Middle cerebral arterial bifurcation aneurysms are associated with bifurcation angle and high tortuosity

2021 ◽  
Author(s):  
Xuejing Zhang ◽  
Weili Hao ◽  
Siqin Han ◽  
Chun-Feng Ren ◽  
Lei Yang ◽  
...  
Keyword(s):  
Arterial Bifurcation ◽  
Bifurcation Angle

scholarly journals Relations between the tracheal and pulmonary trunk bifurcations

2014 ◽  
Vol 20 (2) ◽  
pp. 110-114
Author(s):  
Al. Manolakis ◽  
C. Ionescu ◽  
M. Cambrea ◽  
P. Bordei ◽  
D. Iliescu
Keyword(s):  
Ct Angiography ◽  
Acute Angle ◽  
Pulmonary Trunk ◽  
Geometric Shape ◽  
Arterial Bifurcation ◽  
Bifurcation Angle ◽  
Variable Angle ◽  
Rectangular Area ◽  
Different Levels ◽  
Tracheal Bifurcation

Abstract The bifurcation of the pulmonary trunk and trachea were followed on 52 cases being appreciated on the dissection and corrosion pieces and CT examinations, the arterial bifurcation being made under an very variable angle, its value ranging from 30-1080. In 82% of cases the tracheal bifurcation was done under an acute angle, with lower value than the arterial bifurcation angle. In 41 cases (78.85% of cases) the pulmonary trunk bifurcation is done under the bifurcation of the trachea, at a distance of between 0,4 - 2,8 cm, and in 8 patients (15.38% of the cases) the two bifurcations was located at the same level. Only in 3 cases (5.77% of cases), all on CT angiography, we encountered the pulmonary trunk bifurcation above tracheal bifurcation, with 0.3-0.8 cm, bifurcation of the pulmonary trunk being left lying of the tracheal bifurcation. In these cases, the bifurcation angle of the pulmonary trunk is always greater than the angle of the trachea bifurcation. On the dissected and the corrosion pieces is found that when the bifurcation is situated at different levels, the tracheal one being located cranial, the most commonly between them form a rectangular area: rhombus, more frequently, and rectangular or trapezium and rarely a pentagon or triangle. Any geometric shape to be formed between the two junctions, it is often asymmetric.

Effects of Arterial Bifurcation Geometry on Nucleotide Concentration at the Endothelium

2006 ◽  
Vol 34 (4) ◽  
pp. 605-617 ◽  
Author(s):  
Andrew Comerford ◽  
Tim David ◽  
Mike Plank
Keyword(s):  
Arterial Bifurcation

Mean Wall Shear Stress in the Femoral Arterial Bifurcation Is Low and Independent of Age at Rest

2000 ◽  
Vol 37 (2) ◽  
pp. 112-122 ◽  
Author(s):  
Lilian Kornet ◽  
Arnold P.G. Hoeks ◽  
Jacques Lambregts ◽  
Robert S. Reneman
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Arterial Bifurcation ◽  
Wall Shear

Blood flow and vessel mechanics in a physiologically realistic model of a human carotid arterial bifurcation

2000 ◽  
Vol 33 (8) ◽  
pp. 975-984 ◽  
Author(s):  
S.Z Zhao ◽  
X.Y Xu ◽  
A.D Hughes ◽  
S.A Thom ◽  
A.V Stanton ◽  
...  
Keyword(s):  
Blood Flow ◽  
Realistic Model ◽  
Arterial Bifurcation ◽  
Carotid Arterial ◽  
Vessel Mechanics ◽  
Human Carotid

scholarly journals Exploring the Relationships Between Hemodynamic Stresses in the Carotid Arteries

2021 ◽  
Vol 7 ◽  
Author(s):  
Magnus Ziegler ◽  
Jesper Alfraeus ◽  
Elin Good ◽  
Jan Engvall ◽  
Ebo de Muinck ◽  
...  
Keyword(s):  
Vessel Wall ◽  
Carotid Arteries ◽  
Carotid Bifurcation ◽  
Vessel Diameter ◽  
Atherosclerotic Plaques ◽  
Shear Stresses ◽  
Strongly Correlated ◽  
4D Flow ◽  
Bifurcation Angle

Background: Atherosclerosis manifests as a focal disease, often affecting areas with complex hemodynamics such as the carotid bifurcation. The magnitude and regularity of the hemodynamic shear stresses acting on the vessel wall are thought to generate risk patterns unique to each patient and play a role in the pathogenesis of atherosclerosis. The involvement of different expressions of shear stress in the pathogenesis of carotid atherosclerosis highlights the need to characterize and compare the differential impact of the various expressions of shear stress in the atherosclerotic carotid bifurcation. Therefore, the aim of this study is to characterize and compare hemodynamic wall shear stresses (WSS) in the carotid arteries of subjects with asymptomatic atherosclerotic plaques. Shear stresses were also compared against vessel diameter and bifurcation angle to examine the relationships with the geometry of the carotid bifurcation.Methods: 4D Flow MRI and contrast-enhanced MRA data were acquired for 245 subjects with atherosclerotic plaques of at least 2.7 mm in conjunction with the Swedish CArdioPulmonary bioImage Study (SCAPIS). Following automatic segmentation and geometric analysis, time-resolved WSS and near-wall turbulent kinetic energy (nwTKE) were derived from the 4D Flow data. Whole-cycle parameters including time-averaged WSS and nwTKE, and the oscillatory shear index (OSI) were calculated. Pairwise Spearman rank-correlation analyses were used to investigate relationships among the hemodynamic as well as geometric parameters.Results: One hundred and seventy nine subjects were successfully segmented using automated tools and subsequently geometric and hemodynamic analyses were performed. Temporally resolved WSS and nwTKE were strongly correlated, ρ = 0.64. Cycle-averaged WSS and nwTKE were moderately correlated, ρ = 0.57. Cycle-average nwTKE was weakly correlated to OSI (ρ = −0.273), revealing that nwTKE provides information about disturbed flow on the vessel wall that OSI does not. In this cohort, there was large inter-individual variation for both WSS and nwTKE. Both WSS and nwTKE varied most within the external carotid artery. WSS, nwTKE, and OSI were weakly correlated to vessel diameter and bifurcation angle.Conclusion: The turbulent and mean component of WSS were examined together in vivo for the first time, and a strong correlation was found between them. nwTKE presents the opportunity to quantify turbulent wall stresses in vivo and gain insight into the effects of disturbed flow on the vessel wall. Neither vessel diameter nor bifurcation angle were found to be strongly correlated to the turbulent or mean component of WSS in this cohort.

