Aneurysm Wall Enhancement Can Predict Rupture Point in Intracranial Aneurysms With Multiple Blebs.

Background And Objectives: Ruptured aneurysms visualized by vessel wall MRI (VW-MRI) exhibit characteristic aneurysm wall enhancement (AWE). A secondary bulge of the aneurysmal wall, called a bleb, is often the site of rupture in ruptured aneurysms. We hypothesized that a higher degree of AWE would identify the rupture point in aneurysms with multiple blebs.

Computational hemodynamic analysis of the offending vertebral artery at the site of neurovascular contact in a case of hemifacial spasm associated with subclavian steal syndrome: illustrative case.

Background: Hemifacial spasm (HFS) is caused by neurovascular contact along the facial nerve's root exit zone (REZ). The authors report a rare HFS case that was associated with ipsilateral subclavian steal syndrome (SSS).

Observations: A 42-year-old man with right-sided aortic arch presented with progressing left HFS, which was associated with ipsilateral SSS due to severe stenosis of the left brachiocephalic trunk.

Incomplete stent expansion in flow-diversion treatment affects aneurysmal haemodynamics: a quantitative comparison of treatments affected by different severities of malapposition occurring in different segments of the parent artery.

Incomplete stent expansion (IncSE) is occasionally seen in flow-diversion (FD) treatment of intracranial aneurysms; however, its haemodynamic consequences remain inconclusive. Through a parametric study, we quantify the aneurysmal haemodynamics subject to different severities of IncSE occurring in different portions of the stent. Two patient cases with IncSE confirmed in vivo were studied.

Carotid web leads to new thrombus formation: computational fluid dynamic analysis coupled with histological evidence.

Carotid web has been recognized as a rare cause of ischemic stroke with high recurrence rate. We describe a 48-year-old woman with carotid web who developed embolic stroke. We obtained a fresh thrombus from the internal carotid artery when carotid endarterectomy was performed.

Enlargement of a Middle Cerebral Artery Aneurysm after Intra-Aneurysmal Embolization with Parent Artery Preservation for an Ipsilateral Large Internal Carotid Artery Aneurysm: A Case Report.

We report a 77-year-old woman with marked enlargement of a middle cerebral artery (MCA) aneurysm 4 years after the successful intra-aneurysmal embolization of an ipsilateral large internal carotid artery (ICA) aneurysm. She intially presented with right third cranial nerve palsy due to a large ICA aneurysm, 20.8 mm in diameter.

Circumferential wall enhancement in evolving intracranial aneurysms on magnetic resonance vessel wall imaging.

Objective: Recent MR vessel wall imaging studies have indicated intracranial aneurysms in the active state could show circumferential enhancement along the aneurysm wall (CEAW). While ruptured aneurysms frequently show CEAW, CEAW in unruptured aneurysms at the evolving state (i.e.

Real-World Variability in the Prediction of Intracranial Aneurysm Wall Shear Stress: The 2015 International Aneurysm CFD Challenge.

Purpose: Image-based computational fluid dynamics (CFD) is widely used to predict intracranial aneurysm wall shear stress (WSS), particularly with the goal of improving rupture risk assessment. Nevertheless, concern has been expressed over the variability of predicted WSS and inconsistent associations with rupture. Previous challenges, and studies from individual groups, have focused on individual aspects of the image-based CFD pipeline.

Multiple Aneurysms AnaTomy CHallenge 2018 (MATCH): Phase I: Segmentation.

Purpose: Advanced morphology analysis and image-based hemodynamic simulations are increasingly used to assess the rupture risk of intracranial aneurysms (IAs). However, the accuracy of those results strongly depends on the quality of the vessel wall segmentation.

Methods: To evaluate state-of-the-art segmentation approaches, the Multiple Aneurysms AnaTomy CHallenge (MATCH) was announced.

Revascularization of the anterior cerebral artery by Y-shaped superficial temporal artery interposition graft for the treatment of a de novo aneurysm arising at the site of A3-A3 bypass: technical case report.

