Scaffolds having a radiopaque marker and methods for attaching a marker to a scaffold

• US 10,610,387 B2
• Filed: 06/06/2017
• Issued: 04/07/2020
• Est. Priority Date: 06/12/2015
• Status: Active Grant

• Current Assignee: Abbott Cardiovascular Systems Incorporated (Abbott Laboratories)
• Original Assignee: Abbott Cardiovascular Systems Incorporated (Abbott Laboratories)
• Inventors: Lumauig, Rommel, Harrington, Joel, Abunassar, Chad, Hart, David D., Ciurea, Cornel I., Ritchie, Mark A., King, Jay A., McCoy, Jill
• Primary Examiner(s): Stewart, Jason-Dennis N
• Application Number:
  US15/615,751
• Publication Number:
  US 20170333233A1
• Time in Patent Office: 1,036 Days
• CPC Class Codes: A61F 2/844 folded prior to deployment
• CPC Class Codes: A61F 2/86 Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure
• 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 2/915 with bands having a meander structure, adjacent bands being connected to each other
• CPC Class Codes: A61F 2002/3008 radio-opaque, e.g. radio-opaque markers
• CPC Class Codes: A61F 2002/91575 connected peak to trough
• CPC Class Codes: A61F 2210/0014 using shape memory or superelastic materials, e.g. nitinol
• CPC Class Codes: A61F 2220/0033 made by longitudinally pushing a protrusion into a complementary-shaped recess, e.g. held by friction fit
• CPC Class Codes: A61F 2230/0026 trapezoidal
• CPC Class Codes: A61F 2230/0069 cylindrical
• CPC Class Codes: A61F 2240/001 Designing or manufacturing processes
• CPC Class Codes: A61F 2250/0098 radio-opaque, e.g. radio-opaque markers
• CPC Class Codes: B21J 15/02 Riveting procedures
• CPC Class Codes: B21J 15/04 Riveting hollow rivets mechanically
• CPC Class Codes: B21J 15/14 specially adapted for riveting specific articles, e.g. brake lining machines
• CPC Class Codes: Y10T 29/49993 Filling of opening

Abstract

A scaffold includes a radiopaque marker connected to a strut. The marker is retained within the strut by a head at one or both ends. The marker is attached to the strut by a process that includes forming a rivet from a radiopaque bead and attaching the rivet to the marker including deforming the rivet to enhance resistance to dislodgement during crimping or balloon expansion. The strut has a thickness of about 100 microns.

Claims

1. A medical device, comprising:

a scaffold having a thickness t and a pattern of elements forming a tubular body, the elements comprising struts, wherein at least one of the struts comprises;

a hole, and

a rim at least partially surrounding the hole, wherein a width D of the rim is measured from an edge of the hole to an outer edge of the strut; and

a radiopaque marker including a shank located within the hole and a head outside the hole, the head including a flange disposed on a surface of the rim,

wherein a length of the flange, measured from the edge of the hole and in a direction towards the outer edge of the strut, is greater than ½

D in order to resist a push-out force applied to the rim surface, and less than D to avoid vessel irritation when the scaffold is implanted within a vessel; and

wherein the scaffold thickness t is related to a length L of the marker measured between a first surface and a second surface of the marker by 1.1≤

L/t≤

1.8.

2. The medical device of claim 1, wherein the scaffold thickness t is between 80 and 120 microns and the strut comprises poly(L-lactide).

3. The medical device of claim 1, wherein the rim is curved and the width D is a radial distance measured relative to a center of the hole.

4. The medical device of claim 1, wherein the hole is a tapered hole and the shank is a frustum.

5. The medical device of claim 1,

wherein the head is disposed at a first opening located at a first side of the hole and a tail of the shank is disposed at a second opening located at a second side of the hole, and

wherein the second opening is larger than the first opening.

6. The medical device of claim 1, wherein the scaffold comprises poly(L-lactide).

7. The medical device of claim 1, wherein the radiopaque marker comprises platinum, iridium, tantalum, palladium, tungsten, niobium, zirconium, iron, zinc, magnesium, manganese, or alloys thereof.

8. The medical device of claim 1, wherein the hole is a tapered hole.

9. The medical device of claim 1, wherein the hole is a polygonal hole or an elliptical hole.

17. The medical device of claim 1, wherein the length of the flange is between ½

D and 90% of D.

18. The medical device of claim 1, wherein the marker is a first marker and the hole is a first hole, the strut further comprising:

a second hole and a second radiopaque marker having a shank within the hole, a head located outside the hole, the head including a flange disposed on a surface of rim of the hole, wherein a distance between the second marker flange and the first marker flange is between 0 and ¼

D.

19. The medical device of claim 1, wherein L is less than 160 microns.

10. A medical device, comprising:

a scaffold made from a polymer comprising poly(L-lactide) and having a pattern of elements forming a tubular body, the elements comprising struts, wherein at least one of the struts comprises;

a thickness of between 80 microns and 120 microns measured from a first surface of the strut to a second surface of the strut,

a width to thickness ratio of 1.2 to 2.0, and

a hole in the strut; and

a radiopaque marker disposed in the hole, the marker including a head having a flange disposed at the first surface and a shank disposed at the second surface;

wherein the radiopaque marker has a volume of about 6.76=10⁶ cubic micro-meters; and

wherein the radiopaque marker resists a push-out force of about 78 grams-force acting on the second surface.

11. The medical device of claim 10, wherein the radiopaque marker comprises platinum, iridium, tantalum, palladium, tungsten, niobium, zirconium, iron, zinc, magnesium, manganese or alloys thereof.

12. A medical device, comprising:

a scaffold made from a polymer comprising poly(L-lactide) and having a pattern of elements forming a tubular body, the elements comprising struts,

wherein at least one of the struts comprises;

a thickness t of between 80 microns and 120 microns measured from a first surface of the strut to a second surface of the strut, and

a hole in the strut; and

a radiopaque marker disposed in the hole, the marker including a head having a flange disposed at a first opening and a shank disposed at a second opening;

wherein the second opening is larger than the first opening; and

wherein the shank takes the shape of a frustum.

13. The medical device of claim 12, wherein the thickness t is related to a length L of the marker measured between a first surface and a second surface of the marker by 1.1≤

L/t≤

1.8.

14. The medical device of claim 12, wherein the radiopaque marker comprises platinum, iridium, tantalum, palladium, tungsten, niobium, zirconium, iron, zinc, magnesium, manganese, or alloys thereof.

15. The medical device of claim 12, wherein the strut has a width, and a ratio of the strut width to the strut thickness is about 1.2 to 2.0.

16. The medical device of claim 12, wherein the hole is a polygonal hole or an elliptical hole.