Effects of Blood Flow on Development of Atheromatous Plaques at an Experimental Inter-Carotid Anastomosis (Model Carotid Bifurcation)

1988 ◽  
pp. 205-208
Author(s):  
M. Kashihara ◽  
S. Ueda ◽  
K. Matsumoto
Keyword(s):  
Blood Flow ◽  
Carotid Bifurcation ◽  
Atheromatous Plaques

Persistent Cervical Intersegmental Artery as a Cause of Recurrence of a Traumatic Carotid-Cavernous Fistula

Neurosurgery ◽  
1982 ◽  
Vol 10 (4) ◽  
pp. 492-498 ◽  
Author(s):  
Herbert M. Keller ◽  
Hans-Georg Imhof ◽  
Anton Valavanis
Keyword(s):  
Blood Flow ◽  
Carotid Artery ◽  
Internal Carotid Artery ◽  
Vertebral Artery ◽  
Cavernous Sinus ◽  
Internal Carotid ◽  
Flow Direction ◽  
Carotid Bifurcation ◽  
Carotid Cavernous Sinus Fistula ◽  
Increased Blood Flow

Abstract In a 16-year-old boy, minor symptoms of an arteriovenous shunt into the cavernous sinus recurred 3 months after the performance of a trapping operation of the internal carotid artery on the side of a traumatic carotid-cavernous sinus fistula. An arterial and venous cerebrovascular Doppler examination demonstrated increased blood flow in the periorbital veins of both sides, with a pathological flow direction, i.e., from intra- to extracranial. Furthermore, an internal-like artery was found at the level of the carotid bifurcation on the side of the trapped internal carotid artery, and increased blood flow was registered in the homolateral vertebral artery. Angiography confirmed occlusion of the internal carotid artery 0.5 cm distal to the carotid bifurcation, but showed blood flow from the homolateral vertebral artery through a persistent 3rd cervical intersegmental artery into the trapped portion of the internal carotid artery. The latter fed blood into the cavernous sinus through the still-existing arteriovenous fistula. Insufficient involution of the 3rd cervical intersegmental artery was assumed. Obviously, this collateral artery dilated in the presence of a major blood pressure gradient between the vertebral artery and the trapped segment of the internal carotid artery. Thus, a persistent cervical intersegmental artery can be a cause for a recurrent carotid-cavernous sinus fistula.

Relation between histological age-changes in the carotid body and atherosclerosis in the carotid arteries

1987 ◽  
Vol 101 (12) ◽  
pp. 1271-1275 ◽  
Author(s):  
Patrick Lowe ◽  
Donald Heath ◽  
Paul Smith
Keyword(s):  
Blood Flow ◽  
Carotid Body ◽  
Carotid Arteries ◽  
Carotid Sinus ◽  
Carotid Bifurcation ◽  
Age Changes ◽  
Histological Changes ◽  
Atherosclerotic Lesions ◽  
Flow Through ◽  
Human Carotid

Abstract Histological changes in the human carotid body associated with increasing age are accompanied by occlusive atherosclerotic lesions in the arteries of the carotid bifurcation, and are probably ischaemic in origin. The carotid sinus, however, is unusually susceptible to the development of atheroma and its occlusion appears to have little influence in compromising blood flow through the glomic arteries.

A Numerical Multiscale Study of the Haemodynamics in an Image-Based Model of Human Carotid Artery Bifurcation

2009 ◽  
Author(s):  
Diego Gallo ◽  
Raffaele Ponzini ◽  
Filippo Consolo ◽  
Diana Massai ◽  
Luca Antiga ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Blood Flow ◽  
Shear Stress ◽  
Wall Shear Stress ◽  
Cardiovascular System ◽  
Vessel Wall ◽  
3D Model ◽  
Carotid Bifurcation ◽  
Wall Shear ◽  
Flow Division

