Development of biomechanically compliant arterial grafts

In the current project, the focus has been on designing and producing small diameter woven grafts which have stretch in both the longitudinal and transverse directions and on studying their in vitro performance. For construction of grafts, a model narrow fabric loom was set up. A polyester yarn containing 34 filaments each of 3.2 dtex was used as the warp. For weft insertion, a number of yarns based on polyurethane, differing in size, structure, and composition, and, thus, in properties, were procured. The properties of a woven fabric are known to vary with the denier and the properties of the yarn, the weave design, the weave tightness, and the heat setting treatment used to finish the fabric for the study. Hence, several levels of each of these parameters were incorporated to develop structures (sixty-four). The longitudinal and transverse properties of the grafts so produced were characterized using special in vitro methods and related to the differences In yarn properties and weave construction and tightness. The preliminary results obtained indicate that the grafts have transverse compliance which can be controlled by altering the yarn and fabric construction parameters. The work is in progress and a more complete study is expected to be available at the time of the conference.