Method of forming a non-circular stent

• US 8,007,605 B2
• Filed: 01/30/2007
• Issued: 08/30/2011
• Est. Priority Date: 09/03/2003
• Status: Active Grant

• Current Assignee: Bolton Medical, Inc. (Terumo Corporation)
• Original Assignee: Bolton Medical, Inc. (Terumo Corporation)
• Inventors: Berra, Humberto, Arbefeuille, Samuel
• Primary Examiner(s): WYSZOMIERSKI, GEORGE P
• Application Number:
  US11/699,701
• Publication Number:
  US 20070163668A1
• Time in Patent Office: 1,673 Days
• Field of Search: 148/563, 623/1.18, 623/1.22
• US Class Current: 148/563
• CPC Class Codes: A61F 2/07 Stent-grafts
• CPC Class Codes: A61F 2/89 the wire-like elements comprising two or more adjacent rings flexibly connected by separate members
• CPC Class Codes: A61F 2/95 Instruments specially adapted for placement or removal of stents or stent-grafts
• CPC Class Codes: A61F 2/9517 handle assemblies therefor
• CPC Class Codes: A61F 2/966 with relative longitudinal movement between outer sleeve and prosthesis, e.g. using a push rod
• CPC Class Codes: A61F 2002/075 the stent being loosely attached to the graft material, e.g. by stitching
• CPC Class Codes: A61F 2002/828 Means for connecting a plurality of stents allowing flexibility of the whole structure
• CPC Class Codes: A61F 2002/9505 having retaining means other than an outer sleeve, e.g. male-female connector between stent and instrument
• CPC Class Codes: A61F 2002/9511 the retaining means being filaments or wires
• CPC Class Codes: A61F 2002/9528 for retrieval of stents
• CPC Class Codes: A61F 2002/9665 with additional retaining means
• CPC Class Codes: A61F 2210/0014 using shape memory or superelastic materials, e.g. nitinol
• CPC Class Codes: A61F 2230/0091 helically-coiled or spirally-coiled, i.e. having a 2-D spiral cross-section
• CPC Class Codes: A61F 2250/0098 radio-opaque, e.g. radio-opaque markers
• CPC Class Codes: A61M 25/0105 Steering means as part of the catheter or advancing means; Markers for positioning systems for detection of markers A61B
• CPC Class Codes: A61M 25/0108 using radio-opaque or ultrasound markers
• CPC Class Codes: Y10T 29/49799 Providing transitory integral holding or handling portion
• CPC Class Codes: Y10T 74/18392 Crank, pitman, and crank

Abstract

A method for manufacturing a stent, includes the steps of winding stent wire around the outer surface of a longitudinal axis of a mandrel into a desired final shape that is polygonal in an elevation orthogonal to the longitudinal axis, and forming a stent by setting the wound stent wire in the desired polygonal final shape. The outside diameter of the stent formed will be in co-columnar apposition with a blood vessel in which it is implanted. The mandrel employed in the methods can have a multiple-sided outer surface and a longitudinal axis.

Claims

1. A method for manufacturing a stent, comprising the steps of:

a) winding stent wire around an outer surface of a longitudinal axis of a mandrel having a polygonal cross-sectional shape into a desired final shape that is polygonal in an elevation orthogonal to the longitudinal axis; and

b) forming a stent by setting the wound stent wire in the desired polygonal final shape, whereby the outside diameter of the stent will be in co-columnar apposition with a blood vessel in which it is implanted.

2. The method according to claim 1, wherein the mandrel further includes flat sections and rounded edge portions between the flat sections.

3. The method according to claim 2, further including carrying out the stent forming step by setting the stent wire to have rounded edges corresponding to the rounded edge portions of the mandrel and with flat sides corresponding to the flat sections of the mandrel.

4. The method according to claim 1, further including the steps of:

c) placing pins on the outer surface of the mandrel longitudinally offset from one another and corresponding to desired Z-stent apex locations; and

d) forming Z-stent apices by winding the stent wire around the pins.

5. The method according to claim 4, wherein the pins are placed on the mandrel to protrude perpendicularly from the outside surface of the mandrel.

6. The method according to claim 2, further including the steps of:

c) placing pins on at least some of the rounded edge portions of the mandrel longitudinally offset from one another and corresponding to desired Z-stent apex locations; and

d) forming Z-stent apices by winding the stent wire around the pins.

7. The method according to claim 6,

wherein the pins are placed at each of the rounded edge portions of the mandrel and the stent is set with substantially linear struts lying flat against the flat sections of the mandrel.

8. The method according to claim 1,

wherein the mandrel has a dodecahedron shape and

a Z-stent having six proximal and six distal apices is formed.

9. The method according to claim 1, further including the step of fastening two ends of the stent wire to one another to complete the stent.

10. The method according to claim 1, wherein the stent wire is initially wound around the outer surface of the longitudinal axis of the mandrel as a cold-drawn shape-memory wire and the stent is formed by heat-treatment.

11. The method according to claim 10, wherein the heat-treatment includes exposing the shape-memory wire to a heat-setting temperature for a period of time with subsequent quenching as required to shape set the shape-memory wire to the then-existing shape of the wire on the mandrel and obtain superelastic mechanical characteristics of the shape-memory wire.

12. The method according to claim 1, wherein the stent is formed by exposing the stent wire to a process that shapes the wire to the then-existing shape of the wire on the mandrel selected from at least one of the group consisting of a mechanical process, a thermal process, and a chemical process.

13. A method for manufacturing a stent, comprising the steps of:

a) winding a stent wire around an outer surface of a longitudinal axis of a mandrel having a multiple-sided outer surface into a desired final shape substantially corresponding to a shape of the outer surface; and

b) forming a stent by setting the wound stent wire into the desired final shape, whereby the outside diameter of the stent will be in co-columnar apposition with a blood vessel in which it is implanted.

14. The method according to claim 13, wherein the mandrel includes flat sections and rounded edge portions between the flat sections and the stent is formed by setting the stent wire to have rounded edges corresponding to the rounded edge portions of the mandrel and with flat sides corresponding to the flat sections of the mandrel.

15. The method according to claim 14, further including the steps of:

c) placing pins on the outer surface of the mandrel protruding perpendicularly therefrom and being longitudinally offset from one another to correspond with desired Z-stent apex locations; and

d) forming Z-stent apices of the stent by winding the stent wire around the pins.

16. The method according to claim 15, wherein the pins are placed on each of the rounded edge portions of the mandrel.

17. The method according to claim 13, further including the step of fastening two ends of the stent wire to one another to complete the stent.

18. The method according to claim 13, wherein the stent wire is initially wound around the outer surface of the longitudinal axis of the mandrel as a cold-drawn shape-memory wire and the stent is formed by heat-treatment.

19. The method according to claim 18, wherein the heat-treatment includes exposing the shape-memory wire to a heat-setting temperature for a period of time with subsequent quenching as required to shape set the shape-memory wire to the then-existing shape of the wire on the mandrel and obtain superelastic mechanical characteristics of the shape-memory wire.

20. The method according to claim 13, wherein the stent is formed by exposing the stent wire to a process that shapes the wire to the then-existing shape of the wire on the mandrel selected from at least one of the group consisting of a mechanical process, a thermal process, and a chemical process.