Blood flow in the internal jugular veins during the spaceflight – Is it actually bidirectional?

2020 ◽  
Vol 25 ◽  
pp. 103-106
Author(s):  
Marian Simka ◽  
Paweł Latacz ◽  
Wojciech Redelbach
2020 ◽  
Vol 30 (7) ◽  
pp. 3890-3899
Author(s):  
Jonathan C. L. Rodrigues ◽  
Galina Strelko ◽  
Esther A. H. Warnert ◽  
Amy E. Burchell ◽  
Sandra Neumann ◽  
...  

2021 ◽  
pp. 026835552199608
Author(s):  
Marian Simka ◽  
Paweł Latacz

Objectives To determine the site and nature of altered hemodynamics in pathological internal jugular veins. Method With the use of computational fluid mechanics software we simulated blood flow in 3 D models of the internal jugular veins that exhibited different morphologies, including nozzle-like strictures in their upper parts and valves in the lower parts. Results In a majority of models with nozzle-like strictures, especially those positioned asymmetrically, abnormal flow pattern was revealed, with significant flow separation and regions with reversed flow. Abnormal valves had no significant impact on flow in a case of already altered flow evoked by stricture in upper part of the vein. Conclusions In our jugular model, cranially-located stenoses, which in clinical practice are primarily caused by external compression, cause more significant outflow impact respect to endoluminal defects and pathological valves located more caudally.


2021 ◽  
Vol 40 (4) ◽  
pp. 107-112
Author(s):  
Vitaly F. Fokin ◽  
Roman B. Medvedev ◽  
Natalia V. Ponomareva ◽  
Rodion N. Konovalov ◽  
Olga V. Lagoda ◽  
...  

Understanding age-related and functional changes in cerebral venous circulation is critical for the development of new preventive, diagnostic and therapeutic approaches to maintaining brain health in the elderly. Chronic cerebral ischemia is one of the widespread socially significant vascular diseases caused by a decrease in the level of blood circulation. To assess the role of venous outflow through the internal jugular veins in cognitive decline and neural networks in patients with chronic cerebral ischemia, 30 men and 40 women (average age 66.5 years), cognitive functions and organization of neural networks were studied at high and low levels of cerebral venous blood flow through the internal jugular veins. To assess the venous outflow, the systolic blood flow rate was measured by the internal jugular veins. A higher rate of venous outflow through internal jugular veins is associated with a more successful performance of the Luria test for verbal memory. A higher or lower blood flow rate affects the formation of neural networks of the brain. At a higher blood flow rate, the predominant areas of the resting neural networks (the passive mode network of the brain and the salient network) are localized in the frontal regions, at a low blood flow rate, the predominant neural network (frontal-parietal) is located in the left hemisphere. The state of faster and slower venous outflow forms neural networks using different neural formations that affect verbal memory. Reorganization of neural networks in this case, apparently, is the central mechanism responsible for cognitive decline in chronic cerebral ischemia (2 figs, 1 table, bibliography: 10 refs)


2018 ◽  
Vol 52 (2) ◽  
pp. 48-53
Author(s):  
T.I. Moreva ◽  
◽  
E.S. Kriushev ◽  
O.V. Moreva ◽  
O.B. Pasekova ◽  
...  

2018 ◽  
Vol 19 (5) ◽  
pp. 467-472
Author(s):  
Mauro Sergio Martins Marrocos ◽  
Thais Marques S Gentil ◽  
Fernanda de C Lima ◽  
Sandra Maria R Laranja

Purpose: Real-time ultrasound is indicated for hemodialysis catheters’ insertion in internal jugular veins. We evaluated unsuccessful implantation of short-term hemodialysis catheters in internal jugular veins using real-time ultrasound between patients with and without previous short-term catheters. Methods: Observational open-label study of unsuccessful implantation of short-term hemodialysis catheters in internal jugular veins using real-time ultrasound from July 2013 to August 2014. Results: A total of 185 procedures were compared in 122 individuals; 120 (64.86%) had previously used short-term catheters. There were 5 (8%) unsuccessful implantation among 62 catheterizations without previous short-term catheter and 41 (33.6%) among 122 with previous short-term catheter (p = 0.001 Pearson’s chi-squared, odds ratio = 5.77, 95% confidence interval = 2.15–15.50, p = 0.001). Non-progressing guidewire occurred in 2 (3.2%) of 62 patients without previous short-term catheter and in 18 (14.8%) of 122 with previous short-term catheter (p = 0.018 Pearson’s chi-squared, odds ratio = 5.19, 95% confidence interval = 1.16–23.15, p = 0.031). No difference was observed between size of the veins with or without non-progressing guidewire. All 11 cases of venous thrombosis occurred in patients who had previous short-term catheter removed due to infection. Conclusion: Previous use of short-term catheter is pivotal in the occurrence of unsuccessful implantation of short-term catheter in internal jugular veins using real-time ultrasound.


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