Acute Stroke: Present and Future of Catheter-Based Interventions

Abstract : Acute ischemic stroke is a major cause of morbidity and mortality in industrialized nations. The sequel of stroke ranges from mild to severe disability and even death. Since the impairment may be permanent, the costs to society from work incapacity and the need for long-term care can be high. Additionally, the burden of suffering associated with the disease may have devastating effects on individuals and families. Following the occlusion of a cerebral vessel, the full extent of the infarction may not become clinically and radiologically apparent until days after. By then, the surrounding watershed zone, or penumbra, either survives or succumbs to necrosis over time. The natural history of this "tissue at risk” is determined by two factors: the collateralization from other vascular territories and the possible occurrence of spontaneous recanalization of the occluded vessel. The current treatment options for acute ischemic stroke are aiming at an early and sustained restoration of flow to the penumbra. The effect of the treatment is therefore time-dependent and the neurologic outcome is a function of the time span between onset of symptoms and recanalization therapy as well as of the recanalization rate associated with a specific treatment. This report summarizes the results of the major trials on catheter-based interventions, either using thrombolytic drugs or novel mechanical approaches being developed to treat patients with acute ischemic strok

The use of flat panel angioCT (DynaCT) for navigation through a deformed and fractured carotid stent

Navigation through a previously deployed and deformed stent is a difficult interventional task. Inadvertent navigation through the struts of a stent can potentially lead to incomplete secondary stent extension and vessel occlusion. Better visualisation of the pathway through the stent can reduce the risks of the procedural complications and reduce the reluctance of the interventionalist to navigate through a previously deployed stent. We describe a technique of visualisation of the pathway navigated by a guidewire through a previously deployed deformed and fractured carotid stent by the use of DynaCT. Three-dimensional reconstruction of the stent/microwire allows excellent visualisation of the correct pathway of the microwire within the sten

Closing the gap between coil and balloon in the neurointerventional armamentarium? Initial clinical experience with a nitinol vascular occlusion plug

Introduction: The use of vascular plug devices for the occlusion of high-flow lesions is a relatively new and successful procedure in peripheral and cardiopulmonary interventions. We report on the use and efficiency of the Amplatzer vascular plug in a small clinical series and discuss its potential for occlusion of large vessels and high-flow lesions in neurointerventions. Methods: Between 2005 and 2007 four patients (mean age 38.5years, range 16-62years) were treated with the device, in three patients to achieve parent artery occlusion of the internal carotid artery, in one patient to occlude a high-flow arteriovenous fistula of the neck. The application, time to occlusion, and angiographic and clinical results and the follow-up were evaluated. Results: Navigation, positioning and detachment of the device were satisfactory in all cases. No flow-related migration of the plug was seen. The cessation of flow was delayed by a mean of 10.5min after deployment of the first device. In the procedures involving vessel sacrifice, two devices had to be deployed to achieve total occlusion. No patient experienced new neurological deficits; the 3-month follow-up revealed stable results. Conclusion: The Amplatzer vascular plug can be adapted for the treatment of high-flow lesions and parent artery occlusions in the head and neck. In this small series the use of the devices was uncomplicated and safe. The rigid and large delivery device and the delayed cessation of flow currently limit the device's use in neurointervention

Long-term outcome of symptomatic severe ostial vertebral artery stenosis (OVAS)

Introduction: The optimal management of patients with symptomatic severe ostial vertebral artery stenosis (OVAS) is currently unclear. We analyzed the long-term outcome of consecutive patients with OVAS who received either medical treatment (MT) or vertebral artery stenting (VAS). Methods: Thirty-nine (>70%) patients with severe OVAS were followed for a mean period of 2.8years. The decision for VAS (n = 10) or MT (n = 29) was left to the clinician. The Kaplan-Meier method was used to assess the risk of recurrent stroke, transient ischemic attack (TIA), or death over the study period. Results: Patients in the VAS group were significantly younger and more likely to have bilateral VA disease (P = 0.04 and P = 0.02). VAS was successfully performed in all ten patients. The periprocedural risk within 30days was 10% (one TIA). The overall restenosis rate was 10%. One restenosis occurred after 9months in a patient treated with bare-metal stent. At 4years of follow-up, VAS showed a nonsignificant trend toward a lower risk for the combined endpoint of TIA and stroke in posterior circulation compared to medical treatment (10% vs. 45%, P = 0.095; relative risk (RR) = 0.24, 95% confidence interval (CI) 0.031-1.85). Patients with bilateral VA disease had a significantly lower recurrence risk after VAS compared with medical treatment (0% vs. 91% at 4years, P = 0.004; RR 0.10, 95% CI 0.022-0.49) Conclusion: VAS was performed without permanent complications in this small series of patients with symptomatic severe OVAS. The long-term benefit seems to be confined to patients with bilateral but not to those with unilateral VA diseas

Closing the gap between coil and balloon in the neurointerventional armamentarium? Initial clinical experience with a nitinol vascular occlusion plug

