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

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.

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=10 6 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.

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.