Vascular stenosis is often described only by its percentage in both clinical and scientific praxis. Previous studies gave inconclusive results regarding the effect of stenosis eccentricity on its hemodynamic effect. The aim of this experimental study was to investigate and quantify the effect of stenosis severity and eccentricity on the pressure drop. A combination of pressure and flow measurements by Particle Imaging Velocimetry (PIV) method was used. Models of the same stenosis significance but with different levels of eccentricity were studied in vitro by PIV. This study has shown that stenosis asymmetry is associated with more profound pressure drop and flow volume decrease. On the contrary, pressure drop and flow volume decrease were not further significantly influenced by the level of asymmetry. Hemodynamic changes associated with stenosis eccentricity must be taken into account in both clinical and scientific studies.
- MeSH
- hydrodynamika * MeSH
- lidé MeSH
- modely kardiovaskulární * MeSH
- nemoci cév * MeSH
- rychlost toku krve * MeSH
- tlak * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Stenosis is the most frequent vascular access complication and is responsible for access thrombosis and thus long-term patency limitation. Regular arteriovenous graft (AVG) examination by ultrasonography and preemptive balloon angioplasty prolong AVG cumulative patency according to some, but by far not all trials. This was why the routine use of ultrasound surveillance is not recommended recently.In this review we show huge differences in the definition of stenosis significance among the trials and other probable factors, which may have caused the contradiction of the results. Without precise definition of stenosis significance, many AVGs have been undergoing unnecessary balloon interventions with high morbidity, high cost and low benefit.
- MeSH
- arteriovenózní zkrat škodlivé účinky MeSH
- cévy - implantace protéz škodlivé účinky MeSH
- dialýza ledvin * MeSH
- duplexní dopplerovská ultrasonografie * MeSH
- lidé MeSH
- okluze cévního štěpu etiologie patofyziologie ultrasonografie MeSH
- prediktivní hodnota testů MeSH
- průchodnost cév MeSH
- regionální krevní průtok MeSH
- rychlost toku krve MeSH
- trombóza etiologie patofyziologie ultrasonografie MeSH
- výsledek terapie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
Decrease of arterial wall shear stress (WSS) is associated with higher probability of atherosclerotic plaque development in many disease conditions. End-stage renal diseases (ESRD) patients suffer from vascular disease frequently, but its nature differs from general population. This study was aimed at proving an association between common carotid wall shear stress and the presence of carotid bifurcation plaques in a group of ESRD patients. ESRD subjects, planned for the creation of a dialysis access and therapy were included. Wall shear rate (WSR) was used as a surrogate of WSS and was analyzed in the common carotid arteries by duplex ultrasonography. Intima media thickness (IMT) was measured at the same site. The presence/absence of carotid bifurcation plaques was recorded. The endothelial function was estimated by the levels of von Willebrand factor (vWf). 35 ESRD patients were included (19 females, 17 diabetics). Atherosclerotic plaque was present in 53 % of bifurcations. Wall shear rate was lower in arteries with plaques (349+/-148 vs. 506+/-206 s(-1), p=0.005) and was directly related to the height of IMT and inversely to the activity of vWf (r= -0.65, p=0.016). Lower wall shear rate in the common carotid arteries is linked to the endothelial dysfunction and to the presence of atherosclerotic plaques in carotid bifurcations in ESRD subjects. Faster arterial dilatation may facilitate this process in ESRD subjects.
- MeSH
- arteria carotis communis patofyziologie ultrasonografie MeSH
- chronické selhání ledvin komplikace patofyziologie ultrasonografie MeSH
- intimomediální šíře tepenné stěny MeSH
- lidé středního věku MeSH
- lidé MeSH
- mechanický stres MeSH
- nemoci arterie carotis komplikace patofyziologie MeSH
- senioři MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- MeSH
- lékařství MeSH
- psychiatrie MeSH
- významné osobnosti MeSH
- Publikační typ
- biografie MeSH
- portréty MeSH
- O autorovi
- Janský, Jan, 1873-1921 Autorita
- MeSH
- dějiny lékařství MeSH
- dějiny MeSH
- odměny a ceny dějiny MeSH
- významné osobnosti dějiny MeSH
- Publikační typ
- přehledy MeSH
Vyd. 1 2 sv. ; 24 cm
- Konspekt
- Lékařské vědy. Lékařství
- NLK Obory
- dějiny lékařství
- lékařství
- NLK Publikační typ
- biografické slovníky
- O autorovi
- Univerzita Karlova. Lékařská fakulta Autorita
- MeSH
- dějiny lékařství MeSH
- dějiny MeSH
- urologie dějiny MeSH
- Geografické názvy
- Československo MeSH
