Artery In Presence Research Articles

Modeling of nanoblood flow in an artery in presence of eco-friendly and biocompatible hybrid nanoparticles

Transferring biological fluid through arteries is a topic that has garnered serious interest in recent times, especially when it pertains to applications such as drug delivery. In our body, arteries serve as the primary conduits for blood flow and this study aims to model the blood flow in this situation. The working fluid is essentially pure blood, which acts as a base fluid, supplemented with nanoparticles of Titanium Dioxide (TiO2) and Gold (Au). Nanoparticles could change the thermal and rheological properties of blood which might be particularly advantageous for ensuring smoother flow or optimal distribution of drug molecules within the bloodstream. In the present work, a porous channel is considered with parallel walls that exhibit varying permeability on boundaries. Such a design enables the nanoblood to enter and exit the channel, mimicking certain natural processes like transvascular fluid exchange. Additionally, the variable height of the channel that expands and squeezes uniformly could be reminiscent of the pulsatile nature of blood flow seen in our arteries due to heartbeats. To understand the dynamics of this hybrid nanoblood flow, the governing equations are converted into a set of nonlinear ordinary differential equations using the similarity transformation approach. For solving these transformed equations, the research harnesses the BVP4C built-in function in MATLAB software. Through this computational approach, the research provides insights into the velocity and temperature profile of the fluid, the distribution of normal pressure, wall shear stress, and the Nusselt number concerning various parameters. The findings of the present study can be significant and useful in biological sciences and technologies and the detailed results are presented completely in the article’s body.

Evaluation of Diameter of Main Hilar Renal Artery to Predict the Presence of Supplementary Renal Artery by Contrast-enhanced MDCT: A Retrospective Study from in Northern India

Introduction: Accessory renal arteries are non anastomotic end arteries that correspond to a single renal artery’s segmental branch. It is the most common anatomic variation of renal artery, with an incidence ranging from 8.7% to 75.7%. Aim: To determine the normal reference range of diameter of the main hilar renal artery in presence or absence of supplementary renal arteries and using contrast-enhanced Multidetector Computerized Tomography (MDCT) in North Indian population. Materials and Methods: This retrospective study was conducted in the Department of Anatomy in collaboration with the Department of Radiodiagnosis at Santosh Medical College and Hospital, Ghaziabad and Dr. O.P Gupta Imaging Centre, Meerut, Uttar Pradesh, India, from April 2019 to October 2021. Data analysis was done from November 2021 to December 2021. Contrast-enhanced MDCT scan images were reviewed for measurement of the diameter of main hilar and supplementary renal artery. A total of 108 patients were recruited through consecutive sampling. The diameter of the main hilar and supplementary renal artery on each side was measured at the site of origin from the abdominal aorta with the help of an electronic calliper in axial view of MDCT images. The mean differences among the groups with and without supplementary renal artery were evaluated using the student’s t-test. Results: The mean diameter of the main hilar renal artery in the absence of the supplementary renal arteries on the right and left side were 5.99±1.13 mm and 6.07±1.25 mm respectively.The mean diameter of the main hilar renal artery with supplementary renal arteries on the right side was 5.11±1.096 mm and on the left was 5.18±1.08. The mean diameter of the main hilar renal artery was smaller in kidneys with a supplementary renal artery than in those without a supplementary renal artery, statistically significant difference was evaluated (p-value<0.001 on the right and left side). Conclusion: The diameter of the main hilar renal artery can indicate whether supplemental renal arteries exist or not.

Mathematical Analysis of an Atherosclerotic Artery in Presence of Externally Applied Magnetic Field

In general Atherosclerosis is the narrowing of the arteries caused by formation of plaque (fat and calcium) in inner arterial wall. Hardening in inner wall of the arteries restricts the speed of flow in the arteries, which prevents the organs and tissues to get sufficient oxygenated blood for smooth functioning. The characteristics of blood and its flow can deliberate the fundamental understanding with respect to different rheological and haemodynamic properties of blood, which may help in detection and medication of several cardio-vascular, cerebro-vascular and arterial diseases. Many cardio-vascular diseases are caused due to abnormal flow of blood caused by stenosis (tapered segment in local lumen of the inner arterial wall). The arterial turbulence and flow variations are mainly caused by means of unpleasant arterial flow of blood and viscous head losses due to stenosis. The platelets of blood are generally activated by means of very high shear-stresses near stenosis-throat. The induced thrombosis may cause reduced flow velocity of blood flow to the brain and heart. The collective applications of analytical measures and numerical techniques may analyze the problem for more quantifiable investigation. It has been notified to different analytical study that the resistance of flow causes the increase of inner wall skin-friction with simultaneous increase of height of stenosis. Here the character of flow in artery is considered as axi-symmetric in nature. The measure of asymmetrical stenosis found from a mild stenosed artery in threedimensional structure, so that from physiological approach analysis would be more authentic under consideration with the different parameters of flow. According to the rheological parameters the flow model is considered to be Herschel-Bulkley fluid Model. The outcomes connected to Newtonian model of flow are represented as a distinct event of investigations by assuming the suitable values of fluid-index considered as “n”. Blood is characterized as a fluid having electrical conductance, the externally applied magneto hydrodynamic effects are also applied to reduce the flow acceleration of blood in arteries. The analysis is much efficient to explore the collective measures of data information related to phenomena of physiological problem in Atherosclerotic artery.

