Expanding the treatment window with mechanical thrombectomy in acute ischemic stroke

Introduction Acute ischemic stroke is a common disease associated with high mortality and significant long-term disability. Treatment options for acute ischemic stroke continue to evolve and include pharmaceutical and mechanical therapies. With the recent US Food and Drug Administration approval of a new device for mechanical thrombectomy, the options available for treatment of acute ischemic stroke have been expanded. Thrombolytic therapy is generally given intravenously in the first 3 h and up to 6 h via the intraarterial route for pharmacological clot disruption. The maximum time-frame for mechanical thrombectomy devices has yet to be determined.Methods A 78-year-old female presented to the emergency room with a dense right hemiparesis, leftward gaze preference and dense global aphasia. Eight hours after symptom onset, left carotid angiography confirmed a left internal carotid artery terminus occlusion. A single pass was made through the clot with an X6 Merci Retriever device.Results After a single pass, the vessel was reopened and normal flow in the left internal carotid artery was demonstrated. At the time of discharge, her neurological deficits had improved significantly. Furthermore, the final infarct area, as demonstrated on magnetic resonance imaging, was probably much smaller than it would have been if the vessel had not been recanalized.Conclusion We report the use of a new mechanical thrombectomy device 8 h after onset of ischemic symptoms, with substantial subsequent improvement in neurological outcome. In selected cases, use of the Merci Retriever can result in improved outcomes beyond the traditional 6-hwindow used for intraarterial pharmacological thrombolysis.     

A dedicated animal model for mechanical thrombectomy in acute stroke

BACKGROUND: Recent studies have focused on mechanical thrombectomy as a means to reduce the time required for revascularization and increase the revascularization rate in acute stroke. To date no systematic evaluation has been made of the different mechanical devices in this novel and fast-developing field of endovascular interventions. To facilitate such evaluations, we developed a specific in vivo model for mechanical thrombectomy that allows visualization of dislocation or fragmentation of the thrombus during angiographic manipulation. METHODS: Angiography and embolization with a preformed thrombus was performed in 8 swine. The thrombus was generated by mixing 25 IU bovine thrombin and 10 mL autologous blood. For visualization during angiography, 1 g barium sulfate was added. RESULTS: The preformed thrombus exhibited mechanical stability, reproducibility, and high radiographic absorption, providing excellent visibility during angiography. The setting allowed selective embolization of targeted vessels without thrombus fragmentation. Despite the application of barium sulfate no local or systemic reaction occurred. Histologic evaluation revealed no intimal damage caused by the thrombus or contrast agent washout. CONCLUSION: The model presented here allows selective and reliable thromboembolization of vessels that reproduce the anatomic and hemodynamic situation in acute cerebrovascular stroke. It permits visualization of the thrombus during angiography and intervention, providing unique insight into the behavior of both thrombus and device, which is potentially useful in the development and evaluation of mechanical clot retrieval in acute cerebrovascular stroke.     

急性脑梗死机械取栓后引流静脉早显与脑出血转化的关系

目的探讨急性脑梗死机械取栓术后血管造影显示引流静脉早显(EVF)与脑出血转化(HT)的关系。方法回顾性分析2015年1月至2018年11月,扬州大学附属医院经机械取栓的急性前循环大血管闭塞患者的影像及人口统计资料、血管危险因素及其他临床资料。参照欧洲协作急性卒中研究Ⅱ(ECASSⅡ),对机械取栓术后HT进行改良分型(HT阴性、HT-Ⅰ型和HT-Ⅱ型),并对其EVF发生率、基线特征及临床预后进行比较。应用多变量logistic回归分析HT和临床预后的独立危险因素。采用受试者操作特征曲线(ROC)分析EVF预测HT-Ⅱ型的效能。结果98例接受机械取栓患者纳入分析,其中HT阴性48例(49.0%,48/98)、HT-Ⅰ型40例(40.8%,40/98)、HT-Ⅱ型10例(10.2%,10/98)。3组患者的年龄及心房颤动、EVF、预后不良发生率的差异具有统计学意义(P<0.05)。多变量logistic回归分析显示EVF[优势比(OR)5.962,95%CI 1.750~8.964,P=0.001]和心房颤动(OR 3.485,95%CI 1.962~18.986,P=0.028)是发生HT-Ⅱ的独立危险因素;未发现HT-Ⅰ的独立危险因素;基线美国国立卫生研究院卒中量表(NIHSS)评分(OR 1.162,95%CI 1.021~1.345,P=0.038)、EVF(OR 5.358,95%CI 1.665~13.653,P=0.006)和HT-Ⅱ(OR 1.326,95%CI 1.226~2.038,P=0.032)是预后不良的独立危险因素。EVF预测HT-Ⅱ的灵敏度、特异度分别为80.0%、86.4%,ROC曲线下面积为0.832。结论急性脑梗死机械取栓后血管造影出现EVF预示再通后HT-Ⅱ型出血转化风险增加及预后不良。     