The most frequently used option to reconstruct the anterior cerebral artery (ACA) is an ACA-ACA side-to-side anastomosis. The long-term outcome and complications of this technique are unclear. The authors report a case of a de novo aneurysm arising at the site of A3-A3 anastomosis.

Initial Clinical Experience with AView-A Clinical Computational Platform for Intracranial Aneurysm Morphology, Hemodynamics, and Treatment Management.

Background: The management of intracranial aneurysm (IA) is challenging. Clinicians often rely on varied and intuitively disparate ways of evaluating rupture risk that may only partially take into account complex hemodynamic and morphologic factors. We developed a prototype of a clinically oriented, streamlined, computational platform, AView, for rapid assessment of hemodynamics and morphometrics in clinical settings.

Circumferential Wall Enhancement on Magnetic Resonance Imaging is Useful to Identify Rupture Site in Patients with Multiple Cerebral Aneurysms.

Background: Identification of rupture sites in patients with multiple intracranial aneurysms is largely based on aneurysm size, location, and shape. Finding circumferential enhancement along the aneurysm wall (CEAW) on magnetic resonance (MR) vessel wall imaging was recently shown to be indicative of ruptured aneurysm.

Objective: To investigate the hypothesis that a higher degree of CEAW would identify the site of rupture in patients with multiple aneurysms.

Impact of bifurcation angle and inflow coefficient on the rupture risk of bifurcation type basilar artery tip aneurysms.

OBJECTIVE Risk factors for aneurysm rupture have been extensively studied, with several factors showing significant correlations with rupture status. Several studies have shown that aneurysm shape and hemodynamics change after rupture. In the present study the authors investigated a static factor, the bifurcation angle, which does not change after rupture, to understand its effect on aneurysm rupture risk and hemodynamics.

Computational Hemodynamic Analysis for the Diagnosis of Atherosclerotic Changes in Intracranial Aneurysms: A Proof-of-Concept Study Using 3 Cases Harboring Atherosclerotic and Nonatherosclerotic Aneurysms Simultaneously.

This was a proof-of-concept computational fluid dynamics (CFD) study designed to identify atherosclerotic changes in intracranial aneurysms. We selected 3 patients with multiple unruptured aneurysms including at least one with atherosclerotic changes and investigated whether an image-based CFD study could provide useful information for discriminating the atherosclerotic aneurysms. Patient-specific geometries were constructed from three-dimensional data obtained using rotational angiography.

Blood Flow Into Basilar Tip Aneurysms: A Predictor for Recanalization After Coil Embolization.

Background And Purpose: Hemodynamic forces may play a role in the recanalization of coiled aneurysms. The purpose of this study was to investigate the influence of presurgical hemodynamics on the efficacy of coil embolization for basilar tip aneurysms.

Methods: We identified 82 patients who underwent endovascular coil embolization for basilar tip aneurysms with a follow-up of >1 year.

Properties of convective delivery in spinal cord gray matter: laboratory investigation and computational simulations.

OBJECT Convection-enhanced delivery (CED) is a method for distributing small and large molecules locally into the interstitial space of the spinal cord. Delivering these molecules to the spinal cord is otherwise difficult due to the blood-spinal cord barrier. Previous research has proven the efficacy of CED for delivering molecules over long distances along the white matter tracts in the spinal cord.

The Computational Fluid Dynamics Rupture Challenge 2013--Phase II: Variability of Hemodynamic Simulations in Two Intracranial Aneurysms.

With the increased availability of computational resources, the past decade has seen a rise in the use of computational fluid dynamics (CFD) for medical applications. There has been an increase in the application of CFD to attempt to predict the rupture of intracranial aneurysms, however, while many hemodynamic parameters can be obtained from these computations, to date, no consistent methodology for the prediction of the rupture has been identified. One particular challenge to CFD is that many factors contribute to its accuracy; the mesh resolution and spatial/temporal discretization can alone contribute to a variation in accuracy.

Outflow Occlusion with Occipital Artery-Posterior Inferior Cerebellar Artery Bypass for Growing Vertebral Artery Fusiform Aneurysm with Ischemic Onset: A Case Report.

