Extended Time Window (>6 Hour) Mechanical Thrombectomy; Good Clinical Outcome in the Younger Age Population in Thrombectomy Cases: Relationship between Age and Prognosis

BACKGROUND

Mechanical thrombectomy (MT) has become increasingly common in recent years, as studies have shown that it can be an effective treatment for acute ischemic stroke (AIS) caused by large vessel occlusion (LVO). However, the efficacy of MT in the extended time window (6 to 24 h) is still uncertain. Our study aims to evaluate the outcomes of MT in the extended time window for AIS patients.

METHODS

We reviewed data on AIS patients who received MT beyond six hours of stroke onset from 2015 to 2022. The patients' occlusions were in the internal carotid artery (ICA), middle cerebral artery (MCA), or posterior circulation. Our evaluation included the modified Rankin scale (mRS) and 90-day mortality rates, as well as complications, such as symptomatic intracranial hemorrhage (sICH).

RESULTS

Thirty-one patients were included in this study, with a mean age of 75.6 ± 15.1 years, of whom 54.8% were male. The median NIHSS score at presentation was 17. Successful recanalization (TICI 2b to 3) was achieved in 90.3% of patients and the rate of sICH was 6.4%. No difference was observed between the two age groups. The younger age group (<80 years old) showed a better clinical outcome (mRS 0-2; p < 0.05, Fisher's exact test) compared with the older age group. The overall mortality rate was 6.4%.

CONCLUSION

Our study shows that (MT) can be performed effectively and safely within an extended time window, resulting in satisfactory functional outcomes, particularly in the younger age group.

Decreased miR-146a expression in acute ischemic stroke directly targets the Fbxl10 mRNA and is involved in modulating apoptosis

BACKGROUND

miR-146a, a strong pro-apoptotic factor in some pathophysiological processes, is reported to be involved in ischemic stroke (IS), though its role remains unclear. Fbxl10 is an active anti-apoptotic factor and a predicted target of miR-146a. We hypothesized that dysregulation of miR-146a contributes to ischemic injury by targeting Fbxl10.

METHODS

Circulating miRNAs were detected by miRNA microarray and qRT-PCR. miR-146a targets were predicted using bioinformatics and confirmed with a dual luciferase reporter assay. We used an in vitro ischemic model of oxygen-glucose deprivation and reperfusion (OGD/R) to mimic cerebral ischemia/reperfusion (I/R) conditions. Expression of miR-146a, Fbxl10 and Bcl2l2 mRNAs, and Fbxl10 and Bcl2l2 proteins was verified by qRT-PCR and Western blotting. The effects of miR-146a on neuronal cell apoptosis were evaluated by flow cytometry.

RESULTS

A significant reduction in miR-146a expression was observed in acute ischemic stroke (AIS). A dual-luciferase reporter assay showed that Fbxl10, but not Bcl2l2, is a target of miR-146a. Transfection with miR-146a mimics promoted apoptosis in SK-N-SH cells and significantly reduced expression of Fbxl10. Conversely, miR-146a inhibition attenuated OGD/R-induced neuronal cell death and significantly up-regulated Fbxl10 expression.

CONCLUSIONS

miR-146a expression was significantly down-regulated in AIS, and Fbxl10 was identified as a target of miR-146a. Moreover, up-regulation of Fbxl10, a miR-146a target, likely protects neurons from ischemic death.

State-of-the-art endovascular treatment of acute ischemic stroke

Stroke is the third leading cause of death in the USA. An estimated 795,000 new or recurrent stroke events occur annually, mostly ischemic in nature. Arterial recanalization and subsequent reperfusion performed shortly after symptom onset can help to restore brain function in acute ischemic stroke (AIS). The only treatment currently approved by the United States Food and Drug Administration is intravenous tissue plasminogen activator, administered within 4.5 h of symptom onset. However, this short window often precludes effective intervention. Mechanical neurothrombectomy devices offer many potential advantages over pharmacologic thrombolysis, including more rapid achievement of recanalization, enhanced efficacy in treating large-vessel occlusions, and a potentially lower risk of hemorrhagic events. The goal of this chapter is to describe the state-of-the-art neurothrombectomy devices and stenting techniques for endovascular treatment of acute ischemic stroke, as well as to highlight recent advances in reperfusion therapies. Ongoing clinical trials, some with randomized, controlled designs, are included.

