Numerical modelling of the interaction between dialysis catheter, vascular vessel and blood considering elastic
Zihan Chen1,2, Qijun Zheng1,2, Zhenbo Tong1,3
1Southeast University-Monash University Joint Research Institute, Suzhou, China.
Insights
Central venous catheters (CVCs) can cause thrombus and stenosis due to altered blood flow. This study simulated CVC implantation, revealing spiral flow and high wall shear stress (WSS) near the catheter tip, increasing complication risks.
Area of Science:
- Biomedical Engineering
- Fluid Dynamics
- Medical Device Design
Background:
- Dialysis catheters (CVCs) indwelling in patients pose a significant risk for thrombus and stenosis formation.
- Biomechanical research indicates that vascular wall shear stress (WSS) is a key factor triggering these physiological complications.
Purpose of the Study:
- To assess the hemodynamic impact of CVC implantation on central veins.
- To identify alterations in the hemodynamic environment linked to thrombus development after CVC placement.
Main Methods:
- Computational Fluid Dynamics (CFD) and Finite Element Analysis (FEA) were employed to simulate blood flow and vascular mechanics.
- A patient-specific Superior Vena Cava (SVC) model was created from CT images.
- Fluid-Structure Interaction (FSI) simulations considered the elastic interaction between the vessel wall and blood flow, including catheter vibration.
Main Results:
- CVC indwelling induced spiral and recirculation blood flow patterns near the catheter tip.
- High Oscillatory Shear Index (OSI) and WSS regions were identified at the catheter tip and vascular junction.
- Catheter vibration, with amplitudes up to 10% of vessel width, was observed due to blood pressure variations.
Conclusions:
- CVC implantation significantly alters central venous hemodynamics, creating conditions conducive to thrombus formation.
- The catheter tip and its interaction with the vessel wall are critical areas for elevated WSS and OSI.
- FSI simulation highlights the importance of considering vessel wall deformability and catheter movement in predicting complications.
Abstract:
The dialysis catheter indwelling in human bodies has a high risk of inducing thrombus and stenosis. Biomechanical research showed that such physiological complications are triggered by the wall shear stress of the vascular vessel. This study aimed to assess the impact of CVC implantation on central venous haemodynamics and the potential alterations in the haemodynamic environment related to thrombus development. The SVC structure was built from the images from computed tomography. The blood flow was calculated using the Carreau model, and the fluid domain was determined by CFD. The vascular wall and the CVC were computed using FEA. The elastic interaction between the vessel wall and the flow field was considered using FSI simulation. With consideration of the effect of coupling, it was shown that the catheter vibrated in the vascular systems due to the periodic variation of blood pressure, with an amplitude of up to 10% of the vessel width. Spiral flow was observed along the catheter after CVC indwelling, and recirculation flow appeared near the catheter tip. High OSI and WSS regions occurred at the catheter tip and the vascular junction. The arterial lumen tip had a larger effect on the WSS and OSI values on the vascular wall. Considering FSI simulation, the movement of the catheter inside the blood flow was simulated in the deformable vessel. After CVC indwelling, spiral flow and recirculation flow were observed near the regions with high WSS and OSI values.
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