Computational modelling of the cephalic arch with jugulocephalic vein variant predicts haemodynamic profiles in patients with brachiocephalic fistula.

Abstract

The cephalic vein is often used in for arteriovenous fistula creation; however, the cephalic vein variation is common. This study will propose new theoretical explanations for a new discovered variation of cephalic vein draining into external jugular vein with "T-junction" shape by means of 3D computational haemodynamic modelling, which may provide reference for clinical practice. The precise measurements were conducted for the variant right cephalic vein draining into external jugular vein and for a normal right cephalic vein as a control. After processing the anatomical data, 3D geometrical model was reconstructed. Then, the influent field inside the variant jugulocephalic vein was mathematically modelled to get a detailed description of haemodynamic environment. The anatomical parameters of the "T-junction" jugulocephalic vein variant were much more different from the normal right cephalic vein. The wall shear stress of variant cephalic vein at the corresponding position was higher and changed more rapidly than that of normal cephalic vein. The shear rate contour lines are disordered in several areas of the variant cephalic vein, indicating that the haemodynamic parameters in these areas are unstable. The haemodynamic characteristics at the confluence of the variant cephalic vein are more complex, with more areas where haemodynamic parameters are disrupted. The variation of cephalic arch in a "T-junction" with external jugular vein largely altered the fluid dynamics, especially in haemodialysis patients with brachiocephalic fistula in terms of the simulating flow in 3D computational model. This computational model provides haemodynamic profiles for stabilizing or modulating fluid dynamics in patients with jugulocephalic vein variant after brachiocephalic fistula.