Complication rates using balloon-expandable and self-expanding stents for the treatment of intracranial atherosclerotic stenoses

Introduction

Using balloon-expandable stents (BES) for treatment of intracranial stenoses, high inflation pressures and rigidity of the device are regarded as major drawbacks limiting feasibility and safety of the procedure. Self-expanding stents (SES) were developed to facilitate lesion access and to allow for less aggressive dilatation. We analyzed data of the INTRASTENT multicentric registry to assess whether self-expanding stents significantly reduced peri-interventional complication rates.

Methods

Records of intracranial stent procedures were entered consecutively into the registry. Datasets were divided into two groups according to the type of stent used. For outcome measurement, we chose three categories: TIA/minor stroke [modified Rankin score (mRS) <2], disabling stroke, and patient death. Clinical outcome was compared between BES and SES. We analyzed types of adverse events occurring in each group in addition.

Results

Of 409 atherosclerotic lesions, 254 were treated with BES and 155 with SES. Technical success rates were 97.6% and 98.7%, respectively. Adverse event rates were 4.9%, 3.7%, and 0.8% for TIA/nondisabling stroke, disabling stroke, and death in the BES group compared with 5.3%, 6.0%, and 4.0% in the SES group. The differences were not statistically significant. We observed more perforator strokes after use of BES, but thromboembolic events occurred more often in the SES treatment group.

Conclusion

Data of the INTRASTENT registry do not support the hypothesis that introduction of SES lowered the overall complication rate of intracranial stent procedures. There might be an advantage using self-expanding stents in vessel segments with important perforating arteries.     

Utilization of self-expanding stents in the treatment of intracranial atherosclerotic disease in the distal small cerebral vessels

Introduction Previously, endovascular treatment of stenosis related to intracranial atherosclerosis (ICAD) involving arteries measuring less than 2 mm in diameter was limited. To our knowledge, there are no reports in the literature addressing stent placement for treatment of stenosis in arteries of this size. Methods Four patients aged 33 to 80 years (mean 57.5 years) with medically refractory ICAD underwent angioplasty and stenting of small (<2 mm) distal intracerebral arteries. Vessel location and length of follow-up were anterior cerebral artery (ACA) A1 segment (5 months), ACA A2 segment (18 months), middle cerebral artery M1 segment (18 months), and posterior cerebral artery P1 segment (8 months) with vessel calibers ranging from 1.2 to 1.8 mm. Clinical and imaging follow-up ranged from 5 to 18 months. Results All procedures were successfully performed without complications. Follow-up out to 18 months demonstrated one vessel that went on to occlusion while the other stented vessel segments remained patent. One patient died 8 months after stenting, but the death was not related to neurological disease. The remaining patients experienced resolution of the presenting symptomatology and remained asymptomatic throughout follow-up. Conclusion In this small series, stenoses of distal (<2 mm) cerebral arteries were amenable to treatment using new self-expanding stents. We safely and successfully treated four arteries smaller than 2 mm in diameter with newer self-expanding stents. All patients remained clinically asymptomatic. One stent occluded at 5 months and the others remained patent during follow-up. Longer term clinical follow-up is required to determine the durability and viability of this therapy.     

Use of self-expanding stents in distal small cerebral vessels

BACKGROUND: Previously, endovascular treatment of wide-necked aneurysms and stenosis involving small vessels measuring <2 mm in diameter was limited. There are no reports in the literature addressing stent placement in small distal cerebral vessels. Recent experience with the Neuroform stent has shown that this device can be safely and effectively used to treat aneurysms in vessels of this caliber. MATERIALS AND METHODS: We report 8 cases of Neuroform stent placement into cerebral vessels measuring <2 mm in diameter (range, 1.1-1.8 mm). All stents were placed for aneurysm treatment in conjunction with coiling. Lesion locations and number were as follows: anterior communicating artery region (n = 5), pericallosal artery A2-A3 (n = 1), middle cerebral artery (MCA) M1-M2 (n = 1), and MCA M3-M4 (n = 1). Clinical follow-up ranged from 4.5 to 18 months. Imaging follow-up was performed with MR imaging/MR angiography. RESULTS: All procedures were successfully performed without immediate or delayed device-related complications. Intraprocedural thrombus developed within the stent in 2 patients and immediately resolved with 10 mg of intra-arterial abciximab. Follow-up at 18 months demonstrated durable results. There were no clinical neurologic symptoms related to the treated vessel territory at follow-up. CONCLUSION: Development of newer low-profile endovascular devices allows access and ability to treat lesions farther out in the smaller cerebral vessels. We have safely and successfully treated 8 vessels smaller than 2 mm in diameter with newer self-expanding stents with good short- and intermediate-term results. Further follow-up and more experience are necessary to determine long-term results.     

