Spontaneous resolution of nontraumatic bilateral Barrow Type D indirect carotid-cavernous fistulas: A case report.

A Caucasian man in his 60s with a history of Cognard Type IIB dural arteriovenous fistula presented to the emergency room with right eye proptosis, chemosis, hyperemia, epiphora, diplopia, and blurred vision. Magnetic resonance imaging and magnetic resonance angiography revealed spontaneous, bilateral Barrow Type D carotid-cavernous fistulas (CCFs) that were later confirmed through cerebral angiography. The patient had no history of head or ocular trauma.

Rist Guide Catheter for Endovascular Procedures: Initial Case Series from a Single Center.

Background: The transradial approach (TRA) for endovascular procedures has become a frequent practice in neurointervention. Advantages of the TRA include less access-site complications, early ambulation, and less postprocedural pain. The Rist 079 radial access guide catheter (Medtronic) is the first device designed specifically for neurointerventions performed through the TRA.

Predicting flow diverter sizing using the AneuGuide software: a validation study.

Background: Stent sizing remains a challenging task for flow diverter implantation because of stent foreshortening. In this study, we aimed to quantify the change in length after implantation and assess the error in length prediction using AneuGuide software.

Methods: In a retrospective cohort of 101 patients with 102 aneurysms undergoing treatment with a pipeline embolization device (PED; Covidien, Irvine, California, USA), we used AneuGuide software to obtain measured lengths (ML) and calculated lengths (CL) after stent implantation.

Comparison of stent retriever thrombectomy using 3-dimensional patient-specific models of intracranial circulation with actual middle cerebral artery occlusion thrombectomy cases.

Background And Purpose: Stent retriever (SR) thrombectomy is commonly used for the treatment of emergent large vessel occlusion (ELVO) in acute ischemic stroke. Clot imaging parameters such as clot length, diameter, distance to the internal carotid artery terminus, and vessel angle where the SR is deployed may predict the likelihood of achieving first pass effect (FPE). Most of the proposed factors that seem to affect recanalization success have been studied individually, and conflicting data derived from clinical versus in vitro studies using 3-dimensional printed models of intracranial circulation currently exist.

First U.S. Experience Using the Pipeline Flex Embolization Device with Shield Technology for Treatment of Intracranial Aneurysms.

Background: The Pipeline Flex Embolization Device with Shield technology (PED-Shield [Medtronic, Dublin, Ireland]) is a third-generation flow diverter. Surface modification of the mesh with phosphorylcholine covalently bound to the metal struts aims to reduce thrombogenicity. In the present study, we report the results from the first U.

Realistic computer modelling of stent retriever thrombectomy: a hybrid finite-element analysis-smoothed particle hydrodynamics model.

Stent retriever thrombectomy is a pre-eminent treatment modality for large vessel ischaemic stroke. Simulation of thrombectomy could help understand stent and clot mechanics in failed cases and provide a digital testbed for the development of new, safer devices. Here, we present a novel, thrombectomy method using a hybrid finite-element analysis (FEA) and smoothed particle hydrodynamics (SPH).

Artificial Intelligence for Large-Vessel Occlusion Stroke: A Systematic Review.

Background: Optimal outcomes after large-vessel occlusion (LVO) stroke are highly dependent on prompt diagnosis, effective communication, and treatment, making LVO an attractive avenue for the application of artificial intelligence (AI), specifically machine learning (ML). Our objective is to conduct a systematic review to describe existing AI applications for LVO strokes, delineate its effectiveness, and identify areas for future AI applications in stroke treatment and prognostication.

Methods: A systematic review was conducted by searching the PubMed, Embase, and Scopus databases.

Aneurysm risk metrics and hemodynamics are associated with greater vessel wall enhancement in intracranial aneurysms.

Vessel wall enhancement (VWE) in contrast-enhanced magnetic resonance imaging (MRI) is a potential biomarker for intracranial aneurysm (IA) risk stratification. In this study, we investigated the relationship between VWE features, risk metrics, morphology and hemodynamics in 41 unruptured aneurysms. We reconstructed the IA geometries from MR angiography and mapped pituitary stalk-normalized MRI intensity on the aneurysm surface using an in-house tool.

