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Quantifying the hemodynamic characteristics of an arteriovenous fistula used for hemodialysis

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dc.contributor.advisor Griffin, Philip
dc.contributor.advisor Walsh, Michael T. Browne, Leonard D. 2015-12-16T16:05:19Z 2015-12-16T16:05:19Z 2015
dc.description peer-reviewed en_US
dc.description.abstract Chronic kidney disease refers to an irreversible, progressive reduction of the renal function of kidneys. When there is a significant loss of renal function a replacement therapy is sought. A kidney transplant is the optimal replacement. However, the demand for kidney transplantation exceeds the supply of transplantable organs and most patients will never receive a kidney transplant. As a consequence, these patients are often referred to hemodialysis to filter blood. To facilitate efficient and adequate dialysis an access capable of supplying high flow rates is required. An arteriovenous fistula is the access modality of choice for patients requiring hemodialysis. This access is formed from the anastomosis of an artery and vein which generates the high flow rates needed for efficient dialysis. Despite the preference of this access, the modality suffers from drastically poor primary and secondary patency rates which necessitate urgent improvement. Following the creation of the access a period of time is required to ensure adequate remodelling and maturation of the fistula occurs prior to cannulation. Non-maturation contributes significantly to the dismal patency rates of this access. Impaired outward remodelling and aggressive intimal hyperplasia are both considered to contribute to fistula non-maturation and the abnormal hemodynamics arising from fistula creation are believed to provide a stimulus for both facets of remodelling. Increasing an understanding of this relationship forms the primary focus of this dissertation. The primary aim of this thesis is to accurately characterise the hemodynamics of an arteriovenous fistula using experimental and numerical models. An unsteady incompressible Navier Stokes solver strategy was implemented and validated as a reliable computational approach to accurately estimate the pressure drop across a representative fistula. Both in-vitro and numerical models demonstrated a quadratic relationship between pressure drop and flow rate across the anastomosis. Instabilities were found to develop within the anastomosis and generated high frequency oscillations of the pressure drop signal. These instabilities were most prevalent during the end of the systole and throughout diastole phase of the cycle. en_US
dc.language.iso eng en_US
dc.publisher University of Limerick en_US
dc.subject chronic kidney disease en_US
dc.subject hemodialysis en_US
dc.subject arteriovenous fistula en_US
dc.title Quantifying the hemodynamic characteristics of an arteriovenous fistula used for hemodialysis en_US
dc.type info:eu-repo/semantics/doctoralThesis en_US
dc.type.supercollection all_ul_research en_US
dc.type.supercollection ul_published_reviewed en_US
dc.type.supercollection ul_theses_dissertations en_US
dc.contributor.sponsor IRC en_US
dc.rights.accessrights info:eu-repo/semantics/openAccess en_US

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