 127 mL and ischemic core volume of 10 mL. EVT was performed with complete recanalization and significant improvement in his neurological deficits at 90-days post-surgery follow-up. In future, more randomized clinical trials are warranted to further confirm the safety, efficacy, as well as the applicable population of delayed EVT.

Identification of infarct core and ischemic penumbra using computed tomography perfusion and deep learning

Purpose

The size and location of infarct and penumbra are key to decision-making for acute ischemic stroke (AIS) management. CT perfusion (CTP) software estimate infarct and penumbra volume using contralateral hemisphere relative thresholding. This approach is not robust and widely contested by the scientific community. In this study, we investigate the use of deep learning-based algorithms to efficiently locate infarct and penumbra tissue on CTP hemodynamic maps.

Approach

CTP scans were retrospectively collected for 60 and 59 patients in the infarct only and infarct + penumbra substudies respectively. Commercial CTP software was used to generate cerebral blood flow, cerebral blood volume, mean transit time, time to peak, and delay time maps. U-Net-shaped architectures were trained to segment infarct or infarct + penumbra. Test-time-augmentation, ensembling, and watershed segmentation were used as postprocessing techniques. Segmentation performance was evaluated using Dice coefficients (DC) and mean absolute volume errors (MAVE).

Results

The algorithm segmented infarct tissue resulted in DC of 0.64 ± 0.03 (0.63, 0.65), and MAVE of 4.91 ± 0.94 (4.5, 5.32) mL. In comparison, the commercial software predicted infarct with a DC of 0.31 ± 0.17 (0.26, 0.36) and MAVE of 9.77 ± 8.35 (7.12, 12.42) mL. The algorithm was able to segment infarct + penumbra with a DC of 0.61 ± 0.04 (0.6, 0.63), and MAVE of 6.51 ± 1.37 (5.91, 7.11) mL. In comparison, the commercial software predicted infarct + penumbra with a DC of 0.3 ± 0.19 (0.25, 0.35) and MAVE of 9.18 ± 7.55 (7.25, 11.11) mL.

Conclusions

Use of deep learning algorithms to assess severity of AIS in terms of infarct and penumbra volume is precise and outperforms current relative thresholding methods. Such an algorithm would enhance the reliability of CTP in guiding treatment decisions.

Dysphagia assessment in ischemic stroke after mechanical thrombectomy: When and how?

Background

Dysphagia is a frequent symptom in acute ischemic stroke (AIS). Endovascular treatment (EVT) has become the standard of care for acute stroke secondary to large vessel occlusion. Although standardized guidelines for poststroke dysphagia (PSD) management exist, they do not account for this setting in which patients receive EVT under general anesthesia. Therefore, the aim of this study was to evaluate PSD prevalence and severity, as well as an appropriate time point for the PSD evaluation, in patients undergoing EVT under general anesthesia (GA).

Methods

We prospectively included 54 AIS patients undergoing EVT under GA. Fiberoptic Endoscopic Evaluation of Swallowing (FEES) was performed within 24 h post-extubation in all patients. Patients presenting significant PSD received a second FEES-assessment to determine the course of dysphagia deficits over time. Dysphagia severity was rated according the Fiberoptic Dysphagia Severity Scale (FEDSS).

Results

At first FEES (FEES 1) assessment, performed in the median 13 h (IQR 5-17) post-extubation, 49/54 patients (90.7%) with dysphagia were observed with a median FEDSS of 4 (IQR 3-6). Severe dysphagia requiring tube feeding was identified in 28/54 (51.9%) subjects, whereas in 21 (38.9%) patients early oral diet with certain food restrictions could be initiated. In the follow up FEES examination conducted in the median 72 h (IQR 70-97 h) after initial FEES 34/49 (69.4%) patients still presented PSD. Age (p = 0.030) and ventilation time (p = 0.035) were significantly associated with the presence of PSD at the second FEES evaluation. Significant improvement of dysphagia frequency (p = 0.006) and dysphagia severity (p = 0.001) could be detected between the first and second dysphagia assessment.

Conclusions

PSD is a frequent finding both immediately within 24 h after extubation, as well as in the short-term course. In contrast to common clinical practice, to delay evaluation of swallowing for at least 24 h post-extubation, we recommend a timely assessment of swallowing function after extubation, as 50% of patients were safe to begin oral intake. Given the high amount of severe dysphagic symptoms, we strongly recommend application of instrumental swallowing diagnostics due to its higher sensitivity, when compared to clinical swallowing examination. Furthermore, advanced age, as well as prolonged intubation, were identified as significant predictors for delayed recovery of swallowing function.

Impact of time between thrombolysis and endovascular thrombectomy on outcomes in patients with acute ischaemic stroke

BACKGROUND

Benefits of endovascular thrombectomy (ET) after intravenous thrombolysis (IVT) for patients with acute ischaemic stroke (AIS) have been demonstrated, but analyses of the relationship between IVT-ET time delay and functional outcomes among patients receiving both treatments are lacking.

METHODS

We used data from the "Berlin-Specific Acute Treatment in Ischaemic and haemorrhAgic stroke with Long-term outcome" (B-SPATIAL) registry. Between January 1st, 2016 and December 31st, 2019, we included patients who received both IVT and ET. The primary outcome was the 3-month ordinal modified Rankin scale (mRS) score. The IVT-ET time delay was analyzed in categories and continuously. We used adjusted ordinal logistic regression to estimate common odds ratios (cOR) and 95% confidence intervals (CI). Secondary analyses involved flexible modeling of IVT-ET delay and dichotomous outcomes.

RESULTS

Of 11,049 patients, 714 who received IVT followed by ET were included. Compared with having an IVT-ET window >120 min (reference), for an IVT-ET window < 30 min, we obtained adjusted cORs for mRS of 0.41 (95% CI: 0.22 to 0.78); and 0.52 (95% CI: 0.33 to 0.82) for 30 to 120 min. Secondary analyses also found protective effects of shorter time delays against "poor" functional outcomes at 3 months.

CONCLUSIONS

In patients with AIS, shorter IVT-ET intervals were associated with better 3-month functional outcomes. While the time-to-IVT and time-to-ET include the time until medical attention is received, the IVT-ET time delays fall entirely within the domain of medical management and thus might be easier to optimize.