The benefit of intravenous thrombolysis prior to mechanical thrombectomy within the therapeutic window for acute ischemic stroke

The increase in risk for acute ischemic stroke (AIS) with age is well established. If not treated properly and promptly, AIS can result in permanent neurological damage and even death. This literature review assesses the clinical outcomes of AIS patients treated with both intravenous thrombolysis (IVT) prior to mechanical thrombectomy (MT) compared to those treated solely with mechanical thrombectomy. Randomized controlled trials (RCTs) and meta-analyses published from 2015 to 2020 and available on PubMed were selected for review, and their quantitative and qualitative findings were extrapolated and summarized. Post-hoc analyses from ASTER and ETIS trials were reviewed as well as the impact of combined therapy and monotherapy on large vessel occlusions (LVO). Clinical outcomes in all examined trials demonstrated significant successful reperfusion as well as a higher rate of functional independence at 90 days for IVT prior to MT. Concerns of thrombus fragility, safety and cost effectiveness of dual therapy are also addressed. Based on these findings, we recommend the use of IVT as a pretreatment procedure to MT for AIS when eligible for IVT. Recent articles further strengthen this recommendation and provide new insights that IVT prior to MT is especially beneficial for patients presenting with multiple LVOs localized to the anterior intracranial circulation. Additional multi-center RCTs are necessary for further analysis of statistical outcomes demonstrating mixed effects.     

机械取栓治疗院内外急性缺血性脑卒中疗效的倾向性匹配研究

本文回顾性分析2015年1月至2018年12月于南京医科大学第一附属医院接受机械取栓治疗的6 h时间窗内的急性前循环大血管闭塞的26例院内和167例院外患者临床资料,探讨机械取栓治疗院内、外急性缺血性脑卒中患者的临床疗效。根据发病时间、美国国立卫生研究院卒中量表(NIHSS)评分、年龄、性别,院内卒中与院外卒中按1:2进行倾向性配对后,采用独立样本t检验或χ2检验比较两组患者的基线资料及手术情况、术后90 d预后的差异。匹配后,26例院内卒中和52例院外卒中患者纳入本研究。院内卒中患者接受静脉溶栓比例低于院外患者(11.54%和46.15%;χ2=9.176,P=0.002)。院内卒中患者更常见合并心功能不全(19.23%和3.85%;χ2=5.022,P=0.038)。院内卒中和院外卒中患者机械取栓后成功再灌注比例分别为84.62% (22/26)和75.00%(39/52),差异无统计学意义(χ2=0.458,P= 0.312)。院内外卒中患者90 d预后良好率分别为30.77%(8/26)和46.15%(24/52),差异无统计学意义(χ2=2.676 ,P=0.145 )。院内外卒中患者症状性颅内出血发生率分别为15.38%(4/26)和17.31%(9/52),90 d死亡率分别为23.08% (6/26)和19.23%(10/52),差异均无统计学意义(χ2=0,P>0.999;χ2=0.157,P= 0.692)。本研究结果表明,在卒中后6 h时间窗内,院内、外卒中患者接受机械取栓治疗同样安全有效。     

