Affiliations: Department of Mechanical Engineering, Polytechnic
School, University of São Paulo, 2231 Av. Prof. Mello Moraes, Cidade
Universitária, CEP: 05508-900, Brazil. E-mail: kleiber@usp.br | Department of Mechanical Engineering, Polytechnic
School, University of São Paulo, 2231 Av. Prof. Mello Moraes, Cidade
Universitária, CEP: 05508-900, Brazil. E-mail: jportiz@usp.br.
Mauá Institute of Technology, Engineering School, S.C. do Sul, e-mail:
ortiz@maua.br
Abstract: The arteriovenous fistula (AVF) is characterized by enhanced blood
flow and is the most widely used vascular access for chronic haemodialysis
(Sivanesan et al., 1998). A large proportion of the AVF late failures are
related to local haemodynamics (Sivanesan et al., 1999a). As in AVF, blood flow
dynamics plays an important role in growth, rupture, and surgical treatment of
aneurysm. Several techniques have been used to study the flow patterns in
simplified models of vascular anastomose and aneurysm. In the present
investigation, Computational Fluid Dynamics (CFD) is used to analyze the flow
patterns in AVF and aneurysm through the velocity waveform obtained from
experimental surgeries in dogs (Galego et al., 2000), as well as
intra-operative blood flow recordings of patients with radiocephalic AVF
(Sivanesan et al., 1999b) and physiological pulses (Aires, 1991), respectively.
The flow patterns in AVF for dog and patient surgeries data are qualitatively
similar. Perturbation, recirculation and separation zones appeared during
cardiac cycle, and these were intensified in the diastole phase for the AVF and
aneurysm models. The values of wall shear stress presented in this
investigation of AVF and aneurysm models oscillated in the range that can both
cause damage to endothelial cells and develop atherosclerosis.
