Background: As the only arterial structure of which two main arteries merged into one, the vertebro-basilar (VA-BA) system is one of the favorite sites of cerebral atherosclerotic plaques. The aim of this study was to investigate the detailed hemodynamics characteristics in the VA-BA system.
Methods: A scale-up subject-specific flow phantom of VA-BA system was fabricated based on the computed tomography angiography (CTA) scanning images of a healthy adult. Flow fields in eight axial planes and six radial planes were measured and analyzed by using particle image velocimetry (PIV) under steady flow conditions of [Formula: see text], [Formula: see text]. A water-glycerin mixture was used as the working fluid.
Results: The flow in the current model exhibited highly three-dimensional characteristics. The confluence of VAs flow formed bimodal velocity distribution near the confluence apex. Due to the asymmetrical structural configuration, the bimodal velocity profile skewed towards left, and sharper peaks were observed under higher Reynolds condition. Secondary flow characterized by two vortices formed in the radial planes where 10 mm downstream the confluence apex and persists along the BA under both Reynolds numbers. The strength of secondary flow under [Formula: see text] is around 8% higher than that under [Formula: see text], and decayed nonlinearly along the flow direction. In addition, a low momentum recirculation region induced by boundary layer separation was observed near the confluence apex. The wall shear stress (WSS) in the recirculation area was found to be lower than 0.4 Pa. This region coincides well with the preferential site of vascular lesions in the VA-BA system.
Conclusions: This preliminary study verified that the subject-specific in-vitro experiment is capable of reflecting the detailed flow features in the VA-BA system. The findings from this study may help to expand the understanding of the hemodynamics in the VA-BA system, and further clarifying the mechanism that underlying the localization of vascular lesions.
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http://dx.doi.org/10.1186/s12938-019-0711-9 | DOI Listing |
Front Neurol
June 2024
Department of Neurosurgery, The First Affiliated Hospital of Dalian Medical University, Dalian, China.
Introduction: Neurogenic hypertension (HTN) is a type of HTN characterized by increased activity of the sympathetic nervous system. Vascular compression is one of the pathogenic mechanisms of neurogenic HTN. Despite Jannetta's solid anatomical and physiological arguments in favor of neurogenic HTN in the 1970's, the treatment for essential HTN by microvascular decompression (MVD) still lacks established selection criteria.
View Article and Find Full Text PDFInt J Surg Case Rep
September 2023
Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, Zhejiang, China. Electronic address:
Introduction And Importance: Neurofibromatosis Type 1 (NF1) is a rare autosomal dominant genetic disorder that affects multiple organs and systems, including the nervous system, integumentary system, and connective tissues. Spontaneous hemothorax occurs infrequently in patients with NF1 and is associated with high fatality rates. However, it is commonly overlooked or misdiagnosed.
View Article and Find Full Text PDFJ Neuroendovasc Ther
September 2020
Department of Neurosurgery, Kokura Memorial Hospital, Kitakyushu, Fukuoka, Japan.
Objective: Persistent primitive trigeminal artery (PPTA) is a rare condition in which a fetal carotid-basilar anastomosis persists into adulthood. PPTA aneurysms often necessitate endovascular treatment and adjunctive techniques, such as stent- or balloon-assisted techniques, are sometimes selected. This case report describes two women in their sixties with unruptured right PPTA aneurysms who underwent stent-assisted coil embolization procedures, with consideration of the anatomical features in each case.
View Article and Find Full Text PDFBiomed Eng Online
September 2019
School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore.
Background: As the only arterial structure of which two main arteries merged into one, the vertebro-basilar (VA-BA) system is one of the favorite sites of cerebral atherosclerotic plaques. The aim of this study was to investigate the detailed hemodynamics characteristics in the VA-BA system.
Methods: A scale-up subject-specific flow phantom of VA-BA system was fabricated based on the computed tomography angiography (CTA) scanning images of a healthy adult.
Interv Neurol
March 2016
Departments of Neurosurgery, Louisiana State University Health Sciences Center New Orleans, New Orleans, La., USA.
Background: Posterior circulation strokes comprise approximately 20-25% of all strokes of ischemic origin. Strokes affecting this area carry a significantly higher risk for subsequent stroke or death as compared to anterior circulation strokes. Embolic protection device (EPD) use for carotid artery stenosis has translated into percutaneous interventions of proximal vertebral artery (VA) stenosis.
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