Targeted Particle Tracking in Computational Models of Human Carotid Bifurcations

2011 ◽  
Vol 133 (12) ◽  
Author(s):  
Ian Marshall
Keyword(s):  
Healthy Volunteer ◽  
Carotid Artery ◽  
Flow Region ◽  
Carotid Bifurcation ◽  
Flow Patterns ◽  
External Carotid ◽  
Complex Flow ◽  
Imaging Science ◽  
Carotid Bulb ◽  
Human Carotid

A significant and largely unsolved problem of computational fluid dynamics (CFD) simulation of flow in anatomically relevant geometries is that very few calculated pathlines pass through regions of complex flow. This in turn limits the ability of CFD-based simulations of imaging techniques (such as MRI) to correctly predict in vivo performance. In this work, I present two methods designed to overcome this filling problem, firstly, by releasing additional particles from areas of the flow inlet that lead directly to the complex flow region (“preferential seeding”) and, secondly, by tracking particles both “downstream” and “upstream” from seed points within the complex flow region itself. I use the human carotid bifurcation as an example of complex blood flow that is of great clinical interest. Both idealized and healthy volunteer geometries are investigated. With uniform seeding in the inlet plane (in the common carotid artery (CCA)) of an idealized bifurcation geometry, approximately half the particles passed through the internal carotid artery (ICA) and half through the external carotid artery. However, of those particles entering the ICA, only 16% passed directly through the carotid bulb region. Preferential seeding from selected regions of the CCA was able to increase this figure to 47%. In the second method, seeding of particles within the carotid bulb region itself led to a very high proportion (97%) of pathlines running from CCA to ICA. Seeding of particles in the bulb plane of three healthy volunteer carotid bifurcation geometries led to much better filling of the bulb regions than by particles seeded at the inlet alone. In all cases, visualization of the origin and behavior of recirculating particles led to useful insights into the complex flow patterns. Both seeding methods produced significant improvements in filling the carotid bulb region with particle tracks compared with uniform seeding at the inlet and led to an improved understanding of the complex flow patterns. The methods described may be combined and are generally applicable to CFD studies of fluid and gas flow and are, therefore, of relevance in hemodynamics, respiratory mechanics, and medical imaging science.

scholarly journals Choice of In Vivo Versus Idealized Velocity Boundary Conditions Influences Physiologically Relevant Flow Patterns in a Subject-Specific Simulation of Flow in the Human Carotid Bifurcation

2008 ◽  
Vol 131 (2) ◽  
Author(s):  
Amanda K. Wake ◽  
John N. Oshinski ◽  
Allen R. Tannenbaum ◽  
Don P. Giddens
Keyword(s):  
Carotid Artery ◽  
Boundary Conditions ◽  
Carotid Bifurcation ◽  
Flow Patterns ◽  
Flow Data ◽  
Measured Velocity ◽  
Carotid Artery Bifurcation ◽  
Subject Specific ◽  
Human Carotid

Accurate fluid mechanics models are important tools for predicting the flow field in the carotid artery bifurcation and for understanding the relationship between hemodynamics and the initiation and progression of atherosclerosis. Clinical imaging modalities can be used to obtain geometry and blood flow data for developing subject-specific human carotid artery bifurcation models. We developed subject-specific computational fluid dynamics models of the human carotid bifurcation from magnetic resonance (MR) geometry data and phase contrast MR velocity data measured in vivo. Two simulations were conducted with identical geometry, flow rates, and fluid parameters: (1) Simulation 1 used in vivo measured velocity distributions as time-varying boundary conditions and (2) Simulation 2 used idealized fully-developed velocity profiles as boundary conditions. The position and extent of negative axial velocity regions (NAVRs) vary between the two simulations at any given point in time, and these regions vary temporally within each simulation. The combination of inlet velocity boundary conditions, geometry, and flow waveforms influences NAVRs. In particular, the combination of flow division and the location of the velocity peak with respect to individual carotid geometry landmarks (bifurcation apex position and the departure angle of the internal carotid) influences the size and location of these reversed flow zones. Average axial wall shear stress (WSS) distributions are qualitatively similar for the two simulations; however, instantaneous WSS values vary with the choice of velocity boundary conditions. By developing subject-specific simulations from in vivo measured geometry and flow data and varying the velocity boundary conditions in otherwise identical models, we isolated the effects of measured versus idealized velocity distributions on blood flow patterns. Choice of velocity distributions at boundary conditions is shown to influence pathophysiologically relevant flow patterns in the human carotid bifurcation. Although mean WSS distributions are qualitatively similar for measured and idealized inlet boundary conditions, instantaneous NAVRs differ and warrant imposing in vivo velocity boundary conditions in computational simulations. A simulation based on in vivo measured velocity distributions is preferred for modeling hemodynamics in subject-specific carotid artery bifurcation models when studying atherosclerosis initiation and development.