Mechanical thrombectomy versus intravenous alteplase alone in acute isolated posterior cerebral artery occlusion: a systematic review.

Background: Acute isolated posterior cerebral artery occlusions (aPCAOs) were excluded or under-represented in major randomized trials of mechanical thrombectomy (MT). The benefit of MT in comparison to intravenous tissue plasminogen activator (alteplase; IV-tPA) alone in these patients remains controversial and uncertain.

Methods: We performed a systematic search of PubMed, MEDLINE, and EMBASE databases for articles comparing MT with or without bridging IV-tPA and IV-tPA alone for aPCAO using keywords ('posterior cerebral artery', 'thrombolysis' and 'thrombectomy') with Boolean operators.

Cerebral aneurysm flow diverter modeled as a thin inhomogeneous porous medium in hemodynamic simulations.

Rapid and accurate simulation of cerebral aneurysm flow modifications by flow diverters (FDs) can help improving patient-specific intervention and predicting treatment outcome. However, when FD devices are explicitly represented in computational fluid dynamics (CFD) simulations, flow around the stent wires must be resolved, leading to high computational cost. Classic porous medium (PM) methods can reduce computational expense but cannot capture the inhomogeneous FD wire distribution once implanted on a cerebral artery and thus cannot accurately model the post-stenting aneurysmal flow.

Isolation of RNA from Acute Ischemic Stroke Clots Retrieved by Mechanical Thrombectomy.

Mechanical thrombectomy (MT) for large vessel acute ischemic stroke (AIS) has enabled biologic analyses of resected clots. While clot histology has been well-studied, little is known about gene expression within the tissue, which could shed light on stroke pathophysiology. In this methodological study, we develop a pipeline for obtaining useful RNA from AIS clots.

An Image-Based Workflow for Objective Vessel Wall Enhancement Quantification in Intracranial Aneurysms.

Background: VWE in contrast-enhanced magnetic resonance imaging (MRI) is a potential biomarker for the evaluation of IA. The common practice to identify IAs with VWE is mainly based on a visual inspection of MR images, which is subject to errors and inconsistencies. Here, we develop and validate a tool for the visualization, quantification and objective identification of regions with VWE.

Revascularization Outcome Prediction for A Direct Aspiration-First Pass Technique (ADAPT) from Pre-Treatment Imaging and Machine Learning.

A direct aspiration-first pass technique (ADAPT) has recently gained popularity for the treatment of large vessel ischemic stroke. Here, we sought to create a machine learning-based model that uses pre-treatment imaging metrics to predict successful outcomes for ADAPT in middle cerebral artery (MCA) stroke cases. In 119 MCA strokes treated by ADAPT, we calculated four imaging parameters-clot length, perviousness, distance from the internal carotid artery (ICA) and angle of interaction (AOI) between clot/catheter.

Use of patient specific 3D printed neurovascular phantoms to simulate mechanical thrombectomy.

Background: The ability of the patient specific 3D printed neurovascular phantoms to accurately replicate the anatomy and hemodynamics of the chronic neurovascular diseases has been demonstrated by many studies. Acute occurrences, however, may still require further development and investigation and therefore we studied acute ischemic stroke (AIS). The efficacy of endovascular procedures such as mechanical thrombectomy (MT) for the treatment of large vessel occlusion (LVO), can be improved by testing the performance of thrombectomy devices and techniques using patient specific 3D printed neurovascular models.

Automated Collateral Flow Assessment in Patients with Acute Ischemic Stroke Using Computed Tomography with Artificial Intelligence Algorithms.

Background: Collateral circulation is associated with improved functional outcome in patients with large vessel occlusion acute ischemic stroke (AIS) who undergo reperfusion therapy. Assessment of collateral flow can be time consuming, subjective, and difficult because of complex neurovasculature. This study assessed the ability of multiple artificial intelligence algorithms in determining collateral flow of patients with AIS.

