Publications by authors named "Michael Knauth"

Background: Flow diverters (FD) are used regularly for the endovascular treatment of unruptured intracranial aneurysms. We aimed to assess the safety and effectiveness of the Derivo embolization device (DED) with respect to long-term clinical and angiographic outcomes.

Methods: A prospective multicenter trial was conducted at 12 centers.

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Background: Delayed cerebral ischemia is one of the leading causes of death and disability in patients with subarachnoid hemorrhage (SAH). Transluminal balloon angioplasty (TBA) is a therapeutic option for vasospasms affecting proximal intracranial arteries.

Methods: Aim of this study was to report our experience using the Scepter C balloon catheter in the treatment of cerebral vasospasms due to SAH and evaluate the postprocedural result with the iFlow tool.

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Background And Purpose: Rapid thrombectomy for acute ischemic stroke caused by large vessel occlusion leads to improved outcome. Optimizing intrahospital management might diminish treatment delays. To examine if one-stop management reduces intrahospital treatment delays and improves functional outcome of acute stroke patients with large vessel occlusion.

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Background: Flat detector CT - angiography (FDCTA) has become a valuable imaging tool in post- and peri-interventional imaging after neurovascular procedures. Metal artifacts produced by radiopaque implants like clips or coils still impair image quality.

Methods: FDCTA was performed in periprocedural or follow-up imaging of 21 patients, who had received neurovascular treatment.

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Background And Purpose: Collateral status is an important factor determining outcome in acute ischemic stroke (AIS). Hence, different collateral scoring systems have been introduced. We applied different scoring systems on single- and multi-phase computed tomography (CT) angiography (spCTA and mpCTA) and compared them to CT perfusion (CTP) parameters to identify the best method for collateral evaluation in patients with AIS.

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Background: The assessment of carotid artery flow by neurovascular ultrasound (nvUS) can be complemented by real-time phase-contrast (RT-PC) flow MRI which apart from quantitative flow parameters offers velocity distributions across the entire vessel lumen.

Materials And Methods: The feasibility and diagnostic potential of RT-PC flow MRI was evaluated in 20 healthy volunteers in comparison to conventional nvUS. RT-PC flow MRI at 40 ms temporal resolution and 0.

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This manuscript describes a streamlined protocol for the management of patients with acute ischemic stroke, which aims at the minimization of time from hospital admission to reperfusion. Rapid restoration of cerebral blood flow is essential for the outcomes of patients with acute ischemic stroke. Endovascular treatment (EVT) has become the standard of care to accomplish this in patients with acute stroke due to large vessel occlusion (LVO).

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Background: Endovascular treatment (EVT) has been shown to significantly improve functional outcome in patients with acute large cerebral vessel occlusions. To date, no evidence-based recommendations on blood pressure management after successful EVT exist. Previous studies showed an association between high pre-EVT systolic blood pressure (SBP) and functional outcome, but do not answer the question on how to manage blood pressure after successful recanalization.

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Background And Purpose: Intrahospital time delays significantly affect the neurological outcome of stroke patients with large-vessel occlusion. This study was conducted to determine whether a one-stop management can reduce intrahospital times of patients with acute large-vessel occlusion.

Methods: In this observational study, we report the first 30 consecutive stroke patients imaged and treated in the same room.

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Background And Purpose: Thrombectomy has become the standard of care for acute ischaemic stroke due to large vessel occlusion. Aim of this study was to compare the radiological outcomes and time metrics of the various thrombectomy techniques.

Methods: In this retrospective, multicenter study we analysed the data of 450 patients with occlusion of the anterior circulation, treated in five high-volume center from 2013 to 2016.

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. Atrial fibrillation (AF) is an important cause of embolic stroke of undetermined source (ESUS). Imaging-patterns like multiple infarcts, simultaneous involvement of different circulations, infarcts of different ages, and isolated cortical infarcts are likely to indicate cardioembolic stroke.

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Background: There are contradictory reports concerning the validity of transcranial sonography (TCD and TCCS) for examinations of the basilar artery. Here we investigated sensitivity and specificity of transcranial sonography for the detection of basilar artery stenosis and in-stent-restenosis compared to cerebral angiography.

Methods: We analyzed data of 104 examinations of the basilar artery.

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After endovascular treatment became the standard of care procedure for acute ischaemic stroke with large artery occlusion in 2015 the number of performed interventions has increased dramatically. Especially because age is no exclusion criterion for endovascular treatment, a relevant number of patients with difficult to access carotid arteries has to be treated. In these patients a direct puncture of the carotid is a valuable tool but is associated with severe complications and an initial learning curve.