INTRODUCTION: The use of vascular plug devices for the occlusion of high-flow lesions is a relatively new and successful procedure in peripheral and cardiopulmonary interventions. We report on the use and efficiency of the Amplatzer vascular plug in a small clinical series and discuss its potential for occlusion of large vessels and high-flow lesions in neurointerventions. METHODS: Between 2005 and 2007 four patients (mean age 38.5 years, range 16-62 years) were treated with the device, in three patients to achieve parent artery occlusion of the internal carotid artery, in one patient to occlude a high-flow arteriovenous fistula of the neck. The application, time to occlusion, and angiographic and clinical results and the follow-up were evaluated. RESULTS: Navigation, positioning and detachment of the device were satisfactory in all cases. No flow-related migration of the plug was seen. The cessation of flow was delayed by a mean of 10.5 min after deployment of the first device. In the procedures involving vessel sacrifice, two devices had to be deployed to achieve total occlusion. No patient experienced new neurological deficits; the 3-month follow-up revealed stable results. CONCLUSION: The Amplatzer vascular plug can be adapted for the treatment of high-flow lesions and parent artery occlusions in the head and neck. In this small series the use of the devices was uncomplicated and safe. The rigid and large delivery device and the delayed cessation of flow currently limit the device's use in neurointerventions

White matter lesions and intra-arterial thrombolysis

The aim of the study was to assess the influence of white matter lesions in patients with acute ischemic stroke treated with intra-arterial thrombolysis (IAT). From September 2003 to January 2010, we treated 400 patients with IAT at our institution. Of these patients, 292 were evaluated with MRI scans and included in this observational study. Clinical data were collected prospectively. Outcome after 3months was measured with the modified Rankin Scale (mRS); mRS 0-1 was considered as favorable outcome. White matter lesions were scored visually by two observers using the semiquantitative Scheltens and Fazekas scores. Logistic regression analysis was used to identify the association of white matter lesions and clinical outcome, recanalization, and cerebral hemorrhage. The severity of white matter lesions was inversely correlated with favorable outcome, survival and successful recanalization. White matter lesions were an independent predictor of outcome (OR 0.569, p=0.007) and survival (OR 0.550, p=0.018) and a weak but independent predictor for recanalization (OR 0.949, p=0.038). Asymptomatic intracerebral bleeding after IAT was associated with white matter lesions in the basal ganglia in the univariate analysis (p=0.036), but not after multivariable analysis. The severity of white matter lesions independently predicts clinical outcome and survival in patients treated with IAT. White matter lesions are also a weak but independent predictor for recanalization. Symptomatic intracranial bleeding after IAT are not associated with white matter lesions. Therefore, white matter lesions should not be considered as a contraindication against IA

Evaluation of intracranial stenting in a simulated training and assessment environment for neuroendovascular procedures

PurposeGiven the inherent complexity of neurointerventional procedures and the associated risks of ionizing radiation exposure, it is crucial to prioritize ongoing training and improve safety protocols. The aim of this study is to assess a training and evaluation in-vitro environment using a vascular model of M1 stenosis, within a clinical angiography suite, without relying on animal models or X-ray radiation.Materials and methodsUsing a transparent model replicating M1 stenosis, we conducted intracranial stenting procedures with four different setups (Gateway & Wingspan, Gateway & Enterprise, Neurospeed & Acclino, and Pharos Vitesse). A video camera was integrated with the angiography system’s monitor for real-time visualization, while a foot switch was employed to simulate live fluoroscopy. Three neuroradiologists with varying levels of expertise performed each procedure for three times. The total duration of fluoroscopy as well as the time from passing the stenosis with the wire to completion of the procedure were recorded using a dedicated software designed for this experimental setup.ResultsCompared to the Gateway & Wingspan procedure, the total fluoroscopy time reduced significantly with the Gateway & Enterprise, Neurospeed & Acclino, and Pharos Vitesse procedures by 51.56 s, 111.33 s, and 144.89 s, respectively (p < 0.001). Additionally, physicians with under 2 years and over 5 years of experience reduced FT by 62.83 s and 106.42 s, respectively, (p < 0.001), compared to a novice physician. Similar trends were noted for the time of wire distal to stenosis, with significant reductions for Neurospeed & Acclino and Pharos Vitesse compared to both Gateway & Wingspan as well as Gateway & Enterprise (all p < 0.001).ConclusionProcedures requiring wire exchange maneuvers exhibited nearly twice the fluoroscopy time in comparison to balloon-mounted stenting or stent-placement via PTA balloon catheters. The more experienced neuroradiologist demonstrated significantly quicker performance in line with expectations in a real-life clinical setting, when compared to the less experienced interventionalist. This in-vitro setup allowed the evaluation of alternative technical approaches and differences in experience of operators without the use of animal models or X-ray. The setup combines advantages of simulators and silicone vessel models in a realistic working environment

Acute Stroke: Present and Future of Catheter-Based Interventions

Acute ischemic stroke is a major cause of morbidity and mortality in industrialized nations. The sequel of stroke ranges from mild to severe disability and even death. Since the impairment may be permanent, the costs to society from work incapacity and the need for long-term care can be high. Additionally, the burden of suffering associated with the disease may have devastating effects on individuals and families.Following the occlusion of a cerebral vessel, the full extent of the infarction may not become clinically and radiologically apparent until days after. By then, the surrounding watershed zone, or penumbra, either survives or succumbs to necrosis over time. The natural history of this "tissue at risk" is determined by two factors: the collateralization from other vascular territories and the possible occurrence of spontaneous recanalization of the occluded vessel. The current treatment options for acute ischemic stroke are aiming at an early and sustained restoration of flow to the penumbra. The effect of the treatment is therefore time-dependent and the neurologic outcome is a function of the time span between onset of symptoms and recanalization therapy as well as of the recanalization rate associated with a specific treatment.This report summarizes the results of the major trials on catheter-based interventions, either using thrombolytic drugs or novel mechanical approaches being developed to treat patients with acute ischemic stroke