Numerical Analysis of Blood Flow in the Vertebral Artery

1982 ◽  
Vol 104 (2) ◽  
pp. 143-147 ◽  
Author(s):  
Takayoshi Fukushima ◽  
Takehiko Azuma ◽  
Teruo Matsuzawa
Keyword(s):  
Blood Flow ◽  
Numerical Analysis ◽  
Vertebral Artery ◽  
Arterial Blood Flow ◽  
Vascular Lesions ◽  
Shear Stresses ◽  
Hemodynamic Forces ◽  
Atherosclerotic Lesions ◽  
Arterial Blood ◽  
Structure Of Flow

Abnormal hemodynamic forces associated with distortions of blood vessel lumen have been thought to play an important role in the pathogenesis of focal vascular lesions. In the vertebral artery, segments located between osseous rings are ectatic compared with those surrounded by the rings. Based on the assumption that arterial blood flow was quasi-steady, this work was undertaken to investigate the structure of flow through arterial models with one or two sinusoidal stenoses. Numerical analysis was performed by an integral-momentum method. The validity of the method was examined by comparison of experimental data so far reported with theoretical results. Velocity and wall shear stress distributions were explored in a model with two stenoses simulating a part of the vertebral artery. The ectatic segments of the vertebral artery have been known as predilection sites for atherosclerotic lesions. The present study suggested that the ectatic wall was under unstable shear stresses, the direction of which was dependent upon the magnitude of the Reynolds number.

scholarly journals EFFICACY OF FREE AUTOVENOUS TRANSPLANT IN FEMORAL-POPLITEAL BYPASS BELOW THE JOINT SPACE OF THE KNEE

2016 ◽  
Vol 175 (4) ◽  
pp. 75-79
Author(s):  
B. S. Sykovatykh ◽  
L. N. Belikov ◽  
M. B. Sykovatykh ◽  
D. V. Sidorov ◽  
M. A. Inarkhov ◽  
...  
Keyword(s):  
Blood Flow ◽  
Joint Space ◽  
Arterial Blood Flow ◽  
Control Group ◽  
Treatment Technology ◽  
Critical Ischemia ◽  
Shunt Thrombosis ◽  
Atherosclerotic Lesions ◽  
Arterial Blood

The article presents an analysis of complex examination and treatment of 60 patients with critical ischemia of the lower extremities due to atherosclerotic lesions of femoral-poplitealtibia segment. Typical traditional autovenous bypass of reverse big saphena was performed for the first (control) group of patients. The operation, which used an original technology by free autovenous transplant with collapsed valves without vein reverse, was completed for the second (experimental) group of patients. An application of original treatment technology allowed an increase of blood flow volume in the extremity in 1,5 times, an arterial blood flow - in 1,6 times, rate of microcirculation - in 1,3 times. An early postoperative complications were decreased on 23,4%, the late shunt thrombosis - on 40%. Long-term shunt passability was improved in 2,6 times and physical component of health - on 10,6%, psychological - on 4,3%. The shunt functioned in 36,7% of the first group and in 83,3% patients of the second group after two years since operation. The extremity was saved in 60% of the first group and 90% patients of the second group.

scholarly journals Flow-mediated endothelial mechanotransduction

1995 ◽  
Vol 75 (3) ◽  
pp. 519-560 ◽  
Author(s):  
P. F. Davies
Keyword(s):  
Endothelial Cells ◽  
Blood Flow ◽  
Blood Vessel ◽  
Vascular Tone ◽  
Shear Stresses ◽  
Mechanical Forces ◽  
Hemodynamic Forces ◽  
Atherosclerotic Lesions ◽  
Arterial Structure ◽  
Gene Regulatory

Mechanical forces associated with blood flow play important roles in the acute control of vascular tone, the regulation of arterial structure and remodeling, and the localization of atherosclerotic lesions. Major regulation of the blood vessel responses occurs by the action of hemodynamic shear stresses on the endothelium. The transmission of hemodynamic forces throughout the endothelium and the mechanotransduction mechanisms that lead to biophysical, biochemical, and gene regulatory responses of endothelial cells to hemodynamic shear stresses are reviewed.

scholarly journals The potential of duplex scanning in the diagnosis of pathological tortuosity of the vertebral artery

2021 ◽  
pp. 84-95
Author(s):  
H. A. Yunusov ◽  
D. D. Sultanov ◽  
A. D. Gaibov ◽  
B. U. Abduvakhido ◽  
O. Nematzoda ◽  
...  
Keyword(s):  
Blood Flow ◽  
Vertebral Artery ◽  
Vessel Diameter ◽  
Arterial Blood Flow ◽  
Duplex Scanning ◽  
Accurate Information ◽  
Vertebral Arteries ◽  
Vertebrobasilar System ◽  
Arterial Blood ◽  
Before And After