Predictors and clinical outcomes of post-coronary artery bypass grafting cerebrovascular strokes

Background

Despite the improved medical and surgical managements, still there is a significant risk of developing acute cerebrovascular strokes after coronary artery bypass grafting (CABG). Our objectives were to study the immediate and long-term outcomes after CABG and to identify the possible predictors of post-CABG strokes.

Results

Between January 2016 and August 2020, 410 adult patients, mostly males (82.2%), were retrospectively enrolled after CABG. Acute postoperative strokes occurred in 31 (7.5%) patients; of them, 30 (96.8%) patients had ischemic stroke, while 1 (3.2%) had hemorrhagic stroke. Mechanical thrombectomy was done in two cases. The patients who developed acute cerebral stroke had significantly higher admission (p = 0.02) and follow-up (p < 0.001) SOFA scores, higher arterial blood lactate level (p < 0.001), longer hospitalization (p < 0.001) and more hospital mortality (p < 0.001) compared with the patients who did not develop stroke. Kaplan–Meier curves for 5-year mortality showed increased risk in those patients with postoperative stroke (HR: 23.03; 95% CI: 6.10–86.92, p < 0.001). After multivariate regression, the predictors of early postoperative stroke were carotid artery stenosis (CAS), postoperative atrial fibrillation, cardiopulmonary bypass time, prior cerebral stroke, admission SOFA score and chronic kidney disease (CKD). The predictors of late cerebrovascular stroke were CAS, combined CABG and valve surgery, CKD, atrial fibrillation, prior stroke and HbA1c.

Conclusions

The development of post-CABG acute cerebrovascular stroke is associated with longer hospitalization, multiple morbidities and increased mortality. Careful assessment and management of risk factors especially atrial fibrillation and carotid artery stenosis should be implemented to decrease this substantial complication after CABG.

Endovascular recanalization of acute ischemic stroke patients exhibiting large vessel occlusion after pulmonary lobectomy: case series

Objective

We analyzed the outcomes of patients suffering acute ischemic stroke (AIS) with large vessel occlusion (LVO) soon after pulmonary lobectomy.

Methods

We retrospectively reviewed the clinical records of patients who underwent pulmonary lobectomy to treat primary lung cancer. We retrieved clinical characteristics and the incidence of AIS with LVO. The clinical courses of patients who experienced AIS were reviewed.

Results

In 10 (0.3%) of 3406 patients, AIS with LVO developed soon (within 3 days) after pulmonary lobectomy. The lung resection site was on the left in eight patients (80%). All patients underwent thrombectomy and achieved complete recanalization (Thrombolysis in Cerebral Infarction [TICI] 3). The average time between symptom onset and recanalization was 165.5 min. Nine (90%) patients exhibited favorable outcomes (modified Rankin scale [mRS] score ≤ 2) at the 3-month follow-up.

Conclusion

Endovascular therapy effectively treats AIS with LVO that develops after lung surgery, and direct aspiration is a promising strategy. A large, multicenter study is warranted to further confirm these findings.

Transient Middle Cerebral Artery Occlusion with an Intraluminal Suture Enables Reproducible Induction of Ischemic Stroke in Mice

Ischemic stroke is a leading cause of mortality and chronic disability worldwide, underscoring the need for reliable and accurate animal models to study this disease's pathology, molecular mechanisms of injury, and treatment approaches. As most clinical strokes occur in regions supplied by the middle cerebral artery (MCA), several experimental models have been developed to simulate an MCA occlusion (MCAO), including transcranial MCAO, micro- or macro-sphere embolism, thromboembolisation, photothrombosis, Endothelin-1 injection, and - the most common method for ischemic stroke induction in murine models - intraluminal MCAO. In the intraluminal MCAO model, the external carotid artery (ECA) is permanently ligated, after which a partially-coated monofilament is inserted and advanced proximally to the common carotid artery (CCA) bifurcation, before being introduced into the internal carotid artery (ICA). The coated tip of the monofilament is then advanced to the origin of the MCA and secured for the duration of occlusion. With respect to other MCAO models, this model offers enhanced reproducibility regarding infarct volume and cognitive/functional deficits, and does not require a craniotomy. Here, we provide a detailed protocol for the surgical induction of unilateral transient ischemic stroke in mice, using the intraluminal MCAO model. Graphic abstract: Overview of the intraluminal monofilament method for transient middle cerebral artery occlusion (MCAO) in mouse.

A Patient With (Initially) Non-Persistent Vertigo – A Posterior Circulation Stroke Case

Posterior circulation strokes are responsible for about 20-25% of all ischemic strokes. Recognition and diagnosis of posterior circulation strokes or transient ischemic attacks is more difficult than that of other stroke types, being frequently misdiagnosed in acute setting/emergency evaluation - up to more than three times as often as anterior circulation strokes.

In accordance with the guidelines in effect at the time of this case presentation, thrombolysis and medical therapy are the mainstay treatment. Mechanical thrombectomy is emerging as a treatment option in posterior vessel occlusion but randomized clinical trials are still lacking.

Multiphysics Modelling and Simulation of Thrombolysis via Activated Platelet-Targeted Nanomedicine

PURPOSE

This study establishes a multiphysics simulation platform for both conventional and targeted thrombolysis using tissue plasminogen activator (tPA). Based on our computational results, the effects of therapeutic parameters on the dynamics of thrombolysis and the risk of side effects are investigated.

METHODS

The model extends our previously developed one-dimensional(1D) mathematical models for fibrinolysis by incorporating targeted thrombolysis. It consists of two parts: (i) a coupled mathematical model of systemic pharmacokinetics (PK) and pharmacodynamics (PD) and local PD in a 1D occluded artery, and (ii) a mechanistic model for a targeted thrombolytic system via activated platelet-targeted tPA-loaded nanovesicles (tPA-NV), with model parameters derived from our in vitro experiments. A total of 16 therapeutic scenarios are simulated by varying the clot location and composition as well as the dosing regimen with free tPA or tPA-NV.

RESULTS

Our simulation results indicate that tPA-NV offers several advantages over free tPA for thrombolysis. It reduces systemic exposure of tPA, thereby minimising the risk of bleeding complications. Simulations with different tPA-NV doses reveal that tPA-NV at 10% of the recommended dose can be as effective as the standard regimen with the full recommended dose of free tPA, demonstrating the potential of our tPA-NV as a new thrombolytic strategy with a reduced tPA dose. Moreover, faster recanalisation can be achieved with tPA-NV, especially for platelet-rich(or fibrin-poor) clots.

