Influence of Hemodialysis Catheter Insertion on Hemodynamics in the Central Veins

Abstract

Central venous catheter (CVC) related thrombosis is a major cause of CVC dysfunction in patients under hemodialysis. The aim of our study was to investigate the impact of CVC insertion on hemodynamics in the central veins and to examine the changes in hemodynamic environments that may be related to thrombus formation due to the implantation of CVC. Patient-specific models of the central veins with and without CVC were reconstructed based on computed tomography images. Flow patterns in the veins were numerically simulated to obtain hemodynamic parameters such as time-averaged wall shear stress (TAWSS), oscillating shear index (OSI), relative residence time (RRT), and normalized transverse wall shear stress (transWSS) under pulsatile flow. The non-Newtonian effects of blood flow were also analyzed using the Casson model. The insertion of CVC caused significant changes in the hemodynamic environment in the central veins. A greater disturbance and increase of velocity were observed in the central veins after the insertion of CVC. As a result, TAWSS and transWSS were markedly increased, but most parts of OSI and RRT decreased. Newtonian assumption of blood flow would overestimate the increase in TAWSS after CVC insertion. High wall shear stress (WSS) and flow disturbance, especially the multidirectionality of the flow, induced by the CVC may be a key factor in initiating thrombosis after CVC insertion. Accordingly, approaches to decrease the flow disturbance during CVC insertion may help restrain the occurrence of thrombosis. More case studies with pre-operative and postoperative modeling and clinical follow-up need to be performed to verify these findings. Non-Newtonian blood flow assumption is recommended in computational fluid dynamics (CFD) simulations of veins with CVCs.

Computational investigation of the haemodynamics shows criticalities of central venous lines used for chronic haemodialysis in children

“…Anatomical conditions proved to be useful, also, in evaluating the impact of the CVL insertion on the flow conditions of the SVC. The increase in WSS values, recorded after the insertion of the CVL, may trigger the expression of procoagulant activity or cause vascular endothelial damage, leading to a higher risk of venous thrombosis in agreement with Park ( 15 ). When smaller models (Tesio 6.5 F and Hemo-Cath 8 F) were used, a more disturbed flow, characterized by asymmetric eddies, was observed in the vein cross-section.…”

“…When smaller models (Tesio 6.5 F and Hemo-Cath 8 F) were used, a more disturbed flow, characterized by asymmetric eddies, was observed in the vein cross-section. These flow disturbances could therefore initiate and accelerate thrombosis ( 15 , 16 ).…”

“…The presence of side-holes, placed in proximity of the tip to increase the efficiency of the blood exchange, can also promote blood clot formation and infection, impacting on the longevity of the CVL in vivo ( 11 , 12 ). On the patient side, modelling CVLs function in both simplified working conditions ( 8 , 9 , 11 , 13 ) and replicated anatomical characteristics ( 10 , 14 ) showed the influence of the catheter insertion within the central veins ( 15 , 16 ). Considering the literature consulted, computational studies of CVLs for paediatric use have not been reported in the literature (source: Pubmed) and the reasons for such poor performance are still widely unknown.…”

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

“…Despite of arteriovenous fistulas and arteriovenous grafts have been considered the preferred form of vascular access for hemodialysis, there was an increase in the number of patients using central venous catheter (CVC) [4][5][6][7].…”

Central Venous Catheter Malfunction in Children

“…With smaller CVC models, asymmetric eddies were identified (Figure 1Ac). Similar changes in hemodynamics due to catheter placement increase the risk of venous thrombosis in adult patients on HD (3). When the catheters were used in arterial configuration, blood entered the lumen mainly through the most proximal side holes, regardless of the CVC design and size.…”