Ultra-high resolution CT angiography for the assessment of intracranial stents and flow diverters using photon counting detector CT.

Background: The patency of intracranial stents may not be reliably assessed with either CT angiography or MR angiography due to imaging artifacts. We investigated the potential of ultra-high resolution CT angiography using a photon counting detector (PCD) CT to address this limitation by optimizing scanning and reconstruction parameters.

Methods: A phantom with different flow diverters was used to optimize PCD-CT reconstruction parameters, followed by imaging of 14 patients with intracranial stents using PCD-CT.

Dynamic Perviousness Has Predictive Value for Clot Fibrin Content in Acute Ischemic Stroke.

Dynamic perviousness is a novel imaging biomarker, with clot density measurements at multiple timepoints to allow longer contrast to thrombus interaction. We investigated the correlations between dynamic perviousness and clot composition in the setting of acute ischemic stroke. Thirty-nine patients with large vessel occlusion (LVO) undergoing mechanical thrombectomy (MT) were analyzed.

Visualization of Intracranial Aneurysms Treated with Woven EndoBridge Devices Using Ultrashort TE MR Imaging.

Background And Purpose: Assessing the treatment success of intracranial aneurysms treated with Woven EndoBridge (WEB) devices using MRI is important in follow-up imaging. Depicting both the device configuration as well as reperfusion is challenging due to susceptibility artifacts. We evaluated the usefulness of the contrast-enhanced 3D ultrashort TE (UTE) sequence in this setting.

Dynamic Perviousness: A Novel Imaging Marker for Predicting Mechanical Thrombectomy Outcomes in Acute Ischemic Stroke.

Background: The predictive value of thrombus standard perviousness (SP) in acute ischemic stroke (AIS) for the technical success rates of mechanical thrombectomy (MT) or functional outcomes is not yet conclusive. We investigated the relationship between dynamic perviousness (DP) and revascularization results using time-dependent enhancement curve types determined with computed tomography (CT).

Methods: A retrospective analysis of 137 AIS patients was performed.

The volume of steal phenomenon is associated with neurological deterioration in patients with large-vessel occlusion minor stroke not eligible for thrombectomy.

Introduction: A significant number of patients who present with mild symptoms following large-vessel occlusion acute ischemic stroke (LVO-AIS) are currently considered ineligible for EVT. However, they frequently experience neurological deterioration during hospitalization. This study aimed to investigate the association between neurological deterioration and hemodynamic impairment by assessing steal phenomenon derived from blood oxygenation-level dependent cerebrovascular reactivity (BOLD-CVR) in this specific patient cohort.

Endovascular Embolization as a Stand-Alone Treatment of Head and Neck Paragangliomas with Long-Term Tumor Control.

Background And Purpose: The impact of therapeutic embolization as a stand-alone treatment of head and neck paragangliomas considered surgically high-risk remains insufficiently understood. The aim of this study was to investigate the procedural risks and long-term volumetric development in head and neck paragangliomas with high surgical risk following therapeutic endovascular embolization as a stand-alone treatment.

Materials And Methods: A retrospective database review of patients who underwent endovascular embolization as primary treatment for head and neck paragangliomas lacking appropriate curative treatment options at our institution (from January 2000 to February 2023) was conducted.

Dynamic Perviousness Predicts Revascularization Success in Acute Ischemic Stroke.

Background: The predictive value of thrombus perviousness in acute ischemic stroke (AIS), as measured by computed tomography (CT), has been intensively studied with conflicting results. In this study, we investigate the predictive potential of the novel concept of dynamic perviousness using three-dimensional (3D) volumetric evaluation of occlusive thrombi.

Methods: The full thrombus volume in 65 patients with a hyperdense artery sign on non-contrast CT (NCCT), who underwent mechanical thrombectomy (MT), was segmented.

Ongoing Geometric Remodeling of the Parent Artery After Flow-Diverter Stent Reconstruction in Cerebral Aneurysms: The Device Design Matters.

Objective: Configuration changes of the parent artery (PA) after flow-diverter (FD) stent reconstruction, caused by the bending force of the device, may have an additional role in aneurysm occlusion as a result of the secondary alteration of intra-aneurysmal hemodynamics related to the geometry alteration of the vessel. To determine the degree of PA deformation and aneurysm occlusion rates after deployment of 2 different types of FD.

Methods: Patients treated with 2 different designs of cobalt-chromium braid (48 and 64 wire braid) structure FD were subject to analysis.

Stent reconstruction in intracranial atherosclerotic disease related acute ischemic stroke results in high revascularization rates.

Objectives: Intracranial atherosclerotic disease (ICAD) is a major cause of large vessel occlusion (LVO) in acute ischemic stroke (AIS). Our study aimed to analyze the effect of percutaneous transluminal angioplasty and stenting (PTAS) in patients with ICAD undergoing rescue treatment in terms of functional outcome and mortality rate at 90 days and compare the results to LVO with thromboembolic origins.

Materials And Methods: A retrospective review of a mechanical thrombectomy (MT) single center database from 01/2019 to 09/2021 was carried out using chart review and angiogram analysis.

