Minimisation of the wall shear stress gradients in bypass grafts anastomoses using meshless CFD and genetic algorithms optimisation

    Authors

    Z. El Zahab; E. Divo;A. Kassab

    Comments

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    Abbreviated Journal Title

    Comput. Methods Biomech. Biomed. Eng.

    Keywords

    end-to-side distal anastomoses; intimal hyperplasia; shape optimisation; meshless CFD; genetic algorithms; INTIMAL HYPERPLASIA; FEMOROPOPLITEAL BYPASS; COMPLIANCE MISMATCH; DISTAL; ANASTOMOSES; SHAPE OPTIMIZATION; ARTERIAL BYPASS; FLOW PATTERNS; VISCOUS; FLOWS; IN-VIVO; MODEL; Computer Science, Interdisciplinary Applications; Engineering, ; Biomedical

    Abstract

    The wall shear stress (WSS) spatial and temporal gradients are two hemodynamics parameters correlated with endothelial damage. Those two gradients become well pronounced in a bypass graft anastomosis geometry where the blood flow patterns are quite disturbed. The WSS gradient minimisation on the host artery floor can be achieved by optimising the anastomosis shape and hence may lead to an improved long-term post-surgical performance of the graft. The anastomosis shape optimisation can be executed via an integrated computational tool comprised of a meshless computational fluid dynamics (CFD) solver and a genetic algorithm (GA) shape optimiser. The meshless CFD solver serves to evaluate the WSS gradients and the GA optimiser serves to search for the end-to-side distal anastomosis (ETSDA) optimal shape that best minimises those gradients. We utilise a meshless CFD method to resolve hemodynamics and a GA for the purpose of optimisation. We consider three different anastomotic models: the conventional ETSDA, the Miller Cuff ETSDA and the hood ETSDA. The results reported herein demonstrate that the graft calibre should always be maximised whether a conventional or Miller Cuff ETSDA model is utilised. Also, it was noted that the Miller Cuff height should be minimised. The choice of an optimal anastomotic angle should be optimised to achieve a compromise between the concurrent minimisations of both the spatial WSS gradient and the temporal WSS gradient.

    Journal Title

    Computer Methods in Biomechanics and Biomedical Engineering

    Volume

    13

    Issue/Number

    1

    Publication Date

    1-1-2010

    Document Type

    Article

    Language

    English

    First Page

    35

    Last Page

    47

    WOS Identifier

    WOS:000274221500004

    ISSN

    1025-5842

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