MECHANICAL-PROPERTIES OF SYNTHETIC ARTERIAL GRAFTS

Stress-strain diagrams and stress relaxation curves of knitted and woven grafts of both Dacron and Teflon were examined using a tensile testing instrument, and were compared with those of canine aortic trees. Circumferential distensibilities were much smaller in synthetic arterial grafts than in any aortic portions, while no significant difference in longitudinal distensibilities was discerned between grafts and aortic portions. Viscoelasticities of synthetic arterial grafts depend largely upon the type of synthetic material employed, not upon the type of weave, circular crimps or cut-out directions. Viscoelasticities of Dacron grafts correspond well with those of proximal aortic portions, whereas Teflon grafts have no viscoelastic resemblance to any aortic portions. Synthetic arterial grafts after three weeks' implantation in the subcutaneous tissue of hindlimb demonstrated marked reduction in longitudinal distensiblities, but no change in circumferential ones, indicating the mechanical effect of fibrous tissue ingrowth which occurred through the interstices of the implanted grafts. © 1979.