Computational model‐based hemodynamic comparisons of traditional and modified idealized models of autologous radiocephalic fistula

• Published in: International journal for numerical methods in biomedical engineering 2024-10, Vol.40 (10), p.e3856-n/a
• Main Authors: Wang, Fan, Wang, Baohui, Guo, Jinfeng, Zhang, Tian, Mu, Weina, Liu, Chunhui
• Format: Article
• Language: English
• Subjects: Anastomosis; autologous arteriovenous fistula; Blood flow; Computational fluid dynamics; Computer applications; Error analysis; Fistula; Fistulae; Flow velocity; Fluid dynamics; Hemodialysis; Hemodynamics; Hydrodynamics; Hyperplasia; In vivo methods and tests; model modification; Shear stress
• ISSN: 2040-7939; 2040-7947; 2040-7947
• DOI: 10.1002/cnm.3856

Autologous arteriovenous fistula (AVF) is a commonly used vascular access (VA) for hemodialysis, and hemodynamic changes are one of the main factors for its failure. To explore the effect of geometry on the hemodynamics in the AVF, a modified model is built with a gradual and smooth turn at the anastomosis and is compared with the traditional model, which has an abrupt sharp turn at the anastomisis. Transient computational fluid dynamics (CFD) simulations were performed for the comparison and analysis of the hemodynamic fields of the two models at different stages of the pulse cycle. The results showed that the low shear stress region and high oscillatory shear stress region in the modified AVF model coincided with regions of intimal hyperplasia that have been identified by previous studies. A comparison with the blood flow velocities measured in vivo was performed, and the error between the simulation results and the medical data was reduced by 22% in the modified model, which verifies the rationality and utility of the modified model. A modified autologous arteriovenous fistula model with a gradual and smooth turn at the anastomosis is constructed in comparison to the traditional model. Transient computational fluid dynamics simulations were conducted to compare the hemodynamics between the two models. The modified model exhibits good agreement with previous studies in terms of low shear stress distribution and high oscillatory shear stress distribution. The error between the simulation results and the in vivo measured data was reduced by 22% in the modified model.