CONCLUSIONS

Our simulation platform for thrombolysis with well-tuned model parameters can be used to evaluate and optimise treatment regimens of existing and new thrombolytic therapies via benefit/risk assessment under various therapeutic scenarios.

Mechanical thrombectomy versus intravenous alteplase alone in acute isolated posterior cerebral artery occlusion: a systematic review

BACKGROUND

Acute isolated posterior cerebral artery occlusions (aPCAOs) were excluded or under-represented in major randomized trials of mechanical thrombectomy (MT). The benefit of MT in comparison to intravenous tissue plasminogen activator (alteplase; IV-tPA) alone in these patients remains controversial and uncertain.

METHODS

We performed a systematic search of PubMed, MEDLINE, and EMBASE databases for articles comparing MT with or without bridging IV-tPA and IV-tPA alone for aPCAO using keywords ('posterior cerebral artery', 'thrombolysis' and 'thrombectomy') with Boolean operators. Extracted data from patients reported in the studies were pooled into groups (MT vs IV-tPA alone) for comparison. Estimated rates for favorable outcome (modified Rankin scale score 0-2), symptomatic intracranial hemorrhage (sICH), and mortality were extracted.

RESULTS

Seven articles (201 MT patients, 64 IV-tPA) were included, all retrospective. There was no statistically significant difference between pooled groups in median age, median presentation National Institutes of Health Stroke Scale (NIHSS) score, PCAO segment, and median time from symptom onset to puncture or needle. The recanalization rate was significantly higher in the MT group than the IV-tPA group (85.6% vs 53.1%, p<0.00001). Odds ratios for favorable outcome (OR 1.5, 95% CI 0.8 to 2.5), sICH (OR 1.1, 95% CI 0.2 to 5.5), and mortality (OR 1.4, 95% CI 0.5 to 3.6) did not significantly favor any modality.

CONCLUSIONS

We found no significant differences in odds of favorable outcome, sICH, and mortality in MT and IV-tPA in comparable aPCAO patients, despite superior MT recanalization rates. Equipoise remains regarding the optimal treatment modality for these patients.

Statistical shape model of vessel centerline for endovascular paths comparison in mechanical thrombectomy

Endovascular interventions are experiencing an important development. Despite many advantages of this type of intervention, catheter navigation is still a cause of difficulties or failure. Mechanical thrombectomy is one of these interventions where navigation difficulties are related to the ability to navigate the aortic arch and access the carotid. These difficulties are due to the selection of adequate catheters and guides for a specific anatomy and to the technical gesture to operate. The objective of this work is to propose a method to find similar endovascular navigation paths from pre-existing patients to support intervention in mechanical thrombectomy. For each patient, iso-centerlines of the aortic arch and supra-aortic trunks are extracted from pre-operative magnetic resonance angiography volume. A statistical shape model is computed from these vascular structure iso-centerlines. Euclidean distance between vectors of statistical shape model modes is used to compare endovascular navigation paths. A set of 6 patient cases was used to compute the statistical shape model. For validation, an additional set of 5 patient cases was considered to generate new iso-centerlines.Retrieval of closest iso-centerlines were correct in more than 95% of cases with the proposed method while this percentage goes down to 43% with Euclidean distance between 3D points of iso-centerlines.Clinical relevance-The presented method allows physicians to retrieve past navigation paths similar to a new one. Used in planning, this could allow to anticipate navigation difficulties in mechanical thrombectomy.

Use of quantitative angiographic methods with a data-driven model to evaluate reperfusion status (mTICI) during thrombectomy

PURPOSE

Intra-procedural assessment of reperfusion during mechanical thrombectomy (MT) for emergent large vessel occlusion (LVO) stroke is traditionally based on subjective evaluation of digital subtraction angiography (DSA). However, semi-quantitative diagnostic tools which encode hemodynamic properties in DSAs, such as angiographic parametric imaging (API), exist and may be used for evaluation of reperfusion during MT. The objective of this study was to use data-driven approaches, such as convolutional neural networks (CNNs) with API maps, to automatically assess reperfusion in the neuro-vasculature during MT procedures based on the modified thrombolysis in cerebral infarction (mTICI) scale.

METHODS

DSAs from patients undergoing MTs of anterior circulation LVOs were collected, temporally cropped to isolate late arterial and capillary phases, and quantified using API peak height (PH) maps. PH maps were normalized to reduce injection variability. A CNN was developed, trained, and tested to classify PH maps into 2 outcomes (mTICI 0,1,2a/mTICI 2b,2c,3) or 3 outcomes (mTICI 0,1,2a/mTICI 2b/mTICI 2c,3), respectively. Ensembled networks were used to combine information from multiple views (anteroposterior and lateral).

RESULTS

The study included 383 DSAs. For the 2-outcome classification, average accuracy was 81.0% (95% CI, 79.0-82.9%), and the area under the receiver operating characteristic curve (AUROC) was 0.86 (0.84-0.88). For the 3-outcome classification, average accuracy was 64.0% (62.0-66.0), and AUROC values were 0.85 (0.83-0.87), 0.74 (0.71-0.77), and 0.78 (0.76-0.81) for the mTICI 0,1,2a, mTICI 2b, and mTICI 2c,3 classes, respectively.

CONCLUSION

This study demonstrated the feasibility of using hemodynamic information in API maps with data-driven models to autonomously assess intra-procedural reperfusion during MT.

The Safety of Intra-arterial Tirofiban during Endovascular Therapy after Intravenous Thrombolysis

BACKGROUND AND PURPOSE

The safety and efficacy of tirofiban during endovascular therapy in patients undergoing intravenous thrombolysis with recombinant IV tPA remain unclear. This study aimed to investigate the safety and efficacy of intra-arterial tirofiban use during endovascular therapy in patients treated with IV tPA.

MATERIALS AND METHODS

Using a multicenter registry, we enrolled patients with acute ischemic stroke who underwent endovascular therapy. Safety outcomes included postprocedural parenchymal hematoma type 2 and/or thick subarachnoid hemorrhage, intraventricular hemorrhage, and 3-month mortality. Efficacy outcomes included the successful reperfusion rate, postprocedural reocclusion, and good outcomes at 3 months (mRS scores of 0-2). The tirofiban effect on the outcomes was evaluated using a multivariable analysis while adjusting for potential confounders.