Impact of age on mechanical thrombectomy and clinical outcome in patients with acute ischemic stroke.

Background And Purpose: Mechanical thrombectomy is less effective in patients aged 80 years or older. Our goal was to better understand the impact of age in general on recanalization rates and clinical outcome.

Methods: We performed a retrospective analysis of our prospective database of adult patients with acute ischemic stroke due to large vessel occlusions, who had undergone mechanical thrombectomy between 2019 and mid-2021.

Ultra-High-Resolution Time-of-Flight MR-Angiography for the Noninvasive Assessment of Intracranial Aneurysms, Alternative to Preinterventional DSA?

Purpose: The 3D time-of-flight (TOF) magnetic resonance angiography (MRA) at 3T shows high sensitivity for intracranial aneurysms but is inferior to three-dimensional digital subtraction angiography (3D-DSA) regarding aneurysm characteristics. We applied an ultra-high-resolution (UHR) TOF-MRA using compressed sensing reconstruction to investigate the diagnostic performance in preinterventional evaluation of intracranial aneurysms compared to conventional TOF-MRA and 3D-DSA.

Methods: In this study 17 patients with unruptured intracranial aneurysms were included.

Single antiplatelet regimen in flow diverter treatment of cerebral aneurysms: The drug matters. A systematic review and meta-analysis.

Background: Hemorrhagic and thromboembolic complications (TECs) are the main concerns in the endovascular treatment of intracranial aneurysms using flow diverter devices (FDs). The clinical demand for single antiplatelet therapy (SAPT) is increasing especially with the development of devices with lower thrombogenicity profile. However, the safety of SAPT is not well established.

Single-antiplatelet regimen in ruptured cerebral blood blister and dissecting aneurysms treated with flow-diverter stent reconstruction.

Background: Flow diversion treatment of ruptured cerebral aneurysms remains challenging due to the need for double-antiplatelet therapy. We report our experience with flow-diverter stent (FDS) reconstruction with single-antiplatelet therapy of ruptured cerebral blood blister and dissecting aneurysms.

Methods: In this case series we performed a retrospective analysis of all patients with ruptured cerebral aneurysms who were treated with a phosphoryl-bonded FDS between 2019 and 2022 in a single center.

MRI in patients with implanted active devices: how to combine safety and image quality using a limited transmission field?

Objectives: Radio frequency (RF) pulses in magnetic resonance imaging (MRI) can interact with implanted devices and cause tissue damage. However, there are new devices that can safely perform measurements with liberal MRI conditions such as an RF transmission field B ≤ 2.0 μT.

Visualization of Aneurysm Healing : Enhancement Patterns and Reperfusion in Intracranial Aneurysms after Embolization on 3T Vessel Wall MRI.

Purpose: Wall enhancement of intracranial aneurysms in vessel wall magnetic resonance imaging (MRI) has been linked to aneurysm progression. The clinical significance of aneurysm enhancement after embolization has not yet been investigated. The goal of this study was to identify factors associated with aneurysm wall enhancement and reperfusion after embolization.

Influence of Thrombus Composition on Thrombectomy: ADAPT vs. Balloon Guide Catheter and Stent Retriever in a Flow Model.

Purpose:  A first-pass, direct aspiration technique and stent retrieval with a balloon guide catheter represent advanced thrombectomy techniques that are increasingly being used in the clinical routine. The purpose of this experimental study was to evaluate whether the techniques' effectiveness depended on the clot composition and to visualize the interaction between the devices and the clot.

Materials And Methods:  Erythrocyte-rich (red) and fibrin-rich (white) clots were placed into the M1-segment of the middle cerebral artery in a transparent vascular phantom with physiological architecture.

Comparison of Efficacy, Embolism Rate and Safety of Thrombectomy with Stent Retrievers in an Anterior Circulation Stroke Model.

Purpose:  Various stent retrievers differing in stent design and mechanical properties are currently available for the treatment of ischemic stroke. We conducted this in vitro study to compare the efficacy, embolism rate, and safety of commercially available stent retrievers and prototypes.

Materials And Methods:  Whole blood thrombi were produced in a Chandler loop.

Stent-thrombus interaction and the influence of aspiration on mechanical thrombectomy: evaluation of different stent retrievers in a circulation model.

Introduction: Different devices and techniques are available for endovascular treatment of ischemic stroke. In this in vitro study, we examined the stent-thrombus interaction and the influence of additional aspiration on the efficiency of mechanical thrombectomy with established stent retrievers.

Methods: Human blood thrombi were made in a Chandler loop.

Off-pump tricuspid valved stent implantation: the next step.

Objectives: Off-pump transcatheter valved stent implantation could be a treatment option for patients suffering from symptomatic tricuspid regurgitation (TR) who are classified as inoperable. In this study, we present our recent short-term results of transventricular tricuspid valved stent implantation and compare different stent types for atrial anchorage.

Methods: Fifteen pigs received a self-expandable valved stent implantation off-pump via a transventricular access.