Clinical outcome prediction after thrombectomy of proximal middle cerebral artery occlusions by the appearance of lenticulostriate arteries on magnetic resonance angiography: A retrospective analysis

Association of Morphology of Lenticulostriate Arteries and Proximal Plaque Characteristics With Single Subcortical Infarction: A Whole-Brain High-Resolution Vessel Wall Imaging Study

BACKGROUND

We aimed to investigate the association of characteristics of lenticulostriate artery (LSA) morphology and parental atheromatous disease (PAD) with single subcortical infarction (SSI) and to explore whether the LSA morphology is correlated with proximal plaque features in asymptomatic PAD.

METHODS AND RESULTS

Patients with acute SSI were prospectively enrolled and classified as large- and small-SSI groups. The clinical data and imaging features of LSA morphology (branches, length, dilation, and tortuosity) and middle cerebral artery plaques (normalized wall index, remodeling index, enhancement degree, and hyperintense plaques) were evaluated. Logistic regression was performed to determine the association of large SSIs with morphologic features of LSAs and plaques. The Spearman correlation between the morphologic characteristics of LSAs and plaque features in asymptomatic PAD was analyzed. Of the 121 patients recruited with symptomatic PAD, 102 had coexisting asymptomatic contralateral PAD. The mean length of LSAs (odds ratio, 0.84 [95% CI, 0.73-0.95]; P=0.007), mean tortuosity of LSAs (odds ratio, 1.13 [95% CI, 1.05-1.22]; P=0.002), dilated LSAs (odds ratio, 22.59 [95% CI, 2.46-207.74]; P=0.006), and normalized wall index (odds ratio, 1.08 [95% CI, 1.01-1.15]; P=0.022) were significantly associated with large SSIs. Moreover, the normalized wall index was negatively correlated with the mean length of LSAs (r=-0.348, P<0.001), and the remodeling index was negatively correlated with the mean tortuosity of LSAs (r=-0.348, P<0.001) in asymptomatic PAD.

CONCLUSIONS

Our findings suggest that mean length of LSAs, mean tortuosity of LSAs, dilated LSAs, and normalized wall index are associated with large SSIs. Moreover, plaque features in asymptomatic PAD are correlated with morphologic features of LSAs.

Delayed CTP-Derived Deep Venous Outflow: A Novel Predictor of Striatocapsular Infarction after M1 Thrombectomy

BACKGROUND AND PURPOSE

Isolated striatocapsular infarction occurs commonly in patients with ischemic stroke following M1 thrombectomy. We aimed to explore the correlation between CTP-derived parameters of deep venous outflow at presentation and subsequent striatocapsular infarction in a retrospective cohort of such patients.

MATERIALS AND METHODS

TTP and peak enhancement were measured on CTP-derived time-attenuation curves of the internal cerebral and thalamostriate veins bilaterally. The difference in TTP (ΔTTP) and the relative decrease in venous enhancement between the ischemic and normal sides were calculated. NCCT performed 24 (SD, 12) hours postthrombectomy was used to determine tissue fate in the caudate head, caudate body, lentiform nucleus, and internal capsule. Striatocapsular ischemia (striatocapsular infarction-positive) was defined as infarction and striatocapsular injury as either infarction, contrast enhancement, or hemorrhagic transformation in ≥1 of these regions. A striatocapsular ischemia score was calculated (0 = no ischemic region, 1 = 1 ischemic region, 2 = ≥2 ischemic regions).

RESULTS

One hundred sixteen patients were included in the analysis. Sixty-one patients had striatocapsular infarction (striatocapsular infarction-positive). The mean thalamostriate ΔTTP was 1.95 (SD, 1.9) seconds for patients positive for striatocapsular infarction and 0.79 (SD, 2.1) for patients negative for it (P = .010). Results were similar for striatocapsular injury. The mean thalamostriate ΔTTP was 0.79 (SD, 2.1), 1.68 (SD, 1.4), and 2.05 (SD, 2) for striatocapsular infarction scores of 0, 1, and 2, respectively (P = .030).