RESULTS

Among enrolled patients, we identified 314 patients with stroke (279 and 35 patients in the no tirofiban and tirofiban groups, respectively) due to an intracranial artery occlusion who underwent endovascular therapy with intravenous thrombolysis. A multivariable analysis revealed no association of intra-arterial tirofiban with postprocedural parenchymal hematoma type and/or thick subarachnoid hemorrhage (adjusted OR, 1.07; 95% CI, 0.20-4.10; P = .918), intraventricular hemorrhage (adjusted OR, 0.43; 95% CI, 0.02-2.85; P = .467), and 3-month mortality (adjusted OR, 0.38; 95% CI, 0.04-1.87; P = .299). Intra-arterial tirofiban was not associated with good outcome (adjusted OR, 2.22; 95% CI, 0.89 -6.12; P = .099).

CONCLUSIONS

Using intra-arterial tirofiban during endovascular therapy after IV tPA could be safe.

Delayed diapedesis of CD8 T cells contributes to long-term pathology after ischemic stroke in male mice

OBJECTIVE

Stroke is a debilitating disorder with significant annual mortality and morbidity rates worldwide. Immune cells are recruited to the injured brain within hours after stroke onset and can exhibit either protective or detrimental effects on recovery. However, immune cells, including CD8 T cells, persist in the injured brain for weeks, suggesting a longer-term role for the adaptive immune system during functional recovery. The aim of this study was to determine if the delayed secondary diapedesis of CD8 T cells into the ischemic brain negatively impacts functional recovery after transient ischemic stroke in male mice.

RESULTS

Mice exhibited an increased number of leukocytes in the ipsilesional hemispheres at 14 days (3-fold; p < 0.001) and 30 days (2.2-fold; p = 0.02) after transient middle cerebral artery occlusion (tMCAo) compared to 8 days post-tMCAo, at which time acute neuroinflammation predominantly resolves. Moreover, mice with higher ipsilesional CD8 T cells at 30 days (R² = 0.52, p < 0.01) exhibited worse functional recovery. To confirm a detrimental role of chronic CD8 T cell diapedesis on recovery, peripheral CD8 T cells were depleted beginning 10 days post-tMCAo. Delayed CD8 T cell depletion improved motor recovery on the rotarod (F_(1,28) = 4.264; p = 0.048) compared to isotype control-treated mice. CD8 T cell-depleted mice also exhibited 2-fold (p < 0.001) reduced leukocyte infiltration at 30 days post-tMCAo. Specifically, macrophage, neutrophil, and CD4 T cell numbers were reduced in the ipsilesional hemisphere of the CD8 T cell-depleted mice independent of inflammatory status of the post-stroke CNS (e.g. microglial phenotype and cytokine production). RNAseq identified a unique profile for brain infiltrating CD8 T cells at 30 days post-tMCAo, with 46 genes differentially expressed relative to CD8 T cells at 3 days post-tMCAo.

CONCLUSION

Our data reveal a role for CD8 T cells in the chronic phase post-stroke that can be therapeutically targeted. We demonstrate long-term CD8 T cell recruitment into the ipsilesional hemisphere that affects both immune cell numbers present in the injured brain and functional recovery through one month after stroke onset.

Microsurgical Embolectomy in the Current Era of Pharmacological and Mechanical (Endovascular) Thrombolysis-A Reappraisal

Introduction

Microsurgical embolectomy though is the oldest known recanalization technique is being dismissed in favor of the latest mechanical endovascular techniques for the management of acute large vessel occlusion.

Aim and Objective

We aim to highlight the role of microsurgical embolectomy in the current era of pharmacological and mechanical (endovascular) thrombolysis.

Methods

An outline of the microsurgical embolectomy technique is described along with its current indications, advantages, and disadvantages.

Results

It carries higher complete (TICI 3) revascularization rates with lower risk of distal embolic events especially in cases with high clot burdens; but is more labor-intensive and has longer reperfusion time in comparison to endovascular methods along with the requirement of highly skilled neurovascular surgeons to perform it quickly.

Conclusion

Microsurgical embolectomy is an important indispensable recanalization technique in the armamentarium of vascular neurosurgeons.

Types of intraparenchymal hematoma as a predictor after revascularization in patients with anterior circulation acute ischemic stroke

Background:

Intracranial hemorrhage after revascularization for acute ischemic stroke is associated with poor outcomes. Few reports have examined the relationship between parenchymal hematoma after revascularization and clinical outcomes. This retrospective study aimed to investigate the risk factors and clinical outcomes of parenchymal hematoma after revascularization for acute ischemic stroke.

Methods:

Ninety-three patients underwent revascularization for anterior circulation acute ischemic stroke. Patient characteristics and clinical outcomes were compared between patients with and without post procedural parenchymal hematoma using the following parameters: age, sex, occlusion location, presence of atrial fibrillation, diffusion-weighted imaging-Alberta stroke program early computed tomography score (DWI-ASPECTS), National Institute of Health Stroke Scale (NIHSS) score, recombinant tissue plasminogen activator, thrombolysis in cerebral infarction > 2b, door-to-puncture time, onset-to-recanalization time, number of passes, and modified Rankin Scale scores.

Results:

Parenchymal hematomas were not significantly correlated with age, sex, occlusion location, atrial fibrillation, DWI-ASPECTS, NIHSS score, recombinant tissue plasminogen activator, thrombolysis in cerebral infarction > 2b, door-to-puncture time, onset-to-recanalization time, and number of passes, but were significantly correlated with poor clinical outcomes (P = 0.001) and absence of the anterior communicating artery evaluated using pre procedural time-of-flight magnetic resonance angiography (P = 0.03).

Conclusion:

Parenchymal hematoma was a predictor of poor outcomes. In particular, the absence of the anterior communicating artery on pre procedural time-of-flight magnetic resonance angiography is a potential risk factor for parenchymal hematoma after revascularization for anterior circulation acute ischemic stroke.

