Compliant venous graft
A venous graft for replacement of a section of an artery and methods of making the graft. The graft comprises a flexible, resilient, generally tubular external support and a vein segment carried within and having an ablumenal surface in contact with and supported by the tubular support, the venous graft being capable of resilient radial expansion in a manner mimicking the radial compliance properties of an artery.
1. Method of producing a venous graft for use in replacing a section of an artery, comprising providing a segment of a vein and sheathing the segment in a generally tubular support in supportive contact with the ablumenal surface of the vein segment, the support being sufficiently flexible and radially resilient as to provide the graft with compliance properties mimicking the compliance properties of an artery, wherein said generally tubular support is chosen to be sufficiently radially resilient as to provide the venous graft with a compliance ranging from 3 to 30%/100 mm Hg.
2. The method of claim 1 including the step of cutting said venous graft from a longer section of vein sheathed in said tubular support, the ends of the vein and tubular support of the venous graft being coextensive.
3. The method of claim 1 including the step of supporting said generally tubular support upon an exterior surface of an applicator having an internal passage within which is positioned the vein segment, and removing the applicator to permit the tubular support to come into supportive contact with the ablumenal surface of the vein segment.
4. The method of claim 3 wherein said tubular support is axially resilient, the method including the step of controlling axial dimension changes of the tubular support as the support comes into supportive contact with the vein segment to provide the venous graft with said compliance properties.
5. The method of claim 4 including the step of providing the tubular support with an axially extending, relatively inextensible element that restrains the tubular support from unwanted axial extension.
6. The method of claim 5 wherein said inextensible element comprises a flexible fiber positioned within the tubular support and between the tubular support and the ablumenal surface of the vein segment.
7. The method of claim 6 wherein the flexible fiber is a wire joined to the interior of the tubular support.
8. The method of claim 1 including the step of supporting said generally tubular support upon an exterior surface of an applicator having an internal passage, and, while passing the vein segment from within the applicator passage, drawing the tubular support onto the surface of the vein segment.
9. The method of claim 1 including the step of bonding the ablumenal surface of the vein segment to the tubular support.
10. The method of claim 1 including forming said tubular support from a knit wire mesh, wherein said mesh is formed with loops that alternate in size circumferentially of the support.