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.

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.

Three Dimensional Numerical Analysis of Flow Through the Human Carotid Bifurcation With Varying Degrees of Stenotic Plaque Formation

2007 ◽  
Author(s):  
Scott T. Lovald ◽  
Tariq Khraishi ◽  
Juan C. Heinrich ◽  
Howard Yonas ◽  
Christopher L. Taylor
Keyword(s):  
Numerical Analysis ◽  
Carotid Artery ◽  
Three Dimensional ◽  
Carotid Bifurcation ◽  
Local Flow ◽  
Flow Through ◽  
High Degree ◽  
The Brain ◽  
Insight Into ◽  
Human Carotid

The human carotid artery bifurcation is often affected by plaque and atherosclerotic formations. A high degree of stenosis due to plaque deposit in the carotid artery can significantly diminish blood flow to the brain [1]. For three decades, local flow anomalies such as flow separation, recirculation, low wall shear stress, and high local particle residence time are factors that have been implicated in the development of arterial diseases [3, 1]. Numerical analysis of flow through a stenotic carotid bifurcation provides insight into local flow dynamics and an assessment of the risks of particular modes and degrees of stenosis.

scholarly journals Postmortem Pathological Examination of a Case One Month after Carotid Artery Stenting

2000 ◽  
Vol 6 (1_suppl) ◽  
pp. 171-174
Author(s):  
Y. Otsuka ◽  
R. Waki ◽  
C. Yutani ◽  
H. Ishibashi-Ueda ◽  
T. Onodera ◽  
...  
Keyword(s):  
Carotid Artery ◽  
Carotid Artery Stenting ◽  
Carotid Bifurcation ◽  
Carotid Stenting ◽  
Pathological Process ◽  
Coronary Stenting ◽  
Pathological Examination ◽  
Eccentric Compression ◽  
Human Carotid

There have been few pathological reports on human carotid stenting. A 73-year-old diabetic male with 80% stenosis in the left carotid bifurcation. Despite no neurological events, he died of pneumonia one month after. Findings pathological examination revealed: successful dilatation without deformity of the stent, eccentric compression and partial disruption of the plaque by struts, thrombi around disrupted plaque, and neointimal growth. Findings were generally compatible with those reported on coronary stenting. Case accumulation is required to clarify an exact pathological process and establish a procedure to reduce complications.

A carotid bifurcation pseudoaneurysm treated endovascularly in a patient with irradiated neck

VASA ◽  
2019 ◽  
Vol 48 (2) ◽  
pp. 193-195
Author(s):  
Christiana Anastasiadou ◽  
Chrisostomos Maltezos ◽  
George Galyfos ◽  
Sotirios Giannakakis ◽  
Nikos Zannes ◽  
...  
Keyword(s):  
Carotid Artery ◽  
Endovascular Treatment ◽  
Carotid Bifurcation ◽  
Rare Entity ◽  
Artery Pseudoaneurysm

Abstract. A carotid artery pseudoaneurysm in an irradiated neck is a rare entity with possible devastating results and management should be multidisciplinary. We present a successful endovascular treatment of a late carotid artery pseudoaneurysm following patch endarterectomy and cervical radiotherapy.

scholarly journals Synchronous Carotid Bifurcation Endarterectomy and Retrograde Kissing Stenting of the Innominate and Left Common Carotid Artery in a Patient with a Bovine Aortic Arch

2017 ◽  
Vol 2017 ◽  
pp. 1-4 ◽  
Author(s):  
Alessandro Robaldo ◽  
Guido Carignano ◽  
Alberto Balderi ◽  
Claudio Novali
Keyword(s):  
Carotid Artery ◽  
Aortic Arch ◽  
Common Carotid Artery ◽  
Carotid Arteries ◽  
High Risk Patient ◽  
Carotid Bifurcation ◽  
Left Common Carotid Artery ◽  
The Right ◽  
Bovine Aortic Arch ◽  
Common Carotid Arteries

Management of the symptomatic multiple stenosis of supra-aortic vessels (MSSVs) in a “bovine” aortic arch (BAA) configuration is infrequently reported. The optimal treatment choice remains debatable. A successful hybrid treatment for a proximal critical stenosis of the innominate and left common carotid artery was performed in a high-risk patient with a tandem symptomatic lesion in the right carotid bifurcation and a concentric vulnerable plaque in the bovine trunk. This case supports the feasibility, safety, and efficacy of a combined carotid bifurcation endarterectomy and retrograde kissing stenting of common carotid arteries with cerebral protection after evaluation of radiological, anatomical, and clinical parameters.

Reversal of Focal Misery Perfusion after Intracranial Angioplasty: Case Report

Neurosurgery ◽  
2001 ◽  
Vol 48 (2) ◽  
pp. 436-440 ◽  
Author(s):  
Colin P. Derdeyn ◽  
DeWitte T. Cross ◽  
Christopher J. Moran ◽  
Ralph G. Dacey
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Carotid Artery ◽  
Intracranial Stenosis ◽  
Oxygen Extraction Fraction ◽  
Oxygen Extraction ◽  
Positron Emission ◽  
Misery Perfusion ◽  
Before And After ◽  
Hemodynamic Measurements