Mechanical thrombectomy with snare in patients with acute ischemic stroke

Introduction We evaluated the efficacy and safety of thrombus extraction using a microsnare in patients with acute ischemic stroke (AIS). Methods This was a prospective, observational, cohort study in which consecutive patients with AIS (<6 hours of ischemia for anterior circulation and <24 hours for posterior circulation) who had been previously excluded from intravenous tissue plasminogen activator (tPA) thrombolysis were included and followed-up for 3 months. Mechanical embolectomy with a microsnare of 2–4 mm was undertaken as the first treatment. Low-dose intraarterial thrombolysis or angioplasty was used if needed. TIMI grade and modified Rankin stroke scale (mRSS) score were used to evaluate vessel recanalization and clinical efficacy, respectively. Results Nine patients (mean age 55 years, range 17–69 years) were included. Their basal mean NIHSS score was 16 (range 12–24). In seven out of the nine patients (77.8%) the clot was removed, giving a TIMI grade of 3 in four patients and TIMI grade 2 in three patients. Occlusion sites were: middle cerebral artery (four), basilar artery (two) and anterior cerebral artery plus middle cerebral artery (one). The mean time for recanalization from the start of the procedure was 50 min (range 50–75 min). At 3 months, the mRSS score was 0 in two patients and 3–4 in three patients (two patients died). Conclusion According to our results, the microsnare is a safe procedure for mechanical thrombectomy with a good recanalization rate. Further studies are required to determine the role of the microsnare in the treatment of AIS.     

后循环急性缺血性脑卒中患者经机械取栓完全复流后不良预后的影响因素分析

目的探索后循环急性缺血性脑卒中（PCS）患者经机械取栓并完全恢复前向血流后部分患者临床预后仍然不佳的影响因素。 方法连续纳入2017年1月至2020年9月于我院接受机械取栓治疗的PCS患者并进行回顾性分析。闭塞血管完全恢复前向血流定义为改良脑梗死溶栓血流分级（mTICI）达3级。90 d改良Rankin评分（mRS）> 2分则被定义为预后不良。将患者基线资料、治疗相关指标纳入多因素分析,并采用受试者工作特征曲线（ROC）来确定最佳界值。 结果共纳入39例经机械取栓治疗后完全恢复前向血流（mTICI 3级）的PCS患者。其中,预后不良患者共20例（51.3%）。采用逐步Logistic回归分析显示,入院时美国国立卫生研究院卒中量表（NIHSS）评分较高（OR = 1.21,95%CI = 1.037~1.414,P = 0.016）、后交通动脉（PcomA）未开放（OR = 0.052,95%CI = 0.005~0.557,P = 0.014）为90 d不良预后的独立预测因素。基于ROC曲线分析显示,入院时NIHSS评分曲线下面积为0.762,截断值为20分,敏感度为70.0%,特异度为84.2%。 结论入院时NIHSS评分高、后交通动脉未开放,是后循环急性缺血性脑卒中患者接受机械取栓治疗并完全恢复前向血流后临床预后仍不佳的相关因素。     

基于CiteSpace的近10年急性缺血性卒中机械取栓领域献计量可视化分析

【摘要】 目的 对Web of Science中近10年国内外急性缺血性卒中机械取栓领域的文献进行计量和可视化分析,探讨该领域研究现状和发展趋势。方法 运用文献计量学CiteSpace 5.8.R3软件,以Web of Science核心合集数据库为检索源,对2012～2021年急性缺血性卒中机械取栓领域的相关文献,进行共现/共被引网络分析及图形可视化。结果 经筛选本研究共纳入4 946篇文献,近10年全球发文量呈上升趋势,中国发文量位居第3,美国处于核心领先地位,被引频次排名前10位文献的作者和发表论文数量前10位的作者均为国外研究人员;发文量前10位的机构中首都医科大学是唯一上榜的中国机构,位列第7;近10年研究热点聚焦于急性缺血性卒中的治疗方式和取栓器材上;发展趋势与前沿将继续集中在急性缺血性卒中治疗的临床研究。结论 近年来全球急性缺血性卒中机械取栓研究领域发展迅猛,中国和西方发达国家之间差距明显,未来的研究趋势可能仍为取栓装置的探索创新和疾病治疗的临床研究。     