Use of biplane quantitative angiographic imaging with ensemble neural networks to assess reperfusion status during mechanical thrombectomy

Digital subtraction angiography (DSA) is the main imaging modality used to assess reperfusion during mechanical thrombectomy (MT) when treating large vessel occlusion (LVO) ischemic strokes. To improve this visual and subjective assessment, hybrid models combining angiographic parametric imaging (API) with deep learning tools have been proposed. These models use convolutional neural networks (CNN) with single view individual API maps, thus restricting use of complementary information from multiple views and maps resulting in loss of relevant clinical information. This study investigates use of ensemble networks to combine hemodynamic information from multiple bi-plane API maps to assess level of reperfusion. Three-hundred-eighty-three anteroposterior (AP) and lateral view DSAs were retrospectively collected from patients who underwent MTs of anterior circulation LVOs. API peak height (PH) and area under time density curve (AUC) maps were generated. CNNs were developed to classify maps as adequate/inadequate reperfusion as labeled by two neuro-interventionalists. Outputs from individual networks were combined by weighting each output, using a grid search algorithm. Ensembled, AP-AUC, AP-PH, lateral-AUC, and lateral-PH networks achieved accuracies of 83.0% (95% confidence-interval: 81.2%-84.8%), 74.4% (72.0%-76.7%), 74.2% (72.8%-75.7%), 74.9% (72.2%-77.7%), and 76.9% (74.4%-79.5%); area under receiver operating characteristic curves of 0.86 (0.84-0.88), 0.81 (0.79-0.83), 0.83 (0.81-0.84), 0.82 (0.8-0.84), and 0.84 (0.82-0.87); and Matthews correlation coefficients of 0.66 (0.63-0.70), 0.48 (0.43-0.53), 0.49 (0.46-0.52), 0.51 (0.45-0.56), and 0.54 (0.49-0.59) respectively. Ensembled network performance was significantly better than individual networks (McNemar's p-value<0.05). This study proved feasibility of using ensemble networks to combine hemodynamic information from multiple bi-plane API maps to assess level of reperfusion during MTs.

Mechanical Thrombectomy using Distal Access Catheters: Current Status and Future Prospects

BACKGROUND AND PURPOSE

Mechanical Thrombectomy (MT) using modern devices has proved to be efficacious in re-establishing intracranial circulation and reduced procedural times. We outline a number of endovascular techniques utilizing the distal access catheter, the circumstances where they are applicable, and the outcomes achieved.

METHODS

In this review, we describe a variety of endovascular techniques with distal access catheter, deployed with and without the stent retriever device gained from our experience of performing over 700 procedures in 10 years of providing a 24/7 service within the national framework of a hyperacute stroke centre.

RESULTS

We used distal access catheter techniques for intracranial support during a stent-retriever thrombectomy or thrombo-suction on its own. When used as a sole suction device, or combined with a stent-retriever, we have been able to provide a rapid route to successful reperfusion, with minimal complications related to our endovascular procedures. We can report distal access catheter techniques works well when access to thrombi involves navigation through tortuous vessel anatomy, notably when convoluted loops in the cervical internal carotid artery are encountered. We suggest use of the distal access catheter techniques in thrombectomy procedures for steep-angle Middle Cerebral Artery occlusions, M2/M3 occlusion, and for basilar occlusion, where thrombectomy via suction alone proved to be adequate.

CONCLUSION

In this pictorial review, we have demonstrated techniques where distal access catheter when used as a sole suction device, or combined with a stent-retriever, has been able to provide a rapid route to successful reperfusion, with minimal complications related to our endovascular procedures.

Endovascular model of ischemic stroke in swine guided by real-time MRI

Modeling stroke in animals is essential for testing efficacy of new treatments; however, previous neuroprotective therapies, based on systemic delivery in rodents failed, exposing the need for model with improved clinical relevance. The purpose of this study was to develop endovascular approach for inducing ischemia in swine. To achieve that goal, we used intra-arterial administration of thrombin mixed with gadolinium and visualized the occlusion with real-time MRI. Placement of the microcatheter proximally to rete allowed trans-catheter perfusion of the ipsilateral hemisphere as visualized by contrast-enhanced perfusion MR scans. Dynamic T2*w MRI facilitated visualization of thrombin + Gd solution transiting through cerebral vasculature and persistent hyperintensities indicated occlusion. Area of trans-catheter perfusion dynamically quantified on representative slice before and after thrombin administration (22.20 ± 6.31 cm² vs. 13.28 ± 4.71 cm² respectively) indicated significantly reduced perfusion. ADC mapping showed evidence of ischemia as early as 27 min and follow-up T2w scans confirmed ischemic lesion (3.14 ± 1.41 cm²). Animals developed contralateral neurological deficits but were ambulatory. Our study has overcome long lasting challenge of inducing endovascular stroke model in pig. We were able to induce stroke using minimally invasive endovascular approach and observe in real-time formation of the thrombus, blockage of cerebral perfusion and eventually stroke lesion.

Intraarterial Versus Intravenous Tirofiban as an Adjunct to Endovascular Thrombectomy for Acute Ischemic Stroke

BACKGROUND AND PURPOSE

This study aimed to evaluate the treatment effect of intraarterial versus intravenous tirofiban during endovascular thrombectomy in acute ischemic stroke.

METHODS

This study retrospectively examined 503 patients with acute ischemic stroke with large vessel occlusion who received endovascular thrombectomy within 24 hours of stroke onset. Patients were divided into 3 groups: no tirofiban (n=354), intraarterial tirofiban (n=79), and intravenous tirofiban (n=70). The 3 groups were compared in terms of recanalization rate, symptomatic intracerebral hemorrhage, in-hospital death rate, 3-month death, and 3-month outcomes measured by modified Rankin Scale score (good clinical outcome of 0-2, poor outcome of 5-6). The comparison was statistically assessed by propensity score matching, followed by Freidman rank-sum test and pairwise Wilcoxon signed-rank test with Bonferroni correction.

RESULTS

The propensity score matching resulted in 92 matched triplets. Compared with the no-tirofiban group, the intravenous tirofiban group showed significantly increased recanalization (96.7% versus 64.1%, P<0.001), an increased rate of 3-month good outcome (69.5% versus 51.2%, P=0.034), and a lower rate of 3-month poor outcome (12.2% versus 41.4%, P<0.001). There was no significant difference between the tirofiban intravenous and no-tirofiban groups in terms of symptomatic intracerebral hemorrhage (2.2% versus 0%, P=1.000). However, symptomatic intracerebral hemorrhage was significantly increased in the intraarterial-tirofiban group compared with the no-tirofiban group (19.1% versus 0%, P<0.001), with an increased rate of in-hospital death (23.6% versus 0% P<0.001), and increased rate of 3-month death (26.8% versus 11.1%, P=0.021). The intraarterial-tirofiban and no-tirofiban group showed no significant difference in recanalization rate (66.3% versus 64.1%, P=1.000).

