Numerical simulation of blood fluid in hemodialysis catheters and its thrombogenic potential

Abstract

The present study aimed to numerically simulate blood flow within central venous catheters of hemodialysis and its thrombogenic potential. Numerical simulation research performed through the dynamic computational program of fluids. A three-dimensional geometry of right and left internal jugular veins were built, taken from the Visible Human Project®. Catheters with obstructed and unobstructed lateral holes were constructed. For the simulation, we considered the duration of the cardiac cycle of 0.8 s with pulsatile cycle of 75 beats per minute. Shear stress, velocity and pressure increased when the catheter was within the vein and when they were obstructed. At the venous orifice of the catheter that was unobstructed, the velocity increased from 0.99 ± 0.02 m s-1 to 1.79 ± 0.009 m s-1 and the pressure from 1487 ± 0.8 Pa to 3215 ± 0.7 Pa. Blood re-circulation areas have created areas of stagnation of blood flow, making it more susceptible to the development of venous thrombi. This study may contribute to the expansion of multiprofessional partnerships between health professionals and Bioengineering fields in order to study health problems that can be verified through advanced technologies. Such technologies, such as simulation programs, detail possible adverse events based on scientific evidences which often occur silently in patients.

Hemostatic changes in patients undergoing hemodialysis: Differences between central venous catheters and arterio‐venous fistulas

“…This result was also demonstrated in other studies that investigated thrombus formation in CVC for hemodialysis and variations in shear stresses in the vessel wall. 6 CVC can cause high shear stresses in the vein wall and stimulate thrombus formation.…”

“…5 Although CVC is not the gold standard, mainly due to infections and thrombotic complications, its permanent insertion is still a reality in patients in which the fistula may present difficulty in maturation, such as in cases of diabetes, hypertension, coagulopathies, neurological and immunological pathologies, or due to thromboembolic adverse events in AVF. 6 Regarding the use of AVF, one of the main problems is the high frequency of primary failures, due to lack of maturation or early thrombosis, in addition, other complications may also arise, such as aneurysms, infections and venous hypertension. 7 The development of thrombi is common to both CVC and AVF and activates both the blood clotting process and the expression of platelet markers on platelet surfaces.…”

“…7 The development of thrombi is common to both CVC and AVF and activates both the blood clotting process and the expression of platelet markers on platelet surfaces. 6 When the coagulation system is activated, platelet activation and the expression of glycoprotein complexes such as the integrin GPIIb/IIIa (CD41a) or p-selectin (CD62P), which aim to regulate the coagulation reactions that lead to the generation of thrombin. 7 The GPIIb/IIIa integrin is a membrane protein complex essential for platelet aggregation and is the most abundant glycoprotein on platelet surfaces.…”

Dialysis flow rate in central venous catheters – A numerical analisys with experimental validation.

“…Mathematical models, based on Eulerian and Lagrangian formulations, have been commonly used to estimate the platelet lysis index (PLI) of the blood [22]. For the implementation of Lagrangian models, it is necessary to inject particles in the simulation domain, and the solutions depends on the way in which the integration along the trajectory lines are made.…”

“…For the implementation of Lagrangian models, it is necessary to inject particles in the simulation domain, and the solutions depends on the way in which the integration along the trajectory lines are made. Moreover, it is also difficult to ensure that particles will pass through the interest regions of the domain [22,23]. The Eulerian model, on the other hand, is based on partial differential equations, which means that, when integrated into the control volume provide the quantities throughout the entire calculation domain [23].…”