scholarly journals Variations in the Branching Pattern of External Carotid Artery in South Kerala Population – A Cadaveric Study

2021 ◽  
Vol 8 (22) ◽  
pp. 1780-1785
Author(s):  
Manju Sudhakaran ◽  
Mini Alikunju ◽  
Vandana Latha Raveendran ◽  
Umesan Kannanvilakom Govindapillai
Keyword(s):  
Carotid Artery ◽  
Head And Neck ◽  
Carotid Arteries ◽  
Carotid Bifurcation ◽  
External Carotid Artery ◽  
External Carotid ◽  
Superior Thyroid Artery ◽  
South Indian Population ◽  
Branching Pattern ◽  
South Indian

BACKGROUND External carotid arteries account for a major share of arterial supply of head and neck regions. As variations are frequently observed in the branching pattern of external carotid artery, surgeons, radiologists and anaesthetists often encounter difficulties in various procedures of head and neck. The purpose of this study is to describe the variations in the branching pattern of external carotid artery as observed in South Indian population which definitely reduces its iatrogenic injuries associated with surgical and radiological procedures of head and neck. METHODS This is cross-sectional descriptive study. Bilateral neck dissection was done on twenty-two formalin fixed cadavers to study the branching pattern of external carotid artery during a period of two years in the Department of Anatomy in Government Medical College, Alappuzha. Common carotid, external carotid and internal carotid arteries were dissected. All the branches of external carotid artery were traced and the variations were noted. The distance between carotid bifurcation and point of origin of individual branches of external carotid were measured and statistically analyzed. RESULTS In the present study along with normal branching pattern of external carotid artery, variations like origin of superior thyroid artery from common carotid artery and also from carotid bifurcation were seen. A common linguofacial trunk and direct origin of superior laryngeal artery from external carotid artery were also observed. CONCLUSIONS Prior knowledge of the variations will be helpful to surgeons and anaesthetists while dealing with these vessels during procedures of head and neck regions. KEYWORDS External Carotid Artery, Carotid Bifurcation, Superior Thyroid Artery, Linguofacial Trunk

scholarly journals Assessment of Carotid Body Tumor by Superb Micro-Vascular Imaging in a Preoperative Evaluation

2020 ◽  
Author(s):  
Luying Gao ◽  
Xiaoyan Zhang ◽  
Yuxin Jiang ◽  
Hongyan Wang ◽  
Wanying Li ◽  
...  
Keyword(s):  
Blood Flow ◽  
Carotid Artery ◽  
Carotid Body ◽  
Flow Patterns ◽  
Carotid Body Tumor ◽  
Vascular Imaging ◽  
External Carotid ◽  
Accurate Information ◽  
Feeding Artery ◽  
Blood Flow Patterns