Successful mechanical thrombectomy in a 2-year-old male through a 4-French guide catheter

A 2-year-old boy with hypoplastic left heart syndrome that required multiple cardiovascular surgeries and a heterozygous prothrombin G20210A mutation with resulting thrombophilia maintained on warfarin presented with acute right middle cerebral artery (MCA) infarction manifesting as a left hemiplegia. An MRI revealed a complete occlusion of the right M1 segment with an area of restricted diffusion in the right basal ganglia representing only a small area of acute infarction. Patchy areas of subacute infarction were also present in the right MCA territory. He underwent endovascular mechanical thrombectomy with a stent retriever. This is an account of a successful mechanical thrombectomy performed in the youngest patient reported in the English literature to date.

Thrombectomy in patients with large cerebral artery occlusion: a single-center experience with a new stent retriever

INTRODUCTION

The Trevo device, a new stent retriever, may be utilized in patients with large cerebral artery occlusion.

METHODS

Fifty patients with large cerebral artery occlusion and treated with the Trevo device were analyzed. Patients may have received intravenous thrombolysis as a bridging concept in addition to thrombectomy. Outcome and recanalization parameters were documented using the National Institutes of Health Scale, the modified Ranking Scale (mRS) and Thrombolysis in Cerebral Infarction (TICI) score.

RESULTS

In all, 82% (95% confidence interval [CI]: 69%-91%) were documented with TICI 2b and 3. Good clinical outcome after 90 days (mRS ≤ 2) was assessed in 61% (95% CI: 46%-75%). Symptomatic intracerebral hemorrhage occurred in 6 patients (12%, 95% CI: 1%-17%). The overall mortality rate was 14% (95% CI: 6%-27%).

CONCLUSION

Thrombectomy with the new stent retriever device is feasible and effective and has an acceptable risk of intra-cerebral hemorrhage even in combination with pharmacological revascularization techniques.

Acute carotid artery dissection treated with stenting and hematoma aspiration guided by ultrasonography

We report the successful treatment of dissection with stenosis of the carotid artery by stenting and aspiration of hematoma. A male patient, presenting with acute blurred vision and weakness and numbness of the right side of his body, was diagnosed with common carotid artery (CCA) dissection and severe stenosis of the internal carotid artery and CCA by digital subtraction arteriography and color Doppler ultrasonography (CDU). Two stents were separately implanted into the left internal carotid artery and CCA to restore blood flow and seal the opening of the dissection. The hematoma inside the CCA dissection was transcutaneously aspirated under CDU guidance after thrombolysis with tissue plasminogen activator. Three days after the operation, the dissection was still sealed. The patient was discharged 1 week later without any signs or symptoms. Follow-up examination at 70 days confirmed complete healing of the CCA dissection. Transcutaneous intradissection hematoma aspiration with CDU guidance may be applicable in treating arterial dissection, especially when conservative treatments cannot be expected to improve severe flow disturbances.

Comparison of Endovascular Treatment Versus Conservative Medical Treatment in Patients With Acute Basilar Artery Occlusion

Introduction:

Basilar artery occlusion (BAO) causes mortality up to 90%.

Methods:

A total of 99 patients with BAO received either endovascular (endovascular mechanical recanalization and/or intra-arterial with optional intravenous thrombolysis [IVT] as bridging concept) or conservative medical treatment (IVT and/or medical oral therapy). Outcome parameters were measured in accordance with the thrombolysis in cerebral infarction (TICI), National Institutes of Health Stroke Scale (NIHSS), and modified Rankin Scale (mRS) scores.

Results:

In all, 78% underwent endovascular and 22% conservative medical treatment. The NIHSS at admission was 20 in both the groups. Postprocedurally, 36% (95% confidence interval: 26%-48%) of the endovascular group and 9% (21%-64%) of the conservative group reached TICI 3 ( P = .017). In all, 30% of the endovascular group and 9% of the conservative group were documented with TICI 2b ( P = .057). At 90 days follow-up, 45% (31%-60%) of the endovascular-treated patientsand no patient (0%-25%) of the conservative-treated group reached mRS ≤2 ( P = .012).

Conclusion:

Endovascular treatment of BAO provides a better chance to survive this severe condition with good clinical outcome.

Comparison of stent-retriever devices versus the Merci retriever for endovascular treatment of acute stroke

BACKGROUND AND PURPOSE

Revascularization of large cerebral artery occlusion is the therapeutic goal in stroke therapy. Currently, many recanalization devices are in clinical use. This study compares the outcome parameters, efficacy, and safety of the new generation of stent-retriever devices with the well-established Merci retriever.

