Graft apparatus
Stents and methods of using stents are provided. Stents of the invention provide external support structure for a blood vessel segment disposed within, wherein the stents are capable of resilient radial expansion in a manner mimicking the compliance properties of an artery. The stent may be formed of a knitted or braided mesh formed so as to provide the needed compliance properties. A venous graft with the stent and a vein segment disposed within is provided, wherein graft is capable of mimicking the compliance properties of an artery. Methods of selecting stents for downsizing and methods of using the stents of the invention in downsizing and smoothening are provided. Methods of replacing a section of an artery with a venous graft including a stent of the invention are provided. Methods of reducing intimal hyperplasia in implanted vein segment in a venous graft using stents of the invention are provided.
1. A method of producing a venous graft for use in replacing a section of an artery, comprising:
providing a segment of a vein;
sheathing the segment in a generally tubular support that is in a first configuration; and
transforming the tubular support from the first configuration into a second configuration that is different from the first configuration, wherein the tubular support in the second configuration is in supportive contact with ablumenal surface of the vein segment, wherein the tubular support has a narrower diameter in the second configuration as compared to the first configuration; and wherein the tubular support in the second configuration is configured 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 , wherein the tubular support in the second configuration has resilient radial expansion and contraction characteristics that provide the graft with compliance properties mimicking compliance properties of an artery.
3. The method of claim 1 , further comprising inflating the vein and measuring one or more diameters of the inflated vein before the sheathing.
4. The method of claim 3 , further comprising selecting the tubular support from a plurality of tubular supports of various sizes based on the one or more diameters of the inflated vein.
5. The method of claim 3 , wherein the one or more diameters comprise maximum external diameter of the inflated vein.
6. The method of claim 1 , wherein the providing the segment of the vein comprises dissecting a saphenous vein.
7. The method of claim 1 , wherein the providing the segment of the vein comprises cannulating the segment of the vein.
8. The method of claim 1 , further comprising supporting the 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 sheathe the vein segment.
9. The method of claim 1 , further comprising supporting the 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.
10. The method of claim 1 , further comprising forming the tubular support from a knit wire mesh, wherein the mesh is formed with loops that alternate in size circumferentially of the support.
11. The method of claim 1 , wherein the tubular support is made of metal wire.
12. The method of claim 1 , wherein the tubular support is made of shape memory material.
13. The method of claim 12 , wherein the shape memory material comprises shape memory alloy or shape memory polymer.
14. A method of producing a venous graft for use in replacing a section of an artery, comprising:
providing a segment of a vein;
sheathing the segment in a generally tubular support that is in a first configuration;
transforming the tubular support from the first configuration into a second configuration that is different from the first configuration, wherein the tubular support in the second configuration is in supportive contact with ablumenal surface of the vein segment, wherein the tubular support has a narrower diameter in the second configuration as compared to the first configuration; and
inflating the vein and measuring one or more diameters of the inflated vein before the sheathing.
15. The method of claim 14 , wherein the tubular support in the second configuration has resilient radial expansion and contraction characteristics that provide the graft with compliance properties mimicking compliance properties of an artery.
16. The method of claim 14 , wherein the tubular support in the second configuration is configured to be sufficiently radially resilient as to provide the venous graft with a compliance ranging from 3 to 30%/100 mm Hg.
17. The method of claim 14 , further comprising selecting the tubular support from a plurality of tubular supports of various sizes based on the one or more diameters of the inflated vein.
18. The method of claim 14 , wherein the one or more diameters comprise maximum external diameter of the inflated vein.
19. The method of claim 14 , wherein the providing the segment of the vein comprises dissecting a saphenous vein.
20. The method of claim 14 , wherein the providing the segment of the vein comprises cannulating the segment of the vein.
21. The method of claim 14 , further comprising:
supporting the 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 sheathe the vein segment.
22. The method of claim 14 , further comprising:
supporting the 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.
23. The method of claim 14 , further comprising forming the tubular support from a knit wire mesh, wherein the mesh is formed with loops that alternate in size circumferentially of the support.
24. The method of claim 14 , wherein the tubular support is made of metal wire.
25. The method of claim 14 , wherein the tubular support is made of shape memory material.
26. The method of claim 25 , wherein the shape memory material comprises shape memory alloy or shape memory polymer.