CONCLUSIONS

As an adjunct to endovascular thrombectomy, intravenous tirofiban is associated with high recanalization rate and good outcome, whereas intraarterial tirofiban is associated with high hemorrhagic rate and death rate.

Diagnosis and management of acute ischaemic stroke

Acute ischaemic stroke is a major public health priority and will become increasingly relevant to neurologists of the future. The cornerstone of effective stroke care continues to be timely reperfusion treatment. This requires early recognition of symptoms by the public and first responders, triage to an appropriate stroke centre and efficient assessment and investigation by the attending stroke team. The aim of treatment is to achieve recanalisation and reperfusion of the ischaemic penumbra with intravenous thrombolysis and/or endovascular thrombectomy in appropriately selected patients. All patients should be admitted directly to an acute stroke unit for close monitoring for early neurological deterioration and prevention of secondary complications. Prompt investigation of the mechanism of stroke allows patients to start appropriate secondary preventative treatment. Future objectives include improving accessibility to endovascular thrombectomy, using advanced imaging to extend therapeutic windows and developing neuroprotective agents to prevent secondary neuronal damage.

Altered Neural Networks in the Papez Circuit: Implications for Cognitive Dysfunction after Cerebral Ischemia

Cerebral ischemia remains a leading cause of mortality worldwide. Although the incidence of death has decreased over the years, surviving patients may suffer from long-term cognitive impairments and have an increased risk for dementia. Unfortunately, research aimed toward developing therapies that can improve cognitive outcomes following cerebral ischemia has proved difficult given the fact that little is known about the underlying processes involved. Nevertheless, mechanisms that disrupt neural network activity may provide valuable insight, since disturbances in both local and global networks in the brain have been associated with deficits in cognition. In this review, we suggest that abnormal neural dynamics within different brain networks may arise from disruptions in synaptic plasticity processes and circuitry after ischemia. This discussion primarily concerns disruptions in local network activity within the hippocampus and other extra-hippocampal components of the Papez circuit, given their role in memory processing. However, impaired synaptic plasticity processes and disruptions in structural and functional connections within the Papez circuit have important implications for alterations within the global network, as well. Although much work is required to establish this relationship, evidence thus far suggests there is a link. If pursued further, findings may lead toward a better understanding of how deficits in cognition arise, not only in cerebral ischemia, but in other neurological diseases as well.

From "Time is Brain" to "Imaging is Brain": A Paradigm Shift in the Management of Acute Ischemic Stroke

Arterial recanalization to restore the blood supply and limit the brain damage is the primary goal in the management of acute ischemic stroke (AIS). Since the publication of pivotal randomized clinical trials in 2015, endovascular thrombectomy has become part of the standard of care in selected cases of AIS from large-vessel occlusions up to 6 hours after the onset of symptoms. However, the association between endovascular reperfusion and improved functional outcome is not strictly time dependent. Rather than on rigid time windows, candidates should be selected based on vascular and physiologic information. This approach places imaging data at the center of treatment decisions. Advances in imaging-based management of AIS provide crucial information about vessel occlusion, infarct core, ischemic penumbra, and degree of collaterals. This information is invaluable in identifying patients who are likely to benefit from reperfusion therapies and excluding those who are unlikely to benefit or are at risk of adverse effects. The approach to reperfusion therapies continues to evolve, and imaging is acquiring a greater role in the diagnostic work-up and treatment decisions as shown in recent clinical trials with extended time window. The 2018 American Heart Association/American Stroke Association guidelines reflect a paradigm shift in the management of AIS from "Time is Brain" to "Imaging is Brain." This review discusses the essential role of multimodal imaging developing from recent trials on therapy for AIS.

Pathophysiological and clinical considerations in the perioperative care of patients with a previous ischaemic stroke: a multidisciplinary narrative review

With an ageing population and increasing incidence of cerebrovascular disease, an increasing number of patients presenting for routine and emergency surgery have a prior history of stroke. This presents a challenge for pre-, intra-, and postoperative management as the neurological risk is considerably higher. Evidence is lacking around anaesthetic practice for patients with vascular neurological vulnerability. Through understanding the pathophysiological changes that occur after stroke, insight into the susceptibilities of the cerebral vasculature to intrinsic and extrinsic factors can be developed. Increasing understanding of post-stroke systemic and cerebral haemodynamics has provided improved outcomes from stroke and more robust secondary prevention, although this knowledge has yet to be applied to our delivery of anaesthesia in those with prior stroke. This review describes the key pathophysiological and clinical considerations that inform clinicians providing perioperative care for patients with a prior diagnosis of stroke.

Thrombectomy and Thrombolysis of Isolated Posterior Cerebral Artery Occlusion

Background and Purpose—

We investigated efficacy and safety of acute revascularization with intravenous thrombolysis (IVT) and endovascular treatment (EVT) in ischemic stroke from isolated posterior cerebral artery occlusion, by assessing recanalization, disability, visual, cognitive outcomes, and hemorrhagic complications.

Methods—

For this retrospective single-center cohort study, we selected all consecutive patients with stroke with isolated posterior cerebral artery occlusion from the Acute Stroke Registry and Analysis of Lausanne registry between January 2003 and July 2018, and compared (1) IVT with conservative treatment (CTr) and (2) EVT to best medical therapy (BMT, ie, CTr or IVT) in terms of 3-month disability and visual field defect, and cognitive domains impaired after stroke. Unadjusted analysis, multivariable logistic regression, and propensity score matched analyses were performed.