Mechanical thrombectomy for acute stroke

BACKGROUND AND PURPOSE: We evaluated a mechanical thrombectomy protocol to treat acute stroke and report the angiographic results and clinical outcomes. METHODS: Patients with anterior circulation strokes <8 hours and posterior circulation strokes <12 hours were treated at a single center over 10 months. Patients were excluded if they were candidates for intravenous tissue plasminogen activator (tPA). Treatment involved one of two mechanical thrombectomy devices. Retrieval was augmented by low-dose intra-arterial tPA if needed. Outcome was measured by using the Modified Rankin score. RESULTS: Ten patients were treated: five with anterior circulation strokes, four with posterior circulation strokes, and one with embolic strokes involving both circulations. Mean National Institutes of Health Stroke Scale score at presentation was 24.6 +/- 10.9. In eight patients (80%), revascularization was successful (Thrombolysis in Acute Myocardial Infarction score, 3). Mean time from symptom onset to initiation of the procedure was 6 hours (5.3 hours for anterior circulation and 7.0 hours for posterior circulation). Mean time for recanalization from the start of the procedure was 1.17 +/- 0.58 hours for the six anterior circulation strokes and 2.75 +/- 1.34 hours in the two posterior circulation strokes. Five patients died within 48 hours; all had posterior circulation strokes. Mean Modified Rankin score at 90 days was 1.4. CONCLUSION: In this small series, mechanical thrombectomy of acute stroke appeared to improve recanalization rates compared with intra-arterial thrombolysis. No hemorrhagic complications occurred. Further study is required to determine the role of these techniques.     

机械取栓在急性血栓性脑卒中中的应用

急性血栓性脑卒中是严重威胁人类健康的常见病,其治疗方法主要有静脉溶栓、动脉溶栓和机械取栓.近年来,对于不适合静脉溶栓或静脉溶栓失败的患者,机械取栓由于其所取得的较好的效果受到越来越多的关注,现就其有关方面予以综述.     

Predictive factors of outcome and hemorrhage after acute ischemic stroke treated by mechanical thrombectomy with a stent-retriever

Introduction

The study attempts to identify notable factors predicting poor outcome, death, and intracranial hemorrhage in patients with acute ischemic stroke undergoing mechanical thrombectomy with stent retriever. These data could be useful to improve the selection of patients for thrombectomy.

Methods

Patients with acute ischemic stroke treated with the Solitaire FR device were retrospectively analyzed from a prospectively collected database. We assessed the effect of selected demographic characteristics, clinical and imaging factors on poor outcome at 3 months (modified Rankin score 3–6), mortality at 3 months, and hemorrhage at day 1 (symptomatic and asymptomatic).

Results

From May 2010 to April 2012, 59 consecutive patients with an acute ischemic stroke underwent mechanical thrombectomy. At 3 months, 57.6 % of the patients were functionally independent (modified Rankin Scale 0–2) and mortality was 20.4 %. Multivariate analyses revealed that a thrombus length?>?14 mm (p?=?0.02; OR 7.55; 95 % CI 1.35–42.31) and longer endovascular procedure duration (p?=?0.01; OR 1.04; 95 % CI 1.01–1.07) were independently associated with poor outcome. A higher baseline Alberta Stroke Program Early CT (ASPECT) score (p?=?0.04; OR 0.79 per point; 95 % CI 0.63–0.99) and successful recanalization (p?=?0.02; OR 0.07; 95 % CI 0.01–0.72) were independent predictors of good functional outcome. Baseline ASPECT score (p?<?0.01; OR 0.65; 95 % CI 0.54–0.78) independently predicted symptomatic intracranial hemorrhage at day 1.

Conclusion

Absolute baseline ASPECT score reflects early symptomatic hemorrhage risk and functional outcome at 3 months. Thrombus length measured on MRI play an important role on functional outcome at 3 months after thrombectomy. Further analyses are needed to determine its importance in the selection of patients for mechanical thrombectomy.     