The initiation and progression of vessel wall pathologies have been linked to disturbances of blood flow and altered wall shear stress. The development of computational techniques in fluid dynamics, together with the increasing performances of hardware and software allow to routinely solve problems on a virtual environment, helping to understand the role of biomechanics factors in the healthy and diseased cardiovascular system and to reveal the interplay of biology and local fluid dynamics nearly intractable in the past, opening to detailed investigation of parameters affecting disease progression. One of the major difficulties encountered when wishing to model accurately the cardiovascular system is that the flow dynamics of the blood in a specific vascular district is strictly related to the global systemic dynamics. The multiscale modelling approach for the description of blood flow into vessels consists in coupling a detailed model of the district of interest in the framework of a synthetic description of the surrounding areas of the vascular net [1]. In the present work, we aim at evaluating the effect of boundary conditions on wall shear stress (WSS) related vessel wall indexes and on bulk flow topology inside a carotid bifurcation. To do it, we coupled an image-based 3D model of carotid bifurcation (local computational domain), with a lumped parameters (0D) model (global domain) which allows for physiological mimicking of the haemodynamics at the boundaries of the 3D carotid bifurcation model here investigated. Two WSS based blood-vessel wall interaction descriptors, the Time Averaged WSS (TAWSS), and the Oscillating Shear Index (OSI) were considered. A specific Lagrangian-based “bulk” blood flow descriptor, the Helical Flow Index (HFI) [2], was calculated in order to get a “measure” of the helical structure in the blood flow. In a first analysis the effects of the coupled 0D models on the 3D model are evaluated. The results obtained from the multiscale simulation are compared with the results of simulations performed using the same 3D model, but imposing a flow rate at internal carotid (ICA) outlet section equal to the maximum (60%) and the minimum (50%) flow division obtained out from ICA in the multiscale model simulation (the presence of the coupled 0D model gives variable internal/external flow division ratio during the cardiac cycle), and a stress free condition on the external carotid (ECA).

scholarly journals Reconstruction of blood flow patterns in a human carotid bifurcation: A combined CFD and MRI study

2000 ◽  
Vol 11 (3) ◽  
pp. 299-311 ◽  
Author(s):  
Quan Long ◽  
X. Yun Xu ◽  
Ben Ariff ◽  
Simon A. Thom ◽  
Alun D. Hughes ◽  
...  
Keyword(s):  
Blood Flow ◽  
Carotid Bifurcation ◽  
Flow Patterns ◽  
Mri Study ◽  
Blood Flow Patterns ◽  
Human Carotid

COMPUTATIONAL STUDY OF THE INFLUENCE OF BIFURCATION ANGLE ON HAEMODYNAMICS AND OXYGEN TRANSPORT IN THE CAROTID BIFURCATION

2019 ◽  
Vol 31 (03) ◽  
pp. 1950024 ◽  
Author(s):  
Shigeru Tada
Keyword(s):  
Blood Flow ◽  
Oxygen Transport ◽  
Computational Study ◽  
Three Dimensional ◽  
Atherosclerotic Lesion ◽  
Axial Flow ◽  
Carotid Bifurcation ◽  
Outer Wall ◽  
Flow Recirculation ◽  
Bifurcation Angle

In this study, blood flow associated with oxygen transport in the human carotid bifurcation was investigated numerically to assess the effects of bifurcation geometry on distribution and magnitude of the wall shear stress (WSS) and Sherwood number (Sh: dimensionless oxygen wall flux) at the favourable site of atherosclerotic lesion. Three-dimensional average models of the rigid-walled carotid bifurcation were constructed to perform simulations of steady blood flow under the wall boundary condition of a constant oxygen tension. The results demonstrated that changes in the bifurcation angle significantly altered the distribution of both the WSS and the Sh, even though the pattern of the axial flow was not very sensitive to the change in bifurcation angle. Flow with large inertia bifurcated at the flow divider and created a flow recirculation zone with low WSS and Sh on the outer wall of the internal carotid artery (ICA) sinus, where atherosclerotic lesions tend to develop. A wider bifurcation angle made the area of low Sh in the ICA sinus smaller, but the level of Sh along the outer wall of the ICA sinus extremely low. Another finding was that low Sh was associated with high WSS at the region distal to the ICA sinus. The Sh distribution did not readjust as fast as the WSS in this region, as reflected by the different rates of recovery of the WSS and Sh, thus uncoupling the transport process of oxygen transport from WSS.