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Introduction Some of the latest groundbreaking trials suggest that noncontrast cranial computed tomography and computed tomography-angiography are sufficient tools for patient selection within six hours of symptom onset. Before endovascular stroke therapy became the standard of care, patient selection was one of the most useful tools to avoid futile reperfusions. We report the outcomes of endovascularly treated stroke patients selected with a perfusion-based paradigm and discuss the implications in the current era of endovascular treatment.

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Background: Identification of patients requiring decompressive hemicraniectomy (DH) after endovascular therapy (EVT) is crucial as clinical signs are not reliable and early DH has been shown to improve clinical outcome. The aim of our study was to identify imaging-based scores to predict the risk for space occupying ischemic stroke and DH.

Methods: Prospectively derived data from patients with acute large artery occlusion within the anterior circulation and EVT was analyzed in this monocentric study.

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Background: Endovascular techniques for treatment of large vessel occlusions (LVO) in patients with acute ischemic stroke (AIS) have advanced in recent years. We report a multicenter experience using a combined aspiration and stent retriever technique for mechanical thrombectomy (MT).

Methods: We retrospectively analyzed 32 consecutive MT patients using a novel, combined approach of Stent retriever Assisted Vacuum-locked Extraction (SAVE) by 3 operators at 3 stroke centers.

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We hereby report a novel technical approach for the treatment of acute stroke with underlying tandem occlusion. The so-called retriever wire supported carotid artery revascularization (ReWiSed CARe) technique, utilizing the wire of a stent-retriever as a guiding wire for carotid artery stenting, is technically feasible in tandem occlusions caused by an internal carotid artery (ICA) dissection or high grade ICA stenosis. This technique eliminates the need to use a long microwire in order to maintain the position inside the true lumen of a dissection.

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Endovascular treatment of acute ischemic stroke has become standard of care for patients with large artery occlusion. Early restoration of blood flow is crucial for a good clinical outcome. We introduced an interdisciplinary standard operating procedure (SOP) between neuroradiologists, neurologists and anesthesiologists in order to streamline patient management.

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Background: Although endovascular treatment for proximal cerebral vessel occlusion is very effective, it remains controversial if intravenous thrombolysis (IVT) prior to endovascular treatment is superior compared to endovascular treatment alone. In this study we compared functional outcomes and recanalization rates of endovascularly treated stroke patients with and without bridging IVT.

Methods: Patients with acute large artery occlusion within the anterior and posterior cerebral circulation eligible for intraarterial revascularization with and without prior IVT were included in this monocentric, prospective observational study.

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Objective: Many patients with stroke cannot receive intravenous thrombolysis because the time of symptom onset is unknown. We tested whether computed tomography (CT)-based quantification of water uptake in the ischemic tissue can identify patients with stroke onset within 4.5 hours, the time window of thrombolysis.

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Background And Purpose: Flat detector CT (FDCT) has been used as a peri-interventional diagnostic tool in numerous studies with mixed results regarding image quality and detection of intracranial lesions. We compared the diagnostic aspects of the latest generation FDCT with standard multidetector CT (MDCT).

Materials And Methods: 102 patients were included in our retrospective study.

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Purpose: Two recent randomized controlled trials (RCT) consistently showed superiority of aggressive medical treatment versus percutaneous transluminal angioplasty and stenting (PTAS) in patients with intracranial artery stenosis. Patients with symptomatic basilar stenosis have a higher long-term risk of recurrent stroke compared to patients with anterior circulation stenosis but no study has specifically focused on the role of PTAS in this subgroup. The aim of our study was to investigate the subgroup of patients with symptomatic basilar artery stenosis to find evidence for the feasibility of a future clinical trial.

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Background And Purpose: Thrombectomy, primarily with stent retrievers with or without adjunctive aspiration, provided clinical benefit across multiple prospective randomized trials. Whether this benefit is exclusive to stent retrievers is unclear.

Methods: THERAPY (The Randomized, Concurrent Controlled Trial to Assess the Penumbra System's Safety and Effectiveness in the Treatment of Acute Stroke; NCT01429350) was an international, multicenter, prospective, randomized (1:1), open label, blinded end point evaluation, concurrent controlled clinical trial of aspiration thrombectomy after intravenous alteplase (IAT) administration compared with intravenous-alteplase alone in patients with large vessel ischemic stroke because of a thrombus length of ≥8 mm.

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