急性缺血性脑卒中介入取栓治疗的预后及其影响因素

 目的 探讨急性缺血性脑卒中(acute ischemic stroke,AIS)介入取栓治疗的预后及其影响因素。方法 选取2017-01至2019-07在医院神经内科接受介入取栓治疗的106例AIS患者,根据术后3个月患者改良Rankin评分评估预后水平,分为预后良好组和预后不良组,对两组患者各项临床资料进行分析,对比预后的相关因素及危险因素,并对认知功能和预后血清神经相关因子表达水平进行对比。结果 患者年龄大、合并冠心病、术前血清CRP及Hcy高、阻塞血管再通时间较长、术后36 h存在部分再通均为AIS介入治疗预后不良的危险因素(OR>1,P<0.05);预后良好组的认知功能、运动功能、语言功能均优于预后不良组,差异有统计学意义(P<0.05);两组患者吞咽功能差异无统计学意义。预后良好组血清神经相关因子表达水平均优于预后不良组,差异有统计学意义(P<0.05)。结论 预后良好AIS患者各项功能与血清神经相关因子表达水平状态均较好,对年龄较大、发病至就诊时间较长、合并冠心病,且术前血清CRP、Hcy、NIHSS评分偏高,阻塞血管再通时间较长及术后36 h内仅达到部分再通的患者应给予充分重视,对危险因素积极预防,提高预后水平。     

Multimodal CT assessment of acute ischemic stroke

Aim of the work

To evaluate the role of multimodal CT [non-enhanced CT (NECT), CT perfusion (CTP), and CT angiography (CTA)] in selection of acute ischemic stroke patients for reperfusion therapy.

Patients and methods

This prospective study included 35 patients with evidence of acute stroke in the middle cerebral artery territory of less than 12 h duration. Patients underwent multimodal CT including: (1) NECT (2) CTP (3) CTA. Qualitative and quantitative interpretation of the CTP was done to differentiate penumbra and infarction. CTA was evaluated for arterial occlusion or stenosis and the presence of collaterals.

Results

The areas of infarction showed a significant decrease in CBF (p = 0.03) and CBV values (p = 0.01) compared to the corresponding area in the contralateral normal hemisphere. The areas of penumbra showed a significant decrease in CBF (p = 0.04) and insignificant difference in CBV (p = 0.2) compared to the corresponding area in the contralateral normal hemisphere. Cutoff values of 2.0 for the CBV and MTT > 130% of the contralateral normal hemisphere allowed the best differentiation of infarction and penumbra.

Conclusion

Multimodal CT imaging fulfills all the requirements for selection of patients for reperfusion therapy and so helps in stroke treatment decisions.     

尘肺CT扫描方案的探讨

目的比较常规剂量CT、低剂量CT及高分辨率CT（HRCT）3种扫描方案对尘肺的诊断能力,以期确定最佳方案。方法 37例经专业机构确诊的尘肺患者均经常规剂量CT、低剂量CT及HRCT3种方案扫描。采用统计学方法分析与比较该3种方案对尘肺特征性表现,小阴影、大阴影及进行性团块状纤维化（PMF）及纤维化早期表现及合并症的检出率。结果 3种扫描方案对小阴影、大阴影及团块状纤维化（PMF）的检出例数相符,均为36例、20例及16例,而对于大、小阴影及PMF周围的瘢痕肺气肿、肺纹理扭曲等征象,以HRCT显示较清晰。HRCT对早期肺间质纤维化,诸如胸膜改变、小叶间隔增厚、小叶肺气肿及蜂窝状影的显示例数显著多于其他两组（P〈0.05）。除肺气肿外,3种方案对其他合并症肺结核、肺癌及呼吸系统感染等的检出率无明显差别。结论低剂量CT与常规剂量CT均可用于尘肺的普查与诊断,为减少受检者的辐射剂量,应尽可能采用低剂量CT扫描。而对于肺间质改变的观察,HRCT应作为首选方案。     

Factors predicting hemorrhagic complications after multimodal reperfusion therapy for acute ischemic stroke