scholarly journals Induction of aneurysmogenic high positive wall shear stress gradient by wide angle at cerebral bifurcations, independent of flow rate

2019 ◽  
Vol 131 (2) ◽  
pp. 442-452 ◽  
Author(s):  
Alexandra Lauric ◽  
James E. Hippelheuser ◽  
Adel M. Malek
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Flow Rate ◽  
Stress Gradient ◽  
Dependent Manner ◽  
Parent Vessel ◽  
Spatial Gradients ◽  
Bifurcation Angle ◽  
Wall Shear ◽  
Dynamics Simulations

OBJECTIVEEndothelium adapts to wall shear stress (WSS) and is functionally sensitive to positive (aneurysmogenic) and negative (protective) spatial WSS gradients (WSSG) in regions of accelerating and decelerating flow, respectively. Positive WSSG causes endothelial migration, apoptosis, and aneurysmal extracellular remodeling. Given the association of wide branching angles with aneurysm presence, the authors evaluated the effect of bifurcation geometry on local apical hemodynamics.METHODSComputational fluid dynamics simulations were performed on parametric bifurcation models with increasing angles having: 1) symmetrical geometry (bifurcation angle 60°–180°), 2) asymmetrical geometry (daughter angles 30°/60° and 30°/90°), and 3) curved parent vessel (bifurcation angles 60°–120°), all at baseline and double flow rate. Time-dependent and time-averaged apical WSS and WSSG were analyzed. Results were validated on patient-derived models.RESULTSNarrow symmetrical bifurcations are characterized by protective negative apical WSSG, with a switch to aneurysmogenic WSSG occurring at angles ≥ 85°. Asymmetrical bifurcations develop positive WSSG on the more obtuse daughter branch. A curved parent vessel leads to positive apical WSSG on the side corresponding to the outer curve. All simulations revealed wider apical area coverage by higher WSS and positive WSSG magnitudes, with increased bifurcation angle and higher flow rate. Flow rate did not affect the angle threshold of 85°, past which positive WSSG occurs. In curved models, high flow displaced the impingement area away from the apex, in a dynamic fashion and in an angle-dependent manner.CONCLUSIONSApical shear forces and spatial gradients are highly dependent on bifurcation and inflow vessel geometry. The development of aneurysmogenic positive WSSG as a function of angular geometry provides a mechanotransductive link for the association of wide bifurcations and aneurysm development. These results suggest therapeutic strategies aimed at altering underlying unfavorable geometry and deciphering the molecular endothelial response to shear gradients in a bid to disrupt the associated aneurysmal degeneration.

scholarly journals Carina Bifurcation Angle and Side Branch Occlusion in Coronary Bifurcation Lesions Intervention: Angiographic Lesions Characteristic Role in Determining Its Relation

2018 ◽  
Vol 28 (02) ◽  
pp. 137-141 ◽  
Author(s):  
Bogie Putra Palinggi ◽  
Doni Firman
Keyword(s):  
Percutaneous Coronary Intervention ◽  
Coronary Intervention ◽  
Side Branch ◽  
Coronary Bifurcation ◽  
Cross Sectional ◽  
Bifurcation Angle ◽  
Coronary Bifurcation Lesions ◽  
Increased Risk ◽  
Percutaneous Coronary ◽  
Bifurcation Lesions

AbstractSide branch occlusion has been implicated as a complication after percutaneous coronary intervention in coronary bifurcation lesions. The role of carina bifurcation angle as one of the characteristics of the coronary bifurcation lesions in causing side branch occlusion after percutaneous coronary intervention is still debated. This study aims to assess the correlation between carina bifurcation angles as one of the characteristics of the coronary bifurcation lesions and side branch occlusion in elective percutaneous coronary intervention. This is a cross-sectional study which utilizes CAAS 5.1 software to measure carina bifurcation angle. We collected 113 lesions in 108 patients that met the inclusion criteria from January 2016 to October 2016. Side branch occlusion occurred in 15 lesions (13.3%), with median carina bifurcation angle 19.17 degrees (p < 0.001). Multivariate analysis showed there is a correlation between carina bifurcation angle with side branch occlusion, OR (odds ratio) 0.86 (95% CI [confidence interval]: 0.80–0.92) with ≤ 33.71 degrees cut off value. Increased risk of side branch occlusion was found in small carina bifurcation angle.

Sign in / Sign up

Export Citation Format

Share Document