A bilayer prototype woven vascular prosthesis with improved radial compliance

Abstract

To minimize radial compliance mismatch between native arteries and vascular prostheses over the entire blood pressure range, a biomimetic woven prosthesis sample with a bilayer wall has been developed. Poly(trimethylene terephthalate) (PTT) filaments were used as the circumferential yarns in the inner layer to increase the radial compliance of the inner wall, and poly(ethylene terephthalate) (PET) filaments formed the outer layer to provide a strong and more rigid external prosthesis wall. The two layers were joined together axially along the sample's length by a stitched weave. By means of a special weave design, the cross‐section of the tubular sample included a circumferentially crimped outer layer woven around the inner layer. This bilayer wall structure allowed only the inner layer of the sample to deform radially under small loads equivalent to low normal physiological (diastolic) blood pressures. As the load increased, the inner layer stretched until it came into contact with the outer layer. At higher (systolic) pressures, further loading caused both layers of the wall to deform together. As a result, the prosthesis showed high pressure‐induced compliance when the load was within the normal diastolic pressure range and lower compliance at higher systolic pressures.