Abstract Background: Superb micro-vascular imaging (SMI) provided new advances in vascular imaging, resulting in revealing the overall vascularity detection of small or microflow states without the use of contrast media. This study aimed to explore the blood supply andfeeding artery of carotid body tumor (CBT) on SMI for providing more accurate information for surgery.Results: Twenty-six CBT lesions underwent color Doppler flow imaging (CDFI) and SMI, and were confirmed later by pathology. The blood flow patterns and feeding artery of CBTson CDFI and SMI were graded and compared.Compared with the application of CDFI, the pattern of more CBT lesionschanged to a higher Adler category by SMI (P<0.001). Thefeeding artery of two CBT lesions, which fail to show by CDFI, was internal carotid artery(ICA) by SMI and compared with CDFI the feeding artery of three changed from ICA or external carotid artery(ECA) to MIX (both ICA and ECA) by SMI. We classified the feeding artery of CBTs into originating from ICA or others (including ECA and MIX). For all the lesions, threelesions that stemmed from ICA and 23lesions that stemmed from ECAor MIX. CBT lesions stemming from ECA or MIX with Adler II or Adler III blood flow patterns accounted for 30.4% (7/23) or 69.6% (16/23), respectively, while CBT lesions stemming from ICA with Adler I or Adler II blood flow patterns accounted for 66.7% (2/3) or 33.3% (1/3), respectively. Conclusions: SMI is superior to CDFI in detecting vascularity of CBTs, and SMI could better investigate the origin of feeding vessels of CBTs in comparison to CDFI.Compared with those originating from ECA, CBTs from ICA has less vascularity.

scholarly journals Intravascular Endothelin-1 does not trigger or increase susceptibility to Spreading Depolarizations

2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Kazutaka Sugimoto ◽  
Andreia Morais ◽  
Homa Sadeghian ◽  
Tao Qin ◽  
David Y. Chung ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Carotid Artery ◽  
Carotid Bifurcation ◽  
External Carotid Artery ◽  
External Carotid ◽  
Sprague Dawley ◽  
Vascular Events ◽  
Endothelin 1 ◽  
Pathological Conditions ◽  
Potent Vasoconstrictor

Abstract Objectives Spreading depolarizations (SD) likely manifest as aura in migraineurs. Triggers are unknown although vascular events have been implicated. Direct carotid puncture has been reported to trigger migraine with aura. The potent vasoconstrictor endothelin-1 (ET-1), which can be released from the endothelium under pathological conditions, may play a role. Here, we tested whether intracarotid ET-1 infusion triggers SD and whether systemic ET-1 infusion increases the susceptibility to SD. Methods Carotid infusions were performed in mice (C57BL/6, male) through a catheter placed at the carotid bifurcation via the external carotid artery. Intracarotid ET-1 (1.25 nmol/ml) was infused at various rates (2–16 μl/min) with or without heparin in the catheter and compared with vehicle infusion (PBS with 0.01% acetic acid) or sham-operated mice (n = 5). Systemic infusions ET-1 (1 nmol/kg, n = 7) or vehicle (n = 7) infusions were performed in rats (Sprague-Dawley, male) via the tail vein. Electrical SD threshold and KCl-induced SD frequency were measured after the infusion. Results Intracarotid infusion of saline (n = 19), vehicle (n = 7) or ET-1 (n = 12) all triggered SDs at various proportions (21%, 14% and 50%, respectively). These were often associated with severe hypoperfusion prior to SD onset. Heparinizing the infusion catheter completely prevented SD occurrence during the infusions (n = 8), implicating microembolization from carotid thrombi as the trigger. Sham-operated mice never developed SD. Systemic infusion of ET-1 did not affect the electrical SD threshold or KCl-induced SD frequency. Conclusion Intravascular ET-1 does not trigger or increase susceptibility to SD. Microembolization was the likely trigger for migraine auras in patients during carotid puncture.