Aim. To assess the capabilities of duplex scanning and study the features of hemodynamics in the vertebral arteries before and after surgical treatment.Material and methods. The results of anatomical and circulatory characteristics of an extracranial segment of the vertebral arteries in 52 patients with various forms of pathological tortuosity were analyzed. Kinking was present in 38 patients, coiling in 8 patients, and Powers anomaly in 6 patients. There were 18 men and 34 women. The mean age of the patients was 45.6±8.7 years.Results and discussion. In all types of PT of VA with ostium stenosis, the diameter of the artery was decreased, and based on tortuosity it contributed both to the reduction and deterioration of arterial blood flow to the vertebrobasilar basin. The decrease or increase in the linear velocity of blood flow, as well as other blood flow parameters, depended on both the type of pathological tortuosity of the PA and on the vessel diameter and the value of angulation. Hypoplasia of the opposite vertebral artery also occurred in 28 patients, which resulted in impaired blood supply to the brain.Vascular examination after reconstructive surgeries resulted in normalization of the parameters of arterial circulation and cerebral perfusion. Primary vascular patency was 96.2%, restenosis was not revealed in any observation.Conclusion. Duplex scanning is a highly informative technique for both diagnosing pathological deformities of the vertebral arteries and assessing the restoration of the hemodynamics of the vertebrobasilar system after reconstructive surgery. This method provides the most accurate information on the anatomical form and localization of pathological deformities of the vertebral artery. It also allows quantitative assessment of cerebral blood flow.

Modeling Elastic Walls in Lattice Boltzmann Simulations of Arterial Blood Flow

2013 ◽  
Vol 23 (2) ◽  
Author(s):  
Xenia Descovich ◽  
Giuseppe Pontrelli ◽  
Sauro Succi ◽  
Simone Melchionna ◽  
Manfred Bammer
Keyword(s):  
Blood Flow ◽  
Lattice Boltzmann ◽  
Arterial Blood Flow ◽  
Arterial Blood ◽  
Lattice Boltzmann Simulations ◽  
Elastic Walls

scholarly journals Sustained Inflation Reduces Pulmonary Blood Flow during Resuscitation with an Intact Cord

Children ◽  
2021 ◽  
Vol 8 (5) ◽  
pp. 353
Author(s):  
Jayasree Nair ◽  
Lauren Davidson ◽  
Sylvia Gugino ◽  
Carmon Koenigsknecht ◽  
Justin Helman ◽  
...  
Keyword(s):  
Blood Flow ◽  
Perinatal Asphyxia ◽  
Arterial Blood Flow ◽  
Positive Pressure ◽  
Optimal Timing ◽  
Delayed Cord Clamping ◽  
Arterial Blood ◽  
Cord Clamping ◽  
Sustained Inflation ◽  
Near Term

The optimal timing of cord clamping in asphyxia is not known. Our aims were to determine the effect of ventilation (sustained inflation–SI vs. positive pressure ventilation–V) with early (ECC) or delayed cord clamping (DCC) in asphyxiated near-term lambs. We hypothesized that SI with DCC improves gas exchange and hemodynamics in near-term lambs with asphyxial bradycardia. A total of 28 lambs were asphyxiated to a mean blood pressure of 22 mmHg. Lambs were randomized based on the timing of cord clamping (ECC—immediate, DCC—60 s) and mode of initial ventilation into five groups: ECC + V, ECC + SI, DCC, DCC + V and DCC + SI. The magnitude of placental transfusion was assessed using biotinylated RBC. Though an asphyxial bradycardia model, 2–3 lambs in each group were arrested. There was no difference in primary outcomes, the time to reach baseline carotid blood flow (CBF), HR ≥ 100 bpm or MBP ≥ 40 mmHg. SI reduced pulmonary (PBF) and umbilical venous (UV) blood flow without affecting CBF or umbilical arterial blood flow. A significant reduction in PBF with SI persisted for a few minutes after birth. In our model of perinatal asphyxia, an initial SI breath increased airway pressure, and reduced PBF and UV return with an intact cord. Further clinical studies evaluating the timing of cord clamping and ventilation strategy in asphyxiated infants are warranted.

Incidence and risk factors of early arterial blood flow stasis during first radioembolization of primary and secondary liver malignancy using resin microspheres: an initial single-center analysis

2015 ◽  
Vol 26 (8) ◽  
pp. 2779-2789 ◽  
Author(s):  
Claus Christian Pieper ◽  
Winfried A. Willinek ◽  
Daniel Thomas ◽  
Hojjat Ahmadzadehfar ◽  
Markus Essler ◽  
...  
Keyword(s):  
Risk Factors ◽  
Blood Flow ◽  
Arterial Blood Flow ◽  
Single Center ◽  
Liver Malignancy ◽  
Arterial Blood ◽  
Resin Microspheres ◽  
Flow Stasis
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