Abstract: A vascular graft comprising a proximal section, iliac distal legs and a bifurcation blending section (7) between the proximal section and the distal legs. The cross-sectional area of the proximal section at the bifurcation point is less than or equal to the sum of the two cross sectional areas of both iliac legs. The blending section (7) generates a smooth transition from the proximal section to both iliac legs which minimizes wave reflections by ensuring that the area ratio at the bifurcated junction (7) is as close to unity or greater than unity as possible. The blending section (7) defines a first lumen for fluid flow from the proximal section into the first distal leg, and a separate second lumen for fluid flow from the proximal section into the second distal leg. The two lumen are separated by means of a gradual flow which separates the fluid flow from the proximal section into each lumen.

Abstract: A modelling system (1) comprises a blood vessel simulating model (2) connected to a pump system (3) and mounted in the field of view of a polariscope system (4) and a camera system (7). The model (2) is mounted on an adjustable stand (5). The blood vessel simulating model (2) is connected to the pump system by outlet control and access valves (10). The blood vessel simulating model (2) is connected to the pump system (3) by a clip (9). A pressure sensor (8) is provided to monitor pressure levels within the model (2). The pump system (3), pressure sensor (8), polariscope (4) and camera (7) are controlled by controllers (39, 11, 13). The adjustable stand (5) is movable to facilitate rotation, change of orientation, change of level of one end of the model with respect to the other end, and bending of the blood vessel simulating model (2). The pump system (3) circulates a liquid to the model (2) to simulate blood flow in the model.