Analysis of Computational Fluid Dynamics and Particle Image Velocimetry Models of Distal-End Side-to-Side and End-to-Side Anastomoses for Coronary Artery Bypass Grafting in a Pulsatile Flow

Abstract

deSTS anastomosis has not yet been reported. This study is designed to investigate flow fields in deSTS-simulated left internal thoracic artery (LITA)-left anterior descending artery (LAD) anastomoses, examine differences between deSTS and ETS anastomoses in flow fields using computational fluid dynamics (CFD), and validate the findings via particle image velocimetry (PIV). MethodsThe internal thoracic artery (ITA) is a proven excellent conduit to use when performing CABG. ETS or deSTS anastomoses are usually used to connect the distal end of the ITA-LAD anastomoses. Therefore, in our model, it was assumed that the anastomoses were to the distal end of the LITA-LAD anastomoses.A series of separate studies were performed. First, steady and pulsatile flows were investigated in an actual size model (Model A) using CFD. Next, CFD simulations and PIV measurements of the steady flow were used to validate C oronary artery bypass grafting (CABG) has long been used to facilitate arterial revascularization. Anastomotic intimal hyperplasia (IH) is a major cause of graft failure. It has been shown that hemodynamic factors are involved in IH formation and progression. 1,2 These factors include disturbed blood flow patterns, low and oscillating wall shear stress (WSS), sufficiently high WSS, large spatial WSS gradients, and the stagnation of blood cells. 3, 4 Grafts to the coronary artery commonly involve end-toside (ETS) anastomoses. It has been shown that, after such procedures, IH develops predominantly at the toe and heel of such anastomoses and on the arterial floor across the junction, where the disturbance of flow patterns and other hemodynamic factors have reportedly been observed. 2, 5 Meanwhile, several recent studies have reported the usefulness of distal-end side-to-side (deSTS) anastomoses. 6,7 Umezu et al 8 reported that deSTS anastomoses lose less energy than ETS anastomoses. However, a detailed 3-dimensional assessment of the hemodynamic characteristics of Background: Intimal hyperplasia (IH) is a major cause of graft failure. Hemodynamic factors such as stagnation and disturbed blood flow are involved in IH formation. The aim of this study is to perform a comparative analysis of distal-end side-to-side (deSTS) and endto-side (ETS) anastomoses using computational fluid dynamics (CFD) after validating the results via particle image velocimetry (PIV).

Patient-Specific Hemodynamics of New Coronary Artery Bypass Configurations

“…Furthermore, proposed clinical performance indices are based on mean flow measurements as it is complicated to impose synchronized catheter measurements that pose large clinical error levels. Steady state simulations are therefore promising as many researchers have been used and showed a good agreement with in vivo/vitro data [30,45] and justified particularly for comparative purposes. In addition, current CFD simulation is based on a rigid model which does not account for the compliance of the arteries and the pulsatile rotation movement of the heart as well as induce deformations in the 3D geometries of coronary arteries.…”

Modeling of Hemodynamics in a Vascular Bioprosthesis

“…Важным, с точки зрения послеоперационных осложнений, в имплантации способом «конец-в-бок» являются места соединения обходного русла и основного сосуда, зоны анастомоза [34,43,44,45].…”

“…Граничное условие изменения давления на левой границе (входе) в зависимости от времени взято согласно графику (рис. 3)[14,33,34].…”

Investigating a pulsating flow in the smooth channel and at the bifurcation section with regard to the popliteal artery hemodynamics

“…However, these processes have been studied insufficiently. In addition, there are only few published papers, where the experimental methods were used independently, rather than to validate a numerical code [9][10]. The present paper elaborates on a description of an experimental setup developed by the authors for the study of pulsating flows and ensuring high stability of a given law of flow rate variation, high amplitude of pulsations and reproducing the reverse flow during a fraction of pulsation period.…”