A surrogate model for plaque modeling in carotids based on Robin conditions calibrated by cine MRI data.

We propose a surrogate model for the fluid-structure interaction (FSI) problem for the study of blood dynamics in carotid arteries in presence of plaque. This is based on the integration of a numerical model with subject-specific data and clinical imaging. We propose to model the plaque as part of the tissues surrounding the vessel wall through the application of an elastic support boundary condition. In order to characterize the plaque and other surrounding tissues, such as the close-by jugular vein, the elastic parameters of the boundary condition were spatially differentiated and their values were estimated by minimizing the discrepancies between computed vessel displacements and reference values obtained from CINE Magnetic Resonance Imaging data. We applied the model to three subjects with a degree of stenosis greater than 70%. We found that accounting for both plaque and jugular vein in the estimation of the elastic parameters increases the accuracy. In particular, in all patients, mismatches between computed and in vivo measured wall displacements were one to two orders of magnitude lower than the spatial resolution of the original MRI data. These results confirmed the validity of the proposed surrogate plaque model. We also compared fluid-dynamics results with those obtained in a fixed wall setting and in a full FSI model, used as gold standard, highlighting the better accordance of our results in comparison to the rigid ones.

Comparative study of rotational atherectomy and endarterectomy in the treatment of atheromatous lesions of the common femoral artery in presence of a high hemorrhagic risk

Endarterectomy with or without patch angioplasty is regarded as the treatment of reference of the stenoses of the common femoral artery (CFA). However, the use of active stents in the treatment of acute coronary syndromes (ACS) increases and requires the continuation of a double antiplatelet aggregation (APA) during a minimum of three months. Endovascular techniques as an alternative to conventional surgery might be less invasive to treat these severe lesions of the CFA. We analyzed the results of atherectomy in these patients at high hemorrhagic risk compared to endarterectomy to treat CFA lesions in patients admitted for a critical lower limb ischemia.

Blood flow through arteries in presence of transverse magnetics field

The aim of the study of this paper is the application of magneto hydrodynamics in physiological problems to develop a mathematical model for the study of blood flow in the presence of magnetic effect through stenosis arterial segment. Herschel-Bulkley equation has been taken to the non-Newtonian character of blood flow in the presence of applied magnetics effect. The mathematical model is analyzed through graphically and numerically. As blood is an electrically conducting the magneto hydrodynamic principle may be used to decelerate the flowing blood in a human arterial system and treatment of certain cardiovascular disease.

The role of intraoperative angiography in the treatment of an acute impassability of the lower extremity artery

Objective. To compare the results of surgical treatment of patients, suffering an acute impassability of the lower extremity arteries (LEA) , using and not using intraoperative angiography.
 Materials and methods. Comparative analysis of the surgical treament results was done in the Centre of Vascular Surgery of Clinical Hospital “Feofania”, where in 2010-2017 yrs 119 patients, suffering an acute impassability of the LEA, were treated. All 119 patients investigated were divided into two groups: the Group I - 70 (58.8%) patients, in whom open thrombectomy, using Fogarty catheter, was performed to correct an acute ischemia of the lower extremity, and the Group II - 49 (41.2%) patients, in whom open thrombectomy, using Fogarty catheter, was followed by the control intraoperative angiography. Taking into account the results of angiography after thrombectomy, the balloon angioplasty was conducted, open surgical interventions on the arteries or thrombectomy only.
 Results. Performance of intraoperative angiography after thrombectomy gives possibility to determine the origin of an acute impassability of the arteries precisely, to accomplish intraoperative roentgenological control of the thrombectomy conduction and to estimate its quality, to establish a substantiated indications for endovascular and open surgical interventions on the arteries in presence of their stenotic-occlusive affections on background of atherosclerotic process. Expediency of application of intraoperative angiography was witnessed by trustworthily higher rate of thrombectomy performance with positive immediate result in the patients of Group II (97.9%), comparing with the patients of Group I (88.6%) (p < 0.05), as well as the recurrence rate for an acute arterial impassability during a year, which was trustworthily higher in the Group I patients, comparing with the Group II patients – 30.7 and 8.2% (p < 0.001), accordingly.
 Conclusion. Application of intraoperative angiography and performance of interventions on the arteries in accordance to indications while doing thrombectomy for an acute impassability of the LEA gives possibility to enhance the rate of immediate positive results of the operation and to lower the recurrence rate for an acute arterial impassability during a year trustworthily.

