Stents having radiopaque mesh

• US 9,610,181 B2
• Filed: 04/25/2016
• Issued: 04/04/2017
• Est. Priority Date: 02/22/2006
• Status: Active Grant

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Covidien LP (Medtronic Plc)
• Inventors: Zaver, Steven G., Carion, Brian S., Kusleika, Richard S.
• Primary Examiner(s): Fishback, Ashley
• Application Number:
  US15/137,364
• Publication Number:
  US 20160310300A1
• Time in Patent Office: 344 Days
• CPC Class Codes: A61F 2/0105 Open ended, i.e. legs gathered only at one side
• CPC Class Codes: A61F 2/06 Blood vessels
• CPC Class Codes: A61F 2/844 folded prior to deployment
• CPC Class Codes: A61F 2/90 characterised by a net-like or mesh-like structure
• CPC Class Codes: A61F 2002/016 made from wire-like elements
• CPC Class Codes: A61F 2002/018 made from tubes or sheets of material, e.g. by etching or laser-cutting
• CPC Class Codes: A61F 2230/0006 circular
• CPC Class Codes: A61F 2230/0067 conical
• CPC Class Codes: A61F 2250/0018 differing in elasticity, stiffness or compressibility
• CPC Class Codes: A61F 2250/0032 differing in radiographic density
• CPC Class Codes: A61F 2250/0098 radio-opaque, e.g. radio-opaque markers
• CPC Class Codes: A61F 2310/00071 Nickel or Ni-based alloys
• CPC Class Codes: A61F 2310/00137 Tungsten or W-based alloys
• CPC Class Codes: A61F 2310/00149 Platinum or Pt-based alloys

Abstract

A stent including a mesh made of strands. The mesh has at least one radiopaque strand and at least one non-radiopaque strand, and the at least one radiopaque strand and the at least one non-radiopaque strand each have different diameters. Each strand has an index of wire stiffness EI, where EI is the mathematical product of the Young'"'"'s modulus (E) and the second moment of area (I). The EI of all strands in the mesh is no more than five times the EI of the strand having the smallest EI of any of the strands.

Claims

1. A method, comprising:

expanding, against a wall of a vessel in a body of a patient, a stent comprising a mesh, the mesh comprising at least one radiopaque strand and at least one non-radiopaque strand, the at least one radiopaque strand and the at least one non-radiopaque strand each having different cross-sectional dimensions, and wherein each of the strands has an index of wire stiffness EI, where EI is the mathematical product of the Young'"'"'s modulus (E) and the second moment of area (I), and wherein the EI of each non-radiopaque strand is no more than five times the EI of a strand having the smallest EI of any of the strands.

2. The method of claim 1, wherein expanding the stent comprises positioning a mouth of the stent proximal to a side branch vessel.

3. The method of claim 1, wherein each strand has a round cross-section.

4. The method of claim 1, wherein the mesh comprises only two types of strands, a first type comprising the at least one radiopaque strand and having a cross-sectional dimension D1 and a second type comprising the at least one non-radiopaque strand and having a cross-sectional dimension D2, wherein the cross-sectional dimension D2 is greater than the cross-sectional dimension D1.

5. The method of claim 1, wherein the EI of each of the strands is no more than four times the EI of a strand having the smallest EI of any of the strands.

6. The method of claim 1, wherein the mesh comprises pores and when the mesh is at rest in free space no pore has an area more than 1.2 times the mesh pore size, the mesh pore size being the average area of five pores serially adjacent to the pore.

7. The method of claim 1, wherein the at least one radiopaque strand is an alloy of platinum and tungsten and the at least one non-radiopaque strand comprises nickel.

8. A method comprising:

expanding, against a wall of a vessel in a body of a patient, a stent comprising a mesh, the mesh comprising at least one radiopaque strand and at least one non-radiopaque strand, the at least one radiopaque strand and the at least one non-radiopaque strand each having different cross-sectional dimensions, and wherein each of the strands has an index of wire stiffness EI, where EI is the mathematical product of the Young'"'"'s modulus (E) and the second moment of area (I), and wherein the EI of each non-radiopaque strand is no more than five times the EI of each radiopaque strand.

9. The method of claim 8, wherein each strand has a round cross-section.

10. The method of claim 8, wherein the mesh comprises only two types of strands, a first type comprising the at least one radiopaque strand and having a cross-sectional dimension D1 and a second type comprising the at least one non-radiopaque strand and having a cross-sectional dimension D2, wherein the cross-sectional dimension D2 is greater than the cross-sectional dimension D1, and wherein the cross-sectional dimension D2 is no more than 1.5 times the cross-sectional dimension D1.

11. The method of claim 8, wherein the Young'"'"'s modulus of the radiopaque strand and the Young'"'"'s modulus of the non-radiopaque strand differ by 20 percent or more.

12. The method of claim 8, wherein the mesh comprises more non-radiopaque strands than radiopaque strands.

13. The method of claim 8, wherein the EI of each of the strands is no more than four times the EI of a strand having the smallest EI of any of the strands.

14. The method of claim 8, wherein the mesh comprises pores and when the mesh is at rest in free space no pore has an area more than 1.2 times the mesh pore size, the mesh pore size being the average area of five pores serially adjacent to the pore.

15. The method of claim 8, wherein the at least one radiopaque strand is an alloy of platinum and tungsten and the at least one non-radiopaque strand comprises nickel.

16. A method comprising:

expanding, against a wall of a vessel in a body of a patient, a stent comprising a mesh, the mesh comprising at least one radiopaque strand and at least one non-radiopaque strand, the at least one radiopaque strand and the at least one non-radiopaque strand each having different cross-sectional dimensions, and wherein each of the strands has an index of wire stiffness EI, where EI is the mathematical product of the Young'"'"'s modulus (E) and the second moment of area (I), and wherein the EI of each radiopaque strand is no more than five times the EI of a strand having the smallest EI of any of the strands.

17. The method of claim 16, wherein each strand has a round cross-section.

18. The method of claim 16, wherein the mesh comprises only two types of strands, a first type comprising the at least one radiopaque strand and having a cross-sectional dimension D1 and a second type comprising the at least one non-radiopaque strand and having a cross-sectional dimension D2, wherein the cross-sectional dimension D2 is greater than the cross-sectional dimension D1.

19. The method of claim 16, wherein the Young'"'"'s modulus of the at least one radiopaque strand and the Young'"'"'s modulus of the at least one non-radiopaque strand differ by 20 percent or more.

20. The method of claim 16, wherein the EI of each of the at least one non-radiopaque strand is no more than four times the EI of any radiopaque strand.

21. The method of claim 16, wherein the mesh comprises pores and when the mesh is at rest in free space no pore has an area more than 1.2 times the mesh pore size, the mesh pore size being the average area of five pores serially adjacent to the pore.

22. The method of claim 16, wherein the at least one radiopaque strand is an alloy of platinum and tungsten and the at least one non-radiopaque strand comprises nickel.