Initial experience with a self-expanding retrievable stent for recanalization of large vessel occlusions in acute ischemic stroke

Introduction  

Quicker recanalization results in better clinical outcomes in patients with acute ischemic strokes. We describe our experience with the use of a self-expanding, fully retrievable stent in acute intracranial occlusions.     

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),...     

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.     

Endovascular treatment of acute ischemic stroke: current indications

Endovascular stroke therapy is an effective means of achieving reperfusion in stroke patients with proximal cerebral artery occlusions. However, current guideline recommendations express uncertainty regarding the clinical efficacy of catheter-based treatments, given the lack of supportive trial data. A critical problem is that it remains unclear which patients will benefit from endovascular therapy. As such, patient selection is likely highly variable in clinical practice. This article will review the existing data to discuss the clinical and imaging factors that are relevant to patient outcomes, and which may be used to guide endovascular treatment decisions. Anterior circulation strokes represent the primary focus of this review.     

Venous stenoses in dialysis shunts: treatment with self-expanding metallic stents

A flexible, self-expanding metallic endoprosthesis was employed for the treatment of venous outflow stenoses in four patients with a polytetrafluoroethylene shunt and two patients with a Brescia-Cimino shunt. The stenoses had led to shunt occlusion in five patients and to flow impairment in one. In the occluded shunts, thrombectomy and subsequent balloon angioplasty were performed in four patients, and percutaneous recanalization with angioplasty was performed in one. One shunt with decreasing flow was percutaneously dilated. Since the underlying stenoses recurred in four patients after 24 hours and did not respond sufficiently to angioplasty in two patients, up to four stents were placed in the venous segments. Thrombosis of the stents occurred in two patients after 24 hours and in one after 6 weeks and was successfully recanalized with thrombectomy in two. At 2-6 months follow-up, the stents and the shunts were patent in five patients. In three of these patients, intima hyperplasia, associated with narrowing of the stent lumen in two, was noted within 4 months after stent placement.     

Elastic characteristics of the self-expanding metallic stents

We measured elastic properties of the self-expanding metallic (Gianturco) stent using Hooke's law to characterize the stent with respect to its caliber, length, and radius by a coefficient of stiffness. Although this coefficient was independent of the radius of the stent, we found that it was directly dependent on caliber. For a stent of a particular caliber and length, the fractional change in radius determined the force exerted by the stent. For small radial displacements of the stent, the force required to compress it was directly proportional to the radial displacements; for large displacements, the force depended on a power series of the fractional radial displacement. A hyperbolic function was empirically introduced to approximate this type of relationship between force and radial displacement. We calculated tension and pressure exerted by the stent and suggest the use of our findings with normal vessels.     