Flow of a Herschel-Bulkley Fluid in a Channel with Elastic Walls

In order to model the blood flow through an artery in presence of catheter, we considered a steady, laminar, incompressible, Poiseuille flow of a Herschel-Bulkley fluid between two horizontal parallel elastic walls. The power law index ( ) and yield stress ( ) are the two parameters of the Herschel - Bulkley fluid. By giving different values for the above mentioned parameters, we get the Newtonian, Bingham and Power-law fluids as special cases. The exact solutions for the flow quantities such as velocity, plug flow velocity and flux are derived. The flux is determined as a function of inlet, outlet, external pressures and the elastic property of the channel. The effect of elastic parameters on flux variation is analyzed. Further when and our results qualitatively agree with those of Rubinow and Keller [2]. In addition, velocity of the Herschel- Bulkley fluid flow is expressed in terms of elastic parameters.

Study on blood flow containing nanoparticles through porous arteries in presence of magnetic field using analytical methods

In this paper, flow analysis for a third grade non-Newtonian blood in porous arteries in presence of magnetic field is simulated analytically and numerically. Blood is considered as the third grade non-Newtonian fluid containing nanoparticles. Collocation Method (CM) and Optimal Homotopy Asymptotic Method (OHAM) are used to solve the Partial Differential Equation (PDE) governing equation which a good agreement between them was observed in the results. The influences of the some physical parameters such as Brownian motion parameter, pressure gradient and thermophoresis parameter, etc. on temperature, velocity and nanoparticles concentration profiles are considered. For instance, increasing the thermophoresis parameter (Nt) caused an increase in temperature values in whole domain and an increase in nanoparticles concentration near the inner wall.

Mathematical modelling of couple stresses on fluid flow in constricted tapered artery in presence of slip velocity-effects of catheter

This paper explores the mathematical model for couple stress fluid flow through an annular region. The above model is used for studying the blood flow between the clogged (stenotic) artery and the catheter. The asymmetric nature of the stenosis is considered. The closed form expressions for the physiological parameters such as impedance and shear stress at the wall are obtained. The effects of various geometric parameters and the parameters arising out of the fluid considered are discussed by considering the slip velocity and tapering angle. The study of the above model is very significant as it has direct applications in the treatment of cardiovascular diseases.

P08.16: Systematic thickness analysis of the adipose tissue around the fetal arm across gestation using 2D ultrasound images

year. Results: Three cases of intrauterine growth restriction (IUGR) at 35 and 29 weeks presented an aorta abdominal intima thickening and a condensation of the elastic fibers forming an evident internal elastic membrane with the presence of inflammatory elements, such as macrophages and activated endothelial cells. Two monochorionic twin pregnancies hesitated with the death of triplets at 25 weeks (IUGR and twin-to-twin transfusion syndrome); they presented an aortic hemorrhagic peri-adventitial dissociation. In both cases were present fetal Doppler abnormalities, in particular an increase of the systolic velocity of umbilical artery in presence of IUGR and an absent diastolic flow and ductus venosus alterations in twins. A Down fetus at 22 weeks showed a sub occlusive thrombosis of the abdominal aorta with delamination of the aortic wall and the presence of media-intimal foamy macrophages, without Doppler alterations in utero. Finally, a fetus with Potter’s syndrome at 23 weeks showed a partially organized thrombosis of the abdominal aorta and renal arteries with delamination of the wall and the presence of media-intimal foamy macrophages, as in IUGR ones. Conclusions: all the fetal intrauterine diseases described might be associated to a specific histological arterial findings which could represent underlying conditions predisposing of hypertension and vascular damage in adult life.

Numerical study of flow and heat transfer during oscillatory blood flow in diseased arteries in presence of magnetic fields

A problem motivated by the investigation of the heat and mass transfer in the unsteady magnetohydrodynamic (MHD) flow of blood through a vessel is solved numerically when the lumen of the vessel has turned into the porous structure. The time-dependent permeability and the oscillatory suction velocity are considered. The computational results are presented graphically for the velocity, the temperature, and the concentration fields for various values of skin friction coefficients, Nusselt numbers, and Sherwood numbers. The study reveals that the flow is appreciably influenced by the presence of a magnetic field and also by the value of the Grashof number.