Results—

Among 106 patients with isolated posterior cerebral artery occlusion, 21 received EVT (13 bridging), 34 IVT alone, and 51 CTr. Median age was 76 years, 47% were female and median National Institutes of Health Stroke Scale score was 7. Complete 24-hour recanalization was more frequent with IVT than CTr (51% versus 9%; OR [95% CI]=10.62 [2.13–52.92]) and with EVT compared with BMT (68% versus 34%; OR [95% CI]=4.11 [1.35–12.53]). Higher proportions of good disability, visual and cognitive outcomes were observed in IVT versus CTr, adj ORs (95% CI)=1.65 (0.60−4.52), 2.01 (0.58−7.01), 2.94 (0.35−24.4), respectively, and in EVT versus BMT, adj ORs (95% CI)=1.44 (0.51−4.10), 4.28 (1.00−18.29), 4.37 (0.72−26.53), respectively. Hemorrhagic complications and mortality did not increase with IVT or EVT.

Conclusion

s—We show increased odds of recanalization following IVT and even higher after EVT. We observed a trend for a positive effect on disability, visual, and cognitive outcomes with IVT over CTr and with EVT over BMT.

Biomimetic nanoparticle technology for cardiovascular disease detection and treatment

Cardiovascular disease (CVD), which encompasses a number of conditions that can affect the heart and blood vessels, presents a major challenge for modern-day healthcare. Nearly one in three people has some form of CVD, with many suffering from multiple or intertwined conditions that can ultimately lead to traumatic events such as a heart attack or stroke. While the knowledge obtained in the past century regarding the cardiovascular system has paved the way for the development of life-prolonging drugs and treatment modalities, CVD remains one of the leading causes of death in developed countries. More recently, researchers have explored the application of nanotechnology to improve upon current clinical paradigms for the management of CVD. Nanoscale delivery systems have many advantages, including the ability to target diseased sites, improve drug bioavailability, and carry various functional payloads. In this review, we cover the different ways in which nanoparticle technology can be applied towards CVD diagnostics and treatments. The development of novel biomimetic platforms with enhanced functionalities is discussed in detail.

Computational simulations of thrombolysis in acute stroke: Effect of clot size and location on recanalisation

Acute ischaemic stroke can be treated by intravenous thrombolysis whereby tissue plasminogen activator (tPA) is infused to dissolve clots that block blood supply to the brain. In this study, we aim to examine the influence of clot location and size on lysis pattern and recanalisation by using a recently developed computational modelling framework for thrombolysis under physiological flow conditions. An image-based patient-specific model is reconstructed which consists of the internal carotid bifurcation with the A1 segment of anterior cerebral arteries and M1 segment of middle cerebral arteries, and the M1 bifurcation containing the M2 segments. By varying the clot size and location, 7 scenarios are simulated mimicking thrombolysis of M1 and M2 occlusions. Our results show that initial breakthrough always occurs along the inner curvature of the occluded cerebral artery, due to prolonged tPA residence time in the recirculation zone. For a given occlusion site, lysis completion time appears to increase almost quadratically with the initial clot volume; whereas for a given clot volume, the simulated M2 occlusions take up to 30% longer for complete lysis compared to the corresponding M1 occlusions.

Stroke Patients' Status Post-Acute Phase of Illness. How Is It and How Ought It to Be: Ain Shams University Experience

BACKGROUND

Stroke is a leading cause of disability worldwide with a great impact on quality of life. Ain Shams University Hospital is a tertiary center for neurology and a pioneer in offering comprehensive stroke service in the region.

METHODS

A cross sectional study in which an 8 domains questionnaire was applied to all cerebrovascular stroke patients who were admitted to the stroke unit of the neurology department of Ain Shams University Hospital in the period from January 2016 till May 2017, with the aim to define pitfalls in post discharge.

RESULTS

From our study show that 20% of all patients discharged from acute stroke unit did not have further follow up with any stroke doctor. Moreover, 60% of patients were not seen by a physiotherapist after discharge, including almost half of patients with moderate or severe disability on discharge who are expected to have ongoing care needs. Patients who developed stroke complications were more likely to seek follow up. As expected, continuous follow up was associated with increased adherence to secondary preventive medications.

CONCLUSIONS

Patient needs should be assessed before patient discharge and patient and care givers should have clear written information on required follow up with stroke doctors, and arrangements made for receiving adequate rehabilitation post discharge.

Site of Occlusion May Influence Decision to Perform Thrombectomy Under General Anesthesia or Conscious Sedation

BACKGROUND

Although mechanical thrombectomy has become the standard of care for large-vessel occlusion, the role of conscious sedation versus general anesthesia (GA) with intubation during thrombectomy remains controversial. Aphasia may increase patient agitation or apparent uncooperativeness/confusion and thereby lead to higher use of GA. The purpose of this study was to identify risk factors for GA and determine if the side of vessel occlusion potentially impacts GA rates.

MATERIALS AND METHODS

Patients who underwent mechanical thrombectomy of the middle cerebral artery (MCA) for acute ischemic stroke at our institution between April 2014 and July 2017 were retrospectively reviewed. Patient characteristics, procedural factors, and outcomes were assessed using multivariate regression analyses. Mediation analysis was utilized to investigate whether aphasia lies on the causal pathway between left-sided MCA stroke and GA.

RESULTS

Overall, 112 patients were included: 62 with left-sided and 50 with right-sided MCA occlusion. Patients with left-sided MCA occlusion presented with aphasia significantly more often those with right-sided occlusion (90.3% vs. 32.0%; P<0.001). GA rates were significantly higher for patients with left-sided compared with right-sided MCA occlusion (45.2% vs. 20.0%; P=0.028). Aphasia mediated 91.3% of the effect of MCA stroke laterality on GA (P=0.02). GA was associated with increased door-to-groin-puncture time (106.4% increase; 95% confidence interval, 24.1%-243.4%; P=0.006) and adverse discharge outcome (odds ratio, 1.04; 95% confidence interval, 1.01-1.07; P=0.019).

CONCLUSIONS

Patients who had a stroke with left-sided MCA occlusion are more likely to undergo GA for mechanical thrombectomy than those with right-sided MCA occlusion. Aphasia may mediate this effect and understanding this relationship may decrease GA rates through modification of management protocols, potentially leading to improved clinical outcomes. Our study suggests that GA should preferentially be considered for the subset of patients with acute ischemic stroke undergoing mechanical thrombectomy for left-sided MCA occlusion.

Iodine-stained fragmented thromboembolism

AIM

Iodine-stained fragmented thromboembolism (ISFT) is a rare phenomenon encountered in the immediate aftermath of mechanical thrombectomy or rarely as a complication of post-carotid stenting. The aim was to describe the imaging appearance and discuss its pathophysiology.