CONCLUSIONS

CTP-derived thalamostriate ΔTTP is an excellent surrogate marker for striatocapsular infarction in patients post-M1 thrombectomy. The novel approach of extracting venous outflow parameters from CTP has numerous potential applications and should be further explored.

Mechanical Thrombectomy for M1 Subocclusive Thrombus With Lateral Lenticulostriate Artery Occlusion: A Case Report and Literature Review

The treatment for middle cerebral artery subocclusive thrombi is not standardized. Here, we report a case of M1 subocclusive thrombus with lateral lenticulostriate artery occlusion that was successfully treated with mechanical thrombectomy. This article describes a treatment strategy for M1 subocclusive thrombus, focusing on the indications for mechanical thrombectomy. A 58-year-old male on admission for pneumonia had a sudden onset of dysarthria and motor deficits. He has a history of dilated cardiomyopathy and underwent left ventricular assist device implantation 3 years ago. At onset, his National Institutes of Health Stroke Scale (NIHSS) score was nine. Computed tomography angiography demonstrated a filling defect in the distal right M1 segment of the middle cerebral artery. Angiography confirmed the presence of a subocclusive thrombus within the distal right M1 segment, although peripheral blood flow was maintained. Mechanical thrombectomy was performed for the M1 subocclusive thrombus using a direct aspiration first-pass technique, resulting in successful aspiration of the thrombus on the first pass. After the procedure, recanalization of the lateral lenticulostriate artery was detected, and the patient demonstrated full recovery (NIHSS score 0). Mechanical thrombectomy can be considered as a treatment option in cases of acute ischemic stroke caused by M1 subocclusive thrombus with lateral lenticulostriate artery occlusion, which presents with a high NIHSS score or neurological deterioration.

EphrinB2-EphB2 signaling for dendrite protection after neuronal ischemia in vivo and oxygen-glucose deprivation in vitro

In order to rescue neuronal function, neuroprotection should be required not only for the neuron soma but also the dendrites. Here, we propose the hypothesis that ephrin-B2-EphB2 signaling may be involved in dendritic degeneration after ischemic injury. A mouse model of focal cerebral ischemia with middle cerebral artery occlusion (MCAO) method was used for EphB2 signaling test in vivo. Primary cortical neuron culture and oxygen-glucose deprivation were used to assess EphB2 signaling in vitro. siRNA and soluble ephrin-B2 ectodomain were used to block ephrin-B2-Ephb2 signaling. In the mouse model of focal cerebral ischemia and in neurons subjected to oxygen-glucose deprivation, clustering of ephrin-B2 with its receptor EphB2 was detected. Phosphorylation of EphB2 suggested activation of this signaling pathway. RNA silencing of EphB2 prevented neuronal death and preserved dendritic length. To assess therapeutic potential, we compared the soluble EphB2 ectodomain with the NMDA antagonist MK801 in neurons after oxygen-glucose deprivation. Both agents equally reduced lactate dehydrogenase release as a general marker of neurotoxicity. However, only soluble EphB2 ectodomain protected the dendrites. These findings provide a proof of concept that ephrin-B2-EphB2 signaling may represent a novel therapeutic target to protect both the neuron soma as well as dendrites against ischemic injury.

Angiographic early hyperemia in the middle cerebral artery territory after thrombectomy is associated with favorable clinical outcome in anterior circulation stroke

OBJECTIVES

Angiographic cortical early hyperemia (EH) is frequently observed after endovascular thrombectomy (EVT) for large vessel occlusion (LVO) stroke. The aim of the study is to investigate the relationship between EH and clinical outcomes.

METHODS

Between January 2015 and September 2018, consecutive patients who underwent EVT for anterior circulation LVO stroke with optimal recanalization (modified thrombolysis in cerebral infarction 2b or 3) were included. Angiographic studies after immediate reperfusion were used for analysis for cortical EH sign. Clinical functional outcomes were evaluated with the modified Rankin Scale (mRS) at 90 days. Safety outcomes, including mortality and intracerebral hemorrhage, were assessed. The association of EH between clinical functional and safety outcomes was analyzed.