MYOCARDIAL DEFORMATION AND COMPLETE LEFT BUNDLE BRANCH BLOCK

Tissue Doppler imaging is evolving as a useful echocardiographic tool for quantitative assessment of left ventricular systolic and diastolic function. Over the last 10 years, myocardial deformation imaging has become possible initially with tissue Doppler , and more recently with myocardial speckle-tracking using 2D echocardiography. Unlike simple tissue velocity measurements, deformation measurements are specific for the region of interest. Strain rate or strain measurements have been used as sensitive indicators for subclinical diseases, and it is the most widely used tool to assess mechanical dyssynchrony. Left bundle branch block is a frequent, etiologically heterogeneous, clinically hostile and diagnostically challenging entity. About 2% of patients underwent cardiac stress testing show stable or intermittent left bundle branch block. Presence of left bundle branch block is associated with a lower and slower diastolic coronary flow velocity especially during hyperemia. Stress echocardiography is the best option for the diagnosis of ischemic heart disease, albeit specificity and sensitivity reduce in patients with left bundle branch block in the territory of left anterior descending artery in presence of initial septum dyskinesia.

Effect of Slip Velocity on Blood Flow through a Catheterized Artery

A mathematical model for pulsatile flow of blood in a catheterized artery in presence of an axisymmetric stenosis with a velocity slip at the constricted wall is proposed. The expressions for the flow characteristics, velocity profiles, the flow resistance, the wall shear stress, the effective viscosity are obtained in the present analysis. The effects of slip velocity on the blood flow characteristics are shown graphically and discussed briefly.

Blockade of chloride channels reveals relaxations of rat small mesenteric arteries to raised potassium.

1. Raised extracellular K(+) relaxes some arteries, and has been proposed as Endothelium-Derived Hyperpolarizing Factor (EDHF). However, relaxation of rat small mesenteric arteries to K(+) is highly variable. We have investigated the mechanism of K(+)-induced dilatation and relaxation of pressurized arteries and arteries mounted for measurement of isometric force. 2. Raising [K(+)](o) from 5.88 - 10.58 mM did not dilate or relax pressurized or isometric arteries. Relaxation to raised [K(+)](o) was revealed in the presence of 5-nitro-2-(3-phenylpropylamino) benzoic acid (NPPB); this effect of NPPB was concentration-dependent (IC(50): 1.16 microM). 3. Relaxations to raised [K(+)](o) in the presence of NPPB, were abolished by 30 microM Ba(2+) or endothelial-denudation. Acetycholine (10 microM) relaxed endothelium-intact arteries in presence of raised [K(+)](o) NPPB and Ba(2+). 4. Relaxations to raised [K(+)](o) were revealed in hyperosmotic superfusate (+60 mM sucrose). These relaxations were abolished by 30 microM Ba(2+). In the presence of raised [K(+)](o), 60 mM sucrose and 30 microM Ba(2+), 10 microM acetycholine still relaxed all arteries. 5. Fifty microM 18 alpha-glycyrrhetinic acid (18 alpha-GA), a gap junction inhibitor, depressed relaxations to both 10 microM acetylcholine and raised [K(+)](o), in the presence of 10 microM NPPB. 6. In summary, blockade of a volume-sensitive Cl(-) conductance in small rat mesenteric arteries, using NPPB or hyperosmotic superfusion, reveals a endothelium-dependent, Ba(2+) sensitive dilatation or relaxation of rat mesenteric arteries to raised [K(+)](o). We conclude that inwardly rectifying potassium channels on the endothelium underlie relaxations to raised [K(+)](o) in rat small mesenteric arteries.

Profile of coronary arterial disease in diabetic patients undergoing coronary arterial bypass grafting

Diabetics are believed to have more extensive and diffuse lesions of the coronary arteries in presence of coronary arterial disease. We studied prospectively 52 diabetics with coronary arterial disease who underwent coronary arterial bypass grafting and evaluated their pre-operative symptomatology, angiographic appearance of coronary arteries, coronary arterial dimensions as assessed at surgery, and the post-operative complications. These were compared to 52 age and sex matched non-diabetic controls undergoing surgery during the same period. There was no statistically significant difference in the incidence of pre-operative symptomatology or frequency of myocardial infarction in the two groups. Left ventricular angiographic findings were also comparable, as was the observation on the extent and severity of coronary arterial disease as assessed by angiography and at surgery. Hence, we recommend coronary arterial bypass grafting to diabetics with the same criteria as are applied to non-diabetics, confident that there will be no added morbidity and mortality.