Hemodynamics of end-to-end anastomosis bypass: on the specific influnce of a stenosis in the host artery

Valérie Deplano (1) , Christine Bertolotti (1)

1 IRPHE - Institut de Recherche sur les Phénomènes Hors Equilibre

Local hemodynamics is implicated in the failure of bypass graft surgery. Intimal thickening has been shown to occur at specific sites, namely the floor, the heel, the toe and the suture line. Nevertheless, the recipient artery has often been repre-sented in the literature as a simple flow rate reduction or as a complete obstruc-tion neglecting the perturbing presence of the stenosis. In addition, severe as well as moderate constrictions are sometimes bypassed without taking into account an existing residual flow through the host artery. The purpose of this chapter is therefore to investigate how competitive flows issued from the graft and the dis-eased artery could interact together, and thus to explain the restenosis process at an early stage. The velocity flow rates are issued from in vivo measurements for patients who had undergone coronary bypass surgery approximately three weeks before. 3D unsteady flows through idealized coronary bypass anastomoses are modeled by the finite element method. The influence of the inflows, and of the shape of the stenosis, are notably discussed. The experimental Doppler velocity fields corroborate well the numerical results. The post-stenotic recirculation zone is demonstrated to interact with the graft inflow during the cardiac cycle. These disturbed flow patterns due to the presence of a stenosis may have harmful con-sequences in terms of graft patency

Domaines: Biomécanique [physics.med-ph]; Biomécanique [physics.med-ph]

Valérie Deplano, Christine Bertolotti. Hemodynamics of end-to-end anastomosis bypass: on the specific influnce of a stenosis in the host artery. Tura A. Vascular grafts. Experiment and modelling, WIT Press, Chap. 10, p. 375-422, 2003, ISBN : 1-85312-900-3, Series : Advances in Fluid Mechanics Vol 34. ⟨hal-00085261⟩