Clinical Research Directory

Investigation of Brain Blood Flow Changes in Acute Ischemic Stroke Patients After Successful Endovascular Thrombectomy

Introduction: Endovascular thrombectomy (EVT) is an effective treatment strategy to mitigate the ischemic tissue damage caused by the acute cerebral large-vessel occlusion. However, in clinical practice, nearly half of the patients do not experience adequate neurological improvement despite successful recanalization - a phenomenon termed reperfusion failure or clinically ineffective reperfusion. Given the clinical relevance of this phenomenon and the absence of a standardized imaging diagnostic method to identify it, our project aims to explore the potential role of blood oxygenation-level dependent cerebrovascular reactivity (BOLD-CVR) as novel imaging biomarker for studying reperfusion failure. Study population: Adult patients with acute ischemic stroke of the ICA, MCA or with tandem occlusion who have undergone a successful recanalization, described as mTICI score ≥2b. Objective(s): Primary objective: to longitudinally observe blood flow changes derived from BOLD-CVR imaging following successful endovascular thrombectomy in patients with large-vessel occlusion acute ischemic stroke (LVO-AIS) during the early post-treatment phase and assess their association with clinical outcome 90 days post-EVT. Secondary objective: to compare BOLD-CVR findings with those obtained from the clinical standard dynamic susceptibility contrast (DSC) MR perfusion imaging acquired in the same examination session as well as other imaging techniques included in the standard post-treatment imaging protocol at our institution. Outcomes: Clinical outcomes: * 90-day functional outcome. * Functional outcome at hospital discharge. * Neurological deterioration during hospitalization. * Radiologically confirmed haemorrhagic transformation within the reperfused tissue. * Radiologically confirmed infarct lesion progression within the reperfused tissue. * Additionally, DSC MR perfusion imaging parameters and other standard hemodynamic imaging parameters will be considered as imaging outcomes Study design: Single-center prospective observational cohort study Measurements and procedures: Included patients will undergo a total of 3 BOLD-CVR examinations: 72 hours, 7 days, and 90 days after EVT. Participation in the final examination will mark the end of the subject's involvement in the study. Clinical outcomes will be prospectively collected as per established institutional patient management protocols: during hospitalization, at discharge, and at the cerebrovascular outpatient clinic at 3 months. Number of Participants: Target sample size: 100 patients Given the observational study design and exploratory nature of this project, no sample size calculation can be performed. The provided target sample size (N = 100) has been estimated considering the inclusion of as many consecutive subjects as possible. Study period: 2.5 years The investigators aim to enroll a target sample size of 100 patients over a period of 2.5 years. This translates to an inclusion of 3-4 patients per month, with the last three months allocated for the follow-up of the last included patients. Study Centre: Clinical Neuroscience Center, Department of Neurosurgery, University Hospital Zurich Statistical Considerations: The association between BOLD-CVR findings and clinical outcomes will be investigated using regression analyses.

Radial Versus Femoral Access For Carotid Artery Stenting

Background: For moderate to severe carotid artery atherosclerotic stenosis, in the past decades, carotid artery stenting (CAS) has been an alternative to carotid endarterectomy (CEA) for the treatment of carotid artery stenosis. The transfemoral artery (TFA) using Seldinger's technique has been the most commonly used approach for CAS. The radial artery is an ideal puncture site for cerebrovascular intervention. Studies have shown that nerve intervention through radial artery approach can complete most cerebrovascular intervention procedures, including cerebral angiography, carotid artery stent implantation, vertebral artery stent implantation, intracranial artery stent implantation, mechanical thrombectomy, aspiration, intra-arterial thrombolysis and so on. However, the current studies are based on single center small sample studies, and there has been still a lack of large sample randomized controlled experiments to verify the safety and effectiveness of CAS in transradial artery (TRA) . Objective: To evaluate the efficacy and safety of CAS via TRA in patients with carotid artery stenosis through a multicenter, prospective and randomized study. Study design: This study is a randomized, open label, multicenter, parallel controlled trial. A non-inferiority test is performed to compare the primary end point between the experimental group and the control group. The experimental group will undergo carotid stent implantation via radial artery approach, while the control group will use femoral artery approach. Study population: Adult patients with symptomatic carotid-artery stenosis ≥50% or asymptomatic stenosis ≥70%. Study outcomes: Primary end points: The incidence of death, or new-onset stroke, or myocardial infarction, or severe hemorrhage events within 30 days post-procedure Secondary end points:1.The incidence of death, or new-onset stroke, or myocardial infarction, or severe hemorrhage events within 48 hours post-procedure. 2. The incidence of death, new-onset stroke and myocardial infarction within 48 hours / 30 days post-procedure. 3. The incidence of death within 48 hours / 30 days post-procedure. 4. The incidence of new-onset stroke within 48 hours / 30 days post-procedure. 5. The incidence of myocardial infarction within 48 hours / 30 days post-procedure. 6. The incidence of severe hemorrhage events within 48 hours / 30 days post-procedure. Other end points: 1. Successful rate of cerebral angiography. 2. Successful rate of CAS. 3. Degree of patient-reported comfort. 4. Operation time. 5. NIHSS score changes within 5-7 days post-procedure. 6. mRS score score within 30 days post-procedure. Safety outcomes: 1.Occurrence of all adverse events. 2. AEs related to operation and device. 3. Incidence of adverse event of special interest.