METHOD

This is a retrospective review of patients who underwent mechanical thrombectomy for acute stroke at a single institution over the period of one year. All patients underwent the standard acute stroke imaging protocol (CT head, CT angiogram (CTA) and CT brain perfusion) and when clinically appropriate followed by catheter angiogram and mechanical thrombectomy. ISFT was defined as an arterial luminal filling defect with Hounsfield density equal to or greater than iodine seen on the biplanar CT or conventional CT. The presence and location of ISFT were documented. Standard CT angiogram (CTA) or magnetic resonance angiogram (MRA) was performed 24-48 hours after the neurointerventional procedure to assess for recanalization, volume of infarction and the fate of the ISFT.

RESULTS

ISFTs were identified in eight (five males and three females, age range 18-80 years) out of 49 patients in the following locations: distal M1 (n = 1), M2 (n = 4), M3 (n = 1), A1 (n = 1), distal A2 (n = 1). ISFT and vessel recanalization occurred in five patients on follow-up. ISFT and vessel occlusion persisted in two patients.

CONCLUSION

ISFT is likely the result of mechanical disruption of a thromboembolus, and porosity of the thromboembolus fragment may transiently retain iodinated contrast. Recognition of this entity may be important to aid detection of residual thromboembolism and avoid misinterpretation as calcified thromboembolism.

Call to hospital times for suspected stroke patients in the North East of England: a service evaluation

Introduction:

Stroke is a leading cause of mortality and morbidity. The role of the ambulance service in acute stroke care focuses on recognition followed by rapid transport to specialist care. The treatment options for acute ischaemic strokes are time dependent, so minimising the pre-hospital phase of care is important. The aim of this service evaluation was to report historical pre-hospital times for suspected stroke patients transported by the North East Ambulance Service NHS Foundation Trust (NEAS) and identify areas for improvement.

Methods:

This was a retrospective service evaluation using routinely collected data. Data on overall call to hospital times, call to arrival times, on scene times and leave scene to hospital are reported.

Results:

Data on 24,070 patients with an impression of stroke transported by NEAS between 1 April 2011 and 31 May 2018 are reported. The median call to hospital time increased from 41 to 68 minutes, call to arrival from 7 to 17 minutes, on scene from 20 to 30 minutes and leave to hospital from 12 to 15 minutes.

Conclusion:

The pre-hospital call to hospital time for stroke patients increased between 2011 and 2018. The call to arrival phase saw a sharp increase between 2015 and 2017, whereas on scene and leave scene to hospital saw steadier increases. Increasing demand on the ambulance service, reorganisation of regional stroke services and other factors may have contributed to the increase in times. Reducing the on scene phase of pre-hospital stroke care would lead to patient benefits and is the area where ambulance clinicians have the most influence.

Stroke in malignancy: complexities of diagnosis and management: a case report

BACKGROUND

Although there is an established association between cancer and stroke, the role of malignancy as a causative agent or comorbidity is not always clear. Moreover, there are no established guidelines on the acute treatment of cancer-associated stroke or optimal anticoagulation. This case report illustrates the significance of these practice gaps.

CASE PRESENTATION

A 62-year-old Caucasian woman presented to our institute with acute neurological deficits and was found to have an occluded left middle cerebral artery on a computed tomographic angiogram. She was administered intravenous alteplase and underwent unsuccessful endovascular clot retrieval. Besides smoking and her age, she had no cerebrovascular risk factors, and the results of baseline investigations for the cause of stroke were negative. Subsequent computed tomography of the chest, abdomen, and pelvis showed metastatic malignancy, and in the context of a significantly elevated serum cancer antigen 19-9, we suspected a pancreatic primary cancer. A transthoracic echocardiogram demonstrated mitral regurgitation but no visible vegetation. The patient died of her illness. We made a diagnosis of cancer-associated stroke, specifically a likely case of nonbacterial thrombotic endocarditis.

CONCLUSIONS

This case highlights the importance of having a high threshold of suspicion for malignancy as a cause of stroke.

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.

Mechanical thrombectomy for the treatment of acute ischaemic stroke following pulmonary lobectomy

Acute ischaemic stroke is a devastating postoperative complication that significantly impacts upon a patient's quality of life. Endovascular retrieval of thromboembolic material from proximal cerebral arteries by mechanical thrombectomy is the new standard of care for patients presenting with a proximal artery occlusion. We report the case of a patient developing an acute ischaemic stroke following pulmonary lobectomy, who was transferred to the regional neurosciences unit, despite the absence of an established referral pathway, to undergo mechanical thrombectomy, with significant prognostic neurological benefit. We would advocate all cardiothoracic centres identify their regional neurosciences unit and initiate discussion to establish a referral pathway.

How should we treat patients who wake up with a stroke? A review of recent advances in management of acute ischemic stroke

Acute ischemic strokes account for 85% of all strokes and are the fifth leading cause of mortality in the United States. About one in five of all ischemic strokes occur during sleep and are not noticed until the patient wakes up with neurological deficits. There is growing evidence to support that a significantly higher number of stroke patients could benefit from more aggressive care, especially those patients who wake up with strokes. There is increasing research to support a physiologically-based approach based on advanced imaging rather than simply a time-based determination of whether or not a patient would benefit from reperfusion. Advanced imaging such as CT-Perfusion and MR DWI-FLAIR can be used to establish the age of the lesion and determine the extent of the brain tissue that is salvageable. If physicians could identify those patients with wake-up strokes that are candidates for intervention, there may be opportunity to treat 3 million more people, reducing long term disability and healthcare expenditures. Patients who are in the window for IV rtPA should receive it as soon as possible as well as be evaluated for mechanical thrombectomy. For those who are out of the window for IV rtPA, consider further imaging such as CTP and MR brain for diffusion-weighted sequences to evaluate for potential endovascular intervention. If a large vessel occlusion is present and imaging demonstrates a small infarct core and a large area of salvageable tissue, mechanical thrombectomy may be beneficial for the best possible functional outcome.

Self-assembling injectable peptide hydrogels for emerging treatment of ischemic stroke

Ischaemic stroke remains one of the leading causes of death and disability worldwide, without any long-term effective treatments targeted at regeneration. This has led to developments of novel, biomaterial-based strategies using self-assembling peptide hydrogels.