In Vitro Comparison of Four Cerebral Protection Filters for Preventing Human Plaque Embolization during Carotid Interventions

2002 ◽  
Vol 9 (6) ◽  
pp. 793-802 ◽  
Author(s):  
Stefan Müller-Hülsbeck ◽  
Thomas Jahnke ◽  
Carsten Liess ◽  
Christoph Glass ◽  
Friedrich Paulsen ◽  
...  
Keyword(s):  
Carotid Artery ◽  
Carotid Bifurcation ◽  
External Carotid Artery ◽  
Cerebral Protection ◽  
External Carotid ◽  
Carotid Angioplasty ◽  
Protection Device ◽  
Fluid Medium ◽  
Vitro Model

Purpose: To evaluate in an in vitro bench-top model the efficacy of 4 filtration devices designed for cerebral protection during carotid angioplasty. Methods: Embolization during carotid angioplasty was simulated with human plaque material (8 to 12 particles weighing 6.02 ± 0.10 mg) in an open flow model with the aortic arch and carotid bifurcation made from elastic silicone tubes and saline used as the fluid medium. The 500 to 1500-µm particles were injected into the internal carotid artery (ICA) in front of the test protection device, which was deployed 5 cm distal to the bifurcation. Particles getting past the protection device or flowing into the external carotid artery (ECA) were caught in 100-µm filters and weighed. Ten trials were made on each of 4 devices: Angioguard, FilterWire EX, TRAP, and NeuroShield. All were deployed according to the manufacturers' directions except the FilterWire, which was manually repositioned in all tests to eliminate a gap between the filter and the tube wall. Results: The lowest weight of missed particles in the effluent was obtained with the NeuroShield (0.05 ± 0.04 mg, 0.8% of injected particle weight) and FilterWire (0.08 ± 0.05 mg, 1.3%; p=0.254 compared to NeuroShield, p=0.006 versus TRAP). The weight of particles missed by the TRAP device (0.16 ± 0.06 mg, 2.6%; p<0.001 versus NeuroShield and Angioguard, p<0.05 compared to Filter Wire) was higher, and the largest amount of missed particles was observed with the Angioguard filter (0.27 ± 0.06 mg, 4.4%; p<0.001 compared to all). NeuroShield and FilterWire were significantly different (p<0.001) compared to Angioguard and TRAP in a pairwise analysis. No embolization into the ECA occurred. Conclusions: In vitro, none of the tested devices had the ability to completely prevent embolization into the ICA. Comparing current designs, the NeuroShield filter and the FilterWire EX captured the highest percentage of human particles in this in vitro model, probably due to their larger filter volume.

Mixing in the Human Carotid Artery during Carotid Drug Infusion Studied with PET

1989 ◽  
Vol 9 (5) ◽  
pp. 681-689 ◽  
Author(s):  
Larry Junck ◽  
Robert A. Koeppe ◽  
Harry S. Greenberg
Keyword(s):  
Carotid Artery ◽  
Carotid Bifurcation ◽  
Drug Infusion ◽  
Arterial Infusion ◽  
Positron Emission ◽  
Volume Of Interest ◽  
Wide Range ◽  
Vinyl Tube ◽  
Catheter Tip ◽  
Human Carotid

The safety and efficacy of drug infusion into the carotid artery require adequate mixing of the infused solution with carotid blood. Using positron emission tomography (PET), we studied the mixing of solutions infused into the human carotid artery in seven patients by analyzing the distribution of [15O]H2O infused into the carotid artery and by vein. At four infusion rates ranging from 0.5 to 10 ml/min, the variability in distribution averaged 16.5–17.8% among the pixels in a large volume of interest, without dependence on the infusion rate. The overall correlation between [15O]H2O influx with arterial infusion and [15O]H2O influx with venous injection was 0.78–0.82 at the four infusion rates, with no trend toward higher correlations at the faster infusion rates. The distribution into the anterior, middle, and posterior cerebral artery territories differed from distribution throughout the entire carotid territory by an average of 6.2–9.6% at the four infusion rates, with no trend toward smaller differences at the faster infusion rates. Infusions performed into a vinyl tube simulating the carotid artery indicated that at 0.5 ml/min, the velocity of fluid exiting the catheter makes no apparent contribution to mixing. We conclude that with infusions at the carotid bifurcation, mixing in the human carotid artery is complete or nearly complete over a wide range of infusion rates. The mixing appears to result from the patterns of blood flow within the artery, and not from jet effects at the catheter tip.