血浆D-二聚体水平对急性缺血性脑卒中颅内动脉粥样硬化性大血管闭塞的预测价值北大核心CSCD

目的评价血浆D-二聚体水平对接受脑动脉再通治疗的急性缺血性脑卒中(AIS)患者血管闭塞类型的预测价值。方法回顾性分析2019年1月至2020年8月于南京医科大学第一附属医院接受脑动脉再通治疗的AIS患者临床资料。根据术中血管造影结果,将患者分为急性颅内动脉粥样硬化性狭窄(ICAS)所致大血管闭塞(LVO)(ICAS-LVO组)和非ICAS所致LVO(非ICAS-LVO组)。所有患者均在到达急诊时接受血样采集,检测D-二聚体(D-D)水平。采用单因素和多因素logistic回归分析确定ICAS-LVO相关预测因子,与D-D相关性;受试者工作特征曲线(ROC)评价D-D水平预测ICAS-LVO的价值。结果共纳入273例患者。其中79例(28.9%)患者诊断为ICAS-LVO。与非ICAS-LVO组患者相比,ICAS-LVO组患者更年轻,男性比例更高,有吸烟史者更多,伴心房颤动更少,美国国立卫生研究院卒中量表(NIHSS)评分基线值更低(均P<0.05)。ICAS-LVO组患者血浆D-D水平显著低于非ICAS-LVO组患者(0.39 mg/L比1.20 mg/L,P<0.01)。多因素logistic回归分析显示,较低D-D与ICAS-LVO呈显著正相关(OR=0.30,95%CI=0.18~0.47,P<0.01)。基于ROC,血浆D-D预测ICAS-LVO的最佳临界值为0.84 mg/L,灵敏度为84.8%,特异度为67.5%,阴性预测值为91.6%,曲线下面积(AUC)为0.830。结论基线低D-D水平是ICAS-LVO的独立预测因子,有助于神经介入医师预先制定血管再通治疗策略。     

Imaging of acute ischemic stroke

For decades, imaging has been a critical component of the diagnostic evaluation and management of patients suspected of acute ischemic stroke (AIS). With each new advance in the treatment of AIS, the role of imaging has expanded in scope, sophistication, and importance in selecting patients who stand to benefit from potential therapies. Although the field of stroke imaging has been evolving for many years, there have been several major recent changes. Most notably, in late 2017, the window for treatment expanded to 24 h from onset of stroke symptoms in selected patients. Furthermore, for those patients in expanded time windows, guidelines issued in early 2018 now recommend the use of “advanced” imaging techniques in the acute setting, including CT perfusion and MRI, to guide therapeutic decision-making. With these and other changes, the emergency radiologist must be prepared to handle a growing volume and complexity of AIS imaging. This article reviews the various imaging modalities and techniques employed in the imaging of AIS patients, with an emphasis on recommendations from recent randomized controlled trials and national consensus guidelines.     

Treatment of acute ischemic stroke

Ischemic stroke is a medical emergency requiring fast and effective collaboration of neurologists and radiologists. Currently there are promising new developments in the treatment of acute ischemic stroke with efforts being made to reduce the door-to-needle time and to improve recanalization of occluded vessels by new endovascular techniques. Clinical trials have also demonstrated the efficacy of thrombolysis up to 4.5?h and confirmed the importance of the time to treatment for positive outcome.     

非小卒中患者急性期强化他汀治疗的疗效及安全性

 目的 观察非小卒中患者急性期强化他汀治疗的疗效及安全性。方法 选取发病24 h内非小卒中患者125例,按随机数字表法分为阿托伐他汀强化组(62例)和常规组(63例)。强化组及常规组从入院起分别予阿托伐他汀40 mg、20 mg,每晚一次口服,监测治疗前、发病2周总胆固醇(Tch)、三酰甘油(TG)、高密度脂蛋白(HDL-C)、低密度脂蛋白(LDL-C)、肝功能、肌酸激酶,并记录治疗前后美国国立卫生院卒中量表(NIHSS评分)、治疗后改良Rankin量表(mRS)、治疗后症状性脑梗死后出血转化事件,以及发病3个月脑梗死复发情况。结果 经治疗两组患者NIHSS评分较治疗前下降,强化组患者NIHSS评分下降更为明显(P<0.05)。强化组患者发病2周时mRS评分低于常规组(P<0.05)。发病3个月后两组均有脑梗死复发患者,两组间差异无统计学意义。2周后复测血脂,经治疗两组患者Tch、TG、LDL-C均较治疗前下降,且强化组的Tch、TG、LDL-C水平均低于常规组(P<0.05)。治疗后两组均有肝功异常、CK异常及症状性出血转化的病例,其发生率两组间差异无统计学意义。结论 非小卒中患者急性期强化他汀治疗可改善血脂水平、促进神经功能恢复,且无明显不良反应发生。     