RESULTS

A total of 143 patients were analyzed (mean age: 71 years; median National Institutes of Health Stroke Scale score: 18). A positive EH sign was observed in 88 (62%) patients. Good functional outcome at 90 days was significantly different between the EH⁺ and EH^- groups (p = .0157). Intracerebral hemorrhage and mortality did not differ between groups. In multivariate logistic regression analysis, EH was an independent predictor for good clinical outcome (mRS ≤ 2, odds ratio: 3.49, p = .0034) in addition to young age.

CONCLUSION

Results revealed that the presence of EH is associated with better clinical outcome at 90 days, but not associated with increased hemorrhagic complication. These findings with clinically relevant implications require further validation.

KEY POINTS

• Angiographic cortical hyperemia is a common finding immediately after endovascular thrombectomy. • Presence of cortical hyperemia is an independent prognostic factor for good clinical outcome. • Hemorrhagic complication is not associated with cortical hyperemia.

Biomechanics and hemodynamics of stent-retrievers

In 2015, multiple randomized clinical trials showed an unparalleled treatment benefit of stent-retriever thrombectomy as compared to standard medical therapy for the treatment of a large artery occlusion causing acute ischemic stroke. A short time later, the HERMES collaborators presented the patient-level pooled analysis of five randomized clinical trials, establishing class 1, level of evidence A for stent-retriever thrombectomy, in combination with intravenous thrombolysis when indicated to treat ischemic stroke. In the years following, evidence continues to mount for expanded use of this therapy for a broader category of patients. The enabling technology that changed the tide to support endovascular treatment of acute ischemic stroke is the stent-retriever. This review summarizes the history of intra-arterial treatment of stroke, introduces the biomechanics of embolus extraction with stent-retrievers, describes technical aspects of the intervention, provides a description of hemodynamic implications of stent-retriever embolectomy, and proposes future directions for a more comprehensive, multi-modal endovascular approach for the treatment of acute ischemic stroke.

Endovascular treatment or general treatment: how should acute ischemic stroke patients choose to benefit from them the most?: A systematic review and meta-analysis

BACKGROUND

Acute ischemic stroke due to large-vessel occlusion is a leading cause of death and disability, and therapeutic time window was limited to 4.5 hour when treated with intravenous thrombolysis. It has been acknowledged that endovascular treatment (EVT) is superior to general treatment (only medication, including intravenous recombinant tissue plasminogen activator (rt-PA)) in improving the outcome of AIS since 2015. However, the benefits were limited to improvement of functional outcomes and functional independence. Hence, this meta-analysis was conducted to summarize the benefits of EVT for acute ischemic stroke, explore underlying indications of EVT for AIS patients and suggest implications for clinical practice and future research.

METHODS

A search was performed to identify eligible studies in PubMed, Scopus and Web of Science updated to February 5, 2019. Functional outcomes, the modified Rankin Scale (mRS) 0-1, mRS 0-2, all-cause mortality, symptomatic intracerebral hemorrhage and asymptomatic intracerebral hemorrhage (aICH) at 90 days were selected as outcomes. Data was pooled to calculate the odds ratio (OR) and 95% confidence interval (CI). Heterogeneity, subgroup analysis, sensitivity analysis and publication bias were also performed in this meta-analysis.

RESULTS

Eighteen studies comprising 3831 patients were included and analyzed in this meta-analysis. In comparison with general treatment, improved functional outcomes (mRS 0-1: OR = 1.68, 95% CI = 1.43-1.97, inconsistency index [I = 57%, P < .00001; mRS 0-2: OR = 1.78, 95% CI = 1.55-2.03, I = 69%, P < .00001), reduced risk of all-cause mortality (OR = 0.82, 95% CI = 0.70-0.98, I = 27%, P = .03) but higher risk of aICH (OR = 1.43, 95% CI = 1.05-1.95, I = 0%, P = .02) at 90 days were found in AIS patients treated with EVT. Age < 70, National Institutes of Health Stroke Scale ≥20 and maximum delay for invention>5 hours could improve clinical outcomes following EVT. In sensitivity analysis, it showed that 2 studies had a great influence on the pooled ORs. No potential publication bias was found in this meta-analysis.

