Some Mechanical/Hydrodynamical Problems of Contemporary Vascular Grafts

In view of the importance of properly matching vascular grafts and replaced arteries, we measured some mechanical properties of a set of eleven vascular grafts. The deformation response of inflated grafts for a set of Czechoslovak-made warp and weft knitted grafts was also measured on a special experimental device. A simple two-parameter model describing the stress-strain behavior of the grafts is given. Proper pre-elongation of the graft during implantation is important. From the hydrodynamic point of view it is essential to optimize the size and shape of the crimping, especially for small-diameter grafts. Our experiments indicate that the warp knitted grafts are more distensible than the weft knitted ones, but they are all more rigid than the replaced arteries.