新型可回撤自膨胀支架在颅内动脉瘤治疗中的应用

目的评价新型可回撤自膨胀支架(LEO)在颅内动脉瘤治疗中的应用价值。方法回顾分析应用LEO支架治疗的43例患者44枚颅内动脉瘤,其中单纯支架治疗16例,支架结合弹簧圈治疗25例,双支架治疗2例,双支架结合弹簧圈治疗1例。并对其进行影像学及临床随访。结果治疗中支架位置调整方便,所有病例支架均成功释放,1例位置欠理想,1例发生急性支架内血栓,随访中1例发生晚期支架内血栓,1例发生内膜过度增生,22枚(50.0%)动脉瘤达即刻致密栓塞,29例获得影像随访的患者中72.4%动脉瘤治愈或较前好转,13.8%动脉瘤稳定,3例夹层动脉瘤发生瘤体短期内增大,2例患者死亡。结论LEO系统具有释放可控性强、简捷安全、可选择型号广泛等优点,在颅内动脉瘤栓塞和管壁重建中有一定优势。     

Computed tomography in acute ischemic stroke

Stroke remains the third most important cause of mortality in industrialized countries; this has prompted research for improvements in both diagnostic and therapeutic strategies for patients with signs of acute cerebral ischemia. Over the last decade, there has been a parallel in progress in techniques in both diagnostic and therapeutic options. While previously only used for excluding hemorrhage, imaging now has the possibility to detect ischemia, vascular occlusion, as well as detect tissue at risk in one setting. It should also allow to monitor treatment and predict/exclude therapeutic complications. Parallel to advances in magnetic resonance imaging of stroke, computed tomography has improved immensely over the last decade due to the development of CT scanners that are faster and that allow to acquire studies such as CT perfusion or CT angiography in a reliable way. CT can detect many signs that might help us detect impending signs of massive infarction, but we still lack the experience to use these alone to prevent a patient from benefitting from possible therapy.     

机械辅助动脉内溶栓治疗急性缺血性脑卒中

目的评估机械辅助动脉内尿激酶溶栓治疗缺血性脑卒中的临床疗效及安全性。方法 2007年1月至2010年10月对28例急性缺血性脑卒中患者,于发病时间在90～450 min行机械辅助动脉内尿激酶溶栓治疗。采用的机械辅助方法有导丝碎栓、导管抽吸取栓及支架应用等,术后统计血管再通率、出血并发症及3个月后改良Rankin量表(mRS)评分。结果 28例患者应用机械辅助溶栓成功再通血管23例,血管再通率为82.1%,平均血管再通时间为65.22 min,3个月后mRS评分均≤3分;5例血管再通无效者中2例死亡,1例mRS评分4分,2例mRS评分≤3分。血管再通组中,机械辅助溶栓并未增加出血并发症率。结论机械辅助溶栓治疗急性缺血性脑卒中安全有效,能减少尿激酶用量及血管再通时间,提高再通率。     

尿激酶动脉内溶栓治疗急性脑梗死致症状性脑出血多因素分析

目的 探讨尿激酶局部动脉内溶栓治疗急性缺血性脑梗死并发症状性脑出血的原因及防治措施.方法 我院从1999年2月至2004年6月共有217例急性缺血性脑梗死进行尿激酶局部动脉内溶栓治疗,我们对并发症状性脑出血的密切相关因素利用SPSS11.5软件进行多因素逻辑回归分析,评价这些因素的风险.结果 症状性颅内出血共有8例（3.7%）,溶栓前高水平的收缩压[比数比（OR）,1.096;比数比的95%可信区间（CI）,1.006～1.194]和尿激酶治疗（OR, 1.068;95%CI,1.053～1.247）是预测症状性脑出血的因素.在溶栓患者,随收缩压升高,症状性脑出血的风险随之增高,其他年龄、溶栓开始时间、溶栓时脑卒中评分（NIHSS）、糖尿病、侧支循环因素均不能预测症状性脑出血发生与否.结论 尿激酶局部动脉内溶栓治疗急性缺血性脑梗死并发症状性脑出血,与溶栓前高水平的收缩压和尿激酶治疗有关.     

Preliminary experience with Leo self-expanding stent for the treatment of intracranial aneurysms

We report initial experience with the use of a new intracranial stent, the Leo microstent in combination with detachable coils in treatment of patients with wide-necked cerebral aneurysms. The Leo stent represents a significant advance in the vascular treatment of intracranial aneurysm with high radial force and an easy delivery system. It is a feasible, secure, and effective system.