Compliant blood vessel graft
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 for selecting a stent for placement at an ablumenal surface of a vein of a venous graft, the method comprising:
providing the vein to be measured;
measuring a minimum outer diameter and a maximum outer diameter of the vein;
selecting a maximum amount of diametrical downsizing for the vein and a minimum amount of diametrical downsizing for the vein, the diametrical downsizing being effected by resilient compliance of the stent placed at the ablumenal surface, said stent providing resilient compliance in the range of 3 to 30%/100 mm Hg;
calculating a range of inner diameters of stents that provide an amount of diametrical downsizing between the selected maximum amount and the selected minimum amount;
selecting a single stent having an inner diameter that falls within the calculated range.
2. The method according to claim 1 , further comprising calculating a degree of downsizing for smoothening the vein.
3. The method according to claim 2 , wherein said smoothening comprises altering an outside diameter of at least one part of the vein to be substantially the same as another part of the vein.
4. The method according to claim 1 , wherein the single stent is the smallest possible stent within the range, resulting in maximum downsizing.
5. The method according to claim 1 , wherein the single stent is the largest possible stent within the range, resulting in minimum downsizing.
6. The method according to claim 5 , wherein the stent has a diameter of between about 3.0 mm and 4.0 mm.
7. The method according to claim 1 , wherein the stent has a diameter of between about 2.7 mm and about 4.0 mm.
8. The method according to claim 1 , wherein the maximum amount of downsizing for the vein is the degree of downsizing for substantially smoothening the vein.
9. The method according to claim 8 , wherein said substantially smoothening the vein includes smoothening irregularities in the vein.
10. The method according to claim 1 wherein the maximum amount of downsizing of the vein is up to about 40%.
11. The method according to claim 10 wherein a largest inner diameter of the range of stent inner diameters is smaller than or equal to the minimum outer diameter of the vein.