Age-Dependent Morphological Changes of the Human Carotid Bifurcation

1999 ◽  
Author(s):  
Baruch B. Lieber ◽  
Ajay K. Wakhloo ◽  
Andreas R. Luft ◽  
Afshin A. Divani
Keyword(s):  
Blood Flow ◽  
Blood Supply ◽  
Carotid Sinus ◽  
Subsequent Development ◽  
Carotid Bifurcation ◽  
Support Pressure ◽  
Morphological Development ◽  
Sinus Wall ◽  
The Brain ◽  
Human Carotid

Abstract The development, significance and function of the human carotid sinus is not yet well understood. The arterial wall within the carotid sinus is well enervated and it contains baroreceptive neural terminals. One hypothesis that was put forward is that the dilation, which may involve all vessels of the carotid bifurcation, exists to support pressure sensing1. Another hypothesis that is supported only by phenomenological observations assume that the function of the sinus is to protect the brain by slowing blood flow and reducing pulsatility2. Yet another hypothesis interprets the sinus as an ontogenetic or phylogenic residual3. More recently, carotid hemodynamics has been investigated using in vitro and computational models. Flow patterns in the carotid sinus were found to be complex and as such have been implicated in the hetrogenesis and subsequent development of atherosclerosis at this site. However, the development of this unique sinus morphology, the role of hemodynamics in such development, and the physiological implications created by this unique morphology have not been investigated. Understanding the hemodynamic and developmental forces that play a role in remodeling of the carotid bifurcation and development of the sinus is of both fundamental and clinical interest and can lead to better prognostication and therapy of carotid disease. Therefore, we initiated a study of the morphological development of the human carotid bulb using different age groups under the hypothesis that sinus morphology reflects an adaptive change in response to alterations in cerebral blood supply during the developmental years of the brain. This adaptation attempts to reduce hydraulic losses in the carotid bifurcation through reduced flow disturbances and maintain high level of blood supply to the brain than consumes about 15% of cardiac output under basal conditions. In addition, it may protect the sinus wall from high shear stress and/or the brain from highly pulsatile blood flow conditions. Initially, we analyzed the angle and sinus morphology of the carotid bifurcation in pediatric and adult patients using biplane digital subtraction angiograms to characterize changes that occur as the brain matures.

Eugene Strandness and the development of Doppler ultrasound in vascular disease

2011 ◽  
Author(s):  
David S. Sumner ◽  
Kirk w. Beach
Keyword(s):  
Blood Flow ◽  
Carotid Bifurcation ◽  
Football Player ◽  
Arterial Disease ◽  
The United States ◽  
Aortic Aneurysms ◽  
Young Surgeon ◽  
The Korean War ◽  
Exciting Time ◽  
The 1960S

This is the story of how a young surgeon, Donald Eugene Strandness Jr (Gene) was instrumental in the development of the Doppler ultrasonic flow meter, which evolved into the duplex scanner — perhaps the most versatile instrument in the modern vascular lab. He was born in Bowman, North Dakota, in 1928, and attended high school in Olympia, washington, where he was a football player and a star gymnast. He graduated from Pacific Lutheran University in 1946, studied medicine at the University of washington (Uw), and in 1950 entered the general surgical residency programme. At the time of the Korean war, Gene was drafted out of his residency; met his 2-year service obligation to the United States Air Force; and in 1959 returned to Seattle, where he hoped to join in the extensive research underway on the gastrointestinal system under the direction of Professor Henry Harkins. Instead, Dr Harkins urged him to change directions and join a small group at the Seattle VA Hospital who were investigating arterial disease. This group included John Bell, Hub Radke, and J.E. Jesseph. Strandness, swallowing his initial disappointment at having to give up gastrointestinal research, quickly embraced the vascular challenge. The 1950s were a particularly exciting time in the history of vascular surgery. Improved sutures, grafts, and anaesthesia made it possible for the first time to perform major arterial surgery, such as resection of abdominal aortic aneurysms, endarterectomy of the carotid bifurcation, and bypass of iliac, femoral, and popliteal arteries. In preparation for major arterial surgery, the need for imaging was keenly felt. Physiological studies to select patients for surgery took a backseat to arteriograms and physical examination — in part because pulse palpation and patient testimony were the only methods readily available for measuring preoperative functional impairment or postoperative success. Invasive methods for studying blood flow were limited to electromagnetic flowmetry, which was performed in the operating room with the patient anaesthetized. No effort was made to duplicate normal physiological conditions. Prior to the 1960s, a few surgeons and internists maintained rudimentary vascular labs where systolic blood pressure and blood flow were measured plethysmographically.

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