Abstract OBJECTIVE AND IMPORTANCE The presence of reduced blood flow and increased oxygen extraction fraction (OEF) (misery perfusion) in the hemisphere distal to an occluded carotid artery is a proven risk factor for subsequent stroke. Whether angioplasty of intracranial stenosis is sufficient to reverse this condition has not been documented. CLINICAL PRESENTATION A 67-year-old man exhibited progressive right hemispheric ischemic symptoms despite maximal antiplatelet and antithrombotic therapy. Angiography demonstrated focal 80% stenosis of the supraclinoid segment of the ipsilateral internal carotid artery. TECHNIQUE 15O positron emission tomographic measurements of cerebral blood flow and OEF were made before and after transfemoral percutaneous angioplasty. OEF values measured before angioplasty were elevated in the middle cerebral artery distal to the stenosis. Angioplasty reduced the degree of luminal stenosis to 40% (linear diameter). OEF values measured 36 hours after angioplasty were normal. CONCLUSION Angioplasty of intracranial stenosis can restore normal cerebral blood flow and oxygen extraction, despite mild residual stenosis after the procedure. Hemodynamic measurements may be useful for the identification of patients with the greatest potential to benefit from angioplasty.

scholarly journals Effects of lowered serotonin transmission on cocaine-induced striatal dopamine response: PET [11C]raclopride study in humans

2011 ◽  
Vol 199 (5) ◽  
pp. 391-397 ◽  
Author(s):  
Sylvia M. L. Cox ◽  
Chawki Benkelfat ◽  
Alain Dagher ◽  
J. Scott Delaney ◽  
France Durand ◽  
...  
Keyword(s):  
Substance Use ◽  
Substance Use Disorders ◽  
Striatal Dopamine ◽  
Emission Tomography ◽  
Acute Tryptophan Depletion ◽  
Tryptophan Depletion ◽  
Comorbid Conditions ◽  
Drug Craving ◽  
Positron Emission ◽  
Wide Range

BackgroundLow serotonin transmission is thought to increase susceptibility to a wide range of substance use disorders and impulsive traits.AimsTo investigate the effects of lowered serotonin on cocaine-induced (1.0 mg/kg cocaine, self-administered intranasally) dopamine responses and drug craving.MethodIn non-dependent cocaine users, serotonin transmission was reduced using the acute tryptophan depletion method. Striatal dopamine responses were measured using positron emission tomography with [11C]raclopride.ResultsAcute tryptophan depletion increased drug craving and striatal dopamine responses to cocaine. These acute tryptophan depletion-induced increases did not occur in the absence of cocaine.ConclusionsThe results suggest that low serotonin transmission can increase dopaminergic and appetitive responses to cocaine. These findings might identify a mechanism by which individuals with low serotonin are at elevated risk for both substance use disorders and comorbid conditions.

Retrograde Suction Decompression for Clipping of a Giant Ophthalmic Internal Carotid Artery Aneurysm: 2-Dimensional Operative Video

2021 ◽  
Author(s):  
Visish M Srinivasan ◽  
Michael Zhang ◽  
Lea Scherschinski ◽  
Alexander C Whiting ◽  
Mohamed A Labib ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Carotid Artery ◽  
Internal Carotid ◽  
Artery Aneurysm ◽  
Carotid Bifurcation ◽  
Aneurysm Neck ◽  
Microsurgical Clipping ◽  
Complex Anatomy ◽  
Internal Carotid Artery Aneurysm ◽  
Paraclinoid Aneurysms

Abstract Microsurgical clipping of large paraclinoid aneurysms is challenging because of the complex anatomy of the dural rings, lack of easy proximal control, and wide aneurysm necks. Proximal retrograde suction decompression, or the Dallas technique, can reduce aneurysm turgor and, with aspiration of the trapped cervical and supraclinoid internal carotid arteries (ICAs), can collapse the aneurysm to aid microsurgical clipping.1-5  A woman in her late 30s presented with decreased right-eye visual acuity. Informed written consent was obtained for microsurgical management and publication. Upon cervical exposure of the carotid bifurcation, we performed a standard pterional craniotomy, trans-sylvian exposure, and intradural anterior clinoidectomy. After burst suppression and cross-clamping of the carotid, we inserted an angiocatheter at the common carotid artery (CCA). Distal temporary clips were placed on the posterior communicating artery and C7 ICA. With the cervical ICA unclamped, retrograde suction was continuously applied to deflate the aneurysm. We applied 2 pairs of fenestrated-booster clips to the aneurysm dome and a fifth clip to the aneurysm neck. After restoration of flow, indocyanine green angiography and Doppler assessments were performed. The proximal clip was converted into a curved clip to optimize ICA flow.  Postoperative angiography confirmed complete occlusion of the aneurysm. The patient was discharged on postoperative day 3, with stable visual acuity.6 This video demonstrates that retrograde suction decompression via the cervical CCA can be safely performed to facilitate clipping of complex paraclinoid ICA aneurysms. Comprehensive planning of temporary aneurysm trapping for suction decompression and permanent clip construct for aneurysm occlusion are needed for effective aneurysm repair.

Prostaglandin Endoperoxide Metabolism by the Human Carotid Artery

1985 ◽  
pp. 333-341
Author(s):  
D. B. McNamara ◽  
D. S. Rush ◽  
M. D. Kerstein ◽  
J. A. Bellan ◽  
P. R. Mayeux ◽  
...  
Keyword(s):  
Carotid Artery ◽  
Prostaglandin Endoperoxide ◽  
Human Carotid
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