| 摘要 |
1505591 Vascular prosthesis D GOLDFARB 14 Feb 1975 [24 Oct 1974] 6347/75 Heading A5R [Also in Division C3] A tubular prosthetic vascular graft of expanded polytetrafluoroethylene has a microscopic structure consisting of irregularly spaced, generally ellipsoidal nodes of P.T.F.E. connected to each other by fibrils, the wall 1 of the graft having a thickness of between 0.2 and 0.8mm, the nodes being substantially uniformly distributed with an average separation of between 6 and 80 microns so that the passage of blood through the graft is prevented, and the average density of the P.T.F.E, being from 0.2 to 0.5gms/ml. whereby it is stated that controlled cellular ingrowth may occur through the wall 1 to promote and nourish an internal layer of cells 7 and to anchor the graft to adjacent tissue. The average inside diameter of the graft is less .than 40mm and may be less than 8mm down to 2mm. The graft has a tensile strength of between 2500 and 6500psi. A tapered graft may be provided having a diameter of between 5 and 8mm at one end and a diameter of between 2 and 6mm at the other end. The minor axis of each node is less than 18 macrons and the major axis of the nodes are arranged radially with respect to the tubular graft. |
