A clinical role for fluid dynamics modelling of arteriovenous fistulae
type: CreativeWork
description: Disease of the vascular system often manifests through inward remodelling, forming a narrowing in the vessel, called a stenosis. The appearance of stenoses in certain critical vessels, such as those in the heart and brain can have morbid consequences as the vessels approach total occlusion. This disease process is due to inflammatory responses instigated by endothelial cells at the inner wall surface, which transduce wall shear stress from the blood flow in their regulatory capacity, driving vascular remodelling in response to changes in flow. In arteriovenous fistulae (AVFs), formed as a vascular access for hemodialysis, rates of stenoses are very high. This is understood to be due to the unusual geometric configuration, in combination with supraphysiological flowrates. Significant disturbance to the flow occurs at the anastomosis, which propagates into the juxta-anastomotic vein segment, a region where stenosis is often observed in AVFs. This thesis sought to identify pathogenic WSS patterns within AVFs and improve clinical monitoring through patient-specific CFD (PS-CFD) modelling. This began with the development of an ultrasound-based 3D geometry scanning methodology, as well as a data pipeline for generation of PS-CFD models. A diverse range of patients with AVFs were scanned during a one year period, from which eight different patient cases were formed, capturing events across multiple scans over varying timelines. Longitudinal analysis of these scans was carried out, with four exhibiting signs of disease development between the scans, and the remaining four involving alterations following stenting procedures. Within the four cases of disease, WSS behaviours with transient multidirectionality over the pulse cycle, identified through the transWSS metric, were found to localise in regions where inward remodelling occurred. In two cases where stenosis was seen to progress in severity, transWSS grew in magnitude, whilst the other cases with much less severe stenos…
abstract: Disease of the vascular system often manifests through inward remodelling, forming a narrowing in the vessel, called a stenosis. The appearance of stenoses in certain critical vessels, such as those in the heart and brain can have morbid consequences as the vessels approach total occlusion. This disease process is due to inflammatory responses instigated by endothelial cells at the inner wall surface, which transduce wall shear stress from the blood flow in their regulatory capacity, driving vascular remodelling in response to changes in flow. In arteriovenous fistulae (AVFs), formed as a vascular access for hemodialysis, rates of stenoses are very high. This is understood to be due to the unusual geometric configuration, in combination with supraphysiological flowrates. Significant disturbance to the flow occurs at the anastomosis, which propagates into the juxta-anastomotic vein segment, a region where stenosis is often observed in AVFs. This thesis sought to identify pathogenic WSS patterns within AVFs and improve clinical monitoring through patient-specific CFD (PS-CFD) modelling. This began with the development of an ultrasound-based 3D geometry scanning methodology, as well as a data pipeline for generation of PS-CFD models. A diverse range of patients with AVFs were scanned during a one year period, from which eight different patient cases were formed, capturing events across multiple scans over varying timelines. Longitudinal analysis of these scans was carried out, with four exhibiting signs of disease development between the scans, and the remaining four involving alterations following stenting procedures. Within the four cases of disease, WSS behaviours with transient multidirectionality over the pulse cycle, identified through the transWSS metric, were found to localise in regions where inward remodelling occurred. In two cases where stenosis was seen to progress in severity, transWSS grew in magnitude, whilst the other cases with much less severe stenos…
author: Carroll, John
language: EN
keywords: Computational Fluid Dynamics, Vascular Disease, Arteriovenous Fistula, Wall Shear Stress, 3D Ultrasound, Patient-Specific, Stent
license: https://purl.org/coar/access_right/c_abf2
license: https://creativecommons.org/licenses/by-nc-nd/3.0/au/
date published: 2018
date modified: 2026-07-24T05:32:40Z
provider: University of New South Wales
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: UNSW, Sydney

PropertyValue
property ID: Handle
value: http://hdl.handle.net/1959.4/64227

PropertyValue
property ID: DOI
value: 10.26190/unsworks/21488