Compliant vascular models 3D printed with the Stratasys J750: a direct characterization of model distensibility using intravascular ultrasound.

Purpose: The purpose of this study is to evaluate biomechanical accuracy of 3D printed anatomical vessels using a material jetting printer (J750, Stratasys, Rehovot, Israel) by measuring distensibility via intravascular ultrasound.

Materials And Methods: The test samples are 3D printed tubes to simulate arterial vessels (aorta, carotid artery, and coronary artery). Each vessel type is defined by design geometry of the vessel inner diameter and wall thickness.

Aberrant Whole Blood Gene Expression in the Lumen of Human Intracranial Aneurysms.

The rupture of an intracranial aneurysm (IA) causes devastating hemorrhagic strokes. Yet, most IAs remain asymptomatic and undetected until they rupture. In the search for circulating biomarkers of unruptured IAs, we previously performed transcriptome profiling on whole blood and identified an IA-associated panel of 18 genes.

Use of a sheathless 8-French balloon guide catheter (Walrus) through the radial artery for mechanical thrombectomy: technique and case series.

Background: The effectiveness of transradial stroke thrombectomy has been limited by guide catheter size and lack of good balloon options. In this study we describe our technique for the use of a sheathless 8-French balloon guide catheter (Walrus) through radial access and present our initial clinical experience.

Methods: This was a retrospective case series of consecutive patients who underwent mechanical thrombectomy for large vessel occlusion using the sheathless catheter over a period of 3 months.

RNA Sequencing Data from Human Intracranial Aneurysm Tissue Reveals a Complex Inflammatory Environment Associated with Rupture.

Background: Intracranial aneurysm (IA) rupture leads to deadly subarachnoid hemorrhages. However, the mechanisms leading to rupture remain poorly understood. Altered gene expression within IA tissue is linked to the pathobiology of aneurysm development and progression.

Identification of intima-to-media signals for flow-induced vascular remodeling using correlative gene expression analysis.

Changes in blood flow can induce arterial remodeling. Intimal cells sense flow and send signals to the media to initiate remodeling. However, the nature of such intima-media signaling is not fully understood.

Comparison of skin dose calculated by the dose tracking system (DTS) with a beam angular correction factor and that calculated by Monte-Carlo.

Skin dose is dependent on the incident beam angle and corrections are needed for accurate estimation of the risk of deterministic effects of the skin. Angular-correction factors (ACF) were calculated and incorporated into our skin-dose-tracking system (DTS) and the results compared to Monte-Carlo simulations for a neuro-interventional procedure. To obtain the ACF's, EGSnrc Monte-Carlo (MC) software was used to calculate the dose averaged over 0.

The Aneurysm Occlusion Assistant, an AI platform for real time surgical guidance of intracranial aneurysms.

Purpose: In recent years, endovascular treatment has become the dominant approach to treat intracranial aneurysms (IAs). Despite tremendous improvement in surgical devices and techniques, 10-30% of these surgeries require retreatment. Previously, we developed a method which combines quantitative angiography with data-driven modeling to predict aneurysm occlusion within a fraction of a second.

Evaluation of challenges and limitations of mechanical thrombectomy using 3D printed neurovascular phantoms.

The mechanical thrombectomy (MT) efficacy, for large vessel occlusion (LVO) treatment in patients with stroke, could be improved if better teaching and practicing surgical tools were available. We propose a novel approach that uses 3D printing (3DP) to generate patient anatomical vascular variants for simulation of diverse clinical scenarios of LVO treated with MT. 3DP phantoms were connected to a flow loop with physiologically relevant flow conditions, including input flow rate and fluid temperature.

Estimation of Patient Eye-Lens Dose During Neuro-Interventional Procedures using a Dense Neural Network (DNN).

The patient's eye-lens dose changes for each projection view during fluoroscopically-guided neuro-interventional procedures. Monte-Carlo (MC) simulation can be done to estimate lens dose but MC cannot be done in real-time to give feedback to the interventionalist. Deep learning (DL) models were investigated to estimate patient-lens dose for given exposure conditions to give real-time updates.