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

Cervical paragangliomas: diagnosis, management and complications

2001 ◽  
Vol 115 (6) ◽  
pp. 467-474 ◽  
Author(s):  
M. Hossam Thabet ◽  
Hesham Kotob
Keyword(s):  
Carotid Artery ◽  
Superior Laryngeal Nerve ◽  
Carotid Bifurcation ◽  
Styloid Process ◽  
External Carotid Artery ◽  
External Carotid ◽  
Digastric Muscle ◽  
Vascular Injuries ◽  
Nerve Paralysis ◽  
Transcervical Approach

Sixteen patients were diagnosed as suffering from cervical paragangliomas. Eleven patients (68.75 per cent) had twelve carotid paragangliomas (CPs), and five patients (31.25 per cent) had six vagal paragangliomas (VP). One CP (8.33 per cent) originated from paraganglia around the common carotid artery (CCA). Three cases of multiple paragangliomas are presented (18.75 per cent). In 80 per cent (4/5) of VP patients there was widening of the carotid bifurcation similar to that seen with CP. This widening occurred whenever the VP was large enough to grown in between the external carotid artery and internal carotid artery (ECA and ICA). Large VPs may displace the vessels either anterolaterally or anteromedially. Knowledge of the direction of the carotid displacement is essential to avoid intra-operative vascular injuries. Colour flow doppler ultrasound (CFD-US) was found to be a good non-invasive method for diagnosis of vascular neck swellings. It enabled the diagnosis of CP with 100 per cent accuracy, but it was not sufficient for diagnosis of high VP. A transcervical approach, cutting the digastric muscle and the styloid process with the attached ligaments and muscles, was sufficient for excision of most VP. However, midline mandibulotomy might be necessary with high VP. Vascular injuries occurred in 12.5 per cent (2/16) of patients. Superior laryngeal nerve and hypoglossal nerve paralysis occurred, respectively, in (2/11) and (1/11) of patients with CP. Vagal paralysis occurred in all patients with VP. Cerebrovascular accident and post-operative death occurred in one patient (6.26 per cent).

scholarly journals Variations, relations and clinical significance of carotid arterial system in anterior neck: a cadaveric study

2019 ◽  
Vol 7 (4) ◽  
pp. 1127
Author(s):  
Anasuya Ghosh ◽  
Subhramoy Chaudhury ◽  
Atin Datta
Keyword(s):  
Carotid Artery ◽  
Carotid Arteries ◽  
Internal Carotid ◽  
Hypoglossal Nerve ◽  
Carotid Bifurcation ◽  
External Carotid Artery ◽  
Arterial System ◽  
External Carotid ◽  
The Common ◽  
Carotid Arterial

Background: The common carotid, internal and external carotid arteries and their branches serve as major source of blood supply in head-neck region of human and are often encountered during numerous surgical and clinical interventions of neck.Methods: We dissected and examined both sides of neck in 49 well embalmed cadavers (98 sides). We recorded the following anatomical parameters of carotid arterial system-level of bifurcation, the relation between internal and external carotid arteries, branching pattern of anterior branches of external carotid artery, tortuosity in carotid arterial system, and relation of hypoglossal nerve with the carotid arteries.Results: In 56.16 % cases, the common carotid arterial bifurcation took place at the upper border of thyroid cartilage though high bifurcation was quite common (43.88%). The external carotid artery was located antero-medial to internal carotid artery in most cases (93.87%). Abnormal tortuosity of carotid arterial system was detected in 2.04% cases only. In 86.73% cases, the hypoglossal nerve crossed the internal and external carotid artery superior to carotid bifurcation above the level of hyoid bone while in 1 case it crossed immediately inferior to carotid bifurcation. In branching pattern, following variations were observed- linguo-facial trunk in 15.3% cases, thyro-lingual trunk in 5.1% cases, origin of superior thyroid artery from common carotid in 10.02% cases and origin of superior thyroid from internal carotid in one case (1.02%).Conclusions: The carotid arterial system has complex and variable anatomy in neck and this information should be kept in mind to avoid unwanted damage during surgical procedures of neck.

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