MATERIALS AND METHODS

All patients who received endovascular mechanical recanalization therapy were prospectively registered. One hundred twenty-two patients were treated with either new stent retrievers, including the Trevo and Solitaire devices, or the Merci retriever system. Recanalization of the occluded vessel was assessed in accordance with the modified TICI score, and outcome parameters, including the NIHSS and mRS scores, were documented. Clinical status was recorded after neurointervention, at time of discharge, and after 90 days.

RESULTS

The mean age of all patients was 68 years; 54% were male, with no statistical differences in demographics between both groups. Successful recanalization (TICI 3 and TICI 2b) was achieved in 82% of patients treated with stent retrievers compared with 62% of patients treated with Merci retrievers (P = .016). In the 90-day follow-up, 65% of patients treated with stent retrievers and 35% of those treated with the Merci had achieved a good (mRS = 0-2) clinical outcome (P = .002). Patients treated with stent retrievers had a significantly shorter treatment time (72 versus 122 minutes, P < .01) and less severe intracerebral hemorrhages (10% versus 28%, P < .01).

CONCLUSIONS

Patients treated with Trevo and Solitaire stents had a better revascularization rate, better clinical outcome, and lower complication rate than patients treated with the Merci retriever.

Higher degrees of recanalization after mechanical thrombectomy for acute stroke are associated with improved outcome and decreased mortality: pooled analysis of the MERCI and Multi MERCI trials

BACKGROUND AND PURPOSE

Although the combined end point of partial and complete recanalization is a well-established predictor of good outcome following acute stroke intervention, few investigations have evaluated the effect of the degree of recanalization. We hypothesized that greater degrees of recanalization would be associated with a higher likelihood of favorable functional outcomes.

MATERIALS AND METHODS

Data from MERCI and Multi MERCI-prospective single-arm trials of endovascular mechanical thrombectomy for acute stroke-were pooled. The TIMI score was used to define the degree of recanalization, and a favorable outcome was defined as an mRS score of 0-2 at 90 days.

RESULTS

A total of 305 patients were included. Age, stroke severity, and site of arterial occlusion did not differ among groups stratified by the TIMI score. The unadjusted OR for a favorable outcome increased significantly as the TIMI score increased from 0 to 1 (OR, 5.9; 95% CI, 1.7-20.0; P = .007) and from 2 to 3 (OR. 2.3; 95% CI, 1.2-4.5; P = .01) and the likelihood of death decreased significantly as the TIMI score increased from 2 to 3 (OR, 2.2; 95% CI, 1.1-4.3; P = .05). In multivariate analysis, each increase in TIMI grade increased the odds of a good outcome 2.6-fold (95% CI, 1.9-3.4, P < .0001).

CONCLUSIONS

Increases in the TIMI score were highly associated with improved outcomes. This finding not only provides additional evidence that restoration of blood flow improves clinical outcomes in ischemic stroke but also suggests that interventionalists should strive for complete revascularization when they provide endovascular treatment for acute ischemic stroke.

MicroRNA-21 protects neurons from ischemic death

MicroRNAs are small RNAs that attenuate protein expression by complementary binding to the 3'-UTR of a target mRNA. Currently, very little is known about microRNAs after cerebral ischemia. In particular, microRNA-21 (miR-21) is a strong antiapoptotic factor in some biological systems. We investigated the role of miR-21 after stroke in the rat. We employed in situ hybridization and laser capture microdissection in combination with real-time RT-PCR to investigate the expression of miR-21 after stroke. In situ hybridization revealed that miR-21 expression was upregulated in neurons of the ischemic boundary zone, and quantitative real-time RT-PCR analysis revealed that stroke increased mature miR-21 levels by approximately threefold in neurons isolated from the ischemic boundary zone by laser capture microdissection as compared with homologous contralateral neurons 2 days (n = 4; P < 0.05) and 7 days (n = 3; P < 0.05) after stroke. In vitro, overexpression of miR-21 in cultured cortical neurons substantially suppressed oxygen and glucose deprivation-induced apoptotic cell death, whereas attenuation of endogenous miR-21 by antisense inhibition exacerbated cell death after oxygen and glucose deprivation. Moreover, overexpression of miR-21 in neurons significantly reduced FASLG levels, and introduction of an miR-21 mimic into 293-HEK cells substantially reduced luciferase activity in a reporter system containing the 3'-UTR of Faslg. Our data indicate that overexpression of miR-21 protects against ischemic neuronal death, and that downregulation of FASLG, a tumor necrosis factor-α family member and an important cell death-inducing ligand whose gene is targeted by miR-21, probably mediates the neuroprotective effect. These novel findings suggest that miR-21 may be an attractive therapeutic molecule for treatment of stroke.