BACKGROUND AND PURPOSE: We sought to find predictors for hemorrhagic complications in patients with acute ischemic stroke treated with multimodal endovascular therapy. MATERIALS AND METHODS: We retrospectively reviewed patients with acute ischemic stroke treated with multimodal endovascular therapy from May 1999 to March 2006. We reviewed clinical and angiographic data, admission CT Alberta Stroke Programme Early CT Score (ASPECTS), and the therapeutic endovascular interventions used. Posttreatment CT scans were reviewed for the presence of a parenchymal hematoma or hemorrhagic infarction based on defined criteria. Predictors for these types of hemorrhages were determined by logistic regression analysis. RESULTS: We identified 185 patients with a mean age of 65+/-13 years and mean National Institutes of Health Stroke Scale score of 17+/-4. Sixty-nine patients (37%) developed postprocedural hemorrhages: 24 (13%) parenchymal hematomas and 45 (24%) hemorrhagic infarctions. Patients with tandem occlusions (odds ratio [OR] 4.6 [1.4-6.5], P<.016), hyperglycemia (OR 2.8 [1.1-7.7], P<.043), or treated concomitantly with intravenous (IV) tissue plasminogen activator (tPA) and intra-arterial (IA) urokinase (OR 5.1 [1.1-25.0], P<.041) were at a significant risk for a parenchymal hematoma. Hemorrhagic infarction occurred significantly more in patients presenting with an ASPECTS相似文献   

“一站式”CT评价急性缺血性脑卒中缺血半暗带的研究进展

急性缺血性脑卒中（AIS）是最常见的致死性和致残性神经系统疾病。影像新技术可快速有效地协助确定诊断、分析病因、指导治疗和判断预后。综述由CT 平扫、CT 灌注成像及 CT 血管成像组成的“一站式”CT 在AIS诊断中的应用,明确CT灌注成像的临床价值及诊断方法。探讨缺血半暗带对于AIS再灌注治疗的指导意义,使病人获得最佳的风险收益比。     

支架机械再通术治疗急性期缺血性脑卒中

目的 初步评价支架机械再通术治疗急性期缺血性脑卒中的疗效及安全性.方法 回顾性分析支架机械再通术治疗的12例急性期缺血性脑卒中患者的临床资料,其中前循环病变10例,后循环病变2例.结果 11例患者支架成功释放(成功率92%),支架置入术后闭塞血管均得到不同程度再通,完全再通(TIMI 3级)率为58.3%(7/12),...     

基于多模态CT评估缺血性脑卒中侧支循环的研究进展

脑卒中具有发病率高、致残率高、死亡率高和复发率高的特点,在脑卒中患者中,缺血性脑卒中所占比例较大.当缺血性脑卒中患者缺血部位神经发生不可逆性损伤时,致残或致死率将大大增加.尽早恢复患者血供至关重要,而侧支循环的状态决定了梗死区域血供的代偿情况,因此,准确快速地评估缺血性脑卒中患者的侧支循环状态极其重要.目前,评估侧支循...     

Differentiating intraparenchymal hemorrhage from contrast extravasation on post-procedural noncontrast CT scan in acute ischemic stroke patients undergoing endovascular treatment

Introduction

This study aimed to identify the imaging characteristics that can help differentiate intraparenchymal hemorrhage from benign contrast extravasation on post-procedural noncontrast CT scan in acute ischemic stroke patients after endovascular treatment.

Methods

We reviewed the clinical and imaging records of all acute ischemic stroke patients who underwent endovascular treatment in two hospitals over a 3.5-year period. The immediate post-procedural CT scan was evaluated for the presence of hyperdense lesion(s). The average attenuation of the lesion(s) was measured. Intraparenchymal hemorrhage was defined as a persistent hyperdensity visualized on follow-up CT scan, 24 h or greater after the procedure.

Results

Of the 135 patients studied, 74 (55 %) patients had hyperdense lesion(s) on immediate post-procedural CT scan. Follow-up scans confirmed the diagnosis of intraparenchymal hemorrhage in 20 of these 74 patients. A receiver operating characteristic analysis showed that the average attenuation of the most hyperdense lesion can differentiate intraparenchymal hemorrhage from contrast extravasation with an area under the curve of 0.78 (p?=?0.001). An average attenuation of <50 Hounsfield units (HU) in the most visually hyperattenuating hyperdense lesion had 100 % specificity and 56 % sensitivity for identification of contrast extravasations. Petechial hyperdensity was seen in 46/54 (85 %) patients with contrast extravasation versus 9/20 (45 %) patients with intraparenchymal hemorrhage on the immediate post-procedural CT scan (p?Conclusion An average attenuation <50 HU of the most hyperattenuating hyperdense parenchymal lesion on immediate post-procedural CT scan was very specific for differentiating contrast extravasation from intraparenchymal hemorrhage in acute ischemic stroke patients after endovascular treatment.