Computational model of thrombosis in cerebral aneurysms for predicting clotting outcomes in flow diverter treated patient-derived geometries validated with novel PIV-based ln vitro clotting flow experiment

Hume, Struan Robertson

Computational model of thrombosis in cerebral aneurysms for predicting clotting outcomes in flow diverter treated patient-derived geometries validated with novel PIV-based ln vitro clotting flow experiment

Thesis / Dissertation

2024

Publisher

University of Cape Town

Department

Department of Human Biology

Faculty

Faculty of Health Sciences

Abstract

There are a growing number of computational models of thrombosis in cerebral aneurysms designed with consideration towards clinical use and research. Many thrombosis models include complicated clotting mechanisms, which can be computationally expensive, and present a challenge to comprehensively validate in vitro due in part to the complexity of adequately measuring the ongoing interaction between flow and clot-growth; a key factor in predicting aneurysm-occlusion after surgical placement of a stent. To this end, a pulsatile-flow direct thrombosis-model has been developed towards use in a clinical environment to predict thrombosis outcomes in patient-specific cerebral aneurysm cases with and without a flow diverter, and is validated at each 0.05s timestep using a novel PIV-based (Particle Image Velocimetry) in vitro clotting flow experiment that simultaneously captures motion of a fibrin clot strand and surrounding flow within an idealized aneurysm flow vessel. The validated pulsatile-flow fibrin clot-model produces plausible clotting outcomes in each of the patient-specific cerebral aneurysm cases, with and without flow diverters, dependent upon the classification and size of cerebral aneurysm in question. The novel PIV-based in vitro clotting flow experiment demonstrates that fibrin clotting and flow may be measured simultaneously using PIV techniques. In cross-referencing the results of multiple simulations and flow experiments performed for this thesis with one another and to literature, the combined studies indicate two potentially important considerations for future direct thrombosis models of cerebral aneurysms. These include directional clot growth in accordance with the alignment of fibrin strands due to periodically high physiological flow rates, and the significance of the non-Newtonian features of blood for the modelling of physiological flow and wall boundaries in major cerebral arteries, although the results of a small sample of experiments is far from conclusive and further study in these areas is required.

Keywords

Computational Models

Reference:

Collections

PhD / Doctoral

Full item page