CONCLUSION

Taken together, EVT, which led to improved functional outcomes and decreased risk of death, is superior to general treatment for AIS patients with age < 70, National Institutes of Health Stroke Scale ≥20 and maximum delay for invention>5 hours. Moreover, it suggests that "with mechanical thrombectomy" is potential favorable factor for improving aICH in comparison with general treatment.

Lenticulostriate arteries appearance before thrombectomy predicts good outcome in acute middle cerebral artery occlusion

Background

Endovascular therapy is widely used in acute large vessel occlusion. This study investigated whether imaging of lateral lenticulostriate arteries (LSAs) before thrombectomy would potentially be helpful for predicting prognosis of patients with acute M1 segment of middle cerebral artery occlusion (MCAO).

Methods

59 consecutive patients with acute M1 segment of MCAO treated with mechanical thrombectomy at two comprehensive stroke centers were analyzed. Patients were categorized into LSA+ (appearing of lateral LSAs) and LSA- (sparing of lateral LSAs) group according to preprocedural digital substraction angiography (DSA). Baseline data and clinical outcomes were compared. A good clinical outcome was defined as a modified Rankin Scale score of 0 to 2 at 3 months. The association between clinical and imaging parameters and functional outcome was evaluated with logistic regression analysis.

Results

LSA+ was shown in 36 patients (61%). LSA+ group had a significantly higher proportion of good outcome (72.2% vs. 8.7%, OR 27.3,95% CI 5.38–138.4, P < 0.001), lower risk of symptomatic intracranial haemorrhages (sICH) (8.3% vs. 47.8%,OR 0.10,95% CI 0.02–0.42, P = 0.001) and lower mortality in hospital (5.6% vs. 34.8%, OR 0.11,95% CI 0.02–0.58, P < 0.004) compared with LSA- group. Patients in LSA+ group had lower baseline NIHSS score(P < 0.01) and NIHSS score at 14 days(P < 0.01) and smaller infarct core volume (P = 0.016) on computed tomography perfusion imaging (CTP) compared to the LSA- group. Multivariate logistic regression analysis showed that a small infarct core volume (OR 6.74,95% CI 1.148–39.569, P = 0.035) and LSA+(OR 22.114,95% CI 3.339–146.470, P = 0.001) were associated with a good clinical outcome.

Conclusions

Our data suggest that appearance of lateral LSAs before mechanical thrombectomy would be potentially helpful for predicting favorable prognosis of patients with acute M1 segment of MCAO.

Endovascular thrombectomy versus medical treatment for large vessel occlusion stroke with mild symptoms: A meta-analysis

It remains controversial as to whether mechanical thrombectomy (MT) is safer and more beneficial in patients with large vessel occlusion stroke (LVOS) presenting with a National Institutes of Health Stroke Scale score ≤ 8. We therefore conducted a meta-analysis of the published data.We searched PubMed and Embase and pooled relevant data in the meta-analyses using fixed effects models. Only studies that directly compared best medical therapy alone (BMT) with MT were included. We used odds ratios to analyze the associations between MT and 90-day functional outcome (evaluated using the modified Rankin Scale (mRS)), mortality, and rates of symptomatic intracerebral hemorrhage (sICH) in patients with LVOS and minor symptoms. Five studies including a total of 581 patients met our inclusion criteria. A significant difference was found that the patients treated with MT were associated with improved 90-day mRS score (OR, 1.68; 95% CI, 1.08-2.61) compared with BMT group. There was no difference in 90-day mortality between the two groups. However, sICH occurred more frequently in the MT group than the BMT group (OR, 3.89; 95% CI, 1.83-8.27). Patients with LVOS with minor or mild symptoms who underwent primary thrombectomy had a significantly improved 90-day mRS score compared to those who received BMT alone. Meanwhile, the risk of sICH was higher in the MT group than that in BMT group. Future randomized clinical controlled trials evaluating the role of endovascular reperfusion for LVOS with minimal symptoms are warranted.