Banca de QUALIFICAÇÃO: WILLYAM BRITO DE ALMEIDA SANTOS

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : WILLYAM BRITO DE ALMEIDA SANTOS
DATE: 07/02/2020
TIME: 14:30
LOCAL: Auditório do CTEC - UFRN
TITLE:

ANALYSIS OF PULSATILE FLOW IN ARTERIOVENOUS FISTULA WITH VARIATION OF THE ANASTOMOSIS ANGLE IN VITRO AND IN SILICO

KEY WORDS:

Arteriovenous fistula, pulsatile flow, anastomosis angle

PAGES: 153
BIG AREA: Engenharias
AREA: Engenharia Mecânica
SUMMARY:

Arteriovenous fistula (AVF) is a direct connection between an arterial and a venous vessel, used as the most common vascular access (AV) for patients undergoing hemodialysis (HD). The preparation of AVF causes non-physiological conditions of blood flow, inducing disturbances in the flow such as recirculation zones, stagnation points, high, low and oscillatory shear stress levels. These disorders are associated with the development of pathologies that promote stenosis in the vessel, which can compromise blood flow or even the loss of AVF. There are few studies on AVF in the literature that determine the flow field and its implications on the wall, for different anastomosis angles. An experimental bench was built to provide pulsatile flow in AVF models in vitro and in silico. The AVF was modeled three-dimensionally with angles of anastomosis varying between 30 ° and 150 °. Tests were carried out on the experimental bench to analyze the pressure profile. Other tests, with permanent flows, on AVF models with an anastomosis angle of 30 ° were also performed. The pressure profile for pulsatile flow demonstrates agreement with the blood pressure pulse in the literature, small time adjustments always necessary. The in vitro model of the FAV, printed by a 3D printer, was tested applying pressures from 0 to 45 kPa and no leaks were observed. The pressures in the anastomosis region of the in vitro model, for permanent flow, showed an increasing behavior due to the flow. The in silico model showed good agreement with the in vitro model, with a maximum difference of 4.8%, the others being less than 1.9%. The pressure distribution in the AVF wall showed maximum values in the external vein wall near the junction distal anastomotic, while low pressure levels were identified in the internal vein wall in the region of the proximal anastomotic junction. In correlation with the pressure distribution, the velocity field presented regions of stagnation and recirculation zones. To date, 52% of the project has been developed. In future works, it will be a working fluid implement with specific mass and adequate viscosity, installation of the temperature control system on the experimental bench and preparation of analysis of the AVF models with different anatomical angles.

BANKING MEMBERS:
Presidente - 2550377 - THERCIO HENRIQUE DE CARVALHO COSTA
Externo ao Programa - 2654020 - KLEIBER LIMA DE BESSA
Externo à Instituição - JAYME PINTO ORTIZ - USP