Surgical treatments should be considered for vertebral artery fusiform aneurysms, which become symptomatic due to cerebral ischemia or mass effect. Ischemic complication is one of the major problems after surgical or endovascular trapping, which is associated with unfavorable outcomes. The authors present a case with growing vertebral artery (VA) fusiform aneurysm with ischemic onset successfully treated with outflow occlusion with occipital artery-posterior inferior cerebellar artery (OA-PICA) bypass.

Relative residence time prolongation in intracranial aneurysms: a possible association with atherosclerosis.

Background: Intracranial aneurysms can have atherosclerotic wall properties that may be important in predicting aneurysm history or estimating the potential risks of surgical treatments.

Objective: To investigate hemodynamic characteristics of atherosclerotic lesions in intracranial aneurysms using computational fluid dynamics.

Methods: Intraoperative video recordings of 30 consecutive patients with an unruptured middle cerebral artery aneurysm were examined to identify atherosclerotic lesions on an aneurysm wall.

Computational simulation of convection-enhanced drug delivery in the non-human primate brainstem: a simple model predicting the drug distribution.

Objectives: Convection-enhanced delivery (CED) is a technique that delivers therapeutic agents directly and effectively into the brain parenchyma. Application of CED is now under investigation as a new treatment for various diseases. Diffuse brainstem glioma is one of the important candidates that could be targeted with CED.

Safety and feasibility of convection-enhanced delivery of nimustine hydrochloride co-infused with free gadolinium for real-time monitoring in the primate brain.

Objectives: Convection-enhanced delivery (CED) has been developed as an effective drug-delivery strategy for brain tumors. Ideally, direct visualization of the tissue distribution of drugs infused by CED would assure successful delivery of therapeutic agents to the brain tumor while minimizing exposure of the normal brain tissue. We previously showed the anti-tumor efficacy of nimustine hydrochloride (ACNU) delivered via CED against a rodent intracranial xenografted tumor model.

Ruptured aneurysm of a posterior inferior cerebellar artery communicating artery. Case report and histological findings.

A hypertensive 60-year-old man presented with a rare aneurysm arising from the posterior inferior cerebellar artery (PICA) communicating artery, manifesting as subarachnoid hemorrhage with intraventricular hemorrhage. Angiography showed a small aneurysm arising from a fine and tortuous artery interconnecting the bilateral vermian branches of distal PICAs. The right PICA was absent and its vermian territory was supplied by the left PICA through this communicating artery.

Hemodynamic analysis of growing intracranial aneurysms arising from a posterior inferior cerebellar artery.

Objective: The role of hemodynamics in the growth of intracranial aneurysms is not completely clear. We present a hemodynamic study with two adjacent unruptured aneurysms arising from one parent artery but growing in different ways. This study aimed to investigate whether there were differences in hemodynamic characteristics between the two growing aneurysms.

Local convection-enhanced delivery of chemotherapeutic agent transiently opens blood-brain barrier and improves efficacy of systemic chemotherapy in intracranial xenograft tumor model.

Recently, local chemotherapy proved its efficacy against malignant gliomas. Under the hypothesis that local delivery of chemotherapeutic agents into the brain parenchyma induce opening of the blood-brain barrier (BBB), we evaluated the opening of BBB after convection-enhanced delivery of nimustine hydrochloride into the brain parenchyma. Local convection-enhanced delivery of nimustine hydrochloride transiently opened the BBB from about 7-12 days after delivery in normal rodent brain.

Convection-enhanced delivery of a synthetic retinoid Am80, loaded into polymeric micelles, prolongs the survival of rats bearing intracranial glioblastoma xenografts.

Prognosis for the patients with glioblastoma, the most common malignant brain tumor, remains dismal. A major barrier to progress in treatment of glioblastoma is the relative inaccessibility of tumors to chemotherapeutic agents. Convection-enhanced delivery (CED) is a direct intracranial drug infusion technique to deliver chemotherapeutic agents to the central nervous system, circumventing the blood-brain barrier and reducing systemic side effects.