title: The mechanical properties of glutaraldehyde stabilized human umbilical vein measured in vivo.
abstract: Vascular prostheses, when used to bypass the femoral and popliteal arteries, and particularly if the bypass is made to the distal part of the tibial arteries, seldom remain patent, or if they do then for only a limited period of time. Femorotibial bypass with modified human umbilical vein is relatively successful in selected patients and one explanation may be that it resembles human arteries more than other prostheses. We have developed a method of calculating the asymptotic phase speed, from the propagation constant and from this the characteristic impedance of a bypass (all of which characterize viscoelastic behaviour). Calculations were made on measurements of pressure made in vivo. Twenty patients who had a femorotibial bypass, using glutaraldehyde stabilized umbilical vein, were studied and, from measurements of pressure made at operation, we calculated the asymptotic phase speed and the characteristic impedance of the prostheses. Results show that the viscoelastic properties of newly implanted umbilical vein are comparable to those of autogenous saphenous vein.
mesh_terms: D001696:Biomechanical Phenomena; D001705:Bioprosthesis; D001807:Blood Vessel Prosthesis; D004548:Elasticity; D006801:Humans; D012212:Rheology; D014471:Umbilical Veins / Q000637:transplantation; D014783:Viscosity